JP4365332B2 - Single operation detector for power generation facilities - Google Patents

Description

The present invention operates a power generation facility including, for example, a personal synchronous generator or a grid interconnection inverter in a commercial AC power system, and reversely flows power from the power generation facility to the commercial AC power system side. about alone operation detecting device and a power generator power plant which can be

  A power generation facility, which is a distributed power source installed in a consumer, is always connected to a commercial AC power system and operated in a grid connection.

  In this specification, isolated operation means the power connected to this power distribution system even though the power distribution system to which these power generation facilities are connected is disconnected from the commercial AC power system for some reason. The state where the electric power supply by the said power distribution equipment is continued with respect to load is said.

  When such an isolated operation occurs, the isolated operation state must be detected, and the power generation facility must be disconnected or stopped, otherwise, power from the commercial AC power system is supplied again. When this happens, there is a possibility of matching in an asynchronous state.

  In a certain prior art (Patent Document 1), when a single power generation facility is introduced to a consumer, a fluctuation signal is injected into the power generation facility to detect a single operation, and the commercial AC power system is disconnected. It is possible to detect a change in an electrical phenomenon that appears depending on the presence or absence and to reliably detect an isolated operation. If this conventional technology is implemented even when a plurality of power generation facilities are introduced to a consumer, this conventional technology does not synchronize the variation signal for each power generation facility. There is concern that the accompanying electrical phenomena may cancel each other and interfere with each other.

  Another prior art (Patent Document 2) for solving this problem is shown in a simplified manner in FIG. In FIG. 10, power generation is started in step a <b> 1, and the single operation detection function is operated for all the machines in the plurality of power generation facilities in step a <b> 2. At this time, in step a3, synchronization regarding the isolated operation detection function of each power generation facility is taken, and in step a4 and subsequent steps, the isolated operation detection function taking such synchronization is continued. In this prior art, fluctuation signals are synchronized using a distribution line.

  In the other conventional technology (Patent Document 3), the fluctuation signal is synchronized by the time information by the global positioning system (GPS). In the other conventional technology (Patent Document 4), Fluctuation signals are given in parallel to synchronize them, and in another prior art (Patent Document 5), the signal lines are connected to synchronize the fluctuation signals.

  As described above, when a plurality of power generation facilities are introduced into a consumer, in each of the other conventional techniques described above, the fluctuation signals are synchronized on the premise that an independent operation detection function for each power generation facility is used in combination. The islanding operation detection method is roughly classified into an active method and a passive method based on the detection principle, and there are various methods. In the above-described conventional techniques, when a power generation facility having a function of detecting an isolated operation in the same type is introduced, the fluctuation signals can be reliably synchronized. On the other hand, the problems of these conventional techniques make it difficult to synchronize the fluctuation signals when the method for achieving the isolated operation detection function is different for each of the plurality of power generation facilities.

  Further, in these conventional techniques, for all of the plurality of power generation facilities, for example, a fluctuation signal is superimposed on a distribution line, etc., and as a result, a redundant fluctuation signal may be injected for detecting an isolated operation. In view of the influence on the commercial AC power system, it is not preferable.

JP 7-311197 A JP-A-9-9510 JP-A-9-74684 JP 10-14294 A JP-A-10-94174

The object of the present invention is to prevent mutual interference of electrical phenomena that occur for the independent operation detection of a plurality of power generation facilities even in different types of systems with different principles for detecting an isolated operation, and further, to provide a islanding detection DeSo location and power generation equipment of the power generation facility so as to eliminate the redundancy operation.

The present invention includes a plurality of power generation facilities, each power generation facility,
Power generation means for connecting the generated power to a commercial AC power system, receiving a fluctuation signal, and changing the generated power;
A single operation detection means for generating a fluctuation signal and supplying it to the power generation means, and detecting a single operation according to the state of fluctuation of the generated power;
Representative machine selection means for selecting one of the operating power generation facilities as the representative machine,
An operation instruction means for operating the isolated operation detecting means when selected as the representative machine by the representative machine selecting means, and stopping the isolated operation detecting means when not selected as the representative machine ;
Counting means for counting at least one of the number of units in operation and the output capacity,
The isolated operation detection means is generated by determining the value of the fluctuation signal based on the number of operating units and the output capacity counted by the counting means when selected as the representative machine by the representative machine selection means. It is a single operation detection device for equipment.

