Showing papers on "Converters published in 2013"

Fundamentals of Power Electronics

Abstract: This chapter gives a description and overview of power electronic technologies including a description of the fundamental systems that are the building blocks of power electronic systems. Technologies that are described include: power semiconductor switching devices, converter circuits that process energy from one DC level to another DC level, converters that produce variable frequency from DC sources, principles of rectifying AC input voltage in uncontrolled DC output voltage and their extension to controlled rectifiers, converters that convert to AC from DC (inverters) or from AC with fixed or variable output frequency (AC controllers, DC–DC–AC converters, matrix converters, or cycloconverters). The chapter also covers control of power converters with focus on pulse width modulation (PWM) control techniques.

Design and Implementation of a Highly Efficient Three-Level T-Type Converter for Low-Voltage Applications

Abstract: The demand for lightweight converters with high control performance and low acoustic noise led to an increase in switching frequencies of hard switched two-level low-voltage 3-phase converters over the last years. For high switching frequencies, converter efficiency suffers and can be kept high only by employing cost intensive switch technology such as SiC diodes or CoolMOS switches; therefore, conventional IGBT technology still prevails. In this paper, the alternative of using three-level converters for low-voltage applications is addressed. The performance and the competitiveness of the three-level T-type converter (3LT2C) is analyzed in detail and underlined with a hardware prototype. The 3LT2 C basically combines the positive aspects of the two-level converter such as low conduction losses, small part count and a simple operation principle with the advantages of the three-level converter such as low switching losses and superior output voltage quality. It is, therefore, considered to be a real alternative to two-level converters for certain low-voltage applications.

Dynamic Analysis of Modular Multilevel Converters

Abstract: Theory for the dynamics of modular multilevel converters is developed in this paper. It is shown that the sum capacitor voltage in each arm often can be considered instead of the individual capacitor voltages, thereby significantly reducing the complexity of the system model. Two selections of the so-called insertion indices, which both compensate for the sum-capacitor-voltage ripples, are considered. The dynamic systems which respectively result from these selections are analyzed. An effective dc-bus model, which takes into account the contribution from the submodule capacitors, is obtained. Finally, explicit formulas for the stationary sum-capacitor-voltage ripples are derived.

A New Droop Control Method for the Autonomous Operation of Distributed Energy Resource Interface Converters

Abstract: Microgrid is widely accepted as an effective mean of integrating various distributed energy resources (DERs) through their interface converters to provide electric power of high quality and reliability. These distributed resources interface converters can operate in an autonomous fashion without any communication for enhanced system reliability and reduced complexity. Conventionally, the real power-frequency droop control and the reactive power-voltage magnitude droop are adopted as the decentralized control strategies in these DERs interface converters for the autonomous power sharing operations. However, the reactive power sharing of $Q\hbox{--}V$ droop control often deteriorates due to its dependence on the line impedances. In this paper, a $Q\hbox{--}\dot{V}$ droop control method with $\dot{V}$ restoration mechanism is proposed to improve reactive power sharing. Its operation principle and control method are explained and analyzed. Simulation and experimental results are presented to validate the effectiveness of the proposed method.

Comparative Evaluation of Advanced Three-Phase Three-Level Inverter/Converter Topologies Against Two-Level Systems

Abstract: Efficient energy conversion in low-voltage applications has gained more attention due to increasing energy costs and environmental issues. Accordingly, three-level converters have been discussed as an alternative to the standard two-level voltage-source converter because they offer an increased efficiency at higher switching frequencies. From a system perspective, the benefits of using three-level converters are not only limited to the converter itself, but there are additional positive impacts on the surrounding such as on the load machine losses or on the electromagnetic interference input filter volume. In this paper, a holistic comparison of advanced three-level topologies against the two-level topology is given. Simple analytical calculations and measurements show the benefits and the optimization potential concerning several aspects, such as the necessary semiconductor chip area, the harmonic losses in the load machine and in filter components, and the volume of passive components.

