Research On A New Method For Operational Synthetic Test Of UHVDC Thyristor Valves

DC converter valve is the key device for HVDC project. Operationtest of converter valve can directly assessment the performance ofconverter valve under various operating conditions to ensure that thewhole converter valve HVDC transmission system is reliable. Forlarge-capacity UHVDC converter valve operation test, taking intoaccount the economy and equivalence of operation test, synthetic testmethod is an ideal method widely used now, which can significantlyreduce required power capacity required, thereby reducing the cost,improving the equivalence.Firstly, various operating conditions of HVDC converter valve weresimulated. According to the duty cycle of the converter valve, its failuremechanism is analyzed, laying the theoretical foundation for the study ofoperating test methods. According to IEC standards and the nationalstandards of China, the design of operation test methods of UHVDCconverter valve is proposed and its equivalent mechanism is analyzed.Combined with the actual parameters of UHVDC transmission project,test parameters of each operation test for UHVDC converter valves arecalculated.Secondly, the existing synthesis converter valve test equipmentsabroad are studied and its test circuit simulink modeling is carried out.The characteristics and shortcomings of these test equipments areanalyzed, which can be a reference to propose a new synthetic test circuit.Based on the research above, a new type of UHVDC converter valveoperation synthetic test circuit is proposed. Its topology and the circuittheory are analyzed. Afterwards, a physical model of the test circuit is setup and its simulink model is simulated to validate the test circuit.Experimental waveforms and simulation results of physical models arebasically consistent and the error is within13%, indicating that thesynthetic test circuit design and the pulse timing control can meet the requirements of convertor valve’s operation test.Finally, according to the operation test parameters of UHVDCconverter valves, a detailed simulation study of each operation test itemfor the new synthetic test circuit is carried out and its feasibility andequivalence is analyzed. The control mode of the test circuit is describedand the simulation waveforms and the parameters of component arepresented. Simulation and physical model studies show that design ofnew synthetic test circuit is feasible, which can meet the requirements ofoperation test. Research results can provide a refenerce to develop the testequipment for operation synthetic test of UHVDC converter valve.