WO2019087322A1 - Dc power feeding system - Google Patents

Abstract

The present invention slows down the degradation of a storage battery. Every time chargeable power Wc and weather forecast information Dwf are obtained, a power management device 9 calculates a planned charging power Wcp to a storage battery 11, an estimated generating power Wgf in a power generation device 3b, and estimated load powers Wlfa, Wlfb in load devices 71a, 71b in the next cycle, and compares the total power Wsm of the powers Wlfa, Wlfb, Wcp with the estimated generating power Wgf. When it is determined that the estimated generating power Wgf is larger than the total power Wsm, in this cycle, the power management device 9 instructs a bidirectional DC/DC converter 14 to supply power of an amount corresponding to the planned charging power Wcp to the storage battery 11, instructs DC/DC converters 5a, 5b to supply power of an amount corresponding to the estimated load powers Wlfa, Wlfb to the load devices 71a, 71b, and instructs the power generation device 3b to reduce generating power by an amount corresponding to the difference between the estimated generating power Wgf and the total power Wsm.

Description

DC power supply system

The present invention relates to a stand-alone DC power supply system not connected to a commercial power supply.

As a direct current feed system of this type, a direct current feed system disclosed in Patent Document 1 below is known. The DC power feeding system includes a natural energy power generation device, a load device having a regulation load and operating with generated power from the natural energy power generation device, and a storage battery connected to the natural energy power generation device and the load device to perform charging and discharging. A stand-alone power supply system including a power storage device, wherein the stand-alone power supply system calculates demand forecast data of a load device and generation output forecast data of a natural energy power plant using the weather forecast data, and the demand When it is predicted by the prediction data and the power generation output prediction data that the storage battery is charged beyond the maximum charging power of the storage battery, the power generation output from the natural energy power generation device is suppressed.

According to this independent power supply system, when it is predicted that the storage battery is charged by exceeding the maximum charge power of the storage battery by the demand forecast data and the power generation output forecast data, the power generation output from the solar power generation apparatus is Since the control is performed, it is possible to control so as not to exceed the maximum charging power of the storage battery.

WO 2013/128731 (page 2, 13; Figure 1)

However, in the known DC feeding system including the above-described conventional DC feeding system, when it is predicted that the storage battery is charged beyond the maximum charging power of the storage battery, the power generation output from the solar power generation device is suppressed Although this configuration is not clear, there is a problem in extending the life of the storage battery because the storage battery may be charged with the maximum charging current because it is unclear how to suppress it.

This invention is made in view of the said subject, and it aims at providing the direct current | flow electric power feeding system which can slow deterioration of a storage battery.

In order to achieve the above object, in the direct current feed system according to the present invention, a direct current bus serving as a bus bar for direct current feed, a power generating device generating power based on natural energy, and the generated power of the power generating device is supplied to the DC bus. It is connected between the first converter, the storage battery, the storage battery, and the DC bus, and the generated power supplied to the DC bus and the charging power of the storage battery are bi-directionally converted to power, Bi-directional converter for supplying power from the DC bus to the storage battery or from the storage battery to the DC bus, and voltage converting DC power of at least one of the generated power and the charging power supplied to the DC bus A second converter for supplying the load equipment, a power generation log including a weather condition and generated power when the power generation apparatus is operated, and the load equipment is operated Control unit which acquires a load log including the current weather condition and load power, and sequentially acquires the chargeable power of the storage battery and the weather prediction information at a predetermined acquisition time, the control unit Charge power calculation processing for calculating, based on the chargeable power and the weather forecast information, scheduled charge power for the storage battery in a period until the acquisition time that arrives next, each time the chargeable power and the weather forecast information are acquired; Generated power prediction processing for calculating predicted power generation of the power generation apparatus in the period based on the power generation log and the weather prediction information; predicted load power on the load device in the period is the load log and the weather prediction information Load power prediction processing calculated based on the total power of the predicted load power and the planned charging power and The electric power comparison process of comparing with the predicted generated power is executed, and when it is determined in the electric power comparison process that the predicted generated power is larger than the total power, the storage battery is sent to the storage battery with respect to the bidirectional converter in the period. Charge / discharge control processing for supplying power for planned charging power, load device control processing for supplying power for the predicted load power to the load device with respect to the second converter, and the generated power for the power generation device Power generation device control processing is performed to reduce the difference power between the predicted power generation and the total power.

According to the present invention, when it is predicted that the predicted generated power in the period until the next arriving acquisition time will be larger than the total power, the total generated power of the power generation apparatus is smaller than the predicted generated power in this period Since control is made to the same power as power, the actual charging power supplied to each storage battery can be suppressed to the same as scheduled charging power, and as a result, the power allocated to charging the storage battery becomes too large (that is, the charging current is It is possible to avoid the fact that the maximum current value or a large current value in the vicinity of the maximum current value) can be avoided, thereby avoiding the occurrence of a situation where the deterioration of the storage battery is accelerated. Thereby, deterioration of the storage battery can be delayed.

According to the present invention, it is possible to slow the deterioration of the storage battery charged by the natural energy power generation device.

FIG. 1 is a block diagram of a DC power supply system 1; FIG. 14 is an explanatory diagram for describing first to fourth processing contents of charge / discharge control processing, load device control processing, and power generation device control processing. FIG. 6 is an explanatory diagram for explaining an operation of the DC power supply system 1; FIG. 7 is another explanatory view for explaining the operation of the direct current feed system 1;

Hereinafter, an embodiment of a direct current feed system will be described with reference to the attached drawings. The direct current feed system is not limited to the following embodiments. Further, the components described below include those which can be easily conceived by those skilled in the art, and substantially the same components, and the components can be appropriately combined.

First, the configuration of the direct current feed system 1 as a direct current feed system will be described.

The DC power supply system 1 includes a DC bus 2 and one or more power generation devices 3 (in the present example, two power generation devices 3a and 3b, hereinafter referred to as “power generation device 3” if not distinguished). Correspondingly arranged first converter 4 (two power conditioners 4a and 4b described later as an example in this example), one or more load devices 71 (one example in this example) connected to DC power supply system 1 As second load devices 71a and 71b (hereinafter also referred to as "load devices 71" when not distinguished from each other) second converters 5 (in this example, two second converters 5a and 5b described later as an example) . hereinafter, when no distinction is also referred to as "second converter 5"), a plurality of direct-current power supply 6 (DC power supply device _{6 1,} 6 2, · · _{·, 6} n), the third converter 7, Contact And a power management device 9, generates a DC voltage based on the power generated by the power generation device 3, and is not connected to a standalone DC power supply system (commercial AC power supply) capable of supplying the load device 71. It is configured as a DC power supply system).

The DC bus 2 is laid over the installation place of the power generation device 3, the installation place of each DC power supply 6, and the installation place of the load device 71, and functions as a bus bar of DC power supply. Further, DC bus 2 has a predetermined voltage including a nominal bus voltage as a result of control of charge / discharge operation of bidirectional DC / DC converter 14 in a plurality of DC power supply devices 6 described later by power management device 9. The bus voltage Vbs is defined within a range (for example, within a voltage range of DC 350 V or more and DC 400 V or less including DC 370 V as a nominal bus voltage).

The power generation device 3 is configured of a distributed power supply device. In this case, the distributed power supply unit is configured of a power generation unit using natural renewable energy such as a solar power generation unit, a wind power generation unit, or a hydroelectric generation unit, or an engine type power generation unit using fossil energy such as light oil and gasoline. It is possible. In this example, for easy understanding, as one example, the engine-type power generation device 3a and the power generation device 3b using natural regenerated energy are configured.