  According to the present invention, instead of synchronizing the fluctuation signals as in the prior art described above, one of the plurality of operating power generation facilities is automatically selected as a representative machine, and Only the operation detection function is enabled, and the independent operation function of the power generation equipment of other machines excluding the representative machine is stopped. As a result, multiple power generation facilities are operated in parallel, and even if the principle of detecting isolated operation in these power generation facilities is a heterogeneous system, mutual interference of electrical phenomena that occurs to detect isolated operation is prevented. Independent operation detection is reliably achieved. Further, configuration and operation redundancy are eliminated.

Since single operation is detected in the single power generation facility selected as the representative unit for the multiple power generation facilities in operation, the value of the fluctuation signal is calculated from the number of power generation facilities in operation. Or depending on the total output capacity by their operating power generation facilities, the value of the fluctuation signal, for example a value such as the voltage or current amplitude of the fluctuation signal, is set variably. As a result, even if the number of units in operation and the output capacity of the plurality of power generation facilities change, it is possible to reliably detect an isolated operation.

In the present invention, the output capacity of each power generation facility is equal,
When counting the number of power generation facilities in operation,
The fluctuation signal value B generated by the isolated operation detecting means is B1, the fluctuation signal value of the single power generation facility is B1, the counted number of operating power generation facilities is N, and A is a predetermined value. When 0 <A ≦ 1,
B = B1, N, A
It is characterized by setting to.

In the present invention, when the counting means counts the total output capacity of the operating power generation equipment and the output capacity of the representative machine,
The value B of the fluctuation signal generated by the isolated operation detecting means is set to Bi as the value of the fluctuation signal of the representative machine, and the total output capacity of the counted power generation facilities in operation is set to ΣP, the output capacity Pi of the representative machine, When A is a predetermined value and 0 <A ≦ 1,
B = Bi · (ΣP / Pi) · A
It is characterized by setting to.

  In the present invention, the operating status of other power generation facilities is exchanged by communication, and the output of the fluctuation signal to the representative machine is changed according to the number of operating power generation facilities or the output capacity. For example, a plurality of power generation facilities have the same configuration or the same output capacity, and the value of the fluctuation signal used for detecting single operation in a single power generation facility is B1, and the number of operating power generation facilities is N The value B of the fluctuation signal is a value obtained by multiplying a predetermined value A and is set to B = B1 · N · A. Also, for example, when the value of the fluctuation signal used to detect isolated operation in the representative machine is Bi, the output capacity of this power generation equipment is Pi, and the total output capacity of the operating power generation equipment is ΣP, the fluctuation The signal value B is a value obtained by multiplying a predetermined value A, and is set to B = Bi · (ΣP / Pi) · A. The predetermined value A can be referred to as an output coefficient, is a value that exceeds zero and is 1 or less, and may be set to a value such as 0.6 or 0.8, for example. In order to detect islanding, it is only necessary to detect the fluctuation of the electric phenomenon that occurs, for example, the fluctuation of the output voltage separately from the load fluctuation, so the value of the output coefficient A decreases as the number of operating units increases. Or the value of the output coefficient A is decreased with an increase in the total output capacity of the operating power generation equipment.

In the present invention, the isolated operation detecting means
Including an inverter that converts DC power into AC power and flows back into the commercial AC power system,
This inverter is characterized in that the generated electric power is changed by a fluctuation signal and outputted.

In the present invention, the power generation means includes a synchronous generator,
Including an automatic voltage regulator for adjusting the field current of the synchronous generator,
The isolated operation detecting means changes the reactive power by supplying a fluctuation signal to the automatic voltage regulator.

