JPH02285948A - Generating system protector - Google Patents

Abstract

PURPOSE:To detect shearing of shear pin reliably reliably by detecting shearing of the shear pin through utilization of differential rotation between a synchronous generator and a prime mover then producing an alarm through an alarm means. CONSTITUTION:Pickups 20, 21 for detecting the rotation are mounted on the shafts of a prime mover 17 and a synchronous generator 18. A differential amplifier 26 produces the difference between the detected rotations. When the output from the differential amplifier 26 reaches to a predetermined level, i.e., when a shear pin 19c is sheared to separate the coupling section 19 between the prime mover 17 and the synchronous generator 18 thus producing differential pulse between the pickups 20, 21 higher than a predetermined level, a transistor 8 is conducted to operate an auxiliary relay 27 thus providing an output to an alarm unit not shown. By such arrangement, shearing of shear pin directly coupling the prime mover and the synchronous generator can be detected easily and reliably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rotation speed detection device provided for system protection in a power generation system in which a synchronous generator is driven by a prime mover.

[Conventional technology] In a power generation system in which a synchronous generator is driven by a prime mover,
As a conventionally used protection device, there is one shown in FIG. In this Figure 3, 1 is the prime mover (P/
M), 2 is a synchronous generator (6 or less, simply referred to as a generator) that is directly driven by this prime mover 1 via a coupling 3, and 4 is a transformer (PT) that detects the voltage generated by the generator 2. ), 4a is a transformer (PT) that detects the voltage of the system bus 7, which will be described later, 5 is a synchronous parallel circuit breaker, 6 is a current transformer (CT) for detecting the load current of the generator 2, and 7 is a transformer for detecting the generator load. A system bus bar for transmitting power, 8 is a power receiving circuit breaker from the electric power company, 9 is a load equipment, 10 is a current from the generator 2 or the system bus Al based on the current detection signal from the current transformer 6
An overcurrent relay that operates when the current from t17 to generator 2 becomes excessive, and 11 is an overcurrent relay that operates when power is flowing from generator 2 to system bus 7. It is inactive during normal times when power is flowing from generator 2 to system bus 7. A reverse power detection relay 12 operates when power flows in, and 12 is an overvoltage installed for the purpose of protecting the load equipment 9 and the generator 2 from overvoltage when the voltage of the generator 2 and the system bus 7 becomes excessive. Relay, 13 is generator 2
14 is an automatic voltage regulator that adjusts the voltage of the generator 2; and 15 is a synchronizer that detects synchronization between the generator 2 and the system bus 7. The detection device 16 is a governor device (GV) that adjusts the rotation speed of the prime mover 1.

Next, the operation will be explained. The prime mover 1 generates a generator 2
After adjusting the voltage of the generator 2 to almost the rated rotational speed by driving the generator 2, the voltage is adjusted to be almost the same as the voltage of the system mother 17 using the automatic voltage regulator 14.

By adjusting the governor group W116 attached to the prime mover 1, the frequency of the generator 2 is matched to the frequency of the system bus 7, and the synchronization detection device 15 closes the synchronous parallel circuit breaker 5.

After completing the synchronous paralleling of the generator 2 to the system bus 7, the governor device 16 is adjusted and the load of the generator 2 is set to the target value, so that the generator 2 can continue to output to the system bus 7. become.

During the above process, the generator 2 continues to output, and for some reason an excess torque exceeding the specified value is applied between the generator 2 and the prime mover 1. 1 The coupling that directly connects the generator 2 and the prime mover 1 If the shear pin 3 (not shown) is sheared, the prime mover 1 settles to a certain rotational speed after a transient speed change.

In addition, since the generator 2 is electrically connected to the system bus 7, the rotation speed does not change (that is, the rotation speed is determined by the frequency of the system bus 7 and the number of poles of the generator 2 itself), The output load of the generator 2 is lost because there is no shaft input from the prime mover l. Furthermore, 1 power generation is 8!2.

