Performance Investigation of Three-Phase Three-Switch Direct PWM AC/AC Voltage Converters

Abstract

Reducing the number of active switches is substantial for obtaining a simple, reliable, highefficiency, and cost-effective AC/AC voltage converter. In this paper, two topologies of three-phase direct PWM AC/AC voltage converter are proposed. The first is for the buck converter and the other is for the boost one. Each converter has no DC energy storage elements and employs only three IGBTs. The proposed converters do not use lossy snubber circuits and have not commutation problems. A simple, reliable, and cost-effective control strategy, which employs only one voltage sensor, is also proposed. Using a closedloop voltage control technique, two complementary PWM gate signals are generated to drive the three active switches of each converter. Adjusting the duty ratio of PWM gate signals regulates the output voltage of the AC/AC converters. Operating principle and mathematical analysis of the converters are presented. Voltage stresses across active and passive semiconductor switches of the proposed converters are derived. Small signal analysis based on complex DQ transformed equivalent circuits of the converter is introduced. Voltage controller design using frequency response analysis is provided. The converters are simulated using MATLAB/SIMULINK and laboratory prototypes are implemented in real-time using DSP-DS1104 control board. The converters are tested under different operating conditions and their performances are investigated and compared. The symmetry of the output voltage/current is examined by the theory of symmetrical components. The simulation and experimental results are in a close agreement. This confirms the validity of the theoretical analysis, the effectiveness of the control strategy, and the feasibility of the proposed converters.INDEX TERMS AC-AC voltage converters, control design, small signal analysis, stability analysis, symmetrical components, voltage stress.

Configurations, Power Topologies and Applications of Hybrid Distribution Transformers

“…In these cases, the output voltage is proportional to the input voltage, according to its voltage gain characteristic. Since the switches are commutated simultaneously, reduced switch configurations can be utilized [90,91]. On the other hand, a certain degree of phase control can be provided if harmonic injection methods are utilized, such as Dual Virtual Quadrature Sources (DVQS), which increases the power converter regulation capabilities [92].…”

Power Factor Correction of Three-Phase PWM AC Chopper Fed Induction Motor Drive System Using HBCC Technique

“…An extinction angle control technique for PF improvement of a single-phase AC voltage controller fed an IM is presented in [19]. Different topologies of three phase PWM AC chopper in different applications are presented in [20]- [23]. A three phase PWM AC chopper, has eight IGBTs, feeds an IM is presented in [24].…”