JPH0568342A - Operation control device for non-utility generation facility - Google Patents

Abstract

PURPOSE:To operate the optimum number of generators corresponding to a load fluctuation characteristic by inferring the condition of a change in load power for each occasion from the specified inferring rule, with a gradient of a change in load power, the output of a start-up power deviation calculator, and the output of a stoppage power deviation calculator inputted. CONSTITUTION:A load power change detector 100 differentiates a signal of the load power detected by a load power calculator 14 and obtains a load change signal for a gradient of the change. When the load power exceeds the power set by a start-up power setting device 15, a start-up power deviation calculator 19A outputs a deviation signal of the two powers. When the load power becomes smaller than the power set by a stoppage power setting device 16, a stoppage power deviation calculator l9B outputs a deviation signal of the two powers. At a start-up and stoppage confirmation time interval inference device 102, the operational condition of the load or generators for each occasion is inferred from those signals based on the specified inference rule and then the start-up confirmation time interval and the stoppage confirmation time interval are determined for confirmation work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for controlling the number of operating private generators, and in particular, an operating control device for private power generation equipment capable of controlling the optimum number of operating generators according to the characteristics of load fluctuations. Regarding

[0002]

2. Description of the Related Art Normally, electric power consumers are supplied with electric power from a commercial electric power system. However, in many cases, a consumer who uses a large amount of electric power has a private power generation facility, and a private power generator takes charge of part or all of the private power. This is because the total cost of equipment, operating costs, and electricity costs can be kept low.

In addition, recently, a cogeneration system has been developed which utilizes exhaust heat from a power generation facility as heat energy. According to this system, it is possible to further reduce the total energy cost, and therefore the number of customers having private power generation facilities is increasing. As the field of application of private power generation equipment expands in this way, the variation pattern of load electric power also becomes various. In order to minimize the energy cost, it is necessary to have a plurality of private generators and operate the generators with the optimum number of operating machines according to the load power amount at each time and with the optimum generated power amount. In particular, when the load power is small, the operation of the generators is stopped, and when the load power is large, it is very important to control the number of operating generators so that a suitable number of generators are operated. However, it takes time to start and stop the private power generator, and frequent start and stop have a bad influence on the life of the equipment. Therefore, the actual control device takes these points into consideration to perform operation control.

FIG. 5 shows an example of the configuration of an operation control device in a conventional privately-used power generation facility that is generally used. In the figure, 1 is a commercial power system, 2 and 3 are private generators,
4, 5 are prime movers, 6, 7 and 8 are power detectors, 9 is a load,
10 to 13 are circuit breakers, 14 is a load power calculation device, 15,
17 is a starting power setting device, 16 and 18 are stopping power setting devices,
Reference numerals 19 and 20 are operation stop determination devices, and reference numerals 22 and 22 are confirmation time limit timers.

The operation of the conventional operation control device will be described below with reference to FIG. The load 9 is supplied with electric power from the commercial power system 1 and the private generators 2, 3 through the circuit breakers 10, 11, 12. The power supplied by the commercial power system and the private power generator is detected by power detectors 6, 7, and 8. The load power calculation device 14 adds these signals to calculate the load power. In this example, when the load power is small, the power is supplied only from the commercial power system, and when the load power is large, the private power generator 2 is operated to supply the power. When the load power further increases, the private power generator 3 is also operated to continue to supply power. On the contrary, when the load power decreases, the private generator 3 and the private generator 2 are stopped in this order. The operation stop determination device 19 starts the private power generator 2 when the load power is higher than the power set by the start power setting device 15, and the private power generation when the load power is lower than the power set by the stop power setting device 16. Machine 2
To stop.

By the way, there are some fluctuations in the load power, which increase momentarily, such as when the motor is started, but decrease immediately. In order to prevent frequent start and stop of the generator,
The stoppage judging device 19 is provided with a confirmation time limit timer 21,
After confirming that the fluctuation of the load power continues for a predetermined time or longer, start and stop the operation. Similarly, the operation stop determination device 20 uses the power set by the start power setting device 17 and the stop power setting device 18 and the confirmation time limit timer 22 to generate the private generator 3
Operation control.

