Power plant control system

Abstract

To provide a power generation plant control device in which, even when an instantaneous operation by a protect circuit of a main transformer occurs, a turn-off operation of a main transformer breaker and a stop operation of a power generator motor are both surely performed so that cooperation between a transformer protect circuit and a power generator protect circuit can be achieved.SOLUTION: On condition that a motor stop command relay (87T1Y) 103 is operated and a main transformer breaker turn-off command relay (1861) 104 is operated, an emergency stop operation relay (86-1) 107 is operated. Thus, after a trip command for a main transformer breaker (CB221) 4 is issued, a stop sequence of a power generator motor (M2) that is in a driven state is started. A turn-off operation of the main transformer breaker (CB221) 4 is followed by a stop operation of the power generator motor (M2). Accordingly, inconvenience that current continues flowing through the power generator motor (M2) after start of the stop sequence of the power generator motor (M2) can be avoided, whereby a failure in the power generator motor can be avoided.SELECTED DRAWING: Figure 1

Claims

1. A main transformer to which the main circuits of multiple generator motors are connected in parallel, a main transformer circuit breaker connecting the main transformer to the power system, parallel circuit breakers provided in each of the main circuits that can interrupt the power supply to the generator motors, and current transformers provided on the side of the main transformer circuit breaker away from the main transformer and on the main transformer side of each parallel circuit breaker, A fault detection relay that detects a fault based on the current detected by the current transformer, An auxiliary fault detection relay that maintains an operating state after the operation of the fault detection relay and after a predetermined fault duration, A GM stop command relay is connected in series with the fault detection auxiliary relay and sends a stop command to the driving generator motor after the fault detection relay has been activated and a time shorter than the predetermined fault duration has elapsed, A stop sequence start relay that initiates the stop sequence of the drive-state generator motor after the operation of the GM stop command relay, A relay for issuing a main transformer circuit breaker trip command, which is connected in series with the fault detection auxiliary relay and sends a trip command to the main transformer circuit breaker after the fault detection relay has been operated and a time has elapsed longer than the predetermined fault duration, A power plant control device having, A power plant control device characterized in that it activates the stop sequence start relay based on the operation of the GM stop command relay and the operation of the main transformer circuit breaker off command relay, thereby starting the stop sequence of the generator motor.

2. The power plant control device according to claim 1, further comprising a parallel circuit breaker off command relay that sends an off command to the parallel circuit breaker after the operation of the stop sequence start relay.

3. The power plant control device according to claim 1 or 2, characterized in that the stop sequence involves opening the parallel circuit breaker, closing the guide vanes, closing the inlet valve, and stopping the field circuit.

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