Browse Topic: On-board vehicle charging systems

Items (52)

Quantitative Analysis of a Hybrid Electric HMMWV for Fuel Economy Improvement

2024-01-3356

04/23/2025

ABSTRACT This paper presents a quantitative analysis and comparison of fuel economy and performance of a series hybrid electric HMMWV (High Mobility Multi-purpose Wheeled Vehicle) military vehicle with a conventional HMMWV of equivalent size. Hybrid vehicle powertrains show improved fuel economy gains due to optimized engine operation and regenerative braking. In this paper, a methodology is presented by which the fuel economy gains due to optimized engine are isolated from the fuel economy gains due to regenerative braking. Validated vehicle models as well as data collected on test tracks are used in the quantitative analysis. The regenerative braking of the hybrid HMMWV is analyzed in terms of efficiency from the kinetic energy at the wheels to the portion of regenerative power which is retrievable by the battery. The engine operation of both the series hybrid and conventional HMMWV are analyzed using a 2-D bin analysis methodology. Finally, the vehicle model is used to make

Nedungadi, Ashok, Masrur, Abul, Khalil, Gus

Quantitative Analysis of a Hybrid Electric HMMWV for Fuel Economy Improvement

2024-01-3356-TEST-REC11/15/2024

Nedungadi, Ashok, Masrur, Abul, Khalil, Gus

A Study on Effect of Regenerative Braking on Vehicle Range and Axle Life.

2024-26-024001/16/2024

During braking condition in EVs, the braking energy is split between the friction braking & regenerative braking. The friction brake fraction will be lost as heat & regenerative brake fraction is converted into electrical energy. In regeneration mode the amount of energy harnessed depends on the regenerative torque available & the rate at which that torque is achieved. If the regenerative torque is higher and if the rate of achieving that torque is higher, energy harnessed will be higher. But higher regenerative torque & higher rate of torque affect the life of the axle components like bevel gear, crown wheel pinion, spider gear & bearing etc & causes gear failure like gear pitting on coast side if proper regeneration torque maps are not defined. This paper gives an outline on effect of different regenerative braking torque values and their rate on the vehicle range and reliability, failure & life of the axle components. Initially an ideal situation with 100% regeneration torque

S, Srivatsa, Pethkar, Shivanand, Ghosh, Sandeep

Study on Range Improvement Controls and Method for Electric Vehicles

2024-26-013201/16/2024

Electric Vehicles are rapidly growing in the market yet various failure incidents were noted all along the globe. On the other hand, range anxiety has greatly inspired manufacturers to explore new practices to improve. One of the most important components of an EV is the battery, which converts chemical energy to electrical energy thereby liberating heat energy as the loss. This heat loss when high, capability of system to deliver required energy to wheels is reduced significantly. With a higher heat loss in the battery, system is prone to failure or reduced mileage. Therefore, controlling/maintaining system temperature under safe usable zone even during harsh conditions is ideal. Simple reduction in energy consumption of electrical cooling/heating devices used with regenerative energy techniques can greatly help in range improvement. The intention of this paper is to explore easy methods to improve electric vehicle range in different ambient conditions. Few of the key benefactors here

MR, Vikram, Pattalwar, Ashutosh, Verma, Mrinal, Bawa, Vikas

Regeneration Calibration for optimum Range and effective brakes performances in eSUV

2024-26-011001/16/2024

Regenerative braking is an effective approach for electric vehicles (EVs) to extend their driving range. To enhance the braking performances and regenerative energy, regenerative braking control strategy based on multi objective optimisation is explained in this paper. This technical paper would be focusing on extracting optimum Range with effective brake performances without affecting drivability and performances in different drives modes. An extensive research study on public road driving patterns is done to understand the percentage utilisation of brakes at various (low-mid-high) speeds as per the customer driving behavior. Multi-Objective optimisation function with three vital factors is defined where output generated power, torque smoothness and current smoothness are selected as optimisation objective to improve the driving range, braking comfort, and battery lifetime respectively. Braking regeneration maps are calibrated along with optimised foundation brake hardware’s to get

