This paper reviews the development of clean vehicles, including pure electric vehicles (EVs), hybrid electric vehicles (HEVs) and fuel cell electric vehicles (FCEVs), and high energy power batteries, such as nickel metal hydride (Ni-MH), lithium-ion (Li-ion) and proton exchange membrane fuel cells (PEMFCs). The mathematical models and thermal behavior of the batteries are described. Details of various thermal management techniques, especially the PCMs battery thermal management system and the materials thermal conductivity, are discussed and compared. It is concluded that the EVs, HEVs and FCEVs are effective to reduce GHG and pollutants emission and save energy. At stressful and abuse conditions, especially at high discharge rates and at high operating or ambient temperatures, traditional battery thermal energy management systems, such as air and liquid, may be not meeting the requirements. Pulsating heat pipe may be more effective but needs to be well designed. In addition, progress in developing new high temperature material is very difficult. PCM for battery thermal management is a better selection than others. Nevertheless, thermal conductivity of the PCMs such as paraffin is low and some methods are adopted to enhance the heat transfer of the PCMs. The performance and thermo-mechanical behaviors of the improved PCMs in the battery thermal management system need to be investigated experimentally. And the possibility of the heat collection and recycling needs to be discussed in terms of energy saving and efficient.

/pdf/a-review-of-power-battery-thermal-energy-management-qsxgc8m4tk.pdf

A review of power battery thermal energy management

Presents here a complete dynamic model of a lithium ion battery that is suitable for virtual-prototyping of portable battery-powered systems. The model accounts for nonlinear equilibrium potentials, rate- and temperature-dependencies, thermal effects and response to transient power demand. The model is based on publicly available data such as the manufacturers' data sheets. The Sony US18650 is used as an example. The model output agrees both with manufacturer's data and with experimental results. The model can be easily modified to fit data from different batteries and can be extended for wide dynamic ranges of different temperatures and current rates.

Dynamic lithium-ion battery model for system simulation

An electric power tool includes: a brushless motor having a plurality of stator windings and configured to rotate in accordance with voltages applied to the plurality of stator windings, an induced voltage being generated in accordance with a rotation of the brushless motor; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsation voltage having a maximum value larger than the induced voltage and a minimum value smaller than the induced voltage; and an inverter circuit configured to perform switching operations to output the pulsation voltage to the plurality of stator windings by rotation.

Electric power tool

A variety of rechargeable batteries are now available in world markets for powering electric vehicles (EVs). The lithium-ion (Li-ion) battery is considered the best among all battery types and cells because of its superior characteristics and performance. The positive environmental impacts and recycling potential of lithium batteries have influenced the development of new research for improving Li-ion battery technologies. However, the cost reduction, safe operation, and mitigation of negative ecological impacts are now a common concern for advancement. This paper provides a comprehensive study on the state of the art of Li-ion batteries including the fundamentals, structures, and overall performance evaluations of different types of lithium batteries. A study on a battery management system for Li-ion battery storage in EV applications is demonstrated, which includes a cell condition monitoring, charge, and discharge control, states estimation, protection and equalization, temperature control and heat management, battery fault diagnosis, and assessment aimed at enhancing the overall performance of the system. It is observed that the Li-ion batteries are becoming very popular in vehicle applications due to price reductions and lightweight with high power density. However, the management of the charging and discharging processes, CO2 and greenhouse gases emissions, health effects, and recycling and refurbishing processes have still not been resolved satisfactorily. Consequently, this review focuses on the many factors, challenges, and problems and provides recommendations for sustainable battery manufacturing for future EVs. This review will hopefully lead to increasing efforts toward the development of an advanced Li-ion battery in terms of economics, longevity, specific power, energy density, safety, and performance in vehicle applications.

State-of-the-Art and Energy Management System of Lithium-Ion Batteries in Electric Vehicle Applications: Issues and Recommendations

A novel multistage Support Vector Machine based approach for Li ion battery remaining useful life estimation

http://www.dimec.unisa.it/leonardo_new/doc/Use%20of%20lithium-ion%20batteries%20in%20electric%20vehicles.pdf

Use of lithium-ion batteries in electric vehicles

This paper explores the comparative advantages and disadvantages of the simplest form of axial flux geometry, the single sided version, compared to the most common form of radial flux geometry with an inside rotor, when considering permanent magnet synchronous machines. A detailed literature review of comparisons is presented. New material is presented highlighting the benefits of single sided axial flux geometry. The constraints and assumptions made when comparing possibilities are discussed in detail, including a study of the biases these can introduce. The basis of this comparison is founded on constant electromagnetic airgap shear stress, being the product of electric loading and magnetic loading, and indeed the constancy of both of those factors. The metric used for comparison is simply that of the masses of the active materials, steel, copper, and magnet material. Examples are presented, including a machine which recently went into production in quantity. A range of lesser issues which are relevant when one is making a choice, are presented and discussed.

https://ncesr.unl.edu/wordpress/wp-content/uploads/2010/08/105-Patterson-article-Axial-Flux.pdf

A comparison of radial and axial flux structures in electrical machines

The present invention provides a method for controlling the output power of a permanent magnet electric motor (102) using a control means (106). The control means (106) includes a means (134) for measuring motor speed (134) and motor phase current (134), and a means for controlling motor phase current (110) to a desired level. A known relationship between motor phase current and motor torque is then employed by a torque controller so that motor shaft torque can be controlled. A power limiting means (128) then limits the output mechanical power of the motor by dividing a limit value of power by the motor speed to produce a maximum allowable torque setting for that speed.

Method and apparatus for controlling an electric motor

A device for positioning a planar array of magnets within a permanent magnet electrical machine of the type having a rotor and stator with an air gap there between. The device includes a body made of non-ferrous material and having a first side which is attachable to the rotor and a second side which, in an assembled machine, faces the air gap. The first side of the body has a plurality of recesses therein for receiving a corresponding plurality of magnets. The recesses are shaped and arranged to separate the magnets from each other and maintain a consistent spacing between them. When the device is attached to the rotor the magnets are held in a fixed position against the rotor. The electrical machine may be a motor or a generator.

Rotor magnet positioning device

An electric machine is described. The electric machine includes a rotor comprising a rotor disk and a plurality of permanent magnets magnetically coupled to the rotor disk. The plurality of permanent magnets include a substantially flat profile and are aligned in a substantially planar array. The electric machine also includes a stator comprising a solid stator core and a plurality of coils each wound around a coil insulating member. The stator core includes a plurality of stator teeth extending substantially parallel to an axis of rotation of the rotor.

Steven Peter Camilleri

Papers

Use of lithium-ion batteries in electric vehicles

A comparison of radial and axial flux structures in electrical machines

Method and apparatus for controlling an electric motor

Rotor magnet positioning device

Axial flux electric machine and methods of assembling the same