Converter For Electric Vehicles Research Articles

A ZVS-ZCS quadratic boost converter to utilize the energy of PV irrigation system for electric vehicle charging application

Finding diverse applications of installed PV based power generating unit is necessary for optimal utilization of energy produced by these units over a period of time. This paper proposes a high gain boost converter that can be used as a DC source for electric vehicle charging application in existing PV based solar pump set-up. The proposed DC-DC converter uses two-stage boosting to achieve a high voltage gain in the form of quadratic quadrupled boost factor. Low turns ratio in coupled inductor reduces the loss components of magnetic part largely. Another advantage of the proposed converter is its operation at lower duty ratio (~0.5) to achieve the desired voltage gain for photovoltaic application. Further, leakage inductance is effectively utilized to achieve ZCS of solid-state devices in conjunction with magnetizing inductance, which provides ZVS for the efficient operation of converter. To analyze the performance of proposed converter for electric vehicle charging application, simulations were carried out using PSIM/MATLAB software and results were validated using experiments conducted on a 250 W hardware prototype developed in the laboratory. A boost factor of 7.8 is achieved at a turn’s ratio of 1.9 for ~35% duty ratio of main switch. The maximum efficiency of ~93% is measured for designed converter.

Soft-Switching Power Electronics Technology for Electric Vehicles: A Technology Review

Power electronic converters for electric vehicles (EVs) have been the subject of great interest over the last several decades. This article presents a thorough review of different EV power electronic converters on which the authors have worked for more than one decade. The readers will find this review interesting to design current products and to devise/invent new converters for emerging applications in EV.

An Integrated Converter With Reduced Components for Electric Vehicles Utilizing Solar and Grid Power Sources

A novel integrated converter for electric vehicles (EVs) is proposed in this article. For battery-charging operation, the proposed converter system enables a complementary deployment of the utility grid and a solar photovoltaic (PV) system. Since both sources (acting one at a time) utilize the same converter, the developed charging system, therefore, has a smaller number of components. In addition, an inductor voltage detection (IVD) technique has been incorporated to correct the power factor (PF) in continuous conduction mode (CCM), which eliminates the need for a current sensor for PF correction (PFC). The proposed system operates for all the modes required for an EV, e.g., charging, propulsion (PRN), and regenerative braking (RBG). In charging mode (with either grid or solar PV), the proposed system operates as an isolated secondary ended primary inductance converter (SEPIC) converter. In PRN and RBG modes, it operates as a boost converter and a buck converter, respectively. Details of all these modes are described in the article, along with the design of the components. In addition, results of simulation and experimental studies are presented for a 1-kW setup based on the proposed configuration. A comparison with other topologies shows the technoeconomic competence of the proposed system.

A Reconfigurable On-Board Power Converter for Electric Vehicle With Reduced Switch Count

This paper proposes a compact reconfigurable on-board power converter for low voltage electric vehicle. The proposed converter serves the purpose of a battery charger as well as a 3-phase voltage source inverter (VSI) to drive the traction motor. The 3-phase VSI is the backbone of this converter that can be either reconfigured to a propulsion unit or to a battery charger by adding few more power electronics components. During charging mode, the topology is reconfigured to form a front-end boost power factor correction rectifier which is cascaded by a DC-DC converter through a DC link. The same power stage is reconfigured to operate as a 3-phase VSI to drive the traction motor during propulsion mode. Thus, it reduces the switch count by eliminating the requirement of a separate inverter stage. Simultaneously the weight, volume, and cost of the overall system are reduced. Unified control technique is implemented which is capable to achieve near-unity power factor operation of front-end boost rectifier as well as optimal battery charging without sensing the DC link voltage. This control scheme implements a single control loop for both stages by eliminating the need of two separate control loop for each stage of the charger. A 470 W scaled-down prototype is developed and its performance is validated with Constant Current-Constant Voltage charging of a 24 V, 30Ah battery pack in charging mode and with a 400W BLDC motor in propulsion mode.

