Hybrid CryStAl and Random Decision Forest Algorithm Control for Ripple Reduction and Efficiency Optimization in Vienna Rectifier-Based EV Charging Systems

The rise in Electric Vehicle (EV) usage has significantly increased the need for high-power fast charging systems that must meet rigorous performance standards. This paper examines the performance of 50 kW grid-connected EV charger. The design of the charger utilizes a dual stage Vienna rectifier at the front end, combined with a bi-directional DC-DC stage, to achieve a high-power factor, minimize total harmonic distortion (THD), and maintain stable operation of the DC bus. Vienna rectifiers are commonly utilized in high-power electric vehicle chargers because of their excellent efficiency greater than 94% and nearly unity power factor. An analysis of 50 kW charger that employs a Vienna rectifier focuses on its output ripple, input signal distortion, and power input factor. Under standard operating conditions, the performance remains equable. However, once the battery charge status surpasses 80%, the notable decline in performance occurs. In this scenario, both ripple and THD increase, and the power factor strays from unity, potentially harming the battery State of Health (SOH) during constant-voltage charging. Based on research results, this paper quantified the implication of current ripple on conversion efficiency in Electric vehicle charger through experimental verification and the results communicate that the current ripples have important influence on EV chargers.

The first electric vehicles (EVs) debuted in the last decades of the nineteenth century when electricity was becoming increasingly popular to power motor vehicles. EVs power the battery packs with electricity rather than petroleum-based energy sources like gasoline or diesel. EV chargers will significantly influence the adoption of EVs. A battery is required to power the EV. Since this battery needs to be charged regularly, the reduced grid-side power factor in existing converters is caused by increased input current harmonics, which occurs only under extreme conditions. The Vienna rectifier is superior to other options for excess power due to its ability to raise the voltage at the output, diminish ripple and enhance efficiency and power factor. The Vienna Rectifier is an excellent front-side converter for applications requiring rapid DC battery charging. Here, the proposed charger charges the batteries using a two-stage conversion system consisting of a Vienna rectifier and buck converter. An EV can be charged using a variety of methods where several complicated parameters are required, as well as AC and DC charging at high power levels. To facilitate this, the Indian government developed Bharat DC 001, the standard for Direct Current (DC) charging and Bharat AC 001, the standard for Alternating Current (AC) charging, for EV chargers. The Bharat EV Charger Protocol was created expressly to regulate India's EV charging ecosystem. Based on the Bharat DC001 standard, this work suggests a two-way DC rapid charger. The Bharat DC001 standards for EV charging stations can simultaneously power two EV batteries with ratings of 72 and 48 volts at charging levels of up to 14.5 kW and 9.6 kW, respectively. The paper provides an analysis of the proposed Vienna rectifier topology and derives the mathematics model from a three-level vector to a two-level vector model. In addition, a well-known SVPWM control technique is implemented to enhance input-side power quality, reduce switching losses and reduce the total harmonic distortion value. Thus, the proposed architecture with its control technique is simulated using MATLAB/SIMULINK to validate the results.

The Power Factor Correction (PFC) in Switched Reluctance (SR) motor is discussed in this article. The SR motors are applicable for multiple applications like electric vehicles, wind mills, machineries etc. The doubly salient structure of SR motor causes the occurrence of torque ripples, which affects the power factor of the motor. To improve the power quality, the power factor has to be corrected and the ripples have to be minimized. In order to achieve these objectives, a novel power factor correction (PFC) method is proposed in this work. Here, the conventional Diode Bridge Rectifier (DBR) is replaced by a Bridgeless Hybrid Resonant (HR) converter, which assists in improvising the output in a wider range. The converter is chosen because of having variety of beneficial measures including high gain. The converter’s output is fed to the SR motor by means of an asymmetric Bridge Resonant (BR) converter. The proposed converter operates in continuous mode of conduction with the switching frequency of 10 KHz. A hysteresis current controller and Proportional Integral (PI) controller are utilized for reducing the harmonics in the source current along with the regulation of output voltage. In addition, the speed control of SR motor is accomplished by means of the Whale Optimization Algorithm (WOA) assisted PI controller. The proposed methodology is effective for the control of unity power factor, torque and current ripples. The Total Harmonic Distortion (THD) of the source current is also minimized, which suits the standard of International Electrotechnical Comission IEC 61000-3-2. By this methodology, the power factor of 0.99 is achieved with 97% efficiency and 3.92% THD. The proposed methodology is validated in simulation by MATLAB and in hardware by FPGA Spartan 6E.

