JPS63240398A - Output controller for generator - Google Patents

Abstract

PURPOSE:To prevent the output of a generator from varying by adding a frequency deviation to the adder of an output controller. CONSTITUTION:An adder 5a' of an output controller 5 calculates the deviation P of an output command value P0, the output PG of a generator 2 and a frequency deviation f. The deviation P is amplified by an amplifier 5b, and output as the output P' of the controller 5. An adder 6b adds the output P' from the controller 5 and the deviation f, and outputs the added value as the control value of the generator 2. Thus, the variation in the generator output can be suppressed when a generator failure defect or a load failure defect occurs, and a frequency variation can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a generator output control device that controls the output of a generator supplying power to an electric power system.

[Conventional technology]

A generator that supplies power to a power system is equipped with a generator output control device for adjusting the output of the generator to a predetermined value. - Such a generator output control device will be explained using figures.

FIG. 4 is a block diagram of a conventional generator output control device. In the figure, 1 is a power system, 2 is a generator that supplies power to the power system 1, and 3 is another generator that also supplies power to the power system 1. A detector 4 detects the output of the generator 2, and outputs a signal proportional to the output of the generator 2. 5 is an output control device that determines the output of the power generation a2, an adder 5a that calculates the deviation between the output command value sent from the central power dispatch center and the output signal of the detector, and an adder 5a that amplifies the output of the adder 5a. It is composed of an amplifier 5b.

This amplifier 5b is configured, for example, by a proportional-integral control system that combines proportional control and integral control. 6 is a speed governor that controls the rotational speed of the generator 2 to a constant value;
An amplifier 6a that amplifies the frequency deviation between the target frequency and the output frequency, an adder 6b that adds the output of the amplifier 6a and the output of the output control device 5, and an amplifier 6C that amplifies the output of the adder 6b. There is.

Output command value P of generator 2 output from the central power dispatch center
. is input to the adder 5a. On the other hand, the output P of power generation a2
6 is detected by the detector 4, and the detector 4 outputs a value proportional to the output PG (hereinafter, this value will be represented by the same symbol Pc) to the adder 5a. The adder 5a calculates the deviation ΔP (ΔP=Po Pc) between the two, and this deviation ΔP is amplified by the amplifier 5b, and the output ΔP of the output control device 5 is
It is output as P'.

Further, the frequency deviation Δf is amplified by the amplifier 6a and then inputted to the adder 6b, where it is added to the output ΔP' from the output control device 5, and this added value is amplified by the amplifier 6c, and then It is output from the speed governor 6 as a control wholesale value for the generator 2. With such a ficodopack control system, the output of the generator 2 is kept constant at the command value P0, and a stable output P0 is supplied to the power grid.

[Problem that the invention seeks to solve]

Now, for some reason, power system 1 is being disconnected at point F in the diagram.
Consider a case where another generator 3 that was supplying power to the generator 3 is disconnected. When such a situation occurs, the power system 2 will be short of the power PL that was being supplied by the other generators 3.

This shortfall is 1. The remaining generators connected to the power grid 2 share the power in a relationship determined by the impedance of the power grid 2, the impedance of each generator, and the like. Because of this sharing, the output of each remaining generator increases rapidly at the same time as generator 3 is disconnected, and
The frequency of power system 2 (ie, the frequency of the generator) begins to decrease. This decrease in frequency recovers over time and settles to the target frequency due to the effect of governor free and changes in the output command value from the central dispatch center due to automatic frequency control (in this case, an increase in the output command value). Let the frequency deviation Δf be 0. Such changes are shown in Figure 5(a).
, (b) and (c).

5(a), (b), and (c) are diagrams showing changes in the frequency deviation Δr, the output Pc of the generator 2, and the output ΔP' of the output control device 5 with respect to time, respectively, and the horizontal axis is the time. It's great. When disconnection of the generator 3 occurs at time t0, the output P of the power generation [2] immediately increases as shown in FIG. 5(b).

Also, the frequency of the power system l will also drop immediately, so that
The frequency deviation Δf also increases as shown in FIG. 5(a).

When the output P6 increases, the deviation ΔP increases in the feedback control system, and the output ΔP' of the output control device 5 also increases accordingly, as shown in FIG. 5(c). After that, the output P6 becomes the command value P due to the function of the feedback control system. Also, the output ΔP' approaches 0.

