JP2008067484A - Private power generation system obtained by combining storage battery facility and privately-owned electrical power facility and control method for output of privately-owned electrical power facility in the system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a utility-connected private power generation system wherein a storage battery facility and a privately-owned electrical power facility can be controlled, in an integrated manner and a control method for the output of the privately-owned electrical power facility in this system. <P>SOLUTION: The private power generation system 1 connected to a system power supply 3 includes a privately-owned electrical power facility 11 whose output is controllable; a storage battery facility 12 constructed of a storage battery 121 that can be charged/discharged and an output controlling means 122 for controlling charging/discharging current; an interconnection line load flow detection unit 16 that detects a load flow in an interconnection line 31; a storage battery facility output detection unit 17 that detects the charging/discharging power of the storage battery facility 12; and a privately-owned electrical power facility output control means. The storage battery facility 12 controls the output of a storage battery so that the interconnection line load flow becomes equal to a set value of interconnection line load flow, based on fluctuation in interconnection line load flow. The privately-owned electrical power facility controls the output of a privately-owned electrical power facility so that the sum of the interconnection line load flow and the output of the storage battery becomes equals the set value of interconnection line load flow. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a private power generation system that combines a private power generation facility and a storage battery facility that are grid-connected to a power system, and an output control method for the private power generation facility in the system.

  In a system in which the private power generation equipment 11 capable of output control as shown in FIG. 5 is connected to the power grid 3, a reverse power flow is prevented against fluctuations in the loads 13-1 to 3-n on the premises, etc. For this reason, “power reception constant control” is performed to maintain the power flow (interconnection line flow) at the interconnection point at a constant value (range), and the private power generation facility 11 has the function. ing. In this received power constant control, the tidal current set value of the target interconnecting line 31 is determined, the interconnecting line power detecting means 16 measures the interconnecting line power flow, is converted into a current signal, etc., and sent to the private power generation facility 11. Then, based on the signal, the output of the private power generation facility 11 is controlled, and as a result, the interconnection current flows close to the interconnection current setting value.

  On the other hand, in recent years, the introduction of solar power generation facilities and wind power generation facilities has progressed. However, the output of these power generation facilities fluctuates depending on weather conditions. It is said that it is necessary to do. As equipment for complementing fluctuations, storage battery equipment having a charge / discharge function and private power generation equipment capable of output control are considered. Among these, a storage battery facility having a charge / discharge function can have a high-speed response (variation compensation), but has a disadvantage that a loss due to charge / discharge occurs or a charge / discharge amount is finite. The private power generation facility capable of output control has a characteristic that output control is possible as long as fuel supply continues, although the response speed is low.

  Therefore, an in-house power generation system that combines both of these features as shown in FIG. 3 is effective. In this private power generation system, the power flow of the connection line 31 (connection line power flow) is monitored by the connection line power flow detection means 16, and output fluctuations of natural power sources such as the solar power generation equipment 14 and the wind power generation equipment 15 are detected. When the interconnection current (electric power) of the interconnection line 31 exceeds a preset set power due to fluctuations in the loads 13-1 to 13-n, both the storage battery facility 12 and the private power generation facility 11 have exceeded. Operates to supplement power. At this time, the storage battery facility 12 can quickly respond to the load fluctuation and operates to suppress the interconnection current to the set power, so that the interconnection current is returned to the set power. However, since the private power generation facility 11 responds slowly to the load fluctuation, the interconnection power flow returns to the set power by complementation by the storage battery equipment 12 until the load fluctuation is dealt with. As a result, the interconnection power flow Can not cope with the fluctuations of As a result, the storage battery facility 11 continues to be discharged, resulting in a problem that the power charged in the storage battery 121 is eventually exhausted.

  In order to solve such a problem, as shown in FIG. 4, the integrated control device 5 is connected to the grid-connected private power generation system in which the private power generation system 1 and the power system 3 are interconnected via the interconnection line 31. It is conceivable to provide it. The in-house power generation system 1 includes an in-house power generation facility 11 capable of output control such as cogeneration, a storage battery facility 12 including a storage battery 121 and a bidirectional converter 122 capable of controlling charge / discharge amount, a solar power generation facility 14 and wind power generation. The facility 15 is connected by a power line 19, and many loads 13-1 to 13-n are connected. The interconnecting line power flow detecting means 16 detects the interconnecting line power flow and is connected to the integrated control device 5. In such a grid interconnection private power generation system, the integrated control device 5 monitors the interconnection line flow with the interconnection line flow detection means 16, and the response speed of the storage battery facility 12 and the private power generation facility 11 with respect to load fluctuations, the storage battery facility. Controlling the output sharing of each facility while taking into account the charging / discharging state of the power generation, the output state of the private power generation facility, etc., and overall control so that the interconnection power flow becomes constant.

