JP4636404B2 - Control equipment for private power generation facilities - Google Patents

Description

  The present invention relates to a control device that performs start-stop of a private power generation facility and control of generated power.

  As shown in FIG. 5, the basic configuration of the grid-connected private power generation facility includes a generator 1, a prime mover 2, a speed governor 3, a power generation controller 4, an automatic voltage regulator (AVR) 5, and a circuit breaker 6 Connected to the premises system via the power supply to supply power to the customer power load 8 (shown collectively as one load, but actually consists of a plurality of loads), and further connected to the power system via the circuit breaker 9 Has been. In addition, a generator protection device 10 for protecting a generator abnormality as a protection device and a grid connection protection device 11 for connection protection with the power system are installed. In such a private power generation facility connected to the grid, the generator output is controlled by the power generation controller 4. In the generated power control, the power generation controller 4 uses the feedback signal of the power measurement value from the private power generation facility power meter 12 and the received power meter 13 and the received power setting value set by the received power setting device 30 to generate a power generation command. The value is determined, the governor 3 is operated, and the generator output is controlled. Here, the received power set value means the power received from the power company and supplied to the power required by the consumer power load 8. The generator output is controlled to output power obtained by subtracting the received power set value from the power of the consumer power load 8.

  At this time, when power is supplied to the consumer power load 8, both the power received from the power company and the power using the private power generation facility are used. An important consideration. At the time of daytime power peak (generally, the peak of power load is in the daytime), since the price of power purchased from the power company is high, control is performed so that the private power generation facility is operated as much as possible. On the other hand, the purchased power price at night is set to a price that is cheaper than that of the daytime, which is cheaper than the power price of the private power generation facility, so that the power received from the power company is controlled as much as possible. Against this background, in the past, private power generation facilities have basically been stopped at night, and when the power of the customer power load 8 is likely to exceed the contract power with the power company, the private power generation facilities are operated. Yes.

  The generator start setting value from the generator start setting device 31 and the generator stop setting value from the generator stop setting device 32 in FIG. As shown in the flowchart of FIG. 6, the received power with respect to the total value of the received power setting value and the generator start setting value of determination 1 (the private power generation facility is stopped, so the received power in this case is the consumer power load) The power generation equipment for private use is started when the load power is equal to 8). For example, if the lower limit operation output is 30% of the generator rated output, the generator start setting value is 10% in consideration of the lower limit operation output determined in consideration of the life of the engine when the generator is operated. % Plus 40% is the generator start setting value. After starting the private power generation facility, the system is operated with constant received power control that changes the output on the private power generation facility side so that the received power is equal to the received power set value. Furthermore, when the load power of determination 2 (= received power + generated power) falls below the sum of the received power set value and the generator stop set value, the private power generation facility is stopped. The generator stop set value is the lower limit operation output value of the generator described above.

As related prior art documents, Patent Document 1 and Patent Document 2 disclose a control method of received power from a commercial power system in a system including a private power generation facility that is connected to a commercial power system and supplies power to a consumer power load. Has been.
JP-A-11-69634 JP 2001-95157 A

  As described above, in the conventional start / stop of the private power generation facility and the generated power control according to the flow of FIG. 6, when the private power generation facility has to be started at night when it is desired to use cheap power of the power company as much as possible. As in the daytime, when the load increases, the operation of the private power generation facility side, which increases the output of the private power generation facility side with constant control of the received power, was performed, so the power from cheap power companies could be fully utilized. There is no problem. In addition, since the private power generation facility is operated at a low load factor, there is a problem that the private power generation facility operates in a high-cost area with low fuel efficiency.

  Furthermore, since the maintenance cost of the private power generation facility is associated with the operation time, it is problematic from the viewpoint of maintenance cost to operate at night when you do not want to operate as much as possible.

  The present invention has been made in view of the circumstances as described above, and the problem is that the power company's power is related to the start / stop of the private power generation facility and the generated power control in the time zone mainly for power purchase from the power company. The purpose is to provide a control device for a private power generation facility that is used more frequently and takes into account the fuel cost and maintenance cost of the private power generation facility.

