Serhii Stepenko

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.

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.

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.

Input current parameters analysis for PFC based on quasi-resonant and conventional boost converters

This article presents a comparative analysis of the input current parameters for active power factor corrector (PFC) based on conventional boost converter (BC) and zero-current-switching quasi-resonant boost converter (ZCS-QRBC). The comparison was performed taking into account the spectral composition of the input current (individual harmonic levels, total harmonic distortion) and power factor. It has been shown that both converters rated for 1 kW output power are compliant with the requirements of international standard IEC61000-3-2.

Power Factor Corrector Based on Parallel Quasi- Resonant Pulse Converter with Fast Current Loop

Abstract The problems, devoted to power quality and particularly power factor correction, are of great importance nowadays. The key requirements, which should be satisfied according to the energy efficiency paradigm, are not limited only by high quality of the output voltage (low total harmonic distortion), but also assume minimal power losses (high efficiency) in the power factor corrector (PFC). It could be satisfied by the use of quasi-resonant pulse converter (QRPC) due to its high efficiency at high switching frequency instead of the classical pulse-width modulated (PWM) boost converter. A dynamic model of QRPC with zero current switching (ZCS) is proposed. This model takes into account the main features of QRPC-ZCS as a link of a PFC closed-loop system (discreteness, sharp changes of parameters over switching period, input voltage impact on the gain). The synthesized model is also valid for conventional parallel pulse converter over an active interval of commutation. The regulator for current loop of PFC was synthesized based on digital filter using proposed model by the criterion of fast acting.

Three-Level Neutral-Point-Clamped Quasi-Z-Source Inverter with Maximum Power Point Tracking for Photovoltaic Systems

This article is focused on a photovoltaic system based on the three-level neutral-point-clamped quasi-z-source inverter. The maximum power point tracking (MPPT) algorithm based on dP/dV feedback was used in the photovoltaic system to adjust the duration of the shoot-through states of power switches and achieve a maximum power. Proper system operation in the case of irradiance step is demonstrated by simulation in Matlab/Simulink software.

Comparison of three MPPT algorithms for three-level neutral-point-clamped qz-source inverter

This work is focused on a photovoltaic system with a three-level neutral-point-clamped quasi-z-source inverter. The maximum power point tracking algorithms based on dP/dV feedback, perturb and observe and incremental conductance have been adapted and tested in this topology using the shoot-through duty cycle as control variable. Simulation results using SimPowerSystem from Matlab/Simulink are presented.

Output filter design for grid connected single phase three-level quasi-Z-source inverter

This paper describes an output filter design for a grid connected single phase three-level neutral-point-clamped quasi-Z-source inverter. New voltage distortion approach was proposed and compared with classical solution. The simulation and experimental results are discussed.

Switch operation power losses of quasi-resonant pulse converter with parallel resonant circuit

The analysis of electromagnetic processes in power switch of a zero-current switching quasi-resonant pulse converter with parallel resonant circuit is presented in this paper. The analysis performed by stitching equations illustrating change of power switch current and power switch voltage. The obtained results for each switching interval allowed to estimate the overall power dissipation and power losses for all switching intervals.