Search

For high-power applications such as electric motorcycles, batteries in series to provide the required voltage is fairly common. The 48V is 12V connected four cells in series for lead-acid batteries of electric motorcycles. After charging and discharging of lead-acid batteries several times, the voltages are often imbalance. Without proper protection, may cause an excessive discharge of lead-acid batteries for early damage. Therefore, lead-acid battery module requires a simple balance circuit to improve battery life in order to avoid over-voltage or under-voltage condition occurs. Energy balance circuit to improve lead-acid battery module matching problems, make the safety and cycle life of lead-acid batteries to improve. This research intends to complete balanced circuit design of lead-acid batteries.

Pure lithium-ion batteries for electric vehicles in the course of the temperature rise, not only directly affect the performance and life of the battery, there is a potential safety hazard. In this paper, a pure electric vehicle with a lithium-ion battery pack with no heatsink, through testing and without thermal simulations with a model feasibility analysis.

With the wide application of electric vehicles, the battery fast charging has become a subject of research. In this paper, how to quickly charge the battery and prolong the life of the battery are described. By analyzing all kinds of storage battery charging method, I have summarized a fast charging technology based on fuzzy control, this method can quickly charge the batteries, and can prolong the life of the battery.

In operating of a flow battery, a certain flow rate should be maintained in order to guarantee its performance. But the pump consumed power may cause significant losses for the overall battery system. In this paper, a fresh electrical model is proposed for the novel single flow zinc-nickel battery. The model consists of both battery stack part and pump power part, which consequently not only predicts accurately the battery electrical output, but also estimates the pump consumed power at different electrolyte flow rate. Based on the validated model, the influence of pump power on flow battery’s system efficiency can be evaluated at different operating modes. At last, possible means to further improve the system efficiency of battery is discussed.

A hybrid mobile power supply is developed based on air-cooled Proton Exchange Membrane Fuel Cell (PEMFC) and lithium battery. Pure fuel cell provides a rated output of 25W. With the assistance of lithium battery, the system provides instantaneous power of 50W. The system consists of fuel cell and its controller, lithium battery and its management circuit, power switching circuit, system control circuit and DC/DC convert circuit. The system is designed and realized, the measurement results show that the system works steadily below 50W.

In order to meet the demand of power supply voltage and capacity, power battery usually uses multiple single cells in series. Due to that performance difference will be increased in the process of charging and discharging, eventually it leads to a sharp drop in battery performance and shorten the cycle life. By analyzing the causes of battery failure in advance, the design is based on the energy storage the inductance of the non dissipative equalization circuit. According to the different status of a single cell in the battery pack, the fuzzy control algorithm can fine-tuning the charging current of single battery through balanced circuit, so as to realize rapid equalization charging of the battery pack. This paper makes a comparison with the charging simulation experiment by using charging model of four batteries in series. Experimental results show that the imbalance between the battery pack can cause damage to the battery and cannot make each battery charged in. The designed balance circuit and fuzzy equilibrium controller designed can realize lossless transfer of energy to reduce the inconsistency of each single cell and achieve the requirement of the equalizing charge.

The project is innovative to convert vibration energy of low grade to high grade of electricity, achieved the purpose of saving energy and battery recycling. The built-in permanent magnet generator inside the battery can recharging the battery and external power supply when vibrating both took advantage of the vibration energy and ensure the reliable energy source of the battery. So it has great market prospect.

The author puts forward the core system design scheme of kilowatt aluminum-air battery on the basis of its chemistry characteristics and calculated function parameters of cell stack, and introduces the component functions, including control design, functional electrolyte circulation, air transport, DC / AC inverter system and other modules.

This paper presents the charging process procedure of Li-ion Battery pack for electric vehicle, which is implemented based on constant current and constant voltage (CC-CV) mode. All the informations regarding battery voltage level, state of charge (SOC) during charging and discharging processes, and battery temperature, is displayed on computer via battery management system (BMS). During the charging process, the BMS monitors the voltage balancing in Li-ion battery pack, as well as the cells voltage in each modules. The voltage difference between the highest voltage cell and the lowest voltage cell is very small, which validates the voltage stability and balance in battery pack during the charging and discharging processes.

