不间断电源的传导电磁骚扰特性实验研究

Experimental research of characteristics of electromagnetic conduction disturbance of uninterrupted power supply

针对不间断电源(UPS)工作时产生电磁干扰信号影响设备正常工作的问题,利用示波器、频谱仪等仪器测量UPS的传导电磁骚扰信号,分析不同工作状态下其电磁骚扰信号的频域和时域特性。研究结果表明,UPS电源在12、24、36、48 kHz等开关频率整数倍的频率处出现峰值;负载的变化对较低频率处的谐波分量的影响不大,但是会在更高的频段处(50kHz以上)产生较强的谱峰,此时信号波形畸变严重;UPS电源对电网的传导骚扰波的幅值在3～6 V之间;UPS对负载的差模电流影响比较大,离线状态对负载的影响更大。

Since electromagnetic conduction disturbance of UPS affects the normal work of the equipment, it was measured by the oscilloscope, spectrum analyzer ete, the frequency domain characteristics and time characteristics under different operating condition was analyzed. Research shows that, UPS power will appear a peak when frequency of UPS is 12kHz, 24kHz, 36kHz and 48kHz, and is integral multiple of the switching frequency. The load change have little effect on harmonic components in low frequency range, but in the higher frequency range （above 50kHz） producing a strong spectral peak. The signal waveform Severe distortion at present. UPS power conduce wave amplitude of disturbance in 3 -6V on the grid. Effect of UPS on differential mode current load is relatively large, offline for greater load effect.