Regenerative Braking Operation Research Articles

A Fuel-Efficient BLDC Motor-Driven Light Electric Vehicle With Single-Stage Onboard Charging System

This work proposed a simple, compact, and efficient scheme for an on-board charging configuration for light plug-in electric vehicles (LPEVs) with a dual charging arrangement i.e., utility grid and solar panel. The system is targeted to develop an LPEV with a low DC bus voltage (<100V) and on-board solar support using a brushless dc motor (BLDCM) drive due to its economic controller, compact drive arrangement, and high efficiency. The designed integrated converter works well under all operating modes like charging, propulsion (PP), and regenerative braking (RB) operations. The developed converter works as a power factor correction (PFC) converter during grid charging as well as performs as maximum power point tracking (MPPT) converter when charging through solar power. A new approach of the controller in regenerative mode exploiting both the drive and proposed integrated control is unique for this system. As a result, the designed system becomes compact and efficient, making it a competitive solution for an on-board charging scheme for LEVs.

An Economical Light Plug-in Electric Vehicle (LPEV) with On-Board Single-Stage Battery Charging System

This work proposes an efficient configuration for light plug-in electric vehicles (PEVs) with a cost-effective and compact charging system. In this work, an integrated isolated DC-DC converter is investigated for a light PEV that employs a brushless DC (BLDC) machine as a traction motor to lower the component cost of the motor drive. The designed converter has the ability to function competently in all operating situations. The proposed converter has a minimum element because of the multi-functional operation of the converter. The designed converter can function as both maximum power point tracking (MPPT) and power factor correction (PFC) converters in solar and grid charging. In propulsion and regenerative braking operations, the proposed converter has buck/boost conversion capability to adjust the DC bus voltage according to vehicle speed to lower the inverter switching power losses and the traction motor's current ripple. As an outcome, the developed charging scheme becomes condensed and effective, making it a viable alternative for industry applications of light plug-in vehicles.

Four Speed Auto Transmission DC-DC Converter Control for E-Vehicle and Regenerative Braking Based on Simulation and Model Investigation

A novel single input multioutput (SIMO) output DC-DC converter with circular capacitors is intended to function with a single independent source to create numerous transmissions to regulate the speed at the same switching intervals. A novel single input multi output (SIMO) output DC-DC converter employing circular capacitors is designed to work with a single independent source to create numerous transmissions. The proposed converter generates 7 outputs in total, with 4 outputs generated simultaneously for forward operation (speed transmission) using the preferred source (fuel cell/battery) and 3 other different outputs used for regenerative transmissions, with the battery being the preferred storage device. This converter can control the speed of an electric vehicle (EV) by using the SIMO is output voltage to regulate the vehicle is speed, allowing for higher accelerations and decelerations with minimal energy loss and degradation of the main battery pack. It can also be used to power electronic components such as LED lights, audio systems, and mobile charging etc. The energy recovered during regenerative braking is used to charge the battery via a buck/boost operation for varied speed transmission. In addition, simulation, modelling, and analysis are used to validate the proposed system. It is intended for a fixed voltage of 12 V and output voltages ranging from 12 to 48 V. The PSIM simulation tool is used to validate the system. The validation demonstrates the suggested converter is good evidence in both braking and regenerative braking operations.

High Voltage Gain Bidirectional DC-DC Converters for Supercapacitor Assisted Electric Vehicles: A Review

Integration of supercapacitor alongwith battery in electric vehicles (EVs) improves the life cycle of the battery. Additionally, supercapacitor supplies or absorbs a large amount of instantaneous power during sudden demand such as acceleration or regenerative braking operation, hence also improve the dynamics of the internal power system. However, a major challenge with supercapacitor is that its terminal voltage is low and varies in a wide range during charging and discharging operation. Thus, a high voltage conversion ratio based bidirectional DC-DC converters are required to connect the lower supercapacitor voltage to higher DC-link voltage. The steep voltage conversion ratio with continuous gain based bidirectional DC-DC converters are an integral part of such applications. Various high gain converters exist in the literature such as isolated, non-isolated, cascaded, switched, flying capacitor, and coupled inductor based DC-DC converters, however all these converters have some limitations in context to high gain/high power applications. Therefore, to understand the development of next-generation high voltage gain bidirectional DC-DC converter, this paper focus to comprehensively review and classify various bidirectional step-up DC-DC converters based on their characteristics and voltage-boosting techniques. Further, practical suitability of the reviewed converters and future research directions in switched capacitor converters in context to EVs are also discussed in detail.

