Substation Substation relay can malfunction during operation

Substation Substation relay can malfunction during operation (three-phase short circuit, two-phase short circuit, single-phase, etc.) and abnormal phenomena (overload, over-voltage, low-voltage, low-frequency , gas, over-temperature, control and measuring circuit disconnection, etc.), quickly issued a trip command to the selective removal or failure alarm,  air circuit breaker  the scope of power failures caused by the extent of damage and electrical equipment, to ensure stable operation of the power system.  electric meter  Substation protection is based on a failure occurs during operation occurs when the current increases, the voltage  Circuit breaker  or decrease the frequency decreases, there gas, temperature and other phenomena over relay setting value (given value) or overrun value, in the setting time, a choice has issued a trip command or alarm signal.