Control Strategy for Voltage Profile Improvement of VSC-MVDC System in Urban Power Grid

As one of the essential infrastructures in the metropolis, the urban power grid provides a continuous and reliable power supply to meet the growing energy demands of urban populations. However, with the increased integration of renewable energy and various types of loads, the operation stability and flexibility of the urban power grid are challenged. The application of the Voltage Source Converter based Medium-voltage direct current (VSC-MVDC) system into the urban power grid provides a new choice for urban power grid upgrading. In the traditional VSC-MVDC system control of the urban power grid, the system aims to provide constant active and reactive power from one terminal to the other. However, these control strategies may waste the support capacity of the VSC-MVDC system. In this paper, a novel voltage profile improvement control strategy is proposed. Compared to the traditional voltage control of the VSC-MVDC system, the proposed voltage profile improvement control strategy could provide more reactive power to the AC system under disturbance. The different simulation cases in PSCAD/EMTDC verify the performance of the proposed voltage profile improvement control strategy.