Li-ion battery, as a new type of energy storage equipment, has small size, large power density, high individual voltage, low rate of self-discharging and small self-resistance etc. It substitutes the traditional power battery in AGV.In practical process, due to the difference of battery cells, after a period of charge-discharge time, the upper and lower voltage limits of every unit of batteries become various, seriously affecting the system performance. The idea of upper and lower equalizer is released for this case. Then, a further research is made on the equalizer circuit of li-ion battery. The experiment result proves the correctness of design on several types of lithium battery equalizer circuit.

This study proposes a solution to the problems with electric vehicles, which are characterized by short driving range and long time for charging. The battery fast-swap system we studied includes generality power battery, locking system and auto battery pack fast-swap equipment, which only takes owners about four minutes to finish a completed auto power battery swap procedure. At the same time, we use virtual prototyping software hyperworks to evaluate the strength and stiffness of the structure of the battery fast-swap system, all parameters above can meet requirement of mechanical property for electric vehicles. Moreover, we propose a novel business model of “naked car sales-battery lease-battery swap”, which can improve the problem of energy supply in electric vehicle. Particularly, it has a certain significance to perfect the building of charging/battery swap infrastructure standard system.

This paper expounds the principle of lead-acid battery intelligent charging system, design the main circuit of the intelligent charging system, the positive and negative pulse charging circuit, control circuit and software design of intelligent charging system. Experimental results show that the system USES intelligent charging method can effectively improve the charging efficiency of battery and prolong the service life of the battery, can be widely used in lead-acid battery charging system, which has a broad prospect of industrialization and social benefits.

The more popular of electric vehicles is, the higher the load capacity of the battery is in the power system, therefore, the charging and discharging technology is particularly important. This paper introduces several electric vehicle battery charging methods commonly used at present, describes working principle of the bidirectional DC/DC converter in detail in the battery charging and discharging process, and the bidirectional DC/DC charging and discharging control strategy. Finally, the electric vehicle battery charging and discharging simulation model is built, the validity of the electric vehicle battery charging and discharging model is verified based on control strategies mentioned herein by use of simulation.

The high-capacity lithium batteries are optimization in coal mine backup power supply. Their electricity properties directly affect their related equipment performance. So it is crucial importance for controlling lithium battery charge and discharge and understanding their characteristics. It puts forward design scheme of lithium-ion battery charging and discharging controller with STM32F103 chip. It includes DC/DC adopting full bridge phase shift high power switch, the sampling and processing circuit of voltage, current and temperature, charge and discharge control circuit, and software design flow of the real-time monitoring of lithium-ion batteries. The test shows that the charging and discharging control meet the design requirements.

Electric vehicle power battery is one of the key technologies for electric vehicle charging and discharging. This paper summarized the characteristics of lithium iron phosphate battery firstly, then adopted intermittent discharge method to get the battery OCV-SOC curve under experimental tests, determined the parameters of OCV-SOC models, analyzed the advantages and disadvantages of commonly used cell performance model, finally built electric vehicle battery charging model.

Power battery pack under high-rate discharge conditions produces thermal aggregation phenomena. Generated heat during charging and discharging that distributes in battery pack affects performance of battery and so that shortens its life. So the battery pack thermal management is necessary to electric vehicles. In this paper, an ideal thermal management solution is put forward with a battery pack temperature equilibrium approach and a battery pack overall thermal dissipation structure by finite element analysis. Theoretical analysis result shows that the thermal management solution can effectively cool the battery pack to the ideal working temperature range 25~40°C and improve the battery pack temperature uniformity with the maximum temperature difference which is below 5°C, which enhance the cycle life of power battery pack for electric vehicle applications.

In the charge and discharge system of lead-acid battery, in order to ensure the normal operation of charge and discharge, and to prolong the service life of lead-acid battery, battery management system (BMS) must be built up for lead-acid battery. The battery management system detects each index of battery to prevent over charge and over discharge appeared. In this paper, the function of battery management system, detection of battery voltage and battery current are researched. The lead-acid battery management system is designed to achieve the purpose of real-time monitoring of the lead-acid battery.