The power generation device 3a is started and stopped by an operation (manually) by the operator, and generates and outputs an AC voltage V1 of a predetermined voltage value in an operation state. The power management apparatus 9 can also control start / stop. In addition, the power generation device 3a is included in the plurality of DC power supply devices 6, such as at the time of the first startup of the DC power supply system 1, and at the time of restart after the DC power supply system 1 stops for a long time. When a large amount of charging power is temporarily required to charge the storage battery 11, the storage battery 11 is operated only for a predetermined period. Therefore, as an example in this example, the power generation device 3a can sufficiently charge the storage battery 11 while supplying necessary load power to the load device 71 in each cycle T described later included in the fixed period. It is assumed that electric power (predetermined known generated power Wgap) is generated to be able to be supplied to the DC bus 2 via the corresponding power conditioner 4a described later. Further, for example, by adopting a configuration such as outputting to the power management device 9 a state signal indicating that the power generation device 3a is in operation in the operating state, the power management device 9 can detect the operation / stop of the power generation device 3a. Is configured.

In addition, the power generation device 3b is configured of a solar power generation device as an example, and automatically generates power in the daytime to generate and output a DC voltage V2b. In this case, the position of the operating point on the PV curve can be controlled by the corresponding power conditioner 4b described later. Further, with this configuration, the power generation device 3b is configured to be able to control the power (generated power Wgbp) supplied to the DC bus 2 through the power conditioner 4b in each cycle T.

The first converter 4 is composed of two power conditioners 4a and 4b arranged corresponding to the two power generation devices 3a and 3b in this example. In the present embodiment, as an example, power conditioner 4a is configured to include an AC / DC converter, and is disposed corresponding to power generation device 3a. The power conditioner 4a operates with the DC voltage internally generated based on the AC voltage V1, and is controlled by the power management device 9 to generate the AC voltage V1 as the generated power output from the power generation device 3a as a bus. The voltage is converted into a voltage Vbs and supplied to the DC bus 2.

Power conditioner 4b includes a DC / DC converter as an example, and is disposed corresponding to power generation device 3b. Further, the power conditioner 4b operates with the DC voltage generated internally based on the DC voltage V2b, and converts the DC voltage V2b as generated power output from the power generation device 3b into the bus voltage Vbs Supply to 2. Further, the power conditioner 4b is controlled by the power management device 9 and is in a state where the power generation efficiency of the power generation device 3b composed of the solar power generation device is the highest (the operating point is a peak on the PV curve (optimum operation Normal operation to generate electric power Wgbp at maximum) and generated electric power Wgbp instructed from power management device 9 (generated electric power Wgbp in this case is generated electric power at the optimum operating point) Power reduction (suppression) operation to operate the power generation device 3b).

The second converter 5 is configured of, for example, a DC / DC converter that operates with a DC voltage generated internally based on the bus voltage Vbs. In this example, for easy understanding, it is assumed that the load devices 71 (DC loads) connected to the DC power supply system 1 are two load devices 71a and 71b, and the second converter 5 is a load device 71a. And a second converter 5b (also referred to as a DC / DC converter 5b) corresponding to the load device 71b. In this case, the DC / DC converter 5a is controlled by the power management device 9 to convert the bus voltage Vbs into a load voltage VLa which is a DC voltage used by the load device 71a (DC voltage conversion). Supply to The DC / DC converter 5a also has a current limiting function of limiting the load current supplied from the DC bus 2 to the load device 71a with the upper limit current value set from the power management unit 9.

Similar to the DC / DC converter 5a, the DC / DC converter 5b is controlled by the power management device 9 to convert the bus voltage Vbs into a load voltage VLb which is a DC voltage used by the corresponding load device 71b (DC Voltage conversion) to supply the load device 71b. Further, the DC / DC converter 5 b has a current limiting function of limiting the load current supplied from the DC bus 2 to the load device 71 b with the upper limit current value set from the power management device 9.

The load devices 71a and 71b are DC loads that operate by receiving the supply of load voltages VLa and VLb (hereinafter also referred to as load voltage VL unless otherwise specified), which are DC voltages. , 71b are constituted by lighting devices operating with DC voltage, household appliances such as a television and a refrigerator operating with DC voltage, and information devices such as a personal computer and a portable terminal operating with DC voltage.

DC power supply device 6 includes a DC power supply device 6 _1, 6 _2, · · ·, n-number of 6 _n (n is an integer of 2 or more. Or less, particularly when no distinction is also referred to as a DC power supply device 6) is disposed There is. Each DC power supply device 6 is configured to include a storage battery 11, a battery management unit (BMU (Battery Management Unit)) 12, a contactor 13 and a bidirectional DC / DC converter 14, respectively. The storage batteries 11 ₁ , 11 ₂ ,..., 11 _n (hereinafter, also referred to as the storage battery 11 when not distinguished in particular) are formed of lithium ion batteries as an example, but are not limited thereto. It can also be configured with a hydrogen battery and a NAS battery (sodium-sulfur battery). Each storage battery 11 has a prescribed power capacity (nominal capacity), and is configured to be capable of charge operation and discharge operation within a predetermined working voltage range including a nominal voltage.

Further, although one of the storage batteries 11 (in the example, the storage battery 11 _{1 in the} example) is also used for supplying power to the DC bus 2, the BMU 12 of each of the DC power supply devices 6 ₁ to 6 _n The battery mainly functions as a storage battery for supplying power (operation voltage Vop) for the operation of the contactor 13 and the power management apparatus 9. Therefore, the storage battery 11 _1, corresponding bidirectional DC / DC converter 14 ₁ is in the operating state, and through the contactor 13 ₁ in the coupled state are connected to a bidirectional DC / DC converter 14 ₁ In the operating state, charge and discharge control is performed by power management device 9 such that charge voltage Vba is less than the upper limit value of the working voltage range and equal to or higher than the voltage threshold (predetermined voltage value) exceeding the lower limit value. .

_{BMU12 1, 12 2, ···,} 12 n ( hereinafter, especially when no distinction is also referred to as BMU12), each storage battery _{11 1,} 11 2 corresponding, ..., are respectively disposed 11 _n, later Operate with the operating voltage Vop. In addition, each BMU 12 measures the charge voltage Vba of the storage battery 11 as an example, and calculates the SOC (State of charge) by measuring the current value of the charge / discharge current of the storage battery 11 in the operating state. And the function of outputting information including the measured charging voltage Vba, the current value of the charging / discharging current, and the calculated SOC to the power management apparatus 9 as battery information. Further, when the BMU 12 receives the contactor control information from the power management apparatus 9, the BMU 12 executes the control contents indicated by the contactor control information to the contactor 13 (when the control content is a cutoff instruction, the contactor 13 shifts to the cutoff state). When the control content is a connection instruction, the contactor 13 is also brought into a connected state.

Contactor _{13 1,} 13 2, ..., 13 _n (hereinafter, when not particularly distinguished, also referred to as contactor 13), the corresponding storage battery _{11 1,} 11 2, ..., and positive and negative 11 _n, corresponding .., 14 _n are disposed between the storage batteries 11 ₁ , 11 ₂ ,..., 11 _n on the side of the storage batteries 11 ₁ , 14 ₂ ,. Operate with the operating voltage Vop. Each contactor 13 is controlled by the corresponding BMU 12 to shift to any one of the blocking state and the coupling state, and in the blocking state, the positive electrode and the negative electrode, and the pair of input / output terminals Are cut off (disconnected), and in the connected state, the positive electrode and the negative electrode are connected to the pair of input / output terminals.

