JPH03293930A - Purchase power quantity control device - Google Patents

Abstract

PURPOSE:To prevent a generator for home use from entering an individual operations state and enable a stable supply of power to be made to load facilities of a consumer by storing power in a fly wheel instantly when the amount of purchased power is reduced due to fluctuation of operation condition of the load facility. CONSTITUTION:When power (curve) 21 of a load facility 15 is reduced, purchased power (curve) 22 is reduced below a detection value 25 of a purchased power reduction detection device 17 from a purchased power quantity target value 24 due to it, a purchase power quantity change amount memory device 18 stores an amount of changed purchased power 26, it gives signal to a fly wheel 19, and then the purchased power 22 returns to the purchased power quality target value 24 by a storage power 27, thus enabling continuous parallel operation with a power company system by a purchased power setting which is smaller than before.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power purchase amount control device for performing parallel operation of power purchased from a power company system and a private generator.

[Conventional technology]

FIG. 5 is a circuit block diagram showing a conventional electricity purchase amount control device. In the figure, 1 is a power company system, 2 is a power receiving circuit breaker, 3 is an instrument current transformer for detecting the received power current, and 4 is a circuit block diagram showing a conventional power purchase amount control device.
is a voltage transformer for detecting the received IT pressure; 5 is a power converter that receives signals from the voltage transformer 3 and the voltage transformer 4; and 6 is a power converter that converts the received power into an appropriate signal level. A power purchase amount setter 7 sets a target value of purchased power from the company system 1, and a power purchase amount setting device 7 is used to compare the target value set by the power purchase amount setting device 6 with the actual power purchase value based on the signal from the power converter 5. A comparison amplifier that detects and amplifies the difference; 8 is the comparison amplifier 7;
An output circuit 9b receives a signal from the power converter 5 and outputs it to the outside. Power purchase amount setting device6. This is a power purchase amount control device including a comparison amplifier 7 and an output circuit 8.

Further, 10 is a steam turbine, 11 is a steam control valve that adjusts the amount of steam flowing into the steam turbine 10, 12 is a governor control device that controls the steam control valve 11, 13 is a private generator driven by the steam turbine 10, 14 is a power receiving transformer, 15 is load equipment, and 16 is a reverse power detection relay.

Next, the operation will be explained. First, when the operating status of the load equipment 15 changes, the resulting fluctuation in the load power results in a fluctuation in the purchased power from the power company system 1, and the power purchase amount control device 9b detect,
The output of the private power generator 1113 is automatically controlled so as to maintain the purchased power at a target value preset by the power purchase amount setting device 6.

That is, the purchased power signal detected by the instrument current transformer 3 and the potential transformer 4 is converted to an appropriate signal level by the power converter 5, and this signal and the target set by the power purchase amount setting device 6 are converted. The difference power signal between the values and the comparator amplifier 7
A signal corresponding to this difference power is output from the output circuit 8.

The output signal from the power purchase amount control device 9b is input to the governor control device 12, the steam control valve 11 is adjusted, the amount of steam flowing into the steam turbine IO is controlled, and the private power generator 13
By increasing or decreasing the output of the electric power company 1, the power purchased from the electric power company system 1 is automatically controlled so as to match the target value set by the power purchase amount setting device 6.

[Problem to be solved by the invention]

Since the conventional power purchase amount control device is configured as described above, when the purchased power fluctuates significantly, the power purchase amount control device 9
b. Due to the time delay of the governor control device 12 and the steam control valve 11, the actual purchased power is
It usually takes several seconds or more to return to the set target value.

Therefore, when the capacity of the load equipment 15 instantly decreases and the purchased power also decreases, if the amount of decrease in the purchased power exceeds the target value set by the power purchase amount setting device 6, For a certain period of time, power will be sent back from the private generator 13 to the power company system 1.

However, when the electric power company system 1 and the private generator 13 are operated in parallel, the electric power company informs the consumer that ``When the consumer's power receiving bank is reversed, the power receiving circuit breaker can be automatically opened.'' Because of the request for KotoJ, the customer installs a reverse power detection relay 16 at the power receiving point, and when reverse power transmission occurs, this is detected and the power receiving circuit breaker 2 is opened. .

