JPH0261302A - Turbine control device - Google Patents

Abstract

PURPOSE:To enable switching of a mode without a plant fluctuation by providing a switching means to selectively feed a permanent speed variation gain output to an adder on the load setter side or an adder on the load limiter side according to a load setter follow-up mode and a load limiter follow-up mode. CONSTITUTION:A turbine control device 22 determines a load signal PG by adding a load set signal from a load setter 34 and a permanent speed variation gain output from a computer 33 by means an adder 35. The load signal is compared with a load limit value PL set by a load limiter 36 by means of a lowland priority circuit 37, and a signal for the one, being lower, of the two values produces a final load signal P. By means of the load signal P, a lower limit valve 3 and other valve are controlled through load distributors 38 and 42. In this case, a change-over switch 58 is situated to the output end of a permanent speed variation limiter 36, and an adder 59 is situated to the output end of the load limiter 36. An output from a permanent speed variation computer 33 is selectively added to an output from the load setter 34 or an output from the load limiter 36.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a turbine control device, and in particular to an electrohydraulic governor.
The present invention relates to means for automating switching between load limiter tracking and load setter tracking and significantly shortening the switching time in a turbine control system that employs EHG.

[Conventional technology]

In a conventional turbine control device, an automatic boiler control device (automatic boiler control device) is used.
ler) to operate the load setter and change the operation mode from the state in which the load setter follows the load setter to the operating mode in which the operating end of the automatic boiler control device follows the load setter and the load setter follows the load limiter. After lowering the load limiter to the load setting position, the set value of the load setter was raised and the operation mode was switched. At this time, the operating end of the automatic boiler control device is also switched to the load limiter side in accordance with the above operation.

[Problem to be solved by the invention]

In recent years, the operating rate of atomic couplers has increased and the specific gravity of atomic couplers has increased, so the Da of thermal power plants has increased.
There is a trend towards 5tart up 5hut down. This DSS system is required to shorten startup time as much as possible while maintaining plant stability.

In the conventional example above, the output of the load limiter was lowered once to the load setting position, and then the load setter was raised to switch between the load setter follow-up mode and the load limiter follow-up mode.
There was a drawback that switching took at least 2 to 3 minutes.

In addition, the operating end of the automatic boiler control device also switches to the load limiter side in response to the above operations, which makes the operation complicated and there is a risk of operational errors or drastic changes in the operating conditions on the automatic boiler control device side. .

An object of the present invention is to provide a turbine control device that can quickly and accurately switch between a load setter follow-up mode and a load limiter follow-up mode without significantly affecting the automatic boiler control device.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a load setting device that outputs a load setting signal, and multiplies the speed deviation amount between the set speed of the speed setting device and the actual speed signal from a turbine speed detector by a speed regulation rate. means for calculating a speed adjustment rate gain output; a first adder for adding the load setting signal and the speed adjustment rate gain output to output a load signal; and a predetermined follow-up @ for the final load signal.
a load limiter that outputs a load limit value signal based on a value added with a set value; and a low value priority circuit that selects a lower signal from the load signal and the load limit value signal and outputs it as the final load signal. and a second adder that adds the output signal of the load limiter and the speed regulation rate gain output and outputs the result to the low value priority circuit in the turbine control device that can switch between a load setter follow mode and a load limiter follow mode. and switching means for selectively supplying a speed regulation rate gain output to a first adder or a second adder according to a load setter follow-up mode or a load limiter follow-up mode. It is something to do.

It is desirable to provide means for prohibiting the operation of the switching means when the speed deviation amount is equal to or greater than a predetermined value.

[Effect]

In the present invention, the switching means selectively supplies the speed regulation rate gain output to the load setter-side adder or the load limiter-side adder according to the load setter follow-up mode and the load limiter follow-up mode. This eliminates the need to go through the steps of gradually decreasing the following width on the following side, once matching the outputs of the load limiter and load setter, and then gradually increasing the output on the opposite side. For example, it is possible to switch between the two almost instantly within 0.1 seconds.

At that time, the automatic boiler control device constantly exchanges control signals with the load setting device, so the conditions on the automatic boiler control device side do not change suddenly, and operation becomes simple. .

Further, when the speed deviation amount is equal to or greater than a predetermined value, a means for prohibiting the operation of the switching means is provided, and sudden changes in control conditions on the turbine side are also prevented, thereby preventing disturbances to the power system.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

Figure 4 shows an overview of the turbine control system.

The steam generated in the boiler 1 is passed through the main steam stop valve 2. Adjustment valve 3
and is supplied to the steam turbine 10.

The turbine 10 typically includes a high pressure turbine 11, an intermediate pressure turbine 12, and a low pressure turbine 13.

