辅助谐振变换极逆变器的中点电压稳定控制策略

Control Strategy for Neutral Point Voltage Stability of Auxiliary Resonant Commutated Pole Inverter

辅助谐振变换极逆变器(ARCP)在高频大功率领域具有高效率和低损耗的优势。然而实际应用中,中点电压偏移问题会使ARCP软开关失败率增加。文中针对ARCP母线分压电容中点电压偏移以及中点电压偏移导致的主开关管零电压开通失败的问题,提出了一种中点电压自抗扰控制策略。分析了母线电容等效串联电阻(ESR)对中点电压和交流侧电压的影响,建立了可变时序控制模式下包含母线电容ESR的中点电压模型。在此基础上设计了中点电压自抗扰控制器,利用辅助管控制过充电调节时间,实现了三相辅助支路谐振电感电流平衡,达到了中点电压稳定、主开关管零电压开通和提高逆变器效率的目标。与PI控制模式下97.0%的逆变器效率相比,自抗扰控制模式在最大功率下可达97.5%的逆变器效率。该控制策略无需改变电路结构,易于实现。仿真和实验结果验证了所提控制策略的有效性。

Auxiliary resonant transform pole inverter(ARCP)has the advantages of high efficiency and low loss in high frequency and high power field.However,in practical application,the problem of neutral point voltage devia⁃tion will lead to the increase of failure rate of ARCP soft switch.In this paper,a neutral point voltage active distur⁃bance rejection control strategy was proposed to solve the problem of neutral point voltage deviation of ARCP bus di⁃vider capacitor and the failure of zero voltage opening of main switch tube caused by neutral point voltage devia⁃tion.The influence of bus capacitor equivalent series resistance(ESR)on neutral point voltage and AC side voltage was analyzed,and a neutral point voltage model including bus capacitor ESR in variable sequential control mode was established.On this basis,the neutral point voltage active disturbance rejection controller was designed and the auxiliary tube was used to control the overcharge regulation time,which realize the current balance of the threephase auxiliary branch resonant inductor,achieving the goal of neutral point voltage stability,zero voltage opening of the main switching tube and improving the efficiency of the inverter.Compared with 97.0%inverter efficiency in PI control mode,active disturbance rejection control mode can achieve 97.5%inverter efficiency at maximum power.The control strategy is easy to implement as it doesn’t need to change the circuit structure.The effective⁃ness of the proposed control strategy was verified by simulation and experimental results.