Integrated test system of flexible DC control and protection based on modelling and decoupling

Due to the use of turn-off device IGBT in flexible HVDC transmission, the fault current is a short time change process. In the initial stage of flexible DC protection failure, if the converter valve cannot be quickly closed and the AC test switch cannot be turned off, it will bring great harm to the converter equipment. At present, the test of flexible DC control protection mainly depends on RTDS or PSCAD simulation test. This testing method needs to build a very complex test environment, and the workload of on-site configuration and debugging is very huge. Therefore, this paper establishes an integrated test system of flexible DC control and protection based on modelling decoupling to solve the above problems. The integrated test system realizes the field testing of flexible DC protection control systems with different configurations, which greatly reduces the workload of on-site debugging personnel and improves the safe and stable operation ability of the power grid.