Oleksandr Husev

New Shoot-Through Control Methods for qZSI-Based DC/DC Converters

Shoot-through control methods for qZSI-based dc/dc converters are presented and studied. The major goal was to increase efficiency. A new modulation technique, pulse width modulation (PWM) with shifted shoot-through, is compared with the conventional PWM shoot-through control method. The new method reduces switching frequency of bottom side transistors and inherently features partial soft switching. Previous studies have shown that the biggest drawback of PWM control with shoot-through is unequal switching frequencies of transistors. One solution to that problem could be signal swapping that has been proposed by the authors of this paper. All control methods are first simulated and then experimentally verified on a test prototype.

Single phase three-level quasi-z-source inverter with a new boost modulation technique

This paper describes a new modulation technique for a single phase three-level neutral-point-clamped qZS inverter. The proposed converter is intended for applications that require input voltage gain and high quality of the output voltage. The simulation and experimental results are presented and discussed.

Galvanically Isolated Quasi-Z-Source DC–DC Converter With a Novel ZVS and ZCS Technique

This paper focuses on the galvanically isolated quasi-Z-source dc-dc converter with a novel zero voltage and zero current switching technique. The unique feature of the impedance network lies in combining the buck-boost operation capability with the short- and open-circuit immunity of transistors; at the same time, it can perform zero voltage and zero current switching on the primary side. The boundary conduction mode of the current in the second inductor of the quasi-Z-source network was used along with snubber capacitors in the two out of four transistors and a special control algorithm to achieve full zero-switching operation of the inverter. Simulation and experimental results prove the discussed ideas. Possible modifications of the algorithm and future applications are also described.

CCM operation analysis of the single-phase three-level quasi-Z-source inverter

This paper presents a CCM analysis of a new modification of a three-level single phase neutral-point-clamped inverter. The proposed topology combines advantages of the three-level neutral-point-clamped full-bridge inverter with those of the quasi-Z-source inverter. The three-level neutral-point-clamped quasi-Z-source inverter is especially suitable for renewable energy sources. The steady-state analysis of a three-level neutral-point-clamped quasi-Z-source inverter in the case of the continuous conduction mode is presented. The conditions of the continuous conduction mode are obtained and analyzed.

Experimental Investigation of high frequency 3L-NPC qZS inverter for photovoltaic application

This paper presents an experimental investigation of a single phase three-level neutral-point-clamped quasi-Z-source inverter for photovoltaic application. The prototype and the case study system are described. Experimental results along with theoretical losses analysis are discussed. The implemented maximum power point tracking algorithm was verified in a real photovoltaic system.

New high-gain step-up DC/DC converter with high-frequency isolation

This paper presents a new step-up DC/DC converter topology. The converter is intended for applications that require a high gain of the input voltage and galvanic isolation, i.e. power conditioning systems for alternative energy sources such as fuel cells. The operation principle of the converter is explained by help of a steady state analysis. Simulation results are presented and analyzed. Finally, the experimental results are provided and a modification possibility of the proposed converter is discussed.

A review of non-isolated bidirectional dc-dc converters for energy storage systems

There is a growing interest in bidirectional dc-dc converters for interface battery with energy source and load. This paper provides a comprehensive review of non-isolated bidirectional dc-dc converter topologies. The classification and description of each type presented is based on the features and applications. This review paper is intended as a convenient reference to future non-isolated converter users. The most promising converters in terms of their simplicity, flexibility, and high efficiency are singled out.

Dynamic behaviour of qZS-based bi-directional DC/DC converter in supercapacitor charging mode

This paper presents a bi-directional quasi-Z-source inverter (qZSI) based DC/DC converter for supercapacitor (SC) interfacing in high power applications. In the SC charging mode the proposed converter acts as a conventional VSI based step-down converter, but in the energy recovery mode it acts as a qZSI-based step-up DC/DC converter. The paper analyzes and discusses the operation of the converter in the SC charging mode. The analysis of the static model of the converter as well as the Bode diagram are presented. Theoretical results are verified by experimental results on a 500 W prototype converter.

FPGA control of the neutral point clamped quasi-Z-source inverter

The three-level neutral point clamped quasi-Z-source inverter has been proposed recently. Due to its features the neutral point clamped quasi-Z-source inverter is especially suitable for renewable energy sources. This topology requires special control methods and respectively new element basis can be used for control implementation. Current paper describes the control system implemented, based on FPGA for a three-level neutral point clamped quasi-Z-source inverter and the control signals obtained.

Novel family of quasi-Z-source DC/DC converters derived from current-fed push-pull converters

This paper is devoted to the step-up quasi-Z-source dc/dc push-pull converter family. The topologies in the family are derived from the isolated boost converter family by replacing input inductors with the quasi-Z-source network. Two new topologies are proposed, analyzed and compared. Theoretical predictions are verified by means of simulations.