Half-bridge Series Resonant Converter Research Articles

An AC-DC LED Integrated Streetlight Driver with Power Factor Correction and Soft-Switching Functions

The use of light-emitting diodes (LEDs) in street lighting applications has been greatly welcomed with the current trends of energy saving, environmental protection, carbon reduction, and sustainable development. This paper presents a novel AC-DC LED integrated streetlight driver that combines an interleaved buck converter with a coupled inductor and a half-bridge series resonant converter with a full-bridge rectifier into a single-stage power conversion topology with power factor correction (PFC) and soft switching capabilities. The PFC is achieved by designing the coupling inductor in the interleaved buck converter sub-circuit in discontinuous conduction mode. In addition, the resonant tank in the half-bridge series resonant converter sub-circuit is designed to be similar to an inductive load, thus giving the power switch a zero-voltage switching (ZVS) function, decreasing switching losses and increasing the overall efficiency of the proposed circuit. A prototype circuit of the proposed LED integrated streetlight driver with a power rating of 165 W (235 V/0.7 A) and 110 V input utility voltage has been developed and tested. According to the measurement results, a power factor greater than 0.98, a total harmonic distortion coefficient of the input current less than 3%, and an efficiency greater than 89% were obtained in the AC-DC LED integrated streetlight driver. Therefore, the experimental results are satisfactory and demonstrate the functionality of the proposed AC-DC LED integrated streetlight driver.

Adaptation of Inductive Power Transfer to Small Household Appliances That Can Operate on Induction Heating Cooktops: Wireless Electric Kettle

In this paper, an inductive power transfer (IPT) system without compensation elements is presented for small house appliances. The proposed system’s transmitter side is an independent induction heating cooktop. IPT can be achieved when the kettle with the receiving coils is placed on the transmitter coil. The coils are designed with a high coupling coefficient. The magnetic system model consisting of aligned transmitter and receiver coils is created in the Maxwell program. In the created model, the analysis depends on the air gap and frequency, which are the variables that affect the wireless power transfer. The electronic circuit simulation uses the coil model to examine the system’s dynamic behavior. The design of the transmitter/receiver coils of the IPT system is made with a cylindrical coil with a diameter of 145 mm, taking into account that it is compatible with the dimensions of the existing kettle and induction heating cooktops coil. A half-bridge series resonant converter circuit is used to adjust the power transferred to the load. To verify the simulation results and test the designed system, an experimental circuit using a 2200 W kettle is carried out. In the experiments, the air gap between the coils is kept constant at 7 mm, and measurements are taken for different powers. Experimental results confirm the magnetic model and simulation results. As a result, wireless power transfer is realized in a wide range without loss of performance in the kettle. System efficiency is greater than the 90% specified in the Ki cordless kitchen standard, and the harmonic currents drawn from the mains are lower than the values determined by the IEC 61000-3-2 standard.

Dual Output and Dual-Frequency Resonant Inverter-based Induction Heating Using ADC Control

A dual output dual-frequency (DODF) resonant converter-based AC-AC induction heating (IH) by using asymmetrical duty cycle (ADC) control is presented in this paper. The proposed scheme gives two outputs with independent power control, which improves input power factor and achieves zero voltage switching (ZVS) with a wide range of operations. It includes two pairs of two half-bridge series resonant converters, each pair having one common capacitor along with various resonant frequencies. These converters are modulated with the ADC control scheme to obtain smooth operation. The proposed topology doesn’t use the DC stage; it is directly connected to the power supply to produce high-frequency AC output. With the use of direct connection, the converter components are reduced when compared to conventional converters. There will be a reduction in voltage drop, power losses, cost of the converter and which will result in improved efficiency. Simulation results are obtained from PSIM 11.1.7 software. This scheme controls two different loads with an efficiency of 98.25%.

Independently Controllable Dual-Output Half-Bridge Series Resonant Converter for LED Driver Application

This article presents a dual-output series resonant converter (SRC)-based light-emitting diode (LED) driver, which utilizes three switches to form two half-bridge networks. The proposed three-switch two-half-bridge structure provides reduced switch count and independent control. It uses asymmetric duty cycle control to regulate the LED operating currents and utilizes a low-frequency pulsewidth modulation (PWM) dimming scheme for each half-bridge to control the illumination of each LED load independently. All the switches in the proposed converter operate with zero-voltage turn-on to reduce the switching losses. The operating principle and detailed analysis of the proposed converter is presented and verified with experimental studies for a total load of 50 W (i.e., LED load-1 26 W and LED load-2 24 W). Also, a comprehensive comparative study of the proposed LED driver with recent counterparts is presented.

