JP5631712B2 - Control system, control circuit constituting the control system, distributed power source provided with the control circuit, and server constituting the control system - Google Patents

Description

  The present invention relates to a control system including a control circuit for PWM control of an inverter circuit that converts DC power to AC power, and a server that transmits and receives information between the control circuits, and a control that configures the control system The present invention relates to a circuit, a distributed power supply including the control circuit, and a server constituting the control system.

  In recent years, distributed power sources have been developed that convert DC power generated by solar cells, fuel cells, and the like into AC power by an inverter and output the AC power. These distributed power supplies are connected to an existing power system and supply power to the power system. A synchronous generator that generates power using thermal power or nuclear power is connected to the power system, and a distributed power source is also connected in parallel with the synchronous generator.

  In order to perform synchronous operation, the synchronous generator on the power system supplies active power from the synchronous generator whose phase is advanced to the synchronous generator whose phase is delayed. Since this active power acts to synchronize the phase, it is called synchronized power. The phase of each synchronous generator is adjusted because the phase of the synchronous generator to which the synchronized power is supplied is delayed and the phase of the synchronized generator to which the synchronized power is supplied is advanced. The force for adjusting the phase is represented by a change amount of the synchronization power with respect to the change amount of the phase, and is called a synchronization force of the synchronous generator. As a result of this synchronization force acting between the synchronous generators, even if the rotational speed of the rotor of any synchronous generator changes temporarily, the phase of Adjustments are made. Thereby, the electric power system is kept stable. However, when a large amount of distributed power sources that do not have synchronization power are connected to the power system, it is predicted that the synchronization of the power system will be impaired because the synchronization power is not properly transferred.

  Further, in order to supply stable and high-quality power in the power system, the synchronous generator performs frequency control for keeping the frequency of the power system at a reference frequency. When the frequency of the power system rises, the power generation equipment may be dropped from the power system, and the power generation equipment may drop out in a chain due to the burden on other power generation equipment. Since this phenomenon makes the power system unstable, frequency control is performed to prevent this phenomenon. The synchronous generator adjusts the output power based on the detected change in the system frequency so as to maintain the power supply-demand balance. Thereby, the system frequency of the power system is kept stable. However, when a large number of distributed power sources that do not perform frequency control are connected to the power system, the system frequency is not properly controlled and the stability of the system frequency of the power system is expected to be impaired. .

  In order to maintain the stability of the power system even when the distributed power source is connected to the power system in large quantities, a distributed power source that has synchronization power and performs frequency control has been developed.

JP 2010-161901 A

  However, if each distributed power source connected to the power system individually controls, there is a possibility that the supply of power becomes excessive on the power system or the suppression becomes excessive. In this case, the stability of the power system is impaired. In addition, if the power supply is suppressed for the stability of the power system, the person who supplies the power loses the opportunity for power generation. Therefore, in order to suppress power supply, it is necessary to make each distributed power source equal.

  The present invention has been conceived under the circumstances described above, and even when a plurality of distributed power sources are connected to the power system, the power generation opportunity of each distributed power source can be obtained without impairing the stability of the power system. It is an object of the present invention to provide a control system that can equalize the loss.

  In order to solve the above problems, the present invention takes the following technical means.

A control system provided by the first aspect of the present invention includes an inverter circuit that includes an inverter circuit that converts DC power into AC power, and is provided in each of a plurality of distributed power supplies that supply the AC power to a power system. A control system including a control circuit for PWM control and a server that transmits and receives information to and from each control circuit, wherein each control circuit detects a phase of the power system and detects the phase A phase change amount calculating means for calculating a change amount of the power, an electrical information transmitting means for transmitting electrical information relating to the output of the distributed power source to the server, calculation information received from the server, and the phase change amount . And a command value signal generating means for generating a command value signal for commanding a voltage signal output from the inverter circuit, and a PWM signal based on the command value signal. And a PWM signal generating means for forming, before Symbol server, based on said electrical information received from the control circuit, and the information calculating means for calculating the calculated information respectively corresponding to the output of said each distributed power source And information transmitting means for transmitting each of the calculated information calculated by the information calculating means to the corresponding control circuit.

  In a preferred embodiment of the present invention, the information calculation means includes coefficient calculation means for calculating a coefficient based on a ratio of the electrical information to a total value of the electrical information received from the control circuits. Yes.

  In a preferred embodiment of the present invention, each of the control circuits further includes an active power calculating unit that calculates a power value of active power output from the distributed power source, and the electrical information transmitting unit is the active power calculating unit. Is transmitted as the electrical information.

In a preferred embodiment of the present invention, each of the control circuit, before SL on the basis of the phase change amount and the correction value calculated from the coefficients, further comprising a target correction means to correct the target value of the output active power The command value signal generating means generates a command value signal for making the power value calculated by the active power calculating means coincide with the corrected target value corrected by the target correcting means.

  In a preferred embodiment of the present invention, the information transmission means transmits the coefficients calculated by the coefficient calculation means to the corresponding control circuits as the calculation information, respectively, And a correction value calculation means for calculating the correction value by multiplying the phase change amount calculated by the phase change amount calculation means by the coefficient received from the server.

  In a preferred embodiment of the present invention, each control circuit further comprises phase change amount transmitting means for transmitting the phase change amount calculated by the phase change amount calculating means to the server, wherein the information calculating means is Each of the coefficients calculated by the coefficient calculation means is multiplied by the phase change amount received from the corresponding control circuit, and further includes correction value calculation means for calculating the correction values. The information transmitting unit transmits the correction value calculated by the correction value calculating unit to the corresponding control circuit as the calculation information.

  In a preferred embodiment of the present invention, each control circuit includes phase change amount transmitting means for transmitting the phase change amount calculated by the phase change amount calculating means to the server, and each of the control circuits received from the server. Correction value calculation means for calculating the correction value from calculation information, wherein the information calculation means calculates a phase change amount reference value that is an average value or a median value of the phase change amounts received from the control circuits. A phase change amount reference value calculating unit, wherein the information transmitting unit includes the coefficients calculated by the coefficient calculating unit and the phase change amount reference value calculated by the phase change amount reference value calculating unit. Is transmitted to the corresponding control circuit as each calculation information, and the correction value calculation means receives the coefficient and the phase change amount base received from the server. By multiplying the value, to calculate the correction value.

