Summary This paper describes a quasi‐two‐switch buck‐boost power factor correction (PFC) converter for use in on‐board battery chargers to create a variable output voltage that is less than or greater than the peak input voltage. A two‐stage converter links the input grid power to the battery pack both in battery‐operated electric cars (BEVs) and plug‐in hybrid electric vehicles (PHEVs), with battery pack voltages ranging from 100 to 500 V depending on vehicle size and capacity. A universal charger that can manage such a wide range of battery pack voltages is appropriate for all vehicle designs. This requirement is met by supplying a changeable DC link voltage at the input of the DC/DC converter, which is a major obstacle in battery chargers when it comes to achieving universal output voltages. The major contribution of this research is the analysis and design of a dual‐control technique for a cascaded buck‐boost converter suited for a power factor correction (PFC) rectifier. The control loop is designed to allow a seamless transition from buck‐boost operation while putting less stress on the devices. The converter's power loss and small‐signal model are also investigated. From an economic standpoint, this concept allows the automobile industry to manufacture a single power converter, which is flexible and capable of charging numerous vehicle variants. Results have been verified both with a PSIM (11.0) simulation model and an experimental setup for a 1‐kW PFC converter suitable for universal input voltages of 85–265 Vrms and broad output voltages.

A novel method for controlling the output DC link voltage of a single-phase power factor correction (PFC) converter without using a DC voltage sensor for electric vehicle (EV) charging is proposed in this paper. The conventional boost PFC converter normally uses three expensive sensors, i.e., at the input voltage, the input current, and the output voltage. These sensors are used to regulate the power quality and maintain system stability. To reduce the cost and hardware complexity in the power converter, a DC voltage sensorless control using an estimator is proposed. This method utilizes the available input voltage and current signals to predict the output DC link voltage. This predicted output voltage contains an average DC component superimposed with a small ripple content at double the line frequency (2 f ). The proposed control method tracks the reference sinewave signal to maintain a high-power factor. The converter also exhibits very stable behavior under transient load variations. Simulated and experimental validation results obtained with a 1 kW prototype PFC converter are included.

A practical approach in modeling a capacitive wireless power transfer (CPT) system that utilizes an electrostatic field for the power transfer is presented in this article. The reduced capacitance model (RCM) is derived from the conventional six capacitance model (SCM) for the CPT system in view of the large charging area applications, such as electric vehicle charging. The effect of the same side and cross-coupling capacitances diminishes when the separation distance between the same side plate pair is large enough, and the reduced capacitance model (RCM) is obtained. A bipolar capacitive-link dispersion distance proposed in this article acts as an indicator to decide the use of RCM or SCM depending on the application. Furthermore, RCM attains unity voltage gain and load-independent operation at the designed single resonant frequency, unlike the SCM, where the influence of multiple resonant frequencies is predominant. An experimental validation is performed to determine the effectiveness of the RCM.

This paper proposes a high power factor correction (HPFC) converter using a GaN HeMT MOSFET for the onboard EV charging application. Power factor plays a decisive role in AC–DC conversion. Low power factor load draws high current from the main supply. To optimize the active power drawn from the supply mains, the system's power factor must be kept close to unity. It boosts the converter's effectiveness and reliability. The power stage implementation is based on small-signal modeling, and the state-space averaging is used to derive the power-level transfer function of the HPFC converter. With the assistance of the MATLAB SISO tool, a control strategy for the voltage and current loops is proposed to satisfy the design criteria. Finally, a 3.3 kW GaN-based HPFC converter experiment is performed for the input power factor greater than 0.99 for different power and also shows the current THD for different values of power factor.

This paper proposes the designing procedure for Inductor-Inductor-Capacitor (LLC) Resonant DC-DC Converter using GaN HeMT MOSFET for on-board battery charger used in Electric Vehicle application. Based on LLC Converter's features and characteristics, design specification is studied. By using Fundamental Harmonics Approximation model, Zero Voltage Switching (ZVS) on the primary side has been reported by operating in different operating regions. The control scheme for the proposed converter is discussed to regulated output voltage. Finally, the model is proposed and tested using MATLAB simulation to transform 400 V input voltage to an output voltage range of 64.8-86.4 V at 3.3 KW, taking all parameters into account step by step.

Conventional vehicles (CV) or internal combustion engine vehicles represent the majority of vehicles on the road and the high demand for petroleum is a major cause for concern. The shortage of petroleum is one of the most critical global issues and increasingly costly fuel is one of the most critical issues for CV users. The frequent charging opportunities will reduce the battery pack size and increase the life of batteries. The electric drive feeds electricity into the motor in required amounts and at variable frequencies, thereby indirectly controlling the motor's speed and torque. The electrified transport is safe, reliable, has lower environmental impact and convenient technology. The developments that will happen in the coming years will determine how significant the role of charging strategies in advancing the transportation electrification and the sustainability of autonomous e-mobility. Compensating networks, which are capacitor arrays, are made to resonate with coil inductance, thus forming a resonant inductive link.

