空调驱动器PFC电路传导干扰抑制研究与应用

Research and application of PFC circuit conducted interference suppression for air conditioner driver

功率因数校正(Power Factor Correction,PFC)电路对空调器电流谐波抑制和提高整机功率因数具有重要作用。在空调驱动器高频化、小型化发展趋势下,PFC电路的载频不断提升,目前已达到60 kHz频率,但因PFC电路高频开关导致的传导干扰问题也愈加突出。针对此问题,提出一种干扰抑制方法,通过近场耦合抑制和高频噪声吸收的方式分别对传导干扰中的差模干扰和共模干扰进行处理,降低干扰幅值。并在3匹空调整机进行验证,EMI改善前PFC传导干扰测试曲线最高点平均值相对国家标准余量为0 dB,改善后测试余量为11 dB。测试结果符合电磁兼容国标要求,验证了方法的有效性,且方法具有较好的成本优势,适合在空调产品批量应用。

PFC(Power Factor Correction)circuit plays an important role in harmonic current suppression and improving power factor for air conditioner.With the development trend of high-frequency and miniaturization of air conditioner driver,the carrier frequency of PFC circuits is constantly increasing,and currently has reached the range of 60 kHz.The issue of conducted interference caused by high-frequency switching in PFC circuits is becoming increasingly prominent.Aiming at the issue,an interference suppression method is proposed.The differential mode interference and Common-mode interference in conducted interference are respectively processed by near-field coupling suppression and high-frequency noise absorption.Based on the above methods,the amplitude of interference has been reduced.The method is proved by experiments on 3 HP air conditioner.Through these experiments,it can be seen that before the EMI improvement the average value of the highest point in the PFC conducted interference test curve has a relative margin of 0 dB to the national standard,and after adding the improvement method,the margin value is 11 dB.The test results comply with national standards,verifying the effectiveness of the method.Also,the method has low cost advantage and is suitable for mass application in air conditioner products.