JPH06257552A - Electric speed governor for causing discharge from deflector - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] The control loops for the needle and deflector of the Pelton turbine at the spillway omitted hydropower plant are not independent, and control at the time of re-parallelization into the system after the accident recovery is Prevent instability. [Structure] Nozzle opening command value is given by an opening setting device 7 for adjusting the water level in the upper water tank, and deflector opening command value is given by the output value of the speed controller before and immediately after system parallel insertion. Therefore, until the steady power generation, the opening control system of the nozzle and the deflector are made independent from each other to stabilize the control at the time of parallel entry, and during the steady power generation, the output upper limit value of the speed regulator is set by the deflector upper limit opening limiter. The deflector opening is maintained at the optimum position according to the nozzle opening as in the conventional case by limiting the upper limit value according to the above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow-in power plant in which a spillway is omitted (that is, all the inflow water from the upstream is normally guided to a turbine to generate electric power, and the deflector is used to stop the turbine or reduce its load. The electric jet speed control device for a Pelton turbine generator in a power plant of a method in which a jet jet is deflected from the Pelton turbine and discharged downstream). In the drawings below, the same reference numerals indicate the same or corresponding parts.

[0002]

2. Description of the Related Art As a prior art of this type, there is JP-A-61-200381, which is a prior application of the present applicant. Next, the technology of this prior application will be described.

FIG. 3 shows an outline of the main part of the structure of the Pelton turbine. A water conduit 31 for guiding water from a head tank (not shown) is provided with a plurality of branch pipes 32, 32a. Needle shafts 33a having needles 33 provided at the ends of the branch pipes 32, 32a pass through the curved pipes 34, 34a, respectively, and the nozzle pipes 35, 3
It is supported by a bearing (not shown) provided in 5a and reciprocated by a driving device (not shown). The needle 33 moves the nozzles 36, 3 by the reciprocating movement of the needle shaft 33a.
6a is inserted and withdrawn, the opening of the nozzle is adjusted, and the water flow from the head tank is ejected as a jet water flow at this opening. This jet water flow hits a large number of buckets 37a provided on the runner 37, causing the runner 37 to rotate in the direction of the arrow. The electric power can be taken out by driving the generator connected to the shaft 37b of the runner 37.

The deflector 38 is rotatably provided so as to cover the nozzle, and the position of the needle and the deflector is set to an optimum relationship (that is, by the correlation characteristic of the needle and the deflector via the deflector tracking controller 10). At the time of power generation, the deflector always applies all the jet flow to the water turbine, and when the jet flow needs to be deflected (relative to the water turbine), the deflector waits at a position where it can operate without dead time). The deflector covers the nozzle so as to change the direction of the jet water flow ejected from the nozzle when the system is shut off, thereby preventing an abnormal rotation speed increase of the runner and a sudden pressure increase of the penstock. In a Pelton turbine at a pouring power station, a head tank is equipped with a water level adjuster, the opening of a needle and a nozzle are adjusted according to the water level, and electric power corresponding to the jet water flow ejected from this opening is generated via a runner 37. It is taken out by the machine and a so-called water level adjustment operation (abbreviated as water conditioning operation) is performed. In this case, the frequency of the generator is the frequency of the parallel grid.

A frequency setting device, a controller, etc. for setting and controlling the rotation speed of the Pelton turbine are provided to set and control the rotation speed of the turbine during no-load operation when disconnected from the power grid. There is.

In the water conditioning operation of the Pelton turbine as described above, the deflector is suddenly closed when the system is disconnected from the power grid, and the direction of the jet water jet ejected from the nozzle is changed so as not to hit the runner bucket. The needle is closed while suppressing the increase in the number of rotations.

Next, the control circuit of the Pelton turbine of the prior application in the water conditioning operation will be described. FIG. 2 is a circuit diagram of a main part of a control circuit (that is, an electric speed governor) of the Pelton turbine. In the figure, the needles provided in the two groups of branch pipes are reciprocated by the servomotors 1 and 1a adjusted by the opening adjusters 2 and 2a, respectively, and are inserted into and withdrawn from the nozzle to adjust the needle opening. The opening degree is detected by the opening degree detectors 3 and 3a, respectively. The deflector is adjusted by an opening adjuster 5 and rotated by the servo motor 4 so as to cover the nozzle, and an opening detector 6 indicating the opening is provided.
The opening degree is detected by.

