A modified voltage measurement technique for the PSC-PWM modulated modular multilevel converters using module grouping

This paper proposes a modified sub-module voltage measurement technique for the PSC-PWM modulated modular multilevel converter (MMC) using less voltage sensors. With this technique, the sub-modules per arm are divided into several groups according to their respect carrier phase angles. This arrangement ensures that only one sensor is needed within each divided group. Therefore, the number of sensors and the complexity of the hardware are both significantly reduced when compared to the direct measurement method. Furthermore, when compared to the method using a single sensor per arm, the maximum output voltage amplitude as well as the equivalent switching frequency is lowered in every group. It means that the challenges of voltage range and the bandwidth of voltage sensors is alleviated by using the proposed measurement technique. Simulation results demonstrate the validity of the proposed method.