Electrothermal Multicriteria Comparative Analysis of Two Competitive Powertrains Applied to a Two Front Wheel Driven Electric Vehicle during Extreme Regenerative Braking Operations

The powertrain performance in an electric vehicle is fully dependent on the electrical and thermal constraints of the static converters ensuring the power transfer taking place between the energy storage systems and the electromechanical machines. These constraints depend on the architectures of the power converters, and their control strategies. Particularly, the maximal limits are reached in maneuvers such as hard regenerative braking circumstances. Indeed, braking recovery is a critical phase in the vehicle’s operation, and its duration and intensity may strongly impact the vehicle’s battery behavior or integrated hybrid storage system. The innovative objective of the paper is to propose an electrothermal multicriteria comparative study based on electrical and thermal criteria for two competitive powertrains. These semi-active power configurations (a 3-level DC/DC converter-based, and a Z-source converter-based) are implemented in a two-front wheel driven electric vehicle during extreme regenerative braking conditions. Open-loop and closed-loop controls were implemented in the Z-source using the maximal constant boost control with 3rd harmonic injection modulation technique. We considered two paralleled IGBT modules instead of the single shoot-through structure. Our approach is based on simulation during an extreme braking maneuver leading to heavy repercussions on the overall powertrain system. The aim is to investigate the challenging structure of the Z-source. Results showed that the proposed 3-level DC/DC-based topology has better performances in terms of power losses, efficiency, thermal behavior, and electromagnetic interference.

SIMO DC-DC Converter for E-Vehicle and Regenerative Braking Based on Simulation and Model Investigation

A single independent voltage source (Vin or Vbat) is used to regulate the speed of an E-vehicle (EV) with the same interval of switching pulses to generate different voltage ratios by charging/discharging the flying capacitors using a novel single-input multi-output (SIMO) DC-DC switched capacitor converter. In this work, various speed transmissions are generated for controlling the speed of EVs. The selected and regulated battery voltage are generated using the SIMO DC-DC converter. The proposed converter is used to generate seven different transmission in total, of which four transmissions are used for motoring (forwarding operation) and the other three transmissions act as regenerative braking. For motoring operation, the battery, fuel cell, and photovoltaic cell are used as a sources of energy, and for the regenerative braking, the regenerated voltage is fed back to store the battery. The SIMO DC-DC converter is used to support electronic accessories, such as LED lights, the EV audio system and other accessories, including mobile and laptop battery charging. The energy recovered during regenerative braking is used to charge the battery via a proposed SIMO DC-DC converter for different speed transmissions. In addition, simulation, modeling, and analysis are used to validate the proposed system. It is intended for a fixed voltage of 12 V and output voltages ranging from 12 to 48 V. The PSIM simulation tool is used to validate the system. The validation demonstrates that the suggested converter shows good evidence for both braking and regenerative braking operations.

Control of an Electric Vehicle Hybrid Energy Storage System

Abstract In electric vehicles battery life can be prolonged by using hybrid energy storage systems (HESS ), which combine high energy density batteries with supercapacitors, characterized by high power density. This paper deals with the control of electronic power converters from an active parallel HESS. The load of the HESS is the electrical motor drive of an electric vehicle. The interfaces between the DC-link and the power sources are four-phase bidirectional DC-DC converters driven in current control mode, based on the current references supplied by an active parallel HESS power distribution algorithm. We present a rule-based fuzzy energy management algorithm for a HESS powered electric vehicle and its simulation in MATLAB/Simulink® environment using the Quasi-Static Simulation (QSS ) and Fuzzy Logic toolboxes. Also, simulation results in driving and regenerative braking operation modes of the electric vehicle are presented.

Design and implementation of algorithms for one pedal driving in electric buses

Nowadays, the interest in electric vehicles (EVs) is increasing in parallel with falling prices of batteries, developing battery technology and willing to reduce carbon emissions. However, the most important problem of EVs is still range anxiety. The one pedal driving (OPD), which uses only accelerator pedal to accelerate and decelerate the vehicle, is an alternative solution to further increase the energy efficiency by managing the regenerative braking operation of EVs. In this study, OPD algorithms are developed for an electric bus (E-Bus), which is equipped with a 100 kW electric motor. Algorithms manage the vehicle traction torque without compromising the comfort of the passengers in the vehicle. To evaluate the performance of the developed OPD algorithms for the heavy vehicle, experimental studies have been conducted. The energy efficiency performance of OPD has been tested under different speed profiles as urban traffic, constant speed and stop-and-go traffic. The energy recovery potential of OPD algorithms for different experience levels and driving characteristics of drivers, the adaptability of drivers to OPD driving have been examined for heavy electric vehicles first time. The results show that the OPD performs a precise energy efficiency by managing the regenerative braking operation.

