Minh-Khai Nguyen

Single-Phase AC–AC Converter Based on Quasi-Z-Source Topology

This paper deals with a new family of single-phase ac-ac converters called single-phase quasi-Z-source ac-ac converters. The proposed converter inherits all the advantages of the traditional single-phase Z-source ac-ac converter, which can realize buck-boost, reversing, or maintaining the phase angle. In addition, the proposed converter has the unique features that the input voltage and output voltage share the same ground and the operation is in the continuous current mode. The operating principles of the proposed converter are described, and a circuit analysis is provided. In order to verify the performance of the proposed converter, a laboratory prototype was constructed with a voltage of 84 Vrms/60 Hz. The simulation and experimental results verified that the converter has a lower input current total harmonic distortion and higher input power factor in comparison with the conventional single-phase Z-source ac-ac converter.

A Single-Phase Z-Source Buck–Boost Matrix Converter

This paper proposes a new type of converter called a single-phase Z-source buck-boost matrix converter. The converter can buck and boost with step-changed frequency, and both the frequency and the voltage can be stepped up or stepped down. In addition, the converter employs a safe-commutation strategy to conduct along a continuous current path, which results in the elimination of voltage spikes on switches without the need for a snubber circuit. The operating principles of the proposed single-phase Z-source buck-boost matrix converter are described, and a circuit analysis is provided. To verify the performance of the proposed converter, a laboratory prototype was constructed with a voltage of 40 Vrms/60 Hz and a passive RL load. The simulation and the experimental results verified that the converter can produce an output voltage with three different frequencies 120, 60, and 30 Hz, and that the amplitude of the output voltage can be bucked and boosted.

Single-phase AC/AC converter based on quasi-Z-source topology

This paper deals with a new family of single-phase ac-ac converters called single-phase quasi-Z-source ac-ac converters. The proposed converter inherits all the advantages of the traditional single-phase Z-source ac-ac converter, which can realize buck-boost, reversing, or maintaining the phase angle. In addition, the proposed converter has the unique features that the input voltage and output voltage share the same ground and the operation is in the continuous current mode. The operating principles of the proposed converter are described, and a circuit analysis is provided. In order to verify the performance of the proposed converter, a laboratory prototype was constructed with a voltage of 84 Vrms/60 Hz. The simulation and experimental results verified that the converter has a lower input current total harmonic distortion and higher input power factor in comparison with the conventional single-phase Z-source ac-ac converter.

Single-Phase Z-Source Buck-Boost Matrix Converter

In this paper, a new converter called single-phase Z-source buck-boost matrix converter is presented. This converter can buck and boost with variable frequency, in which the frequency and voltage can be step-up/down. In addition, a safe-commutation strategy is used to conduct continuous current path which resulting in eliminating current and voltage spikes on switches. The operating principles, analysis, and experimental results of the proposed SZMC are described.

Single-phase Z-source voltage sag/swell compensator

This paper deals with a new topology based on single-phase Z-source AC/AC converter for voltage swells or sags compensation. The proposed system is able to compensate voltage swells. In addition, it is also able to compensate up to over 50% voltage sag. A commutation strategy to drive the AC/AC converter is employed to realize snubberless operation. Analysis is presented; Simulation and experimental results at 20% voltage swell and 60% voltage sag are shown.

Single-phase quasi-Z-source AC-AC converter with safe-commutation strategy

Single-phase quasi-Z-source AC-AC converter has a lower input current total harmonic distortion, higher input power factor and higher efficiency in comparison with the conventional single-phase Z-source AC-AC converter. This paper presents a safe-commutation strategy for the single-phase quasi-Z-source AC-AC converter. The converter only uses four switches without the use of a snubber circuit. The operating principle and steady-state analysis are presented. The experimental results show that the use of safe-commutation strategy is a significant improvement as it makes it possible to avoid voltage spikes on the switches.

Single-phase quasi-Z-source AC/AC converter

This paper proposes a novel single-phase quasi-Z-source AC/AC converter (qZSAC). Compared to traditional single-phase Z-source AC/AC converter, the proposed qZSAC has following features: the input voltage and output voltage is sharing the same ground; the operation is in continuous current mode (CCM). The proposed qZSAC can control to shape the input current to be sinusoidal and in phase with the input voltage. The operating principles, simulation results are presented. To verify these described performance features, PSIM simulation and experimental results were performed with a low total harmonic distortion of input current and high input power factor.

Three-phase AC-AC Z-source converter (TPZC) with maximum boost voltage ratio

This paper deals with a new topology for three-phase ac-ac Z-source converter. Unlike other configurations, the proposed three-phase ac-ac Z-source converter has the capability to achieve maximum boot voltage ratio about 2. Injected capacitors are used to transfer energy to Z-source inductors in shoot-through state. Thus, the maximum output voltage gain can obtain. By controlling the duty cycle, the proposed three-phase ac-ac Z-source converter can provide buck-boost function, overcome voltage sag or voltage surge in power system. The operating principles, analysis and simulation results of the proposed three-phase ac-ac Z-source converter are presented.