Research on Fault Ride-Through of A Direct-Series DSSC With Fault Current Limiting Function

Direct-series distributed static synchronous series compensator (DSSC), when the controlled line short-circuit fault occurs, its core component converter is affected by the fault current, resulting in the DSSC out of operation, which may further deteriorate the stability of the system. In this paper, a direct-series DSSC with short-circuit limiting function (DSSC- FCL) topology is proposed, and its working principle is analyzed in detail, the parameter design principle of DSSC-FCL is given, and a fault ride-through strategy based on DSSC-FCL is proposed. Finally, simulation results show that the proposed direct-series DSSC-FCL has the power flow control function under normal working conditions. In the event of a fault in the AC system, the fault ride-through strategy proposed in this paper can effectively suppress the AC current and DC capacitor current of the device, protecting the direct-series DSSC from the impact of large short-circuit currents in the system. Additionally, after the fault is cleared, the strategy shortens the device's response time, thereby increasing the reliability and operational efficiency of the device.