  Such an integrated control device 5 can be highly controlled, but has the following problems and is generally expensive. Communication between the integrated control device, the private power generation facility, and the power storage facility is required. However, if the communication method is different between the respective devices and facilities, a signal conversion device is required, and the system becomes complicated. When the private power generation facility is an existing facility, it is difficult to control the output of the private power generation facility in response to an output command from the integrated control system unless the private power generation facility is compatible with the integrated control system. Since a control loop is built outside the local control performed by the power storage facility 12 or the private power generation facility 11, the entire control including measurement and communication takes time, and unnecessary charging or discharging increases. As a result, the capacity of the power storage facility becomes large, and the loss increases as the charge / discharge increases.

  In addition, there has been proposed a self-power generation system linked to a power system, in which a self-power generation facility and a storage battery facility are combined to perform zero flow control. This system is a power supply device that is used in a system in which a commercial power supply and a generator are linked to supply additional AC power through a power supply line, and an active filter circuit connected to the power supply line and an active power supply A storage battery connected to the subsequent stage of the filter circuit, and a control circuit for controlling the operation of the active filter circuit and the charging / discharging operation of the storage battery. A system that performs zero power flow control (see, for example, Patent Document 1).

  This private power generation system includes a control circuit that controls the operation of the active filter circuit and the charge / discharge operation of the storage battery, and is a control circuit that complements the response delay due to the slow response of the generator at the time of load fluctuation with the storage battery. It corresponds to the integrated control device.

  In addition, in a cogeneration system that performs constant control of received power, where the received power flow is not constant due to the cogeneration follow-up delay, the capacitor power storage device is used as the power receiving system as an instantaneous received power control system connected to the power system. A capacitor power storage device having a parallel monitor that includes a plurality of capacitors and is connected in parallel to each of the capacitors to perform detection of a charging voltage and bypass control, and an instantaneous received power control system that connects and controls received power. An AC / DC converter connected to the power receiving system to convert between AC and DC to charge / discharge the capacitor power storage device, and a system monitoring power control apparatus to monitor the power receiving system and control the AC / DC converter (For example, refer to Patent Document 2).

This instantaneous received power control system is intended to make the received power flow constant by the capacitor, but requires a device corresponding to an integrated control device called a system monitoring power control device.
JP 2003-70165 A JP 2001-2111549 A

  The present invention provides a grid-connected private power generation system capable of integrating and controlling storage battery equipment and private power generation equipment without having an integrated control device, and an output control method for the private power generation equipment in this system The purpose is to do.

  Furthermore, an object of the present invention is to provide a grid-connected private power generation system that enables a high-speed control with a simple control loop.

  In order to solve the above problems, the present invention provides an output control method of a private power generation facility in a private power generation system linked to a power system, wherein the private power generation system includes a storage battery facility and a private power generation facility, The storage battery equipment controls the storage battery output based on the fluctuation of the connection power flow so that the connection power flow becomes the connection power flow setting value, and the private power generation equipment has a sum of the connection power flow and the storage battery output. The output of the in-house power generation equipment is controlled so that the interconnected power flow becomes the interconnected power flow set value.

  Furthermore, the present invention provides the output control method for an in-house power generation facility, wherein the in-house power generation system includes an in-house power generation facility capable of controlling a power generation amount, a chargeable / dischargeable storage battery, and an output control means for controlling a charge / discharge current. It has a storage battery facility, a connection line power flow detection unit for detecting a power flow of the connection line, a storage battery facility output detection unit for detecting charge / discharge power of the storage battery facility, and a private power generation facility output control means.

  Further, the present invention provides an in-house power generation system linked to an electric power system, wherein the in-house power generation system controls an in-house power generation facility capable of controlling the amount of power generation, a chargeable / dischargeable storage battery, and a charge / discharge current. A storage battery facility comprising: an interconnection line power flow detection unit for detecting the flow of the interconnection line; a storage battery facility output detection unit for detecting charge / discharge power of the storage battery facility; and a private power generation facility output control means. The storage battery equipment controls the storage battery output based on the fluctuation of the interconnection power flow so that the interconnection power flow becomes the connection power flow setting value, and the private power generation equipment is the sum of the interconnection power flow and the storage battery output. Controls the output of the private power generation facility so that becomes the interconnected power flow set value.