  In a preferred embodiment of the present invention, each control circuit further comprises phase change amount transmitting means for transmitting the phase change amount calculated by the phase change amount calculating means to the server, wherein the information calculating means is A phase change amount reference value calculating means for calculating a phase change amount reference value that is an average value or a median value of the phase change amounts received from the control circuits, the coefficients calculated by the coefficient calculating means, The information transmission means further includes correction value calculation means for multiplying the phase change quantity reference value calculated by the phase change quantity reference value calculation means to calculate each of the correction values. The correction value calculated by the above is transmitted as the calculation information to the corresponding control circuits.

  In a preferred embodiment of the present invention, each control circuit includes phase change amount transmitting means for transmitting the phase change amount calculated by the phase change amount calculating means to the server, and the information calculating means includes: And a positive / negative discriminating unit for discriminating whether the phase change amount received from each control circuit is a positive value or a negative value, and the coefficient calculating unit has a positive value for the phase change amount. First coefficient calculation means for calculating a coefficient based on a ratio of the electrical information received from each control circuit to a total value of the electrical information received from each control circuit determined to be, and the phase A coefficient based on the ratio of the electrical information received from each control circuit to the total value of the electrical information received from each control circuit determined that the change amount is a negative value is It is and a second coefficient calculating means for calculating.

  In a preferred embodiment of the present invention, the information calculation means further comprises positive / negative discrimination means for discriminating whether the phase change amount received from each control circuit is a positive value or a negative value. The coefficient calculation means determines the ratio of the electrical information received from each control circuit to the total value of the electrical information received from each control circuit determined that the phase change amount is a positive value. First coefficient calculating means for calculating a coefficient based on each of the control information received from each control circuit for the total value of the electrical information received from each control circuit determined to have a negative value of the phase change amount Second coefficient calculation means for calculating a coefficient based on the ratio of the electrical information, and the phase change reference value calculation means is configured to determine the phase change amount determined to be a positive value. First phase change amount reference value calculating means for calculating the amount of change reference value, and second phase change amount reference value for calculating the phase change amount reference value of the phase change amount determined to be a negative value And a calculating means.

In a preferred embodiment of the present invention, a synchronous generator that supplies AC power is connected to the power system, and the coefficient calculating means is a power value P _{i of the} active power received from each control circuit. Based on (i = 1, 2,..., N), the coefficient K _i is calculated by the following equation.

ただし、Ｋ_iは複数の分散電源がｎ台ある場合のｉ番目の分散電源の制御回路に対応する係数であり、Ｚ_SおよびＥ_Gは前記同期発電機の同期インピーダンスおよび端子電圧である。

However, K _i is a coefficient corresponding to the control circuit of the i-th distributed power supply when there are n plural distributed power supplies, and Z _S and E _G are the synchronous impedance and terminal voltage of the synchronous generator.

The control circuit provided by the second aspect of the present invention includes an inverter circuit that converts direct current power into alternating current power, and includes a distributed power source that supplies the alternating current power to a power system, and performs PWM control on the inverter circuit. A phase change amount calculating means for detecting a phase of the power system and calculating a change amount of the detected phase; and an electric circuit for transmitting electrical information relating to the output of the distributed power source to the server. Based on information transmission means, calculation information corresponding to the output of each distributed power source calculated and transmitted based on the electrical information received by the server from a plurality of the control circuits, and the phase change amount , Command value signal generating means for generating a command value signal for commanding a voltage signal output from the inverter circuit, and a PWM signal for generating a PWM signal based on the command value signal Characterized in that it comprises a generation means.

  The distributed power supply provided by the third aspect of the present invention includes an inverter circuit and a control circuit provided by the second aspect of the present invention.

  According to the present invention, electrical information related to the output of each distributed power source is transmitted to the server, and the server calculates calculation information to be transmitted to each control circuit based on the electrical information. Each control circuit controls the AC power that each distributed power supply supplies to the power system based on the calculation information received from the server. Accordingly, each distributed power source is controlled by the AC power supplied to the power system according to its output. As a result, the burden of each distributed power source becomes equal to the output. Therefore, it is possible to equalize the loss of power generation opportunities of a plurality of distributed power sources linked to the power system. In addition, since the server controls each control circuit by calculating calculation information for controlling the output power of each distributed power source and transmitting it to each control circuit, the supply of power on the power system is excessive. It is possible to prevent the suppression or excessive suppression. Thereby, it can suppress that stability of an electric power grid | system is impaired.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is a block diagram for demonstrating 1st Embodiment of the control system which concerns on this invention. It is a block diagram for demonstrating the distributed power supply provided with the control circuit which comprises the control system which concerns on 1st Embodiment. It is a block diagram for demonstrating the control circuit which comprises the control system which concerns on 1st Embodiment. It is a block diagram for demonstrating the server which comprises the control system which concerns on 1st Embodiment. It is a block diagram for demonstrating the other Example of the control circuit which comprises the control system which concerns on 1st Embodiment. It is a block diagram for demonstrating 2nd Embodiment of the control system which concerns on this invention. It is a block diagram for demonstrating 3rd Embodiment of the control system which concerns on this invention. It is a block diagram for demonstrating 4th Embodiment of the control system which concerns on this invention. It is a block diagram for demonstrating 5th Embodiment of the control system which concerns on this invention. It is a block diagram for demonstrating the server which comprises the control system which concerns on 5th Embodiment.

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

FIG. 1 is a block diagram for explaining a first embodiment of a control system according to the present invention. In this embodiment, a case where _n distributed power sources A ₁ to An are connected to a power system B to which one synchronous generator C is connected will be described.