It is in a state of no-load operation as a synchronous motor.

At this time, power equivalent to the no-load loss of the synchronous motor will flow from the system bus 7 to the synchronous generator 2, but the reverse power detection relay 11 installed as a protection device operates and the flow of reverse power is prevented. Prevented.

[Problems to be Solved by the Invention] However, in the conventional power generation system protection device described above, since the reverse power detection relay 11 is selected based on the difference in reverse power withstand capacity depending on the type of prime mover 1, the synchronous generator 2
When operated as a synchronous motor, the no-load input power may be lower than the minimum detection power of the reverse power detection relay 11, making detection impossible. The first purpose is to prevent the yX motor 1 from being damaged due to the motor 1 being reversely driven by the synchronous generator 2, which has become a synchronous motor, due to malfunction of the governor device 16, etc. In this case, the purpose is not to detect the shearing of the shear pin that directly connects the prime mover 1 and the generator 2, as described here, and it is unreasonable to make it serve both purposes.

This invention was made to solve the above-mentioned problems, and provides protection for a power generation system that can reliably and easily detect shearing of the shear pin that directly connects the prime mover and the generator and issue an alarm. The purpose is to obtain equipment.

[Means for Solving the Problems] A protection device for a power generation system according to the present invention includes a synchronous generator rotation speed detector that detects the rotation speed of a synchronous generator, and a prime mover rotation speed detector that detects the rotation speed of a prime mover. a detector, and can compare the detection result by the rotation speed detector for the synchronous generator with the detection result by the rotation speed detector for the prime mover and output the rotation speed difference between the synchronous generator and the prime mover. This device includes a comparator and an alarm means that outputs an alarm signal indicating that the shear pin has broken when the rotational speed difference output from the comparator exceeds a predetermined value.

[Function] The power generation system protection device of the present invention utilizes the fact that when a shear pin is sheared in a coupling that directly connects a synchronous generator and a prime mover, a difference in rotational speed occurs between the synchronous generator and the prime mover. The shearing of the shear pin is detected, and an alarm is output by the alarm means. That is, the rotation speeds of the synchronous generator and the prime mover are detected by rotation speed detectors, and the difference between the detection results is obtained by a comparator. Then, in the alarm means, when the rotation speed difference output from the comparator exceeds a predetermined value, it is determined that shear bin shearing has occurred, and an alarm is output.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a prime mover 17 that drives a synchronous generator 18, and 19 a prime mover 17 and a generator 1.
This coupling part 19 directly connects the motor shaft coupling 19a, the generator shaft coupling 19b, and these couplings 19a,
Share bin 1 that can connect 19b and shear with overload torque
9c.

Further, 20 is a rotation speed detection pickup (prime mover rotation speed detector) that detects the rotation speed of the shaft of the prime mover 17, and 21 is a rotation speed inspection pickup (synchronous generator rotation speed detector) that detects the rotation speed of the shaft of the synchronous generator 18. machine rotation speed detector), 22.23
are the detection pulses from the pickups 20 and 21, respectively (
24.25 are converters (FDC) that convert the output pulses from the amplifiers 22.23 into DC outputs; 26 are DC outputs from the converters 24.25 (corresponding to the prime mover 17); rotation speed and synchronous generator 1
Compare and amplify the difference (corresponding to the rotation speed of motor 17)
27 is an auxiliary relay driven by the output from the differential amplifier 26, and 27a is a contact point of the auxiliary relay 27 to generate an alarm. It becomes an output contact. 28 is a transistor that operates in response to the output from the differential amplifier 26 to drive the auxiliary relay, and 29 is a control power supply device for the components 22 to 28 described above. In this embodiment, the auxiliary relay 27, contact 27a, and transistor 28 connect the differential amplifier 26
An alarm means is configured to output an alarm signal indicating that shearing of the share bin 19c has occurred when the output from the g-motor 17 and the synchronous generator 18 exceeds a predetermined value.

