JP2013221759A - Electricity meter - Google Patents

Abstract

An object of the present invention is to prevent an error in calculation of commercial power charges due to a self-sustaining operation in which power is exchanged between a plurality of consumers.
A watt-hour meter provided in a self-sustained operation system accumulates and holds the amount of power flowing through a service line of a distribution system, and whether or not to accumulate the amount of power in the storage unit. And a weighing switching unit 305 for switching between. The signal input unit 306 determines whether or not the autonomous operation using the lead-in line 104 is being performed based on the independent operation notification signal from the outside, and while the autonomous operation is being performed, the storage unit 303 determines the amount of power. The measurement switching unit 305 is controlled so as not to accumulate.
[Selection] Figure 2

Description

  The present invention relates to a watt-hour meter that measures the amount of power flowing through a power distribution system of an electric power company, and more particularly to a self-sustaining operation system that performs a self-sustained operation using the power distribution system.

  In recent years, power supply facilities such as a household solar power generation system (PV) and a storage battery (SB) have been widely used. Consumers who own solar power generation systems and storage batteries can continue to use electricity by self-sustaining operation using these power supply facilities, even in the event of a power outage that cuts off the power supply from the electric power company (electric power company). Can be used.

  In addition, when a certain area to which multiple customers belong, such as a power outage due to a disaster, if a power distribution facility (distribution system) of an electric power company can be borrowed, a plurality of nearby consumers can operate the power facility and It is possible to operate autonomously on a regional basis by passing electricity between consumers through the network. If this can be realized, it will be possible to continue using electricity throughout the region even during a power outage.

  Patent Document 1 below discloses a watt-hour meter that measures power separately for each time zone. With this watt-hour meter, the power used can be measured separately for each predetermined time period.

JP 59-180368 A

  When multiple customers exchange power through the power distribution system and carry out independent operation, a watt-hour meter for commercial transactions installed at each customer (used to calculate electricity charges based on supply-demand contracts with power companies) Power meter) also works. For this reason, the electric power supplied from the power supply facilities of other consumers is also measured by the watt-hour meter for commercial transactions, and an error occurs in the calculation of the electricity bill.

  The present invention has been made to solve the above-described problems, and prevents an error from occurring in the calculation of commercial power charges even when a self-sustained operation in which power is exchanged among a plurality of consumers is performed. An object is to provide a watt-hour meter that can be used.

  The watt-hour meter according to the present invention includes a first storage unit capable of accumulating and holding the amount of power flowing through the distribution system, and a metering switching unit for switching whether or not the first storage unit accumulates the power amount. A determination unit that determines whether or not a self-sustained operation using the power distribution system is performed, and the determination unit accumulates the electric energy while the self-sustained operation is performed. The measurement switching unit is controlled so as not to occur.

  According to the watt-hour meter according to the present invention, the electric power supplied from other consumers via the distribution system during the self-sustained operation is not confused with and integrated with the commercial power. Independent operation using the power distribution system can be performed while preventing errors.

It is a block diagram which shows the structure of the independent operation system which concerns on Embodiment 1. FIG. 1 is a block diagram showing a configuration of a watt-hour meter according to Embodiment 1. FIG. It is a block diagram which shows the structure of the independent operation system which concerns on Embodiment 2. FIG. 6 is a block diagram showing a configuration of a watt-hour meter according to Embodiment 2. FIG. 6 is a block diagram showing a configuration of a watt-hour meter according to Embodiment 3. FIG.

<Embodiment 1>
Hereinafter, an embodiment of a self-sustained operation system according to the present invention and a watt-hour meter deployed therein will be described. In the following explanation, among the power lines of the distribution system, the power lines that send electricity from the power station or substation (transformer) of the electric power company to each region are referred to as “distribution lines”, and the distribution lines pass through the distribution transformer. The power line for branching and drawing electricity to each consumer is referred to as a “lead line”. Moreover, although the power line in each consumer is called "indoor wiring" for convenience, the arrangement place may be inside or outside the building.

  FIG. 1 is a block diagram showing a configuration of a self-sustaining operation system according to Embodiment 1 of the present invention. A switch 102 is installed at a predetermined position on the distribution line 101 of this independent operation system. When the supply from the electric power company is stopped due to an accident or disaster, each switch 102 is opened. Independent operation is possible for each section surrounded by the plurality of switches 102 in the released state. A lead-in wire 104 for supplying power to a plurality of consumers 200 is connected to the distribution line 101 via a distribution transformer 103.