The control system includes a control circuit for controlling each of the respective inverter circuits of the distributed power supply A ₁ to A _n supplies (not shown) the power to the power grid B, and, the sending and receiving of information to and from these control circuits And a server D to perform. Each control circuit transmits the power value P _{i of} active power and the voltage phase change Δθ _i output from the distributed power source A _i (i = 1, 2,..., N) to the server D, and transmits from the server D. The received coefficient K _i is received. Each control circuit controls the active power output from the distributed power source A _i by controlling the inverter circuit based on the received coefficient K _i . Server D calculates the coefficient K ₁ ~K _n based on the amount of change Δθ ₁ ~Δθ _n of active power of the power value P ₁ to P _n and the voltage phase of the input from the control circuit, the distributed power A _i The coefficient K _i is transmitted to each control circuit.

FIG. 2 is a block diagram for explaining a distributed power source A including a control circuit constituting the control system according to the first embodiment. Configuration of each distributed power source A ₁ to A _n are the same as distributed power A.

  The distributed power source A includes a DC power source 1, an inverter circuit 2, a control circuit 3, a filter circuit 4, a transformer circuit 5, a current sensor 6, and a voltage sensor 7. The distributed power source A converts DC power generated by the DC power source 1 into AC power by the inverter circuit 2 and supplies the AC power to the power system B.

  The DC power source 1 generates DC power and includes a solar cell that converts sunlight energy into electrical energy. Note that the DC power source 1 is not limited to one that generates DC power from a solar cell. For example, the DC power source 1 may be a fuel cell, a storage battery, an electric double layer capacitor, or a lithium ion battery. Moreover, the apparatus which converts and outputs the alternating current power produced | generated by the diesel engine generator, the micro gas turbine generator, the wind turbine generator, etc. to direct current power may be sufficient.

  The inverter circuit 2 is a three-phase inverter, and is a PWM control type inverter circuit including three sets of six switching elements (not shown). The inverter circuit 2 converts the DC power input from the DC power source 1 into AC power by turning on and off each switching element based on the PWM signal input from the control circuit 3. Inverter circuit 2 is not limited to a three-phase inverter, and may be a single-phase inverter.

  The control circuit 3 generates a PWM signal for controlling the on / off operation of the switching element of the inverter circuit 2. The control circuit 3 receives the output current signal I from the current sensor 6, receives the output voltage signal V from the voltage sensor 7, receives the coefficient K from the server D, generates a PWM signal using these, and generates an inverter Output to circuit 2. In addition, the control circuit 3 calculates the power value P of the active power output from the distributed power source A and the voltage phase change amount Δθ, and transmits it to the server D. Details of the control circuit 3 will be described later.

  The filter circuit 4 is a low-pass filter including a reactor and a capacitor. The filter circuit 4 removes switching noise included in the AC voltage output from the inverter circuit 2. The transformer circuit 5 raises or lowers the AC voltage output from the filter circuit 4 to a level substantially equal to the system voltage.

  The current sensor 6 detects an alternating current output from the distributed power source A. The detected output current signal I is input to the control circuit 3. The voltage sensor 7 detects the voltage at the output terminal of the distributed power source A (that is, the system voltage at the interconnection point). The detected output voltage signal V is input to the control circuit 3.

  Next, details of the control circuit 3 will be described.

  FIG. 3 is a block diagram for explaining the control circuit 3. The control circuit 3 includes an active power calculator 31, a phase detector 32, a phase change calculator 33, a multiplier 34, a target corrector 35, a deviation calculator 36, an active power controller 37, a command value signal generator 38, In addition, a PWM signal generation unit 39 is provided.

  The active power calculation unit 31 calculates a power value (hereinafter referred to as “output active power value”) P of active power output from the distributed power source A. The active power calculator 31 calculates an output active power value P from the output current signal I input from the current sensor 6 and the output voltage signal V input from the voltage sensor 7, and outputs the output active power value P to the deviation calculator 36 and the server D. To do.

  The phase detection unit 32 is a so-called PLL circuit, and detects the phase θ of the output voltage signal V input from the voltage sensor 7 at a predetermined timing. The detection timing of the phase θ in each control circuit 3 is synchronized. The phase detection unit 32 outputs the detected phase θ to the phase change amount calculation unit 33.

  The phase change amount calculation unit 33 calculates the change amount Δθ of the phase θ input from the phase detection unit 32. The phase change amount calculation unit 33 calculates the phase change amount Δθ from the difference between the phase θ input this time and the phase θ input last time. Therefore, when the phase θ is advanced, the change amount Δθ is a positive value, and when the phase θ is delayed, the change amount Δθ is a negative value. The phase change amount calculation unit 33 outputs the calculated phase change amount Δθ to the multiplication unit 34 and the server D.

The multiplication unit 34 calculates a correction value (target value of synchronization power) P _S by multiplying the phase change amount Δθ input from the phase change amount calculation unit 33 by the coefficient K input from the server D. Output. Since the coefficient K input from the server D is a positive value, when the phase advances and the phase change amount Δθ becomes a positive value, the correction value P _S becomes a positive value, and the phase is delayed and the phase change amount Δθ. Is a negative value, the correction value P _S is a negative value.

The target correction unit 35 subtracts the correction value P _S input from the multiplication unit 34 from the target active power P ^* and outputs the result to the deviation calculation unit 36. In the present embodiment, the case where the synchronized power is supplied from the synchronous generator C to the distributed power source A is set in the positive direction (see FIG. 1), so the target correction unit 35 determines the correction value from the target active power P ^*. P _S is subtracted. That is, when the correction value P _S is a positive value, the target active power P ^* is corrected to decrease, and when the correction value P _S is a negative value, the target active power P ^* is corrected to increase. .

The deviation calculation unit 36 calculates a deviation ΔP between the output active power value P input from the active power calculation unit 31 and the corrected target active power (P ^* −P _S ) input from the target correction unit 35. Is. The calculated deviation ΔP is input to the active power control unit 37.

  The active power control unit 37 calculates a correction value for controlling the active power to be output based on the deviation ΔP input from the deviation calculation unit 36 and outputs the correction value to the command value signal generation unit 38.

  The command value signal generation unit 38 generates a command value signal for commanding a voltage signal output from the inverter circuit 2 based on the correction value input from the active power control unit 37.