[0007]

According to the conventional private power generation facility whose operation is controlled as described above, the optimum number of generators is operated according to the load power at each time, so that the operation with less loss can be achieved. it can. However, as the field of application of private power generation equipment has expanded, more sophisticated control has come to be required. For example, in the case of a mechanical device that requires an operator as a main load, there are almost fixed patterns of load fluctuations every day during attendance time, break time, leaving time, etc., for example, as shown in FIG. The daily load fluctuation pattern is known. This FIG. 6 shows changes in the average load, and does not include short-term changes. In reality, there is such a base load, and in addition, a short-time load such as an elevator, a crane, a crusher, and an arc furnace is often generated irregularly. The load fluctuation for a short time is several% to several tens% of the average load.

When the conventional control device is applied to such a fluctuating load, it is very difficult to adjust the control device so that the optimum number of operating generators can be obtained. When there are many load fluctuations, it is necessary to frequently start and stop the generators in order to maintain the optimal number of operating machines. Warm up operation when starting and stopping,
After-cooling operation is required, resulting in fuel loss. Frequent start and stop also gives thermal and mechanical stress to the prime mover and shortens the service life. In order to prevent this, conventionally, the start / stop confirmation time period is set to be long. By increasing the start / stop confirmation time limit, the generator is not started / stopped even if the load fluctuates for a short time. However, if the start / stop confirmation time limit is increased,
Since the generators are unnecessarily operated during the confirmation, there is a problem that the number of operating generators does not reach the optimum value at that time.

The conventional control device lacks the ability to control according to such a state. Therefore, conventionally, in a plant that needs to operate with an optimal operation pattern,
In addition to automatically operating the control device, an operator who monitors the situation was placed, and the operation pattern was corrected by manually starting and stopping the power generator according to the situation. However, it is not desirable to have an operator because it significantly increases the running cost of the private power generation equipment, and it has been desired to develop a more sophisticated operation control device.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an operation control device for a private power generation facility capable of operating an optimal number of operating generators according to the characteristics of load fluctuations. Especially.

[0011]

In order to achieve the above object, the present invention provides an operation control device for a private power generation facility in which power is supplied to a load in parallel by an electric power system and a private power generator or a plurality of private power generators. The load power calculation device that detects the power of the load power, the load power change detector that detects the slope of the change in the load power, the start power setting device that sets the load power that starts the specified private power generator, and the private power generator. A stop power setting device that sets the load power to be stopped, a start power deviation calculator that takes the deviation between the setting power of the starting power setting device and the load power, and a deviation between the setting power of the stopping power setting device and the load power The stop power deviation calculator, the time detector that detects the current time, and the state where the load power exceeds the set value set by the starting power setter, or the load power is set by the stop power setter Equipped with a start / stop confirmation time limit reasoner that calculates the start confirmation time limit and the stop confirmation time limit that confirm that the state below the set value is continuous, and an operation stop controller that controls the operation stop of the private generator In the start / stop confirmation time limit reasoner, the current time, the slope of the change in load power, the output of the start power deviation calculator and the output of the stop power deviation calculator are input, and the predetermined reasoning rules specific to the private power generation facility are input. Inferring the state of load power change from time to time,
It is characterized in that the start confirmation time period and the stop confirmation time period are calculated, and the operation stop of the private generator is controlled by the start confirmation time period and the stop confirmation time period.