KUMAR, Prabhakar, K, Rajakumar, Krishnan, Nandhakumar, Suhail, Mohammed thamjeed

Electric Bus NVH Challenges and Refinement Using Innovative Approach

2025-01-008005/05/2023

The trend towards electrification propulsion in the automotive industry is highly in demand due to zero-emission and becoming more significant across the world. Battery electric vehicles have lower overall noise as compared to conventional I.C Engine counterparts due to the absence of combustion engine noise. However, other narrowband and tonal noises are becoming dominant and are strongly perceived inside the cabin. With the ongoing push towards electrification, there is likely to be increased focus on the noise impact of gearing required for the transmission of power from the electric motor to the road. Direct coupling of E-motors with Axle has resulted in severe tonal noises from the driveline due to instant e-motor torque ramp up from 0 rpm and reverse torque on driving axle during regenerative braking. The tonal noises from the rear axle during vehicle running become very critical for customer perception. For automotive NVH engineers, it has become a challenge to balance expected

Doshi, Sohin, Kalsule, Dhanaji, Sawangikar, Pradeep, Suresh, Vineeth, Sharma, Manish

Comparison of On-Road Highway Fuel Economy and All-Electric Range to Label Values: Are the Current Label Procedures Appropriate for Battery Electric Vehicles?

2023-01-0349

04/11/2023

As consumers transition from internal combustion engine (ICE)-powered vehicles to battery electric vehicles (BEV), they will expect the same fuel economy label-to-on-road correlation. Current labeling procedures for BEVs allow a 0.7 or higher multiplier to be applied to the unadjusted fuel economy and range values. For ICE-powered vehicles, the adjustment factor decreases with increasing unadjusted fuel economy and can be lower than 0.7. To better inform consumers, starting in 2016, Car and Driver added an on-road highway fuel-economy test, conducted at 120 kph (75 mph), that augments the performance metrics that it's been measuring since the 1950s. For electric vehicles, testing includes an evaluation of the all-electric range.The on-road test results were aligned with the certification information for each vehicle model including unadjusted and label fuel economy and range, road load force coefficients, and labeling options. Tractive energy and kinetic energy available for

Pannone, Gregory, VanderWerp, Dave

Estimating Brake Pad Life in Regenerative Braking Intensive Vehicle Applications

2022-01-116109/19/2022

Regenerative braking without question greatly impacts brake pad service life in the field, in most cases extending it significantly. Estimating its impact precisely has not been an overriding concern - yet – due in part to the extensive sharing of brake components between regen-intensive battery-electric and hybrid vehicles, and their more friction-brake intensive internal combustion engine powered sibling. However, a multitude of factors are elevating the need for a more accurate estimation, including the emerging of dedicated electric vehicle architectures with opportunities for optimizing the friction brake design, a sharp focus on brake particulate emissions and the role of regenerative braking, a need to make design decisions for features such as corrosion protection for brake pad and pad slide components, and the emergence of driver-facing features such as Brake Pad Life Monitoring. Tackling this question raises questions such as “is the proven braking energy and temperature

Antanaitis, David, Robere, Matthew

Novel Nanocrystalline Silver Alloy Coatings to Boost Performance of EV High Voltage Interconnects and Charging Interfaces

2022-01-087403/29/2022

Electric vehicle performance needs challenge connector designers and powertrain engineers with new paradigms for performance under more rigorous operational conditions. Traditional connector design protocols direct the engineer to silver plating for the contact interface, but these coatings have a maximum interface temperature of 170 C (ambient temperature plus T-rise). To avoid thermal runaway, engineers have to derate the ampacity of powertrain connections, which reduces available energy delivery as the temperature increases. This is especially true during transient power events like regenerative braking and acceleration. The soft nature of silver coatings make them well suited for power delivery and low contact resistance, but requires an engineering trade-off for wear durability. This is especially problematic for charging connectors which require tens of thousands of mating cycles before failure. In this work, we demonstrate the performance enhancements that can be achieved using

Griffiths, Peteris, HILTY, Robert, Chan, Lisa, Cahalen, John

Rule-based Power Management Strategy of Electric-Hydraulic Hybrid Vehicles: Case Study of A Class 8 Heavy-Duty Truck

2022-01-090103/29/2022

Mobility in the automotive and transportation sector has been experiencing a period of unprecedented evolution. A growing need for efficient, clean and safe mobility has made a strong momentum toward sustainable technologies in this sector. Toward this end, battery electric vehicles have drawn keen interest and the market share is expected to grow significantly in the coming years, especially in light-duty applications such as passenger cars. Although battery electric vehicles feature high performance and zero emissions characteristics, economic and technical issues such as high battery cost, a short driving range, and limited infrastructure should be tackled. In particular, the low power density of battery electric vehicles limits their broad adoption in heavy-duty applications such as class 8 long haul trucks due to a size and weight of battery. In this work, motivated by the high power density and potential for improving energy efficiency through regenerative braking of a hydraulic

