JPH08182393A - Method and apparatus for speed control of generator - Google Patents

Abstract

PURPOSE: To prevent a stoppage in operation of a generator even when a speed detector for a speed controller is out of order, by setting two kinds of speed signals with different detecting methods, and using these signals to compensate with each other in abnormal operation. CONSTITUTION: A speed governor controller 1 includes a speed control means 2 for receiving a speed signal and controlling speed, a main signal abnormality detection means 5 for generating a main abnormality detection signal (b) when the speed signal is out of order, and an auxiliary speed detection means 6 for detecting an auxiliary speed signal (c) in a different method from a main speed detection means 4. When the auxiliary speed signal (c) is out of order, a signal abnormality detection means 7 generates an alarm as an abnormality detection signal (d). A speed signal comparing means 8 compares the main speed signal (a) and the auxiliary speed signal (b) and generates a switch signal (e) when a deviation in speed signals is over a given deviation level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control method for a generator in a hydroelectric power plant, and an apparatus for speed control using the method.

[0002]

2. Description of the Related Art Conventionally, in controlling the speed of a generator in a hydroelectric power plant, a speed detector directly connected to the generator detects a speed signal from the rotation speed of the generator and controls the speed signal. The rotation speed of the generator is adjusted within a specified range by inputting it to the means, and at the same time, it is also input to the signal abnormality detector so that the occurrence of abnormality of the generator can be detected.

In the speed governor control device of the generator by such a method, when the speed detector detects that the generator has been started by the water turbine at the time of power generation and the rotation speed has reached a specified value, the speed governor is controlled. The control means operates to adjust the rotation speed of the generator so that it falls within the range of the specified value. When the signal abnormality detector detects an abnormality of the generator, the generator is stopped. Since the generator in operation is connected in parallel to the power transmission system via the parallel breaker, such an emergency stop of the power generator causes power fluctuation in the power transmission system.

In the conventional apparatus using such a speed control method, a permanent magnet generator or an electromagnetic pickup is often used as a speed detector of the generator.

[0005]

In the conventional speed control device having the above-described structure, even if the generator is not abnormal, the speed detector has a trouble such as a failure or a circuit disconnection or a short circuit. In this case, since there is no speed signal to be input to the speed control unit, speed control cannot be performed and it becomes difficult to continue normal operation. Therefore, the signal abnormality detector detects a defect in the speed signal, and even in such a case, the generator is stopped and necessary measures such as repair are taken.

By the way, when the generator that has entered the operating state is to be emergency stopped for some reason, it must be stopped rapidly as a result. Therefore, the above-mentioned unfavorable situation such as power fluctuation occurs. In addition to causing this, when adjacent generators share a hydraulic iron pipe for turbine input, fluctuations in water pressure may induce load fluctuations in adjacent machines. In this way, the emergency stop of the generator that has entered the operating state is to be avoided as much as possible except when it is unavoidable such as an abnormality of the generator main body.

On the other hand, if not only the failure occurs on the speed detector side but also the signal abnormality detector does not operate, the generator is not stopped, but this is also an undesirable situation. This is because the speed control means tries to increase the speed, but since it is parallel to the system, the speed does not increase, so that the generator load increases and the overload operation continues.

The present invention has been made in order to solve the problems in the conventional speed control method and apparatus as described above, and a speed detector for speed control and a signal abnormality detection are performed while the generator is in operation. A generator speed control method that enables stable current status operation without the need to stop the generator or overload operation even if a failure of the equipment or a failure such as a circuit disconnection or short circuit occurs And to provide a device.