A Multifunctional Solar PV and Grid Based On-Board Converter for Electric Vehicles

This work deals with the development of a multifunctional power electronic converter (PEC) utilizing dual power sources (grid and solar photovoltaic (PV)) for charging phenomenon of plug-in electric vehicles (PEVs). The developed configuration accomplished all modes of vehicles (charging, propulsion (PP) and regenerative braking (RB)). In standstill condition of vehicle, the battery is either charged by grid or simultaneously by both grid and solar PV system. In running mode, the battery can also be charged through RB operation by utilizing kinetic energy of vehicle wheels. The proposed converter operates as an isolated SEPIC in plug-in charging (PIC) mode and as a non-isolated SEPIC in solar PV charging mode. Further, in PP and RB modes, operation of the proposed PEC as a conventional boost converter and conventional buck converter, respectively. Both the simulation and experimental validations for all modes of the proposed converter have been presented.

A Framework of Multilayer Multiphase Interleaved Converter for Electric Vehicle Based on Graph Theory

Lithium-ion batteries play an important role in large-scale energy storage systems. However, the power inconsistency of the battery packs restricts the developments of modern technologies in energy storage area. The motivation of the present study is to serve the growing needs of the energy balance for lithium-ion battery packs. The present study proposes a flexible multiphase interleaved converter for the energy equalization of a lithium battery pack with series configuration. Moreover, the graph theory is applied to the analysis of equalization circuits. It is intended to establish a unified standard for the comparison. The parameter of average efficiency is considered as an important indicator to evaluate the characteristics of the equilibrium system. The proposed method is verified by constructing a lithium-ion battery pack with the equalization circuit. It is observed that the proposed multiphase interleaved converter has flexible characteristics, while it has low energy loss compared with the conventional methods. It is found that the proposed method simplifies the complex equalization circuits into graphs and facilitates the comparison of the average efficiency of the system. It is concluded that this method is a feasible and powerful method for evaluating the battery equalization circuit. This approach can be applied for solving complex problems in other engineering applications.

Emulation of Loss Free Resistor for Single-Stage Three-Phase PFC Converter in Electric Vehicle Charging Application

In this article, the modular three-phase ac-dc converter using single-phase isolated Ćuk rectifier modules for charging of electric vehicles is discussed. The converters are designed and analyzed for the continuous conduction mode (CCM). This article is based on a new concept of adaptive sliding-mode-based loss-free resistor (ASLFR). ASLFR is a control scheme, which allows dual aim of power factor correction along with tight voltage regulation; hence, the adopted topology serves as a fitting single-stage solution for balanced three-phase systems. Complete theory is developed for the application, and the effectiveness of the scheme is well-established. Various studies to confirm the robustness of the system to any load and line variation are carried out. Moreover, a qualitative analysis is also made to show the expediency of the proposed ASLFR. Simulation as well as experimental studies are claimed theoretically.

Multiphase Interleaved Bidirectional DC-DC Converter for Electric Vehicles and Smart Grid Applications

This paper deals with the design and the control of multiphase interleaved bidirectional DC-DC converter. This converter is used for Electric Vehicle (EV) applications to convert and increase energy storage system voltage from low side voltage to high side voltage, which is necessary to feed the inverter used to drive the traction motor. The proposed converter can be also used to connect the energy storage system to the smart grid. To increase the performance of high side voltage and to have equal sharing of the load current in each converter module a fuzzy sliding mode control is proposed. The control method is tested by simulation of 4 interleaved bidirectional DC-DC converter associated with the three-phase inverter coupled with a 3 phase induction motor. The simulation results exposed the robustness of the proposed control method under some disturbances. Â

Bidirectional Three-Level Stacked Neutral-Point-Clamped Converter for Electric Vehicle Charging Stations