Yoon, Yongsoon, Romero, Giovanni, Nkemdilim-Dantzler, Emil, DelVescovo, Dan, Guessous, Laila

Proving Ground Durability Test Schedule Development for Electrified Vehicle Drivelines using Virtual Simulations

2022-01-079003/29/2022

A new method is presented for developing proving ground durability tests for electrified vehicle (xEV) drivetrains. For xEVs, the durability tests must be able to capture the added driveline torques due to regenerative braking, customer battery charge/recharge usage, and battery power degradation over time. In terms of xEV duty cycle test schedule development, using actual vehicle data from specific proving ground test events might prove to be costly and time consuming. Furthermore, newer electrified prototype vehicles might not be available for trackside testing while still undergoing the design stage. The new method presented here aims to reduce the complexities of xEV proving ground duty cycle development with the use of a high-fidelity vehicle dynamics simulation model for electrified powertrains. The xEV model uses a mixture of forward (to predict speeds, given torque demands) and inverse dynamics (to predict torques, given constant speed requirements) to predict driveline

Mohamed, Richard, Salvatori, David, Ramakrishnan, Venkat, Magistrali, Stefano

In-Depth Considerations for Electric Vehicle Braking Systems Operation with Steep Elevation Changes and Trailering

2021-01-126310/11/2021

As the automotive industry prepares to roll out an unprecedented range of fully electric propulsion vehicle models over the next few years – it really brings to a head for folks responsible for brakes what used to be the subject of hypothetical musings and are now pivotal questions for system design. How do we really go about designing brakes for electric vehicles? What is really an “optimal’ design for brakes considering the imperatives for the entire vehicle? What are the real “limit conditions” for usage that drive the fundamental design? Are there really electric charging stations planned for or even already existing in high elevations that can affect regenerative brake capacity on the way down? What should be communicated to drivers (if anything) about driving habits for electric vehicles in routes with significant elevation change? The present work attempts to consolidate past published information and combine it with new information and makes a sincere effort to answer these

Antanaitis, David

Application of Brake System Failed State Performance and Reliability Requirements to System Architecting and Control of Autonomous Vehicles

2021-01-126710/11/2021

The modern braking system in the field today may be controlled by over a million lines of computer code and may feature several hundred moving parts. Although modern brake systems generally deliver performance, even with partial failures present in the system, that is well above regulatory minimums, they also have a level of complexity that extends well beyond what the authors of current regulations envisioned. Complexity in the braking system is poised for significant increases as advanced technologies such as self-driving vehicles are introduced, and as multiple systems are linked together to provide vehicle-level “features” to the driver such as deceleration (which can invoke service braking, regenerative braking, use of the parking brake, and engine braking). Rigorous safety-case analysis is critical to bring a new brake system concept to market, but may be too tedious and rely on too many assumptions to be useful in the early architecting stages of new vehicle development. A set

Antanaitis, David, Heil, Edward

Research on Parallel Regenerative Braking Control of the Electric Commercial Vehicle Based on Fuzzy Logic

2021-01-011904/06/2021

Regenerative braking is an effective technology to extend the driving range of electrified vehicles by recovering kinetic energy from braking. This paper focuses on the design of the regenerative braking control strategy for a commercial vehicle which requires significantly larger braking power than passenger cars. To maximize the energy recovery while ensuring the braking efficiency of the vehicle and its braking safety, this paper proposed a fuzzy logic strategy for regenerative braking control, and a feasibility study was conducted for an electric van. The work includes in three steps. Firstly, state variables that significantly affect regenerative braking performance, i.e., vehicle speed, battery State-of-Charge (SOC), and braking intensity, are identified based on mathematical modelling of the vehicle system dynamics in braking maneuver. With the three state variables as control inputs, the fuzzy logic controller is then developed to allocate the required braking force to the

Ye, Meng, Tan, Gangfeng, Lei, Fushou, Chen, Kailang, Feng, Jiaming, Zhao, Feng‘an

Accurate Pressure Control Based on Driver Braking Intention Identification for a Novel Integrated Braking System

2021-01-010004/06/2021

With the development of intelligent and electric vehicles, higher requirements are put forward for the active braking and regenerative braking ability of the braking system. The traditional braking system equipped with vacuum booster has difficulty meeting the demand, therefore it has gradually been replaced by the integrated braking system. In this paper, a novel Integrated Braking System (IBS) is presented, which mainly contains a pedal feel simulator, a permanent magnet synchronous motor (PMSM), a series of transmission mechanisms, and the hydraulic control unit. As an integrative system of mechanics-electronics-hydraulics, the IBS has complex nonlinear characteristics, which challenge the accurate pressure control. Furthermore, it is a completely decoupled braking system, the pedal force doesn’t participate in pressure-building, so it is necessary to precisely identify driver’s braking intention. To improve the control accuracy of the system, this paper proposed a novel pressure