[0009]

The speed control method of the present invention detects the speed signal of the generator and inputs the speed signal to the speed control means for speed control to control the speed signal of the rotation of the generator (mainly). , A speed signal (sub) obtained by a detection method different from the speed signal (main), and a speed signal deviation between the speed signal (main) and the speed signal (sub) are monitored, When no abnormality is detected in both the main) and the speed signal (sub), due to preset conditions,
One of the speed signal (main) and the speed signal (sub) is selected and input to the speed control unit, and the speed signal (main), the speed signal (sub), and the speed signal deviation are selected. When an abnormality is detected in at least one of the above, an alarm is issued, and a speed signal for which no abnormality is detected is selected and input to the speed control means.

The speed control device of the present invention is a speed control means for inputting a speed signal to perform speed control, and a speed for detecting a speed signal of rotation of a generator and outputting a speed signal (main). Detection means (main) and signal abnormality detection means (main) that outputs an abnormality detection signal (main) when an abnormality occurs in the speed signal (main), and detection that is different from the speed detection means (main) When a speed detection means (sub) for detecting the speed signal (sub) of the generator by the method and an abnormality occurs in the speed signal (sub),
A signal abnormality detection unit (sub) that outputs an abnormality detection signal (sub) and issues an alarm is compared with the speed signal (main) and the speed signal (sub), and the speed signal deviations thereof are a predetermined deviation specified value. If the speed signal comparison means for outputting a switching signal when the speed exceeds, and the speed signal (main) and the speed signal (sub) are input, and the abnormality detection signal (main) is not input, the speed signal (main) ) Is selected and output to the speed control unit, when the abnormality detection signal (main) is input and the abnormality detection signal (sub) is not input, or when the switching signal is input and the abnormality detection signal (sub) is input. When is not input, a speed signal switching means for issuing an alarm and switching the speed signal output to the speed control means to a speed signal (sub) is provided.

In the speed control method and apparatus of the present invention, the speed signal (main) may be any speed signal detected by a method normally used in the conventional speed control method and apparatus. Similarly, the speed signal (sub) may be any speed signal obtained by a detection method different from that of the speed signal (main). For example, an instrument transformer. A speed signal obtained from the frequency of the secondary circuit can be preferably used. The above configuration using the frequency detector as the speed signal detecting means (sub-device) can be easily applied to a plant which is currently operating with one system of speed signals.

As the device of the present invention, the speed signal (main) is obtained by a frequency detector and the speed signal (sub) is obtained by another method, or the timing or number of times of alarm generation is changed. Various modifications can be made without departing from the spirit of the method of the present invention.

For example, as the speed control device of the present invention,
In addition to the device having the above configuration, the speed signal selected when no abnormality is detected in both the speed signal (main) and the speed signal (sub) is set to be the high-value-side speed signal extracted by the high-value priority circuit. It may be a preset device. In that case, even if the rotation speed is unstable and immediately after the start of the operation of the generator, the device of the present invention enables good speed control.

[0014]

In the speed control method of the present invention, speed signals of two systems having different detection methods are adopted as speed signals of the speed control device, and in the event of an abnormality, speed control can be performed by complementing each other. ing. The speed control device of the present invention is configured so that the speed signals of these two systems can be effectively switched in accordance with the cause of the abnormality that has occurred and the necessary countermeasures.