  According to the present invention, the detection principle method for detecting the independent operation of each power generation facility is, for example, as an active method, for example: (1) Periodic reactive power fluctuation is given to the power generation output and Reactive power fluctuation method that detects periodic voltage fluctuations or current fluctuations that appear, and (2) Periodic active power fluctuations are given to the power generation output, and periodic voltage fluctuations or currents that appear during the transition to isolated operation Active power fluctuation method that detects fluctuations, and (3) Load that detects sudden changes such as voltage fluctuations or current fluctuations, etc. that appear at the time of independent operation by inserting parallel impedance instantaneously and periodically into the power generation equipment Fluctuation method and (4) Q which detects the frequency change rate (df / dt) of the system, changes the output voltage of the power generation facility according to the sign of the change rate and the magnitude, and detects the frequency change at the time of single operation Mode frequency shift method, and (5) A property that shifts to a frequency determined by the frequency characteristics of the power generation equipment and the load characteristics of the single system when shifting to the single operation by giving a bias to the frequency characteristics output from the power generation equipment May be a frequency shift method that detects an isolated operation, and any one of (1) to (5) may be used in combination.

In the present invention, the representative machine selection means is
Assign sequential identification numbers to all power generation facilities in advance,
Among the identification numbers of the power generation facilities in operation, the power generation facility having an identification number of a predetermined order is selected as a representative machine.

  According to the present invention, each power generation facility is assigned an identification number ID, and each power generation facility acquires the operating status of the power generation facilities in a predetermined order, and the power generation facilities in the predetermined order are operating. If not, the machine is automatically selected so that it becomes the representative machine. In this way, when the representative machine is set artificially, there is no problem that the isolated operation cannot be detected when the power generation facility is stopped, and only one unit is selected as the representative machine at all times. Will be. The above-mentioned predetermined order may be the highest order, but may be the lowest order, or any other order.

Further, the present invention includes the above-described isolated operation detection device for power generation equipment,
Each power generation facility
A circuit breaker which is interposed between the commercial AC power system and the power generation means, and is shut off when the single operation is detected by the single operation detection means and when the single operation detection signal is received from another power generation facility;
And a means for transmitting the isolated operation detection signal detected by the isolated operation detection means to another power generation facility.

  According to the present invention, since only one of the power generation facilities that are always in operation is selected as a representative machine, there is no mutual interference of electrical phenomena that achieves the function of detecting an independent operation. Such mutual interference does not occur even if the methods for achieving the principle of detecting driving are different from each other. Moreover, the redundancy of the configuration and operation can be eliminated, and the injection of redundant fluctuation signals can be avoided, and this can be achieved especially by setting the aforementioned output coefficient A to less than 1.

  FIG. 1 is an electric circuit diagram showing the overall configuration of an embodiment of the present invention. The commercial AC power system 1 outputs a commercial AC power of a certain output power frequency, for example, 60 Hz or 50 Hz, to the distribution line 4 through the circuit breaker 3 sent from the substation, and supplies it to the consumers 5, 6 and 7 To do. In the customer 5, a plurality of N0 power generation facilities 8 are connected to a common power line 9, and one or a plurality of loads 12 are connected to the power line 9 via a circuit breaker 11. The line 9 is connected to the aforementioned distribution line 4 from the line 14 via the circuit breaker 13. Each power generation facility 8 may constitute a cogeneration system, for example. The configuration of each power generation facility 8, and hence the output capacity, may be the same or different. In this embodiment, “equal” includes “substantially equal”.

  FIG. 2 is a block diagram showing a specific configuration related to the power generation facility 8 installed in the customer 5. The prime mover 15 drives the synchronous generator 16 to rotate. The electric power from the synchronous generator 16 is converted into DC power by the converter 18 constituting the system inverter 17, and then the DC power is converted into AC power by the inverter 19, further smoothed and output to the line 21. . The line 21 is connected to the power line 9 common to the plurality of power generation facilities 8 via the circuit breaker 22 and the line 23.