Load Estimation for Induction Heating Cookers Based on Series RLC Natural Resonant Current

In domestic induction heating applications, cookware can be considered an equivalent load in a series resistor–inductor–capacitor resonant converter. Therefore, the electrical parameters of an equivalent circuit change according to the cookware material, size and the cookware position on the heating coil. This study proposes an online estimation method for detecting the cookware status, determining the material and estimating the equivalent heating resistance of cookware on an induction heating cooker (IHC) for power control. The proposed method could turn off the circuit in abnormal situations such as low equivalent heating coverage rate or non-ferromagnetic cookware and adjust the power in normal situations. In the method, a half-bridge series resonant converter (HBSRC) generates two test patterns with three resonant voltage pulses to detect cookware every 10 ms, only the current feedback information is needed to avoid the calculation loads and times necessary for complex signal operations in software. To verify the proposed method, a digital signal processor based HBSRC with 1000 W was constructed. The maximum errors between the estimated and measured resistance and inductance were 7.14% and 2.91%, respectively. Moreover, power control in emulated user operation reveal that the proposed method and control system can effectively estimate load online to detect cookware status and determine whether to turn off or vary the heating power for an IHC.

Interleaved LLC half-bridge series resonant converter with integrated transformer

ABSTRACT High efficiency and simple structure are the main reasons for the widespread use of LLC converters. Nowadays, the application of LLC converters is still in development. In general, increasing the power level to use a parallel converter is quite popular. However, this method uses a separate transformer, which will lead to an obvious decrease in power density. Moreover, the separate transformer will also cause current imbalance due to the error of the magnetic material characteristic. Therefore, this study proposes an integrated transformer for a conventional interleaved LLC converter. This proposed structure can effectively increase the power density and decrease the problem of current imbalance. The operating principle of the interleaved LLC converter and an analysis of the integrated transformer are presented. Finally, experimental results are recorded for a prototype converter. The specifications are as follows: DC input voltage is 380 VDC, output voltage is 12 VDC, maximum output current is 50 A, output power is 600 W, and maximum conversion efficiency is approximately 95.5%.

A Nonisolated Wide Input Series Resonant Converter for Automotive LED Lighting System

In this article, a reconfigurable nonisolated buck–boost (BB) integrated full-bridge series resonant converter (FBSRC) based light emitting diode (LED) driver is proposed for wide input voltage automotive lighting applications. The proposed LED driver is derived by the integration of BB operation with FBSRC. It can be reconfigured into three different resonant converter topologies such as BB integrated FBSRC, BB integrated half-bridge series resonant converter (BB-HBSRC), and conventional HBSRC and, hence, produces three levels of voltage gains. By transformation from one topology to other based on the input voltage range and with asymmetrical pulsewidth modulation control, it can operate for wide input voltage range while maintaining the soft switching. The main advantages of the proposed configuration are smooth transformation into three different topologies without any additional switching devices, no topological transitions within a switching cycle in steady state, use of simple proportional–integral controller, soft switching, and wider voltage gain with buck/boost operation. In addition, dimming control is also achieved using pulsewidth modulation technique. Detailed theoretical analysis of the proposed converter is presented. To verify the analysis and performance, a prototype of 22.7 W, 22.5 V LED driver is designed, simulated, and tested for a wide input voltage range of 18 to 120 V.

Analysis and Evaluation of WBG Power Device in High Frequency Induction Heating Application

A device suitability analysis is performed herein by comparing the performance of a silicon carbide (SiC) metal-oxide-semiconductor-field-effect transistor (MOSFET) and a gallium nitride (GaN) high-electron mobility transistor (HEMT), which are wide-bandgap (WBG) power semiconductor devices in induction heating (IH) systems. The WBG device presents advantages such as high-speed switching owing to its excellent physical properties, and when it is applied to the IH system, a high output power can be achieved through high-frequency driving. To exploit these advantages effectively, a suitability analysis comparing SiC and GaN with IH systems is required. In this study, SiC MOSFET and GaN HEMT are applied to the general half-bridge series resonant converter topology, and comparisons of the conduction loss, switching loss, reverse conduction loss, and thermal performance considering the characteristics of the device and the system conditions are performed. Accordingly, the device suitability in an IH system is analyzed. To verify the device conformance analysis, a resonant converter prototype with SiC and GaN rated at 650 V is constructed. The analysis is verified by an experimental comparison of power loss and thermal performance.

