Quasi-resonant Zero Current Switching Research Articles

Quasi Resonant Zero Current Switching Modified Boost Converter (QRZCSMBC)

The inrush current of the Boost converter can reach high values when attached to a stable input source like a car battery or a battery buffered micro-grid. To avoid the inrush current, a modification of the converter by placing the capacitor between the output and input can be done. To reduce the switching losses, the quasi resonant zero current switching QRZCS concept is used. The active switch of the converter has a constant on-time and a variable off-time or frequency. The inrush current is studied and the function of the QRZCS converter is treated with the help of mathematical descriptions and with the uZi diagram. LTSpice simulations are used to prove the considerations.

High-Voltage Power Supply for High Repetitive Rate Marx Generator with Quasi-Resonant Zero-Current Switching Transistor Control Algorithm

Due to having a number of advantages, Marx generators are still the most widely used devices for generating high-voltage pulses in many fields of science and technology. To ensure their proper operation, especially when the generation of many frequent, highly repetitive pulses is required, a highly efficient high-voltage power supply is needed. The paper describes a specially developed power supply (input voltage 48 V DC, output voltage up to 50 kV) based on the conventional Full Bridge topology with two high-frequency high-voltage transformers and a 6-stage voltage multiplier. In order to avoid many problems caused by low coupling between primary and secondary windings of the transformers and the large parasitic capacitances of the secondary windings, a special quasi-resonant zero-current switching transistor control algorithm with variable switching frequency (dependent on output load) was developed. In the described method, the energy is supplied to the transformer in short pulses, when a pair of diagonal transistors of the full-bridge converter were turned on. Then, the freewheeling state is maintained until all of the energy stored in the leakage inductance of the transformer has been transferred to the secondary side, which means that the current in the primary windings drops to zero. This approach reduces energy losses, electromagnetic disturbances and prevents current distortion in primary winding.

Design and Implementation of an Active Clamped Full Wave Quasi Resonant ZCS Boost Converter

This paper presents a closed loop control of an active-clamped full-wave quasi-resonant boost converter with zero-current-switching (ZCS) for power factor correction. Possibility to incorporate higherswitching frequency and has some potency to reduce switching losses. Power factor improvement and high efficiency is achieved with a constant output voltage and DC output voltage is regulated by using closed loop control .The concept of the proposed switchingscheme results lesser switching loss, higher efficiency, possibility to have higher switching frequency, and has potential to reduce converter's conducted EMI. This paper also presents voltage regulation using closed loop system and the simulation results are verified.

Solar Power Based PMSM Drive Employed in Refrigeration Plants for Isolated Areas

This paper presents design, modeling, and control of a quasi-resonant zero-current switching boost converter used in a photovoltaic (PV) power based surface-mounted permanent magnet synchronous motor (SPMSM) for driving compressor loads of a refrigeration plant situated in remote locations. The solar-based refrigeration system is an attractive solution as cooling burden matches with the peak incident solar radiation. The field-oriented controlled voltage source inverter is employed for speed control of the SPMSM drive under variation in solar irradiation. The MATLAB/SIMULINK environment is used to model the control of a PV power based SPMSM drive. The performance of the developed system is investigated under wide changes in operating conditions. A prototype of an 800 W PV power based SPMSM drive is developed in the laboratory to validate the simulation results.

Multiphase Zero-Current Switching Bidirectional Converters and Battery Energy Storage Application

A multiphase quasi-resonant (QR) zero-current switching (ZCS) switched capacitor (SC) bidirectional dc-dc converter structure is proposed to reduce current ripple and switching loss, and significantly increase converter efficiency and power density. This approach provides a more precise output voltage to obtain voltage conversion ratios from the double-mode versus half-mode to <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -mode versus 1/ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> mode. This is accomplished by adding a different number of switched capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The size and cost can be reduced when the proposed converter is designed with coupled inductors. Simulation and experimental results demonstrate four-phase with and without coupled inductor interleaved QR ZCS SC converter performance for bidirectional power flow control applications. A battery energy storage system for a bidirectional power flow control application is demonstrated.

Analysis, design and implementation of fuzzy logic controlled quasi-resonant zero-current switching switched-capacitor bidirectional converter

The proposed fuzzy logic controlled (FLC) system can be considered as a soft switching technique that substantially reduces the switching loss and hence attains higher efficiency by the switching capacitor converter. The proposed frequency modulation FLC quasi-resonant zero-current switching switched-capacitor (SC) converter is a new type of bidirectional power flow control conversion scheme. This device provides voltage conversion ratios from double-mode against half-mode to n-mode against 1/n-mode by adding a different number of SCs and power semiconductor switches with a small series-connected resonant inductor for forward and reverse schemes. The state-space modelling and analysis for the designed FLC take advantage of cybernetics theory. The dynamic simulation and experiments for the proposed FLC for the studied converters are used to demonstrate the validity of the constructed model under different energy conversion topologies and load conditions.