Electric vehicles (EVs) powered by batteries and other energy storage devices (ESDs), e.g., ultracapacitors, are expected to play an important role in the development of a more sustainable future. In this context, charging stations (CSs) are supposed to become the main sources of energy for charging the batteries, being strongly dependent on power electronic converters. This paper analyzes a bidirectional single-phase, three-level stacked neutral-point-clamped (3L-SNPC) converter for CS applications, which may behave as a rectifier or an inverter depending on the power flow direction. Besides, the derived analysis can be easily extended to the development of a three-phase version. Considering that the CS is capable of integrating the utility grid and renewable energy sources, it is possible to absorb or inject energy into the ac grid with high power factor and reduced harmonic content of the current. The main advantages of the bidirectional topology are the existence of a three-level voltage waveform across each leg and the neutral point, while filtering requirements are reduced when compared with typical two-level structures used in EV CSs; the voltage stresses on all semiconductors are equal to half of the total dc-link voltage; power factor is nearly unity in any operation mode; and the voltages across the dc-link capacitors are balanced. The thorough design of the power and control stages is presented, as well as experimental results from a laboratory prototype are discussed in detail.

An overview of electric vehicle converter configurations, control methods and charging techniques

The prospects of Electric Vehicles (EVs) have gained momentum due to the weakening of fossil fuels and the emergence of global warming issues. Moreover, highly energy-efficient vehicles have grown in stature due to the rapid progress made by power electronic equipment. It is a fact that the transportation sector consumes a sizable chunk of energy throughout the world. EVs are the solution for this problem as they reduce the radiation of greenhouse gases. Since one third of the EV cost is dependent on its battery, the batteries and the pricing structure have undergone several experiments. The causes and the availability of the energy sources, alternative energy sources, contemporary control methods for formulating policies of energy management, configurations of converting DC-DC in EV applications and the methods of charging EV in a smart environment are exhaustively reviewed in the present study. The study evaluates the challenges and benefits of implementing electric vehicle technology. The utility grid encompasses several alternative energy resources due to the speedy development of EV. Thus, managing and meeting the increasing demand for alternative energy resources could be achieved by using smart grid control.

An overview of electric vehicle converter configurations, control methods and charging techniques

The prospects of Electric Vehicles (EVs) have gained momentum due to the weakening of fossil fuels and the emergence of global warming issues. Moreover, highly energy-efficient vehicles have grown in stature due to the rapid progress made by power electronic equipment. It is a fact that the transportation sector consumes a sizable chunk of energy throughout the world. EVs are the solution for this problem as they reduce the radiation of greenhouse gases. Since one third of the EV cost is dependent on its battery, the batteries and the pricing structure have undergone several experiments. The causes and the availability of the energy sources, alternative energy sources, contemporary control methods for formulating policies of energy management, configurations of converting DC-DC in EV applications and the methods of charging EV in a smart environment are exhaustively reviewed in the present study. The study evaluates the challenges and benefits of implementing electric vehicle technology. The utility grid encompasses several alternative energy resources due to the speedy development of EV. Thus, managing and meeting the increasing demand for alternative energy resources could be achieved by using smart grid control.

Design and Analysis of Higher Efficiency Non isolated DC-DC Converter for Electric Vehicles

The design and analysis of higher efficiency non isolated DC-DC converter for Electric Vehicles is presented. A Battery Charging System (BCS) plays a key role in achieving fast charging and higher efficiency. The BCS integrates acascaded DC-DC converter and a bidirectional PWM converter. In order to achieve more reliability and stiff voltage, aCascaded buckboost converter which is partitioned with the help of a capacitor is integratedand to achieve higher efficiency with less number of switches, a bidirectional PWM converter used There are various PWM techniques, among them hysteresis and sinusoidal pwm technique are used. The output voltage obtained after both the operations (boost and buck) is given to the battery or load. Simulation is done in MATLAB and the results are analyzed with PI controller and without PI controller in this paper.

