Harmonic Analysis of a Synchronized Pulse-Width-Modulated Three-Phase Inverter

In pulsewidth-modulated inverters used for variable-frequency applications, a number of harmonic control policies can be used. Most of these policies are complex to implement by hardware. The most simple and yet effective technique is synchronizing or the synchronized harmonic control policy. This paper uses double Fourier analysis techniques to obtain the output harmonics as a function of pulsewidth, pulsing frequency, and output frequency. The method obtains the harmonics as analytical functions and thus provides the necessary relationships for control studies and system optimization. The more significant theoretical results are provided and theoretical and experimental results obtained from a 25-kW three-phase pulsewidth-modulated inverter, are compared.