Multiple output zero-current switching switched-capacitor bidirectional dc–dc converter

The proposed circuit is a multiple output quasi-resonant (QR) zero-current switching (ZCS) switched-capacitor (SC) converter with a bidirectional power flow control conversion scheme. The principles of the proposed multiple output QR ZCS SC bidirectional dc–dc converter are described using a detailed circuit model for analysis. Simulation and experimental results are carried out to verify the validity and the soft switching performance of the proposed converter. The maximum efficiency achievable is about 94 and 92% for the forward and reverse power flow control schemes, respectively. The output voltage can be regulated by changing the switching frequency for the designed compensated closed-loop controller.

Switched-capacitor bi-directional converter performance comparison with and without quasi-resonant zero-current switching

The proposed quasi-resonant (QR) zero-current switching (ZCS) switched-capacitor (SC) converter is a new type of bi-directional power flow control conversion scheme. This device provides voltage conversion ratios from 2 against 1/2 (double-mode/half-mode) to n against 1/n (n-mode/1/n-mode) by adding a different number of SCs and power multi-oxide-semiconductor field-effect-transistor (MOSFET) switches with a small series-connected resonant inductor for forward and reverse schemes. The proposed QR SC converter presents low current stress and balanced resonant current advantages. The operating principle and theoretical analysis of the proposed bi-directional power conversion scheme are described in detail with circuit model analysis. The proposed device is compared with the conventional SC converter. Simulations and experimental verification are carried out to verify and compare the proposed QR ZCS SC bi-directional converter performance with the conventional device. At maximum efficiency, the proposed device can achieve 96% and 93% for the forward and reverse power flow control schemes, respectively.

Inverting Quasi-Resonant Switched-Capacitor Bidirectional Converter and Its Appication to Battery Equalization

The proposed quasi-resonant (QR) zero current switching (ZCS) switched-capacitor (SC) converter is a new type of bidirectional power flow control conversion scheme. The proposed converter is able to provide voltage conversion ratios from $-$3/$-$${1 \over 3}$ (triple-mode/trisection-mode) to $-n/-$${1 \over n}$ ($-$n-mode/$-$${1 \over n}$-mode) by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse power flow control schemes. It possesses the advantages of low switching losses and current stress in this QR ZCS SC converter. The principle of operation, theoretical analysis of the proposed triple-mode/trisection-mode bidirectional power conversion scheme is described in detail with circuit model analysis. Simulation and experimental studies are carried out to verify the performance of the proposed inverting type ZCS SC QR bidirectional converter. The proposed converters can be applied to battery equalization for battery management system (BMS).

Adaptive Pulse Synchronizing Control for High-Power-Factor Operation of Variable Speed DC-Drive

This paper presents a new scheme for adaptive automatic synchronization of variable high frequency (HF) control pulses with the single phase ac line. The application of this scheme is made for pulsewidth modulation (PWM) control of single-switch, quasi-resonant zero-current-switched (QRZCS), ac-dc converters. The objective is to propose a converter, to improve the performance of dc-drive and input power quality, with minimum complexity. Adaptive pulse synchronizing control scheme gives nonfluctuating dc output voltage for driving dc-motor with low source-current harmonics. Design of passive components, analysis, control and experimental results of proposed dc-drive and its comparison with low frequency (LF) hard-switched dc-drive are given. Experimental results show that the application of the proposed synchronizing control based HF quasi-resonant zero-current switching (QRZCS) converters for dc-drive gives high-power-factor operation, lower harmonic distortion, better transient response and non fluctuating motor speeds.

Quasi-Resonant Zero-Current-Switching Bidirectional Converter for Battery Equalization Applications

A systematic approach to reform and analyze a soft-switching bidirectional dc-to-dc converter is proposed for cell voltage balancing control in a series connected battery string. quasi-resonant converter circuits have been designed to achieve the zero-current-switching (ZCS) to reduce the switching loss in bidirectional battery equalizers. The results indicate that the switching loss and energy transfer efficiency can be substantially improved using the quasi-resonant ZCS (QRZCS) technology in a battery charging system with an individual cell equalizer (ICE). The validity of the battery equalization is further verified using an experimental installation involving a battery string of three lithium-ion cells. The simulation and experimental results show that the proposed QRZCS battery equalization schemes can achieve bidirectional battery equalization performance and reduce the MOSFET transistor switch power losses by more than 96% and increase the efficiency by around 20%~30% compared with the conventional battery equalizer during an identical equalization process