Here, the changeover switch 23 includes circuits 20 and 21.
And a circuit provided between the circuit 20 and the circuit 22 and interlocked with the increase in the rotational speed of the runner detected by the frequency detector 17. In the changeover switch 23, the switch contact 23a is open and both 23b and 23c are closed during normal water conditioning operation. When the number of revolutions of the runner detected by the frequency detector 17 increases, the switch contact 23a closes, 23
Both b and 23c are open.

Therefore, during the water conditioning operation, the water level adjusting opening setter 7 for controlling the water level, which is controlled by the water level of the head tank for water feeding to the Pelton turbine, is in the closed switch contact 23.
Opening detectors 3, 3 by adders 8, 8a via b, 23c
The detected opening degree from a is fed back, and the reciprocating motion of the needle is controlled by the servomotors 1 and 1a. In addition, the water level adjusting opening setting device 7 similarly has a switch contact 23.
b, the deflector tracking controller 10 and the adder 27 feed back the detected opening from the deflector opening detector 6 by the adder 9 to control the deflector opening by the servo motor 4.

On the other hand, a frequency setter 1 for setting and controlling the number of revolutions of the runner disconnected from the power grid during no-load operation.
1 passes through the adders 12 and 13 and the PID controller 14, one to the servomotors 1 and 1a via the switch contact 23c and the adders 8 and 8a, and the other to the servomotors through the deflector tracking controller 10 and the adders 27 and 9. It is connected to the motor 4. Then, in the adder 13, the detected opening degree from the opening degree detectors 3 and 3a is calculated by the adder 15, and this is fed back to the adder 13 via the rigidity restoration controller 16.
The detected frequency from the frequency detector 17 is fed back to the adder 12.

In the control circuit as described above, in the water conditioning operation of the Pelton turbine, the needle is driven by the servo motors 1, 1a by the water level adjusting opening setting device 7 for adjusting the water level of the head tank.
The opening of the needle is maintained so that the water level of the head tank is adjusted, and the water sent to the branch pipe is jetted from this opening as a jet water flow. The jet water stream hits the bucket of the runner, and the electric power corresponding to the amount of water sent is taken out from the generator.

On the other hand, the deflector is a deflector tracking controller 1.
The optimum position of the needle and the deflector is maintained by 0, and the deflector is rotated and positioned by the servo motor 4.

When the system cutoff occurs and the runner rotation speed increases, the frequency detector 17 detects an increase in rotation speed,
As described above, open the switch contacts 23b and 23c
By closing a, circuits 21 and 20 and 22 and 2
4 is disconnected and circuits 20 and 24 are connected. Therefore, the needle receives the signal from the water level adjusting opening setting device 7 and the opening adjusting devices 2 and 2a, and the servomotors 1 and 1 are operated.
a, the opening detectors 3 and 3a, and the rigid body restoration controller 16 adjust the opening of each needle, and the water flow from the head tank is discharged at this opening to maintain the water level in the head tank. It At the same time, the deflector is a frequency setter 11, a frequency detector 17, and a PID controller 1.
4, the opening regulator 5, the servo motor 4, and the opening detector 6 are used to cover the jet water flow ejected from the nozzle to change its direction to prevent the runner from abnormally increasing its rotational speed. Due to the action of the controller and the like, the deflector maintains the opening degree at which a part of the jet water flow is ejected to the runner, and holds the set rotational speed during no-load operation. In this case, the frequency dead zone controller 26 is inserted between the circuit 28 and the adder 27 as much as possible to reduce the swing of the deflector.

The parallel entry into the electric power grid is immediately performed by the held rotational speed during no-load operation, and after the parallel entry, the changeover switch 23 is switched to perform normal operation.

[0015]

As described above, the conventional electric speed governor for a Pelton turbine of a spillway omitted hydroelectric power plant does not separate the deflector control loop and the needle control loop, and The adjustment opening setting device 7 is also implemented by one, and in case of an accident such as a system interruption, the opening setting device 7
The object to be controlled is switched to the needle, and the object to be controlled in the speed control loop is switched to the deflector for control. However, such an electric speed governor has the following problems.

In this water turbine speed control mode before re-re-entry for re-entry into the system after the accident recovery, the deflector is P
The deflector tracking controller 10 is controlled by the output of the ID controller 14.
The opening is controlled via the deflector tracking controller 10.
Is selected as a characteristic that should correspond to the needle opening degree after parallel entry into the system, and therefore the gain is too high at the time of the low opening degree of the deflector before this re-parallel entry, and delicate water flow adjustment for the water turbine cannot be performed.

