A large number of reactive power are needed to be supplemented in the operation of rectifier station and inverter station in the HVDC project and

at the same time

the harmonic of converting device generated in the operation can cause reduction of power quality and interference of communication system.Therefore

the filter with corresponding capacity is needed to be installed on both AC and DC side for the reactive compensation and harmonic compression.AC filter is an important and indispensable part of UHVDC converter stations.For assuring smooth commissioning of AC filter at converter station

the EMTPE program is used to predict overvoltage of 750 kV AC filter.During the commissioning at AC site of certain converter station

12 groups of AC filter are subject to the switching test respectively.The insulation

protection and switching feature of the AC filter are checked by the test

and the data in the test is record and analyzed.It is shown by the simulation that the simulation calculation and the actual measurement are basically in agreement.The closing resistor of 750 kV circuit breaker

in case of removal from operation

has a definite influence on the inrush current of filter.