A Neutral‐Point Voltage Balance Control Method With Simplified Voltage Sensing for Three‐Phase Three‐Level Inverters

ABSTRACT Three‐phase, three‐level inverters are widely employed in various applications due to their advantages in harmonic reduction, voltage stress mitigation, and improved electromagnetic compatibility. However, the voltage imbalance between two DC‐link capacitors caused by asymmetric charging remains a challenge for effective operation. Conventional methods typically rely on direct sampling the voltages of split capacitor or additional hardware balancing circuits, which introduces a trade‐off between reliability and cost. This paper proposes a neutral‐point (NP) voltage balancing method based on predictive current control with simplified voltage sampling. By analyzing the distortion of synthesized voltage vector caused by the capacitor voltage imbalance, a judgment angle is derived from phase current tracking errors to identify the NP voltage polarity. The proposed approach eliminates redundant hardware components and requires low computational effort, making it suitable for applications with basic inverter control requirements. Experimental results from a 320‐V/20‐kHz prototype demonstrate that the voltage difference between split capacitors can be balanced under various operating conditions, thereby validating the effectiveness of the proposed method.