Implementation of Dual-Circuit System for Additional Power Supply Based on Photovoltaic Converters for Electric Vehicles

The article presents a process of designing the photovoltaic (PHV) converters system for an electric vehicle, shows the scheme of photovoltaic converters usage, the results of electric vehicle motion modeling with photovoltaic converters, and the results of road tests of an electric vehicle with an additional power source based on photovoltaic converters. The photovoltaic converters system and low-voltage system of an electric vehicle have a shared low-voltage battery, which allows the implementation of two schemes of electric vehicle power supply. Initially, the aggregate base was selected, then, taking into account the efficiency of each device included in the design of the new electric vehicle, mathematical modeling was carried out and showed good efficiency results of the photovoltaic converters system. Then, the prototype was manufactured and tested. The aggregate base included the battery of photovoltaic converters assembled in a certain way on the vehicle roof, the MPPT (maximum power point tracking) controller, the buffer storage device in the form of a 12 V battery, and the DC (direct current) converter that allows transmitting electricity from the buffer battery to the high-voltage system. Modeling of the electric vehicle motion considered typical operating modes, including energy costs for the operation of assistant systems of the electric vehicle, as well as including the consumption of low-voltage components. The tests were carried out according to the NEDC (New European Driving Cycle). As a result, implementation of photovoltaic converters with 21% efficiency allowed for the power reserve of the electric vehicle to be increased by up to 9%.

Design of Multi-Input Bidirectional DC to DC Converter for Electric Vehicles with Regeneration Capability

A multi-input bidirectional dc to dc converter which can be implemented for electric vehicles is discussed in this paper. The importance of the converter depends on the phenomenon of backing up of regenerated power during braking. Three energy storage systems feed a common DC bus that interfaces the bidirectional DC/DC converter. Lack of energy supply to the electric vehicles due to less charging stations can be overcome by proposed converter. Any one of the energy storage system will be active throughout the operation of the vehicle and that the DC bus is continuously fed by a constant DC power. Pulse width modulation scheme is used to convert the available supply in the battery toe appropriate supply of the DC bus. The converter is tested by connecting a brushless DC motor to the output and the performance is analyzed with three modes of power transfer. The converter is designed in MATLAB/SIMULINK tool and the performance characteristics are discussed.

Gate Drivers for High-Frequency Application of Silicon-Carbide MOSFETs: Design considerations for faster growth of LV and MV applications

With the advent of wide-bandgap (WBG) semiconductor devices, silicon-carbide (SiC)-based MOSFETs for high voltage and current serve as a viable replacement for conventional Si-based IGBTs [1], [2]. SiC-based MOSFETs combine the advantages of both IGBTs and MOSFETs, have a low on-state resistance at a high-voltage rating (similar to IGBTs), and lower-switching losses than those of Si MOSFETs, thus making it closer to an ideal switch [3]. This makes it possible for SiC MOSFETs to process high power at high-switching frequencies without compromising the efficiency of the system [4]. Due to the inherent lower on-state specific resistance and faster switching speeds in SiC MOSFETs, it is also possible to develop and use medium-voltage (MV) power semiconductor devices greater than 6.5 kV without experiencing very high losses [5]. The SiC MOSFET design and development can be divided into two broad categories: low-voltage (LV)-blocking (l3.3-kV) and MV-blocking (g3.3-kV) SiC MOSFETs [6]. Although MV SiC MOSFETs can enable niche applications, there is widespread use of LV-blocking power devices in various applications such as renewable energy, drives for electrical machines, power converters for electric vehicles, and so on, whereas SiC MOSFETs can offer a multitude of advantages over Si IGBTs [7], [8].

FPGA based Hybrid Resonant Switching DC/DC converter for Electric Vehicles

A hybrid switching DC-DC converter for Hybrid Electric Vehicle with reduced on state conduction losses, voltage stress and switching losses of the power semiconductor devices is presented in this paper. Zero current switching and zero voltage switching is achieved for the leading and lagging legs of the inverter by using bipolar switching method. This reduces the circulatory losses in the transformer primary. Additionally it aids in exploiting the leakage inductance of the transformer to resonate with the output capacitor. Consequently this reduces the components count and the converter size. This results in efficient energy transfer as the inductive energy and capacitive energy acquired by the output inductor and resonant capacitor are simultaneously transferred to the load during the freewheeling interval. This boosts the converter efficiency when compared to the conventional converter. During active intervals, inductor is charged and the increased capacitor voltage is offered to the load. The bipolar circuit voltage is clamped during the freewheeling interval and reduces the peak voltage overshoots that crop up during the diode reverse bias period. Simulation for the DC-DC converter is rendered with PSpice software and the experimental results shows the desired output is achieved with reduced losses under variable load conditions.