Therefore, according to the method / apparatus of the present invention, it is necessary to prevent an emergency stop of the generator due to a failure of peripheral equipment such as a speed detector or a signal abnormality detector, without the need for these failures. Since measures can be taken, stable speed control of the generator can be performed. Therefore, the stable operating state of the generator is easily maintained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus according to an embodiment of the present invention for performing speed control by applying the method of the present invention will be described below with reference to the drawings. In each drawing, the same parts are designated by the same reference numerals, and duplicate description will be omitted. First Embodiment FIG. 1 is a diagram showing a configuration of a speed control device 1 which is an embodiment of the present invention. The speed control device 2 receives speed signals and controls speed control. , Speed detecting means (main) for detecting the speed of rotation of the generator 3 and outputting a speed signal (main) a
4 and signal abnormality detection means (main) that outputs an abnormality detection signal (main) b when an abnormality occurs in the speed signal (main) a
5, the speed detection means (sub) c for detecting the speed signal (sub) c of the generator 3 by a detection method different from that of the speed detection means (main) 4, and the speed signal (sub) c is abnormal. When they occur, the signal abnormality detection means (sub) 7 which outputs an abnormality detection signal (sub) d and issues an alarm is compared with the speed signal (main) a and the speed signal (sub) b, and their speeds are compared. The speed signal comparison means 8 which outputs a switching signal e when the signal deviation exceeds a predetermined deviation prescribed value, and the speed signal (main) a and the speed signal (sub) c are input, and the abnormality detection signal ( B)
Is not input, the speed signal (main) a is selected and output to the speed control means 2, and the abnormality detection signal (main) b is selected.
Is input and the abnormality detection signal (sub) d is not input, or when the switching signal e is input and the abnormality detection signal (sub) d is not input, an alarm is issued and output to the speed control unit 2. And a speed signal switching means 9 for switching the speed signal to the speed signal (sub) c.

Next, the operation of the speed control device 1 having the above structure when the method of the present invention is applied will be described. In the present embodiment, the generator 3 includes a power transmission system 11 via a parallel circuit breaker 10.
Are connected in parallel. The speed detecting means (main) 4 may be any speed detecting means, such as a permanent magnet generator or an electromagnetic pickup, as long as it is generally used as a speed detecting means for a generator. The speed detecting means (main) 4 detects the rotation speed of the generator 3, and the output speed signal a is the signal abnormality detector 5 and
It is input to the comparator 8 and the signal switch 9. Speed signal a
Exceeds a certain bandwidth with respect to the rated speed, or when an abnormality such as no signal is detected, the signal abnormality detector 5 operates and outputs the abnormality detection signal b. The output abnormality detection signal b is input to the signal switch 9.

In this embodiment, the speed detecting means (sub) 6
Is used as a frequency detector. This frequency detector is connected to the secondary voltage side of an instrument transformer (PT) that steps down the generator voltage to a low voltage, detects the frequency and outputs it as a speed signal c of the generator.

The speed signal c output from the speed detecting means (sub) (frequency detector) 6 is input to the signal abnormality detecting means 7, the speed signal comparing means 8 and the speed signal switching means 9. The signal abnormality detection means 7 detects an abnormality such as when the frequency detected as the speed signal c exceeds a certain bandwidth with respect to the rated frequency after a certain time has elapsed since the voltage of the generator is established, or when the frequency is not detected. When it occurs, it operates and outputs the abnormality detection signal d. When the abnormality detection signal d is output, the alarm 13 is generated and the abnormality detection signal d is input to the signal switch 9.

The speed signal comparing means 8 receives the speed signal c from the speed detecting means (sub) (frequency detector) 6 and the speed signal a from the speed detecting means (main) 4 and establishes the voltage of the generator. Then, both signals are compared after a lapse of a certain time, and when the speed deviation exceeds the deviation prescribed value, the switching signal e is output and input to the signal switching means 9.

The signal switching means 9 is a logic circuit 1 shown below.
A combination of 4, 15, 16, 17, 18, and 19, and a relay 21 and a contact 2 which operate by them.
2, 23, and 24.

In the signal switching means 9, the abnormality detection signal d
Is not input, that is, the abnormality detection signal d is “0”
At this time, the NOT circuit 14 outputs the output “1” to the AND circuit 1
5 and the AND circuit 16.

The AND circuit 15 receives "1" from the NOT circuit 14, that is, the abnormality detection signal d is not input, and further receives the abnormality detection signal b, that is, the abnormality detection signal b is "1". When it is "1", it operates so as to output the output "1". The output “1” from the AND circuit 15 is sent to the OR circuit 17.

The AND circuit 16 outputs the output "1" when "1" is input from the NOT circuit 14, that is, when the abnormality detection signal d is not input and when the switching signal e is input. To work. The output “1” from the AND circuit 16 is sent to the OR circuit 17.

