JP2858826B2 - Guide vane opening and closing device for hydroelectric power plant - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a guide blade opening / closing device for a hydroelectric power plant using an electric servomotor as a drive source, and in particular, operating guide vanes with a plurality of electric servomotors. The present invention relates to a guide vane opening / closing device for a hydroelectric power plant that is suitable to be used.

[Conventional technology]

As described in Japanese Utility Model Application Laid-Open No. 61-29983, a conventional device has been proposed for a guide blade opening / closing device using an electric servomotor, but using a plurality of electric servomotors and controlling them synchronously. It was not proposed to do so.

[Problems to be solved by the invention]

In the prior art, no consideration is given to synchronous control of a plurality of electric servomotors, and when a guide blade is operated by a plurality of electric servomotors, the electric servomotor is operated in a transient state when the guide blade is operated. Since the motors are asynchronous, the operating force of the guide vanes cannot be distributed to each electric servomotor as planned, and there is a problem that the electric servomotor causes an overload phenomenon. Therefore, in the prior art, it was impossible to operate the guide vanes with a plurality of electric servomotors.

A first object of the present invention is to provide a guide blade opening / closing device for a hydroelectric power plant that controls a plurality of electric servo motors synchronously and distributes the operation force of the guide blades to each electric servo motor.

A second object of the present invention is to provide a method for controlling a plurality of electric servomotors synchronously and operating guide vanes, even when the synchronous control does not operate normally, in operation of a hydraulic power distribution station. An object of the present invention is to provide a guide blade opening / closing device for safely controlling a blade.

[Means for solving the problem]

In order to achieve the first object, in the present invention, there are provided rotation speed detection means provided for each of the plurality of electric servomotors, and the control circuit receives a rotation speed signal from the rotation speed detection means and First closed loop means for determining a speed deviation between the average speed of the plurality of electric servomotors and the rotation speed of each electric servomotor and adding the speed deviation to the speed command;
And a second closed loop means for negatively feeding back the rotation speed signal from the rotation speed detection means to the speed command corrected by the closed loop means, wherein a plurality of electric servos are provided by the first closed loop means and the second closed loop means. The motor is controlled synchronously.

In order to achieve the second object, the present invention provides a guide blade opening / closing device for a hydroelectric power plant comprising a synchronous control circuit for synchronously controlling the outputs of a plurality of electric servomotors. A protection circuit is provided for closing the guide vanes or maintaining the current opening when the asynchronous state of the output between the motors becomes excessive.

[Action]

In the first invention of the present application, a speed command input to each electric servomotor is corrected by adding a deviation between the average speed and each motor speed, and the actual speed of the motor matches the speed command value. This allows each motor to be synchronously controlled while making each motor follow the speed command.

In the second invention of the present application, when synchronous control of a plurality of electric servomotors does not operate normally, a safe direction in operation of the hydroelectric power plant, that is, the guide blade is closed or the current opening is maintained. Since a command is issued to the control circuit of the electric servomotor, even if the operations of the plurality of electric servomotors become asynchronous, a serious accident at the hydroelectric power plant can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1 for a guide vane opening / closing device using two electric servomotors having the same specifications.

Two electric servomotors 4 and 5 are individually connected to a guide ring 3 connected to the guide blade 1 via a link mechanism 2. These operating state detection signals 6 and 7 of the electric servomotor are taken into the control circuit 10 of the electric servomotor and also taken into the synchronous control circuit 8 at the same time. Here, the operation state detection signals 6 and 7 are composed of armature currents of the electric servomotors 4 and 5 and rotation speed signals of the rotor.

The synchronous control circuit 8 obtains a deviation between the armature current and the rotation speed of the rotor of both the electric servomotors 4 and 5 from the operation state detection signals 6 and 7 taken in, and corrects the deviation to eliminate the deviation. The signal 9 is output to the control circuit 10.
The control circuit 10 outputs control signals 11 and 12 for the electric servomotors 4 and 5 in consideration of the copy signal 9.

As a result, the asynchronous elements of the electric servomotors 4 and 5 can be eliminated, so that the output torque and the operation speed of the electric servomotor can be controlled synchronously, and the electric servo by distributing the operation force of the guide blade 1 can be controlled. Problems such as an overload phenomenon of the motor can be prevented.