In this article, phase disposition pulse width modulation based reduced switching state multipoint clamped (MPC)-five level unidirectional rectifier has been proposed. The converter has been modeled and modulated similar to conventional MPC structured converter topologies without additional clamping diodes and flying capacitors. Besides that, the proposed topology has minimum total blocking voltage, thereby reducing losses and improved efficiency. Moreover, it enhances the system reliability, minimizes the cost, and weight of the converter system. The principle of operation, mathematical formulation, and control implementation of the proposed topology has been presented in this article. A relative comparison with existing unidirectional topologies has also been addressed. Moreover, the validated experimental results of the proposed topology have been presented along with the prototype hardware setup.

In this study, an off-board multi-terminal dc charger with active input current shaping for level-3 electric vehicle (EV) charging applications is proposed. The configuration is based on reduced switching state multi-point clamped, three phase improved power factor converter and supplied by the standard ac grid. The topology has the advantage of reduced device count along with reduced maximum device stress. This will increase the speed of EV charging and enables the reduction of capital and maintenance costs of the charging facilities, enhancing further expansion of the eco-friendly transport. In addition, one of the key performance indicator, i.e. the fault ride-through capability, is investigated in the proposed topology under various unbalanced input conditions. Further, steady-state and transient performance of topology during load, as well as, dc-link voltage change is presented. Minimum distorted and balanced line currents are drawn from supply by implementing negative sequence elimination control algorithm. The validation of the proposed topology is verified with simulation and a down-scaled experimental setup.

Battery Technology is ramping up these days with enormous boost in electric vehicle (EV) and hybrid electric vehicle (HEV) industry. One of the promising and crucial in batteries is to provide safe and quick charging algorithms. An extension of constant temperature and constant voltage (CT-CV) charging technique is studied in this paper, with a battery under test (BUT) of chemistry type Nickel Manganese Cobalt (NMC) 18650 lithium-ion cell. The analysis of the charging time, and surface temperature rise along with the PID controller gains used is performed at ambient temperature of 20°C. The performance and surface temperature analysis during charging and also discharge can be seen in this paper. In addition, the experimental setup is explained in detail with emphasis on the implemented CTCV algorithm. Also, the CT-CV charging technique implemented is compared to the standard constant current and constant voltage (CC-CV). By the end, the experimental results on tests performed with NMC cell is presented.

In this work, a new multi-point clamped (MPC)- five level converter topology with reduced switching state (RSS) for front end power conversion applications (mainly direct connected wind energy conversion) is proposed. The converter can be modelled and modulated as similar to conventional MPC structured converter topologies without additional clamping diodes and flying capacitors. In addition, the proposed topology requires, minimum total blocking voltage, thereby, reducing losses and improved efficiency. To validate the performance, high scale simulation as well as downscale experimentation is carried out.

Two-switch converters (TSCs) are widely used and are more efficient at high-power levels with lower component stress than the single-switch topologies. These converters have flexible operations in both boost and buck modes and are applicable to on-board battery chargers in the power factor correction (PFC) converter stage. The intermediate output voltage at PFC can be greater or lesser than the peak of input voltage (variable dc-link voltage), resulting in higher switching losses across the boost switch. An auxiliary circuit proposed in this article comprises an active switch and a diode with a pair of resonant inductors and capacitors that are applied across the main switch to operate with loss-less switching. Though the conduction time of the proposed auxiliary circuit is small compared with the main converter operation but attains the main switch to turn-on with zero-voltage transition and turn-off with zero-current transition. In addition, the auxiliary switch involved in the converter operation is also subjected to SS. In addition, the proposed converter has no extra component stress and switching losses. With this, it can enhance the overall converter efficiency. The various operating modes involved in different time intervals are analyzed and presented in this article. Moreover, the design criteria of the auxiliary circuit and the main converter parameters are also discussed in this article. As a proof-of-concept, a hardware prototype of 1 kW is implemented with the proposed control structure, and the results are presented in this article. Maximum efficiency of 97.4% has been achieved from the implemented hardware prototype.

On-board battery chargers (OBCs) offer the feasibility of charging electric vehicles or plug-in hybrid electric vehicles with a standard household power supply. In this study, an OBC using two-mode topology (step-up or step-down) is presented. One of the main concern with two-mode topologies is the hard transitions of the converter operating from boost mode to buck mode or vice versa, which can deteriorate the performance of converter. This study provides smooth transitions between the modes and can have an output that could be more or less than the peak of input voltage. The detailed analysis of operating modes involved in the converter are analysed in the study. Moreover, the stress analysis on the components is also detailed in this study and the results are compared with existing two-mode converters. A simple dual-loop control structure with the proposed modulation technique eliminates the sub-harmonic oscillations and stabilizes the output voltage is also presented in the study. Experimental validation is performed for a 1.0 kW laboratory prototype and the results obtained are detailed in the study. This proposed converter topology can be applied as a single-stage OBC or as a power factor correction converter with variable DC link voltages in isolated two-stage OBC.

