JP2015116098A - Capacitor output control device and output control method - Google Patents

Abstract

To provide an output control device for a capacitor capable of suppressing the progress of deterioration of the capacitor due to discharge exceeding the limit power of the capacitor. An output control device for an electric storage device in a vehicle including an electric motor driven by a chargeable / dischargeable electric storage as a power source includes a target power deriving unit for deriving a target power output from the electric motor in accordance with a required driving force for the vehicle. A discharge power deriving unit for deriving the discharge power of the battery according to the target power, and a use area setting unit for setting the SOC use area of the battery according to the discharge power of the battery derived by the discharge power deriving unit. [Selection] Figure 4

Description

  The present invention relates to an output control device and an output control method for a capacitor in a vehicle including an electric motor that drives a chargeable / dischargeable capacitor as a power source.

  Vehicles such as HEVs (Hybrid Electrical Vehicles) and EVs (Electrical Vehicles) are equipped with electric motors and travel by the driving force of the electric motors according to the driving state of the vehicle and the accelerator operation of the driver. The electric motor is driven by electric power supplied from the battery. Further, when the vehicle decelerates, the electric motor operates as a generator, and the electric power generated by the regenerative energy is charged in the capacitor. The power storage device is provided with a plurality of power storage cells connected in series. Secondary batteries, such as a nickel metal hydride battery and a lithium ion battery, are used for an electrical storage cell. In order to utilize the deterioration of the secondary battery to the minimum, it is necessary to perform control for preventing overcharge and overdischarge of the battery. Therefore, as shown in FIG. 8, the limit powers on the discharge side and the charge side are set in the battery. Each power limit varies depending on the remaining capacity (SOC: State of Charge) of the battery. FIG. 8 shows a case in which the allowable power range indicating the range from the discharge-side limit power to the charge-side limit power is wider as the SOC is higher.

JP 2010-088167 A

  Since the allowable power range is narrow when the SOC of the capacitor described above is low, as shown by a one-dot chain line in FIG. 9, the capacitor has a power exceeding the limit power on the discharge side according to the driving state of the vehicle or the accelerator operation of the driver. It may be supplied to the electric motor. However, the discharge of power exceeding the limit power causes deterioration of the battery. For this reason, the progress of the deterioration of the battery is suppressed by shifting the SOC of the battery to a higher level. However, since the output of the capacitor decreases at a low temperature, there is a higher possibility that a discharge exceeding the limit power of the capacitor will be performed even if the SOC is high compared to that at room temperature. However, if the capacity of the battery is increased so as not to exceed the limit power on the discharge side even at low temperatures, it will hinder the miniaturization or weight reduction of the system.

  An object of the present invention is to provide an output control device and an output control method for a capacitor that can suppress the progress of deterioration of the capacitor due to discharge exceeding the limit power of the capacitor.

  In order to solve the above-described problems and achieve the object, an output control device for a capacitor according to claim 1 drives a chargeable / dischargeable capacitor (for example, capacitor 101 in the embodiment) as a power source. An output control device for the electric storage device in a vehicle including an electric motor (for example, the electric motor 109 in the embodiment), which derives a target power derived from the target power output by the electric motor according to a required driving force for the vehicle. A unit (for example, target power calculation unit 153 in the embodiment), and a discharge power deriving unit (for example, discharge power calculation unit 155 in the embodiment) for deriving the discharge power of the battery according to the target power. The use area setting unit that sets the SOC use area of the battery according to the discharge power of the battery derived by the discharge power deriving part (for example, the use area setting unit 15 in the embodiment) ) And it is characterized by having a.

  Furthermore, in the output control apparatus for a battery according to the invention of claim 2, if the SOC utilization region is within an allowable power range from a discharge-side limit power preset to the capacitor to a charge-side limit power. It is a utilization area on the capacity of the battery that does not restrict charging / discharging of the battery.

  Furthermore, in the output control device for a battery according to the invention of claim 3, the use area setting unit is configured such that the discharge power of the battery derived by the discharge power deriving part is a discharge-side limit preset in the battery. Count the number of times the power is exceeded, and if the number reaches the threshold value, the maximum discharge power value within the discharge power value exceeding the limit power on the discharge side falls within the allowable power range of the battery. The SOC use area is set as described above.