  The PWM signal generation unit 39 generates a pulse signal with a dead time added based on the difference between the command value signal input from the command value signal generation unit 38 and a preset carrier signal. The PWM signal generation / generation unit 39 outputs the generated pulse signal to the inverter circuit 2 as a PWM signal. The method for generating the PWM signal is not limited to the case where the PWM signal is generated based on the difference between the command value signal and the carrier signal (for example, the triangular wave comparison method). For example, the PWM signal may be generated by so-called hysteresis control.

  The configuration of the control circuit 3 is not limited to that shown in FIG. The control circuit 3 controls the effective power output from the inverter circuit 2 so as to synchronize the voltage phase with another power supply source such as a synchronous generator C connected to the power system B. I just need it.

  Next, the operation of the distributed power source A will be described.

  The inverter circuit 2 (see FIG. 2) converts DC power output from the DC power supply 1 into AC power. The filter circuit 4 removes switching noise of the AC voltage output from the inverter circuit 2. The transformer circuit 5 transforms the AC voltage output from the filter circuit 4 and supplies it to the power system B. The control circuit 3 generates a PWM signal for controlling the output active power and outputs the PWM signal to the inverter circuit 2.

When the voltage phase θ at the interconnection point of the distributed power source A is advanced, the phase change amount Δθ calculated by the phase change amount calculation unit 33 is a positive value, and the target active power P ^* is decreased by the correction value P _S. To be corrected. Therefore, control is performed so that the output active power of the distributed power source A decreases. Thereby, the synchronized electric power is supplied from the synchronous generator C to the distributed power source A, and the phase is adjusted by delaying the phase of the synchronous generator C. On the other hand, when the voltage phase θ is delayed, the phase change amount Δθ calculated by the phase change amount calculation unit 33 is a negative value, and the target active power P ^* increases by the correction value P _S (<0). To be corrected. Therefore, control is performed so that the output active power of the distributed power source A increases. As a result, the synchronized power is supplied from the distributed power source A to the synchronous generator C, and the phase of the synchronous generator C is advanced to adjust the phase. In other words, the distributed power source A has a synchronizing power similar to the synchronous generator C.

  Further, when the phase change amount is differentiated with respect to time, the frequency change amount is obtained, and when the frequency change amount is integrated with time, the phase change amount is obtained. Accordingly, since the phase change amount and the frequency change amount have a correspondence relationship, the frequency control can be performed by controlling the output active power according to the phase change amount.

For example, when the demand for active power in the power system B increases due to fluctuations in the connected load, the voltage phase θ at the interconnection point of the distributed power source A is delayed. Therefore, the phase change amount Δθ calculated by the phase change amount calculation unit 33 is a negative value, and the target active power P ^* is corrected so as to increase by a value proportional to the magnitude of the phase change amount Δθ. Therefore, control is performed so that the output active power of the distributed power source A increases. Conversely, when the demand for active power in the power system B decreases, the voltage phase θ at the interconnection point of the distributed power source A advances. Therefore, the phase change amount Δθ calculated by the phase change amount calculation unit 33 is a positive value, and the target active power P ^* is corrected so as to decrease by a value proportional to the phase change amount Δθ. Therefore, control is performed so that the output active power of the distributed power source A decreases. Thereby, since the power supply-demand balance is maintained, the system frequency of the power system B is kept stable. That is, the distributed power source A can perform frequency control in the same manner as the synchronous generator C.

  Next, details of the server D will be described.

Server D is the coefficient K ₁ based on the respective dispersed generator A ₁ to A _n output effective power inputted from the control circuit of the value P ₁ to P _n and the phase variation Δθ ₁ ~Δθ _n, and transmits to the control circuit to calculate the ~K _n. In this embodiment, as the burden of synchronizing power for transferring between the synchronous generator C is evenly distributed supply A ₁ to A _n being interconnection, the coefficients K ₁ ~K _n Calculated.

  FIG. 4 is a block diagram for explaining the server D. As shown in FIG. The server D includes a receiving unit D1, a calculating unit D2, and a transmitting unit D3.

Receiving unit D1 are those receives each distributed power A ₁ to A _n output active power value P ₁ to P _n and the phase variation Δθ ₁ ~Δθ _n transmitted from the control circuit, and outputs the calculation unit D2 It is. Calculator D2, based on the output effective power value P ₁ to P _n and the phase variation Δθ ₁ ~Δθ _n inputted from the receiving unit D1, calculates the coefficient K ₁ ~K _n by a predetermined calculation formula, This is output to the transmission unit D3. The predetermined calculation formula will be described later. Transmission unit D3 is the coefficient K ₁ ~K _n inputted from the calculating portion D2, is to send to the control circuits of the corresponding distributed power A ₁ to A _n.

Uniformly enter the synchronous generator C synchronized power P _SG outputted from the synchronous generator C to the voltage when the phase advances (see FIG. 1) in each distributed power source A ₁ to A _n, of the synchronous generator C so that each distributed power source a ₁ to a _n synchronized power P _SG is input to the synchronous generator C when the voltage phase delayed outputs equally, to calculate the coefficient K ₁ ~K _n.

Synchronizing power P _SG output from the alternator C at any time, [Delta] [theta] a variation of the voltage phase, the synchronous impedance Z _S of the synchronous generator C, when the inter-terminal voltage is E _G, the following (1 ) Expression.

Be controlled so as to synchronize power P _SG outputted from the synchronous generator C and inputs the distributed each distributed power source A ₁ to A _n, it is possible to synchronize the phase. Therefore, _assuming that the synchronized powers input to the distributed power sources A _{1 to} An at the above timing are P _{S1 to} P _Sn , the synchronized powers P _{S1 to} P _Sn are controlled so as to satisfy the following equation (2). do it.

Further, in order to equalize the load on each distributed power source A ₁ to A _n, in the present embodiment, so as to bear the synchronization power according to the active power each distributed power source A ₁ to A _n outputs. That is, the control is performed so that the synchronized powers P _{S1 to} P _Sn inputted to the distributed power sources A ₁ to An are _expressed by the following equation (3).

