JP3141572B2 - How to limit the output of a turbine generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for limiting the output (flow rate) of a turbine generator.

[0002]

2. Description of the Related Art A conventional method of limiting the output (flow rate) of a water generator will be described with reference to FIG.

In FIG. 4, reference numeral 10 denotes a flow control circuit;
3 is shared with the speed set by the speed setting switch 11.
The speed regulator sets the signal of the control amplifier 34 of the flow limiting circuit 30 is controlled, 14 deviation between the signal from the rigid restoration system 18, the speed detector 19 as a setting value and the feedback of the velocity regulator 13 Control amplifier input
5 is a governing mechanical system.

The input 16 receives the output of the adjusting mechanical system 15 and the set value of the load limit setting device 21 set by the load limit setting switch 20, and the signal from the speed control mechanical system 15 reaches the load limit set value. Output a flow rate Q proportional to the output until
A load limiting mechanism that outputs a flow rate Q limited to the set value when the load limit value is exceeded, and 17 is a water turbine generator rotated at the flow rate Q of the load limiting mechanism 16.

Reference numeral 30 (between AB) denotes a flow rate limiting circuit,
Is a limiter which receives a deviation ΔQ between the set value of the flow restriction setting unit 31 and the flow Q from the load restriction mechanism 16 and outputs the deviation when the deviation ΔQ exceeds a predetermined level.
A comparator 34 having a switch function C is connected to the output side, and is a control amplifier connected to the limiter for decreasing the set value of the speed regulator 13.

Thus, the load limiting mechanism 16 outputs the flow rate Q according to the output of the speed adjuster 13, but the output of the governing mechanical system 15 reaches the set value of the load limit setting device 21. Then
The flow rate Q limited by the overload limit set value is output.

The flow rate Q is the set value of the flow rate limiter 31.
When the deviation ΔQ exceeds a predetermined value, the limiter 32
Is output to the speed adjuster 13 via the control amplifier 34, and the speed set value set in the speed adjuster 13 is reduced according to the deviation ΔQ. The flow rate Q is limited by the decrease in the speed set value.

At the same time, the comparator 33 operates, and the switch setting C locks the flow rate increasing operation of the speed setting switch 11, so that the setting of the speed regulator 13 cannot be increased by the speed setting switch 11.

When the turbine generator 17 is operated in parallel with the power system, the speed detector 19 indicated by a dotted line becomes an open loop, and the operation amount of the speed setting switch 11 changes the generator output. Thus, the speed setting becomes the output setting.

[0010]

In recent years, in order to reduce equipment costs of a hydroelectric power plant, all waterways have been omitted, or a headrace waterway with a low tolerance has been used. The former requires suppression of surge tank surging, and the latter has a limitation due to a rise in pressure in the road, in addition to suppression of surging.

Basically, gradual flow control is performed. However, it is necessary to strictly control the excess of the limited flow rate due to erroneous operation of the speed setting switch.

By the way, the conventional flow rate adjusting method of the water flow generator shown in FIG. 4 has the following problem because the correction control is performed after the flow rate reaches the limit flow rate.

(1) The speed of the speed adjuster 13 is set by the speed setting switch 11. Therefore, when the disturbance is at the point A and the flow rate exceeds the limit flow rate, the flow rate limiting circuit 30 controls the speed regulator 13 to return it to within the limit value, and when the disturbance ends, the speed regulator 13 controls the limiter 32. Since there is no reverse control due to the characteristics and the position is maintained, resetting is necessary.

(2) In this method, the flow rate may reach the limit flow rate due to an erroneous operation.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and has as its object to eliminate the need to reset the speed setting device or the load limit setting device after the end of disturbance. An object of the present invention is to provide a method of limiting the output (flow rate) of a water turbine generator that does not exceed a flow rate limit value even if a speed setting device is erroneously operated.

