Static relays 

Advantages of static relays

 •  Due to the amplification of energizing signals obtainable, the sources need only provide low power. Therefore the size of the associated current and voltage transformers could be reduced.

 • Improved accuracy and selectivity.

 • Fast operation of relays and hence fast clearance of faults.

 • Flexibility of circuitry would allow new and improved characteristics.

 • The relays would be unaffected by the number of operations.

 Basic circuits employed

 • Timers

 • Phase comparators

 • Amplitude Comparator

 • Level detectors

 • Integrators

 • Polarity detectors

 High reliability operational amplifiers are used for realizing the basic components of static relays