Therefore, when reverse power transmission occurs due to a change in the operating status of the load equipment 15 as described above, the reverse power detection relay 16 operates, opens the power receiving breaker 2, and only the private generator 13 is activated. In this case, the load equipment 15 is in a standalone operation state where power is supplied to the load equipment 15, and there are problems such as fluctuation phenomena such as frequency fluctuations and voltage fluctuations occurring due to an imbalance between the output of the private generator 13 and the power required by the load equipment 150. Furthermore, in order to restore the private generator 13 by operating the normal electric power company system 1 and the private generator 13 in parallel, it is necessary to synchronously close the power receiving circuit breaker 2 which had been opened.

In order to avoid such opening of the power receiving circuit breaker 2, some consumers set the target value set by the power purchase amount setting device 6 based on the expected power fluctuation (decrease) range of the load equipment 15, that is, the decrease in the purchased power. Therefore, there were problems such as having to operate the operating output of the private generator 13 at a lower ratio than its rated value.

This invention was made to solve the above-mentioned problem, and even if the capacity of the load equipment suddenly decreases, the reverse power detection relay will not operate ← Parallel operation of the power company grid and private generator It enables the continuation of the
It is an object of the present invention to obtain a power purchase amount control device that allows a consumer whose load equipment capacity fluctuates drastically to set a lower power purchase amount than before.

As an approximation technique, published by Thermal and Nuclear Power Generation Technology Association, No. 330, 1984 (No. 3.νo 1)
, 35) Pages 287-297 r Power system operation and electrical equipment 1 ■.

There are some listed in “System operation and electrical equipment for private power generation.”

Means for Solving Problem 1] The power purchase amount control device according to the invention described in claim (1) includes a power purchase amount decrease detection device that detects that the amount of power purchased from the electric power company system has decreased below a certain value; A power purchase amount change storage device that receives a signal from the power purchase amount drop detection device and stores the amount of change in the power purchase amount for a certain period of time, and a flywheel that stores and releases power based on the signal from the power purchase amount change storage device. It is composed of the following.

In addition, the power purchase amount control device according to the invention described in claim (2) includes:
A power purchase amount drop detection device that detects when the amount of purchased power from the power company grid has fallen below a certain value, and a power purchase amount change amount that receives a signal from the power purchase amount drop detection device and stores the amount of change in the amount of purchased power for a certain period of time. A storage device and a flywheel that stores power with the stored change amount as an initial value are reduced and released at a rate lower than the output response speed of the private generator, and the stored power of the flywheel is automatically changed. It is configured with a flywheel power setting device.

[For production]

The power purchase amount control device according to the invention described in claim (1) instantly stores the power in the flywheel when the purchased power decreases due to fluctuations in the operating status of the load equipment, thereby reducing the power consumption from the operation of the reverse power detection relay. This prevents the generator from becoming isolated and enables stable power supply to the consumer's load equipment.

Furthermore, when storing power in the flywheel, the power storage value of the flywheel is automatically matched to the power purchase amount fluctuation value according to the power purchase amount fluctuation range, so that the power purchase amount is kept constant even after load fluctuations. The power purchase amount control device in the invention described in item (2) is configured to operate the flywheel in order to recover the power stored in the flywheel after absorbing the load fluctuation when the purchased power starts to decrease due to fluctuations in the operating status of the load equipment. The output of the private generator is automatically reduced by utilizing the function of the power purchase amount control device in the invention set forth in claim (1), by reducing and discharging the stored power at a rate lower than the output response speed of the private generator. By doing so, it is possible to keep the amount of electricity purchased constant even after sudden changes in load.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, parts that are the same as those in FIG. A power purchase amount change storage device 19 receives a signal from the power amount reduction detection bag W17, stores the amount of change in the power purchase amount for a certain period of time, and sets the stored power value of the flywheel 19; It is a flywheel that stores and releases electricity depending on the signal. 9a represents these power converters 5. Power purchase amount setting device6. Comparison amplifier7. Output circuit 8, power purchase amount reduction detection bag W17. Electricity purchase amount change storage device! ! This is an electricity purchase amount control device including 1B and a flywheel 19.