After re-paralleling into the system, the control target of the opening command value by the speed control loop is switched from the deflector only to the needle and the deflector, and parallel control is performed, but when there is no load or light load immediately after re-paralleling. The opening command value is determined as the output of the PID controller 14 (at the time of low opening), and then the opening command value is changed to the PID when the steady state is gradually increased (that is, the load is increased). This is the output value of the water level adjustment opening setting device 7 that regulates the upper limit of the output value of the controller 14.
Therefore, immediately after re-entry, until the opening command value output by the PID controller 14 follows the value of the water level adjustment opening setter 7,
The needle will be narrowed down and unnecessary movement will be performed. Further, this causes fluctuations in the water level in the upper water tank, which is not preferable. An object of the present invention is to provide an electric speed governor for deflector discharge, which solves these problems and improves the operation performance and control performance.

[0018]

In order to solve the above-mentioned problems, an electric speed governor according to claim 1 is a "nozzle (36, 36a) for ejecting a jet water flow to a runner (37 etc.) of a Pelton turbine generator. Nozzle opening control means (adders 8, 8a, opening adjusters 2, 2a, servos) that variably operate insertion and withdrawal of needles (33, etc.) so that the opening of the needles becomes equal to the nozzle opening command value. Motors 1, 1a, opening detectors 3, 3a, etc.),

Deflector opening control means for variably operating the attitude of the deflector (38, 38a, etc.) for deflecting the direction of the jet water flow from the direction of the runner so that the opening of the deflector becomes equal to the deflector opening command value. Adder 9, opening controller 5, servo motor 4, opening detector 6, etc.),

At least the speed deviation of the generator (obtained via the frequency setting unit 11, the frequency detector 17, the adder 12, etc.) is increased by PID calculation so that the speed deviation becomes zero, and the opening command value is obtained. PID adjusting means (PID
In the electric speed governor for deflector discharge provided with the controller 14 etc.,

The nozzle opening command value is given from a water level adjusting opening setting device (7 or the like) for adjusting the water level of the head tank for sending water to the nozzle,

At least before and immediately after parallel insertion of the generator into the system (via the upper limit opening calculator 106, etc.), the deflector opening command value is set as the opening command value output by the PID adjusting means. Do '

An electric speed governor according to a second aspect of the present invention is the above first aspect.
In the electric speed governor according to the paragraph [1], "means for limiting the upper limit value of the opening command value output by the PID adjusting means to a predetermined value according to the opening degree of the nozzle (high value selector 114, deflector upper limit opening degree) The limiter 113, etc.) ”.

[0024]

[Operation] Unlike the normal Pelton turbine, the deflector and needle of the Pelton turbine used in the spillway omitted hydropower station have the main function of adjusting the speed before the parallel entry, and the needle is the needle of the turbine. Focusing on the main function of adjusting the flow rate that controls the amount of water used according to the amount of water flowing into the upper tank regardless of the speed, the deflector opening is operated before and immediately after system insertion. The speed control loop for controlling the speed and the opening control loop for controlling the needle opening are separated, and the deflector opening command value is set to the speed controller (PID).
The output value of the controller) and the command value of the needle opening degree are given by the opening degree setting device 7 for adjusting the water level in the upper water tank, so that the control loops of the deflector and the needle do not interfere with each other in the state disconnected from the system. The control at the time of parallel entry was stabilized.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention and corresponds to FIG. In the figure, the opening of the needle is basically determined by a command from the conventional water level adjusting opening setting device 7. On the other hand, the opening of the deflector is commanded by the output of the PID controller 14 for speed control before and immediately after the parallel entry into the system, and during steady operation, the deflector upper limit opening limiter 113 and the upper limit opening calculator 106 are used. As in the conventional case, the optimum opening value corresponding to the opening of the needle is commanded. Therefore, the opening control loop of the needle and the opening control loop of the deflector are independent from each other before and immediately after the parallel insertion of the system.

In FIG. 1, the upper limit opening calculator 106 in the deflector control system includes a speed adjustment command (output of the PID controller 14), a command from the start / stop deflector opening limit setter 105, and a deflector upper limit. Opening limiter 1
The lowest value among the three values of the opening degree correlated with the needle given from 13 is output as the opening degree command value of the deflector.