Hybrid-electric passenger car energy utilization and emissions: Relationships for real-world driving conditions that account for road grade

Past research showed on-road emissions patterns unique to hybrid electric vehicles (HEVs), indicating the need to account for them in emissions models as projected HEV sales increase over the coming decades. This work defines and characterizes a variable that quantifies HEV operating behavior to inform future development of new HEV emissions models based on current knowledge of conventional vehicle (CV) emissions patterns. Instantaneous hybridization factor (IHF), was quantified using on-road data collected from a 2010 Toyota Camry HEV. IHF is the ratio of electric system power to total system power and accounts for energy storage in the high voltage battery (IHF ranges from −1 to +1). Relationships between IHF and vehicle specific power (VSP), road type and road grade were examined. Negative VSP resulted in regenerative braking operation (IHF = −0.01 to −1) 90% of the time. IHF identified the VSP range where HEV operation was highly variable (VSP = −1 to 8 kW/ton) when driving at speeds below the ICE-off threshold (42 mph). VSP and IHF together account for 76–86% of the variability in HEV CO2 emissions in this study. CO2 model results using VSP computed with the measured real-world road grade (R2 = 0.86) gave improved fits over the no-grade VSP model (R2 = 0.69). This study establishes one framework for calculating the instantaneous HEV power split, confirms the need to include road grade in VSP for accurate modeling of vehicle emissions, and identified the need for significant improvements in on-board diagnostic (OBD) scantool measurement requirements for HEVs in three areas: (1) temporal resolution (sub-second to capture transient events such as ICE restarts); (2) simultaneous data logging capability for multiple controller area networks (i.e., engine and HEV parameters together); and (3) improved data precision.

DC-DC Converter used for Series-Parallel Hybrid Electric Vehicle

Recently, the area of Hybrid Electric Vehicles (HEV) has seen a tremendous growth all over the world. Due to increasing levels of emissions from the conventional vehicles, rising fuel prices and environmental concerns due to global warming, entire focus of automotive industry is shifted to development of HEV’s. The HEV’s are classified into various configurations depending upon the degree of hybridization which include the performance of the IC engine and electric battery simultaneously for the traction purpose. The physical overview and modeling of Hybrid electric vehicle is discussed. The importance of the dc-dc converter which acts as an interface between battery and the motor drive for bi-directional power flow is proposed .In this paper, bi-directional full bridge dc-dc converter and its implementation in Series-Parallel HEV is presented .This converter topology accounts for motoring as well as regenerative braking operations.

Using Approximate Dynamic Programming to Maximize Regenerative Energy Utilization for Metro

With the rapid development of Metro, it has aroused more attention to its energy efficiency. The regenerative energy is a kind of energy generated by a braking train, which can be used by other trains nearby. Due to the application of regenerative braking and automatic train operation function, more and more studies focus on using regenerative energy by optimal train control. To maximize the utilization of regenerative energy for a couple of trains, we formulate a model and design an algorithm for maximizing the utilization of regenerative energy (MURE) by using the proposed approximate dynamic programming (ADP) approach to adjust the speed curve of the accelerating train. Then, we discuss three approximation methods for the proposed ADP-based approach such as rollout method, interpolation method, and neural network. The rollout algorithm could improve the basic policy for train control with carefully designing. The function approximation method using interpolation could further decrease the energy consumption with assuring punctuality. The neural network approximation usually cannot realize the effect superior to the interpolation strategy due to its complex structure, and it needs more computation time. Finally, the analysis of regenerative energy utilization is given by implementing the numerical experiments with field data from the Yizhuang line, Beijing subway. The numerical results show its effectiveness and stability.

