JP3529807B2 - Speed control device of governor in turbine generator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control device for a governor in a water turbine generator. 2. Description of the Related Art Generally, a speed control device for controlling a governor of a water turbine generator in a hydroelectric power plant has a circuit configuration as shown in FIG. In FIG. 3, the speed detection signal of the turbine generator 3 detected by the speed detector 2 is subtracted by the subtractor 4 from the speed set value set by the speed setter 1, and the speed deviation is input to the PID controller 5. I do. [0003] The PID controller 5 calculates a guide vane opening command value based on the speed deviation, and inputs it to the upper limiter 6 as a control output. The upper limiter 6 limits the upper limit of the control output based on the upper limit set value set by the load limiter 7 and outputs a guide vane opening command value of the water turbine 8. The guide vane opening command value is input to a subtractor 9, where the current guide vane opening detected by the guide vane opening detector 10 is subtracted from the guide vane opening command value, and the opening is subtracted. The guide vane drive unit 11 is controlled based on the degree deviation to open and close the guide vanes of the water turbine 8. Therefore, when the guide vanes open and close, the flow rate of the water turbine changes, so that the speed of the water turbine generator 8 is controlled. Next, a configuration of a general excitation circuit of the water turbine generator will be described with reference to FIG. In FIG. 4, reference numeral 3 denotes a turbine generator. The output terminal of the turbine generator 3 is connected to a system bus (not shown) through a main circuit 21. An excitation controller 23 is connected to a main circuit 21 of the turbine generator 3 via an instrument transformer 22.
Are connected, and the excitation control device 23
An excitation pulse is applied to the thyristor rectifier 24 provided in the excitation circuit of (1) to perform excitation control so that the output voltage of the water turbine generator 3 becomes the rated voltage. [0007] The thyristor rectifier 24 is connected to the turbine generator 3.
A generator voltage is generated by applying an excitation current corresponding to the gate control by the ignition pulse to the generator excitation winding 3F to excite the generator from the anode power supply provided by the excitation transformer 25 connected to the main circuit 21 of the generator. Let it. In this case, when the generator voltage is generated, the excitation switch 26 is turned on by a synchronous speed signal (not shown), the initial excitation switch 27 is turned on, and the storage battery 2 is turned on.
The generator voltage is generated by applying an excitation current to the generator excitation winding 3F through the step 8. Note that the initial excitation switch 27 is opened when the generator voltage becomes equal to or higher than a certain value. Here, the operation of the speed control device of the governor in the water turbine generator configured as described above will be described with reference to a time chart shown in FIG. Now, when the turbine generator start command 31 is issued, the load limit setting device 7 shown in FIG. As a result, the speed of the turbine generator 3 is stopped and zero with respect to the speed set value of the speed setting device 1, so that the guide vane opening is controlled to be open, and finally the guide vane opening is reduced in load. Since the start opening degree 32 is controlled by the setting device 7, the turbine generator 3 is controlled toward the rated speed. When the speed of the turbine generator 3 increases, the excitation switch 26 shown in FIG. 4 is turned on in order to generate a generator voltage. It is thrown in when the speed reaches%. In addition, the speed increases as the turbine generator 3 approaches the rated speed.
The guide vane opening is controlled to the no-load opening by the degree deviation and PID controller 5 so that the turbine generator 3 has the rated speed. [0011] However, when the turbine generator is started by such a speed control device of the governor in the conventional turbine generator, as can be seen from the time chart shown in FIG. When the excitation switch 26 is turned on and the generator voltage starts to be generated, the speed of the turbine generator is reduced due to excitation loss, and finally the turbine generator 3 is rated at the rated speed by the speed deviation and the PID controller 5. The guide vane opening is controlled so that The effect of the excitation loss appears remarkably in a recent small hydroelectric power plant where the inertia of the turbine generator is small, and after turning on the excitation switch 26 as shown in the turbine generator speed curve shown in the time chart of FIG. , The speed may decrease. As a result, the water turbine generator 3 not only becomes in a state close to the low frequency overexcitation, but also has a problem that the time required to reach the rated speed becomes long. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to improve the speed reduction due to the effect of excitation loss after turning on an excitation switch even in a water turbine generator having a small inertia, and to reduce the rated speed. It is an object of the present invention to provide a speed control device of a governor in a water turbine generator capable of shortening a time required to reach the speed. In order to achieve the above object, the present invention provides a guide vane opening degree command for a water turbine based on a deviation between a speed setting value of a generator having an exciting winding and a speed detection signal. determined value, gradation in the guide vane opening command value and the water wheel guide vane opening detection signal to adjust the water turbine guide vane opening on the basis of a deviation between the water turbine generator for controlling the speed of the water turbine generator with the speed control device for a speed machine, the
Exciting means for exciting an exciting winding of a generator, and the exciting means
Means for determining when the excitation winding of the generator is excited by
When the excitation winding of the generator is excited by the determination means,
Excitation loss compensating means for generating, as excitation loss compensation signal, a bias signal attenuated by a preset time constant when is determined.
And an excitation loss compensation signal output from the excitation loss compensation means.
