scope:

Introduction

This application guide for the relay protection of synchronous generators presents a review of the generally accepted forms of protection for the generator and its excitation system. It summarizes the use of relays and devices, and serves as a guide for the selection of equipment to obtain adequate protection. The guide is primarily concerned with protection against faults and abnormal operating conditions for large hydraulic, steam, and combustion-turbine generators.

This guide does not purport to detail the protective requirements of all generators in every situation. Standby and emergency use generators are specifically excluded. The suggestions made pertain to typical generator installations. However, sufficient background information relating to protection requirements, applications, and setting philosophy is given to enable the reader to evaluate the need, to select, and to apply suitable protection for most situations.