In order to solve the above-mentioned problem, the invention according to claim 1 is provided with a private power generation facility that is connected to a commercial power grid of a power company and supplies power to a consumer power load, and the price of purchased power from the power company is private. Received power that detects the received power received by the customer from the power company in the control device of the private power generation facility that controls to use the power on the commercial power system with priority when it is cheaper than the power price of the power generation facility A power meter for detecting the amount of power received by the consumer from the power company in the specified 30 minutes, a power generation facility power meter for detecting the output power from the private power generation facility, and the specified 30 The power generation equipment watt-hour meter for detecting the amount of output power from the private power generation equipment for a minute and the received power watt-hour meter for about 10 minutes from the first 5 minutes of the specified 30 minutes Calculated by doubling the predicted received power amount for 30 minutes by the received power amount prediction means for predicting the received power amount for 30 minutes specified from the amount of electric power, and the received power amount prediction means. Comparing the average received power predicted value for 30 minutes with the level determination value by the level determination setter, and when the received power predicted value is larger, a comparator that outputs a start command to the private power generation facility, and the private power generation facility A power generation output setter for setting a power generation output value; and a subtracting unit for subtracting a value obtained by dividing the level determination value by the level determination value setter by 2 from the received power amount for 30 minutes predicted by the received power amount prediction unit; A switch for outputting a result of subtraction by the subtracting means to a subsequent means when a start command is output from the comparator; and the subtracting means obtained via the switch The power supply time setting means for deriving a time interval for supplying power to the consumer load by the private power generation facility by dividing the subtraction result by the power generation output value by the power generation output setting device, and the load power supply time setting means A timer that outputs a stop command to the private power generation facility when the private power generation facility supplies power to the consumer power load at a predetermined time interval, and starts the private power generation facility by the output from the comparator, and the power generation output The power generation output value set by the setting device is operated as the generated power target value, and the private power generation facility is stopped by the output from the timer.

  According to the present invention, in a private power generation facility that supplies power to a consumer power load in conjunction with a commercial power system of an electric power company, the electric power of the electric power company is used as much as possible during times when the purchased electric power from the electric power company is inexpensive. On the other hand, it is possible to provide a control device for starting and stopping the private power generation facility and controlling the generated power, which enables reduction in fuel cost and maintenance cost even in the private power generation facility.

The best mode for carrying out the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a configuration diagram of the first embodiment of the present invention. A configuration different from FIG. 5 showing a conventional private power generation facility is a received power set value from a received power setting device 30 as an input to the power generation controller 4. The generator start setting value from the generator start setting device 31 and the generator stop setting device 32 are not used, but the level determination value from the level determination value setting device 36 and the hysteresis setting value from the hysteresis setting device 33 are used. And the point where the minimum power generation output set value by the minimum power generation output setting unit 34 is used after the private power generation facility is started.

FIG. 2 is a flowchart showing start and stop of the private power generation facility in the first embodiment.
Unlike the conventional flow chart for starting and stopping the private power generation facility shown in FIG. 6, the determination of the start of the private power generation facility is performed by the following equation (1), and the determination of the stop of the private power generation facility is performed by the following equation (2). Is going. The expression (1) has the function of the comparator 1, and the expression (2) has the function of the comparator 2.
Received power> level judgment value (1)
(Level judgment value-Hysteresis set value)> Load power (2)

  In the present embodiment, the private power generation facility is started when the received power exceeds the level determination value as expressed by equation (1). After start-up, operation is performed with constant generated power control using the minimum generated output set value by the minimum generated output setter 34, and the load power is lower than the value determined by the hysteresis set value from the level judgment value as shown in equation (2). The private power generation equipment will be stopped when Below this, the minimum power generation output set value indicates the limit at which the generator is not operated from the viewpoint of the life of the engine, and is the same value as the generator stop set value by the generator stop setter 32 in FIG. The meaning of the hysteresis set value is to prevent starting immediately after the stop by stopping the private power generation facility when the load power is sufficiently reduced.

  According to this embodiment, since the generator is operating at a constant minimum power output, the fluctuation of the load power will be covered by the power company's power, the power company's power usage will increase, and the conventional method More effective (economic) than

(Second Embodiment)
FIG. 3 is a block diagram of the second embodiment of the present invention.
As shown in FIG. 3, this embodiment is different from the first embodiment of FIG. 1 in that the level judgment value from the level judgment value setting unit 36 and the power generation output from the power generation output setting unit 35 are compared with the power generation controller 4. A set value is input, and a processing block shown in FIG. In addition, a private power generation equipment watt-hour meter 14 that detects the amount of output power from the private power generation equipment and a received power watt-hour meter 15 that detects the amount of power received from the power company are provided. There is no minimum power output setting device.