The OR circuit 17 is an AND circuit 15 or A
When “1” is input from either the ND circuit 16 or the AND circuit 18, the output “1” is output to the relay 21 and the A
It operates so as to send to the ND circuit 18. When the output “1” is input to the relay 21, the speed signal a sent from the speed detector (main) 4 to the speed control means 2 is the contact 2
The contact 2 is separated by 2 and the speed signal c from the speed detector (sub) 6 is input to the speed control means 2.
An alarm 25 is issued by connecting the contact point 3 and the contact point 24.

The AND circuit 18 operates to output the output "1" when the output of the NOT circuit 19 is "1" and the output of the OR circuit 17 is "1". The NOT circuit 19 sends the output “1” to the AND circuit 18 when the reset push button 20 is “OFF”, and outputs the output “0” when the reset push button 20 is “ON”.
To send to. That is, the AND circuit 18 and the NOT circuit 19 together with the reset push button 20 are responsible for the reset mechanism of the present apparatus. When the reset push button 20 is "on", only when an abnormality detection signal or a switching signal is input. In addition, when the relay 21 operates so as to send the speed signal b to the speed control unit 2 and neither the abnormality detection signal nor the switching signal is input,
It operates so that the speed signal a is sent to the speed control means 2. When the reset push button 20 is turned off, the relay 21 operates so that the speed signal b is sent to the speed control unit 2 regardless of whether the abnormality detection signal or the switching signal is sent. According to the present embodiment having the above-described configuration and operation, the state in which the speed signal a is sent from the speed detecting means (main) 4 to the speed control means 2 is set as the initial state, and some abnormality occurs in the speed signal a. If
The occurrence of the abnormality is detected by the signal abnormality detecting means (main) 5 or the speed signal comparing means 8 monitoring the speed deviation. Therefore, if the signal abnormality detection means (sub) 7 does not operate at the time of occurrence of the abnormality, the speed signal c of the speed detection means (sub) 6 is normal and the generator is also normal, so the relay 21 Is operated to switch the speed signal to the speed signal c of the speed detecting means (sub). As a result, the speed control unit 2 can continuously obtain a normal speed signal, so that the current maintaining operation can be stably performed without the need to stop the generator 3 in an emergency. Also, when switching to speed signal c, alarm 2
Since 5 is also generated, it is possible to immediately take necessary measures for occurrence of the above abnormality.

Further, in the apparatus of this embodiment, only the alarm is issued when the signal abnormality detecting means (sub) 7 operates, and the NOT circuit 14, the AND circuit 15 and the AND circuit 1 are provided.
In combination with 6, the switching of the speed signal from the speed detecting means (main) side to the speed detecting means (sub) side is locked. This locking mechanism prevents unnecessary switching of the speed signal. Second Embodiment FIG. 2 is a diagram showing a configuration of an embodiment of a speed control device using a high value priority circuit 30 for signal switching in the method of the present invention. The apparatus includes speed control means 2 for inputting a speed signal to perform speed control, and speed detection means (main) 4 for detecting a speed signal of rotation of a generator 3 and outputting a speed signal (main) a.
And an abnormality detection means (main) 5 for outputting an abnormality detection signal (main) b when an abnormality occurs in the speed signal (main) a.
And the speed detection means (sub) c for detecting the speed signal (sub) c of the generator 3 by a detection method different from that of the speed detection means (main) 4 and the speed signal (sub) c is abnormal. At this time, the signal abnormality detection means (sub) 7 for outputting the abnormality detection signal (sub) d is compared with the speed signal (main) a and the speed signal (sub) c, and the speed signal deviations thereof are predetermined. When the deviation specified value is exceeded, the speed signal comparison means 8 for issuing an alarm, the speed signal (main) a and the speed signal (sub) c are input, and the abnormality detection signal (main) b or the abnormality is input. When neither detection signal (sub) d is input,
When the high-value side speed signal is selected by the high-value priority circuit 30 and output to the speed control unit 2, and at least one of the abnormality detection signal (main) b and the abnormality detection signal (sub) d is input. , And a speed signal switching means 9 for switching the speed signal output to the speed control means 2 to a direction in which no abnormality is detected while issuing an alarm.