  Furthermore, in the output control device for a battery according to the invention of claim 4, the use area setting unit is configured such that the discharge power of the battery derived by the discharge power deriving unit is a limit on a discharge side set in advance in the battery. Counting the number of times the power has been exceeded, and if the number of times reaches a threshold value, the SOC utilization region so that the average value of the discharge power value exceeding the limit power on the discharge side is within the allowable power range of the battery It is characterized by setting.

  Furthermore, in the output control device for a battery according to the invention of claim 5, the use area setting unit is configured to set a discharge-side limit, in which the discharge power of the battery derived by the discharge power deriving unit is preset in the battery. Count the number of times the power is exceeded, and if the number reaches the threshold, the mode value in the approximate value of the discharge power value exceeding the limit power on the discharge side is within the allowable power range of the battery. The SOC use area is set.

  Furthermore, in the output control device for a battery according to the invention of claim 6, the use area setting unit is configured such that the discharge power of the battery derived by the discharge power deriving part is a discharge-side limit preset in the battery. If the number of times that the power is exceeded is counted and the number of times reaches a threshold value, the average value of the discharge power value of the capacitor derived by the discharge power deriving unit is the center on the discharge side in the allowable power range of the capacitor. The SOC use area is set so as to coincide with the value.

  Furthermore, in the output control device for a battery according to the invention of claim 7, when the remaining capacity of the battery is lower than the lower limit value of the SOC use area set by the use area setting unit, the discharge from the battery is suppressed. It is characterized by doing.

  Furthermore, in the output control method for a capacitor according to an eighth aspect of the present invention, an electric motor (for example, the electric motor 109 in the embodiment) that is driven by using a chargeable / dischargeable electric capacitor (for example, the electric capacitor 101 in the embodiment) as a power source. An output control method for the battery in a vehicle comprising: a target power deriving step for deriving a target power output from the electric motor according to a required driving force for the vehicle; and a method for controlling the battery according to the target power. A discharge power deriving step for deriving discharge power, and a use area setting step for setting an SOC use area of the battery according to the discharge power of the battery derived in the discharge power deriving step. Yes.

  According to the output control device for a capacitor according to any one of claims 1 to 7 and the output control method for a capacitor according to claim 8, it is possible to suppress the progress of deterioration of the capacitor due to discharge exceeding the limit power of the capacitor. .

Block diagram showing the internal configuration of a series-type HEV The block diagram which shows the internal structure of management ECU123 The figure which shows the relationship of two types of SOC utilization area | regions in the electrical storage device 101. The figure which shows the limit value on discharge control and the limit value on charge control set with respect to each SOC utilization area | region The figure which shows an example of the change of the charging / discharging electric power of the electrical storage device 101 which the discharge electric power calculation part 155 of management ECU123 calculated according to driving | running | working of a vehicle. Flow chart showing the operation of the management ECU 123 The figure which shows an example of the change of charging / discharging electric power according to driving | running | working of the vehicle with respect to the allowable electric power range of the electrical storage device 101. The figure which shows each limit electric power of the discharge side and charge side according to SOC of a capacitor | condenser The figure which shows an example of the change of charging / discharging electric power according to driving | running | working of the vehicle with respect to the allowable electric power range of an electrical storage device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the internal configuration of a series-type HEV. 1 includes a battery (BATT) 101, a temperature sensor (TEMP) 103, a converter (CONV) 105, a first inverter (first INV) 107, and an electric motor. (MOT) 109, internal combustion engine (ENG) 111, generator (GEN) 113, second inverter (second INV) 115, gear box (hereinafter simply referred to as “gear”) 119, and vehicle speed sensor 121. A management ECU (FI / MG ECU) 123, a motor ECU (MOT / GEN ECU) 125, and a battery ECU (BATT ECU) 127. In addition, the solid line arrow in FIG. 1 indicates value data, and the alternate long and short dash line arrow indicates a control signal including instruction contents.

  The storage battery 101 has a plurality of storage cells connected in series, and supplies a high voltage of, for example, 100 to 200V. The storage cell is a secondary battery such as a nickel metal hydride battery or a lithium ion battery. Charging / discharging of the battery 101 is repeated within the range of the control SOC in which the battery 101 can be used (lower limit SOC to upper limit SOC). The temperature sensor 103 detects the temperature of the battery 101 (hereinafter referred to as “battery temperature”). A signal indicating the battery temperature detected by the temperature sensor 103 is sent to the battery ECU 127.

  Converter 105 boosts or lowers the DC output voltage of battery 101 while maintaining the direct current. The first inverter 107 converts a DC voltage into an AC voltage and supplies a three-phase current to the electric motor 109. Further, the first inverter 107 converts the AC voltage input during the regenerative operation of the electric motor 109 into a DC voltage and charges the battery 101.

