Hybrid Multifunctional Arc Suppression Inverter With Its Steady and Transient State Operation Optimization Method

A hybrid arc suppression device (HASD) is a state-of-the-art device that can work for arc suppression, reactive power compensation, and fault regulation. However, the transient problem is prominent when HASD switches modes. In addition, the active power is consumed by HASD during single line-to-ground (SLG) faults, and additional dc power supply devices are normally required for HASD. To greatly reduce the cost of HASD, a dc-link voltage control strategy based on the additional loop is proposed in this article. Compared with the traditional strategy, the proposed control strategy can absorb the active power from the power grid without adding additional dc power supply devices. Second, a transient state optimization method is proposed to realize the flexible transition between different functions of HASD. The command value of arc suppression current is increased from 0 to the maximum value during flexible switching, which reduces the transient voltage and the operational stability of HASD is apparently enhanced. Moreover, the correctness, feasibility and effectiveness of the proposed methods are verified by the simulation and experiment results. The corresponding results show that HASD achieves superior steady and transient performance when the proposed operation optimization method is adopted.