JP6839760B2 - Power generation system, energy management device, and power generation control method - Google Patents

Description

The present invention relates to a power generation system or the like including one or more distributed power sources including an inverter and cogeneration capable of generating and generating heat.

In recent years, in order to suppress global warming gas, interconnection of distributed power sources such as photovoltaic power generators (PV: Photovoltaic), wind power generators (WF: Wind Firm), and storage batteries to distribution systems has been increasing. Therefore, it is difficult to control the voltage only with the existing voltage control device.

In order to solve this, for example, in Non-Patent Document 1, it is obligatory to install an inverter (smart inverter) capable of adjusting the invalid power for the distributed power source, and the invalid power is controlled in cooperation with the voltage control device of the distribution company. Is disclosed.

In order to realize such voltage / ineffective power control, it is necessary to distribute the ineffective power required for the distribution system to a plurality of distributed power sources and instruct the ineffective power output by the energy management device of the distribution operator. .. As a technique related to ineffective power control, for example, Patent Document 1, Patent Document 2, and Patent Document 3 are disclosed.

U.S. Patent Application Publication No. 2012/0049636 U.S. Patent Application Publication No. 2010/0067271 U.S. Patent Application Publication No. 2010/0138061

Pacific Gas and Electric Company, ELECTRIC RULE NO. 21 GENERATING FACILITY INTERCONNECTIONS

As a method of controlling the disabled power of the distributed power source of the distribution system, as disclosed in Non-Patent Document 1, there is a method of allocating the disabled power output from the distributed power source having a large free capacity of the smart inverter. However, during power generation of the distributed power source, an inverter is used for the active power output, and the capacity that can be used for the invalid power is small, so that the required invalid power may not be output appropriately.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique capable of appropriately outputting the required reactive power.

In order to achieve the above object, the power generation system according to one viewpoint includes one or more distributed power sources including an inverter, cogeneration capable of generating and generating heat, and an energy management device for managing power generation by the distributed power sources and cogeneration. In a power generation system including, the energy management device reduces the amount of active power generated by the distributed power source and switches to the output of the disabled power in order to output the required amount of invalid power. It includes a unit and a cogeneration power control unit that controls the cogeneration to generate the amount of active power to be reduced in the distributed power source.

According to the present invention, the required reactive power can be appropriately output.

FIG. 1 is an overall configuration diagram of a power generation system according to an embodiment. FIG. 2 is a configuration diagram of an energy management device according to an embodiment. FIG. 3 is a diagram showing a configuration example of a heat supply schedule table according to an embodiment. FIG. 4 is a diagram showing a configuration example of a heat dissipation table according to an embodiment. FIG. 5 is a flowchart of the active / reactive power optimization process according to the embodiment. FIG. 6 is a flowchart of the thermoelectric optimization process according to the embodiment.

The embodiment will be described with reference to the drawings. It should be noted that the embodiments described below do not limit the invention according to the claims, and all of the elements and combinations thereof described in the embodiments are indispensable for the means for solving the invention. Is not always.

In the following description, the information is described as a table and the structure of the table, but the information may be represented by any data structure.

Further, in the following description, the "time" is expressed in units of hours and minutes, but the unit of time may be coarser or finer than that, or may be a different unit.

FIG. 1 is an overall configuration diagram of a power generation system according to an embodiment.

The power generation system 1 may be, for example, a small-scale distribution system such as a microgrid or a building system, or an internal system of a large-scale PV power plant. The power generation system 1 includes a transformer 2, a circuit breaker 3, a cogeneration 4, one or more distributed power sources 5, 6, one or more power loads 7, a heat storage tank 8, and one or more heat loads 9. , The energy management device 100 is provided. The circuit breaker 3, the cogeneration 4, the distributed power sources 5 and 6, and the power load 7 are connected via the distribution line 12.

The transformer 2 is connected to the upper distribution system, converts the voltage from the upper distribution system into the voltage on the power generation system 1 side, and supplies the voltage to the circuit breaker 3. Further, the transformer 2 converts the voltage from the power generation system 1 into the voltage on the upper distribution system side and supplies it to the upper distribution system.

The circuit breaker 3 allows a current to pass between the upper side (transformer 2 side) and the lower side (distribution line 12 side) or cuts off the current.

The electric power load 7 executes a predetermined operation by the electric power supplied through the distribution line 12.

