The harmonic impact of variable speed air conditioners on residential power distribution

Power electronic circuits fed directly from electric utility power systems are often the source of significant harmonic currents. The susceptibility of residential power distribution systems to harmonics generated by inverter-driven variable-speed air conditioners, which are expected to see wider application in the future, is examined. In general, variable-speed air conditioners are 15-40% more energy efficient than comparable single-speed air conditioners. However, simulations indicate that harmonics produced by significant market penetration of variable-speed air conditioners may cause customer service voltage distortion levels to exceed the limits given in recently proposed standards