An Open-Circuit Fault Diagnosis Approach for Single-Phase Three-Level Neutral-Point-Clamped Converters

This paper presents a model-based open-circuit fault diagnosis approach for single-phase three-level neutral-point-clamped (3LNPC) converters in electric railway application. The diagnosis algorithm, which only requires the signals existing in the control system, not only detects open-circuit faults but also identifies the faulty device among the transistors and clamping diodes. The mixed logical dynamic (MLD) model of the converter is built to estimate the grid current. The residual generated from the measured current subtracting the estimated one is analyzed under different open-circuit faults. According to the characteristics of the residual changing rate, the proposed approach allows fault localization. The proposed method is effective both in traction and regenerative braking operation and has fast diagnosis speed. Hardware-in-the-loop (HIL) experiments are carried out to verify the effectiveness of the proposed fault diagnosis algorithm.

Configuration Study of Hybrid Electric Power Pack for Tracked Combat Vehicles

&lt;p&gt;In recent years, there is growing interest in hybridisation of military vehicles due to the features and advantages offered by the technology. Generally, the hybrid electric vehicle (HEV) is propelled by a combination of electric motors and internal combustion engine (ICE). Hybrid electric combat vehicles, when compared with conventional vehicles, have the advantages of improved fuel efficiency and drivability due to optimal operation of ICE, regenerative braking and silent operation capability. Limitations related to key technologies such as compact electric motors/generators, power electronics and energy storage systems that are required to operate under extreme environmental conditions pose challenges to the development of hybrid electric power pack. Technical challenges of HEV technologies considering futuristic applications of combat vehicles is described. The configuration specification of hybrid electric power train architecture suited to deliver high automotive performance and power demands for infantry combat vehicles (ICV) is also discussed.&lt;/p&gt;

Comparative analysis of two hybrid energy storage systems used in a two front wheel driven electric vehicle during extreme start-up and regenerative braking operations

This paper presents the comparative study of two hybrid energy storage systems (HESS) of a two front wheel driven electric vehicle. The primary energy source of the HESS is a Li-Ion battery, whereas the secondary energy source is either an ultracapacitor (UC) or a flywheel energy system (FES). The main role of the secondary source is to deliver/recover energy during high peak power demand, but also to increase battery lifetime, considered among the most expensive items in the electric vehicle. As a first step, a techno-economic comparative study, supported by strong literature research, is performed between the UC and the FES. The design and sizing of each element will be presented. The comparison criteria and specifications are also described. The adopted approach in this paper is based on an academic non-oriented point of view. In a second step, each of the HESS will be integrated in a more global Simulink model which includes the vehicle model, the traction control system (TCS), the regenerative braking system and the vehicle actuators. Simulation tests are performed for an extreme braking and vehicle starting-up operations. Tests are realized on two different surface road types and conditions (high and low friction roads) and for different initial system states. In order to show the most appropriate storage system regarding compactness, weight and battery constraints minimization, deep comparative analysis is provided.

An Electric-Vehicle IPMSM Drive With Interleaved Front-End DC/DC Converter

This paper presents the development of an electric-vehicle (EV) interior permanent-magnet synchronous motor (IPMSM) drive and its operation control. The power circuit of the established EV IPMSM drive consists of a two-leg interleaved bidirectional front-end dc/dc buck–boost converter and a three-phase inverter. The front-end converter can establish adjustable and boostable dc-link voltage for the motor drive to enhance its high-speed driving performance. It can also allow the battery bank to be charged from the motor during regenerative braking. Good current sharing control between converter modules and dc-link boosted voltage regulation response are preserved via the developed robust control scheme. Moreover, fast disturbance rejection response against the module fault and recovery is achieved. The comparative driving performance enhancements via dc-link voltage boosting and commutation instant tuning are conducted. Then, through proper setting and control, the established EV IPMSM drive possesses good driving performances, including starting, acceleration/deceleration, regenerative braking, and reversible operation characteristics.

Analysis of forces in single‐side linear induction motor with lateral displacement for linear metro

This study investigates the influence of lateral displacement of the primary on the thrust, vertical and lateral forces in a single-side linear induction motor for linear metro. A three-dimensional analytical model, which is able to consider the longitudinal and transversal end effects, overhang of the primary windings and lateral displacement, is developed to obtain the air-gap flux density distributions along longitudinal and transverse directions as well as forces. Variations of the thrust, vertical and lateral forces with the lateral displacements are comprehensive investigated when the motor is torque motoring, negative sequence braking or regenerative braking operation. The analytically predicted results are experimentally validated by measurements on reciprocal power-fed test rig. It shows that the thrust and vertical force of single-side linear induction motor decrease almost linearly with the increase of the lateral displacement in all regions, and lateral force is restoring which helps centralising the railcar in the regenerative braking and most parts of motoring regions.