  An output detector 25 is connected to the line 23. The output detector 25 detects the voltage and current of the AC power output from the power generation facility 8 via the line 23 and supplies a signal representing the detection result to the control circuit 26. The control circuit 26 is realized by a microcomputer, for example, and the control circuit 26 derives a control signal on the line 29 in response to the output of the output detector 25. This control signal is a signal for controlling the power led out to the lines 21 and 23 by the inverter 19 and controlling the power factor of the power to be 1. The control circuit 26 is provided with outputs from the input means 27 and the identification number setting circuit 28, respectively. When the operator operates the input means 27, an operation signal for operating the power generation facility 8 is generated, the operation by the power generation facility 8 is started, and the operation is ended. The identification number setting circuit 28 assigns and sets sequential identification numbers in advance corresponding to all the power generation facilities 8 of the plurality N0.

  The control circuit 26 is connected to the communication line 32 via a communication circuit 31 that performs transmission / reception operations. The communication line 32 is connected to the communication circuits 31 for all the power generation facilities 8 of the plurality N0 introduced into one customer 5, and can exchange signals.

  A processing circuit 34 realized by a microcomputer or the like is provided for detecting the isolated operation. The processing circuit 34 generates a fluctuation signal and outputs it to the line 36.

  The processing circuit 34 has a fluctuation signal derived from this processing circuit 34 on the line 36 having a predetermined frequency, for example a frequency less than the output power frequency of the inverter 19, for example 1 Hz, and its amplitude, and hence the peak to peak value. Then, it is changed and set by the amplitude setting signal given from the control circuit 26 via the line 38.

  The frequency detector 37 detects the frequency of the output power of the AC power output from the inverter 19 to the line 21 and supplies the output to the processing circuit 34. The processing circuit 34 responds to the output of the frequency detector 37 and shuts off the circuit breaker 22 when the detected frequency fluctuation range Δf is equal to or greater than a predetermined discrimination level Δf0. Instead of shutting off the circuit breaker 22 or at the same time as shutting off the circuit breaker 22, the circuit breaker 13 connected to the common power line 9 may be cut off.

  The control signal from the control circuit 26 via the line 29 and the fluctuation signal from the processing circuit 34 via the line 36 are supplied to the adding circuit 41 and added and synthesized. The composite control signal from the adder circuit 41 is supplied to the inverter 19 so that the output power of the line 21 becomes a power factor of 1 and an output fluctuation for detecting an isolated operation occurs. Is controlled. 1 is realized by the processing circuit 34, the frequency detector 37, a part of the control circuit 26, the identification number setting circuit 28, the communication circuit 31, and the like.

  FIG. 3 is a diagram for explaining the operation of the power generation facility 8 shown in FIG. FIG. 3A shows the output power derived from the inverter 19 of the interconnection inverter 17 to the line 21, and FIG. 3B shows the voltage frequency of the output power in the line 21. Before the time t1, the circuit breakers 22 and 13 are closed, and the interconnection operation is in progress. Although the reactive power of the output power of the line 21 fluctuates due to the fluctuation signal, the output voltage remains substantially constant, the frequency of the output voltage is also substantially constant, and the frequency fluctuation is a value close to zero. And is less than the above-described discrimination level Δf 0 in the processing circuit 34.

  When the circuit breaker 3 from the substation of the commercial AC power system 1 is opened at time t1, the reactive power of the line 21 hardly changes and its output voltage fluctuates. This voltage variation is a variation in power consumption of the load 11 that is supplying power from the line 21 and consequently appears as a frequency variation. When the processing circuit 34 detects that the frequency fluctuation range Δf is equal to or higher than the discrimination level Δf0 as shown in FIG. 7 described later, the circuit breaker 22 is cut off.