[0012]

According to the operation control device for private power generation equipment of the present invention, the state of load change at each time is grasped and the start / stop confirmation time limit is changed to an optimum value, so that the generator is uselessly operated or stopped for confirmation. Since it is possible to always operate the private generator with the optimum number of operating units only by the automatic operation by the operation control device, it is possible to improve energy efficiency. Further, in a situation where it is determined that the confirmation time period is necessary, the confirmation time period is lengthened, so that unnecessary start and stop can be prevented, and the life of the device is not adversely affected.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, the same reference numerals as those in FIG. In FIG. 1, 19A, 19B, and 19C are decompositions of the function of the operation stop determination unit 19 in the conventional control device. 19A is a start power deviation calculator, 19B is a stop power deviation calculator, and
9C is a shutdown controller. Also, 20A, 20B,
Similarly, 20C is a decomposition of the function of the operation stop determination device 20 in the conventional control device. 20A is a start power deviation calculator, 20B is a stop power deviation calculator, and 20C is an operation stop controller. Reference numeral 100 is a load power change detector, 101 is a time detector, 102 is a start / stop confirmation time limit reasoner for the private generator (G1) 2, and 103 is a start / stop confirmation time limit reasoner for the private generator (G2) 3.

The load power change detector 100 differentiates the load power signal detected by the load power calculation device 14 to obtain a load change signal having a slope of the change. The starting power deviation calculator 19A outputs a deviation signal of both powers when the load power exceeds the power set by the starting power setting unit 15. Also,
The stop power deviation calculator 19B outputs a deviation signal of both powers when the load power becomes smaller than the power set by the stop power setting unit 16. The time detector 101 has a 24-hour clock function and generates a signal of a level proportional to the time at that time. The start / stop confirmation time limit reasoner 102 infers the load and the operating state of the generator from these four signals, determines the start confirmation time period and the stop confirmation time period, and performs the confirmation operation. In the operation stop controller 19C, the signals from the starting power deviation calculator 19A and the stopping power deviation calculator 19B,
From the start confirmation time limit and stop confirmation time limit signals to the private generator 2
Control the start and stop of the. Further, the operation stop controller 20C is also similar to the operation stop controller 19C and the starting power deviation calculator 2
The start / stop of the private generator 3 is controlled based on the signal from 0A, the stop power deviation calculator 20B, the start confirmation time limit, and the stop confirmation time limit signal.

By the way, according to the present invention, the high-level judgment conventionally made by the operator is confirmed by the start / stop confirmation time limit reasoner 102,
At 103. 2 from 4 input signals as described above
Although two outputs are obtained, the relationship between input and output signals is not linear.
In order to obtain operating characteristics equivalent to those of a skilled operator, it is necessary to program the situation determination processing in which each input signal is related in a complicated manner. In order to perform such human-like processing, an inference method based on a mathematical formula has a very complicated structure, and conventionally a control device could not be realized.

In the present invention, a fuzzy inference method is applied as described below to simplify the inference method. FIG. 2 is a detailed internal configuration diagram of the start-stop confirmation time limit reasoner 102. A microcomputer is used to perform such processing in the control device, but the processing in the microcomputer is performed by software in a time-division manner. Here, for simplification of description, each function is shown as a block along the data flow. In FIG. 2, 102a
Is an input signal membership function storage unit, 102b is an output signal membership function storage unit, 102c is a start confirmation timed inference rule base, 102d is a stop confirmation timed inference rule base, 102e is a start confirmation timed inference unit, and 102f is a stop confirmation timed period. It is an inference section.

Input signal membership function storage unit 102a
Defines a human sense of quantitative evaluation for each input signal with a membership function. For example, in the gradient of the load power change, three labels (positive large, negative large,
The data is expressed by (small), and is defined and stored in the form as shown in FIG. In FIG. 3, the horizontal axis represents input data, and the vertical axis represents the degree of conformity to each expression and is a number from 0 to 1. The other three data are similarly defined and stored. The output data is also defined in the output signal membership function storage unit 102b with the same expression. The start confirmation time limit inference rule base 102c is a rule base for storing start confirmation time limit inference rules. The configuration of the start / stop confirmation time limit reasoner 103 can also be realized by the same configuration as the start / stop confirmation time limit reasoner 102 described above.

