Fixed-frequency Control Strategies Research Articles

Primary side control strategies for battery charging regulation in wireless power transfer systems for EV applications

AbstractResonant inductive‐based wireless power transfer (WPT) for battery charging has potential applications in electric vehicles (EVs). The EV battery charging process requires the regulation of both charging voltage and current. Duty ratio or frequency control is generally preferred to manage the power flow between the transmitter and receiver coils in the WPT system. In the case of WPT charging, misalignment between the coils and parameter variations are unavoidable issues that result in changes to the output power. Therefore, it is essential to control the power flow to maintain constant current (CC) and constant voltage (CV) modes during battery charging. To address these challenges, various primary‐side control techniques, such as asymmetric clamped mode (ACM), asymmetric duty cycle (ADC), and phase‐shift (PS) fixed frequency control strategies, have been proposed for WPT systems. This paper conducts a comparative analysis of these control methods, considering their output voltage ranges and their ability to maintain zero‐voltage switching (ZVS) for the entire control range. Furthermore, the paper presents a generalized design for reduced‐order small signal modelling, utilizing an extended describing function. The designed controller, based on small signal modelling, will undergo real‐time testing to evaluate its dynamic performance in the series‐series resonant converter.

Fixed-frequency control strategies for a series resonant inverter for induction heating - comparison of properties

Three fixed-frequency control strategies for a series resonant inverter for induction heating: PS-PWM, ADC and ACM have been compared in the paper. The analysis has been carried out using decomposition of the inverter output voltage to harmonic components. Special attention has been paid to the determination of conditions assuring ZVS operation of the semiconductor devices and to the inverter efficiency. Streszczenie. W artykule porownano wlaściwości trzech staloczestliwościowych metod sterowania rezonansowego falownika szeregowego do nagrzewania indukcyjnego: ADC, PS-PWM i ACM. Analize przeprowadzono z wykorzystaniem rozkladu napiecia wyjściowego falownika na skladowe harmoniczne. Szczegolną uwage zwrocono na określenie warunkow zapewniających przelączanie zaworow przy zerowym napieciu (ZVS) oraz sprawnośc falownika. (Staloczestotliwościowe metody sterowania rezonansowego falownika szeregowego do nagrzewania indukcyjnego – porownanie wlaściwości)

CFAVC scheme for high frequency series resonant inverter-fed domestic induction heating system

This article presents the investigations on the constant frequency asymmetric voltage cancellation control in the AC–AC resonant converter-fed domestic induction heating system. Conventional fixed frequency control techniques used in the high frequency converters lead to non-zero voltage switching operation and reduced output power. The proposed control technique produces higher output power than the conventional fixed-frequency control strategies. In this control technique, zero-voltage-switching operation is maintained during different duty cycle operation for reduction in the switching losses. Complete analysis of the induction heating power supply system with asymmetric voltage cancellation control is discussed in this article. Simulation and experimental study on constant frequency asymmetric voltage cancellation (CFAVC)-controlled full bridge series resonant inverter is performed. Time domain simulation results for the open and closed loop of the system are obtained using MATLAB simulation tool. The simulation results prove the control of voltage and power in a wide range. PID controller-based closed loop control system achieves the voltage regulation of the proposed system for the step change in load. Hardware implementation of the system under CFAVC control is done using the embedded controller. The simulation and experimental results validate the performance of the CFAVC control technique for series resonant-based induction cooking system.

Asymmetrical Voltage-Cancellation Control for Full-Bridge Series Resonant Inverters

This paper presents and analyzes the asymmetrical voltage-cancellation (AVC) control, a generalized control technique for resonant inverters. It is applied to the popular full-bridge series resonant inverter. The proposed control technique achieves better efficiency performances than conventional fixed-frequency control strategies, while considering zero-voltage-switching operation, output power and load variations. The theoretical results are verified experimentally, using a prototype for an induction-heating cooking appliance.