  FIG. 4 is a flowchart for explaining the operation of the control circuit 26 shown in FIG. When the input means 27 is operated by the operator in step b1 and the operation signal is given to the control circuit 26, in step b2, the operation signal is transmitted to another power generation facility 8 by the operation of the communication circuit 31, and The operation signal from the power generation facility 8 is received, and thus the operation status of the other power generation facilities 8 is grasped. In step b3, an ID signal representing an identification number set by the identification signal setting circuit 28 is transmitted to the operating power generation facility 8 by the communication circuit 31, and an ID signal from the operating power generation facility 8 is received. . In step b4, the number N of operating power generation facilities 8 among the plurality N0 is counted. In step b5, a representative machine is selected from the plurality of N operating power generation facilities 8. The operation of step b5 is shown in FIG.

  In step b6, it is determined whether or not the selected representative machine is its own power generation facility 8. When it is determined that the power generation facility 8 is the representative machine, the process proceeds to step b7, and the amplitude setting signal for setting the amplitude, which is the value of the fluctuation signal derived from the processing circuit 34 to the line 36, is displayed on the line 38. To the processing circuit 34.

When the configurations of the plurality of N power generation facilities 8 that are operating are the same or the output capacities are equal, the amplitude that is the value of the fluctuation signal that is used when only the single power generation facility 8 is operating is B1. The number of operating power generation facilities counted in the above-described step b4 is N, and an output coefficient A that is a predetermined value is predetermined within a range of 0 <A ≦ 1 as shown in FIG. The fluctuation signal B is
B = B1, N, A (1)
Set to

  In step b8, the processing circuit 34 outputs a signal instructing the processing circuit 34 to achieve the isolated operation detection operation so that the processing circuit 34 operates at the set amplitude B of the fluctuation signal. In step b9, the self is the representative machine of the power generation facility 8, and performs an operation for detection of the isolated operation. When the isolated operation is detected, the process proceeds to step b13 and the circuit breaker generated by the processing circuit 34 A signal for blocking 22 is received and transmitted from the line 32 to another power generation facility 8 in operation by the communication circuit 31. When the other power generation equipment 8 in operation receives this signal, it breaks the circuit breaker 22.

  When it is determined in step b6 that the power generation facility 8 is not a representative machine, in step b10, the operation for detecting the independent operation by the processing circuit 34 is instructed to be disabled. As a result, the processing circuit 34 does not generate a fluctuation signal to the line 36.

  In step b11, in the operating power generation equipment 8 that is not the representative machine, it is determined whether a cutoff signal is received from the representative machine via the line 32 and the communication circuit 31, and this cutoff signal is received from the power generation equipment 8 of the representative machine. When it is determined that the circuit breaker 22 has been operated, the circuit breaker 22 is disconnected in step b12.

  The process proceeds to step b14 where it is determined that the isolated operation of the representative machine is not detected in step b9. In step b14, it is determined whether the power generation facility 8 is stopped. When it is determined that the power generation facility 8 is stopped, the process proceeds to step b15. If it is determined in step b14 that the power generation facility 8 has not stopped, the process proceeds to step b2, and the operating status of the other power generation facilities 8 is grasped again.

  FIG. 5 is a flowchart specifically showing an operation for the control circuit 26 shown in FIG. 2 to select a representative machine in step b5 of FIG. Moving from step c1 to step c2, the result of transmitting / receiving the operation signal of the power generation facility 8 in step b2 of FIG. 4 through the communication circuit 31 and the self and other operating power generation facilities transmitted / received in step b3 of FIG. Based on the exchange result of the ID signal representing the identification number, in step c3, it is determined whether or not a power generation facility having an identification number higher than the identification number of its own power generation facility is operating. If there is no operating power generation facility 8 having an identification number higher than that of the own power generation facility 8, in the next step c4, the own power generation facility 8 is selected and set as a representative machine.

  In step c5, it is determined whether or not the power generation facility 8 selected as the representative machine has been stopped by operating the input means 27. If it is determined that the power generation facility 8 has been stopped, a new representative machine is selected in step c6. Perform the operation again. In another embodiment of the present invention, the power generation facility 8 having the lowest identification number among the identification numbers of the power generation facility in operation may be selected as a representative machine, or other predetermined order identification The power generation facility 8 having the number may be selected as a representative machine.

