Research on balance control strategy of single capacitor clamped five-level inverter clamping capacitor

A five-level inverter composed of a single capacitor clamped three-level topology and a half-bridge is introduced, and a new SPWM control strategy for this topology is proposed. The strategy uses two modulation waves with opposite directions to modulate the positive and negative half-cycle interleaved carriers. By controlling the charging and discharging times of the clamping capacitor in each carrier cycle, the voltage balance control of the clamping capacitor is achieved. At the same time, a single-phase capacitor clamped five-level inverter is taken as an example to analyse the principle of the capacitor balance control strategy in detail, and to verify the correctness and feasibility of the control strategy through simulation research and experimental results.