Research on the SVPWM Strategy for Single-phase Five-level Hybrid Bridge Inverters

Regarding the topology of a single-phase five-level hybrid bridge inverter composed of T-type bridge arms and half-bridge arms, the commonly used space vector pulse width modulation(SVPWM) modulation technique in three-phase systems is applied to this topology. The SVPWM control model for this topology is constructed. Compared to sinusoidal pulse width modulation(SPWM) modulation technique, SVPWM control model enables the output electrical energy to have lower harmonic content and is more easily controlled digitally. First, the different switch states and their SPWM modulation strategies for this topology are analyzed. Then, based on the different switch states, the space vectors are divided into sectors and appropriate switch vectors are selected according to the principle of minimum switch losses to establish the SVPWM control model. Finally, Matlab/Simulink is used to compare the simulation of this topology using both SPWM modulation and SVPWM modulation, and an experimental platform is built to validate the inverter topology. The results show that the proposed SVPWM control model has lower current harmonics than SPWM modulation.