Improved Space Vector Modulation of Single-Phase ANPC Three-Level Converter with Balanced Loss Distribution

Aiming at the single-phase full-bridge active neutral-point clamped (ANPC) converter, the traditional space vector modulation (SVPWM) method has the problem of unbalanced loss of internal and external switching devices. Based on the analysis of the switching process, a loss model is established, and a loss-balanced space vector modulation is proposed. When the output voltage of the bridge leg is clamped to the neutral point, the chosen switching states are used to synthesise the reference space vector, therefore the current is freewheeled through the dual commutation loops, thus effectively making the switching loss between the inner switching devices more balanced. Compared with the traditional modulation method, the proposed method can balance the loss while taking into account its operating efficiency, and fully exploit the advantages of the ANPC converter. Finally, simulation and experiment results show that the method is simple to implement, and can effectively balance the loss of switching devices.