Zhu, Bing, Zhang, Yihan, Zhao, Jian, Chen, Zhicheng, Jin, Wanli

Pressure Tracking Control of Electro-Mechanical Brake Booster System

2020-01-021104/14/2020

The Electro-Mechanical Brake Booster system (EMBB) is a kind of novel braking booster system, which integrates active braking, regenerative braking, and other functions. It usually composes of a servo motor and the transmission mechanism. EMBB can greatly meet the development needs of vehicle intelligentization and electrification. During active braking, EMBB is required to respond quickly to the braking request and track the target pressure accurately. However, due to the highly nonlinearity of the hydraulic system and EMBB, traditional control algorithms especially for PID algorithm do not work well for pressure control. And a large amount of calibration work is required when applying PID algorithms to pressure control in engineering. In this paper, a fuzzy adaptive PI pressure control algorithm based on feed-forward is proposed to a novel self-designed EMBB mechanism, which is utilized to overcome the nonlinear pressure control problem when EMBB is in active braking and improve the

Yang, Weihong, Wu, Jian, He, Rui, Zhu, Bing, Zhao, Jian, Chen, Zhicheng

Integrated Regenerative Braking System and Anti-Lock Braking System for Hybrid Electric Vehicles & Battery Electric Vehicles

2020-01-084604/14/2020

This paper describes development of an integrated regenerative braking system and anti-lock brake system (ABS) control during an ABS event for hybrid and electric vehicles with drivelines containing a single electric motor connected to the axle shaft through an open differential. The control objectives are to recuperate the maximum amount of kinetic energy during an ABS event, and to provide no degraded anti-lock control behavior as seen in vehicles with regenerative braking disabled. The paper first presents a detailed control system analysis to reveal the inherent property of non-zero regenerative braking torque control during ABS event and explain the reason why regenerative braking torque can increase the wheel slip during ABS event with existing regenerative braking control strategies. Then, the regenerative brake control problem during ABS events is formulated with a unified control system architecture where the regenerative braking torque is coordinated with the friction braking

Yao, Yixin, Zhao, Yanan, Yamazaki, Mark

Pressure Tracking Control of Electro-Mechanical Brake Booster System

2020-01-021104/14/2020

Yang, Weihong, Wu, Jian, He, Rui, Zhu, Bing, Zhao, Jian, Chen, Zhicheng

Characterizing Regenerative Coast-Down Deceleration in Tesla Model 3, S and X

2020-01-088304/14/2020

Tesla Motors utilizes a regenerative braking system to increase mileage per charge. The system is designed to convert the vehicles’ kinetic energy during coast down into potential energy by using rotational wheel motion to charge the batteries, resulting in moderate deceleration. During this coast down, the system will activate the brake lights to notify following vehicles of deceleration. In October 2018 Tesla Motors pushed software update 2018.42v9 which increased the regenerative braking force of the Model 3. Previous studies have tabulated regenerative braking performance for Model 3’s but have not addressed recent software changes nor brake light behavior related to regenerative braking. The goal of this paper is to quantify the regenerative braking behavior of Tesla Model 3, S, and X, as well as the timing and activation criteria for the brake lights under a regen/coast-down state. Various Model 3, S, and X of different trim levels (differing by battery size and number of driven

Siddiqui, Omair, Simacek, Daniel, Hoang, Ryan, Famiglietti, Nicholas, Nguyen, Benjamin, Landerville, Jon

INSIDE E-TRON

19AUTP02_0102/01/2019

Insights into the German approach to developing a premium-class EV. Audi has made its ambitious electromobility goals clear, saying it will offer 10 all-electric and 10 plug-in hybrid models by 2025, accounting for at least one-third of its sales. To help achieve this, the company carefully designed the all-new 2019 Audi e-tron luxury SUV to not alienate its core audience. As engineer Anno Mertens, Audi's product manager for electrification put it: “In the end, it's an Audi, it's not an electric car.” Audi's target for the e-tron (yes, the name is all lower case) is the same SUV buyer who might also have shopped for a Q7, Mertens said (the e-tron's wheelbase sits between the Q5 and Q7 in Audi's SUV lineup). To that end, early in the development process, Audi surveyed its customer base to learn just what kind of EV they would use. The questions included how many business trips they take and whether they live in detached homes or in multi-family dwellings.