  FIG. 6 is a diagram for explaining the output coefficient A used by the control circuit 26 shown in FIG. 2 to set the amplitude B, which is the value of the fluctuation signal, in step b7 of FIG. The output coefficient A is determined so as to decrease as the number of operating power generation facilities 8 increases. The function of the output coefficient A is, for example, a linear line. As a result, when the number of power generation facilities 8 in operation increases, the amplitude of the fluctuation signal derived from the processing circuit 34 in the representative machine to the line 36 is controlled as necessary, and the detection of the isolated operation can be reliably achieved. It becomes like this.

  FIG. 7 is a flowchart for explaining the operation for detecting the isolated operation of the processing circuit 34 shown in FIG. From step d1 to step d2, the frequency detector 37 detects the frequency of the output power of the line 21. In step d3, it is determined whether or not the fluctuation range Δf of the frequency f detected by the frequency detector 37 is equal to or greater than a predetermined discrimination level Δf0. If the detected frequency fluctuation range Δf is less than the discrimination level Δf0, it is determined in step d4 that the power generation facility 8 is connected to the commercial AC power system 1. If the detected frequency fluctuation range Δf is equal to or greater than the discrimination level Δf0, it is determined in step d5 that the circuit breaker 3 of the commercial AC power system 1 is shut off, and the isolated operation has occurred. Is supplied to the circuit breaker 22 to shut off the circuit breaker 22. Further, the cutoff signal is given to the control circuit 26 in this step d5, and the cutoff signal is given from the communication circuit 31 to the other power generation equipment 8 through the line 32 as described above. The circuit breaker 22 is interrupted by the execution of steps b11 and b12 in FIG.

  FIG. 8 is a block diagram showing a specific configuration related to the power generation facility 8a introduced into the consumer 5 according to another embodiment of the present invention. The embodiment shown in FIG. 8 is similar to the embodiment shown in FIGS. 1 to 7 described above, and corresponding parts are denoted by the same reference numerals and suffix a. It should be noted that a field current is supplied from an automatic voltage regulator 44 to the field coil 43 provided at a fixed position provided in the synchronous generator 16 driven by the prime mover 15 and excited. The line 21 to which the electric power from the synchronous generator 16 is supplied is provided with a voltage detector 25a that detects the voltage of the output electric power. The automatic voltage regulator 44 gives the excitation power to the field coil 43 so that the output voltage of the line 21 detected by the voltage detector 25a becomes a predetermined value, and thus the field current of the field coil is adjusted. Is done.

  The processing circuit 34 a realized by a microcomputer or the like has the same configuration as the processing circuit 34 in the above-described embodiment, generates a fluctuation signal, derives it on the line 46, and gives it to the adding circuit 45. The adder circuit 45 adds the output of the voltage detector 25 a and the fluctuation signal via the line 46, and gives it to the automatic voltage regulator 44. When the power generation facility 8a is connected to the commercial AC power system 1, the reactive power fluctuates among the output power of the synchronous generator 16 due to the fluctuation signal, but the output voltage in the line 21 is kept almost constant. The frequency of the output voltage is substantially constant, and the frequency fluctuation range is a value close to zero, which is less than the discrimination level as in the above-described embodiment. When the circuit breaker 3 is opened, the reactive power of the synchronous generator 16 hardly changes, its output voltage fluctuates, and fluctuations in the output voltage on the line 21 affect frequency fluctuations. In this way, the frequency fluctuation range Δf of the output voltage changes greatly during the single operation.

  FIG. 9 is a diagram for explaining the operation of the power generation facility 8a shown in FIG. As shown in FIG. 9 (1), the reactive power derived by the synchronous generator 16 to the line 21 is relatively large in the interconnection state before the time t1, and at this time, shown in FIG. 9 (2). Thus, the frequency f detected by the frequency detector 37 of the output voltage of the line 21 is constant as the frequency of the commercial AC power system 1, and the fluctuation range Δf of the frequency f is substantially zero. FIG. 9 (3) shows the waveform of the fluctuation signal derived from the processing circuit 34a via the line 46. For example, the frequency is 1 Hz, and the peak to peak value is a predetermined constant value.

