モジュラー・マルチレベル・カスケード変換器（MMCC-SSBC）を用いた位相シフトPWM STATCOM

—瞬時電圧低下時の運転継続性能—

抄録

This paper provides an intensive discussion on the low-voltage-ride-through (LVRT) capability and performance of a phase-shifted PWM STATCOM using the modular multilevel cascade converter based on single-star bridge-cells (MMCC-SSBC). It follows the previous paper having focused on current control performance. This paper describes modeling, analysis, and design of the STATCOM, paying attention to the cluster-balancing control of the dc capacitor voltages. Experimental verification with a three-phase 150-V, 10-kVA downscaled model confirms that the STATCOM provides satisfactory LVRT capability against single-, double- and triple-phase voltage sags, and even against the most severe voltage sags with a voltage depth of 100%.