A review on the key issues for lithium-ion battery management in electric vehicles

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

The objective of this paper is to propose a new inverter topology for a multilevel voltage output. This topology is designed based on a switched capacitor (SC) technique, and the number of output levels is determined by the number of SC cells. Only one dc voltage source is needed, and the problem of capacitor voltage balancing is avoided as well. This structure is not only very simple and easy to be extended to a higher level, but also its gate driver circuits are simplified because the number of active switches is reduced. The operational principle of this inverter and the targeted modulation strategies are presented, and power losses are investigated. Finally, the performance of the proposed multilevel inverter is evaluated with the experimental results of an 11-level prototype inverter.

A step-up switched-capacitor multilevel inverter with self-voltage balancing

This paper presents an online method for the estimation of the state of health (SOH) of valve-regulated lead acid (VRLA) batteries. The proposed method is based on the state of charge (SOC) of the battery. The SOC is estimated using the extended Kalman filter and a neural-network model of the battery. Then, the SOH is estimated online based on the relationship between the SOC and the battery open-circuit voltage using fuzzy logic and the recursive least squares method. To obtain the open-circuit voltage while the battery is operating, the reflective charging process is employed. Experimental results show good estimation of the SOH of VRLA batteries.

Online State-of-Health Estimation of VRLA Batteries Using State of Charge

Summary
Estimating the dynamic status parameters of a battery, such as its state of health (SoH) and remaining useful life (RUL), is still a very difficult and complex task. In this paper we perform a structured review of the most relevant state of the art models, algorithms and commercial devices employed in the estimation of the SoH/RUL battery performance figures, in the context of embedded applications. The models and estimation techniques are thoroughly classified and, for each taxonomy class, a presentation of the working principles is made. A comprehensive set of metrics is then introduced for the evaluation of the SoH/RUL estimation techniques from the perspective of their implementation and operation efficiency in embedded systems. These algorithms are then analyzed and discussed in a comparative manner, with concrete figures and results. The capability and the performance of the different types of off-the-shelf fuel gauges to estimate the battery SoH/RUL parameters are also evaluated in this paper. Copyright © 2016 John Wiley & Sons, Ltd.

Battery state of health estimation: a structured review of models, methods and commercial devices

Determining the start and end of the voltage sag event is very important for sag analysis and mitigation. There are several detection methods for voltage sags in which sag voltages are usually expressed in the terms of RMS. The RMS method represents one cycle historical average value, not instantaneous value which may lead to long detection time when voltage sag has occurred. This paper will proposed a novel voltage sag detection method based on miss voltage technique. Proper dead-band and hysteresis are used in the method. The actual instantaneous voltage is compared with certain percentage of desired grid voltage and certain percentage of the amplitude of the grid voltage. Through instantaneous value comparison, low instantaneous value of the grid is shielded which overcome the mishandling turnover of voltage sags. The approach is fully described, and the results are compared with other methods for marking the beginning and end of sag, such as RMS value evaluation method and Peak-value method and simulation result provides that the method is efficient and fast and can be used to determine the initiation and recovery of voltage sags accompanied by missing voltage technique.

/pdf/a-novel-detection-method-for-voltage-sags-4zqn7be5dm.pdf

A Novel Detection Method for Voltage Sags

Battery management system (BMS) is an integral part of any electrical vehicle, which ensures that the batteries are not subjected to conditions outside their specified safe operating conditions. Thus the safety of the battery as well as of the passengers depend on the design of the BMS. In the present work a preliminary work is carried out to simulate a typical BMS for hybrid electrical vehicle. The various functional blocks of the BMS are implemented in SIMULINK toolbox of MATLAB. The BMS proposed is equipped with a battery model in which SOC is used as one of the states to overcome the limitation of stand-alone coulomb counting method for SOC estimation. The parameters of the battery are extracted from experimental results and incorporated in the model. The simulation results are validated by experimental results.

/pdf/battery-management-system-and-control-strategy-for-hybrid-4842836e94.pdf

Battery management system and control strategy for hybrid and electric vehicle

High-intensity discharge (HID) lamps are becoming popular substitutes for halogen lamps in automotive headlamps because of the high lumen/watt ratio and the color of the light. In this paper, a ballast (integrated with a voltage multiplier circuit in the secondary winding of the dc converter transformer) with dimming control is presented. The proposed circuit not only eliminates one auxiliary winding but also reduces the voltage across the switch on the primary side and consequently permits the selection of switches with a lower rating. A brief review of the HID circuits is done and compared with the proposed circuit. Experimental results from the prototype are presented. This paper also presents different methods of dimming the automotive HID lamps based on analog and digital control and discusses the relative merits of each of the methods. The dimming control is implemented using both the methods, and experimental results are presented. It is envisaged that the dimming control will provide some flexibility to drivers in the control of HID lamps to suit the driving conditions in the modern cities that are very well lit at night. This paper investigates the merits of each method and discusses the practical issues for implementing such controls.

/pdf/implementation-of-a-voltage-multiplier-integrated-hid-4au97rz30i.pdf

Implementation of a Voltage Multiplier Integrated HID Ballast Circuit With Dimming Control for Automotive Application

A system for automatically controlling power supply to a lamp ( 101 ) of a vehicle, the system comprising: a detection module ( 20 ) to detect whether the vehicle is stationary or non-stationary; a controller ( 102 ) to receive a signal ( 25 ) having a first value transmitted by the detection module ( 20 ) when the vehicle is detected as stationary, and the controller ( 102 ) to receive a signal ( 25 ) having a second value transmitted by the detection module ( 20 ) when the vehicle is detected as non-stationary, wherein if the signal ( 20 ) having the first value is received by the controller ( 102 ), the controller ( 102 ) reduces the power supply to the lamp ( 101 ) from a first power level to a lower second power level in order to reduce energy consumption of the lamp ( 101 ), and if the signal ( 25 ) having the second value is received by the controller ( 102 ), the controller ( 102 ) restores the power supply to the lamp ( 101 ) from the lower second power level to the first power level.

Method and system for automatically controlling power supply to a lamp of a vehicle

The exigencies created by the shortage of energy supplies and the ever-growing air pollution stress the need for an alternative solution to the on-board power generation. The purpose of this paper is to develop a novel switched reluctance wind power generator (SRWPG) system for electric vehicles (EVs), which can convert the wind power into electric power so as to charge a battery or support other vital loads in an EV on-board. The work will focus on collecting valuable first hand experience in the wind assisted on-board power generation system. Various configurations of the wind turbines are studied and the one suitable to the project is proposed in the investigation. In addition to the mechanical aspect of the SRWPG system due attention is given to the control aspect of the system according to the characteristics of switched reluctance generators (SRGs).

/pdf/research-on-a-novel-switched-reluctance-wind-power-generator-32upfnan0f.pdf

B.P. Divakar

Papers

A Novel Detection Method for Voltage Sags

Battery management system and control strategy for hybrid and electric vehicle

Implementation of a Voltage Multiplier Integrated HID Ballast Circuit With Dimming Control for Automotive Application

Method and system for automatically controlling power supply to a lamp of a vehicle

Research on a novel switched reluctance wind power generator system for electric vehicles