This paper presents a constant temperature and constant voltage (CT-CV) based charging technique applied to a Nickel Manganese Cobalt (NMC) 18650 and lithium-ion cells. Analysis and behavior of the cell at different ambient temperature have been investigated in this paper. Moreover, the experimental procedure details, including the implemented CT-CV algorithm for analyzing the charging of batteries are detailed. The proposed CT-CV charging is compared with existing constant current and constant current (CC-CV) under different ambient temperatures and charging current rates. Finally, experimental validations are performed on NCM batteries and the results are presented.

In this paper, a novel multi-input single-output DC-DC converter topology for achieving fixed output power for variable input sources is proposed. The proposed topology consists of conventional boost and buck converters. Effective energy management strategy is used to provide energy to the load, if one of the input sources fails to operate. The converter benefits from several advantages such as minimal operation modes, no limitation for switching duty cycle and fewer components for the size and cost of the converter. Simple control system is introduced by using voltage and current control. Simulation and experimental results are presented to validate the performance of the topology.

Existing charging techniques for lithium-ion batteries use a largely open-loop approach, where the charge profile is predecided based on a priori knowledge of cell parameters. There is a need for closed-loop charging techniques that use instantaneous cell voltage and/or temperature to modulate the charging current magnitude. This paper addresses this gap by proposing a constant-temperature constant-voltage (CT-CV) charging technique, considering cell temperature as a key degradation metric. The proposed CT-CV charging scheme employs a simple and easy-to-implement proportional-integral-derivative (PID) controller aided by a feed-forward term. The charging current is dynamically adjusted in response to the battery temperature, which indirectly reflects its aging and thermal environment. As per experimental results, the proposed method achieves 20% faster charging with the same total temperature rise as constant-current constant-voltage (CC-CV) technique. Alternatively, it causes 20% lower cell temperature rise for given total charge time. It can easily accommodate applications that demand even faster charging by simply raising the set temperature. This paper establishes the benefits of the proposed CT-CV charging at cell level and raises the possibility of extending it to the pack level by integrating it with battery management systems.

On-board chargers (OBCs) in electric transportation resolve the anxiety for frequent charging of the battery packs. This paper presents a single-phase nonisolated OBC for electric transportation using a two-switch topology. The main advantage of this OBC is that it can perform high input power quality over a wide output voltage conversion range. The presented two-switch converter is able to operate with an output voltage above and below the peak of input voltages. The analysis and various operating modes of converter and design considerations to achieve the wide output voltages are discussed in this paper. Moreover, small-signal analysis of the converter in various modes to aid for the design of the controller is also presented. A two-mode control scheme with average current-mode (ACM) control structure using PI controllers is shown in this paper with a feature of automatic mode selection. As a proof of concept, the experimental results from a 1-kW laboratory prototype with an output voltage range of 150-450 V are presented. A high input power factor of 0.99 and an efficiency of 96 have been achieved from the prototype.

On-board battery chargers resolve the anxiety of frequent charging of the battery operated electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs) with an available household input supply. Conventionally, a two-stage converter connects the input grid supply to the battery pack whose voltage typically differs for various range of vehicle architectures. This paper mainly focuses on analysis and operation of a zero-current-switched (ZCS) boost cascaded by- buck converter employed in a power factor correction (PFC) application. A combination of resonant inductor and capacitor are used to create ZCS during turn-off of switch. In addition, the designed control loop structure provides the variable DC link output voltages at PFC with universal input voltages. It also provides smooth input current and maintains a power factor of 0.99. Finally, the simulation and experimental results of the proposed converter are performed and efficiency of 96.4% is achieved.

This paper proposes a simple phase-shifted DC-DC converter for On-board battery chargers (OBC) with reduced circulating current. Two-stage battery chargers, are typically employed with a zero voltage switching phase shifted DC-DC converter in its layout. It contains a severe duty cycle loss, large circulating current region and limited range of soft switching with changes in load. To enhance its operation, a simple auxiliary circuit with a clamped capacitor and a resonant inductor is added in the secondary side of the converter. The various operation modes involved in the converter operation is detailed in the paper. Moreover, the proposed converter reduces the voltage and current stresses on the switches. This converter is applied with the power factor correction stage to attain battery charger with wide output voltages. The design of the converter is also detailed in this paper. The simulation results with a laboratory prototype of 1 kW has been presented in the paper.

In this paper, an off-board multi terminal dc charger with active input current shaping for level-3 electric vehicle (EV) charging applications is proposed. The proposed configuration is based on reduced switching state (RSS) multi-point clamped (MPC), three phase improved power factor converter (IPFC) and supplied by the standard ac grid. The topology has an advantage of reduced device count along with reduced maximum device stress. This will increase the speed of EV charging and elables the reduction of capital and maintenance costs of the charging facilities, enhancing further expansion of the ecofriendly transport. The validation of proposed topology is verified with simulation and a down scaled experimental setup.