[0016]

In order to achieve the above-mentioned object, a method for limiting the output of a turbine generator according to the present invention is characterized in that the flow rate of the turbine generator is controlled by a load limiting mechanism in accordance with a set value of a speed setting device. controlling, when the flow rate exceeds the setting value of the load limit setting unit which is set by the load limit setting switch cabana free water turbine generator limits the flow rate at this setting
In operation, the servo opening is calculated from the flow rate
-Guide vane servo opening is calculated using the head-flow curve.
From this opening, the load limit position is calculated, and the load
Control position of load limit setting device using limit position as set value
To limit the flow rate.

[0017] Alternatively , the load limiting mechanism may
The flow rate of the speed setting device set by the speed setting switch
The flow rate is controlled according to the set value, and the flow rate is
Load limiting operation of the turbine generator to limit the flow rate
At the guide vanes
The governor opening is calculated and the governor rigidity is restored according to the opening.
The speed setting device calculates the stiffness recovery amount as a set value.
Control the setting position of to limit the flow rate.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described with reference to the drawings.

The same components as those of the prior art shown in FIG. 4 are denoted by the same reference numerals, and the description thereof will not be repeated.

Embodiment 1 FIG. 1 shows an example of governor-free operation of a water turbine generator.

In FIG. 1, reference numeral 12 denotes a speed setting switch 1
1 is a speed setting device set by 1, and 20 is a load limit setting switch .
Switch, 21 is a load limit setting device, 22 is a flow rate limiting circuit, 23 is a flow rate limit setting device, 24 is a head drop detector, and 26 is a limiter using the opening-head-flow rate curve from the limit flow rate set value and head. An opening calculating section for outputting the guide vane servo opening at the time of flow, an opening / load limiting position calculating section 27 for calculating a load limiting position at a relative position from the opening, and a setting 29 of the load limiting setting device 21 This is a control amplifier that controls the position to be equal to the load limit position of the calculation unit 27.

The constant output setting is performed by setting the speed setting unit 12 by the speed setting switch 11. The load limit setting device 21 is at a position operated by the load limit setting switch 20. In addition, the restriction flow rate setting device 23
Flow rate is set.

Normally, a load limiting mechanism is set based on the speed setting.
The turbine generator 17 is operated at the flow rate Q output from the turbine 16.
You. During this operation, if the flow rate Q increases due to disturbance,
The water level fluctuates and the head decreases. Therefore, the opening-head
The opening degree calculation unit 26 that calculates the opening degree using the flow rate curve;
The output decreases, and the output of the opening / load limit
Because of the decrease, the setting of the load limit setting device 21 is set low,
The load limiting mechanism 16 controls the flow rate Q output from the
Limit the flow rate to the set value.

Since the load limit setting unit 21 is connected and controlled by the flow rate limiting circuit 22, when the disturbance ends, the set value automatically returns to the position set by the load limit switch before the occurrence of the disturbance .

During the control of the disturbance occurrence period, the speed setting unit 1
2 is not operated, so that the process returns to the normal output control together with the disturbance elimination. Therefore, there is no need to reset the speed .

In the governor-free operation, the generator output PA is set at the intersection A between the speed regulation rate and the system frequency depending on the position of the speed setting device 12, as shown in FIG.

Thus, even if the output setting switch (speed setting switch 11) is increased, the output does not exceed the generator output PB exceeding the intersection B determined by the load limit setting device 21.

Therefore, when the position of the load limit setting device 21 is at the flow rate limit value, the generator output, that is, the flow rate Q does not increase even if the speed setting switch 11 is further increased, so that the speed setting switch 11 is operated. Therefore, the flow rate limit value is not exceeded.

In the above embodiment, the limitation on the flow rate of the generator is described. In this case, the power can be limited by the same system.

Further, since the head (water level) is used for the flow rate restriction, it is possible to cope with a head with a drastic change in the water level of the dam.

Embodiment 2 FIG. 3 shows an example of load control operation of a water turbine generator.

