Design and analysis of a switching AC-AC voltage regulator

Abstract

Most regulators are designed to meet the requirements that the output voltage must be held constant within a specified tolerance for changes within a specified range in the input voltage and the output loading, the output may be required to be electrical1y isolated from the input, regulator size and weight must be reduced To appreciate the advantage of switching regulators, it is de sirable first to consider t he linear regulators. In linear regulator 50 Hz transformer is required. Such transformers are larger in size and weight compared to high frequency transformer. The transistor us ed in this regulator 0 perates in the active region, incurring significant amount of power loss. Therefore, the overal1 efficiencies of linear regulator are usual1y in a range of 30-60%. The switching regulators have high efficiency because the control1ing devices works as switches ensuring low device loss. Their output voltage can be control1ed for a wide range of input voltage variations by changing the duty cycle of the switching signal. In this thesis a switch mode ac-ac voltage regulator made of ideal switch and practical IGBT switches have been investigated. The regulator will maintain constant voltage across the load during any change in supply voltage as wel1 as for variation of load. The efficiency of this regulator is above 80%, but the input power factor is very low and needs further research to improve the input power factor to make the regulator commercial1yviable.