Architectures and Control of Submodule Integrated DC–DC Converters for Photovoltaic Applications

Abstract: This paper describes photovoltaic (PV) module architectures with parallel-connected submodule-integrated dc-dc converters (subMICs) that improve efficiency of energy capture in the presence of partial shading or other mismatch conditions. The subMICs are bidirectional isolated dc-dc converters capable of injecting or subtracting currents to balance the module substring voltages. When no mismatches are present, the subMICs are simply shut down, resulting in zero insertion losses. It is shown that the objective of minimum subMIC power processing can be solved as a linear programming problem. A simple close-to-optimal distributed control approach is presented that allows autonomous subMIC control without the need for a central controller or any communication among the subMICs. Furthermore, the proposed control approach is well suited for an isolated-port architecture, which yields additional practical advantages including reduced subMIC power and voltage ratings. The architectures and the control approach are validated by simulations and experimental results using three bidirectional flyback subMICs attached to a standard 180-W, 72-cell PV module, yielding greater than 98% module-level power processing efficiency for a mismatch less than 25%.

Analysis and Comparison of Medium Voltage High Power DC/DC Converters for Offshore Wind Energy Systems

Abstract: Offshore wind farm with an internal medium-voltage dc (MVDC)-grid collection connected HVDC transmission may be an option to harvest offshore wind energy. High-power MV dc/dc converters with high-step-up conversion ratios are the key components for the internal MVDC grid. In this paper, a high-efficiency step-up resonant switched-capacitor converter for offshore wind energy system is studied, which is characterized by the soft-switching condition for all switches and diodes. This significantly reduces switching losses and higher switching frequency is feasible to reduce the overall system volume and weight. The comparisons with other two kinds of topologies are also presented; moreover, the possible specification requirements of high power MV dc/dc converters are analyzed and set. The operation principle of the proposed converter has been successfully verified by simulation and experiment results.

Resonant Switched-Capacitor Converters for Sub-module Distributed Photovoltaic Power Management

Abstract: This paper discusses the theory and implementation of a class of distributed power converters for photovoltaic (PV) energy optimization. Resonant switched-capacitor converters are configured in parallel with strings of PV cells at the sub-module level to improve energy capture in the event of shading or mismatch. The converters operate in a parallel-ladder architecture, enforcing voltage ratios among strings of cells at terminals normally connected to bypass diodes. The balancing function extends from the sub-module level to the entire series string through a dual-core cable and connector. The parallel configuration allows converters to handle only mismatch power and turn off if there is no mismatch in the array. Measurement results demonstrate insertion loss below 0.1% and effective conversion efficiency above 99% for short-circuit current mismatch gradients up to 40%. The circuit implementation eliminates large power magnetic components, achieving a vertical footprint less than 6 mm. The merits of a resonant topology are compared to a switched-capacitor topology.

Solid-State Transformer Architecture Using AC–AC Dual-Active-Bridge Converter

Abstract: Modern development of semiconductor power-switching devices has promoted the use of power electronic converters as power transformers at the distribution level. This paper presents an ac–ac dual-active-bridge (DAB) converter for a solid-state transformer. The proposed converter topology consists of two active H-bridges and one high-frequency transformer. Four-quadrant switch cells are used to allow bidirectional power flow. Because power is controlled by the phase shift between two bridges, output voltage can be regulated when input voltage changes. This paper analyzes the steady-state operation and the range of zero-voltage switching. It develops a switch commutation scheme for the ac–ac DAB converters. Experimental results from a scaled-down prototype are provided to verify the theoretical analysis.

Sliding mode control of DC/DC converters

Abstract: Sliding mode control algorithms for buck and boost power converters are surveyed in the paper. Current and voltage controls are demonstrated for the both cases. It is shown, that direct voltage control for a boost converter results in unstable zero dynamics. Chattering suppression based on harmonic cancellation principle along with switching frequency control is demonstrated.

Multiobjective Switching State Selector for Finite-States Model Predictive Control Based on Fuzzy Decision Making in a Matrix Converter

Abstract: Finite-states model predictive control is a rising alternative in the control of power converters and drives. Successful application to different topologies and applications such as two-level voltage source inverters, neutral-point-clamped and cascaded H-bridge inverters, and matrix converters has shown its potential in power converters. However, when multiple control objectives are desired, weighting factors are required to appropriately select the switching states. The selection of these factors is a time-consuming and complex task. In this work, the standard selection stage is replaced by a fuzzy decision-making strategy, considering, as a case study, the control of both load and supply currents in the direct matrix converter (DMC). As a result, weighting-factor selection is avoided, and a simple selection scheme is obtained for this application. In addition, a more natural design approach to the state selection is opened for other applications. Simulation and experimental results are presented to validate the approach in an experimental DMC prototype.