Next, the operation of the speed control device having the above structure to which the method of the present invention is applied will be described. In the present embodiment as well, as in the first embodiment, the speed detection means (main) 4 detects the rotation speed of the generator (not shown) connected in parallel to the power transmission system via the parallel breaker. ing.

In the second embodiment, the signal switching means 9 comprises the high-value priority circuit 30, the relays 31, 32, the contacts 33, 34, 3.
5, and 36. Signal switching means 9
In, the high value priority circuit 30 inputs the speed signals a and b, selects the speed signal on the high value side from these speed signals, and outputs it to the speed control unit 2.

In the signal switching means 9, the abnormality detection signal b
Is input, the relay 31 operates to disconnect the speed signal a at the contact 33 and input only the speed signal c to the high-value priority circuit 30, and also operates the contact 34 to generate the alarm 37. Similarly, when the abnormality detection signal d is input, the relay 32 operates so that the speed signal c is disconnected at the contact 35 and only the speed signal a is input to the high value priority circuit 30, and the contact 36 is operated. Alarm 38 is generated.

Further, the speed signal comparing means 10 monitors the speed deviation of the speed signals a and b, and when the speed deviation deviates from the deviation specified value, an alarm 39 is issued. If the speed deviation is within the specified deviation value, the high speed side of the speed signal is always selected by the high value priority circuit 30 even if the speed detector gradually deteriorates.
Is input to Therefore, the speed control unit 2 can stably operate the generator in the current state without being affected by such deterioration of the speed detector. For comparison with the present invention, FIG. 3 shows an example of the configuration of a speed control device according to a conventional control method.

[0032]

As described above, by using the speed control method and the apparatus thereof according to the present invention, problems such as failure of the speed detector or disconnection or short circuit of the circuit may occur during operation of the generator of the hydroelectric power plant. Even if it occurs, it is configured so that the generator will not be suddenly stopped for repair each time and the power transmission system will not be shaken.Also, if an abnormality occurs, it is configured to appropriately notify by an alarm. Can be taken. In addition, since it is possible to eliminate the possibility of inducing load fluctuations of adjacent generators and continuing overload operation, it becomes easy to stably operate the generators in the current state.

The present invention can be easily applied to a plant that is currently operating with one system of speed signal by incorporating the frequency of the secondary circuit of the transformer for instrument (PT) as the speed signal (sub). It is possible. Further, the device of the present invention can be configured so that the speed control can be performed from the time when the voltage is unstable immediately after the start of operation of the generator.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a speed control device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a speed control device according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a speed control device in a conventional control method.

[Explanation of symbols]

 1 .... Speed control device 2 .... Speed control means 3 ... Generator 4 ... Speed detector (main) 5 ... Signal abnormality detection means (main) 6 ... Speed detector (Sub) (frequency detector) 7 ... Signal abnormality detection means (sub) 8 ... Speed signal comparison means 9 ... Signal switching means 10 ... Parallel circuit breaker 11 ... Transmission system 12 ... …… Instrument transformer 13, 25 ………… Alarm 14, 19 ………… NOT circuit 15, 16, 18 ………… AND circuit 17 ………… OR circuit 20 ………… Reset push button 21 ………… Relay 22 , 23, 24 ... Contact 30 ... High-priority circuit 31, 32 ... Relay 33, 34, 35, 36 ... Contact 37, 38, 39 ... Alarm a ... Speed signal (main) ) B ……… Abnormality detection signal (main) c ……… Velocity signal (sub) d ………… Abnormality detection signal (sub)