There is a need to improve the power quality of the grid as well as the power factor implied on the grid due to the nonlinear loads connected to it. A new single phase bridgeless AC/DC power factor correction (PFC) topology to improve the power factor as well as the total harmonic distortion (THD) of the utility grid is proposed in this research. By eliminating the input bridge in conventional PFC converters, the control circuit is simplified; the total harmonics distortion THD and power factor PF are improved. The controller operates in multi loop fashion as the outer control loop calculates the reference current through innovative filtering and signal processing. Inner current loop generates PWM switching signals through the PI controller. Analytical derivation of the proposed converter is presented in detail. Performance of the proposed PFC topology is verified for prototype using PSIM circuit simulations. The experimental system is developed, and the experimental results agree with simulation results.

Energy-efficient Vienna rectifier for electric vehicle battery charging stations

Electronic devices such as SMPS, UPS, rectifier and electronic ballast primarily require DC power supply. Electronic switching devices draw highly distorted input current (spikes with respect to the line voltage) for a short duration, due to their non-linear nature. This results in interference with other electrical equipment, increase in Total Harmonic Distortion (THD) and poor Power Factor (PF), which further results in poor output voltage regulation. Power factor correction (PFC) circuits are being increasingly used to mitigate the problems associated with poor power factor. This paper discusses an Active Power Factor Correction (APFC) technique using voltage feed forward and voltage feedback loop. It is based upon current wave shaping technique to get the source current in phase with the input voltage. Current wave shaping is achieved by implementing voltage control loop and current control loop. This paper explains the development of boost converter as a power factor correction controller, operating in continuous conduction mode (CCM). The boost converter is also designed to regulate the output voltage. The prototype of boost active PFC has been developed for single-phase rectifier, supplying load of 80W at 400V DC. Analysis has been carried out for different load conditions which prove that the PF can be improved from 0.6 to 0.98∼0.99 with THD reduction.

In this work, a medium and high power rating electric vehicle (EV) charger based on Vienna rectifier (VR) and half bridge resonant inductor-inductor-capacitor (LLC) converter, is presented. The two switch VR forms the front-end converter, and performs active power factor correction (PFC), by operating under continuous conduction mode (CCM). Moreover, its output voltage is regulated by an outer voltage control loop, in a two loop pulse width modulated (PWM) control. The EV battery is charged using constant voltage (CV) and constant current (CC) controller by a pulse frequency modulation (PFM) based half bridge LLC converter. The DC-DC conversion stage of this charger is soft switched due to zero voltage switching in LLC converter. Simulation results and its performance under steady state and dynamic conditions, are presented. Moreover, the power quality (PQ) and steady state results are verified and presented for a 5.6kW experimental prototype.

In order to reduce the system cost, volumetric size and weight of an electric vehicles (EVs) battery charger, a novel four-switch two-leg VSI configuration is propose for rapid battery charging with the active power filter (APF) features. It consists of cost-effective two-arm bridge converter, coupling inductors, LC filters, buck converter and EV battery. Note that the conventional three-leg bridge structure is reduce to two-leg VSI structure, functioning like three-phase rectifier to converts power from ac-dc during the battery charging process. The third-leg and set of power switching devices are eliminate by directly connecting the grid phase with the negative terminals of dc-link capacitor. Therefore, third leg of the EV charger is use as a buck converter for battery charging. The charger controller ensures the rapid charging capabilities in constant current and constant voltage (CC-CV) modes, with additional functions of harmonic compensation capability, power factor correction, reactive power compensation and constant dc-link voltage. The experimental results verify the validity and effectiveness performance of the laboratory based EV charger prototype.