After the steam does work in the high pressure turbine 11, it passes through the reheater 16.
The temperature of the water is raised again, passes through the reheat steam stop valve 17 and the intercept valve 18, and then works in the intermediate pressure turbine 12 and the low pressure turbine 13, and becomes water in the condenser 19. The energy of the steam is converted into rotational motion by the turbine 10, which turns the generator 20 and supplies power to the grid.

The turbine control device 22 controls the rotation speed, load, etc. of the turbine 10. The rotation speed of the turbine is detected by counting the rotation speed of a gear 14 attached to the rotation shaft of the turbine 1o using a speed detector 15. Additionally, the load on the turbine is detected by the power converter 21. These detection signals are sent to the input section 23 of the turbine control device 22 and processed by the calculation section 25. The computing unit 25 operates an intercept valve 18. to control the rotation speed, load, etc. of the turbine. The valve position of the control valve 13 and the like is calculated, and a signal is created to drive the response valve to that position. What is the valve drive signal?

The signal is sent from the output section 24 to a counter drive unit such as the intercept valve displacement unit 9 and the adjustment valve drive unit 7 to drive the respective valves. On the other hand, the movement of the valve is detected by the intercept valve position detector 8. It is detected by a position detector such as the control valve position detector 6, and is fed back to the input section 23 of the turbine control device 22 to localize the position of the valve.

A part of a conventional configuration example of the turbine control device 22 is shown in FIG. 5. The turbine rotation speed is detected by a speed detector 15. As shown in FIG. The detected actual speed signal N is compared with the set speed signal N0 set by the speed setter 31 in the comparator 32, and the deviation amount ΔN (= N 0 - N) is sent to the adjustment and ratio calculator 33. Reportedly. The adjustment rate calculator 33 multiplies the preset speed adjustment rate δ by a gain corresponding to the adder 35.
tell to.

The adder 35 receives the signal P set by the load setting device 34.

is added to create the load signal PG. The speed adjustment rate δ is the speed (
When the generator is connected to the power grid and operating synchronously,
Corresponds to the grid frequency. ) is the value that indicates the percentage deviation from the set value (rated value) at which the total load will be changed. For example, a 5% adjustment rate means that if there is a speed fluctuation of 5%, the
It means changing the % load. i.e. 100%
Assuming that the system frequency (speed) increases by 5% during load operation, the load will be reduced to 0% in order to maintain the frequency at actual operation.

The load signal PG is compared with the load limit value PL set by the load controller 36 in a low value priority circuit 37, and the lower signal becomes the final load signal P. The load signal P is transmitted to the load distributor 3
8.42 etc. are distributed according to the amount of answering, and the opening degree (flow rate) of answering is determined.

Control the position of the answer. In FIG. 5, the following parts only show those for the control valve 3, and the others are omitted, but they have the same structure. The output of the load distributor 38 is compared with a valve position feedback signal by a comparator 39, and the deviation signal is converted into a valve drive signal Sv by an adjustment controller 4o, and the valve drive unit 7 controls the opening degree of the control valve 3. adjust.

The opening degree of the regulating valve 3 is detected by the position detector 6, passed through the 1-position converter 41, fed back as the opening degree detector U, and provided to the comparator 39. Note that when the load signal P0 is given priority in the low value priority circuit 37, it is called speed-governing operation, and when the load limit value PL is given priority, it is called load limit operation.

When performing load operation based on a signal from the automatic boiler control device 26, the automatic boiler control device 26 drives the load setting device 34 to perform load operation. At this time, the load setting device 34 is selected by the switch 5o at the operation end of the turbine control device 22, and the signal is sent to the switch 51 as a feedback signal to the automatic boiler control device 26.

The output P of the load setting device 34. send in.

In such a control system, from a state in which the load limiter 36 follows the load setting device 34, the automatic boiler control device 2
First, a conventional operating method for switching the operating end of No. 6 to the load limiter 36 will be described.

FIG. 6 shows the switching operation.

When the load limiter 36 follows the load setter 34 (
t≦to), the switch 50. The switch 51 and the switch 52 are turned on, and the output α of the tracking width setter 54 is added to the output of the low value priority circuit 37, and the output PL of the load limiter 36 follows as PL=PG+α=p+α.

The switching proceeds in the following steps.

1. Gradually reduce the output α of the load limiter follow-up width setter 54 to O.

2. At t□ when the output PL of the load limiter 36 decreases and becomes PL=PG, the switch 50 is turned off, the switch 51 is turned off, the switch 52 is turned off, and the switch 53 is turned on.

3. The output of the load setting device 34 is calculated by adding the output α of the load setting device tracking width setting device 55 to the output P of the low value priority circuit 37.
Follow L=PG+α=P+α.