From the above equations (1) and (3), the following equation (4) is derived. Further, since the amount of change Δθ in the voltage phase when inputting / outputting the synchronization power is extremely small, it can be considered that SINΔθ≈Δθ. Therefore, the synchronized power P _Si (i = 1, 2,..., N) to be input to the distributed power source A _i (i = 1, 2,..., N) can be expressed by the following equation (5).

In the server D, advance recorded synchronous impedance Z _S and the voltage between the terminals E _G of the synchronous generator C, and receives the output effective power value P ₁ to P _n from the control circuit of each distributed power source A ₁ to A _n Thus, the coefficients K _{1 to} K _n can be calculated. The server D transmits the calculated coefficients K _{1 to} K _n to the control circuits of the respective distributed power sources A _{1 to An} , and the control circuit of each distributed power source A _i (i = 1, 2,..., N) has a coefficient K. _The synchronization power P _Si to be input is calculated from _i and the phase change amount Δθ _i . By the calculated synchronized power P _Si as the corrected value P _S for adjusting the target effective power P ^*, it is possible to superimpose the synchronizing power to enable power output from each distributed power source A ₁ to A _n.

In the present embodiment, the output effective power value P ₁ to P _n of the distributed power supply A ₁ to A _n from the control circuit is transmitted to the server D, the coefficient K ₁ ~K _n is calculated by the server D. The calculated coefficients K _{1 to} K _n are transmitted to the corresponding control circuits. The control circuit of each distributed power source A _i corrects the target active power P ^* based on the received coefficient K _i . Each coefficient K ₁ ~K _n is calculated in accordance with the output effective power value P ₁ to P _n of the dispersed generator A ₁ to A _n. Accordingly, the ratios of the synchronized powers P _{S1 to} P _Sn borne by the distributed power sources A _{1 to An} to the output active power values P _{1 to} P _n are equal. Therefore, it is possible to equalize the loss of power generation opportunities each distributed power source A ₁ to A _n. The total synchronizing power P _S1 to P _Sn of each distributed power source A ₁ to A _n are borne, so consistent with synchronized power P _SG of the synchronous generator C, and the power supply on the power system B over Or excessive suppression can be suppressed. Thereby, it can suppress that stability of the electric power grid | system B is impaired.

In the first embodiment, the equation for calculating the coefficient K _{i is} the equation shown in the proviso of the equation (5), but is not limited thereto. For example, the synchronization power may be borne according to the square value of the output active power value P _i . Further, the coefficient K _i may be calculated by the following equation (6), where x is a real number. Further, the coefficient K _i may be calculated according to other electrical information such as output active current, output reactive power, and output apparent power. In this case, the corresponding electrical information may be detected by each control circuit and transmitted to the server D.

In the first embodiment, the case where the phase change amount Δθ _i is also transmitted from each control circuit to the server D is described. However, since the phase change amount Δθ _i is not used to calculate the coefficient K _i (see above). (See the proviso in equation (5)), but the phase change amount Δθ _i may not be transmitted.

Although the case where the control circuit 3 controls the output active power has been described in the first embodiment, the present invention is not limited to this. For example, the output effective current may be controlled. In this case, the control circuit may be configured as a control circuit 3 ′ shown in FIG. That is, the correction value (target value of the synchronization current) _Is is calculated by multiplying the phase change amount Δθ output from the phase change amount calculation unit 33 by the coefficient K ′ input from the server D, and the target effective current is calculated. Correct I _P ^* . The effective current control unit 37 ′ outputs a correction value based on the deviation ΔI _P between the effective current I _P calculated by the effective current calculation unit 31 ′ and the corrected target effective current (I _P ^* −I _S ). The server D may calculate the coefficient K ′ based on the effective current I _P input from the control circuit 3 ′.

In the first embodiment, the case where the server D outputs the coefficient K _i (i = 1, 2,..., N) to the control circuit of each distributed power source A _i has been described, but the present invention is not limited to this. For example, the server D may calculate the synchronization power P _Si from the coefficient K _i and the phase change amount Δθ _i and output them to each control circuit.

FIG. 6 is a block diagram for explaining a second embodiment of the control system according to the present invention. In the figure, the same or similar elements as those in the first embodiment (see FIG. 1) are denoted by the same reference numerals. The control system according to the second embodiment is different from the first embodiment in that the server D transmits the synchronization power P _Si instead of the coefficient K _i . The server D calculates the synchronization power P _Si by multiplying each calculated coefficient K _i by the phase change amount Δθ _i received from the control circuit of each distributed power source A _i , and transmits it to each control circuit. . Each control circuit inputs the received synchronization power P _Si as a correction value P _S to the target correction unit 35 (see FIG. 3). Even in this case, the same effect as the first embodiment can be obtained.

Alternatively, the server D may calculate the average value (or median value) of the phase change amounts Δθ _i received from the control circuits of the respective distributed power sources A _i and output the average values to the respective control circuits.

FIG. 7 is a block diagram for explaining a third embodiment of the control system according to the present invention. In the figure, the same or similar elements as those in the first embodiment (see FIG. 1) are denoted by the same reference numerals. The control system according to the third embodiment is different from the first embodiment in that the server D transmits an average value (or median value) Δθ ′ of the phase change amount Δθ _i in addition to the coefficient K _i . The server D calculates the average value (or median value) Δθ ′ of the phase variation Δθ _i received from the control circuit of each distributed power source A _i , and calculates the average value (or median value) Δθ ′ and the coefficient K. _i is transmitted to each control circuit. Each control circuit calculates the synchronization power P _Si ′ by multiplying the received average value (or median value) Δθ ′ and the coefficient K _i, and the target correction unit 35 (see FIG. 3) as the correction value P _S. ). Even in this case, the same effect as the first embodiment can be obtained. The average value of the phase change amount [Delta] [theta] _i (or median) Since use of the [Delta] [theta] ', even if the phase change amount [Delta] [theta] _i detected by the control circuits contained the error, the output of each distributed power source A _i The active power can be appropriately controlled.

Alternatively, the server D may calculate the synchronization power P _Si ′ from the coefficient K _i and the average value (or median value) Δθ ′ and output it to each control circuit.

