The fundamental frequency is high in static medium frequency power supply and it is incapable of achieving a no static error output by traditional control strategy. In allusion to their limitation, proportional-resonant (PR) control was proposed in this paper. The model of static medium frequency power supply was found and the principle and the characteristic and the method of design were analyzed and contrasted. Based on that, a novel strategy of dual closed-loop PR control was proposed. Simulation and experimental results verify that dual closed-loop PR control strategy effectively restrains the load disturbance, the adjustment of control parameters and bandwidth are easier and wider, and it tends to have selectivity compensate to low harmonics and feeds nonlinear loads by limiting the maximum total harmonic distortion (THD) less than 2%.%针对静止式中频电源基波频率高,传统的控制方法谐波抑制困难且难以实现无静差输出等问题,依据变压器等效理论,建立了静止式中频电源数学模型.在详细分析了比例谐振控制策略的原理和特性的基础上,提出了一种双闭环比例谐振控制策略,即负载电流内环和负载电压外环均采用比例谐振控制的算法,并结合系统稳定性判据给出了各主要控制参数的设计方法.仿真和实验结果表明,双闭环比例谐振控制策略可以有效地抑制负载扰动影响,控制器参数的调节性强,带宽调节裕度大,且对低次谐波具有选择性补偿功能,满足非线性负载要求,保证输出电压总谐波含量小于2％.
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