A topological review of the single stage power factor corrected (PFC) rectifiers is presented in this paper. Most of reported single-stage PFC rectifiers cascade a boost type converter with a forward or a flyback DC-DC converter so that input current shaping, isolation, and fast output voltage regulation are performed in one single stage. The cost and performance of a single-stage PFC converters depend greatly on how its input current shaper (ICS) and the DC-DC converter are integrated together. For the cascade connected single-stage PFC rectifiers, the energy storage capacitor is found in either series or parallel path of energy flow. The second group appears to represent the main stream. Therefore, the focus of this paper is on this group. It is found that many of these topologies can be implemented by combining a 2-terminal or 3-terminal boost ICS cell with DC-DC converter along with an energy storage capacitor in between. A general rule is observed that translates a 3-terminal ICS cell to a 2-terminal ICS cell using an additional winding from the transformer and vice versa. According to the translation rule, many of reported single-stage PFC topologies can be viewed as electrically equivalent to one another. Several new PFC converters were derived from some existing topologies using the translation rule.

In this paper, a series-capacitor-based interleaving buck power factor correction (PFC) converter is proposed, the intermediate energy storage capacitance of which is operated at discontinuous capacitor voltage mode (DCVM), and automatic power factor (PF) correction for this converter is obtained. Moreover, the voltage across the series capacitor of the proposed PFC converter is clamped at the input voltage, and thus peak voltage stress existed in the traditional DCVM buck PFC could be relieved. By effectively regulating the charge/discharge time for the series capacitor, ultrahigh step-down conversion ratio of the proposed converter is achieved, the conversion ratio of which is independent of the duty cycle and only related to the switching frequency and circuit parameters. Therefore, high PF can be obtained due to very narrow deadtime of the input current. Meanwhile, the proposed PFC converter can realize the soft turn- on of part power switch and soft turn- off of part power diodes. In addition, comparing with the traditional discontinuous inductor current mode PFC, the input current of the proposed PFC converter is continuous so that the peak value and root-mean-square value of input current can be reduced. The operational principle, performance analysis, and parameter design principle are given in this paper. The analysis results show that the PF and total harmonic distortion are also independent of the duty cycle. Finally, a 220-Vac input, 60 W/15 V output experimental prototype is built to verify the validity of the theoretical analysis.

The use of wireless charging technology for Electric Vehicles (EVs) is gaining increasing significance due to its ability to charge batteries safely and conveniently without the need for physical connectors. This paper presents the design and implementation of the transmitter-side power conversion system for a wireless EV charging station. The proposed system architecture integrates a front-end Power Factor Correction (PFC) rectifier, an Interleaved Resonant DC-DC converter, and a three-level Neutral Point Clamped (NPC) inverter, providing a highly efficient and stable power transmission path for battery charging. The Interleaved Resonant DC-DC converter, designed with a Zero Voltage Switching (ZVS) mechanism, minimizes switching losses and enhances overall efficiency. Its operation under Constant Current (CC) and Constant Voltage (CV) control modes ensures smooth and reliable mode transition through an auxiliary controller incorporated alongside a conventional PI controller. The inverter stage adopts a Modified Space Vector Pulse Width Modulation (MSVPWM) strategy that significantly reduces Total Harmonic Distortion (THD) in both voltage and current waveforms, thereby maintaining compliance with power quality standards. The complete system's performance has been evaluated through both simulation and experimental validation. MATLAB/Simulink-based analysis demonstrates stable converter dynamics with a regulated output voltage of 325 V and negligible transient disturbances during mode transitions. A 0.2 kW laboratory prototype was developed to confirm the simulation results using PIC24F16KA102 and FPGA-SPARTAN-7 controllers for power and switching signal generation, respectively. Experimental measurements indicate that the proposed Interleaved Resonant DC-DC converter achieved an efficiency of approximately 95.35% at rated load, which aligns closely with theoretical predictions. The three-level NPC inverter produced a 320 V output with voltage and current THD levels of 4.8% and 5.6%, respectively. A 2:1 air-core transformer designed for high-frequency operation (100-200 kHz) effectively transfers power to the EV receiver side. The influence of coupling coefficient and air-gap variation on transfer efficiency was systematically investigated, revealing an optimal separation distance of 10-20 mm. The overall results confirm the efficacy of the proposed design for high-efficiency wireless EV charging. Future work will concentrate on optimizing the receiver-side converters to further enhance system efficiency and dynamic performance.