Adding means for adding the speed set value of the turbine generator to
It is provided to compensate for excitation loss of the turbine generator. In the speed control device of the governor in the water turbine generator having such a configuration, when the power generator is excited when the water turbine generator is started, the excitation output from the excitation loss compensating means is provided. The loss compensating signal is added to the speed setting value of the turbine generator, and the guide vane opening command value is obtained based on the signal compensated for the response time of the reduction in the rotation speed of the turbine generator due to the excitation loss, thereby obtaining the guide vane opening of the turbine. Is adjusted, the speed reduction due to the effect of the excitation loss is improved, and the time until the generator reaches the rated speed can be shortened. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration example of a speed control device of a governor in a water turbine generator according to the present invention. The same parts as those in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted. State. In this embodiment, as shown in FIG. 1, a turn-on signal of an excitation switch 26 (shown in FIG. 4) is supplied to a single shot timer 12, and an output signal of the single shot timer 12 is supplied to an AND circuit together with a bias signal. 13 and the output signal of the AND circuit 13 is supplied to a subtractor 14. The subtracter 14 obtains a deviation between an output signal of the AND circuit 13 and an output signal obtained by integrating the output signal of the subtractor 14 by an integrator 15 and attenuates the difference by a predetermined time constant. It outputs an excitation loss compensation signal. The excitation loss compensation signal output from the subtractor 14 is supplied to an adder 16 to be added to the speed set value set by the speed setter 1, and the output is supplied to the subtractor 4 as a speed set signal. It is assumed that. In the speed control device of the governor in the water turbine generator having such a configuration, when the water turbine generator 3 is started, the excitation switch 26 is turned on, and the turning on signal is input to the single shot timer 12. A pulse signal having a fixed time width is input to the AND circuit 13. The AND circuit 13 supplies a bias signal to the subtractor 14 for a pulse width time in response to the input of the pulse signal. The integrator 1 integrates the bias signal and the output signal of the subtractor 14.
The deviation from the output signal of No. 5 is obtained, and the output is given to the adder 16 as an excitation loss compensation signal attenuated by a preset time constant, and is added to the speed set value set by the speed setter 1. Therefore, even if the excitation of the generator causes an effect of the excitation loss on the water turbine, it corresponds to the loss.
Since the excitation loss compensation signal is added to the speed set value to control the governor, the target speed of the turbine generator becomes apparently higher,
It is possible to prevent a decrease in speed after the generator is excited. FIG. 2 is a time chart showing the operation of the speed control device of the governor in the turbine generator. Here, in comparison with the conventional time chart shown in FIG. 5, the speed setting value is constant (rated speed) in the related art, whereas in the present embodiment, the speed setting device is set when the excitation switch 26 is turned on. The guide vane opening is controlled by the speed setting signal obtained by adding the excitation loss compensation signal to be subtracted from the set value set by the time constant set in advance, so that the opening of the guide vane in the closing direction is set. The closed time is reduced by the time corresponding to the time constant, and the closing amount is also reduced, so that it is possible to improve the speed reduction of the water turbine generator 3 due to the influence of the excitation loss after the excitation switch is turned on. In the above embodiment, the excitation loss compensation for the speed setting value is performed at the closing timing of the excitation switch. However, if the excitation loss compensation is performed when the turbine generator has an arbitrary speed, the excitation loss compensation is performed. It is possible to improve the stabilization time until the rated speed peculiar to the PID is obtained even with the turbine generator which is less affected by the loss. As described above, according to the present invention, even in a small hydroelectric power plant having a small inertia of a turbine generator, it is possible to improve the speed reduction due to the effect of the excitation loss after the excitation switch is turned on. It is possible to provide a speed control device of a governor in a water turbine generator that can be used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a speed control device of a governor in a water turbine generator according to the present invention. FIG. 2 is a time chart for explaining the operation of the embodiment. FIG. 3 is a block diagram showing a speed control device of a governor in a conventional water turbine generator. FIG. 4 is a connection diagram showing a configuration of a general excitation circuit of the water turbine generator. FIG. 5 is a time chart for explaining the operation of the conventional device. [Description of Signs] 1... Speed setting device, 2... Speed detector, 3.
4 ... subtractor, 5 ... PID controller, 6 ... upper limiter, 7 ... load limiter, 8 ... water wheel, 9 ... subtractor, 10 ... guide vane opening detector, 11 ... Guide vane drive unit, 12 Single shot timer, 13
... AND circuit, 14 ... subtractor, 15 ... integrator, 1
6 ... Adder.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F03B 15/00-15/22

Claims (1)

(57) [Claims 1] A guide vane opening command value of a water turbine is determined from a deviation between a speed set value and a speed detection signal of a generator having an excitation winding, and the guide vane opening is determined. the speed control device for a speed governor in water turbine generator by adjusting the water turbine guide vane opening on the basis of a deviation between the guide vane opening detection signal of the command value waterwheel to control the speed of the water turbine generator, wherein Excitation means for exciting the excitation winding of the generator, and the excitation
Means for determining when the excitation winding of the generator is excited by the means
Step and the excitation of the excitation winding of the generator by this means of determination.
When the time is determined, an excitation loss compensating means for generating a bias signal attenuating with a preset time constant as an excitation loss compensating signal, and an excitation loss compensating signal outputted from the excitation loss compensating means.
Addition means for adding the speed set value of the turbine generator to the number
A speed control device of a governor in the turbine generator , wherein the excitation loss of the turbine generator is compensated for.