In fuzzy inference, however, the label defined by the membership function is used to describe the rule in the same format as human language. For example, the following is stored as a part of the start rule. (1) If the deviation is large in the morning and the slope of the load change is positive and large, shorten the confirmation time period. (2) If the deviation is large in the evening and the slope of the load change is small, set the confirmation time to the middle level.

The rules and membership functions are not unconditionally determined, but the start confirmation timed inference rule base 102c.
Has a large number of unique rules according to the load characteristics of each private power generation system. In fuzzy inference, the degree of conformity of the condition part of each rule is calculated and reflected in the conclusion part. One method is shown in FIG.

Among the plural conditions of one rule, the membership function of the conclusion part is truncated with the value of the lowest fitness. The final part output is determined by synthesizing the conclusion part membership functions obtained by multiple rules and taking the center of gravity.

With this configuration, the automatic operation by the control device enables the same operation as an operator who cannot be performed by the conventional control device. Further, by using the fuzzy inference for the inference, the configuration of the control device is simplified, and the same function as that performed by the operator can be realized with the configuration substantially similar to that of the conventional control device.

In the above embodiment, it has been described that only the start / stop confirmation time limit reasoner is constructed by using the microcomputer. However, the present invention is not limited to this, and the load power calculator, the start power setter, the stop power setter, the start power deviation calculator, the stop power deviation calculator, the operation stop controller,
The load power change detector, time detector, etc. can also be realized by the function of one microcomputer. In that case, the hardware configuration of the control device can be further reduced.

[0023]

As described above, according to the present invention, the state of load change at each moment is grasped and the start / stop confirmation time limit is changed to the optimum value. Energy efficiency can be improved because the number of operating machines can be operated and the generators are not started or stopped for confirmation, and automatic operation control is possible. In particular, since it is not necessary to have an operator, it is extremely effective in saving energy and labor.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an operation control device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a start / stop confirmation time limit reasoner according to the present invention.

FIG. 3 is a diagram for explaining a membership function for fuzzy inference used in the present invention.

FIG. 4 is a diagram showing a conclusion calculation method in fuzzy inference.

FIG. 5 is a configuration diagram of a conventional operation control device.

FIG. 6 is a diagram showing an example of a load change pattern in a private power generation facility.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Commercial power system, 2, 3 ... Private generator, 4,5 ... Prime mover, 6, 7, 8 ... Electric power detector, 9 ... Load, 10-13
... Circuit breaker, 14 ... Load power calculation device, 15, 17 ... Start power setting device, 16, 18 ... Stop power setting device, 19A, 2
0A ... Starting power deviation calculator, 19B, 20B ... Stopping power deviation calculator, 19C, 20C ... Operation stop controller, 100
... load power change detector 101, time detector 102,
103 ... Start-stop confirmation timed reasoning device.

Claims (1)

[Claims] 1. An operation control device for a private power generation facility that supplies power to a load in parallel with a commercial power system and a private power generator or a plurality of private power generators, and a load power calculation device for detecting the load power and a load power calculation device. A load power change detector that detects a slope of change, a start power setter that sets a load power that starts a predetermined private generator, a stop power setter that sets a load power that stops the private generator, and A starting power deviation calculator for calculating the deviation between the set power of the starting power setting device and the load power, a stopping power deviation calculator for calculating the deviation between the setting power of the stopping power setting device and the load power, and time detection for detecting the current time And that the load power exceeds the set value set by the starting power setter or the load power falls below the set value set by the stop power setter. A start stop confirmation time limit reasoner that calculates a start confirmation time limit to confirm and a stop confirmation time limit, and an operation stop controller that controls the operation stop of the private power generator. The slope of the power change and the output of the start power deviation calculator and the output of the stop power deviation calculator are input, and the state of the change of the load power at each time is inferred from the predetermined inference rules specific to the private power generation facility, and the start is performed. An operation control device for a private power generation facility, which is configured to calculate a confirmation time period and a stop confirmation time period and control the operation stop of the private power generator by the start confirmation time period and the stop confirmation time period.