  In each customer 200, the lead-in wire 104 is connected to the indoor wiring 205 through a watt-hour meter (WHM) 300 according to the present invention that can support independent operation. Indoor wiring 205 extending from watt-hour meter 300 is connected to load facility 201 and inverter 202. The inverter 202 is in contact with power supply facilities such as a photovoltaic power generation system (PV) 203 and a storage battery (SB) 204, and has a function of converting the output power from direct current to alternating current. Further, the inverter 202 functions to control the voltage and frequency of the AC power to be output when the autonomous operation is performed.

  The inverter 202 and the watt hour meter 300 of each customer 200 are connected to an external autonomous operation control system 105 via the communication line 106. The self-sustained operation control system 105 starts and ends a self-sustained operation (a self-sustained operation in which a plurality of consumers 200 exchange power through the power distribution system (the service line 104)) with a plurality of consumers 200 connected to each other via the service line 104. A signal to be notified (hereinafter referred to as “independent operation notification signal”) is output to the communication line 106. Therefore, the inverter 202 and the watt-hour meter 300 of each customer 200 can determine whether or not the autonomous operation using the power distribution system is performed in the area based on the autonomous operation notification signal from the autonomous operation control system 105. .

  In the self-sustained operation system of FIG. 1, for example, when a power failure occurs due to an accident or disaster and the self-sustained operation using the power distribution system is performed, the switch 102 is first opened, and the self-sustained operation control system 105 is sent to each customer 200. Send a notice of start of autonomous operation. The inverter 202 of each consumer 200 adjusts the output power of the solar power generation system 203 and the power stored in the storage battery 204 to a predetermined voltage and frequency, and then outputs them to the indoor wiring 205. Thereby, each customer 200 can continue to supply electric power to the load facility 201 even during a power failure.

  In particular, in the self-sustained operation using the power distribution system, power can be exchanged between the consumers 200 through the power distribution system (the service line 104). In this case, for example, even if the electric power stored in the storage battery 204 of a certain consumer 200 becomes zero, the consumer 200 can receive power supply from other nearby consumers 200. Therefore, it can also contribute to strengthening regional disaster countermeasures.

  In addition, when a power failure becomes widespread and the independent operation is terminated, the switch 102 is closed and the autonomous operation control system 105 transmits an independent operation end notification to the customer 200. By closing the switch 102, each consumer 200 can receive power supply from an electric power company. Moreover, the inverter 202 of each customer 200 switches to the normal operation | movement which performs grid connection.

  FIG. 2 is a block diagram showing a configuration of watt-hour meter 300 according to Embodiment 1. The watt-hour meter 300 includes the following sensor unit 301, calculation unit 302, storage unit 303, output unit 304, metering switching unit 305, and signal input unit 306.

  The sensor unit 301 includes, for example, a transformer (PT) and a current transformer (CT). The sensor unit 301 reduces the voltage and current of power passing through the watt-hour meter 300 and converts them into values that can be processed by the calculation unit 302. . The voltage and current converted by the sensor unit 301 are input to the calculation unit 302.

  The arithmetic unit 302 includes, for example, a multiplication circuit and an integration circuit, and calculates the amount of power for each fixed period based on the voltage / current input from the sensor unit 301. The accumulating unit 303 (first accumulating unit) accumulates the amount of power calculated by the computing unit 302 and records the accumulated value in a nonvolatile memory (for example, a flash memory) and holds it. The output unit 304 outputs the accumulated amount of power recorded in the nonvolatile memory of the storage unit 303 to, for example, a liquid crystal display.

  The sensor unit 301, the calculation unit 302, the storage unit 303, and the output unit 304 may be the same as those in a general electronic watt-hour meter.

  In the watt-hour meter 300 according to the present embodiment, a metering switching unit 305 configured by a single pole single throw (SPST) type switch that switches between connection / release between the calculation unit 302 and the storage unit 303 is provided. Intervene. While the measurement switching unit 305 connects the calculation unit 302 and the storage unit 303, the power amount calculated by the calculation unit 302 is accumulated by the storage unit 303. However, since the amount of power calculated by the calculation unit 302 is not input to the storage unit 303 while the connection is released, the amount of power during that time is not accumulated. That is, the metering switching unit 305 functions to switch whether or not the storage unit 303 accumulates electric energy.

  The operation of the weighing switching unit 305 is controlled by a self-sustained operation notification signal from the self-sustained operation control system 105. That is, the watt-hour meter 300 includes a signal input unit 306 to which an independent operation notification signal is input, and the signal input unit 306 controls the metering switching unit 305 based on the independent operation notification signal.