FIG. 8 is a block diagram for explaining a fourth embodiment of the control system according to the present invention. In the figure, the same or similar elements as those in the first embodiment (see FIG. 1) are denoted by the same reference numerals. The control system according to the fourth embodiment is different from the first embodiment in that the server D transmits the synchronization power P _Si ′ instead of the coefficient K _i . The server D calculates the average value (or median value) Δθ ′ of the phase variation Δθ _i received from the control circuit of each distributed power source A _i , and calculates the calculated coefficient K _i and the average value (or median value). ) Multiplying by Δθ ′, the synchronization power P _Si ′ is calculated and transmitted to each control circuit. Each control circuit inputs the received synchronization power P _Si ′ as a correction value P _S to the target correction unit 35 (see FIG. 3). Even in this case, the same effect as the third embodiment can be obtained.

The average value in the third and fourth embodiments (or median) in calculating [Delta] [theta] ', and detect the amount of change in the voltage phase other than the interconnection point of the dispersed generator A ₁ to A _n and the server It may be transmitted to D and calculated using these as well. In this case, since the number of populations increases, the average value (or median value) Δθ ′ can be calculated with higher accuracy.

In the first to fourth embodiments, the case where only one synchronous generator C is connected to the power system B has been described. When a plurality of synchronous generators are connected to the electric power system B, the phase change amount may be different depending on each synchronous generator. The phase change amount Δθ _i detected by the distributed power source A _i is the phase change amount of the closest synchronous generator. Therefore, the phase change amount Δθ _i detected by each distributed power source A _i may differ greatly. When the phase change amounts of all the synchronous generators are positive values, the synchronous power is supplied from each synchronous generator to each distributed power source A _i, and the phase change amounts of all the synchronous generators are negative values. In this case, it is only necessary to supply the synchronized power from each distributed power source A _i to each synchronous generator, and it is only necessary that each distributed power source A _i bears the synchronized power corresponding to the output active power value P _i. The method described above can be applied. However, since the synchronization force acts between the synchronous generators, the phase change amount of one synchronous generator is a positive value and the phase change amount of the other synchronous generator is a negative value. To do. In this case, depending on the distributed power supply A _i , there are a power to be output and a power to be input. That is, the distributed power source A _i close to the synchronous generator having a positive phase change amount should be input with the synchronized power, and the distributed power source A _i close to the synchronous generator having a negative phase change amount. Should output synchronized power. In this case, the appropriate synchronized power cannot be calculated even using the above equation (5) using the total value of the output active power values P _i of all the distributed power sources A _i . In this case, it is necessary to separately calculate the synchronized power separately for the distributed power source A _i where the detected phase change amount Δθ _i is positive and the distributed power source A _{i where} it is negative. The case where a some synchronous generator is connected to the electric power grid | system B as 5th Embodiment below is demonstrated.

FIG. 9 is a block diagram for explaining a fifth embodiment of the control system according to the present invention. In the figure, the same or similar elements as those in the first embodiment (see FIG. 1) are denoted by the same reference numerals. In the fifth embodiment, a case where _n distributed power sources A ₁ to An are connected to a power system B to which _two synchronous generators C ₁ and C ₂ are connected will be described.

In the control system according to the fifth embodiment, the server D ′ divides the distributed power sources A _{1 to An} into two groups (that is, the detected phase change amount Δθ _i is positive and the negative group). Thus, the present embodiment is different from the first embodiment in that the coefficient is calculated based on the output active power value P _i input from the control circuit of the distributed power source A _i belonging to each group.

  FIG. 10 is a block diagram for explaining the server D ′. In the figure, the same or similar elements as those in the first embodiment (see FIG. 4) are denoted by the same reference numerals. The server D ′ has a receiving unit D1 provided with a comparison unit D11 and a selection unit D12, and a calculation unit D2 provided with a phase advance group calculation unit D21 and a phase delay group calculation unit D22. Thus, it is different from the server D of the first embodiment.

The comparison unit D11 determines whether the phase change amount Δθ _i received from the control circuit of each distributed power source A _i is a positive value or a negative value, and outputs the determination result to the selection unit D12. To do. This determination is made based on whether or not the phase change amount Δθ _i is equal to or greater than zero. The determination may be made based on whether or not the phase change amount Δθ _i is equal to or less than zero.

Based on the determination result input from the comparison unit D11, the selection unit D12 uses the phase advance group calculation unit D21 or the phase delay group calculation unit D22 as the output active power value P _i received from the control circuit of each distributed power source A _i. Is output. When the phase change amount Δθ _i is a positive value (ie, when the phase is advanced), the selection unit D12 outputs the color output active power value P _i to the phase advance group calculation unit D21, and the phase change amount Δθ _i is When it is a negative value (that is, when the phase is delayed), the output active power value P _i is output to the phase delay group calculation unit D22.

The phase advance group calculation unit D21 calculates a coefficient K _i by a predetermined calculation formula based on the output active power value P _i input from the selection unit D12, and transmits the calculated coefficient K _i to the transmission unit D3. Output to. The phase advance group calculation unit D21 calculates the coefficient K _i only from the output active power value P _i of the distributed power source A _i whose phase change amount Δθ _i is a positive value. The phase delay group calculation unit D22 calculates a coefficient K _i by a predetermined calculation formula based on the output active power value P _i input from the selection unit D12, and the calculated coefficient K _i is transmitted to the transmission unit D3. Output to. The phase delay group calculation unit D22 calculates the coefficient K _i only from the output active power value P _i of the distributed power source A _i whose phase change amount Δθ _i is a negative value. Thereby, the distributed power sources A _{1 to An} are divided into a group in which the phase change amount Δθ _i is positive and a group in which the phase change amount Δθ _i is positive, and the coefficient K _i is calculated separately.

Hereinafter, calculation formulas used in the phase advance group calculation unit D21 and the phase delay group calculation unit D22 will be described. In addition, as shown in FIG. 9, the case where the phase of the synchronous generator C ₁ is advanced and the phase of the synchronous generator C ₂ is delayed will be described as an example. Since the distributed power sources A _{1 to} A _j (1 ≦ j <n) are connected near the synchronous generator C ₁ , the phase change amounts Δθ _{1 to} Δθ _j are positive values, and the distributed power sources A _{j Since +1 to An} are connected in the vicinity of the synchronous generator C ₂ , the phase change amounts Δθ _{j + 1 to} Δθ _n are negative values.

