Analysis and Minimization of Harmonics on the AC and DC Sides of PWM Inverters
a School of Electrical Engineering and Informatics, Institute of Technology Bandung, Indonesia
Abstract
Voltage source inverters (VSIs) are commonly used in variable speed AC drives, Uninterruptible Power Supplies (UPS), and utility interface of renewable power generation systems. In such applications the pulsewidth modulation (PWM) technique has been accepted as a standard technique to control both output voltage and frequency. As the implementation is simpler, sampling based PWM techniques are more popular than the programmed ones. In sampling based PWM techniques, the reference or modulating signal is sampled regularly and the result is used in such a way as to control the pulsewidth of the inverter output voltage so that the average value of the output voltage is proportional to the reference signal. The most popular implementation of the sampling based PWM technique is based on the comparison between a reference and a high-frequency triangular carrier signals, which is also referred to as subharmonic or natural sampling. © Springer-Verlag Berlin Heidelberg 2012.