Next, the operation of the apparatus of this embodiment will be explained.

The prime mover 17 and the synchronous generator 18 are connected to the coupling part 19
In a power generation system that is directly connected to each other, under normal operating conditions, each shaft of the prime mover 17 and the synchronous generator 18 rotates at the same time. Shaft of prime mover 17 and synchronous generator 1
From the rotation speed detection pickups 20 and 21 attached to each axis of 8, pulses corresponding to the rotation speed of each axis are always obtained, and each pulse signal is amplified by amplifiers 22 and 23. Further, after being converted into a DC output by converters 24 and 25, it is guided to a differential amplifier 26.

In this differential amplifier, the difference between the output V from the converter 24 and the output 2 from the converter 25, that is, l v 1 - v21
is obtained as an output v0 by comparison and amplification. Since this differential amplifier 26 has a built-in absolute value circuit, the output v0 is V, = -IV, -V.

It is expressed as Note that K is the amplification degree of the differential amplifier 26.

Output V of the differential amplifier 26, (prime mover 17 and synchronous generator 1
8), when the shear bin 19c is sheared, the coupling part 19 between the prime mover 17 and the synchronous generator 18 is disconnected, and the pickup 20. When it is detected that the pulse difference has exceeded a predetermined value, the base current of the transistor 28 is caused to flow, thereby making conduction between the collector and emitter of the transistor 28, and activating the auxiliary relay 27. As a result, operating contact 2 of auxiliary relay 27
7a becomes operational, and an alarm output is sent to an alarm device (not shown) or the like.

As described above, according to the device of this embodiment, shearing of the shear pin 19c directly connecting the prime mover 17 and the generator 18 can be detected reliably and easily, and an alarm can be issued when shearing is detected.

In the above embodiment, the purpose is only to obtain the output of the contact 27a and take out the alarm output, but as shown in FIG. The output from the converter 24.25 may also be guided to a speed relay 32.33 to detect speed for protection during startup and operation of the power generation system. It is also possible to provide functions such as a low speed detector, a synchronous speed detector, an overspeed detector, etc.

[Effects of the Invention] As described above, according to the present invention, when the share bin is sheared in the coupling that directly connects the synchronous generator and the prime mover, a difference in rotational speed occurs between the synchronous generator and the prime mover. Since the structure is configured such that the shearing of the share bin can be detected using the system and the alarm can be outputted by the alarm means, it is possible to reliably and easily detect the shearing of the share bin that directly connects the prime mover and the generator.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a protection device for a power generation system according to an embodiment of the present invention, FIG. 2 is a block diagram showing a protection device for a power generation system according to another embodiment of the invention, and FIG. FIG. 2 is a configuration diagram showing a protection device of the system. In the figure, 17-prime mover, 18-synchronous generator, 19-
Coupling part, 19cm shear pin. 20- Pickup for rotation speed detection (rotation speed detector for M motor), 21- Pickup for rotation speed detection (rotation speed detector for synchronous generator), 26- Differential amplifier (comparator), 27-
Auxiliary relay, 27a - contact, 28 - transistor. In addition, in FIG. 1, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] In a power generation system comprising a synchronous generator and a prime mover for driving the synchronous generator, the synchronous generator and the prime mover are directly connected by a coupling having a shear pin capable of shearing with overload torque. A rotation speed detector for a synchronous generator that detects the rotation speed of the machine, and a rotation speed detector for a prime mover that detects the rotation speed of the prime mover are provided, and a detection result by the rotation speed detector for the synchronous generator and a rotation speed detector for the prime mover are provided. a comparator capable of outputting a rotation speed difference between the synchronous generator and the prime mover by comparing the detection result by the prime mover rotation speed detector; and a rotation speed difference output from the comparator that exceeds a predetermined value. 1. A protection device for a power generation system, comprising: an alarm means for outputting an alarm signal when the shear pin is sheared.