  As described above, the self-sustained operation notification signal notifies the start / end of the self-sustained operation performed by exchanging power using the power distribution system (intake line 104). The signal input unit 306 functions as a determination unit that determines whether or not the independent operation is performed based on the independent operation notification signal and controls the measurement switching unit 305 according to the determination result. Specifically, when the signal input unit 306 receives the notice of the start of the independent operation, the signal input unit 306 controls the measurement switching unit 305 to disconnect from the accumulation unit 303 and the calculation unit 302. In addition, when receiving the notice of the end of the autonomous operation, the storage unit 303 is connected to the calculation unit 302.

  Accordingly, the watt-hour meter 300 of the present embodiment operates as a normal watt-hour meter when the self-sustained operation using the power distribution system is not performed, and is supplied from the electric power company and used by the consumer 200. The amount of power is accumulated in the storage unit 303. On the other hand, while the self-sustained operation is being carried out, even if electric power is used by the customer 200, the amount of electric power is not accumulated in the accumulating unit 303. Therefore, the watt-hour meter 300 can accumulate only the amount of power received and used from the power company and output the accumulated amount from the output unit 304. Since the accumulated amount of electric power does not include the amount of electric power used during independent operation, it is possible to prevent an error from occurring in the charge calculation based on the supply and demand contract with the electric power company.

<Embodiment 2>
The watt-hour meter 300 according to the first embodiment determines the start and end of the autonomous operation based on the autonomous operation notification signal from the autonomous operation control system 105. The total 300 is determined by itself.

  FIG. 3 is a block diagram illustrating a configuration of the self-sustained operation system according to the second embodiment. The configuration of the self-sustained operation system is almost the same as that of the first embodiment (FIG. 1), but a communication line 106 that transmits a self-sustained operation notification signal from the self-sustained operation control system 105 is connected to the watt-hour meter 300. Absent.

  Inverter 202 of the present embodiment has a function of changing the electrical characteristics of power (self-sustained operation power) that is output during the operation of self-sustained operation from that of commercial power supplied from an electric power company. Here, it is assumed that the inverter 202 sets the frequency of the power for autonomous operation to a value slightly different from the frequency of the commercial power. For example, if the frequency of commercial power is 50 Hz, the inverter 202 sets the frequency of power for autonomous operation to 51 Hz.

  FIG. 4 is a block diagram showing a configuration of the watt-hour meter 300 according to the second embodiment. The watt-hour meter 300 is provided with a self-sustaining operation detection unit 307 connected to the lead-in wire 104 in the configuration of the first embodiment (FIG. 2). Further, the signal input unit 306 receives an output signal of the independent operation detection unit 307.

  The autonomous operation detection unit 307 detects a difference in electrical characteristics between the commercial power and the autonomous operation power, and determines whether the electric power supplied to the watt-hour meter 300 is commercial electric power based on the detection result. It has a function of discriminating whether the electric power is used. In the present embodiment, the self-sustaining operation detection unit 307 is configured using, for example, a current transformer (PT) and a zero-cross detection circuit so that a change in frequency can be detected.

  The autonomous operation detection unit 307 detects that the frequency of power passing through the watt-hour meter 300 has changed from the frequency of commercial power (50 Hz in the above example) to the frequency of autonomous power (51 Hz in the above example). Then, a signal notifying the start of independent operation is input to the signal input unit 306. Conversely, when it is detected that the frequency of power passing through watt-hour meter 300 has changed from the frequency of power for autonomous operation to the frequency of commercial power, a signal for notifying the end of autonomous operation is input to signal input unit 306. .

  Similarly to the first embodiment, the signal input unit 306 controls the measurement switching unit 305 to be disconnected from the storage unit 303 and the calculation unit 302 when receiving the notification of the start of the independent operation. In addition, when receiving the notice of the end of the autonomous operation, the storage unit 303 is connected to the calculation unit 302.

  Therefore, the watt-hour meter 300 according to the second embodiment can accumulate only the amount of power received and used from the power company and output from the output unit 304, as in the first embodiment. Since the accumulated amount of electric power does not include the amount of electric power used during independent operation, it is possible to prevent an error from occurring in the charge calculation based on the supply and demand contract with the electric power company. In addition, the watt-hour meter 300 does not need to receive a self-sustained operation notification signal from the self-sustained operation control system 105, and a signal line therefor can be omitted, so that the configuration of the self-sustained operation system can be simplified.

  In the present embodiment, the electrical characteristic that is changed between the power for independent operation and the commercial power is the frequency, but other characteristics may be changed. For example, it is conceivable to change the voltage waveform between the electric power for independent operation and the commercial power. In that case, the inverter 202 superimposes a specific voltage waveform on the voltage waveform of the power for autonomous operation, and allows the independent operation detection unit 307 to detect the specific voltage waveform, thereby determining whether or not the autonomous operation is being performed. I can judge.

