JPS6341902A - Controller for power plant equipment - Google Patents

Abstract

PURPOSE:To securely eliminate unnecessary operation as to control over power plant equipment by detecting a target value being written in a controller on a target value reception side. CONSTITUTION:When the target value xk is varied and set by a target value setter 1, the target value xk varies with time and is different from an originally set target value such as a transiently zero value, so it is different from a target value sampled by a sampling circuit 7 and a comparing circuit 9 and a discriminating circuit 10 detect the mean value found by a mean value arithmetic circuit 8 being different from the current input target value xk. In this case, the target value is being rewritten and the discriminating circuit 10 inputs the feedback value xa of the power plant equipment 3 as it is as a final output target value xr; and a controller 2 operates so as to maintain and controls the current state of the power plant equipment 3, so that output pulses 3 are locked as they are.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power plant equipment control device that performs feedback control in response to a target value in power plant equipment.

[Prior Art] FIG. 2 is a block diagram showing a conventional power plant equipment control device. In the figure, 1 is a target value setting device as a target value setting means that can change and set the target value, and 2A is a target value setting device, which will be described later. 3 is the target power plant equipment (generator G, etc.) to be adjusted and controlled by the control device 2A; 4 is the power plant equipment 3 from the control table @ 2A; This is an output pulse as a control signal given to.

Note that xk is the target value output from the target value setter 1 to the control device 2A, and xa is the target value output from the power plant equipment 3 to the control table [1W2A
This is the feedback value that is fed back to the

On the other hand, 5 is a subtracter that compares the target value xk and the feedback value Xa to find and output the deviation value (xk - xa), and 6 is a subtracter that outputs the deviation value from the subtracter 5 as zero. This control signal generator 6 is a control signal generating circuit as a control means for controlling the power plant equipment 3 so that
The width and interval of the output pulse 4 are changed and outputted depending on the magnitude and sign of the deviation value (xk-xa) from the subtracter 5.

Next, the operation will be explained. The control device 2A controls the power generation so that the deviation value (xk−xa) between the target value xk set by the target value setting device 1 and the feedback value xa from the power plant equipment 3 that is subject to adjustment control approaches zero. Outputs an output pulse 4 to the device 3.

In such a control device 2A, the larger the deviation value (xk-xa) from the subtracter 5, the more output pulses 4 are outputted from the control signal generator 6 to perform greater increase/decrease control on the power plant equipment 3. It has the characteristic of being

If the value of the feedback value xa is small and the deviation value (xk-xa) is large with respect to the target value xk, the output pulse 4 from the control signal generator 6 of the control device 122A has a long pulse width and a short pulse interval. However, the deviation value (
As xk-xa) becomes smaller, the output pulse 4
is changed so that the pulse width is short and the pulse interval is long.

[Problems to be Solved by the Invention] Since the conventional power plant equipment control device is configured as described above, when operating the target value setter 1, for example, the target value can be changed from a value of 100 to a value of 250. When increasing the value, if the value changes instantaneously from 100 to 250, it will follow the change in the target value without any problem, but if an intermediate value (for example, zero) occurs between the old setting value and the new setting value. If there is an intervening value, the control device 2A may temporarily read the intermediate value as the target value and perform unnecessary operations in controlling the power plant equipment 3. In other words, in a method where the target value is once canceled to zero as in this example, when changing the target value,
An unnecessary control operation occurs in which the control device [2A outputs a reduced output and then increases the output again.

In order to eliminate these unnecessary operations, "Target value rewriting"
An external signal is given to the control device 2A, and the control device 12
Measures have been taken to temporarily lock the control operation of A, but
In many cases, it was impossible to generate a signal indicating 'target value rewriting in progress' externally to the control device 2A.

This invention was made in order to solve the above-mentioned problems, and it is possible to detect that the target value is being rewritten inside the control device that is the target value receiving side, and to control the power plant equipment. An object of the present invention is to obtain a power plant equipment control device that reliably prevents the above unnecessary operations from occurring.

[Means for solving the problem] The power plant equipment control device according to the present invention includes a target value setting means for changing and setting a target value, and a target value from the target value setting means and the power plant equipment. Comparing means for comparing the feedback value and outputting the deviation value, and control means for controlling the power plant equipment so that the deviation value output from the comparing means becomes zero, A target value sampling means for sampling the target value and an average value calculating means for calculating the average value of the sampled values from the target value sampling means are provided.

prohibition means for comparing the average value calculated by the average value calculation means and the target value from the target value setting means and prohibiting feedback control based on the target value from the target value setting means if these values differ; It has been established.

[Function] In the power plant equipment control device according to the present invention, the target value from the target value setting means is sampled by the target value sampling means, and the average value of the sampled values is calculated by the average value calculation means. The average value from the calculation means and the target value from the target value setting means are compared in the prohibition means, and if these values differ, feedback control is prohibited based on the target value from the target value setting means.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
FIG. 1 is a block diagram showing a power plant equipment control device according to an embodiment of the present invention. In FIG. 1, 1 is a target value setting device as a target value setting means that can set the target value by changing it, and 2 is a subtraction device described later. Vessel 5. Control signal generator6. Sampling circuit 7. A control device consisting of an average value calculation circuit 8 and a feedback control inhibiting means 11; 3 is power plant equipment (generator G, etc.) to which the control device 2 performs adjustment control; 4 is a link from the control device 2 to power plant equipment 3; This is an output pulse as a control signal given. Note that xk is a target value output from the target value setter 1 to the control device 2, and xa is a feedback value fed back from the power plant equipment 3 to the control device 2.