The bi-directional DC / DC converters 14 ₁ , 14 ₂ ,..., 14 _n (hereinafter also referred to as bi-directional DC / DC converter 14 when not particularly distinguished) are a pair of input / output of the storage battery 11 side as described above. The terminals (one pair of input / output terminals) are connected to the storage battery 11 via the contactor 13 and the other pair of input / output terminals are connected to the DC bus 2 so that the storage battery 11 and the DC bus 2 It is connected (arranged) between. In addition, the bidirectional DC / DC converter 14 performs CV operation (constant voltage charging / discharging operation) with a DC voltage generated internally based on the bus voltage Vbs, and is operation controlled by the power management device 9. Specifically, when the control information received from power management device 9 indicates a charge instruction, bi-directional DC / DC converter 14 boosts or reduces (voltage conversion) bus voltage Vbs input from the other pair of input / output terminals. Then, the direct current constant current is supplied to the storage battery 11 for charging by performing output to the storage battery 11 from one pair of input / output terminals (charging operation is performed). Thereby, the bus voltage Vbs of the DC bus 2 is lowered. On the other hand, when the received control information is a discharge instruction, bidirectional DC / DC converter 14 boosts or lowers (converts voltage) the charging voltage Vba of storage battery 11 input from one pair of input / output terminals to set the other pair. The storage battery 11 is discharged with a DC constant current by performing output to the DC bus 2 from the input / output terminal of (a discharge operation is performed). Thus, the bus voltage Vbs of the DC bus 2 is raised. The bi-directional DC / DC converter 14 can be configured by, for example, a known bi-directional DC / DC converter disclosed in JP-A-2016-152641.

The bidirectional DC / DC converter 14 also has a current limiting function of limiting each current value of the charging current supplied to the storage battery 11 and the discharge current discharged from the storage battery 11 to the maximum current value or less of the storage battery 11.

The third converter 7 is configured of a DC / DC converter (hereinafter, also referred to as a DC / DC converter 7). Further, DC / DC converter 7, the positive electrode and the negative electrode thereof a pair of input terminals of the storage battery 11 ₁ of the DC power supply device _61, and is connected without passing through the contactor 13 _1, the charging voltage Vba of the battery 11 ₁ Operate. In addition, DC / DC converter 7 boosts or lowers (converts voltage) the charging voltage Vba of storage battery 11 in the operating state, so that BMU 12 and contactor 13 of each DC power supply device 6 and power management device 9 The operation voltage Vop to be used is generated and output.

The power management device 9 is configured by a computer operating at the operation voltage Vop and functions as a control unit. Further, the power management apparatus 9 generates a power generation log for the power generation device 3b using natural regenerated energy (the weather condition is associated with the power generation when the power generation device 3b operates at the optimum operating point in this weather condition) Past log) Drg 1 and load log for each load device 71 a, 71 b (each past log in which the weather conditions when the load devices 71 a, 71 b operate and the load power at that time are associated) An acquisition process for acquiring Drg2 (hereinafter, also referred to as first acquisition process to distinguish) is executed. In addition, the power management apparatus 9 defines in advance an acquisition process (hereinafter, also referred to as a second acquisition process to distinguish) for acquiring weather prediction information Dwf for an area (area) including the installation place of the power generation device 3b. Execute at acquisition time. In this example, as an example, the acquisition time is defined as the time of arrival at a predetermined cycle T (one hour in this example) defined in advance, such as 1:00, 2:00,. Therefore, in the present example, the power management apparatus 9 executes the second acquisition process at a cycle T (for example, at an hour interval).

As an example, the power management apparatus 9 includes a communication apparatus connectable to a network such as the Internet or a local area network, executes the first acquisition processing, and generates the above power generation log Drg1 and load log from an external server via the network. Drg2 is acquired and stored, and the second acquisition processing is executed to acquire and store the above-described weather prediction information Dwf from the weather data distribution site via the network.

The weather forecast information Dwf is, for example, weather forecast data for one day starting from a cycle T arriving after the current cycle T (that is, the latest weather forecast data for one day starting from the next cycle T) Information that can predict the amount of solar radiation to the power generation device 3b (for example, information indicating whether it is daytime or nighttime (is it a solar radiation period), and information indicating weather such as sunny, cloudy, or rain And the like, and, together with the predicted amount of solar radiation, includes information (such as temperature) necessary to predict the power generated by the power generation device 3b (power generated at the optimum operating point). Do. That is, the power management apparatus 9 acquires, at a cycle T, the weather prediction information Dwf including the latest information described above. In this example, since the power generation device 3b is configured by a solar power generation device, the weather prediction information Dwf is configured to include information capable of predicting the amount of solar radiation, but the power generation device 3b is a wind power generation device. When configured, the weather prediction information Dwf is configured of information that can predict the power generated by the wind turbine generator, such as the wind volume (wind speed).

In addition, the power management apparatus 9 executes an acquisition process (hereinafter also referred to as a third acquisition process to distinguish) for acquiring the chargeable electric power Wc of each storage battery 11 at a cycle T. In the third acquisition process, the power management apparatus 9 first acquires the battery information output from each BMU 12, and then, the SOC of each storage battery 11 included in the acquired battery information and the rating of each known storage battery 11 Based on the capacity, the chargeable power Wc (= rated capacity-SOC) of each storage battery 11 is calculated and acquired. Thus, the power management apparatus 9 acquires the latest chargeable power Wc for each storage battery 11 at a cycle T.

The power management apparatus 9 executes charge power calculation processing, generated power prediction processing, load power prediction processing, and power comparison processing each time the weather prediction information Dwf and the chargeable power Wc are acquired (every cycle T).

In this case, in the charge power calculation process, the power management device 9 calculates the scheduled charge power Wcp for each storage battery 11 in the cycle T that arrives next, based on the weather prediction information Dwf and the chargeable power Wc.

Specifically, in the charging power calculation process in the stopped state of the power generation device 3a, the power management apparatus 9 first includes a solar radiation period (period from dawn to sunset) (daytime) included in the weather prediction information Dwf. It is detected whether the next period T is included in the solar radiation period based on the information on. Then, when the result of this detection is that the next cycle T is included in the solar radiation period, the power management apparatus 9 specifies a continuous period starting from the next cycle T and ending simultaneously with the end of the solar radiation period. Identified as a sunshine period.

Also, when the specific sunshine period is specified in this way, the power management apparatus 9 determines how many cycles T are included in the specific sunshine period (the number of specific sunshine periods is m (m is a positive integer)). Calculate that consists of T). The power management unit 9, the storage battery _{11 1,} 11 2, ..., chargeable power _{Wc 1,} Wc 2 of 11 _n, ..., by dividing each _{Wc n} in this number m, the specific Scheduled charge powers Wcp ₁ , Wcp ₂ ,..., Wcp _n for charging the storage batteries 11 ₁ , 11 ₂ ,..., 11 _n in each cycle T (including the next cycle T) included in the sunshine period = Calculate chargeable power Wc ₁ / m, Wc ₂ / m, ..., Wc _n / m). Below, chargeable power _{Wc 1, Wc 2, ···,} for the _{Wc n,} in particular, also referred to as a rechargeable electric power Wc when no distinction, planned charging power _{Wcp 1, Wcp 2, ···,} will also Wcp _n, particularly distinguished Also referred to as scheduled charging power Wcp when not.

The reason why the chargeable power Wc is dispersed in each cycle T included in the specific sunshine period in this manner is that the storage batteries 11 are completely filled at the end of the specific sunshine period as compared with the case where they are not dispersed. It is because the possibility that the current value of the charging current to the storage battery 11 can be made lower than the maximum current value can be increased while transitioning to the charging state. The SOCs of the storage batteries 11 ₁ , 11 ₂ ,..., 11 _n at the start of the specific sunshine period may differ depending on the storage battery 11 depending on the charge / discharge state of each battery. even capacity are the same, chargeable power _{Wc 1,} Wc 2, ..., _{Wc n} battery _{11 1,} 11 2, ..., may be different for each 11 _n. In this example, each chargeable power Wc is distributed to the same m periods T in a common specific sunshine period (divided into m), and the planned charge power Wcp (the planned charge power Wcp is the chargeable power Wc). By proportionally charging, each storage battery 11 which may have a different SOC is gradually shifted to a fully charged state in a common specific sunshine period.

