Contactor Relay Shanghai Liangxin Electrical Co., Ltd. Nader

Why should a relay protection device be added in a substation?

Adding relay protection device in substation can send out fault signal and cut off fault line in time to reduce the occurrence of substation fault, so as to ensure the reliable power supply of users and enterprises. System diagram of 110kV substation. Three-stage current protection diagram. Content may be subject to copyright.

What protection functions are used in this relay?

The following protection functions are used in this relay. 1. Under Voltage Protection: Under voltages occur due to several reasons like any faults on the system; increase in the amount of loading, loss of an incoming transformer, etc.

Why do we need protective relays?

The selection and applications of protective relays and their associated schemes shall achieve reliability, security, speed and properly coordinated. Meanwhile, protective devices have also gone through significant advancements from the electromechanical devices to the multifunctional, numerical devices of present day.

What is a relay installation?

A general term applied to a relay installation to indicate that the switching device is located physically at a point remote from the initiating protective relay, device, or source of release power or all these. Note: This installation is commonly called transfer trip when a communication channel is used to transmit the signal for remote hipping.

How did relays work in the era of electromagnetic relays?

In the era of electromagnetic relays, settings were done by tap adjustment. Repeat relays and hard wired logics were used to provide interlocking and control functionality.

What are repeat relays & hard wired logics used for?

Repeat relays and hard wired logics were used to provide interlocking and control functionality. In Section 15.2 of the IEEE Brown BookTM (IEEE Std 399) it was stated that whether the coordination is done manually or by computer, it is necessary for the engineer to “describe” the system.