With the development of HVDC technology

the power rating of HVDC valve has increased rapidly. Limited by generating capacity

traditional back-to-back test circuit is difficult to fulfill the demand of valve test. With voltage source and current source individually

synthetic-test circuit can provide voltage and current for test valve by controlling the switch of aided valves. So

synthetic-test circuit is a good alternative for valve test. The hardware structure

operation principle and software configuration of the synthetic-test control and protection system are introduced. The experiment results demonstrate that the system can meet the various requirements in applications satisfactorily.