Therefore, when the sunshine duration is 8 h, although the specific sunshine duration decreases by one cycle T (one hour each) like 8 h, 7 h, ..., each time one cycle T elapses, Since the SOC also increases by the scheduled charging power Wcp, the scheduled charging power Wcp for each cycle T in the sunshine period has a substantially constant value for each storage battery 11. For example, when the chargeable power Wc at the start of the sunshine period (8 h as an example) of one storage battery 11 is 16 kWh, the scheduled charge power Wcp in the first one cycle T (1 hour) is the specific sunshine period 8 h Therefore, the planned charging power Wcp in the next one cycle T (one hour) is 2 kW (= 16/8), but the specific sunshine time is 7 h, but only 2 kWh is charged, so 2 kW (= 14/7), and the planned charging power Wcp in the next one cycle T (1 hour) is 2 kW (= 12/6) because it is further charged by 2 kWh although the specific sunshine time is 6 h. The planned charging power Wcp remains constant at 2 kW until the last period T of the sunshine period.

Therefore, even if the storage battery 11 is of a specification capable of charging 5 kWh in one hour at the maximum current value, for example, a total of 16 kWh of electric power can be stored in the storage battery 11 every one hour such as 5 kWh, 5 kWh, 5 kWh, 1 kWh. The charging current of the storage battery 11 can be suppressed to less than the maximum current value as compared to the case of charging (in this case, the battery will be fully charged in the first 4 hours of the daylight hours 8h). ing.

In addition, when the power management device 9 detects that the above-described next period T is included in the solar radiation period when the power generation device 3a is in the stopped state, the result is not included in the solar radiation period. Since there is no specific sunshine period of (ie, the specific sunshine period is zero), the planned charging power Wcp in the next cycle T is calculated as zero.

On the other hand, in the charge power calculation process in each cycle T (that is, each cycle T included in the above-described fixed period for operating the power generation device 3a) in the operation state of the power generation device 3a, the power management device 9 A period starting from T and ending simultaneously with the end of this fixed period is specified as a specific charging period (continuous period). Further, the power management apparatus 9 calculates how many cycles T are included in the specific charge period (the specific charge period is composed of m periods T). The power management unit 9, the storage battery _{11 1,} 11 2, ..., chargeable power _{Wc 1,} Wc 2 of 11 _n, ..., by dividing each _{Wc n} in this number m, the specific Scheduled charging powers Wcp ₁ , Wcp ₂ ,..., Wcp _n for charging the storage batteries 11 ₁ , 11 ₂ ,..., 11 _n in each cycle T (including the next cycle T) included in the charging period = Calculate chargeable power Wc ₁ / m, Wc ₂ / m, ..., Wc _n / m). The reason why the chargeable power Wc is dispersed in each period T included in the specific charge period in this manner is the same as in the stop state of the power generation device 3a described above, as compared with the time when it is not dispersed. Because it is possible to increase the possibility that the current value of the charging current to the storage battery 11 can be made lower than the maximum current value while making each storage battery 11 shift to the full charge state just at the end of the specific charging period. is there.

Further, in the DC power feeding system 1, as described later, in the operating state of the power generation device 3a, the generated power in the power generation device 3b is not supplied to the DC bus 2, and the power generation device 3b is in the stopped state of the power generation device 3a. It is configured to work only when. Therefore, the power management apparatus 9 uses the known generated power Wgap as the predicted generated power Wgf of the power generation apparatus 3a in the next cycle T in the generated power prediction process when the power generation apparatus 3a is in the operating state. .

In the power generation prediction process when the power generation device 3a is in the stopped state, the power management device 9 is based on the power generation log Drg1 and the weather prediction information Dwf for the predicted power generation Wgf in the power generation device 3b in the next cycle T described above. Estimate and calculate. In this case, if the result of detecting whether the next cycle T is included in the solar radiation period in the above charging power calculation process is not included in the solar radiation period, that is, the above-mentioned specific sunshine period is If not present, the predicted generated power Wgf is calculated to be zero.

Further, in the load power prediction process, the power management apparatus 9 calculates the predicted load powers Wlfa and Wlfb for the load devices 71a and 71b in the next cycle T, the load log Drg2 for the load devices 71a and 71b, and the weather prediction information Calculated based on Dwf.

Further, in the power comparison process, the power management apparatus 9 sums the predicted load power Wlf at each load device 71a, 71b (Wlfa + Wlfb) and the scheduled charge power Wcp at each storage battery 11 (Wcp ₁ + Wcp ₂ +. · Calculate the total power Wsm of + Wcp _n ) and compare the calculated predicted generated power Wgf with the total power Wsm to obtain a comparison result (determine the magnitude relationship between the predicted generated power Wgf and the total power Wsm) . Further, in the power comparison process, the power management apparatus 9 compares the sum of the predicted load power Wlf and the predicted generated power Wgf to obtain the comparison result (size of predicted load power Wlf and predicted generated power Wgf Determine the relationship).

Further, the power management device 9 executes charge / discharge control processing for each DC power supply device 6, load device control processing for each load device 71, and power generation device control processing for the power generation device 3b from the beginning of the arriving cycle T. The power management device 9 also executes a voltage measurement process of measuring the bus voltage Vbs. In this case, the power management apparatus 9 can adopt a configuration in which the bus voltage Vbs is directly measured, and for example, the first converter 4 (at least one of the power conditioners 4a and 4b) receives the bus voltage Vbs. It is also possible to employ a configuration in which the power management apparatus 9 indirectly measures the bus voltage Vbs via the first converter 4 so as to have a function of measuring and outputting to the power management apparatus 9.

Next, the operation of the DC power supply system 1 will be described. Note that the storage battery 11 _1, since they are used to power components, such as power management apparatus 9, as described above, the charging voltage Vba is less than the upper limit of the voltage range, and more voltage threshold It shall be charged beforehand so that it may become. Also, each contactor 13 is initially in the disconnected state.

In this DC power feeding system 1, for example, at the time of the first start of the DC power feeding system 1 or at the time of restarting after the long-term stop of the DC power feeding system 1, other storage batteries 11 ₂ to 11 _n excluding the storage battery 11 ₁ When it is assumed that the battery is in the overdischarged state (the state where the charging voltage Vba falls below the lower limit value of the working voltage range), first, the power generation device 3a is operated for a certain period to output the AC voltage V1.

For this reason, first, the operation of the DC power feeding system 1 when operating the power generation device 3a will be described. In this case, the power conditioner 4 a operates by receiving the supply of the AC voltage V 1, converts the AC voltage V 1 into the bus voltage Vbs, and supplies the bus voltage V bs to the DC bus 2. Therefore, the bus voltage Vbs of the DC bus 2 rises within a predetermined voltage range (voltage range of DC 350 V or more and DC 400 V or less).

Moreover, if it is daytime, it will be in the state which the power generation device 3b can generate power, but as above mentioned in this example, the power generation device 3a is required with respect to the load apparatus 71 in each period T included in this fixed period. When the power generation device 3 b is operated to generate power, the storage battery 11 is configured to be able to generate power sufficient to charge the storage battery 11 (predetermined known generation power Wgap) while supplying appropriate load power. The power allocated to charging the battery becomes too large. In this case, since the bidirectional DC / DC converter 14 of this example is configured to perform the CV operation, the charging current to the storage battery 11 will be too large, and the deterioration of the storage battery 11 will be accelerated. In order to avoid this, when the power management device 9 detects that the power generation device 3a is in operation based on the state signal output from the power generation device 3a, the power management device 9 executes control for the power conditioner 4b. The supply of the generated power Wgbp of the power generation device 3b to the DC bus 2 is stopped (the power generation operation of the power generation device 3b may be stopped). That is, in the DC power supply system 1, only the power generation device 3a supplies power to the DC bus 2 at the time of the first start or restart after long-term stop, and power generation to the DC bus 2 only at other times Supply.