In FIG. 3, reference numeral 22 denotes a flow rate limiting circuit.
3 is a flow control setter, 25 is a dam water level detector, 26 is the limit flow set value and dam water level (head) input, and the opening degree calculation for calculating the guide vane servo opening from the opening-head-flow rate curve. , A stiffness restoration calculation unit for calculating the stiffness restoration from the opening degree, and 29 a deviation between the stiffness restoration and the set value of the speed setting unit 12, and the set position of the speed setting unit 12 is set by the stiffness restoration. It is a control amplifier to control.

However, the normal output control is performed in the speed setting mode.
The speed setting device 12 is controlled by the switch 11. A load limit setting device 21 is set by a load limit setting switch 20. When the flow Q increases due to disturbance, the dam water level
(Head) decreases. The opening calculating section 26 is a guide vaneser.
1 is the opening-head-flow rate curve as in Fig. 1.
Then , the rigidity restoration component is calculated from the servo opening by the arithmetic unit 2
Obtained in 8, and controls the set position of the speed setter 12 by a control amplifier 29 so as setting command.

Referring now to FIG. 2, it is now assumed that the load limiter 29 is at the generator output PA position and the speed limiter 12 is at the dotted line position due to the flow rate limit.

In this state, even if the load limit setting switch 20 is operated in the increasing direction in order to increase the generator output, the output does not increase when it exceeds the PB point. As a result, the same effect as the embodiment of FIG. 1 is produced.

The load limiting mechanism shown in FIGS. 1 and 3 may be either electrical or mechanical. The system shown in FIGS. 1 and 3 can be constituted by either an analog system or a digital system.

[0037]

Since the present invention is configured as described above, the following effects can be obtained.

(1) When a disturbance occurs, the setting of the speed setting device or the load limit setting device, which is controlled back, automatically returns to the original setting when the disturbance ends, so there is no need to reset it.

(2) Since resetting is not required, there is no possibility that the flow rate reaches the limit flow rate due to an erroneous resetting operation.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing a system configuration according to an embodiment.

FIG. 2 is a diagram showing a relationship between a speed setting, a load limit setting, and a generator speed.

FIG. 3 is a block circuit diagram showing a system configuration according to another embodiment.

FIG. 4 is a block circuit diagram showing a system configuration according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Flow control circuit 11 ... Speed setting switch 12 ... Speed setting device 13 ... Speed regulator 14,24,34 ... Control amplifier 15 ... Governing machine system 16 ... Load limiting mechanism 17 ... Water turbine generator 18 ... Stiffness restoration system 19 ... speed detecting unit 20 ... load limit setting switch 21 ... load limit setting device 22, 30 ... flow rate limiting circuit 23, 31 ... limited flow rate setting device 24 ... head drop detector 25 ... dam water level detector 26 ... opening degree calculation unit 27 ... Opening / load control position calculation unit 28 ... Opening / rigidity restoration calculation unit 32 ... Limiter 33 ... Comparator

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 9/04

Claims (2)

(57) [Claims] A load limiting mechanism controls the flow rate of the turbine generator in accordance with a set value of a speed setting device. When the flow rate exceeds a set value of a load limit setting device set by a load limit setting switch, the set value is set. In the cabana-free operation of the turbine generator that limits the flow rate, the servo opening-head-flow curve
Calculate the guide vane servo opening using the line, and
And a load limit position is calculated from the calculated load limit position, and the set position of the load limit setting device is controlled using the load limit position as a set value. 2. A load limiting mechanism controls the flow rate of the turbine generator according to a set value of a speed setting device set by a speed setting switch, and the flow rate becomes equal to or more than a set value of the load limit setting device.
Then, in the load limiting operation of the turbine generator that limits the flow rate, the guide vane servo opening is calculated from the flow rate setting value and the head , the rigidity restoration of the governor according to this opening is calculated, and this rigidity restoration is calculated. A method for limiting the output of a water turbine generator, comprising controlling a set position of a speed setting device as a set value.