The distributed power source 5 (6) includes an inverter 5A (6A) and a photovoltaic (PV) generator 5B (6B). The photovoltaic generator 5B (6B) generates a direct current by sunlight. The inverter 5A (6A) is connected between the photovoltaic generator 5B (6B) and the distribution line 12, and converts the direct current generated by the photovoltaic generator 5B (6B) into an alternating current to convert the distribution line 12 into an alternating current. Supply to. The distributed power source 5 (6) may have a power load inside and may be integrally configured with the power load.

The cogeneration 4 is a system in which a generator (not shown) and a heat exchanger are provided inside, and both electric power and heat are generated and supplied. The cogeneration 4 supplies the generated electric power to the distribution line 12. A heat load 9 and a heat storage tank 8 are connected to the cogeneration 4 via a pipe. The heat load 9 receives heat and executes a predetermined operation. The heat load 9 executes, for example, cooling, heating, and factory production processes. The heat storage tank 8 accumulates the supplied heat, and the accumulated heat can be output to the outside (heat load 9 or the like).

The energy management device 100 is a device that controls the output amount of the active power and the inactive power of the inverter 5A (6A) of the distributed power source 5 (6) and the output power of the cogeneration 4. The energy management device 100 is connected to a management device (distribution management device) (not shown) of an upper distribution system, inverters 5A and 6A, and cogeneration 4 via a communication network. The energy management device 100 calculates the optimum active power and ineffective power according to the instructions from the power distribution management device and the operator, transmits an output command to the inverters 5A, 6A and the cogeneration 4, and transmits the output commands to the inverters 5A, 6A and the cogeneration 4. Controls the output power of generation 4. The energy management device 100 includes a distributed power supply power control unit, an effective / reactive power optimization unit 13 as an example of a request reception unit, and a thermoelectric optimization unit as an example of a cogeneration power control unit, a heat supply control unit, and a schedule management unit. It is provided with a conversion unit 14. The active / reactive power optimization unit 13 performs a process of controlling the output of the active power and the reactive power in the inverters 5A and 6A. The thermoelectric optimization unit 14 performs a process of controlling power generation and heat generation in cogeneration 4.

Next, the configuration of the energy management device 100 will be described.

FIG. 2 is a configuration diagram of an energy management device according to an embodiment.

The energy management device 100 is composed of, for example, a computer, includes a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a communication device 103, and a storage device 104, and includes a CPU 101, a RAM 102, a communication device 103, and the like. And the storage device 104 is connected via the system bus 111.

The CPU 101 executes a predetermined process by executing the program. The RAM 102 temporarily stores a program executed by the CPU 101, data in the middle of calculation by the program, and result data.

The storage device 104 is, for example, a non-volatile storage device composed of a non-volatile memory such as an HDD (hard disk drive) and a flash memory. The storage device 104 stores the program file 105 and the data file 106. The program file 105 includes, for example, an effective invalid power optimization program 107 that is executed by the CPU 101 to form the effective invalid power optimization unit 13, and a thermoelectric program that is executed by the CPU 101 to form the thermoelectric optimization unit 14. There is an optimization program 108. The data file 106 includes a heat supply schedule table 109 and a heat dissipation amount table 110.

The communication device 103 is externally connected, for example, via a wired network such as Ethernet (registered trademark), CAN (Control Area Network), LIN (Local Interface Network), or via a wireless network such as IEEE802.11a or Zigbee. Communicate with the device of. The network used by the communication device 103 may be selected depending on the maintenance status and cost of the public communication network.

Next, the heat supply schedule table 109 will be described.

FIG. 3 is a diagram showing a configuration example of a heat supply schedule table according to an embodiment.

The heat supply schedule table 109 stores entries corresponding to the schedule for executing the heat supply process for the heat load 9. Each entry corresponds, for example, to a schedule of heat supply processes that are repeated daily. It should be noted that the entry may correspond to a single heat supply process.

The entries in the heat supply schedule table 109 include fields for time 109a, heat load ID 109b, heat supply 109c, and executed flag 109d.

The time 109a stores the time (supply time) for supplying heat. The heat load ID 109b stores identification information (heat load ID) of the heat load of the target to which heat is supplied. The heat supply amount 109c stores the heat amount (heat supply amount) to be supplied to the heat load corresponding to the entry. The executed flag 109d stores a flag indicating whether or not the heat supply process corresponding to the entry has been executed. In the present embodiment, the executed flag 109d stores "1" when the heat supply process is executed before the supply time, and "0" when the heat supply process is not executed. To. For example, according to the entry at the top of 1 in the heat supply schedule table 109, at 10:00, a heat amount of "200" is supplied to the heat load 9 having a heat load ID of "02", and this heat supply is performed. Indicates that the processing schedule has already been executed.

Next, the heat dissipation table 110 will be described.