  When the circuit breaker 3 is cut off at time t1 and the consumer 5 is disconnected, the reactive power of the line 21 is small after time t1, and the fluctuation width Δf of the frequency f of the output voltage becomes large. When the detected fluctuation range Δf of the frequency f is equal to or higher than the discrimination level Δf0 in the processing circuit 34a as described above with reference to FIG. 7, it is detected that an isolated operation has occurred. Other configurations and operations are the same as those of the embodiment shown in FIGS.

  The prime mover 15 may be, for example, an internal combustion engine, and its fuel supply flow rate such as gas fuel is kept constant. In addition to the internal combustion engine, the synchronous generator 16 may have, for example, a steam turbine and other configurations. Instead of the combination of the prime mover 15, the synchronous generator 16, and the converter 18, a DC power source such as a solar cell or a fuel cell may be used.

  The configuration for detecting an isolated operation provided in each power generation facility 8 is not limited to the above-described configuration, and may be realized by other configurations.

In the present embodiment, the amplitude B of the fluctuation signal is determined in step b7 based on the number N of operating power generation facilities 8, the amplitude Bi, and the output coefficient A, but the present invention is not limited to this. For example, in step b4, the control circuit 26 acquires the output capacity of the power generation facility 8 as the representative machine. Further, the control circuit 26 acquires the output capacity of the other power generation facilities 8 excluding the representative machine that is operating via the communication circuit 31. When the output capacity of the power generation facility 8 of the representative machine is Pi, the amplitude Bi is the value of the fluctuation signal used when only the representative machine is in operation, and the total output capacity of the power generation equipment in operation is ΣP The amplitude B of the fluctuation signal is
B = Bi · (ΣP / Pi) · A (2)
Set to Thereby, even if it is a case where it has a power generation installation from which output capacity differs, an independent operation detection operation can be performed. At this time, the output coefficient A is determined so as to decrease as the total output capacity of the operating power generation equipment 8 increases. The function of the output coefficient A is, for example, a linear line. As a result, when the total output capacity of the power generation equipment 8 in operation increases, the amplitude of the fluctuation signal derived from the processing circuit 34 to the line 36 in the representative machine is controlled as necessary to ensure the detection of the isolated operation Will be able to achieve.

  In the present embodiment, all the power generation facilities 8 of the plurality of units N0 connected to the power line 9 at the customer 5 are provided with the single operation detection device 40. However, the present invention is not necessarily limited to such a configuration. The isolated operation detection device 40 may be connected to only a few power generation equipments 8 of N0. For example, the single operation detection device 40 may be connected to only one power generation facility 8. In this case, by always operating the power generation equipment 8 to which the isolated operation detection device 40 is connected, the function of detecting the isolated operation is always effective. Accordingly, it is not necessary to select a representative machine, and steps b5, b6, b10, b11, b12 can be omitted in the flowchart shown in FIG. Therefore, by connecting the single operation detection device 40 to at least one power generation facility 8, the single operation can be detected and the single operation can be detected quickly. Further, since the single operation detection device 40 is connected to only one power generation facility, the configuration of the other power generation facilities is simple. Therefore, the manufacturing cost of other power generation facilities can be reduced. In the present embodiment, the power generation facility 8 serving as a representative machine when determining the fluctuation signal is the power generation facility 8 including the isolated operation detection device 40.