Selective Harmonic Mitigation Technique for Cascaded H-Bridge Converters With Nonequal DC Link Voltages

Abstract: Multilevel converters have received increased interest recently as a result of their ability to generate high quality output waveforms with a low switching frequency. This makes them very attractive for high-power applications. A cascaded H-bridge converter (CHB) is a multilevel topology which is formed from the series connection of H-bridge cells. Optimized pulse width modulation techniques such as selective harmonic elimination or selective harmonic mitigation (SHM-PWM) are capable of preprogramming the harmonic profile of the output waveform over a range of modulation indices. Such modulation methods may, however, not perform optimally if the dc links of the CHB are not balanced. This paper presents a new SHM-PWM control strategy which is capable of meeting grid codes even under nonequal dc link voltages. The method is based on the interpolation of different sets of angles obtained for specific situations of imbalance. Both simulation and experimental results are presented to validate the proposed control method.

Reliability Calculation of Multilevel Converters: Theory and Applications

Abstract: Multilevel converters have many power devices and drivers. Thus, a direct reliability calculation based only on the first failure occurrence on one of the components clearly leads them to be devalued compared to two-level converters. However, taking into account that symmetrical multilevel converters such as the X-level active neutral point clamped (ANPC) family are based on imbricated and/or stacked switching cells on the one hand, with an additional center tap at the dc bus in three-phase operation on the other hand, several redundancies clearly appear which can be managed to increase the global reliability. For the first time, a general and theoretical methodology used to calculate reliability laws and failure rates and applied to compare two-, three-, and five-level topologies is proposed. Results show that the fault handling of three- and five-level three-phase topologies permits a great increase in reliability over a “relatively” short time duration, in addition to other benefits.

Fault Diagnosis of DC-Link Capacitors in Three-Phase AC/DC PWM Converters by Online Estimation of Equivalent Series Resistance

Abstract: In this paper, a novel scheme for the estimation of the equivalent series resistance (ESR) of the dc-link electrolytic capacitor in three-phase ac/dc pulsewidth-modulation converters is proposed for condition monitoring. First, a controlled ac current component is injected into the input. Then, it induces ac voltage ripples on the dc output. By manipulating these ac voltage and current components with digital filters, the value of the ESR can be calculated, where the recursive least squares algorithm is used for reliable estimation results. In addition, the value of the ESR is corrected by considering the temperature effect, for which a simple temperature-sensing circuit has been designed. The simulation and experimental results show that the estimation error of the ESR is within a reasonable range, thereby enabling the determination of the appropriate time for the replacement of the capacitor.

Open- and Short-Circuit Switch Fault Diagnosis for Nonisolated DC–DC Converters Using Field Programmable Gate Array

Abstract: Fault detection (FD) in power electronic converters is necessary in embedded and safety critical applications to prevent further damage. Fast FD is a mandatory step in order to make a suitable response to a fault in one of the semiconductor devices. The aim of this study is to present a fast yet robust method for fault diagnosis in nonisolated dc–dc converters. FD is based on time and current criteria which observe the slope of the inductor current over the time. It is realized by using a hybrid structure via coordinated operation of two FD subsystems that work in parallel. No additional sensors, which increase system cost and reduce reliability, are required for this detection method. For validation, computer simulations are first carried out. The proposed detection scheme is validated on a boost converter. Effects of input disturbances and the closed-loop control are also considered. In the experimental setup, a field programmable gate array digital target is used for the implementation of the proposed method, to perform a very fast switch FD. Results show that, with the presented method, FD is robust and can be done in a few microseconds.

Fault-Tolerant Strategy for a Photovoltaic DC--DC Converter

Abstract: The photovoltaic (PV) technology has a small impact on the environment and is suitable for a wide range of applications. The main barrier for a more extensive implementation has been the reliability, mainly related to the power converters. According to this consideration, this paper presents an open-circuit fault diagnosis and fault-tolerant scheme for a three-level boost converter in a PV power system using batteries as storage devices. The fault diagnostic method takes advantage only of the control variables used for maximum power point tracking and output dc-link capacitor voltage balance. The fault-tolerant strategy requires only a few components added to the original three-level boost converter, so that, under an open-circuit power switch fault, it can be partly reconfigured into a two-level boost converter ensuring battery energy supply. Experimental results verify the proposed fault diagnostic method and reconfiguration for fault-tolerant operation.

