【摘要】 针对在级联功率变换器系统中由于高带宽控制的负载侧变换器具有一定的恒功率负阻抗特性,因而可能导致级联系统直流母线电压振荡,并严重影响到整个系统的控制性能和稳定运行的问题,从通过增强级联侧直流母线阻尼来抑制电压振荡的角度出发,提出一种将并联于级联侧直流母线的母线电压补偿装置(DBVC)控制为电阻性的虚拟负载的控制策略及其设计方法。利用级联变换器系统中前后级变换器的输出/输入阻抗,分析和比较了引入所述控制策略前后级联侧直流母线电压稳定性的变化情况。仿真和实验结果表明,所提出的控制方法能够有效抑制级联侧直流母线电压的振荡,可以显著改善整个级联系统的控制性能。更多还原

【Abstract】 When voltage oscillation is caused in the cascaded DC bus in a cascaded power converter system,the control performance and stability of the power converter system will be seriously deteriorated accordingly by the inherent constant power load or negative impedance characteristics of load side power converter with high control bandwidth. In order to address this problem,a control strategy is proposed.It suppressed DC bus voltage oscillation through damping enhancement by controlling the parallel DC bus voltage conditioner( DBVC) as a virtual resistor. By using the output impedance of power source converter and the input impedance of load converter,the stability of DC bus voltage was analyzed with and without the proposed control strategy. The simulation and experiment results show that the proposed method can effectively suppress DC bus voltage oscillation and improve control performance for the whole system.更多还原