Analysis and Design of APWM Half-Bridge Series Resonant Converter With Magnetizing Current Assisted ZVS

In an asymmetrical pulse-width-modulated half-bridge (APWM HB) series resonant converter, an auxiliary LC network is provided for ensuring zero-voltage switching (ZVS) over a wide range of line and load variations. However, it comes at the cost of increased number of components and reduced efficiency and reliability. This paper presents a novel design methodology for the standard APWM HB resonant topology, which uses the magnetizing current and eliminates the need for extra components. The converter with the proposed design methodology operates at the resonant frequency of the tank and features load-independent ZVS for a wide range of input voltage variation with minimal magnetizing current. Empirical formulae are derived to design the resonant network and the magnetizing inductance of the high-frequency transformer systematically in a flowchart-based manner. The proposed design is validated by using simulations as well as experiments and is compared with a reference APWM HB series resonant converter design that uses an auxiliary LC circuit for ZVS. Two separate experimental prototypes of the two converters rated for 30 W, 48 V/5 V with a switching frequency of 500 kHz were built and tested in the laboratory. It was found that the converter with the proposed design methodology, apart from having lower component count, is about 3% more efficient than the reference topology at the rated power.

A Single-Stage LED Tube Lamp Driver with Power-Factor Corrections and Soft Switching for Energy-Saving Indoor Lighting Applications

This paper presents a single-stage alternating current (AC)/direct current (DC) light-emitting diode (LED) tube lamp driver for energy-saving indoor lighting applications; this driver features power-factor corrections and soft switching, and also integrates a dual buck-boost converter with coupled inductors and a half-bridge series resonant converter cascaded with a bridge rectifier into a single-stage power-conversion topology. The features of the presented driver are high efficiency (>91%), satisfying power factor (PF > 0.96), low input-current total-harmonic distortion (THD < 10%), low output voltage ripple factor (<7.5%), low output current ripple factor (<8%), and zero-voltage switching (ZVS) obtained on both power switches. Operational principles are described in detail, and experimental results obtained from an 18 W-rated LED tube lamp for T8/T10 fluorescent lamp replacements with input utility-line voltages ranging from 100 V to 120 V have demonstrated the functionality of the presented driver suitable for indoor lighting applications.

Design and testing of 45 kV, 50 kHz pulse power supply for dielectric barrier discharges.

The design, construction, and testing of high frequency, high voltage pulse power supply are reported. The purpose of the power supply is to generate dielectric barrier discharges for industrial applications. The power supply is compact and has the advantage of low cost, over current protection, and convenient control for voltage and frequency selection. The power supply can generate high voltage pulses of up to 45 kV at the repetitive frequency range of 1 kHz-50 kHz with 1.2 kW input power. The output current of the power supply is limited to 500 mA. The pulse rise time and fall time are less than 2 μs and the pulse width is 2 μs. The power supply is short circuit proof and can withstand variable plasma load conditions. The power supply mainly consists of a half bridge series resonant converter to charge an intermediate capacitor, which discharges through a step-up transformer at high frequency to generate high voltage pulses. Semiconductor switches and amorphous cores are used for power modulation at higher frequencies. The power supply is tested with quartz tube dielectric barrier discharge load and worked stably. The design details and the performance of the power supply on no load and dielectric barrier discharge load are presented.

A Single-Stage LED Tube Lamp Driver with Input-Current Shaping for Energy-Efficient Indoor Lighting Applications

This study proposes a single-stage light-emitting diode (LED) tube lamp driver with input-current shaping for T8/T10-type fluorescent lamp replacements. The proposed AC–DC LED driver integrates a dual-boost converter with coupled inductors and a half-bridge series-resonant converter with a bridge rectifier into a single-stage power conversion topology. This paper presents the operational principles and design considerations for one T8-type 18 W-rated LED tube lamp with line input voltages ranging from 100 V rms to 120 V rms. Experimental results for the prototype driver show that the highest power factor (PF = 0.988), lowest input current total harmonic distortion (THD = 7.22%), and highest circuit efficiency (η = 92.42%) are obtained at an input voltage of 120 V. Hence, the proposed driver is feasible for use in energy-efficient indoor lighting applications.