Three-phase three-level Vienna rectifier using powder core inductors has been widely used for power conversion. Inductor current ripple analysis of rectifier is essential for pulsewidth modulation method optimization, loss estimation, filter inductor design, etc. However, it is hard to analyze the current ripple of Vienna rectifier. Moreover, the inductance of powder core inductor varies with sinusoidal input current, which makes it even more complicated. In this article, a current ripple analysis method for three-phase Vienna rectifier considering the inductance variation of the powder core inductor is presented. The current ripple distribution of Vienna rectifier with constant inductance is studied based on the space vector approach. To determine the current ripple of Vienna rectifier with powder core inductors, an inductor voltage calculation method considering inductance variation is proposed. The compensation voltage is introduced to compensate for the effect of inductance variation on current ripple. Then, the analytical expression of the peak-to-peak current ripple with powder core inductor is derived. In addition, a design method of powder core inductor is proposed based on the analytical expression. At last, the correctness of the analytical result is verified by both simulation and experiment.

Most of the two-stage converters for electric bike battery charging comprise of a boost converter for power factor correction (PFC) followed by a dc–dc converter with universal input voltage. These two-stage conversions suffer from poor efficiency and increased component count. In this paper, a single-stage switched inductor Cuk converter based PFC converter is proposed, which offers high step-down gain, low current stress, high efficiency, and reduced component count. The operational analysis and design equations for various components of the proposed converter are carried out in continuous current mode. This paper presents mathematical modeling, analysis, simulation, and experimentation on the proposed converter rated for 500 W, 48 V/10.4 A. The performance investigation of the proposed converter with respect to power quality indices like voltage total harmonic distortion (THD), current THD, and total power factor is carried out with various types of loads such as resistive load and battery load in both constant voltage (CV) and constant current (CC) mode. Furthermore, the dynamic performance of the proposed converter with battery charging is investigated in CV mode and CC mode with respect to the wide range of supply variations.

Nowadays electric vehicles (EVs) are the most popular due to their cost-effectiveness and as an alternative to traditional petroleum fuel-based vehicles. When EV is charged from the utility grid conventional AC-DC converter act as a nonlinear load drawing peaky current from a supply and results in a very poor input power factor. The converter present at the input AC side which converts alternating current (AC) into direct current (DC), a crucial part of an electric car battery charging system, must have high efficiency. The topologies for use at the ac input side to convert ac into dc for EV battery charging are evaluated in this paper. The focus is on boost converter-based power factor correction converters, which provide excellent efficiency, good power factor, and affordable pricing. Traditional boost power factor correction converter, interleaved boost power factor correction converter, and bridgeless totem pole boost power factor correction converter are the topologies under investigation. The performance of all these topologies is simulated using Matlab/Simulink. All converters give the output of 400 V DC from a universal ac input voltage with a Total Harmonic Distortion (THD) percentage level that satisfies the IEEE Standards are provided with their simulation results.

Permanent magnet synchronous motor (PMSM) is the most widely used motor in electric vehicles (EV) due to its high power density and high efficiency. Conventional direct torque control (DTC) is developed to improve the performance of speed response of the PMSM drive but it suffers from higher torque ripples. Therefore a space vector modulation (SVM) based DTC has been developed to enhance the speed response. Due to the use of flux comparator and torque comparator conventional DTC has disadvantages such as higher torque and current ripples at steady state. To improve the performance of PMSM drive a space vector pulse width modulation is used with 3 level NPCI. To improve the performance of 2 level inverter in the PMSM drive is replaced with a neutral point clamped inverter (NPCI). Also, the switching selection strategy of SVM is modified using nearest three space vector pulse width modulation to reduce the total harmonic distortion (THD) in the inverter output. The simulation outcome proves that the SVM technique implementation in DTC for 3 level NPCI yields good performance for PMSM.KeywordsElectric vehicles (EV),voltage source inverter (VSI)Direct torque control (DTC)Neutral point clamped inverter (NPCI)Permanent magnet synchronous motor (PMSM)Space vector modulation (SVM)Total harmonic distortion (THD)