Control parameters design procedure for multi-converters DC power system considering dynamic interaction between converters

Due to the dynamic interaction between converters, the design of control parameters of multi-converters medium-voltage DC (MVDC) power system is much more complicated than that of a single-converter situation. The open-loop and closed-loop transfer functions considering the control-loops dynamic interaction between converters are developed, which are suitable for studying the influence of the control parameters on the system stability. With the above transfer functions, a system-level control parameters design procedure for the dynamic stability (e.g., oscillation frequency and damping factor) of the system is proposed. If there are a large number of converters, the computational burden of the system-level control parameters design procedure will be very huge. For this reason, a control parameter sharing method is further proposed in this paper, which is based on the dynamic interaction mechanism between converters. In this sharing method, the control parameters of the equivalent reduced-order model of the system are shared with each converter, so that the calculation burden of the control parameters of the system is reduced significantly. Consequently, the dynamic stability of the system can be designed by the equivalent reduced-order model. Experiments are conduced to validate the system-level control parameters design procedure.