<Embodiment 3>
In Embodiments 1 and 2, since the power amount is not accumulated during the self-sustained operation using the distribution system, the power amount used by each customer 200 during that time cannot be measured. In the third embodiment, the watt-hour meter 300 is provided with means for accumulating and outputting (displaying) the amount of power used during the self-sustaining operation period.

  FIG. 5 is a block diagram showing a configuration of the watt-hour meter 300 according to the third embodiment. The watt-hour meter 300 is provided with a self-sustaining operation accumulation unit 309 and a self-sustaining operation output unit 310, and is a single pole single throw (SPST) type switch as compared with the configuration of the first embodiment (FIG. 2). Instead of the switching unit 305, a metering switching unit 308 which is a single pole double throw (SPDT) type switch is used.

  The independent operation accumulation unit 309 and the independent operation output unit 310 may basically have the same configuration as the accumulation unit 303 and the output unit 304. That is, the self-sustained operation storage unit 309 (second storage unit) can accumulate the electric energy calculated by the calculation unit 302 and store it in a nonvolatile memory (for example, a flash memory). The autonomous operation output unit 310 outputs, for example, a liquid crystal display or the like to the accumulated amount of electric power recorded in the nonvolatile memory of the autonomous operation storage unit 309.

  The operation of the weighing switching unit 308 is controlled by a signal input unit 306 that receives a self-sustained operation notification signal from the self-sustained operation control system 105. When the signal input unit 306 receives the start notification of the independent operation, the signal input unit 306 controls the measurement switching unit 308 to connect the storage unit 303 to the storage unit 309 for independent operation. In addition, when receiving the notice of the end of the autonomous operation, the storage unit 303 is connected to the calculation unit 302. That is, the metering switching unit 308 functions so that the metering switching unit 308 accumulates the electric energy instead, while the self-sustained operation is being performed and the accumulating unit 303 does not accumulate the electric energy.

  Therefore, in the watt-hour meter 300 according to the present embodiment, the amount of power used (the amount of commercial power used) when the autonomous operation using the distribution system is not implemented is accumulated by the accumulation unit 303, and the autonomous operation is implemented. The amount of electric power used (the amount of electric power used for autonomous operation) is accumulated by the accumulation unit 309 for autonomous operation. Therefore, the watt-hour meter 300 can measure and output (display) the usage amount of the power for independent operation separately from the usage amount of the commercial power.

  5 shows a configuration in which a self-sustaining operation accumulation unit 309 and a self-sustained operation output unit 310 are added to the configuration of the watt-hour meter (FIG. 2) of the first embodiment. May be added to the configuration of the amount of power (FIG. 4).

  According to the watt-hour meter 300 of the present embodiment, it is possible to know the amount of power used for independent operation for each consumer 200, and therefore, calculation of the value according to the exchange of power between the consumers 200 during autonomous operation. Will be able to do.

  DESCRIPTION OF SYMBOLS 101 Distribution line, 102 Switch, 103 Distribution transformer, 104 Lead-in line, 105 Self-sustained operation control system, 106 Communication line, 200 Consumer, 201 Load equipment, 202 Inverter, 203 Solar power generation system, 204 Storage battery, 205 Indoor wiring 300 watt-hour meter, 301 sensor unit, 302 calculation unit, 303 storage unit, 304 output unit, 305 measurement switching unit, 306 signal input unit, 307 self-sustained operation detection unit, 308 metering switching unit, 309 storage unit for self-supporting operation, 310 Output unit for self-sustaining operation.

Claims (3)

A first storage unit capable of accumulating and holding the amount of power flowing through the power distribution system;
A metering switching unit for switching whether to accumulate the amount of power in the first storage unit;
A determination unit that determines whether or not a self-sustained operation using the power distribution system is performed,
The determination unit controls the metering switching unit so that the first accumulation unit does not accumulate the electric energy while the autonomous operation is being performed. Based on the electrical characteristics of the power supplied to the power distribution system, further comprising a self-sustained operation detection unit that detects the start and end of the self-sustained operation,
The watt-hour meter according to claim 1, wherein the determination unit determines whether or not the independent operation is being performed based on a detection result of the independent operation detection unit. A second storage unit capable of accumulating and holding the amount of power flowing through the power distribution system;
The watt-hour meter according to claim 1, wherein the metering switching unit causes the second accumulation unit to accumulate the electric energy while the independent operation is being performed.

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