Improved Voltage-Vector Sequences on Dead-Beat Predictive Direct Power Control of Reversible Three-Phase Grid-Connected Voltage-Source Converters

Abstract: This paper presents a dead-beat predictive direct power control (DPC) strategy and its improved voltage-vector sequences for reversible three-phase grid-connected voltage-source converters (VSCs). The instantaneous variation rates of active and reactive powers, by applying each converter voltage vector in 12 different sectors, are deduced and analyzed. Based on the power variation rates, it is found that the values of the predicted duration times for the two conventional active converter voltage vectors are less than zero when the grid-connected VSC operates as either a rectifier or an inverter. In order to solve this issue, two new alternative vector sequences are proposed and compared. Experimental results on a 1.5 kW reversible grid-connected VSC system are presented to validate the feasibility of the proposed voltage-vector sequences on the dead-beat predictive DPC strategy.

Hybrid Voltage and Current Control Approach for DG-Grid Interfacing Converters With LCL filters

Abstract: This paper presents a hybrid voltage and current control method to improve the performance of interfacing converters in distributed generation (DG) units. In general, current-controlled methods have been widely adopted in grid-connected converters nowadays. Nevertheless, in an islanded system, the voltage control of DG units is desired to provide direct voltage support to the loads. Due to the absence of closed-loop line current controller, the voltage control scheme can hardly regulate the DG unit's line current harmonics. Furthermore, if not addressed properly, the transfer between the grid-connected operation and autonomous islanding operation will introduce nontrivial transient currents. To overcome the drawbacks of voltage- and current-controlled DG units, this paper develops a hybrid voltage and current control method (HCM). The proposed method allows the coordinated closed-loop control of the DG unit fundamental voltage and line harmonic currents. With the HCM, local harmonic loads of the DG unit can even be compensated without using harmonic current extraction. In addition, the HCM guarantees smooth transition during the grid-connected/islanding operation mode transfer. Simulated and experimental results are provided to verify the feasibility of the proposed approach.

Adaptive Active Capacitor Converter for Improving Stability of Cascaded DC Power Supply System

Abstract: Connecting converters in cascade is a basic configuration of dc distributed power systems (DPS). The impedance interaction between individually designed converters may make the cascaded system unstable. The previous presented approaches of stabilizing the cascaded systems need to modify the source and/or load converter's internal structure such as the topology and control circuit that are contradictory to the modularization characteristic of dc DPS. In this paper, an adaptive active capacitor converter (AACC) is introduced to stabilize the cascaded system. The AACC is connected in parallel with the cascaded system's intermediate bus and only needs to detect the bus voltage without any change of the existing subsystems. Hence, it can be designed as a standard module for dc DPS. The AACC serves as an equivalent bus capacitor to reduce the output impedance of the source converter, thus avoiding the intersection with the load converter's input impedance, and as a result, the cascaded system becomes stable. The equivalent bus capacitor emulated by the AACC is adaptive according to the output power of the cascaded system, and thus, the power loss of AACC is minimized and the dynamic response of the system is better than that of the system using a passive capacitor. Furthermore, since no electrolytic capacitor is needed in the AACC, the cascaded system's lifetime is prolonged. The operation principle, control, and design consideration of the AACC are discussed in this paper, and a 480 W cascaded system comprising two phase-shifted full-bridge converters has been built and evaluated. The experimental results verify the validity of the proposed AACC.

Intelligent Model-Based Control of a Standalone Photovoltaic/Fuel Cell Power Plant With Supercapacitor Energy Storage

Abstract: A renewable energy hybrid power plant, fed by photovoltaic (PV) and fuel cell (FC) sources with a supercapacitor (SC) storage device and suitable for distributed generation applications, is proposed herein. The PV is used as the primary source; the FC acts as a backup, feeding only the insufficiency power (steady-state) from the PV; and the SC functions as an auxiliary source and a short-term storage system for supplying the deficiency power (transient and steady-state) from the PV and the FC. For high-power applications and optimization in power converters, four-phase parallel converters are implemented for the FC converter, the PV converter, and the SC converter, respectively. A mathematical model (reduced-order model) of the FC, PV, and SC converters is described for the control of the power plant. Using the intelligent fuzzy logic controller based on the flatness property for dc grid voltage regulation, we propose a simple solution to the fast response and stabilization problems in the power system. This is the key innovative contribution of this research paper. The prototype small-scale power plant implemented was composed of a PEMFC system (1.2 kW, 46 A), a PV array (0.8 kW), and an SC module (100 F, 32 V). Experimental results validate the excellent control algorithm during load cycles.