FIG. 2 shows an example of a recently considered control circuit, which is an example of a speed control loop of the electric servomotors 4 and 5 to which a speed command is input. When controlling multiple units,
A speed control loop is connected in parallel to the speed input signal 20 for the number of vehicles. The deviation between the speed input signal 20 and the speed feedback signal fed back via the rotor speed feedback gain 30 is amplified through the speed gain 21. The speed deviation signal and the current feedback signal fed back via the armature current feedback gain 29 at the addition point 23 are calculated. That is, the speed deviation is converted into a current deviation. The current deviation is supplied to the armature 26 of the electric servomotor 4 via the current gain 24,
And acts as an output torque or an acceleration torque of the electric servomotor 4 via the. Here, if the rotor rotates, a back electromotive voltage proportional to the rotation speed is generated in the armature, and is fed back to the current input section to the armature 26 via the back electromotive voltage gain 31.

Further, the output torque or acceleration torque of the electric servomotor 4 is combined with an external force, and the deviation is output from the power cylinder as the operation of the electric servomotor 4.
Since the other electric servomotor 5 has the same structure as the synchronous control circuit of the electric servomotor 4, it is attached, for example, as an armature 26 ', and the description is omitted.

In such a control circuit for an electric servomotor, the third
A synchronization control circuit including an adder 32 and a divider 33 shown in the figure is added. That is, FIG. 3 shows an example of a synchronous control circuit that has recently been considered. The armature current feedback signals of the electric servomotors 4 and 5 are added by the adder 32, and The sum of the armature currents is determined. The total armature current is proportional to the output torque of the electric servomotors 4 and 5 when viewed statically. In other words, it can be considered that it is the operation force of the guide blade 1. Therefore,
By dividing the sum of the armature currents by 1 / n (n: the number of electric servomotors) in the divider 33, the average value of the armature currents, that is, the torque to be output by the electric servomotors 4 and 5 per motor is obtained. be able to. Add the deviation between the average value of the armature current found in this way and the current armature current flowing
At 34, this deviation is added to the velocity deviation signal input via the velocity gain 21 and added at the matching point 22, whereby the armature current can be corrected to the average value. As a result, the plurality of electric servomotors 4 and 5 share the operating force of the guide blade 1 at a substantially equal or predetermined ratio, and can prevent an overload phenomenon in which only one of the electric servomotors bears. For this reason, the life of the electric servomotor can be extended,
Alternatively, since an electric servomotor having a small capacity can be used, the size of the guide blade opening / closing device can be reduced.

FIG. 4 shows an embodiment of the present invention, in which an adder 37,
A synchronous control circuit for compensating the rotational speed of the rotor composed of the divider 38 is added. That is, in the present invention, the rotational speeds of the rotors of the electric servomotors 4 and 5 are added by the adder 37 and further divided by the divider 38 to 1 / n (n: the number of electric servomotors). Servo motor 4,5
The average value of the rotation speeds of the rotors is obtained. Since the deviation between the average value and the rotation speed of the rotor can be considered as an asynchronous amount of the operation speed of the electric servomotor, it is necessary to correct the deviation amount of each of the electric servomotors 4 and 5 with respect to the average value of the rotation speed of the rotor. Thus, the operating speeds of all the electric servomotors can be synchronized. Accordingly, in the present invention, the deviation amount between the output of the divider 38, that is, the average value, and the speed feedback signal via the rotor speed feedback gain 30 is added to calculate at the joining point 39 and added to the speed input signal 20. This is achieved by adding and correcting at the matching point 36.

Further, as shown in FIG. 5, a comparator 40 for monitoring a deviation amount (an addition point 34 output) between the average value of the armature current of the electric servomotor and the armature current of each electric servomotor,
The deviation between the average rotation speed of the rotor of the electric servomotor and the rotation speed of the rotor of each electric servomotor (addition point
39 output), the control circuit 10 of the electric servomotor is suitable for the operation of each hydroelectric power plant when the current deviation or the rotation speed deviation exceeds a preset deviation. A state, that is, a control command for controlling the closing operation of the guide blade or maintaining the current opening degree is output from the comparator 40 or 41 to the control circuit 10 of the electric servomotor.
If the amount of out-of-sync is excessive due to this protection method,
Hydropower plants can be steered in a safe direction. It should be noted that a time element, the number of times of integration, and the like can be added to the output condition of the comparator 4 or 41.

