稳态强磁场电源直流有源滤波技术方案的分析

Analysis of DC Active Filter for High Magnetic Field Stable Power Supply

为了满足强磁场装置电源供电极低的电流纹波要求,设计了一种直流有源滤波器。分析比较了目前国际上现有的强磁场装置电源所需的直流有源滤波器,对稳态强磁场电源采用利用并联有源滤波技术的滤波方案并给出了系统结构并对其工作原理进行了说明,论述了该系统的设计方法。根据其实际负载特性,通过检测负载端纹波电压,进而控制有源滤波器产生所需电流;通过对负载侧的滤波电容进行充、放电来调整负载端电压,实现负载电流的低纹波。基于传递函数建立该系统的数学模型并对控制系统进行详细的分析表明,该系统具有良好的快速跟踪性能及对谐波很好的抑制效果。仿真及实验结果验证了该有源滤波器的良好性能,尤其对低次谐波的抑制更为明显,为以后强磁场电源有源滤波装置提供了理论和设计依据。

A DC Active Filter （DAF） is designed for the power supply of the high magnetic field device which requires very low current ripple. A new scheme is proposed through parallel active power filter technique. This paper presents the structure, principle and design method of this system. According to the actual load nature, the DAF produces current with the control technique and compensates the ripple current by detecting the voltage of the load. The voltage of the load is adjusted by charging and discharging the capacitor on the load side with the current produced by DAF and it makes the current ripple through the load very low. This paper establishes the mathematical model of the system based on transfer function. This control system is also analyzed in detail, and it is concluded that this system can respond to the reference quickly and is effective in suppressing the ripple. Then, simulation and test results are given, which validates that this DAF is with good performance especially in suppressing low-order harmonics.