1 is an electric circuit diagram showing the overall configuration of an embodiment of the present invention. It is a block diagram which shows the specific structure relevant to the power generation equipment 8 introduced into the consumer 5. It is a figure for demonstrating operation | movement of the power generation equipment 8 shown by FIG. 3 is a flowchart for explaining the operation of a control circuit 26 shown in FIG. 5 is a flowchart specifically showing an operation for the control circuit 26 shown in FIG. 2 to select a representative machine in step b5 in FIG. FIG. 5 is a diagram for explaining an output count A used by the control circuit 26 shown in FIG. 2 for setting an amplitude B that is a value of a fluctuation signal in step b7 of FIG. 3 is a flowchart for explaining an operation for detecting an isolated operation of the processing circuit 34 shown in FIG. 2. It is a block diagram which shows the specific structure relevant to the power generation equipment 8a introduced into the consumer 5 in the other form of implementation of this invention. It is a figure for demonstrating operation | movement of the power generation equipment 8a shown by FIG. It is a figure which simplifies and shows a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Commercial AC power system 3 Sending circuit breaker 4 Distribution line 5, 6, 7 Customer 8, 8a Power generation equipment 11, 13, 22 Circuit breaker 12 Load 15 Motor 16 Synchronous generator 17 System interconnection inverter 18 Converter 19 Inverter 25 Output detector 26 Control circuit 27 Input means 28 Identification signal setting circuit 31 Communication circuit 32 Communication line 34, 34a Processing circuit 37 Frequency detector 40 Single operation detection device 44 Automatic voltage regulator

Claims (7)

Including multiple power generation facilities, each power generation facility
Power generation means for connecting the generated power to a commercial AC power system, receiving a fluctuation signal, and changing the generated power;
A single operation detection means for generating a fluctuation signal and supplying it to the power generation means, and detecting a single operation according to the state of fluctuation of the generated power;
Representative machine selection means for selecting one of the operating power generation facilities as the representative machine,
An operation instruction means for operating the isolated operation detecting means when selected as the representative machine by the representative machine selecting means, and stopping the isolated operation detecting means when not selected as the representative machine ;
Counting means for counting at least one of the number of units in operation and the output capacity,
The isolated operation detection means is generated by determining the value of the fluctuation signal based on the number of operating units and the output capacity counted by the counting means when selected as the representative machine by the representative machine selection means. Equipment single operation detection device. The output capacity of each power generation equipment is equal,
When counting the number of power generation facilities in operation by the counting means,
The fluctuation signal value B generated by the isolated operation detecting means is B1, the fluctuation signal value of the single power generation facility is B1, the counted number of operating power generation facilities is N, and A is a predetermined value. When 0 <A ≦ 1,
B = B1, N, A
The isolated operation detection device for a power generation facility according to claim 1, wherein When counting the total output capacity of the power generation equipment in operation and the output capacity of the representative machine,
The value B of the fluctuation signal generated by the isolated operation detecting means is set to Bi as the value of the fluctuation signal of the representative machine, and the total output capacity of the counted power generation facilities in operation is set to ΣP, the output capacity Pi of the representative machine, When A is a predetermined value and 0 <A ≦ 1,
B = Bi · (ΣP / Pi) · A
The isolated operation detection device for a power generation facility according to claim 1, wherein The islanding detection means
Including an inverter that converts DC power into AC power and flows back into the commercial AC power system,
The isolated operation detection device for a power generation facility according to any one of claims 1 to 3 , wherein the inverter varies and outputs the generated power according to a variation signal. Power generation means
A synchronous generator,
Including an automatic voltage regulator for adjusting the field current of the synchronous generator,
The isolated operation detection device for a power generation facility according to any one of claims 1 to 4 , wherein the isolated operation detection means changes the reactive power by supplying a fluctuation signal to the automatic voltage regulator. Representative machine selection means is
Assign sequential identification numbers to all power generation facilities in advance,
Of the identification number included in the power generation equipment in operation, the power generating plant according to one of claims 1 to 5, characterized in that selecting a power generation facility with the identification number of the order specified in advance as a representative machine Single operation detection device. A single operation detection device for a power generation facility according to one of claims 1 to 6 ,
Each power generation facility
A circuit breaker that is interposed between the commercial AC power system and the power generation means, and is shut off when the single operation is detected by the single operation detection means and when the single operation detection signal is received from another power generation facility;
And a means for transmitting the isolated operation detection signal detected by the isolated operation detection means to another power generation facility.

Images