Mitigation of Electromagnetic Interference in Pulse Width Modulated Voltage Source Inverters and Communication Enhancement in Power Lines

Most of the modern society's conveniences depend on electrical energy. The power supplied by the system can be considered as raw power and often it must be conditioned according to the application. The conditioning process is done by power electronic converters using semiconductor switches. This work involves the operation of pulse width modulated inverters. Because of the high switching rate of the semiconductor switches harmonics are generated in the output voltage and current of the inverter. These harmonics result in propagation of electromagnetic noise in the power electronic system. This work explains how the harmonic pollution can be mitigated by randomizing the switching period of the pulse width modulated inverter. In particular, an advanced spectral shaping technique is presented, which produces spectral nulls at selected frequencies. The spectral nulls can then be used as communication channels in power line communication systems.