The comparative studies of 3 - phase controlled AC - DC converters with high quality input currents

Abstract

The main aims of Power Electronics are the studies about how to reduce size and weight, improve quality and efficiency of power electronic devices by improving power switches characteristics and decreasing the cost of such units' production. As the number of nonlinear load increases, the problem of electrical energy quality becomes more and more significant by means of current and voltage distortion and low power factor among the high power consumers. Traditionally this problem was solved using passive filters and filter-compensator devices. However, the latest Power Electronics achievements in area of creation high power full-controlled switches such as MOSFET and IGBT are able to solve this problem by active control of reactive power with a high frequency pulse control. The actual problem is the production of 3-phase high power AC converters, although single-phase cases are widely investigated. I. Introduction owadays the actual problem is development N the high - power 3-phase AC converters. The main disadvantage of such systems is low power factor due to the presence of DC - link such as diode bridge circuit with capacitor as a filter. In order to reduce this disadvantage different structures of power factor correctors are used, But instead all the merits such as good efficiency, power factor, specific power and reactive elements volume, these circuits have a set of disadvantages that makes further development rather difficult. II. The analysis of 3- phase controlled AC/CD converters based on widely known circuits (boost converter, inverse converter, and Cook's converter) The principal circuits of the converters mentioned above are shown in Fig. 1