Research on Neutral Point Potential Balance Control of Three-Level Inverter Based on Simplified Space Vector Modulation

Regarding the traditional space vector pulse width modulation (SVPWM) algorithm, there are complex mathematical calculations in the implementation process. This paper introduces a method based on the unified voltage modulation idea of the two-level system, and converts the threelevel system into a two-level system through vector decomposition, thereby simplifying the three-level SVPWM algorithm. On this basis, the paper studies the midpoint potential imbalance problem in the diode-clamped three-level inverter. By analyzing the essential role of various vectors in affecting the midpoint potential, a dynamic balance control factor is introduced to eliminate the midpoint charge, which can effectively suppress the fluctuation of the midpoint potential. The algorithm is applied in simulations and experiments, verifying that the simplified algorithm is correct and feasible in modulation and midpoint potential balance control. This paper provides a practical solution to the complexity of traditional three-level SVPWM algorithms and the midpoint potential imbalance problem in three-level inverters.