  By having the above-described configuration, the in-house power generation system connected to the grid according to the present invention is configured so that the storage battery facility becomes set power based on the grid power flow when the grid power flow exceeds the set power. Complementary, since the private power generation equipment complements the sum of the grid power flow and the storage battery equipment output to be the set power, the integrated control device It is possible to integrate and control the storage battery facility and the private power generation facility without having the power. Further, the grid-connected private power generation system of the present invention has a simple control loop, and can be controlled at low cost and at high speed.

  The present invention relates to a grid-connected private power generation system that monitors the interconnection power flow and controls the output of the storage battery equipment, and controls the private power generation equipment using the interconnection power flow signal and the storage battery output signal. Features. In other words, in the present invention, the signal input to the private power generation facility is a value obtained by adding the output from the storage battery facility to the interconnected power flow, and is a value larger by the output of the storage battery facility than the excess of the actual power flow. . Therefore, when the interconnection power flow exceeds a preset allowable interconnection flow value (hereinafter sometimes referred to as the interconnection flow setting value), the storage battery equipment supplements the interconnection flow. The private power generation facility outputs power so as to complement the interconnected power flow. The storage battery facility reduces the output of the private power generation facility as the output increases, and finally, the output of the private power generation facility supplements the excess of the interconnection power flow.

  Hereinafter, the configuration of the grid-connected private power generation system according to the present invention will be described with reference to FIG. The grid-connected private power generation system according to the present invention is configured by interconnecting the private power generation system 1 and the power system 3 via a connection line 31. The private power generation system 1 includes a private power generation facility 11 capable of controlling output such as cogeneration, a storage battery 121, a storage battery facility 12 including a bidirectional converter 122 capable of controlling a charging current and a discharging current, a solar power generation facility 14, and It is configured by connecting a naturally fluctuating power source such as a wind power generation facility 15 with a power line 19, and further includes an interconnection line power flow detection means 16, a storage battery facility output detection means 17, and an adder 18. Loads 13-1 to 13-n are connected.

  The private power generation facility 11 is a private power generation facility capable of output control such as cogeneration, and has an output control unit (not shown). The output control unit of the private power generation facility 11 uses a value obtained by adding the storage battery facility output to the connection line flow as an apparent connection line flow signal to obtain a control target value that exceeds the set value of the connection line flow. The output of the private power generation facility 11 is controlled by this control target value.

  The storage battery facility 12 includes a storage battery 121 such as a lead battery, and a bidirectional converter 122 that controls the charge / discharge direction, the charge current, and the discharge current of the storage battery 121. The storage battery facility 12 has a function (local control) for controlling to maintain the interconnection line flow at the interconnection line flow set value by the interconnection line flow. The bidirectional converter 122 receives the tidal current signal from the interconnection power flow detection means 16 and compares it with the interconnection power flow setting value. When the interconnection power flow exceeds the interconnection power flow setting value, The output current from the storage battery 121 is controlled so as to complement the excess power flow value. Further, the bidirectional converter 122 is controlled so as to charge the storage battery 121 with a surplus of the tidal current in a state in which the telecommunication current flows below the interconnecting power flow set value. The configuration of bidirectional converter 122 is well known, and a description of the configuration and operation is omitted.

  The loads 13-1 to 13-n are loads that are turned on / off to the power line 19, and load fluctuations are caused by the on / off of the respective loads.

  The photovoltaic power generation facility 14 is a natural variation power generation facility whose output fluctuates depending on the presence or absence of sunlight or the magnitude of the sunshine, and causes fluctuations in the interconnected power flow due to fluctuations in the output. Further, the wind power generation facility 15 is a natural variation power generation facility whose output fluctuates depending on the presence / absence of the wind and the air volume, and causes fluctuations in the interconnected power flow due to fluctuations in the output. In the present invention, the solar power generation facility 14 and the wind power generation facility 15 can be viewed as negative loads, and these can be omitted.

  The interconnecting line power flow detection means 16 is a means for detecting the power flow of the interconnecting line and outputting an interconnecting line power flow signal, and can be configured by a CT, a VT, a transducer, or the like.

  The storage battery facility output detection means 17 is means for detecting the output of the storage battery and outputting a storage battery output signal, and can be constituted by a CT, a VT, a transducer, or the like.

  The adder 18 is a means for adding the interconnection line power flow signal and the storage battery output signal and outputting an addition signal, and outputs an apparent interconnection line power flow signal. The adder 18 can be configured by using an addition transducer or a sequencer.

  When the private power generation system 1 having such a configuration is connected to the power system 3 through the connection line 31, if the connection line flow exceeds the connection line flow set value, the connection detected by the storage battery facility 12 Power is output from the storage battery 121 to the power line 19 based on the line power flow signal, and the private power generation facility 11 outputs to the power line 19 using an apparent connection power flow signal obtained by adding the storage battery facility output signal to the connection power flow signal. Is controlled.

