Xi’an High Voltage Apparatus Research Institute conducted a series of high power tests on UHV switchgears to investigate the test parameters and test circuits.The results indicate that: ①Full-pole tests of T100s and T100a are necessary to verify the thermal effect close to current zero

the insulation between bus and enclosure

and the making and breaking performance between circuit breaker contacts;②In capacitive current switching test

proper test circuit should be adopted to satisfy the request of power frequency voltage variation in order to obtain the minimum arcing time;③ In the case of series-compensation device on transmission line

additional tests must be performed for circuit breaker.In this paper

the high power tests mentioned above are described

including the test standards

test items and typical test circuits.