基于模拟退火算法的共模电磁干扰抑制技术

Common Mode EMI Suppression Based on Simulated Annealing Algorithm

共模电磁干扰对消抑制中,检测和补偿电路的滞后响应将大大影响补偿效果。针对这一问题,提出了数字化闭环控制共模电流并联有源补偿技术,采用共模电流能量作为共模噪声评估指标;研究了共模电流能量与补偿电流滞后时间的关系。结果表明存在多个局部最小值,提出利用模拟退火算法(SAA)寻找全局最优值的控制策略。仿真结果表明,SAA能够较好地避免搜索陷入局部最小值,有效地衰减共模噪声能量。将基于SAA的共模电磁干扰抑制技术应用于单相半桥逆变器,实验结果表明共模电流在10MHz范围内整体下降了10～15dB,有效地抑制了逆变器的电磁干扰水平,证明了该抑制技术是正确和有效的。

In common mode electromagnetic interference （EMI） compensatory suppression technique, the delay response of detecting and compensating circuit will impact the effect of common mode current suppression. A parallel active common mode EMI reduction technology with digital closed loop control is presented. A novel evolution measurement for common mode noise using common mode current energy is proposed. The relationship between CM current energy and lag time of compensatory current is studied. A simulated annealing algorithm is used to search global optimum of common mode current energy. Simulation results show that common mode EMI suppression technology based on simulated annealing algorithm （SAA） can avoid trapping into local minimal energy values and reduce common mode current energy efficiently. The proposed technology is applied in a single-phase half-bridge inverter. Experimental results show common mode current is attenuated 10~ 15 dB in the range of 10MHz, and EMI level of inverter is suppressed efficiently. It is proved that suppression method based on simulated annealing algorithm is valid and effective.