  A mode of change in output of each facility will be described with reference to FIG. When the load power does not fluctuate at a constant value, power is supplied from the private power generation facility so that the interconnected power flow becomes the interconnected power flow set value, and the output of the storage battery facility is “0”. When the load power increases at time A, the interconnecting power flow exceeds the interconnecting power flow set value, and the interconnecting power flow signal is supplied to the storage battery facility and the private power generation facility. The storage battery facility quickly follows the fluctuation of the interconnection power flow, increases its output, and lowers the interconnection power flow to the connection power flow setting value. However, the private power generation facility increases its output by a slow response based on the apparent interconnected power flow signal that is the sum of the interconnected power flow signal and the battery output signal. As the output of the private power generation facility increases, the output of the storage battery facility gradually decreases so that the interconnected power flow is maintained at the interconnected power flow set value. When the output of the private power generation facility finally becomes a value that can cope with the load fluctuation, the output of the storage battery becomes “0”, and the interconnected power flow is maintained at the interconnected power flow set value only by the output of the private power generation facility.

  In the above description, the case where the load 13 fluctuates so that the interconnecting line power flow exceeds the interconnecting line power flow setting has been described. However, in the case where the load fluctuates so that the interconnecting line power flow falls below the interconnecting line power flow setting. First, the storage battery facility 12 is quickly charged so as to absorb the decrease in interconnection power flow accompanying the decrease in load, and the in-house power generation facility 11 slowly decreases the output as the load decreases. Thus, it is possible to cope with a sudden decrease in load. In this case, in the adder 18, the storage battery output signal added to the interconnection power flow signal is a negative value.

  In this way, in a private power generation system equipped with storage battery equipment and private power generation equipment with different response speeds against sudden load fluctuations, the storage battery equipment first shares the load during sudden load fluctuations, and then the private power generation equipment is surely The load can be shared.

The figure explaining the structure of the private electric power generation system connected to the electric power grid | system which concerns on this invention. The figure explaining the mode of operation of the private power generation system concerning the present invention. The figure explaining the structure of the private electric power generation system which has the storage battery equipment connected to the simple electric power system. The figure explaining the structure of the private electric power generation system which has the storage battery equipment connected to the electric power grid | system using an integrated control apparatus. The figure explaining the structure of the private electric power generation system connected with the simple electric power grid | system.

Explanation of symbols

  1: Private power generation system, 11: Private power generation facility, 12: Storage battery facility, 121: Storage battery, 122: Bidirectional converter, 13: Load, 14: Solar power generation facility, 15: Wind power generation facility, 16: Grid power flow Detection means, 17: storage battery output detection means, 18: adder, 19: power line, 3: power system, 31: interconnection line, 5: integrated control device

Claims (3)

In the output control method of the private power generation facility in the private power generation system linked to the power system,
The private power generation system includes a storage battery facility and a private power generation facility,
The storage battery equipment controls the storage battery output based on the fluctuation of the interconnection current, so that the interconnection current becomes the interconnection current setting value,
The output of the private power generation facility is characterized in that the private power generation facility controls the output of the private power generation facility based on the sum of the interconnection power flow and the storage battery output so that the interconnection power flow becomes a connection power flow setting value. Control method. In the private power generation facility output control method according to claim 1,
The in-house power generation system includes an in-house power generation facility capable of controlling the amount of power generation, a storage battery facility comprising a chargeable / dischargeable storage battery and output control means for controlling charge / discharge current, and an interconnected line power flow for detecting the power flow of the interconnected line. An output control method for a private power generation facility, comprising: a detection unit; a storage battery facility output detection unit for detecting charge / discharge power of the storage battery facility; and a private power generation facility output control means. In the private power generation system linked to the grid power supply,
The in-house power generation system is
In-house power generation equipment that can control power generation,
A storage battery facility comprising a chargeable / dischargeable storage battery and an output control means for controlling the charge / discharge current;
An interconnecting line tidal current detector that detects the tidal current of the interconnecting line;
A storage battery facility output detector for detecting charge / discharge power of the storage battery facility;
It has private power generation facility output control means,
The storage battery equipment controls the storage battery output based on fluctuations in the interconnection power flow so that the interconnection power flow becomes the connection power flow setting value, and the private power generation equipment is the sum of the interconnection power flow and the storage battery output. Is a private power generation system that controls the output of the private power generation equipment so that the power flow setting value becomes the interconnection line power setting value.

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