FIG. 4 is a diagram showing a configuration example of a heat dissipation table according to an embodiment.

The heat dissipation table 110 stores an entry indicating the amount of heat dissipated (heat dissipation amount) per unit time for each heat load. The entry in the heat dissipation table 110 includes fields for the heat load ID 110a and the heat dissipation 110b. The heat load ID 110a stores the heat load ID of the heat load 9 corresponding to the entry. The heat radiation amount 110b stores the heat radiation amount radiated in a unit time (for example, 1 hour) in the heat load 9 corresponding to the entry.

Next, the processing operation in the power generation system 1 will be described.

FIG. 5 is a flowchart of the active / reactive power optimization process according to the embodiment.

The effective invalid power optimization process is executed, for example, when an invalid power output request (Q output request) is input to the energy management device 100. In the present embodiment, the ineffective power output request includes an ineffective power amount (invalid power output request amount Qr) that is further required to be added to the ineffective power at that time in the power generation system 1. The invalid power output request may be input from the management device of the upper distribution system via the network, or may be input by the operator via a console (not shown).

When the Q output request is input, the effective / reactive power optimization unit 13 of the energy management device 100 receives the Q output request (step S101), and the inverters 5A and 6A of the distributed power sources 5 and 6 receive the inverters 5A, respectively. The output of the active power of 6A (active power output amount) and the power factor are read (step S102).

Next, the effective / reactive power optimization unit 13 obtains the free capacity of each of the inverters 5 and 6 based on the read active power output amount and the power factor (step S103). Next, the effective and ineffective power optimization unit 13 calculates the total Ct of the amount of ineffective power that can be output from the free capacity of all the inverters (step S104).

Next, the active / reactive power optimization unit 13 compares the total Ct of the amount of invalid power that can be output with the amount of the invalid power output request Qr indicated by the invalid power output request (step S105). As a result, when the total Ct of the amount of ineffective power that can be output is equal to or greater than the amount of ineffective power output required Qr (step S105: Yes), the inverters 5A and 6A are used to output the current active power. Since it means that the invalid power corresponding to the invalid power output request amount Qr can be output, the effective invalid power optimization unit 13 divides the invalid power output request amount Qr so that each of the inverters 5A and 6A can output ( Step S110). Here, as a method of dividing the required amount of reactive power output, when the output of the reactive power is increased in each of the inverters 5A and 6A, the voltage at the interconnection point of each of the inverters 5A and 6A is the voltage determined by the standard. The voltage is calculated by the power flow calculation so as not to deviate from the range. Next, the effective and ineffective power optimization unit 13 transmits an ineffective power output request for outputting the divided ineffective power amount to each of the inverters 5A and 6A (step S111), and ends the process.

On the other hand, when the total Ct of the amount of invalid power that can be output is not equal to or greater than the required amount of invalid power output Qr (step S105: No), the inverters 5A and 6A output the invalid power while the current active power is being output. Since it means that the ineffective power corresponding to the required amount Qr cannot be output, the effective ineffective power optimizing unit 13 determines that the ineffective power output required amount Qr is the amount of active power being output by the plurality of inverters 5A and 6A. It is determined whether or not it is less than or equal to the total (step S106).

As a result, when the ineffective power output request amount Qr is equal to or less than the total amount of active power being output by the plurality of inverters 5A and 6A (step S106: Yes), the output of the active power by the plurality of inverters 5A and 6A By reducing the number of powers, it means that the powers corresponding to the power output request amount Qr can be output. Therefore, the effective power optimization unit 13 requests the free capacity Qa of the inverter additionally required for the power output. The thermoelectric optimization process is performed by the thermoelectric optimization unit 14 with Pa = Qa as an argument so that the amount of power generation Pa in the cogeneration 4 becomes the same value as the free capacity Qa, which is obtained by the quantity Qr-total Ct (see FIG. 6). Is executed (step S108).

Next, the active / inactive power optimization unit 13 changes (reduces) the output (P output) of the active power by the plurality of inverters 5A and 6A so that the ineffective power corresponding to the ineffective power output request amount QR can be output (reduced). Step S109), the process proceeds to step S110.

On the other hand, when the invalid power output request amount Qr is not less than or equal to the total amount of active power being output by the plurality of inverters 5A and 6A (step S106: No), the output of the active power by the plurality of inverters 5A and 6A is reduced. However, since it means that the invalid power corresponding to the invalid power output request amount Qr cannot be output, the effective invalid power optimization unit 13 outputs an error (step S107) and ends the process.