In the DC power supply system 1, DC / DC converter 7 from the storage battery 11 ₁ and is supplied with a charging voltage Vba is operated day and night, and BMU12 and contactor 13 of each DC power supply device 6, the power management apparatus 9 The operation voltage Vop is output (supplied) at the same time. Therefore, the BMU 12 and the contactor 13 of each DC power supply 6 and the power management unit 9 are in operation. Therefore, BMUs 12 ₁ to 12 _n of DC power supply devices 6 ₁ to 6 _{n in} the operating state periodically charge voltage Vba etc. for corresponding storage batteries 11 ₁ to 11 _n (for example, a cycle shorter than cycle T) Or at the same cycle as cycle T) and output to the power management unit 9 as battery information.

Further, the power management apparatus 9 in the operating state executes, for example, the first acquisition process once at the time of the first activation of the DC power feeding system 1 to acquire and store the power generation log Drg1 and the load log Drg2. In this example, as an example, since the power generation log Drg1 and the load log Drg2 are configured of past logs for one year, the configuration of the DC power feeding system 1 does not change, and the weather condition at the installation site does not change significantly. As long as it is possible, for example, the power generation log Drg1 and the load log Drg2 acquired in the first acquisition processing executed only once at the time of startup can be used continuously even after the second year. The configuration for acquiring the power generation log Drg1 and the load log Drg2 is not limited to this configuration, and for example, a predetermined period such as several weeks, several months, or a year may be (1) Acquisition processing may be executed and acquired.

After that, the power management apparatus 9 charges / discharges each processing content in the charge / discharge control processing, the load device control processing, and the power generation device control processing while defining each processing T based on the information obtained in the immediately preceding cycle T. An operation to execute control processing, load device control processing, and power generation device control processing is started. In addition, the power management apparatus 9 performs the above-described information for defining the contents of processing in charge / discharge control processing, load device control processing, and power generation device control processing to be executed in the next coming cycle T (next cycle T). The information acquisition process of acquiring is executed every cycle T.

In this information acquisition process, the power management apparatus 9 performs a second acquisition process of acquiring weather forecast information Dwf, a third acquisition process of acquiring chargeable power Wc for each storage battery 11, and the acquired chargeable power Wc. Charge power calculation processing for calculating scheduled charge power Wcp for each storage battery 11, generated power prediction processing for calculating predicted generated power Wgf in the power generation devices 3a and 3b based on the acquired weather prediction information Dwf and the power generation log Drg1 etc. Load power prediction processing for calculating predicted load power Wlf at each load device 71a, 71b based on the acquired weather prediction information Dwf and load log Drg2, and total power Wsm (= total of predicted load power Wlf + each storage battery 11 Of the estimated charge power Wcp) and the predicted generated power Wgf and the sum of the predicted load power Wlf Run the power comparison process for obtaining a result of comparison between the measured power generated WGF, it acquires information for specifying the processing content in executing the next cycle T charge and discharge control process and the load device control.

This information includes the cycle T in the solar radiation period together with the planned charging power Wcp in the incoming cycle T, the predicted generated power Wgf in the cycle T, and the predicted load power Wlf in the cycle T described above. Information indicating the comparison result of the predicted generated power Wgf and the total power Wsm, and the information indicating the comparison result of the sum of the predicted load power Wlf and the predicted generated power Wgf. When the power generation device 3a is in operation, the generated power Wgap in the power generation device 3a becomes the predicted generated power Wgf. Therefore, the information indicating the comparison result of the predicted generated power Wgf and the total power Wsm is the predicted power generation. It shows the comparison result that the power Wgf is larger than the total power Wsm.

The processing contents in the charge / discharge control processing and the load device control processing are divided into the following four processing contents from the first processing contents to the fourth processing contents based on the respective information acquired in the immediately preceding cycle T ((4) See Figure 2). The first processing content among them is the processing content when the comparison result of the predicted generated power Wgf and the total power Wsm is the comparison result that the predicted generated power Wgf is larger than the total power Wsm, and the second processing content Is the processing content when the comparison result between the predicted generated power Wgf and the total power Wsm is the comparison result that the predicted generated power Wgf matches the total power Wsm, and the third processing content is the total with the predicted generated power Wgf The comparison result with the power Wsm is a comparison result that the predicted generated power Wgf is smaller than the total power Wsm, and the comparison result between the predicted load power Wlf and the predicted generated power Wgf is a predicted generated power Wgf The processing content in the case of the comparison result of being larger than the total of the predicted load power Wlf, and the fourth processing content is that the comparison result of the predicted generated power Wgf and the total power Wsm is the predicted generation The comparison result that the power Wgf is smaller than the total power Wsm, and the comparison result between the sum of the predicted load power Wlf and the predicted generated power Wgf is that the predicted generated power Wgf is less than or equal to the total of the predicted load power Wlf It is the processing content at the time of a comparison result.

Specifically, when the first processing content corresponds to the above, since the predicted power generation Wgf is larger than the total power Wsm, the surplus power (the predicted power generation Wgf and the total power Wsm Differential power (= predicted generated power Wgf−total power Wsm) is generated. For this reason, in this state, the power allocated to charging the storage battery 11 becomes too large (beyond the planned charging power Wcp), which causes the bi-directional DC / DC converter 14 to perform CV operation. The charging current becomes too large, which may accelerate the deterioration of the storage battery 11. Therefore, when the power generation device 3 in operation is capable of controlling the power supplied to the DC bus 2 like the power generation device 3b, as shown in FIG. The power management device 9 generates the generated power Wgbp of the power generation device 3b from the predicted generated power Wgf with respect to the power conditioner 4b corresponding to the power generation device 3b from the above-mentioned difference power (= predicted generated power Wgf−total power Wsm) The control is performed to decrease the power generation amount Wgbp of the power generation device 3b with the total power Wsm (= the sum of the predicted load power Wlf + the sum of the scheduled charging power Wcp of each storage battery 11). is there. As a result, the power supplied to each storage battery 11 can be made the planned charging power Wcp.

Further, as shown in FIG. 2, in the charge / discharge control process, the first process content is to charge the bi-directional DC / DC converter 14 by supplying the scheduled charge power Wcp to the corresponding storage battery 11 for charging. It is processing content. In this charge / discharge control process, power management device 9 charges voltage Vba of each storage battery 11 included in the battery information acquired from BMU 12 of each DC power supply device 6 in the third acquisition process (for each storage battery 11 included in the battery information While specifying DC power supply device 6 having rechargeable storage battery 11 (storage battery 11 whose charge voltage Vba has not reached the upper limit value of the working voltage range) based on SOC, identified DC power supply device 6 The contact control information indicating the connection instruction to the BMU 12 is output from the beginning to the end of the current cycle T, and the charge instruction to the bidirectional DC / DC converter 14 of the DC power supply 6 (scheduled charging power Wcp Control information indicating an instruction to average the battery over the entire cycle T and charge the storage battery 11 is output.

Further, as shown in FIG. 2, in the load device control process, the first processing content is a load voltage VLa, which is used by the corresponding load devices 71a and 71b for each DC / DC converter 5a and 5b. The processing content is to cause the load devices 71a and 71b to supply the predicted load powers Wlfa and Wlfb while converting and outputting the bus voltage Vbs so as to be VLb.