Incorporated Operation Control of DC Microgrid and Electric Vehicle

This paper presents the establishment and operation control of a dc microgrid incorporating with electric vehicle (EV) as movable energy storage. The developed microgrid consists of a wind permanent-magnet synchronous generator ac source and a dc source, a battery/supercapacitor (SC)/flywheel hybrid energy storage system, and a grid-connected bidirectional single-phase three-wire (1P3W) load inverter. Various harvested ac and dc sources can be plugged into the microgrid via the developed interfaced power converters. In addition to good microgrid operation performance, the microgrid-to-grid and grid-to-microgrid operations can be successfully conducted with good power quality. As to the developed EV interior permanent-magnet synchronous motor drive, the SC auxiliary storage is equipped to assist the main battery source in intermittent energy conversion. Satisfactory acceleration/deceleration/reversible and regenerative braking operation characteristics are obtained via the developed power stages and control schemes. Moreover, the successful microgrid-to-vehicle and vehicle-to-microgrid interconnected operations of EV and microgrid are achieved. In addition, the vehicle-to-grid/grid-to-vehicle operations can be also performed via the developed 1P3W inverter.

Effects of Rotor Position Error in the Performance of Field Oriented Controlled PMSM Drives for Electric Vehicle Traction Applications

This paper analyzes the effects of the rotor position error in the performance of field-oriented-controlled permanent-magnet synchronous machine (PMSM) drives intended for electric vehicle (EV) traction applications. A special focus is given to the torque ripple generated along the characteristic trajectories in the different operating regions of the PMSM. An extended and generalized model of the torque ripple produced by the PMSM as a function of the rotor position error is analytically deduced. An infinite-speed interior-(I)PMSM drive and a finite-speed surface-mounted (SM)-PMSM drive are considered for the simulations carried out in MATLAB-SimPowerSystems. The experimental results have been validated with a TM4 EV drive controlling an 80-kW SM-PMSM. The torque ripple has been evaluated for both motoring and regenerative braking operation modes under maximum torque conditions going from 100 N · m at 1000 r/min up to 55 N · m at 9000 r/min. The obtained simulation and experimental results demonstrate the good accuracy of the proposed model for evaluating the torque ripple produced in PMSMs due to the error from the rotor position sensor.

Efficient braking energy recovery using bidirectional step-up converter in fuel cell and battery electric vehicles

The topology of the power conditioning unit (PCU) that is used with energy storage system (ESS), has a vital role especially in braking energy recovery. In recent studies, conventional bidirectional half-bridge topology is widely used as a PCU for ESSs. Due to its structure, it does not have the capability of capturing braking energy when the voltage across the motor terminals is lower than ESS voltage. This study investigates the feasibility of utilising a PCU with stepping up capability in regenerative braking operation mode, focusing on the additional braking energy that can be captured in comparison with that of the conventional half-bridge buck/boost converter. In order to verify the advantageous of the proposed approach in braking energy recovery, two 1 kW prototypes, a conventional half-bridge buck-boost and cascaded buck-boost converters are designed and tested for three different drive cycles including normalised version of ECE-15.

Energy Management and Control of Electric Vehicles, Using Hybrid Power Source in Regenerative Braking Operation

Today’s battery powered electric vehicles still face many issues: (1) Ways of improving the regenerative braking energy; (2) how to maximally extend the driving-range of electric vehicles (EVs) and prolong the service life of batteries; (3) how to satisfy the energy requirements of the EVs both in steady and dynamic state. The electrochemical double-layer capacitors, also called ultra-capacitors (UCs), have the merits of high energy density and instantaneous power output capability, and are usually combined with power battery packs to form a hybrid power supply system (HPSS). The power circuit topology of the HPSS has been illustrated in this paper. In the proposed HPSS, all the UCs are in series, which may cause an imbalanced voltage distribution of each unit, moreover, the energy allocation between the batteries and UCs should also be considered. An energy-management scheme to solve this problem has been presented. Moreover, due to the parameter variations caused by temperature changes and produced errors, the modelling procedure of the HPSS becomes very difficult, so an H∞ current controller is presented. The proposed hybrid power source circuit is implemented on a laboratory hardware setup using a digital signal processor (DSP). Simulation and experimental results have been put forward to demonstrate the feasibility and validity of the approach.