High Voltage Ride Through Strategy for Full DC Wind Power Generation System Through DC Transmission

The onshore full DC wind power generation system can effectively address the challenges of resonance and reactive power transmission in large-scale wind power AC convergence. However, the full DC wind power generation system transmitted through High-voltage direct current still carries the risk of high-voltage tripped from the grid. To handle this problem, the expression of the transient voltage at the wind power grid connection point after DC blocking is established. And the output power variation characteristics of the Grid connected inverter (GCI) are analyzed, the DC bus overvoltage mechanism is clarified. Secondly, based on the active and reactive power regulation capability of the DC/DC converter and the GCI, a coordinated control strategy for high-voltage ride-through is proposed, which focused on two perspectives: reducing the voltage at the grid connection point and mitigating the active power imbalance. Finally, a simulation model is constructed using the PSCAD/EMTDC simulation platform to verify the accuracy of the mechanism analysis and the effectiveness of the suppression strategy.