Control of a Multiphase Buck Converter, Based on Sliding Mode and Disturbance Estimation, Capable of Linear Large Signal Operation

Power-hardware-in-the-loop systems enable testing of power converters for electric vehicles (EV) without the use of real physical components. Battery emulation is one example of such a system, demanding the use of bidirectional power flow, a wide output voltage range and high current swings. A multiphase synchronous DC-DC converter is appropriate to handle all of these requirements. The control of the multiphase converter needs to make sure that the current is shared equally between phases. It is preferred that the closed-loop dynamic model is linear in a wide range of output currents and voltages, where parameter variations, control signal limits, dead time effects, and so on, are compensated for. In the case presented in this paper, a cascade control structure was used with inner sliding mode control for phase currents. For the outer voltage loop, a proportional controller with output current feedforward compensation was used. Disturbance observers were used in current loops and in the voltage loop to compensate mismatches between the model and the real circuit. The tuning rules are proposed for all loops and observers, to simplify the design and assure operation without saturation of control signals, that is, duty cycle and inductor current reference. By using the proposed control algorithms and tuning rules, a linear reduced order system model was devised, which is valid for the entire operational range of the converter. The operation was verified on a prototype 4-phase synchronous DC-DC converter.

A comprehensive Review on Bidirectional Traction Converter for Electric Vehicles

A comprehensive Review on Bidirectional Traction Converter for Electric Vehicles

A Novel Bidirectional T-Type Multilevel Inverter for Electric Vehicle Applications

This paper introduces a new configuration of bidirectional multilevel converter in electric vehicle (EV) applications. It has multilevel dc–dc converter with a dc link capacitor voltage balance feature. The multilevel dc–dc converter operates in a bidirectional manner, which is a fundamental requirement in EVs. Compared to the conventional configurations, the proposed one only implements two extra power switches and a capacitor to balance the voltage of the T-type multilevel inverter (MLI) capacitor over a complete drive cycle or at fault conditions. Therefore, no extra isolated sensor, control loops, and/or special switching pattern are required. Moreover, the proposed configuration due to the high-frequency cycle-by-cycle voltage balance between ${C_N}$ and ${C_P}$ , the bulky electrolytic capacitors used in T-type MLI, are replaced with more reliable longer life film capacitors. This will result in a size and weight reduction of the converter by 20%. This allows more real estate for the EV battery in the chassis’ space envelope to increase its capacity. The proposed configuration is tested and validated using a matlab /Simulink simulation model. A laboratory prototype of 1 kW is built to provide the proof of concept results as well.

Intelligent Control of Converter for Electric Vehicles Charging Station

Electric vehicles (EVs) are envisaged to be the future transportation medium, and demonstrate energy efficiency levels much higher than conventional gasoline or diesel-based vehicles. However, the sustainability of EVs is only justified if the electricity used to charge these EVs is availed from a sustainable source of energy and not from any fossil fuel or carbon generating source. In this paper, the challenges of the EV charging stations are discussed while highlighting the growing use of distributed generators in the modern electrical grid system. The benefits of the adoption of photovoltaic (PV) sources along with battery storage devices are studied. A multiport converter is proposed for integrating the PV, charging docks, and energy storage device (ESD) with the grid system. In order to control the bidirectional flow between the generating sources and the loads, an intelligent energy management system is proposed by adapting particle swarm optimization for efficient switching between the sources. The proposed system is simulated using MATLAB/Simulink environment, and the results depicted fast switching between the sources and less switching time without obstructing the fast charging to the EVs.