The synchronization power output from the synchronous generator C _{1 at an} arbitrary timing is P _SG1 , the voltage phase change amount is Δθ _G1 , the synchronous impedance of the synchronous generator C ₁ is Z _S1 , and the voltage between terminals is E _G1. Assuming that the active power values received from the control circuits of the power sources A _{1 to} A _j are P _{1 to} P _j , respectively, the distributed power sources A _i (i = 1, 2,. synchronization power P _Si to be input can be expressed by the following equation (7) in). Note that the case where the synchronized power is supplied from the synchronous generator C ₁ to the distributed power sources A _{1 to} A _j is defined as a positive direction.

Similarly, the synchronous power input to the synchronous generator C ₂ at an arbitrary timing is P _SG2 , the voltage phase change amount is Δθ _G2 , the synchronous impedance of the synchronous generator C ₂ is Z _S2 , and the voltage between terminals is E _G2. and then, dispersed power source a _j + 1 If to a _n of the control circuit power values of active power received from each and P _j + 1 ~P _n, distributed power _{a i (i = j + 1} , j + 2, ~, n) from The output synchronization power P _Si can be expressed by the following equation (8). Note that the case where the synchronized power is supplied from the distributed power sources A _{j + 1 to An} to the synchronous generator C ₂ is defined as a positive direction.

In the server D ', synchronous generator C ₁ and C ₂ of the synchronous impedance Z _S1 and Z _S2, recorded beforehand voltage E _G1 and E _G2 between the terminals, an output from the control circuit of each distributed power source A ₁ to A _n The coefficients K _{1 to} K _n can be calculated by receiving the effective power values P _{1 to} P _n and the phase change amounts Δθ _{1 to} Δθ _n . The server D ′ transmits the calculated coefficients K _{1 to} K _n to the control circuits of the respective distributed power sources A _{1 to An} , and the control circuits of the respective distributed power supplies A _i (i = 1, 2,..., N) The synchronization power P _Si is calculated from K _i and the phase change amount Δθ _i . By the calculated synchronized power P _Si as the corrected value P _S for adjusting the target effective power P ^*, it is possible to superimpose the synchronizing power to enable power output from each distributed power source A ₁ to A _n. Even in this case, the same effect as the first embodiment can be obtained.

For the case where three or more synchronous generator is connected to the power system B also divide the distributed power A ₁ to A _n into groups, a group and a negative is positive phase change amount [Delta] [theta] _i, each group The coefficient K _i can be calculated based on the output active power value P _i input from the control circuit of the distributed power source A _i to which it belongs. In this case, the synchronous impedances Z _S1 and Z _S2 and the inter-terminal voltages E _G1 and E _G2 in the above equations (7) and (8) are common to the entire system using a non-dimensional method (unit method). The value calculated as the value to be used is used. Even when two synchronous generators C ₁ and C ₂ are connected to the electric power system B described above, the values calculated as common values for the entire system may be used as well. Good.

The fifth embodiment may be combined with the second to fourth embodiments. That is, as in the second embodiment, the server D ′ multiplies the coefficient K _i and the phase change amount Δθ _i to calculate the synchronization power P _Si and transmits it to each control circuit, which is received by each control circuit. The synchronized power P _Si may be input to the target correction unit 35 (see FIG. 3) as the correction value P _S. Further, as in the third embodiment, the server D ′ calculates the average value (or median value) Δθ ′ of the phase change amount Δθ _i and transmits it to the respective control circuits together with the coefficient K _i , and each control circuit receives it. The synchronized power P _Si ′ may be calculated by multiplying the average value (or median value) Δθ ′ and the coefficient K _i and input to the target correction unit 35 as the correction value P _S. The average value (or median value) Δθ ′ is also an average value (or median value) of phase change amounts Δθ _i that are positive values and an average value (or median value) of phase change amounts Δθ _i that are negative values (or values). , Median) need to be calculated separately. Also, calculated as the fourth embodiment, the server D 'is the average value of the phase change amount [Delta] [theta] _i (or median) [Delta] [theta]' synchronization power P _Si 'by multiplying the coefficient K _i was calculated Then, the synchronization power P _Si ′ transmitted to each control circuit and received by each control circuit may be input to the target correction unit 35 as the correction value P _S. Again, the average value (or median) as [Delta] [theta] ', the average value of a positive value phase change amount [Delta] [theta] _i (or median) and the phase change amount [Delta] [theta] the average value of _i is a negative value (Or median) must be calculated separately.

  The control system according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the control system according to the present invention can be modified in various ways.

A, A _{1 to An} distributed power source 1 DC power source 2 Inverter circuit 3, 3 ′ Control circuit 31 Active power calculation unit (electrical information transmission means)
31 'Effective current calculation part (electrical information transmission means)
32 phase detector 33 phase change amount calculator 34 multiplier (correction value calculator)
35 Target Correction Unit 36 Deviation Calculation Unit 37 Active Power Control Unit 37 ′ Active Current Control Unit 38 Command Value Signal Generation Unit 39 PWM Signal Generation Unit 4 Filter Circuit 5 Transformer Circuit 6 Current Sensor 7 Voltage Sensor B Power System C, C ₁ , C ₂ synchronous generator D, D 'server D1 receiver D11 comparison unit (positive / negative discrimination means)
D12 selection unit D2 calculation unit (information calculation means, coefficient calculation means)
D21 Phase advance group calculation unit (first coefficient calculation means)
D22 Phase delay group calculation unit (second coefficient calculation means)
D3 transmitting unit (information transmitting means)

Claims (13)