In general, the basic configuration of flywheel power generation equipment is (1) a generator motor (07M), (2) a flywheel (F/W) directly connected to the G/M rotating part, and (3) a flywheel installed between the 07M and the load. Power converter (P
It consists of c). In this flywheel power generation facility, 07M will be used both as a generator (when generating electricity) and an electric motor (when storing electricity). That is, at the time of power storage, 07M is operated as an electric motor, and stores energy by converting the power input from PC into rotational energy to the G/M rotating section and the F/W directly connected to the G/M rotating section. On the other hand, when generating electricity, 07M functions as a generator to convert rotational energy into electrical energy and supply electricity.

Next, the operation shown in FIG. 1 will be explained based on FIG. 2, which shows actual changes in power. First, in Fig. 2, 21 is the power of the load equipment 15 (curve), 22 is the purchased power (curve), 27
is the storage (release) power (curve) by the flywheel, 2
3 indicates the private generator output (curve) 0 For example,
As shown in the figure, when the power (curve) 21 of the load equipment 15 decreases, the purchased power (curve) 22 decreases, and the power purchase amount target value 24 falls below the detected value 25 of the power purchase amount decrease detection device 17. , stores the amount of change in the amount of purchased electricity 26 in the amount of change in amount of purchased electricity storage device 18, and gives a signal to the flywheel 19;
The purchased power 22 returns to the power purchase amount target value 24 due to the stored power 27 by the flywheel 19.

Further, FIG. 3 is a circuit configuration diagram showing another embodiment of the present invention, and 20 is a flywheel power setting device, in which the power stored in the flywheel 19 is set at a speed equal to or lower than the output response speed of the private generator 13. Decrease.

In order to release electricity, the flywheel 19 stores (discharges) the amount of change stored in the power purchase amount change amount storage device 18 as an initial value.
It changes the power automatically.

Next, the operation will be explained. If the power usage capacity of the load equipment 15 decreases and the purchased power decreases rapidly and significantly, this will be detected by the power purchase amount drop detection device 17 and a signal stored in the power purchase amount change storage device 18 will be used to detect a sudden and large decrease in the purchased power. Electric power is stored in the wheel 19. When storing power in the flywheel 19, the amount of change in the amount of purchased power is stored in the amount of change in the amount of purchased power storage device 18 so that the amount of change in the amount of purchased power is stored in the storage device 18 so that the purchased power does not fluctuate.The flywheel 19 stores power according to the range of fluctuation in the amount of purchased power. Automatically match the value to the power purchase amount fluctuation value. moreover,
After the load fluctuation is absorbed, in order to recover the power stored in the flywheel 19, the signal in the power purchase amount change storage device 18 is automatically decreased or released at a rate of change that can be followed by the output of the private generator 13. In order to recover the amount of power stored in the flywheel 19, the flywheel power setting device 20 automatically changes the power stored (released) in the flywheel 19. By automatically changing the output of the private generator 13 based on the signal from the comparison amplifier 7 to the output circuit 8, the amount of purchased electricity can be kept constant even after load fluctuations have been absorbed. and effectively utilize the electric power stored in the flywheel 19.

Next, the above operation will be explained based on FIG. 4 showing actual power changes. In FIG. 4, the same parts as in FIG.
5's power (curve) 21 decreases, thereby increasing the purchased power (
When the power purchase amount target value 24 decreases from the power purchase amount target value 24 to the detection value 25 or less of the power purchase amount decrease detection device f17, the power purchase amount change storage device 18 stores the change amount 26 in the power purchase amount, and the power purchase amount change amount 26 is stored in the flywheel 19. The purchased power 22 returns to the power purchase target value 24 by the stored power 27 by the flywheel. However, in the present invention, after a certain period of time, the flywheel power setting device 20 converts the signal from the power purchase amount change storage device 18 to the power purchase amount target value 24. By automatically changing according to a set pattern, the stored power 27 of the flywheel I9 is reduced and released at a speed lower than the response speed of the output 23 of the private generator 13, and the amount of purchased power is kept constant even after load fluctuations are absorbed. This allows the power 27 stored in the flywheel 19 to be used effectively.