FIG. 4 is a configuration diagram showing a start / stop process of the private power generation facility according to the present invention.
As shown in the figure, a signal of the received power amount from the received power meter 15 (the private power generation facility is not in operation, so the received power amount is equal to the load power amount at this time) is received, and the received power amount prediction means 21 To predict the amount of received power in the 30-minute section. For example, the prediction is made by predicting the received power amount for the entire 30 minutes from the received power amount for the first 10 minutes of the 30-minute section. In this case, the received power amount prediction value may be multiplied by three. Further, this assumes that the power receiving electric Chikara予 Hakachi of 30 minutes interval average doubling, compared with level determination value comparator 22, a start command when the larger receiving electric Chikara予 Hakachi Output. In addition, the value obtained by dividing the level judgment value by 2 from the predicted value of the received power amount is subtracted to obtain the power amount d provided on the private power generation facility side, and the power amount d is divided by the power generation output set value e to generate private power generation. Load power supply time setting means d / e for setting the time for supplying power from the facility to the consumer power load is provided. When the timer 23 passes the time for supplying power from the private power generation facility, a stop command is output. The switch 24 is provided in order to set the timer 23 with a time for supplying power to the consumer power load 8 from the private power generation facility after the start command is output. That is, the timer 23 outputs a stop command to the private power generation facility when the private power generation facility supplies power to the consumer power load at the time interval set by the load power supply time setting means d / e .

  By setting the power generation output set value to a high load factor with good fuel efficiency of the private power generation facility, the fuel efficiency of the private power generation facility is improved. In addition, since it takes only a short time to drive for 30 minutes at a low load factor with low fuel consumption, it leads to a reduction in the total operation time of the private power generation facility, and the timing of maintenance based on the total operation time can be delayed. This is effective in reducing maintenance costs.

  This embodiment pays attention to the point determined based on the average power value of the 30-minute section obtained by doubling the value of the received power amount every 30 minutes in which the contract power with the power company is defined, Since the amount of power received for 30 minutes does not exceed the amount equivalent to the amount of contracted power, it would be good to operate the private power generation facility for a short time at a high load factor with good fuel efficiency while responding to the increase in load power. The power generation cost of private power generation facilities is suppressed.

The block diagram of the private power generation equipment connected with the electric power company commercial system in 1st Embodiment of this invention. The flowchart which shows the start stop of the private power generation equipment in FIG. The block diagram of the private power generation equipment linked with the electric power company commercial system in 2nd Embodiment of this invention. The block diagram which shows the start stop of the private power generation equipment in FIG. The block diagram of the private power generation equipment connected with the conventional electric power company commercial system. The flowchart which shows the start-stop of the conventional private power generation equipment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Generator, 2 ... Prime mover, 3 ... Speed governor, 4 ... Power generation controller, 5 ... AVR, 6, 7, 9 ... Circuit breaker, 8 ... Consumer power load, 10 ... Generator protection device, 11 ... System Interconnection protection device, 12 ... private power generation equipment watt meter, 13 ... received power meter, 14 ... private power generation equipment watt meter, 15 ... received power meter, 21 ... received power amount prediction means, 22 ... comparator, 23 ... Timer ... 24 ... Switch, 30 ... Received power setting device, 31 ... Generator start setting device, 32 ... Generator stop setting device, 33 ... Hysteresis setting device, 34 ... Minimum power generation output setting device, 35 ... Power generation output setting device, 36: Level judgment value setting device.

Claims (1)

A private power generation facility that supplies power to the consumer power load in conjunction with the commercial power grid of the power company is provided, and when the price of purchased power from the power company is lower than the power price of the private power generation facility, In the control device for private power generation equipment that controls to use power preferentially,
A receiving wattmeter for detecting received power received from a power company by a consumer;
A watt-hour meter that detects the amount of power received by a consumer from a power company in a specified 30 minutes;
A power generation equipment wattmeter for detecting the output power from the private power generation equipment;
A private power generation facility watt-hour meter for detecting the amount of output power from the private power generation facility for a prescribed 30 minutes;
The received power amount predicting means for predicting the received power amount for 30 minutes specified from the received power amount detected by the received power meter in about 10 minutes from the first 5 minutes of the specified 30 minutes; The received power amount prediction means compares the predicted received power amount of 30 minutes calculated by doubling the predicted received power amount of 30 minutes with the level determination value by the level determination setter, A comparator that outputs a start command to the private power generation facility when the received power predicted value is larger;
A power generation output setting device for setting a power generation output value of a private power generation facility;
Subtracting means for subtracting a value obtained by dividing the level judgment value by the level judgment value setting unit by 2 from the received power quantity for 30 minutes predicted by the received power quantity prediction means;
When a start command is output from the comparator, a switch that outputs a subtraction result by the subtracting unit to a subsequent unit;
A load power supply time setting for deriving a time interval at which a private power generation facility supplies power to the customer load by dividing a subtraction result obtained by the subtracting means obtained through the switch by a power generation output value by the power generation output setting device Means,
A timer for outputting a stop command to the private power generation facility when the private power generation facility supplies power to the consumer power load at a time interval set by the load power supply time setting means,
Starting the private power generation facility by the output from the comparator, operating the power generation output value set by the power generation output setting device as the generated power target value, and stopping the private power generation facility by the output from the timer. A control device for private power generation facilities.

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