  The electric motor 109 generates power for the vehicle to travel. Torque generated by the electric motor 109 is transmitted to the drive shaft 131 via the gear 119. Note that the rotor of the electric motor 109 is directly connected to the gear 119. In addition, the electric motor 109 operates as a generator during regenerative braking, and the electric power generated by the electric motor 109 is charged in the battery 101.

  The internal combustion engine 111 is a power source when the generator 113 generates power. The internal combustion engine 111 is directly connected to the rotor of the generator 113.

  The generator 113 generates electric power using the power of the internal combustion engine 111. The electric power generated by the generator 113 is charged in the battery 101 or supplied to the electric motor 109. The second inverter 115 converts the AC voltage generated by the generator 113 into a DC voltage. The electric power converted by the second inverter 115 is charged in the battery 101 or supplied to the electric motor 109 via the first inverter 107.

  The gear 119 is a one-stage fixed gear corresponding to, for example, the fifth speed. The vehicle speed sensor 121 detects the traveling speed (vehicle speed VP) of the vehicle. A signal indicating the vehicle speed VP detected by the vehicle speed sensor 121 is sent to the management ECU 123.

  The management ECU 123 calculates the required driving force based on the accelerator pedal opening (AP opening) and the vehicle speed VP according to the accelerator operation of the driver of the vehicle, calculates the power output from the electric motor 109 according to the required driving force, and the battery 101 performs input / output control and the like. Details of the management ECU 123 will be described later.

  The motor ECU 125 controls the operation of the electric motor 109 or the generator 113 by switching control of the switching elements constituting the converter 105, the first inverter 107, and the second inverter 115, respectively. In FIG. 1, control of converter 105, first inverter 107, and second inverter 115 by motor ECU 125 is indicated by a one-dot chain line.

  The battery ECU 127 derives the SOC and the like of the battery 101 based on information such as the battery temperature obtained from the temperature sensor 103 and the charge / discharge current and terminal voltage of the battery 101.

  FIG. 2 is a block diagram showing the internal configuration of the management ECU 123. As shown in FIG. 2, the management ECU 123 includes a required driving force calculation unit 151, a target power calculation unit 153, a discharge power calculation unit 155, and a use area setting unit 157.

  The required driving force calculation unit 151 calculates the required driving force based on the AP opening degree and the vehicle speed VP. The target power calculation unit 153 calculates the target power output from the electric motor 109 according to the required driving force. Discharge power calculation unit 155 calculates the discharge power of battery 101 according to the target power of electric motor 109.

  The use area setting unit 157 sets the storage device 101 in advance within the range of the control SOC in which the storage device 101 can be used (lower limit SOC to upper limit SOC) according to the discharge power of the storage device 101 calculated by the discharge power calculation unit 155. If it is within the allowable power range from the discharge-side limit power to the charge-side limit power, an SOC utilization region that does not restrict charging / discharging of the battery 101 is set. FIG. 3 is a diagram illustrating a relationship between two different SOC usage areas in the battery 101. In the example shown in FIG. 3, when the SOC use area A is set, the control SOC of the battery 101 is limited to Cla to Cb (%). Therefore, the minimum allowable power range when the SOC use area A is set is the allowable power range A when the control SOC is Cla (%). On the other hand, when the SOC use area B is set, the control SOC of the battery 101 is limited to Clb to Cb (%). Therefore, the minimum allowable power range when the SOC utilization area B is set is the allowable power range B when the control SOC is Clb (%). The lower limit value Clb of the SOC usage area B is higher than the lower limit value Cla of the SOC usage area A, and the upper limit value Cb is common to the two SOC usage areas A and B.

  The power supply from the battery 101 to the electric motor 109 is controlled so that the control SOC of the battery 101 is within the SOC usage area set by the usage area setting unit 157. That is, when the control SOC of the battery 101 falls below the lower limit value of the SOC use area based on the SOC use area set by the use area setting unit 157 of the management ECU 123, the motor ECU 125 discharges the battery 101. Control to suppress.