On the other hand, the command value P0 from the central power dispatch center is not changed immediately even if the generator 3 is disconnected, but after a period of time has elapsed, the command value P0 is changed at time t.
It is changed (increased) only when it reaches . As a result, the output Pc becomes a new command value P as shown in FIG. 5(b).

, and is finally made to match the new command value by the feedback system, and at the same time, the output ΔP' also becomes 0 as shown in FIG. 5(e). Furthermore, since the command value P0 includes a frequency control signal, the frequency deviation Δr also becomes zero eventually as shown in FIG. 5(a). In this way, stable power is supplied to the power system 2.

By the way, when the generator 3 is disconnected, it is desirable that the remaining generators increase their output to compensate for the output of the generator 3, and this increase in output suppresses frequency fluctuations. It is desirable to do so.

However, as shown in FIG. 5(b), in the conventional device, the output P, which had once increased, acts to decrease to the state before disconnection of the generator 3, which is the opposite of the desired state. There was a problem in that a situation like this occurred. Such a problem occurs not only when the generator 3 is disconnected and the generator a3 falls off, but also when a load falls off. It is clear that in a load shedding accident, an undesirable situation occurs in which the output, which has once decreased, increases, contrary to the generator falling accident.

The purpose of the present invention is to solve the above-mentioned problems of the prior art, and to easily control the increase or decrease of the output of a generator connected to the power grid in the event of an accident such as a generator falling off or a load shedding accident. It is an object of the present invention to provide a generator output control device that can control frequency fluctuations in an electric power system.

[Means for solving problems]

In order to achieve the above object, the present invention includes a calculation unit that calculates the deviation between the output command value for the generator and the generator output, and an output adjustment unit that adjusts the output of the generator based on the deviation. The generator output control device includes: a multiplier that multiplies a frequency deviation or a rate of change in the frequency deviation with respect to a target frequency of the generator by a predetermined value; and an adder that adds the value obtained by the multiplier to the deviation. It is characterized by having the following.

[Effect]

When a power system frequency deviates from the target frequency due to a generator falling accident, load falling accident, etc., the frequency deviation increases, and the absolute value of the value obtained by the multiplier also increases. When this value is added to the deviation between the output command value and the output, fluctuations in the generator output are suppressed, the generator output is maintained at a desired output, and frequency fluctuations are also suppressed.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a block diagram of a generator output control device according to an embodiment of the present invention. In the figure, parts that are the same as those shown in FIG. 4 are given the same reference numerals, and description thereof will be omitted. 5' is an output control device, which includes an adder 5a', an amplifier 5b, and an amplifier 5.
Consists of C. Amplifier 5c has a gain -K, and frequency deviation Δr is input to this amplifier 5C. therefore,
The output of the amplifier 5c becomes -K·Δf. The adder 5a' outputs the output command value PO1, the output PO1 of the generator 2, and the amplifier 5.
The output of c is input and a predetermined calculation is performed.

The difference between this embodiment and the device shown in FIG. 4 is that the amplifier 5C
Both are the same except that the adder 5a' is newly provided and the output of the amplifier 5c is also added in the adder 5a'.

Next, the operation of this embodiment is shown in FIGS. 2(a) and 2(b).

This will be explained with reference to a diagram of changes in frequency deviation Δf, generator output P, and output control device output ΔP' shown in (C). When the generator 3 drops out of the power system 1, the output P6 of the power generation a2 increases rapidly as described above, and the frequency of the power system also decreases, increasing the frequency deviation Δf. This frequency deviation Δf is input to the amplifier 5C, and the amplifier 5C outputs a signal -K·Δf. Adder 5a' outputs an output command value P. , the output signal PG of the generator 2, and the amplifier 5
The output signal -K·Δf of c is input and the following equation is calculated to obtain the deviation ΔP.

ΔP=Po PG + (K・Δf)・・・・・・(
1) As is clear from equation (1), the deviation ΔP is the sum of the output signal -K·Δf of the amplifier 5C (since the frequency deviation Δf is negative, the output signal -K·Δf is positive). This suppresses an increase in the negative direction. That is, as the generator 3 falls off, the output Pa of the generator 2 increases, and the value (p) in the above equation (1) increases.

-Pc) increases in the negative direction, this is suppressed by the output signal -K·Δf acting as a feedback amount of the feedback control system. Therefore, if the gain -K is selected to an appropriate value, the deviation ΔP can be suppressed to a value close to zero.

