ABSTRACT
This chapter introduces the single-phase and three-phase inverters and explains the challenges in meeting harmonic performance requirements. The six-step operation of the three-phase inverter produces large harmonics of the load voltages. In order to compare the results from different pulse width modulation (PWM) methods and different power converters, several performance indices are defined based on frequency analysis. The great advantage of the PWM algorithm is its ability to control the content in fundamental voltage across the load. The main constraint for PWM generation is the need to produce a symmetrical set of voltages on the load. A coefficient regarding current harmonics would better define the performance of a PWM method. The application of PWM methods in different industrial systems aims to improve global harmonic factors, reduce losses in the power converter or load, reduce torque pulsations in the motor drive applications, and reduce noise and vibrations.
