Control Strategy of Parallel Unidirectional Controlled Rectifiers for Reactive Power Compensation

Aiming at the limited RPC capability in unidirectional controlled rectifiers due to the inherent restriction of current distortion, a new solution for incorporating RPC functionality into unidirectional controlled rectifiers is proposed by this paper, in which multiple unidirectional rectifiers are connected in parallel, some of them are required to provide reactive power to the grid, while the remaining one are used to compensate current zero crossing distortion. By this way, the RPC capability of the unidirectional rectifiers could be effectively enhanced. The control strategy corresponding to the solution is discussed in detail by this paper. Simulation results are presented which verified the feasibility and effectiveness of the proposed solution and the corresponding control method.