According to the above-mentioned active / reactive power optimization process, the inverters 5A and 6A can appropriately output the invalid power corresponding to the invalid power output request amount Qr.

Next, the thermoelectric optimization process will be described.

FIG. 6 is a flowchart of the thermoelectric optimization process according to the embodiment.

The thermoelectric optimization process corresponds to the process in step S108 of FIG.

The thermoelectric optimization unit 14 specifies the calorific value J by the cogeneration 4 when the corresponding power generation amount is generated by the cogeneration 4 based on the argument from the effective and ineffective power optimization unit 13 (for example, calculation or calculation or Search from the table) (step S201). The relationship between the amount of power generated by cogeneration 4 and the amount of heat generated at that time is measured in advance by experiments to specify the relational expression or create a table showing the correspondence. There is a need to. Next, from the heat supply schedule table 109, when the thermoelectric optimization unit 14 supplies the heat generation amount J to the heat load from the current time, the heat supply amount required at the supply time remains even if the heat dissipation amount is taken into consideration. Search for an unexecuted heat supply schedule (step S202).

In the heat supply schedule table 109, the thermoelectric optimization unit 14 shows a heat supply schedule (corresponding heat supply schedule) that satisfies the required heat supply amount at the supply time by the amount of heat generated when power is generated by the cogeneration 4, that is, the current heat supply schedule. When the calorific value J is supplied to the heat load from the time, it is determined whether or not there is an unexecuted heat supply schedule in which the required heat supply amount remains at the supply time even if the heat dissipation amount is taken into consideration (step S203). .. Specifically, the thermoelectric optimization unit 14 determines the amount of heat released per unit time of the heat load corresponding to the heat supply schedule for each of the unexecuted heat supply schedules in the heat supply schedule table 109. Obtained from the table 110, the total amount of heat radiated during that time is calculated based on the amount of heat radiated per unit time and the time from the current time to the supply time of the heat supply schedule, and the total amount of heat radiated is subtracted from the amount of heat generated J. Whether or not there is a corresponding heat supply schedule is determined based on whether or not the amount of heat generated is equal to or greater than the amount of heat supplied by the heat supply schedule.

As a result, when there is a corresponding heat supply schedule (step S203: Yes), it means that the amount of heat generated by the cogeneration 4 can be effectively used for the corresponding heat supply schedule. Changes the flag of the executed flag 109d of the entry corresponding to the corresponding heat supply schedule in the supply schedule table 109 to executed (step S204), starts the power generation of the cogeneration 4 (step S205), and causes the corresponding heat supply schedule. The heat supply to the heat load 9 corresponding to the above (step S206) is started (step S206), and the thermoelectric optimization process is completed.

On the other hand, when there is no corresponding heat supply schedule (step S203: No), it means that the heat supply schedule cannot be realized only by the amount of heat generated by the cogeneration 4, so that the thermoelectric optimization unit 14 , The power generation of the cogeneration 4 is started (step S207), the heat supplied by the cogeneration 4 to the heat storage tank 8 is started (step S208), and the thermoelectric optimization process is completed.

According to this thermoelectric optimization process, when the amount of power insufficient to secure the ineffective power in the inverters 5A and 6A is covered by the power generation by the cogeneration 4, if there is a heat supply schedule that is satisfied by the amount of heat generated during the power generation. By supplying heat to the heat load that is the target of the heat supply schedule, it is possible to realize the state in which the required heat supply is performed at the supply time of the heat supply schedule, and later this heat supply schedule. Eliminates the need to run. Further, if there is no heat supply schedule that is satisfied by the amount of heat generated during the power generation of the cogeneration 4, the generated heat is stored in the heat storage tank 8, so that the heat of the heat storage tank 8 is used at the time of later heat supply. It is possible to suppress the consumption of fuel at that time. Further, in the present embodiment, when there is a heat supply schedule that is satisfied by the amount of heat generated during the power generation of the cogeneration 4, it is not necessary to accumulate heat in the heat storage tank 8, so that the heat storage capacity required in the heat storage tank 8 is required. Can be reduced, and the cost required for the heat storage tank 8 can be reduced.

As described above, according to the present embodiment, the output of the active power in the inverters 5A and 6A is reduced, and the capacity required for outputting the invalid power corresponding to the invalid power output request amount QR is secured. Since the active power to be reduced is secured by using the power generation of the cogeneration 4, the capacity required for the inverters 5A and 6A can be reduced, and the cost of the inverters 5A and 6A can be reduced. it can.

The present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present invention.