The start / stop deflector opening limit setting device 105 is a setting device that is manually or automatically operated when the turbine is started or stopped. When the turbine is stopped, the setting device 1 is used.
By setting the output of 05 to 0% (opening), the deflector opening can be set to 0 in preference to the outputs of the PID controller 14 and the deflector upper limit opening limiter 113. On the other hand, when the water turbine is started, the output of the setting device 105 is promptly set to 100% so that it is not related to the actual opening command, and the opening of the deflector follows the output of the PID controller 14.

The adder 13, the stiffness restoration calculator 16, the divider 107, the load setter 111, and the adder 120 are used to give the electric speed governor a well-known stiffness restoration function (speed drooping characteristic). However, it is not directly related to the present invention.

Next, in the needle control system, the high value selector 114 determines whether the opening detection value 1 of the first group needle opening detector 3 or the second group needle opening detector 3a is the larger one.
14a is selected and given to the deflector upper limit opening limiter 113.

The deflector upper limit opening limiter 113 calculates the optimum deflector opening corresponding to the input needle opening detection value 114a and gives the upper limit opening calculator 106 as the upper limit value 113a. Determines the upper limit of the output of. Therefore, during steady power generation, the opening of the deflector is controlled to reach this upper limit value.

In this way, the deflector calculates the deviation obtained from the frequency setter 11, the frequency detector 17, and the stiffness restoration calculator 16 by the PID controller 14, and determines the optimum opening through the upper limit opening calculator 106. That is, before and immediately after the system parallel insertion, the deflector upper limit opening limiter 11 is set to the opening as the output value of the PID controller 14 regardless of the needle control system, and only in the steady state after the parallel insertion.
The output value 113a of 3 is controlled, that is, the optimum opening degree corresponding to the needle opening degree.

On the other hand, since the needle is controlled to an opening determined only by the needle water level adjusting opening setting device 7 which is adjusted according to the amount of inflow into the upper water tank (or according to the water level in the upper water tank), Unlike the electric speed governor of, it is not affected by the frequency signal.

[0033]

According to the present invention, the opening control loop for controlling the nozzle opening and the speed control loop for controlling the speed through the control of the deflector opening are mutually provided before and immediately after the system parallel insertion. Since they are independent of each other, it is possible to stabilize the control of each of the nozzle and the deflector at the time of system parallel insertion, and to prevent the water level fluctuation of the upper water tank due to unnecessary narrowing of the needle as in the conventional case.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a configuration as an embodiment of the present invention.

FIG. 2 is a conventional block circuit diagram corresponding to FIG.

FIG. 3 is a partial sectional view of a main part of the Pelton turbine structure.

[Explanation of symbols]

 1 Needle Servo Motor 1a Needle Servo Motor 2 Opening Controller 2a Opening Controller 3 Opening Detector 3a Opening Detector 4 Deflector Servo Motor 5 Deflector Opening Controller 6 Deflector Opening Detector 7 Water level adjusting opening setting device 8 Adder 8a Adder 9 Adder 11 Frequency setting device 12 Adder 14 PID controller 17 Frequency detector 32 Branch pipe 32a Branch pipe 33a Needle 36 Nozzle 36a Nozzle 37 Runner 38 Deflector 38a Deflector 106 Upper limit Opening calculator 113 Deflector upper limit opening limiter 114 High price selector

Claims (2)

[Claims] 1. A nozzle opening control means for variably operating insertion and withdrawal of a needle so that an opening of a nozzle for ejecting a jet water flow to a runner of a Pelton turbine generator becomes equal to a nozzle opening command value. Deflector opening control means for variably operating the attitude of the deflector so that the opening of the deflector that deviates the direction of the deflector from the direction of the runner becomes equal to the deflector opening command value, at least the speed deviation of the generator is set to zero. PID for increasing the deviation by PID calculation and outputting it as an opening command value
In an electric speed control device for deflector discharge provided with an adjusting means, the nozzle opening command value is given from a water level adjusting opening setting device for adjusting the water level of a head tank for supplying water to the nozzle, and at least the system to the system An electric speed governor for deflector discharge, wherein the deflector opening command value is set as the opening command value output by the PID adjusting means before and immediately after the parallel insertion of the generator. 2. The electric speed governor according to claim 1, further comprising means for limiting an upper limit value of the opening command value output by the PID adjusting means to a predetermined value according to the opening degree of the nozzle. An electric speed governor for deflector discharge, characterized in that