1.引言随着国民经济与现代电子技术的迅速发展,家用电器已进入千家万户,办公自动化设备也普及到各行各业。电视机、洗衣机、空调机、节能灯、计算机、打印机、电传机、复印机等大量投入使用,人民生活质量与工作效率均得到提高。然而,此类非线性负荷却成为低压配电线路乃至电力 1. Introduction With the rapid development of the national economy and modern electronic technology, household appliances have entered millions of households, and office automation equipment has also spread to all walks of life. TV sets, washing machines, air conditioners, energy-saving lamps, computers, printers, fax machines and copiers have all been put into operation. The quality of life and work efficiency of the people have been raised. However, such non-linear loads have become low-voltage distribution lines and even electricity