In order to study the valve section operation test method of HVDC flexible valves under the condition of unequal number of power modules

the calculation models of test loop current and power module voltage are established

and valve section operation test method in the condition of unequal number of power modules is proposed

through analyzing the power module bypass test procedure during the valve section operation test.The test method is simulated by using PSIM simulation software and applied in the practical valve section test.Both the simulation and test results indicate that the test method proposed in the paper is able to achieve the MMC valve section test under the condition of unequal number of power modules

and satisfied the test requirements.