〔Effect of the invention〕

As described above, according to the invention set forth in claim (1), there is provided a power purchase amount drop detection device that detects that the power purchase amount from the power company grid has decreased below a certain value, and a power purchase amount drop detection device that detects that the power purchase amount drop detection device The device consists of a power purchase amount change storage device that receives a signal and stores the amount of change in the power purchase amount for a certain period of time, and a flywheel that stores and releases power based on the signal from the power purchase amount change storage device. Customers who were operating their private generators independently due to reverse transfer due to fluctuations in the operating status of load equipment, or who had set their purchased power higher than necessary to avoid operating their private generators independently. Even at home, it is possible to continue parallel operation with the power company grid with a lower power purchase setting than before, and even after absorbing load fluctuations, parallel operation with the power company is possible without increasing the amount of power purchased more than necessary. This has the effect of

Further, according to the invention set forth in claim (2), there is provided a power purchase amount drop detection device that detects that the power purchase amount from the electric power company system has decreased below a certain value, and a power purchase amount drop detection device that receives a signal from the power purchase amount drop detection device. A power purchase amount change storage device that stores the amount of change in the amount of electricity for a certain period of time, and a flywheel that stores power with the stored change amount as an initial value, and reduces and releases the electric power at a rate lower than the output response speed of the private generator. Since the device is composed of a flywheel power setting device that automatically changes the power stored in the flywheel, the demand that conventionally required independent operation of the private generator due to reverse feeding due to fluctuations in the operating status of the load equipment can be reduced. It has the effect that stable parallel operation with the electric power company is possible even at home, and even after load fluctuations are absorbed, parallel operation with the electric power company is possible without increasing the amount of electricity purchased more than necessary.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a power purchase amount control device according to an embodiment of the present invention, FIG. 2 is a time chart showing temporal changes in power in FIG. 1, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a block diagram showing the configuration of a power purchase amount control device according to an example, FIG. 4 is a time chart showing temporal changes in power in FIG. 3, and FIG. 5 is a block diagram showing the configuration of a conventional power purchase amount control device. In the figure, 1 is the electric power company system, 6 is the power purchase amount setting device, and 9
a, 9b are power purchase amount control devices, 13 is a private generator, 17
18 is a power purchase amount change detection device; 18 is a power purchase amount change amount storage device;
19 is a flywheel, and 20 is a flywheel power setting device. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) For private use, which compares the amount of electricity purchased based on the received current and voltage from the power company system with the amount of power purchased previously set in the power purchase amount setting device, and always operates in parallel with the power company system so that the two match. A power purchase amount control device that controls a generator includes a power purchase amount decrease detection device that detects that the amount of power purchased from the electric power company system has decreased below a certain value, and a power purchase amount decrease detection device that detects when the power purchase amount decrease detection device receives a signal from the power purchase amount decrease detection device. A power purchase amount control device comprising: a power purchase amount change amount storage device that stores the amount of power change amount for a certain period of time; and a flywheel that stores and releases power based on a signal from the power purchase amount change amount storage device. (2) For private use, which compares the amount of electricity purchased based on the received current and voltage from the electric power company's system with the amount of purchased electricity set in advance on the power purchase amount setting device, and always operates in parallel with the electric power company's system so that the two match. A power purchase amount control device that controls a generator includes a power purchase amount decrease detection device that detects when the power purchase amount from the electric power company system has decreased below a certain value, and a power purchase amount decrease detection device that detects when the power purchase amount decrease detection device receives a signal from the power purchase amount decrease detection device. a power purchase amount change storage device that stores a change amount for a certain period of time; and a flywheel that stores power using the stored change amount as an initial value, and reduces the power at a rate below the output response speed of the private generator.
A power purchase amount control device comprising a flywheel power setting device that automatically changes the power stored in the flywheel.