  FIG. 4 is a diagram showing discharge control limit values and charge control limit values set for the SOC utilization regions A and B shown in FIG. 3. As shown in FIG. 4, when the SOC utilization area A is set, the motor ECU 125 has a limit power on the discharge side of the battery 101 as long as the control SOC is Cla (%) or more, as indicated by a one-dot chain line. However, if the control SOC is less than Cla (%), the battery 101 is controlled not to discharge. On the other hand, as shown by the two-dot chain line, the motor ECU 125 when the SOC usage area B is set is similar to the SOC usage area A as long as the control SOC is Clb (%) or more. The discharge control is performed so as not to exceed the limit power on the discharge side of the battery. However, if the control SOC falls below Clb (%), the battery 101 is controlled not to discharge.

  As shown by the solid line in FIG. 4, the charging control of the battery 101 by the motor ECU 125 is performed on the charging side of the battery 101 as long as the control SOC is equal to or less than Ch (%) regardless of the set SOC usage region. This is done so as not to exceed the limit power.

  Hereinafter, an example of setting the SOC usage area by the usage area setting unit 157 will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of a change in the charge / discharge power of the battery 101 calculated by the discharge power calculation unit 155 of the management ECU 123 according to the traveling of the vehicle. The use area setting unit 157 counts the number of times that the discharge power of the battery 101 calculated periodically by the discharge power calculation unit 155 exceeds the limit power on the discharge side corresponding to the control SOC at the time of the calculation. Furthermore, when the number of times reaches a threshold value (for example, 3 times), the usage area setting unit 157 sets the SOC usage area based on one of the following three methods.

(First setting method)
In the first setting method, the use area setting unit 157 has a maximum discharge power value (for example, the time shown in FIG. 5) among the discharge power values exceeding the limit power on the discharge side calculated by the discharge power calculation unit 155. The SOC utilization region is set with the control SOC within which the discharge power value Pomax of tb is within the allowable power range of the battery 101 shown in FIG.

(Second setting method)
In the second setting method, the use area setting unit 157 has a discharge power value exceeding the limit power on the discharge side calculated by the discharge power calculation unit 155 (for example, each discharge power value at times ta to tf shown in FIG. 5). ) Is set as the lower limit value of the control SOC within the allowable power range of the battery 101.

(Third setting method)
In the third setting method, the use area setting unit 157 has a discharge power value exceeding the limit power on the discharge side calculated by the discharge power calculation unit 155 (for example, each discharge power value at times ta to tf shown in FIG. 5). ), The SOC usage region is set with the control SOC at which the mode value in the approximate value falls within the allowable power range of the battery 101 as the lower limit.

(Fourth setting method)
In the fourth setting method, the use area setting unit 157 determines that the average value of the discharge power value calculated by the discharge power calculation unit 155 in the most recent time zone coincides with the median value on the discharge side in the allowable power range of the battery 101. The SOC usage area to be set is set.

  FIG. 6 is a flowchart showing the operation of the management ECU 123. As shown in FIG. 7, the discharge power calculation unit 155 of the management ECU 123 calculates the discharge power of the battery 101 according to the target power of the electric motor 109 calculated by the target power calculation unit 153 (step S101). Next, the use area setting unit 157 of the management ECU 123 determines whether or not the discharge power calculated in step S101 exceeds the limit power on the discharge side according to the control SOC at that time (step S103). The process proceeds to step S105, and if not exceeded, the process returns to step S101. In step S105, the use area setting unit 157 increments the number n of times that the discharge power calculated in step S101 exceeds the limit power on the discharge side by one.

  Next, in step S107, the use area setting unit 157 determines whether or not the number n counted in step S105 has reached the threshold th (n ≧ th), and if n ≧ th, step S109. If n <th, the process returns to step S101. In step S109, the use area setting unit 157 sets the SOC use area based on one of the first to fourth setting methods described above according to the discharge power exceeding the limit power on the discharge side calculated in step S101. Set. Next, the use area setting unit 157 resets the number of times n to 0 (step S111), and returns to step S101.

  As described above, in the present embodiment, the SOC use area corresponding to the discharge power of the battery 101 calculated by the discharge power calculation unit 155 of the management ECU 123 is set, and the discharge control of the battery 101 is performed according to the set SOC use. This is done so as not to greatly fall below the lower limit of the area. Moreover, when the number of times that the discharge power of the battery 101 calculated by the discharge power calculation unit 155 exceeds the limit power on the discharge side reaches a predetermined number, the use area setting unit 157 of the management ECU 123 reaches the limit power on the discharge side. Is set in the SOC utilization region with the control SOC in which the maximum value, the average value, or the approximate mode value of the discharged power within the allowable power range of the battery 101 falls within the allowable power range. At this time, the control SOC of the battery 101 changes only within the set SOC use area, and the charge / discharge power of the battery 101 does not exceed the allowable power range in the control SOC within this SOC use area. As a result, as shown in FIG. 7, since the vehicle travels without the discharge power of the battery 101 corresponding to the target power of the electric motor 109 exceeding the limit power on the discharge side, the progress of deterioration of the battery 101 can be suppressed.