A control circuit for PWM-controlling the inverter circuit, each of the control circuits provided in each of a plurality of distributed power supplies having an inverter circuit for converting DC power into AC power and supplying the AC power to a power system; A control system including a server that transmits and receives information between them,
Each of the control circuits is
A phase change amount calculating means for detecting the phase of the power system and calculating a change amount of the detected phase;
Electrical information transmitting means for transmitting electrical information related to the output of the distributed power source to the server;
Command value signal generating means for generating a command value signal for commanding a voltage signal output from the inverter circuit based on the calculation information received from the server and the phase change amount ;
PWM signal generating means for generating a PWM signal based on the command value signal;
Equipped with a,
Before SL server,
Information calculating means for calculating the calculation information corresponding to the output of each distributed power source based on the electrical information received from each control circuit;
Information transmitting means for transmitting each of the calculated information calculated by the information calculating means to each of the corresponding control circuits;
With
A control system characterized by that. The information calculating means includes
Coefficient calculation means for calculating a coefficient based on the ratio of the electrical information to the total value of the electrical information received from each control circuit.
The control system according to claim 1. Each of the control circuits further comprises an active power calculation means for calculating a power value of active power output from the distributed power source,
The electrical information transmitting means transmits the power value calculated by the active power calculating means as the electrical information;
The control system according to claim 2. Wherein each of the control circuits of the previous SL on the basis of the phase change amount and the correction value calculated from the coefficients, further comprising a target correction means to correct the target value of the output active power,
The said command value signal generation means produces | generates the command value signal for making the electric power value calculated by the said active power calculation means correspond with the correction target value corrected by the said target correction means. Control system. The information transmitting means transmits the coefficients calculated by the coefficient calculating means to the corresponding control circuits as the calculated information, respectively.
Each of the control circuits further includes a correction value calculation unit that calculates the correction value by multiplying the phase change amount calculated by the phase change amount calculation unit by a coefficient received from the server.
The control system according to claim 4. Each control circuit further includes phase change amount transmitting means for transmitting the phase change amount calculated by the phase change amount calculating means to the server,
The information calculation means includes correction value calculation means for calculating the correction values by multiplying the coefficients calculated by the coefficient calculation means by the phase change amounts received from the corresponding control circuits. In addition,
The information transmission means transmits the correction value calculated by the correction value calculation means to the corresponding control circuits as the respective calculation information.
The control system according to claim 4. Each of the control circuits is
Phase change amount transmitting means for transmitting the phase change amount calculated by the phase change amount calculating means to the server;
Correction value calculation means for calculating the correction value from the calculation information received from the server,
The information calculation means further comprises phase change amount reference value calculation means for calculating a phase change amount reference value that is an average value or a median value of the phase change amounts received from the respective control circuits,
The information transmission means corresponds to the coefficients calculated by the coefficient calculation means and the phase change amount reference values calculated by the phase change reference value calculation means as the calculation information, respectively. Sent to each control circuit,
The correction value calculation means calculates the correction value by multiplying the coefficient received from the server and the phase change amount reference value.
The control system according to claim 4. Each control circuit further includes phase change amount transmitting means for transmitting the phase change amount calculated by the phase change amount calculating means to the server,
The information calculating means includes
A phase change amount reference value calculating means for calculating a phase change amount reference value that is an average value or a median value of the phase change amounts received from the respective control circuits;
Correction value calculation means for multiplying each coefficient calculated by the coefficient calculation means by the phase change amount reference value calculated by the phase change reference value calculation means to calculate the correction value, respectively;
Further comprising
The information transmission means transmits the correction value calculated by the correction value calculation means as the calculation information to each of the corresponding control circuits.
The control system according to claim 4. Each of the control circuits includes phase change amount transmitting means for transmitting the phase change amount calculated by the phase change amount calculating means to the server,
The information calculating means further comprises positive / negative determining means for determining whether the phase change amount received from each control circuit is a positive value or a negative value, respectively.
The coefficient calculating means includes
A coefficient based on a ratio of the electrical information received from each control circuit to a total value of the electrical information received from each control circuit determined that the phase change amount is a positive value is calculated. A coefficient calculation means of 1;
A coefficient based on a ratio of the electrical information received from each control circuit to a total value of the electrical information received from each control circuit determined that the phase change amount is a negative value is calculated. 2 coefficient calculation means;
With
The control system according to claim 5 or 6. The information calculating means further comprises positive / negative determining means for determining whether the phase change amount received from each control circuit is a positive value or a negative value, respectively.
The coefficient calculating means includes
A coefficient based on a ratio of the electrical information received from each control circuit to a total value of the electrical information received from each control circuit determined that the phase change amount is a positive value is calculated. A coefficient calculation means of 1;
A coefficient based on a ratio of the electrical information received from each control circuit to a total value of the electrical information received from each control circuit determined that the phase change amount is a negative value is calculated. 2 coefficient calculation means;
With
The phase change amount reference value calculation means includes:
First phase change amount reference value calculating means for calculating the phase change amount reference value of the phase change amount determined to be a positive value;
A second phase change amount reference value calculating means for calculating the phase change amount reference value of the phase change amount determined to be a negative value;
With
The control system according to claim 7 or 8. A synchronous generator for supplying AC power is connected to the power system,
The coefficient calculation means is a power value P _i (i = 1) of the active power received from each control circuit.
, 2, ..., n), the coefficient K _i is calculated by the following equation:
The control system according to claim 3.

However, K _i is a coefficient corresponding to the control circuit of the i-th distributed power supply when there are n plural distributed power supplies, and Z _S and E _G are the synchronous impedance and terminal voltage of the synchronous generator. A control circuit for PWM control of the inverter circuit, which is provided in a distributed power source having an inverter circuit for converting DC power into AC power and supplying the AC power to a power system,
A phase change amount calculating means for detecting the phase of the power system and calculating a change amount of the detected phase;
Electrical information transmission means for transmitting the electrical information about the output of the distributed power supply to servers,
Based on the calculation information corresponding to the output of each of the distributed power sources calculated and transmitted based on the electrical information received by the server from the plurality of control circuits, and the phase change amount , the inverter circuit outputs Command value signal generating means for generating a command value signal for commanding a voltage signal to be transmitted;
PWM signal generating means for generating a PWM signal based on the command value signal;
A control circuit comprising: A distributed power supply comprising an inverter circuit and the control circuit according to claim 12 .

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