Blanco, Sebastian

Power Quality Requirements for Plug-In Electric Vehicle Chargers

J2894/1_201901 (Current)01/23/2019

The intent of this document is to develop a recommended practice for PEV chargers, whether on-board or off-board the vehicle, that will enable equipment manufacturers, vehicle manufacturers, electric utilities, and others to make reasonable design decisions regarding power quality. The three main purposes are as follows: 1 To identify those parameters of PEV battery charger that must be controlled in order to preserve the quality of the AC service. 2 To identify those characteristics of the AC service that may significantly impact the performance of the charger. 3 To identify values for power quality, susceptibility, and power control parameters which are based on current U.S. and international standards. These values should be technically feasible and cost effective to implement into PEV battery chargers. SAE J2894/2 will describe the test methods for the parameters/requirements in this document.

Hybrid - EV Committee

Coordinated Control under Transitional Conditions in Hybrid Braking of Electric Vehicle

2018-01-186910/05/2018

In the hybrid brake system of electric vehicle, due to the limitation of the motor braking force when the motor is at high speed and the failure of the regenerative braking force when the motor is at low speed, there are three transitional conditions in hybrid braking: the hydraulic brake system intervenes the braking, the hydraulic brake system withdraws the braking and the regenerative braking force withdraws the braking. Due to the response speed of the hydraulic system is slower than that of the motor, there is a large braking impact (the derivative of braking deceleration) in the transitional conditions of hybrid braking, which deteriorates the smoothness and comfort in braking. Aiming at the impact caused by the poor cooperation between the hydraulic braking force and the motor braking force, a coordinated strategy of double closed-loop feedback and motor force correction is proposed in this paper. The double closed-loop feedback strategy relies on the motor force to compensate

Yu, Zhuoping, Shi, Biaofei, Xiong, Lu, Han, Wei

An Analysis of Braking Behavior in Formula-E® Racing

2017-01-253309/17/2017

As Pure Electric Vehicles have become a recent entrant to the higher end Passenger Vehicle Market, general interest in the overall technology has expanded beyond the environmental interest into the pure performance opportunities associated with electrically driven vehicles. Recently a new Racing Series has formed that is dedicated to Electric Vehicle Racing. Specifically the Formula-E® series has emerged as a venue for competition for Pure Electric open wheel race cars competing on Road Courses throughout the world. Success in the race series is influenced by the available energy that can be stored in the battery along with the applicable electrical efficiencies associated with the drive and control of the Propulsion Motors. The Race series also allows Regenerative Braking. Therefore the performance and ultimate success in the race is additionally influenced by the magnitude and the efficiency of the Regenerative Braking as it is employed by the associated Control System and the

Hall, Thomas J.

Ankle Exoskeleton Aids or Enhances Mobility

TBMG-2539409/01/2016

Clutches can be used to enhance the functionality of springs or actuators in robotic devices. A research team headed up by Steve Collins, an associate professor of mechanical engineering at Carnegie Mellon University, created a lightweight, low-power clutch used to control spring engagement in an ankle exoskeleton.

Research on Electric Vehicle Braking Force Distribution for Maximizing Energy Regeneration

2016-01-167604/05/2016

The driving range of the electric vehicle (EV) greatly restricts the development of EVs. The vehicles waste plenty of energy on account of automobiles frequently braking under the city cycle. The regenerative braking system can convert the braking kinetic energy into the electrical energy and then returns to the battery, so the energy regeneration could prolong theregenerative braking system. According to the characteristics of robustness in regenerative braking, both regenerative braking and friction braking based on fuzzy logic are assigned after the front-rear axle’s braking force is distributed to meet the requirement of braking security and high-efficient braking energy regeneration. Among the model, the vehicle model and the mechanical braking system is built by the CRUISE software. The paper applies the MATLAB/SIMULINK to establish a regenerative braking model, and then selects the UEDC city cycle for model co-simulation analysis. Finally, the feasibility of the proposed control

Liu, Wenchao, Chen, Guoying, Zong, Changfu, Li, Chunshan

Isolated Bidirectional DC Converters for Distributed Battery Energy Applications

TBMG-23242

11/01/2015

Power systems are the core heartbeat of any advanced vehicle. Reliability and flexibility of these systems are of the highest priority. This innovation is a highly efficient and modular isolated bidirectional DC converter for battery energy applications that has been translated into high-priority NASA power system applications, demonstrating transferability, robustness, and scalability.