Further, when the content of the second process is satisfied, since the predicted generated power Wgf matches the total power Wsm, the above-described surplus power is not generated in the predicted generated power Wgf. Therefore, as shown in FIG. 2, the second processing content refers to the power generation device control process when the operating power generation device 3 can control the power supplied to the DC bus 2 like the power generation device 3 b. The power management device 9 is a process for executing control to cause the power conditioner 4b corresponding to the power generation device 3b to generate the predicted generated power Wgf without reducing the generated power Wgbp of the power generation device 3b. . In addition, in the charge and discharge control process, the process content is to supply the scheduled storage power Wcp to the corresponding storage battery 11 to charge the bidirectional DC / DC converter 14. Further, in the load device control process, the bus voltage Vbs is converted and output to the DC / DC converters 5a and 5b so that the load voltages VLa and VLb used by the corresponding load devices 71a and 71b are obtained. In addition, the processing content is that the load devices 71a and 71b are supplied with the predicted load powers Wlfa and Wlfb.

Further, in the case where the above-described third processing content is applied, since the predicted generated power Wgf is larger than the total of the predicted load power Wlf, the predicted load power Wlfa, Wlfb can be supplied to the load devices 71a, 71b. Since the generated power Wgf is smaller than the total power Wsm, when the predicted load powers Wlfa and Wlfb are supplied to the load devices 71a and 71b, the charging power that can be supplied to each storage battery 11 is smaller than the scheduled charging power Wcp. Therefore, as shown in FIG. 2, the third processing content is, in the power generation device control process, when the operating power generation device 3 is capable of controlling the power supplied to the DC bus 2 like the power generation device 3 b. The power management device 9 is a process for executing control to cause the power conditioner 4b corresponding to the power generation device 3b to generate the predicted generated power Wgf without reducing the generated power Wgbp of the power generation device 3b. . Further, in the load device control process, the bus voltage Vbs is converted and output to the DC / DC converters 5a and 5b so that the load voltages VLa and VLb used by the corresponding load devices 71a and 71b are obtained. In addition, the processing content is that the load devices 71a and 71b are supplied with the predicted load powers Wlfa and Wlfb. Further, in the charge / discharge control process, although each scheduled storage power Wcp can not be charged to each storage battery 11, predicted generated power Wgf and predicted load power Wlf for each bidirectional DC / DC converter 14 are obtained. The processing content is, for example, evenly dividing and charging each storage battery 11 of the difference power of the sum of.

Further, in the case where the above-described fourth processing content is applied, the predicted generated power Wgf is less than or equal to the total of the predicted load power Wlf, so when trying to supply the predicted load power Wlfa, Wlfb to the load devices 71a, 71b, There is no electric power that can be used to charge the storage battery 11, and when the predicted generated power Wgf is less than the total of the predicted load power Wlf, it is necessary to discharge the storage batteries 11 in reverse. Therefore, as shown in FIG. 2, when the power generation device 3 in operation is capable of controlling the power supplied to the DC bus 2 as in the power generation device 3b, the fourth processing content is in the power generation device control processing. The power management device 9 is a process for executing control to cause the power conditioner 4b corresponding to the power generation device 3b to generate the predicted generated power Wgf without reducing the generated power Wgbp of the power generation device 3b. . Further, in the load device control process, the bus voltage Vbs is converted and output to the DC / DC converters 5a and 5b so that the load voltages VLa and VLb used by the corresponding load devices 71a and 71b are obtained. In addition, the processing content is that the load devices 71a and 71b are supplied with the predicted load powers Wlfa and Wlfb. Further, in the charge / discharge control process, the process content is to divide equally the respective storage batteries 11 to discharge the insufficient power (= sum of predicted load power Wlf−predicted generated power Wgf) generated in the predicted generated power Wgf. Specifically, in this charge / discharge control process, power management device 9 charges voltage Vba of each storage battery 11 included in the battery information acquired from BMU 12 of each DC power supply device 6 in the third acquisition process (included in battery information To identify the DC power supply device 6 having the rechargeable storage battery 11 (the storage battery 11 in which the charging voltage Vba has not reached the lower limit value of the working voltage range) based on the SOC of each storage battery 11 The contact control information indicating the connection instruction to the BMU 12 of the DC power supply 6 is output from the beginning to the end of the current cycle T, and the discharge instruction to the bidirectional DC / DC converter 14 of the DC power supply 6 ( Control information indicating an instruction for averaging the scheduled charging power Wcp over the entire cycle T and discharging the battery from the storage battery 11 is output.

The information indicating the comparison result of the predicted generated power Wgf and the total power Wsm indicates the comparison result that the predicted generated power Wgf is larger than the total power Wsm during the fixed period in which the power generation device 3a is operating. There is. Therefore, based on the comparison result, the power management apparatus 9 executes the charge / discharge control process and the load device control process with the above-described first control content. Further, in the power generation device control process, the power management device 9 detects that the power generation device 3a is in operation based on the state signal output from the power generation device 3a, and generates power for the power conditioner 4b. Control is performed to stop the supply of the generated power Wgbp of the device 3b to the DC bus 2 (the power generation operation of the power generation device 3b may be stopped).

Therefore, in the DC power supply system 1 when the power generation device 3a is operated, each storage battery 11 specified as being chargeable is charged for each period T corresponding to corresponding planned charging power Wcp, that is, for a fixed period The battery is charged using the entire range, and is shifted to a substantially full charge state at the end of a certain period. Power management device 9 determines whether or not charging voltage Vba included in the battery information output in a cycle T from BMU 12 of each DC power supply device 6 has reached the upper limit value of the operating voltage range (or included in the battery information). Of the DC power supply device 6 including the storage battery 11 when it is determined that the fully charged state has been detected while detecting whether the storage battery 11 has reached the full charge state). The contact control information indicating a shutoff instruction is output to the BMU 12, and the storage battery 11 is disconnected from the bidirectional DC / DC converter 14 by shifting the contactor 13 to the shutoff state. Thereby, overcharging of the storage battery 11 is prevented. The power management unit 9, upon charging of each battery ₁₁ 1 ~ 11 _n, which perform the charging of the battery 11 ₁ for outputting a charging voltage Vba to be used in generating operating voltage Vop preferentially. Thus, the storage battery 11 _1, the charging voltage Vba is always charged to be the upper limit vicinity of the voltage range.

Further, each DC / DC converter 5a, 5b operates so as to be able to supply corresponding load voltage VLa, VLb with corresponding predicted load power Wlfa, Wlfb to the corresponding load device 71a, 71b.

In each cycle T, the power management apparatus 9 performs the second acquisition process, the third acquisition process, the charge power calculation process, the generated power, and the power generation apparatus control process, the charge / discharge control process, and the load device control process described above. Information for defining control contents in power generation device control processing, charge / discharge control processing, and load device control processing to be executed in cycle T which will be performed next by executing prediction processing, load power prediction processing and power comparison processing Information as to whether or not this cycle T is included in the solar radiation period, together with the planned charging power Wcp at the coming cycle T, the predicted generated power Wgf at this cycle T, and the predicted load power Wlf at this cycle T Information indicating the comparison result of the generated power Wgf and the total power Wsm, and information indicating the comparison result of the sum of the predicted load power Wlf and the predicted generated power Wgf) is acquired.

The power generation device 3a is operated only for a fixed period and stopped. In this case, the power management device 9 detects the stop of the power generation device 3a, and shifts to the operation based on the power generated by the power generation device 3b.

