一种高速SRG功率变换器及其CCM风电控制

A POWER CONVERTER FOR HIGH SPEED SRG AND ITS CONTROL OF WIND POWER GENERATION IN CCM

提出一种无主开关管的新型开关磁阻发电机(SRG)功率变换器拓扑,在高速运行和连续导通模式(CCM)下分析其励磁和发电两阶段工作过程,并与通过开关角控制的经典不对称半桥功率变换器进行对比,发现两者的励磁和发电工作过程基本相同。进一步通过仿真和实验,获得新型功率变换器在高速CCM时的相电压、相电流等结果与理论分析相吻合,并获得转速、励磁电压、发电电压、功率四者的约束关系,从而优化输出功率时可采用调节励磁电压和发电电压的方式,相比于不对称半桥功率变换器,两者的发电输出能力相当。最后,以变速风电应用为例,给出控制策略,无需转子位置检测和风速检测,基速以上无桨距角调节,证实了所提新型功率变换器及其控制策略在高速CCM运行时的有效性。

A switch less power converter topology for SRG is proposed in this paper.Under high-speed operation and continuous conduction mode(CCM),the working process of excitation stage and generation stage of the new power converter is analyzed.At the same time,compared with the traditional asymmetrical half-bridge power converter based on the switching angle control,the same results of excitation and power generation processes are obtained.According to the simulation and experimental results,the phase voltage and phase current of the new power converter at high speed CCM are consistent with the theoretical analysis.The constraints of speed,excitation voltage,generation voltage and power are obtained,and then the output power can be optimized by adjusting the excitation voltage and generation voltage.Compared with the asymmetric half-bridge power converter controlled by switching angle,the new power converter has the same generation capacity.Finally,taking the application of variable speed wind power as an example,the control strategy is given,without rotor position detection and wind speed detection,and without pitch angle adjustment above the base speed.The simulation results show the effectiveness of the proposed power converter and its control strategy in high-speed CCM operation.