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G05D 13/62 F

Claims (6)

[Claims] 1. When detecting a speed signal of a generator and inputting the speed signal to a speed control unit for speed control, a speed signal (main) of rotation of the generator, and a detection method different from this speed signal (main). By monitoring the speed signal (sub) obtained by the above, and the speed signal deviation between the speed signal (main) and the speed signal (sub), both of the speed signal (main) and the speed signal (sub) are abnormal. Is not detected, one of the speed signal (main) or the speed signal (sub) is selected and input to the speed control means according to a preset condition, and the speed signal (main) and the speed signal (main) When an abnormality is detected in at least one of the speed signal (auxiliary) and the speed signal deviation, an alarm is issued, and the speed signal in which no abnormality is detected is selected and input to the speed control means. Of the generator characterized by Speed control method. 2. A speed control device for detecting a speed signal of a generator and performing speed control, wherein speed control means for inputting the speed signal and performing speed control, and a speed signal for rotation of the power generator are provided. A speed detection unit (main) for detecting and outputting a speed signal (main); a signal abnormality detection unit (main) for outputting an abnormality detection signal (main) when an abnormality occurs in the speed signal (main); A speed detection means (sub) for detecting the speed signal (sub) of the generator by a detection method different from the speed detection means (main), and an abnormality detection signal (sub) when an abnormality occurs in the speed signal (sub) ) Is output and an alarm is issued to detect a signal abnormality (sub)
And comparing the speed signal (main) with the speed signal (sub),
The speed signal comparing means for outputting a switching signal when the speed signal deviations exceed a predetermined deviation specified value, and the speed signal (main) and the speed signal (sub) are inputted, and the abnormality detection signal (main) ) Is not input, the speed signal (main) is selected and output to the speed control unit, and when the abnormality detection signal (main) is input and the abnormality detection signal (sub) is not input, or the switching signal Is input and the abnormality detection signal (sub) is not input, an alarm is issued and speed signal switching means for switching the speed signal output to the speed control means to the speed signal (sub) is provided. A characteristic generator speed control device. 3. A speed control device for detecting a speed signal of a generator and performing speed control, wherein speed control means for inputting the speed signal and performing speed control, and a speed signal for rotation of the power generator are provided. Speed detection means (main) for detecting and outputting a speed signal (main); and signal abnormality detection means (main) for outputting an abnormality detection signal (main) when an abnormality occurs in the speed signal (main), An abnormality has occurred in the speed detection means (sub) for detecting the speed signal of the generator by a detection method different from that of the speed detection means (main) and outputting the speed signal (sub) At this time, the signal abnormality detection means (sub) for outputting the abnormality detection signal (sub) is compared with the speed signal (main) and the speed signal (sub),
When the speed signal deviation exceeds a predetermined deviation specified value, a speed signal comparison means for issuing an alarm, the speed signal (main) and the speed signal (sub) are input, and the abnormality detection signal (main) Alternatively, when neither the abnormality detection signal (sub) is input, a high-value priority circuit selects a high-speed speed signal and outputs it to the speed control means, and the abnormality detection signal (main) or the abnormality detection signal (sub) When at least one of (1) is input, a warning signal is issued, and a speed signal switching means for switching the speed signal output to the speed control means to a speed signal for which no abnormality is detected is provided. Generator speed control device. 4. The speed signal (secondary) is a voltage transformer 2 for an instrument.
The method for controlling speed of a generator according to claim 1, wherein the method is detected by a frequency detector of the next voltage. 5. The speed signal selected when no abnormality is detected in both the speed signal (main) and the speed signal (sub) is a high value side speed signal extracted by a high value priority circuit. The speed control method for a generator according to claim 1. 6. The method according to claim 1, wherein either one of the speed detecting means (main) or the speed detecting means (sub) is a frequency detector for a secondary voltage of a voltage transformer. 2. A speed control device for a generator according to 2 or 3.