In each cycle T when the power generation apparatus 3a is not operating, the power management apparatus 9 performs the second acquisition process, the third acquisition process, the charge power calculation process, the generated power prediction process, and the load power prediction performed in the immediately preceding cycle T. Information obtained by execution of processing and power comparison processing (planned charging power Wcp in the current cycle T, predicted generated power Wgf of the power generation device 3b in this cycle T, and predicted load power Wlf in this cycle T Information on whether the cycle T is included in the solar radiation period, information indicating the comparison result of the predicted generated power Wgf and the total power Wsm, and the comparison result of the sum of the predicted load power Wlf and the predicted generated power Wgf While defining control content in the power generation device control processing, charge / discharge control processing and load device control processing based on the information shown), the power generation device control with this prescribed control content Management, performing the charge and discharge control processing and load device control.

Next, a specific example is given and demonstrated. Planned charging power Wcp (total of) every day (every hour in this example) in the daytime (sunshine hour) and the period (nighttime) before and after that in one day, predicted generated power Wgf and predicted load power Wlf For example, it is assumed that (sum of) is calculated and estimated by the power management apparatus 9 as shown in FIG. In this case, regarding the relationship between the predicted generated power Wgf and the total power Wsm (= the predicted load power Wlf + the scheduled charging power Wcp in each storage battery 11), the power management apparatus 9 may The predicted generated power Wgf becomes less than the total power Wsm at 16 o'clock and 17 o'clock, and the predicted generated power Wgf coincides with the total power Wsm at 9 o'clock and the predicted generated power at 10 o'clock to 15 o'clock When Wgf exceeds the total power Wsm, prediction is made in a time (period T) immediately before each time (period T). Further, regarding the relationship between the predicted generated power Wgf and the predicted load power Wlf, the power management apparatus 9 makes the predicted generated power Wgf equal to or less than the predicted load power Wlf at night, for example, at 7 o'clock and 17 o'clock (for example, 7) On a hourly basis, if the predicted generated power Wgf exceeds the predicted load power Wlf from 8:00 to 16:00, the predicted generated power Wgf matches the predicted load power Wlf), and the prediction is made in the cycle T immediately before each cycle T Do.

Therefore, the power management apparatus 9 predicts the estimated generated power Wgf to be less than the total electric power Wsm and predicts the estimated generated power Wgf at the 7 o'clock and 17 o'clock stages at the 6 o'clock and 16 o'clock stages. It is predicted that the load power Wlf will be less than or equal to (the predicted generated power Wgf coincides with the predicted load power Wlf for 7 o'clock), and based on the predicted information, the fourth mentioned above for this 7 o'clock and 17 o'clock The charge / discharge control process, the load device control process, and the power generation device control process according to the process content are executed.

That is, as shown in FIG. 4, the power management apparatus 9 does not reduce the generated power Wgbp of the power generation device 3b with respect to the power conditioner 4b corresponding to the power generation device 3b in the power generation device control process. Control is performed to generate Wgf as it is (to generate the same actual generated power as the predicted generated power Wgf (hereinafter, also referred to as actual generated power Wgf)), and in the load device control process, to each DC / DC converter 5a, 5b On the other hand, while the bus voltage Vbs is converted and output so as to be the load voltages VLa and VLb used by the corresponding load devices 71a and 71b, the predicted load powers Wlfa and Wlfb are supplied as they are to the load devices 71a and 71b. (The same actual load power as the predicted load power Wlfa, Wlfb (hereinafter also referred to as actual load power Wlfa, Wlfb) Make) to run the control.

Further, in the charge and discharge control process, the power management device 9 equally divides the insufficient power (= predicted load power Wlf−predicted generated power Wgf) generated in the predicted generated power Wgf into each storage battery 11 and discharges it. At around 7 o'clock, since the predicted load power Wlf matches the predicted generated power Wgf and the above-mentioned insufficient power is zero, the discharge amount is zero. In the charge / discharge control process, the power management apparatus 9 determines the charge voltage Vba of each storage battery 11 included in the battery information acquired from the BMU 12 of each DC power supply 6 in the third acquisition process (for each storage battery 11 included in the battery information While specifying the DC power supply device 6 having the rechargeable storage battery 11 (the storage battery 11 in which the charging voltage Vba has not reached the lower limit value of the working voltage range) based on the SOC, The contact control information indicating the connection instruction is output to the BMU 12 and the control information indicating the discharge instruction is output to the bidirectional DC / DC converter 14 of the DC power supply device 6 (discharge operation is performed).

Further, in the power management apparatus 9, for example, at the 7 o'clock and 15 o'clock stages, the predicted generated power Wgf becomes less than the total electric power Wsm and the predicted generated power Wgf is about the 8 o'clock and 16 o'clock coming next. It is predicted that the predicted load power Wlf will be exceeded, and based on this predicted information, charge / discharge control processing, load device control processing, and power generation device control processing with the above-mentioned third processing contents are executed at this 8 o'clock and 16 o'clock. Do.

That is, as shown in FIG. 4, the power management apparatus 9 does not reduce the generated power Wgbp of the power generation device 3b with respect to the power conditioner 4b corresponding to the power generation device 3b in the power generation device control process. The control to generate Wgf as it is (generate the actual generated power Wgf) is executed, and in the load device control process, the load used by the corresponding load devices 71a and 71b for each DC / DC converter 5a and 5b Control is performed to supply the predicted load powers Wlfa and Wlfb to the load devices 71a and 71b as they are (to supply the actual load powers Wlfa and Wlfb) while converting and outputting the bus voltage Vbs to the voltages VLa and VLb. Do.

In addition, although the power management device 9 is smaller than the planned charging power Wcp in the charge and discharge control processing, the power obtained by evenly dividing the differential power (= the predicted generated power Wgf-the predicted load power Wlf) into each storage battery 11 Charge it. In this charge / discharge control process, the power management device 9 outputs contact control information indicating a connection instruction to the BMU 12 of the DC power supply 6 identified as having the rechargeable storage battery 11, and the DC power supply 6. By outputting control information indicating a charging instruction to the bidirectional DC / DC converter 14, the storage battery 11 of the DC power supply device 6 is charged (a charging operation is performed).

Further, for example, at 8 o'clock, the power management apparatus 9 predicts that the predicted generated power Wgf matches the total power Wsm at the next 9 o'clock, and based on the predicted information, the 9 o'clock In the above, the charge / discharge control process, the load device control process, and the power generation apparatus control process in the second process content described above are executed.

That is, as shown in FIG. 4, the power management apparatus 9 does not reduce the generated power Wgbp of the power generation device 3b with respect to the power conditioner 4b corresponding to the power generation device 3b in the power generation device control process. The control to generate Wgf as it is (generate the actual generated power Wgf) is executed, and in the load device control process, the load used by the corresponding load devices 71a and 71b for each DC / DC converter 5a and 5b Control is performed to supply the predicted load powers Wlfa and Wlfb to the load devices 71a and 71b as they are (to supply the actual load powers Wlfa and Wlfb) while converting and outputting the bus voltage Vbs to the voltages VLa and VLb. Do.

Further, in charge / discharge control processing, power management device 9 executes control similar to that in the charge / discharge control processing in the above-described third processing content to DC power supply 6, and charges planned charge power Wcp as it is. (The same actual charging power as the scheduled charging power Wcp (hereinafter, also referred to as the actual charging power Wcp) is charged).

Also, for example, in the 9 o'clock to 14 o'clock range, the power management apparatus 9 predicts that the predicted generated power Wgf will be larger than the total power Wsm in the next 10 o'clock to 15 o'clock range. Based on the predicted information, the charge / discharge control process, the load device control process, and the power generation apparatus control process in the first process described above are executed in the 10 to 15 o'clock range.

