The stability of any power distribution system generally relies on the automatic operation of the protection system. Ensuring the protection relays at the core of this process are operating to their designed settings is the key factor to clear faults with the minimum disturbance to the rest of the network.

Modern relays are, more often than not, micro-processor based with analogue signals mimicking primary values being converted into digital signals for processing. Hardwired and digital input signals are also processed to logically control the overall operation of the network.

IEC 61850 is fast becoming the protocol in which data and messages are transmitted around the network to enable even closer and more logical discrimination times. These IED’s (Intelligent Electronic Device) are the 'smart' relays of today’s protection systems.

Communicating with these relays has become an important part of any commissioning and maintenance programs.

Writing detailed Test Plans to simulate the different functions of the relays is now considered ‘the norm’ for both operation and repeatability for future testing of the same device.

Secondary Injection simulates conditions that require an action from the relay which could be a trip of the immediate Circuit Breaker or a logic output for further action somewhere else in the network. Accurate timing is essential for the correct operation and HAOMAI secondary injection equipment can accurately verify these times.

Test reports are filed in a logical structure to enable easy access for immediate or future comparisons to fit into any asset management tool.

HAOMAI is specialized in developing, manufacturing and selling Protection Relay Test System since 1999. The relay test set model RELAYSTAR-7000A, RELAYSTAR-1600, RELAYSTAR-806, RELAYSTAR-1200, RELAYSTAR-802, RELAYSTAR-702 etc. have been sold to more than 30 different countries.