SIMULATION AND PERFORMANCE INVESTIGATIONS OF SINGLE-PHASE HIGH POWER FACTOR RECTIFIERS

Abstract

f'he conventional converters suffer from the problem of low supply side power factor and , input current- distortion. Passive solutions offer reliable, rugged and quiet reduction of harmonic current and are insensitive to line surges and spikes -but have a number of disadvantages. These are heavy and bulky. These may be sensitive to the line frequency. The performance characteristics of some topologies belongs to 'above converter categories'. have been presented. Various new circuits and control techniques have been developed, to- improve the performance of the ac/dc converters. This dissertation discusses the operation and performance comparison of few high power-factor correction circuits. The boost type, buck type and passive rectifier type power factor - correction circuit topologies have been simulated -and their -performance' has been investigated-. The performance parameters used for comparison- are: power factor, THD, ripple factor, component count and cost of the system. The boost type power factor correction (PFC) circuits are the most popular one for moderate and high power application because it offers the better utilization of the power switches and provides the good control over the line current. The continuos nature of input current results in low - conducted electromagnetic interference compared to other active PFC topologies such as buck converters. The main drawback of the boost converter is that it doesn't limit inrush-current and doesn't provide overload protection for the converter. The buck converters are best suited for low voltage, low power applications.. This converter system limits. inrush-current and pr.,ovides overload protection for the converter and overvoltage protection to the load, which is not possible in boost converters. But it operates in discontinuous current mode and leads to significant Iine current distortion and electromagnetic interference