Double modulation control scheme for a DC/DC converter applied to a battery charger

In this study, a novel control scheme for controlling a self-oscillating half-bridge series resonant converter for DC source and secondary battery interface is proposed. This new control scheme is used to control and regulate the DC output current of the converter. The proposed control scheme has the advantages of not only wide power regulation range, but also ease of output current control. In addition, it can achieve a stable and efficient zero-voltage-switching (ZVS) in a whole load range. The control principles of the proposed method are described in detail and its validity is verified through simulated and experimental results based on a 24 V 125 Ah battery charger. The maximum charging efficiency of the proposed topology during the overall charging period exceeds 90%.

A Modified Asymmetrical Self-Oscillating DC/DC Half Bridge Converter

This paper presents a simple novel technique in order to modifying the conventional self oscillating half-bridge series resonant converter which does not allow the control of the power transfer into a self oscillating half-bridge series resonant converter which allows the power transfer control. The proposed new technique consists in controlling the magnetic saturation of a saturable transformer, by using a DC-control current circulating through an additional winding, in order to ensure a variable asymmetrical control as a function of the dc-control current. We can therefore control and regulate the output power while maintaining the switching frequency close to the resonant one. A 600 W, 300 V input, and 24 V output laboratory prototype operating at 110 kHz is built and tested to verify the effectiveness of the proposed converter

Resonant inverting-buck converter

This study presents a new resonant inverting step-down DC-DC converter. A half-bridge inverter and an LC resonant tank are employed. The resonant tank is the medium of energy transfer and provides soft-switching conditions at turn-on and turn-off switching instants for all active elements. The voltage conversion ratio is adjustable, and the converter is automatically shut down at output short circuit. Its characteristics are very similar to half-bridge series-resonant converter, except that input and output terminals possess common ground and voltage gain up to unity can be achieved at discontinuous conduction mode. Practical results from a laboratory prototype verify the presented theoretical analysis.

Generation of Pulsed Electric Fields for Processing Microbes

This paper first reviews viable microbe processing mechanism and then presents generation of pulsed electric fields for processing microbes. Microbe processing includes food sterilization, waste treatment, pollution control, and medical diagnostics and treatment. To generate pulsed electric fields for achieving sterilization, a generated high dc output voltage is chopped into pulsed waveforms, in which their pulse-width varies from tens of nanoseconds to hundreds of microseconds, period changes from 0.1 to 1 ms, and electric field intensity is from tens to hundreds of kV/cm. In this study, we propose wide pulses stacked with narrow pulses to prevent undesired air breakdown and reduce power consumption. Modified half-bridge series resonant converters are used to generate high dc voltages. They are operated at high frequency, in discontinuous conduction mode and with a PWM control; therefore, its weight and size can be reduced significantly and its efficiency can be correspondingly improved.

Control Circuitry for a Partial Series Resonant Converter

A control circuit for a new high-frequency DC-DC converter, suitable for application in a few kilowatts range, is presented. The converter topology is based on a half bridge series resonant converter, i. e. having only two switches. Resonance occurs only for a part of each switching cycle, and a discrete energy pulse is transferred to the load every half cycle, rendering a variable frequency controller for controlling the output power. The converter features zero-voltage turn-on and snubbed turn-off at reduced current for the switching devices, and zero current commutation of the rectifier diodes, making it suitable for IGBT switches operating at a switching frequency higher than 20 kHz. The efficiency of the converter is supposed very high under full load and low load conditions, while the dynamic output voltage range is two times larger than that of the conventional half bridge Series Resonant Converter. PSpice Model presents the entire converter and control circuit.

Performance characteristics of a half-bridge type series resonant dc-dc converter with auxiliary switches

Performance characteristics of a half-bridge type series resonant dc-dc converter with auxiliary switches

The zero voltage switching partial series resonant converter

A new high-frequency dc to dc converter, suitable for application in the kilowatt range, is presented. The topology is based on a half bridge series resonant converter, i.e., having only two switches. Resonance occurs only for a part of each switching cycle, and a discrete energy pulse is transferred to the load every half cycle, rendering a variable frequency controller for controlling the output power. The converter features zero-voltage turn-on, and snubbed turn-off at reduced current for the switching devices, and zero current commutation of the rectifier diodes, making it suitable for IGBT switches operating at a switching frequency higher than 20 kHz. The efficiency of the converter is very high under full load and low load conditions, while the dynamic output voltage range is two times larger than that of the conventional half bridge Series Resonant Converter.

A Normalized Model for the Half-Bridge Series Resonant Converter

Closed-form steady-state equations are derived for the halfbridge series resonant converter with a rectified (dc) load. Normalized curves for various currents and voltages are then plotted as a function of the circuit parameters. Experimental results based on a 10-kHz converter are presented for comparison with the calculations.