Photovoltaic Generator as an Input Source for Power Electronic Converters

Abstract: A photovoltaic (PV) generator is internally a power-limited nonlinear current source having both constant-current- and constant-voltage-like properties depending on the operating point. This paper investigates the dynamic properties of a PV generator and demonstrates that it has a profound effect on the operation of the interfacing converter. The most important properties an input source should have in order to emulate a real PV generator are defined. These properties are important, since a power electronic substitute is often used in the validation process instead of a real PV generator. This paper also qualifies two commercial solar array simulators as an example in terms of the defined properties. Investigations are based on extensive practical measurements of real PV generators and the two commercial solar array simulators interfaced with dc-dc as well as three- and single-phase dc-ac converters.

Average-Current-Based Conduction Losses Model of Switched Capacitor Converters

Abstract: A generic modeling methodology that analyzes the losses in switched capacitor converters (SCC) operating in open loop was developed and verified by simulation and experiments. The proposed analytical approach is unified, covering both hard- and soft-SCC topologies that include active switches and/or diodes. An important feature of the proposed model is that it expresses the losses as a function of the average currents passing through each flying capacitor during each switching phase. Since these currents are linearly proportional to the output current, the model is also applicable to SCC with multiple capacitors if it can be assumed that each of the subcircuits of the modeled SCC can be described or approximated by a first-order system. The proposed model can be used to assess the effect of the operational conditions of the SCC, such as switching frequency and duty cycle, on the expected losses. As such, the model can help in the optimization of SCC systems and their control to achieve high efficiency and the desired regulations.

A Comparative Assessment of Model Predictive Current Control and Space Vector Modulation in a Direct Matrix Converter

Abstract: Matrix converters (MCs) are a very attractive alternative to conventional back-to-back converters with dc links. In this paper, a performance comparison between the well-established space vector modulation (SVM) technique and model predictive control (MPC) is presented for the current regulation in a direct MC. Both methods are analyzed and contrasted through simulation and experimental results. In order to establish their strengths and weaknesses, the assessment is made by measuring and comparing output and input currents and voltages with the same voltage source and load current conditions. Our results show that MPC is simpler than SVM from a conceptual point of view and provides better source current behavior, particularly with a distorted source voltage.

Capacitor Voltage Regulation in Single-DC-Source Cascaded H-Bridge Multilevel Converters Using Phase-Shift Modulation

Abstract: Cascaded H-bridge multilevel power electronic converters generally require several dc sources. An alternative option is to replace all the separate dc sources feeding the H-bridge cells with capacitors, leaving only one H-bridge cell with a real dc voltage source. This will yield a cost-effective converter. However, the required capacitor voltage balancing is challenging. In this paper, using the phase-shift modulation approach, a new control method for cascaded H-bridge multilevel converters fed with only one independent dc source is presented. The proposed method has a wide voltage regulation range for the replacement capacitors in the H-bridge cells. Experimental and simulation results support the proposed control method.

Survey and Benchmark of Fully Integrated Switching Power Converters: Switched-Capacitor Versus Inductive Approach

Abstract: This paper surveys and discusses the state-of-the-art of integrated switched-capacitor and inductive power converters. After introducing applications that drive the need for integrated switching power converters, implementation issues to be addressed for integrated switched-capacitor and inductive converters are given, as well as design examples. At the end of this paper, a comprehensive set of integrated power converters are compared in terms of the main specifications and performance metrics, thereby allowing a categorization and providing application-oriented design guidelines.

Cascaded Multilevel Converters: Optimal Asymmetries and Floating Capacitor Control

Abstract: Cascaded multilevel (CM) converter is a series connection of several inverters that together generate multiple voltage levels with controllable frequency, phase, and amplitude. Its main advantages are high power, reliability, and power quality. However, it has considerable drawbacks such as high number of components, many isolated power sources, decreasing voltage quality with the modulation index, and regeneration in some series inverters at specific modulation indexes, even when the machine is motoring. The authors propose to improve any CM topology through two solutions: use optimal voltage asymmetries (ratios), higher than conventional ones; replace the voltage sources by floating capacitors balanced with a new control (PI controller) and/or a high-frequency link. This paper presents theoretical analysis and experimental results of CM converters with increased voltage-quality (levels), some of them keeping this high quality and avoiding regeneration in motor mode at any motor operation point, using the proposed voltage asymmetries and simplifying or eliminating some voltage sources. Experimental results show a reduction of components, an improved voltage quality, and a satisfactory behavior in stationary and dynamic operation.

