单相H6拓扑离网型逆变器无死区控制方法仿真研究

Research of Non-dead-time Control Method on Single-phase Off-grid Inverter Based on H6 Topology

提出了一种基于H6拓扑的无死区控制方法,通过检测输出电压、电感电流的大小和方向,在输出电压与电感电流同向时调制桥臂开关管,反向时调制续流开关管,而在电压、电流过零点附近仍然加入死区,以确保直流母线不会短路,由控制模块计算后进而调整开关管的开关状态,消除绝大多数死区时间的加入。在MATLAB/Simulink环境下构建了基于H6拓扑的单相离网型逆变器电压电流双闭环无死区控制方法仿真模型。仿真结果表明,与传统有死区控制相比,无死区控制方法能够显著提高直流母线电压利用率,降低输出电压总谐波畸变率(THD)。

A novel non-dead-time control strategy based on H6 topology was proposed. Through detecting the value and direction of the output voltage and current of inductor, the power switches of bridge arm were modulated if they were in the same direction, and the freewheeling switches were modulated if they were opposite. In order to protect the DC bus voltage from shorting out, the dead time should be added during the zero-crossing of voltage and current. And the states of switches were adjusted by calculation of the control module. Then most dead time eouM be eliminated. The simulation model for the single-phase off-grid inverter based on H6 topology was constructed in MATLAB/Simulink circumstance, in which the non-dead-time control with voltage and current double closed loop was applied. Simulation results show that, compared with dead-time control, the new control method can significantly improve the utilization of DC bus voltage and reduce Total Harmonic Distortion （THD） of output voltage.