For example, in the above embodiment, as an invalid power output request, a request is made to output an invalid power amount that is a difference from the invalid power amount in the current power generation system 1, but the present invention is not limited to this, and for example, the invalid power. As an output request, it may be the total amount of invalid power to be output in the power generation system 1.

Further, in the above embodiment, the heat storage tank 8 is provided, but the present invention is not limited to this, and the heat storage tank 8 may not be provided. Further, in the above embodiment, if the cogeneration 4 has a heat supply schedule that is satisfied by the amount of heat generated during power generation, heat is immediately supplied to the heat load 9 that is the target of the heat supply schedule. Is not limited to this, and the heat generated during power generation by the cogeneration 4 may be stored in the heat storage tank 8.

Further, in the above embodiment, the configuration corresponds to a microgrid having a power load 7 in the power generation system 1, but the present invention is not limited to this, and the power load 7 is not provided in the power generation system 1. May be good.

Further, in the above embodiment, the distributed power sources 5 and 6 are provided with a solar power generator, but the distributed power source is not limited to this, and for example, a wind power generator is used instead of at least one solar power generator. You may be prepared.

Further, in the above embodiment, a part or all of the processing performed by the CPU may be performed by the hardware circuit. In addition, the program in the above embodiment may be installed from the program source. The program source may be a program distribution server or storage media (eg, portable storage media).

1 ... Power generation system, 4 ... Cogeneration, 5, 6 ... Distributed power supply, 5A, 6A ... Inverter, 5B, 6B ... Photovoltaic generator, 7 ... Power load, 8 ... Heat storage tank, 9 ... Heat load, 100 ... Energy Management device

Claims (12)

A power generation system including one or more distributed power sources including an inverter, cogeneration capable of power generation and heat generation, and an energy management device for managing power generation by the distributed power sources and the cogeneration.
The energy management device
In order to output the required amount of invalid power, the distributed power supply control unit that reduces the amount of active power generated by the distributed power source and switches to the output of the disabled power.
A cogeneration power control unit that controls the amount of active power to be reduced in the distributed power source so that the cogeneration can generate power.
Power generation system equipped with. The power generation system further comprises a heat load that can utilize heat.
The power generation system according to claim 1, wherein the energy management device further includes a heat supply control unit that supplies heat generated by the cogeneration to the heat load. Further, a storage unit for storing a schedule including the amount of heat supplied and the time of supply under the heat load is provided.
The heat supply control unit specifies a schedule that satisfies the heat supply amount at the supply time based on the heat amount generated when the active power amount is generated by the cogeneration, and the heat load corresponding to the schedule is applied to the heat supply. The power generation system according to claim 2, wherein the heat generated by the generation is supplied. The power generation system further includes a heat storage tank for storing heat.
The power generation system according to claim 3, wherein the heat supply control unit supplies the heat generated by the cogeneration to the heat storage tank when there is no schedule satisfied with the amount of heat generated by the cogeneration. The energy management device
The power generation system according to claim 3, further comprising a schedule management unit that determines that the schedule has been executed when the amount of heat is supplied to the heat load corresponding to the specified schedule. The power generation system further includes a heat storage tank for storing heat.
The power generation system according to claim 1, wherein the energy management device further includes a heat supply control unit that supplies heat generated by the cogeneration to the heat storage tank. The energy management device
The power generation system according to any one of claims 1 to 6, further comprising a request receiving unit for receiving a request for a required amount of invalid electric power. The power generation system is connected to the upper distribution system and
The request receiving unit, the power generation system of claim 7, receiving a request for reactive energy required from the upper distribution system. The power generation system according to any one of claims 1 to 8, further comprising a power load that utilizes electric power. The power generation system according to any one of claims 1 to 9, wherein the distributed power source includes a solar power generator or a wind power generator. An energy management device that manages power generation by the distributed power sources and the cogeneration in a power generation system including one or more distributed power sources including an inverter and cogeneration capable of generating and generating heat.
In order to output the required amount of invalid power, the distributed power supply control unit that reduces the amount of active power generated by the distributed power source and switches to the output of the disabled power.
A cogeneration power control unit that controls the amount of active power to be reduced in the distributed power source so that the cogeneration can generate power.
Energy management device equipped with. A power generation control method using a power generation system including one or more distributed power sources including an inverter, cogeneration capable of power generation and heat generation, and an energy management device for managing power generation by the distributed power sources and the cogeneration.
A step of reducing the amount of active power generated by the distributed power source and switching to the output of the ineffective power in order for the energy management device to output the required amount of ineffective power.
A step in which the energy management device controls the cogeneration to generate an amount of active power to be reduced in the distributed power source.
Power generation control method including.