Multilevel SVPWM With DC-Link Capacitor Voltage Balancing Control for Diode-Clamped Multilevel Converter Based STATCOM

Abstract: In this paper, a space vector pulsewidth modulation (PWM) (SVPWM) algorithm is proposed, which is in α'β' frame with dc-link capacitor voltage equalization for diode-clamped multilevel converters (DCMCs). The α'β' frame is a coordinate system similar to the αβ frame. In this frame, some original complex calculations are substituted by integer additions, integer subtractions, truncations, etc. It brings the time and area efficiency to fixed-point digital realization, particularly for the application in a field-programmable gate array. Meanwhile, a minimum energy property of multiple dc-link capacitors is applied as the basic principle for voltage equalization based on a capacitor current prediction algorithm. By evaluating the redundant vectors in each pulse dwelling period, the balancing algorithm chooses an optimal vector, generates the optimal PWM signals, and sustains the voltage stability. After that, an arbitrary multilevel SVPWM intellectual property core is designed and analyzed in the α'β' frame. At the end of this paper, a five-level DCMC-based static synchronous compensator is built and tested. The experimental results verify the balancing algorithm and the system steady-state and dynamic performances.

Analysis and Control of Modular Multilevel Converters Under Unbalanced Conditions

Abstract: This paper investigates the contents of submodule voltage ripples, circulating currents, and internal converter voltage in modular multilevel converters (MMCs) theoretically. The operation of MMCs is studied under asymmetry of the upper and lower arm, as well as the unbalanced ac system. In three-phase MMCs, the analysis shows that the second harmonic circulating currents will be asymmetric under an unbalanced ac system and can be decomposed into positive-, negative- and zero-sequence parts. The positive- and negative-sequence components affect neither the ac side nor the dc side of MMCs while the zero-sequence components will flow into the dc side, aggravating the power fluctuations of the dc side. In order to solve this problem, a new controller based on the instantaneous power theory and proportional-resonant scheme is designed. Simulations with a detailed switching model on the PSCAD/EMTDC platform verify the theoretical analysis, and demonstrate that the proposed controller eliminates the active power fluctuations and suppresses the harmonic circulating currents as well.

Parallel Operation of Full Power Converters in Permanent-Magnet Direct-Drive Wind Power Generation System

Abstract: Parallel operation is an effective way to improve the capacity of full power converter in permanent-magnet direct-drive wind power generation system. But it causes the zero-sequence circulating-current (ZSCC), which brings current discrepancy, current waveform distortion, power losses, and electromagnetic interference (EMI), etc. The paper proposes a new topology of full power converters which are composed of n full power converters. The n converters have the same structures and are in parallel with each other. Besides, the average models of the system are analyzed and the fundamental mechanism of ZSCC generation is given. Based on the above analysis, the control strategy of the system is designed. The simulation and experiment results of two parallel full power converters show the feasibility of the proposed theory and control scheme.

High-Efficiency Hybrid Full-Bridge–Half-Bridge Converter With Shared ZVS Lagging Leg and Dual Outputs in Series

Abstract: A novel soft-switching hybrid converter combining the phase-shift full-bridge (FB) and half-bridge (HB) LLC resonant converters' configuration with shared zero-voltage switching (ZVS) lagging leg is proposed to ensure the switches in the lagging leg operating at fully ZVS condition. The dual outputs of the proposed hybrid FB-HB converter are connected in series and the whole dc-output voltage can be regulated by the PWM phase-shift control within the desired voltage range. A resonant circuit is used in the secondary side of the FB converter to reset the primary current during the freewheeling period, as well as to transfer more input energy and clamp secondary rectifier voltage. The proposed converter is attractive for hybrid electric vehicle/electric vehicle on-board charger applications. The principle of operation, the validity, and performance are illustrated and verified on a 3.7-kW experimental circuit. Experimental results show that the proposed converter can get good efficiency curves at different operation points, and the maximum efficiency is 98.30%.