In this way, since the -deviation ΔP is suppressed, the output P6 of the generator 2, which increased due to the falling accident of the generator 3, is suppressed to the output that remains increased as shown in FIG. It will not drop as usual. As a result, the power shortage in the power system 1 caused by the falling accident of generator 3 can be sufficiently compensated for until a new output command value corresponding to the accidental falling accident is output from the central power dispatch center. can become.

Since the deviation ΔP is suppressed, the output Δ of the output control device 5'
Naturally, P' is also suppressed to a constant value close to 0 as shown in FIG. (a)
As shown in the figure, the frequency deviation Δf also does not decrease significantly. When a new output command value P0 is output from the central power dispatch center at time t, the output PG of the generator 2 converges to this value.

In this way, in this embodiment, the adder of the output control device has
Since the frequency deviation is input as the feedback amount of the feedback control system and added, it is possible to prevent the output of the remaining generators from decreasing, which once increased immediately after another generator falls off. It is possible to compensate for power shortages in the grid, and it is also possible to suppress a drop in the frequency of the grid. As a result, the power system can be quickly restored due to the generator falling accident.

FIG. 3 is a block diagram of a generator output control device according to another embodiment of the present invention. In the figure, parts that are the same as those shown in FIG. 5 is an output control device, which is composed of an adder 5a'', amplifiers 5b, 5c, and an amplifier 5d.The amplifier 5d has a gain of The ratio (rate of change) dΔf/dt is input manually. Therefore, the output of the amplifier 5d becomes -'·dΔf/dt. Output of 5C -K・Δf, and amplifier 5
dΔf/d t is input to the output − of d, and the deviation ΔP is calculated by the following calculation.

ΔP=P, −P, −K・Δf−K”・dΔf/dt
(2) The operation of this embodiment is similar to that of the previous embodiment, so the explanation will be omitted.

In this way, in this embodiment, since the frequency deviation and the rate of change of the frequency deviation are added as the feedback amount of the feedback control system, the same effect as the previous embodiment is achieved.

In addition, in the explanation of the above embodiment, the explanation is given as an example of a generator falling accident, but the explanation is not limited to this, and even if various other situations such as a load falling accident occur, the generator immediately after It is clear that the change in the output can be suppressed. Furthermore, the rate of change of the frequency deviation alone can be used as the feedback amount.

〔Effect of the invention〕

As described above, in the present invention, in the feedback control system in which the generator output is used as the feedback amount in response to the generator output command value, the frequency deviation and frequency deviation change rate are further used as the feedback amount. When an accident or the like occurs, the generator output can be maintained in a desired state, frequency fluctuations can be suppressed, and system recovery can be accelerated.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a generator output control device according to an embodiment of the present invention, and Fig. 2 (a), (b), and (C) show frequency deviation and power generation when the device shown in Fig. 1 is used. 3 is a block diagram of a generator output control device according to another embodiment of the present invention, and FIG. 4 is a block diagram of a conventional generator output control device. ,
Figure 5(a). (b) and (C) are diagrams showing changes in frequency deviation, generator output, and output of the output control device when the device shown in FIG. 4 is used. l...Electric power system, 2,3... Generator,
5.5'. 5#...Output control device, 5a, 5a", 5a"
...Adder, 5b, 5c, 5d...Amplifier, 6...Speed governor. Figure 1, Figure 2 to N1 3rd rXi

Claims (1)

[Claims] 1. A calculation unit that calculates the deviation between the output command value for the generator and the output of the generator, and an output adjustment that adjusts the output of the generator based on the deviation obtained by the calculation unit. A generator output control device comprising: a multiplier for multiplying a value related to the output frequency with respect to the target frequency of the generator by a predetermined value; and an addition means for adding the value obtained by the multiplier to the deviation. A generator output control device characterized by being provided with. 2. The generator output control device according to claim 1, wherein the value related to the output frequency of the generator with respect to the target frequency is a deviation between the target frequency and the output frequency. 3. The generator output control device according to claim 1, wherein the value related to the output frequency with respect to the target frequency of the generator is a rate of change in the deviation between the target frequency and the output frequency. 4. The generator output according to claim 1, wherein the value related to the output frequency with respect to the target frequency of the generator is a deviation between the target frequency and the output frequency, and a rate of change in this deviation. Control device.