Here, there is no problem even if the synchronous control circuit combines the correction of the armature current and the correction of the rotor rotation speed.

〔The invention's effect〕

According to the present invention, when operating the guide blades of a hydroelectric power plant with a plurality of electric servomotors, synchronous control of these electric servomotors is performed while causing each electric servomotor to follow a speed command. Since the overload phenomenon due to the asynchronousness of the electric servomotor can be prevented, it is possible to configure the guide blade control device using the electric servomotor, and there is an effect that the entire guide blade opening / closing device can be reduced in size.

Also, the asynchronous state of each electric servomotor is monitored, and when the asynchronous state between each electric servomotor becomes excessive,
By adopting a protection method that outputs an appropriate control command to the control circuit of the electric servomotor, even if the synchronous control circuit of the electric servomotor fails, the overload phenomenon can be prevented beforehand, and at the same time the hydraulic power plant There is an effect that the user can be guided in a safe direction commensurate with the operation.

[Brief description of the drawings]

FIG. 1 is a block diagram of a guide blade opening / closing device of a hydroelectric power plant according to an embodiment of the present invention, FIG. 2 is a block diagram of a recently considered electric servomotor control circuit, and FIG. FIG. 4 is a block diagram of an electric servomotor control circuit provided with a synchronous control circuit for armature current correction. FIG. 4 is a block diagram of an electric servomotor control circuit provided with a synchronous control circuit for rotor rotational speed correction according to one embodiment of the present invention. FIG. 5 is a block diagram of a protection circuit provided in the electric servomotor control circuit according to one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Guide blade, 2 ... Link mechanism, 3 ... Guide ring, 4 ... 1st electric servomotor, 5 ... 2nd electric servomotor, 6, 7 ... Operation state detection signal, 8 ... ... Synchronous control circuit, 9 ... Correction signal, 10 ... Electric servo motor control circuit, 11,12 ... Control signal, 20 ... Speed input signal, 2
1 ... speed gain, 22, 23, 25, 34, 35, 36, 39 ... addition point, 24 ... current gain, 26 ... armature, 27 ... torque gain, 28 ... rotor, 29 …… feedback gain of armature current, 30…
… Rotational speed feedback gain, 31 …… back electromotive voltage gain, 32,37 ……
Adders, 33, 37 ... Dividers, 40, 41 ... Comparators.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F03B 15/04 F03B 3/18

Claims (2)

(57) [Claims] 1. A guide blade for adjusting a flow rate flowing through a water turbine runner, a guide ring for rotating the guide blade, and a plurality of electric servomotors for driving the guide ring to adjust the opening of the guide blade. And a guide blade opening / closing device for a hydroelectric power plant comprising a control circuit for controlling the outputs of the plurality of electric servomotors, comprising: a rotation speed detecting means provided for each of the plurality of electric servomotors; The control circuit inputs a rotation speed signal from the rotation speed detection means, calculates a speed deviation between the average speed of the plurality of electric servomotors and the rotation speed of each electric servomotor, and adds the speed deviation to a speed command. And a second closed loop means for negatively feeding back a rotation speed signal from the rotation speed detection means to a speed command corrected by the first closed loop means, The closed loop means and said second closed loop means, guide vane closing device for hydroelectric power plants, characterized in that synchronously controlling the plurality of electric servo motor. 2. A guide blade for adjusting a flow rate flowing through a water turbine runner, a guide ring for rotating the guide blade, and a plurality of electric servomotors for driving the guide ring to adjust the opening of the guide blade. And a synchronous control circuit for synchronously controlling the outputs of the plurality of electric servomotors, the asynchronous state of the output between the plurality of electric servomotors is excessive in the guide blade opening and closing device of the hydroelectric power plant. In this case, a guide circuit for a hydroelectric power plant is provided with a protection circuit for closing the guide blade or maintaining the current opening.