  In this embodiment, the series-type HEV has been described as an example. However, a parallel-type HEV, a series / parallel-type HEV in which the series method and the parallel method are combined, or an EV (Electrical Vehicle) is used. There may be. In the present embodiment, the SOC usage region is set so that the discharge power of the battery 101 does not exceed the discharge-side limit power, but the SOC use region is set so that the charge power to the capacitor 101 does not exceed the charge-side limit power. May be set.

101 Battery (BATT)
103 Temperature sensor (TEMP)
105 Converter (CONV)
107 1st inverter (1st INV)
109 Motor (MOT)
111 Internal combustion engine (ENG)
113 Generator (GEN)
115 2nd inverter (2nd INV)
119 Gearbox 121 Vehicle speed sensor 123 Management ECU (FI / MG ECU)
125 Motor ECU (MOT / GEN ECU)
127 Battery ECU (BATT ECU)
131 Drive shaft 133 Drive wheel 151 Required drive force calculation unit 153 Target power calculation unit 155 Discharge power calculation unit 157 Use area setting unit

Claims (8)

In a vehicle equipped with an electric motor that drives a chargeable / dischargeable capacitor as a power source, the output control device for the capacitor,
A target power deriving unit for deriving a target power output by the electric motor according to a required driving force for the vehicle;
A discharge power deriving unit for deriving the discharge power of the battery according to the target power;
A use area setting unit that sets a SOC use area of the battery according to the discharge power of the battery derived by the discharge power deriving part;
An output control device for a capacitor, comprising: An output control device for a battery according to claim 1,
The SOC utilization area is a utilization area on the capacity of the battery that does not limit charging / discharging of the battery as long as it is within an allowable power range from a discharge-side power limit to a charge-side power limit preset for the battery. An output control device for a capacitor, characterized in that An output control device for a battery according to claim 2,
The utilization area setting unit counts the number of times that the discharge power of the capacitor derived by the discharge power deriving unit exceeds the limit power on the discharge side preset in the capacitor, and the number of times reaches the threshold value. In this case, the SOC use region is set so that the maximum discharge power value within the discharge power value exceeding the limit power on the discharge side is within the allowable power range of the capacitor. apparatus. An output control device for a battery according to claim 2,
The utilization area setting unit counts the number of times that the discharge power of the capacitor derived by the discharge power deriving unit exceeds the limit power on the discharge side preset in the capacitor, and the number of times reaches the threshold value. In this case, the SOC output region is set such that the average value of the discharge power value exceeding the limit power on the discharge side is within the allowable power range of the capacitor. An output control device for a battery according to claim 2,
The utilization area setting unit counts the number of times that the discharge power of the capacitor derived by the discharge power deriving unit exceeds the limit power on the discharge side preset in the capacitor, and the number of times reaches the threshold value. In this case, the SOC control region is set such that the mode value in the approximate value of the discharge power value exceeding the limit power on the discharge side is within the allowable power range of the capacitor. . An output control device for a battery according to claim 2,
The utilization area setting unit counts the number of times that the discharge power of the capacitor derived by the discharge power deriving unit exceeds the limit power on the discharge side preset in the capacitor, and the number of times reaches the threshold value. Then, the SOC utilization region is set so that the average value of the discharge power value of the battery derived by the discharge power deriving unit matches the median value on the discharge side in the allowable power range of the battery. An output control device for a battery. It is an output control device of the accumulator according to any one of claims 1 to 6,
An output control device for a battery, wherein when the remaining capacity of the battery is below a lower limit value of the SOC use area set by the use area setting unit, discharge from the battery is suppressed. In a vehicle equipped with an electric motor that drives a chargeable / dischargeable capacitor as a power source, the output control method for the capacitor,
A target power deriving step for deriving a target power output by the electric motor in accordance with a required driving force for the vehicle;
A discharge power deriving step for deriving the discharge power of the battery according to the target power;
A use area setting step of setting a SOC use area of the battery according to the discharge power of the battery derived in the discharge power deriving step;
A method of controlling the output of a battery, comprising:

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