On the other hand, 5 is a subtracter as a comparison means for comparing a target value xr outputted from a feedback control inhibiting means 11 and a feedback value xa, which will be described later, to obtain and output a deviation value (xr-xa), and 6 is the same. This control signal generator 6 is a control signal generation circuit serving as a control means for controlling the power plant equipment 3 so that the deviation value output from the subtractor 5 becomes zero.
The width and interval of the output pulse 4 are changed and outputted depending on the magnitude and sign of the deviation value (xr-xa) from the subtracter 5.

Furthermore, in this embodiment, 7 is a sampling circuit as a target value sampling means for receiving the target value xk from the target value setter 1 and sampling the target value xk;
is the average value i of the sampling values from the sampling circuit 7
Average value calculation circuit as average value calculation means for calculating 9
10 is a comparison circuit that compares the average value from the average value calculation circuit 8 with the current input target value xk directly input from the target value setting device 1; 10 is a discrimination circuit;
is the average value or target value −x based on the signal from the comparator circuit 9
If k is the same value, the final output target value xr is set to the target value xk
If different, the final output target value xr is set as the value of power plant equipment 3.
This prohibits feedback control based on the target value xk as the feedback value xa from the target value xk.

Reference numeral 11 denotes feedback control inhibiting means, which is comprised of the comparison circuit 9 and the discrimination circuit 10 described above.

Next, the operation will be explained. When the target value xk is not changed by the target value setter 1, the target value xk is constant, so all the target values sampled by the sampling circuit 7 (however, the number of samplings is n times at intervals of time Δ) are This value becomes the same value as the average value calculated in the average value calculation circuit 8 or the current input target value xk from the target value setting device 1.

Therefore, this current input target value xk is outputted from the discrimination circuit 10 to the subtracter 5 as the final output target value xr.

Then, in the subtracter 5, as in the conventional case, the final output target value xr and the feedback value xa from the power plant equipment 3 side are input.
A deviation value (xr-xa) from

On the other hand, when the target value xk is changed and set by the target value setting device 1, the target value xk changes over time and transiently takes on a value different from the target value that should be set, such as a value of zero. Therefore, the target value sampled by the sampling circuit 7 is different, and the comparison circuit 9 and the discrimination circuit 10 detect that the average value i obtained by the average value calculation circuit 8 is different from the current input target value xk. be done.

Therefore, in this case, the target value is being rewritten.
The discrimination circuit 1o determines the power plant equipment 3 as the final output target value xr.
The control device 2 inputs the feedback value xa from the target value setter 1 as it is and controls the power plant equipment 3 to maintain the current state (that is, to prohibit feedback control based on the target value xk from the target value setting device 1). The control device 2 then locks the output pulse 4 in its current state.

This control operation for maintaining the current status continues until a new target value is set, a suitable amount of time has elapsed, and the average value i from the average value calculation circuit 8 and the current input target value xk become the same value as described above. It will be done.

In this way, according to the present embodiment, even if the target value xk itself changes transiently when rewriting the target value xk, there is no need to add a signal indicating "target value is being rewritten" from the outside.
In the control bag rIi2, follow-up control is performed only from the old target value to the new target value, and it is possible to reliably prevent unnecessary operations of the power plant equipment 3 due to rewriting of the target value.

Note that in the above embodiment, the subtracter 5. Control signal generator6.
Sampling circuit 7. Comparison calculation circuit 8 Comparison circuit 99 Discrimination circuit 10 is configured as an analog device and each function is made up of independent circuits, but these circuits can also be realized as a digital device using a microcomputer with a series of software. In this case as well, the same effects as in the above embodiment can be achieved.

[Effects of the Invention] As described above, according to the present invention, in a control device that performs feedback control of power plant equipment based on the target value transmitted from the target value setting means, the target value accompanying the set value rewriting operation is target value sampling means so that the control device controls the power plant equipment to maintain the current state when changing the power plant equipment;

Since we have added an average value calculation means and a prohibition means, even if the target value itself changes transiently when rewriting the target value, it is possible to receive an external message saying "Target value is being rewritten" (without adding "g"). The control device side can perform control that follows only the frontage target value and the new target value, which has the effect of reliably preventing unnecessary operations of power plant equipment due to target value rewriting.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a power plant equipment control device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional power plant equipment control device. In the figure, 1 - target value setting device as target value setting means, 3 - power plant equipment, 5 - subtracter as comparison means, 6 -
7. A sampling circuit as a target value sampling means. 8. An average value calculation circuit as an average value calculation means. 11. A feedback control inhibition means as an inhibition means. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A target value setting means that can set the target value by changing it; a comparison means that compares the target value from the target value setting means with a feedback value from the power plant equipment and outputs a deviation value; control means for controlling the power plant equipment so that the deviation value output of the target value becomes zero; target value sampling means for sampling the target value from the target value setting means; An average value calculation means for calculating an average value is provided, and the average value calculated by the average value calculation means and the target value from the target value setting means are compared, and if these values are different, the target value is set. A power plant equipment control device, characterized in that a prohibition means for prohibiting feedback control based on a target value from a setting means is provided.