That is, as shown in FIG. 4, in the load device control process, power management device 9 applies load voltages VLa and VLb used by corresponding load devices 71a and 71b to DC / DC converters 5a and 5b. Control to cause the load devices 71a and 71b to supply the predicted load powers Wlfa and Wlfb as they are (by supplying the actual load powers Wlfa and Wlfb) to convert the bus voltage Vbs so that In the control process, the same control as in the charge / discharge control process in the third process content described above is performed on DC power supply device 6 to charge planned charge power Wcp as it is (charge actual charge power Wcp) .

Further, the power management device 9 predicts the generated power Wgbp of the power generation device 3b in the power generation device control process, as indicated by a white arrow in FIG. 4 with respect to the power conditioner 4b corresponding to the power generation device 3b. Control is performed to reduce the generated power Wgf by the difference power (= predicted generated power Wgf−total power Wsm) to the same power as the total power Wsm (= measured load power Wlf + scheduled charging power Wcp). Thereby, in the charge and discharge control process as described above, it is possible to charge each storage battery 11 with the actual charging power Wcp having the same power value as the planned charging power Wcp. Therefore, the charging current of each storage battery 11 can be suppressed to less than the maximum current value.

As described above, the power management apparatus 9 supplies each storage battery 11 with the same actual charging power Wcp as the corresponding planned charging power Wcp in a period in which the predicted generated power Wgf in the solar radiation period becomes larger than the total power Wsm. As described above, by reducing the generated power Wgbp of the power generation device 3b, it is possible to increase the possibility that the current value of the charging current to each storage battery 11 can be made lower than the maximum current value as much as possible. Each storage battery 11 is shifted to a substantially fully charged state using the entire area.

Further, the power management apparatus 9 executes the second acquisition process, the third acquisition process, the charge power calculation process, the generated power prediction process, the load power prediction process, and the power comparison process described above at each time (period T). Information for defining control contents in charge / discharge control processing and load device control processing to be executed in next coming cycle T (planned charging power Wcp in coming cycle T, predicted generated power Wgf in this cycle T Together with predicted load power Wlf at this cycle T, information on whether or not this cycle T is included in the solar radiation period, information indicating the comparison result of predicted generated power Wgf and total power Wsm, and predicted load power Wlf Information indicating the comparison result of the sum of the above and the predicted generated power Wgf).

As described above, in the DC power feeding system 1, the power management apparatus 9 predicts the result of the comparison in the power comparison process executed before the next cycle T (in the cycle T immediately before this cycle T). If the result is that the generated power Wgf is larger than the total power Wsm (= the sum of the predicted load powers Wlfa and Wlfb + the total of the scheduled charging power Wcp in each storage battery 11) (the predicted generated power Wgf is larger than the total power Wsm When it is determined that the control content in the power generation device control processing, the charge and discharge control processing, and the load device control processing is defined as the first control content described above in the next cycle T, it is executed. Specifically, in the next cycle T, power management device 9 supplies power to bi-directional DC / DC converter 14 from direct current bus 2 to corresponding storage battery 11 for the same actual charging power Wcp as planned charging power Wcp. The charge / discharge control process of charging the storage battery 11 by supplying it is executed, and the same actual load power Wlfa, Wlfb as the predicted load power Wlfa, Wlfb is applied to the corresponding load devices 71a, 71b for each DC / DC converter 5a, 5b. The load device control process for supplying the power is performed, and the generated power Wgbp of the power generation device 3b is calculated from the predicted generated power Wgf to the power difference 4 (= predicted generated power Wgf-total) for the power conditioner 4b corresponding to the power generation device 3b. Control is performed to reduce (decrease) the power by the power Wsm, that is, to make the same power as the total power Wsm.

Therefore, according to this DC feeding system 1, when it is predicted that the predicted generated power Wgf in the next coming cycle T will be larger than the total power Wsm, in this cycle T, the generated power Wgbp of the power generation device 3b is Since it is controlled to the same power as the total power Wsm smaller than the predicted generated power Wgf, the actual charging power Wcp supplied to each storage battery 11 can be suppressed to the same as the scheduled charging power Wcp. It is possible to prevent the power consumption from becoming too large (that is, the charging current to become a large current value at or near the maximum current value), thereby avoiding the occurrence of a situation where the deterioration of the storage battery 11 is accelerated. Thereby, deterioration of the storage battery 11 can be delayed.

Note that the DC power feeding system 1 is not limited to the above configuration. For example, although the acquisition time for acquiring the weather prediction information Dwf and the like is configured to arrive at a constant period T, the present invention is not limited to this configuration, and a configuration that arrives at different time intervals (for example, natural reproduction It may be configured to arrive at a short time interval in a time zone in which the power generation device 3b using energy operates, and to arrive at a longer time interval in a time zone in which the power generation device 3b stops operation.

Further, the DC power supply system 1 described above operates on the basis of the charging power of the storage battery 11 _1, BMU12, contactors 13, and a configuration including the DC / DC converter 7 supplies an operating voltage Vop to the power management apparatus 9 Although employed, it is not limited to this. For example, the bus voltage Vbs of the DC bus 2 is sufficiently set within a predetermined voltage range (voltage range of 350 V or more and 400 V or less of DC) by the DC power supply 6 after the power generation device 3b stops power generation and resumes power generation. BMU 12 and contactor 13 are configured such that the capacity of each storage battery 11 is sufficiently large and charging voltage Vba does not fall below the lower limit of the working voltage range. The power management device 9 operates with the charging voltage Vba of at least one of the storage batteries 11 and operates the charging voltage Vba of the corresponding storage battery 11. It can be omitted.

According to the present invention, it is possible to avoid a situation in which the storage battery charged with the power generated from the natural energy power generation device accelerates deterioration, so the present invention is widely applied to a stand-alone DC feeding system having a natural energy power generation device and a storage battery. It can apply.

DESCRIPTION OF SYMBOLS 1 DC electric power feeding system 2 DC bus 3 Electric power generation apparatus 4 1st converter 5 2nd converter 8 Temperature measurement part 9 Power management apparatus 11 Storage battery 14 Bidirectional DC / DC converter 71 Load apparatus Drg1 Power generation log Drg2 Load log Dwf Weather forecast information VLa, VLb load voltage

Claims (1)

A DC bus which is a bus bar of DC power supply,
A generator that generates electricity based on natural energy,
A first converter for supplying power generated by the power generation device to the DC bus;
A storage battery,
Connected between the storage battery and the DC bus, the generated power supplied to the DC bus and the charging power of the storage battery are bi-directionally converted to power from the DC bus to the storage battery, or A bi-directional converter that supplies power from the storage battery to the DC bus;
A second converter for converting the DC power of at least one of the generated power and the charging power supplied to the DC bus, and supplying the converted power to a load device;
A power generation log including weather conditions and generated power when the power generating apparatus operates, and a load log including weather conditions and load power when the load device operates, and chargeable power and weather prediction of the storage battery And a control unit that sequentially acquires information at a predetermined acquisition time,
The control unit calculates, on the basis of the chargeable power and the weather prediction information, the scheduled charging power for the storage battery in the period up to the acquisition time that arrives next, each time the chargeable power and the weather prediction information are acquired. Charge power calculation processing, power generation prediction processing for calculating predicted power generation of the power generation apparatus in the period based on the power generation log and the weather prediction information, predicted load power of the load device in the period during the load Load power prediction processing calculated based on a log and the weather prediction information, and power comparison processing for comparing the total power of the predicted load power and the planned charging power with the predicted generated power
Charge / discharge control processing for supplying the planned charging power to the storage battery with respect to the bi-directional converter during the period when it is determined in the power comparison processing that the predicted generated power is larger than the total power; Load device control processing for supplying the predicted load power to the load device with respect to the second converter, and reducing the difference between the predicted generated power and the total power of the generated power to the power generation device DC power supply system that performs power generation device control processing.

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