As described above, the switching operation was complicated. In addition, load fluctuations due to errors in operating procedures or incorrect selection of operating end feedback signals are predicted.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

The present invention has a changeover switch 5 at the output end of the adjustment rate calculator 33.
8, an adder 59 is added to the output of the load limiter 36, and a method is adopted in which the output of the adjustment rate calculator 33 is selectively added to the output of the load setting device 34 or the output of the load limiter 36. It is something.

The present invention focuses on the fact that the load signal PG is the sum of the output P of the load setting device 34 and the speed deviation amount ΔN (=N, -N) multiplied by the speed regulation rate gain, and sets the load. The switching from device tracking to load limiter tracking is performed by switching ΔN, that is, switching the speed regulation rate gain output PN.

The switching procedure will be explained with reference to FIG.

The selector switch 58 is set to the load limiter follow-up mode at to. When the selector switch 58 is set to this mode, PN is removed from the input of the adder 58, and P G =P. On the other hand, the output PNL of the adder 59 is PNL=PL+
It becomes PN.

With the above operations, only the switch 58 can be operated.

This is the same function as conventional load limiter tracking.

In the invention shown in FIG. 1, PN is added to the output of the load limiter 36, but the same effect can be obtained even if PN is added to the adder 56.

Furthermore, if the switch 58 is turned on while PN is fluctuating, load fluctuation will occur, so as shown in FIG.
Just add a function to check the value of N (or PN). That is, the A N D circuit 61 checks the switching instruction signal from a control console (not shown) and the output from the comparator 6o that determines the condition that the absolute value of the speed deviation ΔN is smaller than the constant value α, and then calculates ΔN( or PN)
Switching is possible only when the value is small (a value that does not cause fluctuations in the plant).

By employing this means, it is possible to switch between the load setter follow-up mode and the load limiter follow-up mode without causing fluctuations on the power system side.

〔Effect of the invention〕

According to the present invention, the switching operation is easy, there is no plant fluctuation at the time of switching, and the turbine control is capable of switching between the load setter follow-up mode and the load limiter follow-up mode almost instantaneously, for example, within 0.1 seconds. A device is obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a main part of an embodiment of a turbine control device according to the present invention, FIG. 2 is a diagram explaining the operation of the first embodiment, and FIG. FIG. 4 is a diagram showing an overview of a turbine control system to which the present invention is applied; FIG. 5 is a diagram showing the configuration of an example of a conventional turbine control device.
FIG. 6 is a diagram illustrating the operation of the example shown in FIG. DESCRIPTION OF SYMBOLS 1...Boiler, 2...Main steam stop valve, 3...Adjustment valve, 4...Main steam stop valve position detector, 5...Main steam stop valve drive unit, 6...Adjustment Valve position detector, 7.
... Adjustment valve drive unit, 8... Intercept valve position detector, 9... Intercept valve drive unit, 10.
...Steam turbine, 11...High pressure turbine, 12...
・Intermediate pressure turbine, 13...Low pressure turbine, 14...
Gear, 15... Speed detector, 16... Reheater, 17
... Steam stop valve, 18 ... Intercept valve, 19.
... Condenser, 20 ... Generator, 21 ... Power converter, 22 ... Turbine control device, 23 ... Input section, 2
4... Output section, 25... Calculation section, 26... Automatic boiler control device, 31... Speed setter, 32... Comparator, 33... Adjustment rate calculator, 34... Load setting device, 3
5... Adder, 36... Load limiter, 37... Low value priority circuit, 38... Load distributor, 39... Comparator, 40... Adjustment controller, 41...・Position transducer, 42
...Load splitter. 43...Comparator, 50, 51, 52.53...Switch, 54...Load limiter tracking width setter, 55...
Load setting device following width setting device, 56, 57. 59... Adder, 58... Switch, 60... Comparator, 61...
・AND circuit.

Claims (1)

[Claims] 1. Speed adjustment rate gain multiplied by the speed adjustment rate by the speed deviation between the load setter that outputs the load setting signal, the set speed of the speed setter, and the actual speed signal from the turbine speed detector. means for calculating an output; a first adder that adds the load setting signal and the speed regulation rate gain output and outputs a load signal; and load limiting based on the value obtained by adding a predetermined follow-up width setting value to the final load signal. A load limiter that outputs a value signal, and a low value priority circuit that selects a lower signal from the load signal and the load limit value signal and outputs it as the final load signal, and has a load setter follow-up mode and load limit. a second adder that adds the output signal of the load limiter and the speed regulation rate gain output and outputs the result to the low value priority circuit; A turbine control device comprising switching means for selectively supplying the speed regulation rate gain output to the first adder or the second adder depending on a mode and a load limiter following mode. 2. The turbine control device according to claim 1, further comprising means for prohibiting operation of said switching means when said speed deviation amount is equal to or greater than a predetermined value.