Protective Relay Classification

Relay protection can be categorized in various ways according to different standards. Here are several common methods of classification:

1. By the protected object:

Transmission line protection, generator protection, transformer protection, motor protection, busbar protection, etc.

2. By protection principle:

Overcurrent protection, overvoltage protection, distance protection, differential protection, zero-sequence protection, etc.

3. Categorized by the fault types reported by the protective devices:

Interspace short-circuit protection, ground fault protection, turn-to-turn short-circuit protection, out-of-step protection, overexcitation protection, etc.

4. By the implementation technology of relay protection devices:

Mechanical protection, rectifier protection, transistor protection, integrated circuit protection, microcomputer protection, etc.

5. By the protective function: main protection, backup protection, etc.