This paper designed a large-capacity Li-ion battery formation system, and illustrated its composition and working principle. The formation system uses a programmable voltage-limiting and constant-current control circuit with voltage-limiting protection function to prevent Li-ion battery over-charge and over-discharge. The system consists of a upper computer (server) and a number of lower computers (formation units) linked with 485 bus. The server can monitor formation process and record formation data in real-time. By testing, the system has good characteristics, such as large charge and discharge current, high control accuracy, multiple-step programming, etc., and it can meet the needs of a large-scale power Li-ion battery formation.

A promising applied technology on hybrid power system for electric vehicle was proposed in this paper. Considring the actual bus working conditions, a testing system of multi-stage pulse discharge was designed. The separated LiFePO4series, lead-acid battery and the paralleled battery pack, constituted by the lithium battery and lead-acid battery with equal capacity, were tested to compare the voltage and power characteristics, as well as temperature rise. The results indicate that the lithium-ion batteries provide momentary high currant at high rate pulse discharge while keeping the lead-acid stay at a higher state of charge and improving its cycle life. During the intermittent, spontaneous capacity redistribution is achieved in the paralleled system, which helps to relieve the potential polarization and avoid the over-discharge of lithium-ion battery. Systematic analysis of the paralleled system demonstrats that it is benefitial to the circuit control, cost, cycle life and safety.

Battery charging is the most substantial issue in battery management systems, and the intelligent charger can provide stable and reliable energy conversion to electric vehicles. So the research of high power intelligent battery charger becomes very important. This paper introduces the main concept of battery charging of an electric vehicle, and studies the working principle and hardware scheme of an intelligent charging system, and researches the material performance. And based on research results, we will propose desirable characteristics of charger for public use.

With the development of clean energy, lithium battery is paid more and more attention because of its outstanding energy storage characteristics .So the novel bi-directional lithium battery charger topology is presented in this paper and operating theory is analyzed clearly. It can make the energy bi-directional flow between the power grid and battery as needed. And it can also fully adapt to the lithium battery charging and discharging characteristics. Based on phase shifting control, the output voltage ripple and the inductor current ripple can be reduced in the condition of the same input and output, and the DC bus voltage can also be improved. This bi-directional lithium battery charger topology can be widely used in battery energy storage system.

Introducing the concept of Battery Electric Vehicle developed at the Technical University of Liberec, intended for test and educational purposes. It is a lightweight four wheeled vehicle with an open frame primarily designed for ease of access to all major vehicle components. For the main structural elements of the vehicle frame was chosen modular system of extruded aluminum profiles. The vehicle power unit consists of BLDC motor paired with multi-speed manual transmission. Traction battery with regard for the electrical safety consists of 17s LFP cells only, resulting in a nominal voltage of 55 VDC (63 VDC fully charged). Total amount of energy stored in the traction battery is 10.8 kWh.

In order to satisfy the test demand of Electric Vehicle batteries, after the analysis of the existing battery test systems, aiming at the problems of them, an EV battery test platform with high degree of simulation is designed, based on the upper and lower computer structure. The PC software is compiled, which could control the battery to discharge with constant current or constant power, or to simulate the real road status, by the communication with the lower computer through CAN bus and 485 bus. The corresponding control method to realize the discharging test with constant current is designed, also an interface to Excel which can read the configure information from Excel to realize the simulation of discharging test is designed. Several battery packs test are completed.

Based on the current situation and development trend of domestic electric commercial vehicle, we research the mode and the key technology of battery quick change, analyze and compare the three common mode, then put forward a half automatic electric mode which is low cost and high flexibility, accordingly, it can adapt to the current electric car battery quick change development requirements, thus to provide a reference for battery quick change station infrastructure construction planning, and to provide the foundation to improve the battery quick change technology.

The amount and the power of the electrical appliances on cars are increasing, and the fuel consumption produced by the electrical system is getting larger. To design an automotive electrical power system with higher efficiency is a very practical requirement. In this paper, we proposed an automotive intelligent alternator control system. In this system, we divided the battery states to different partitions by state of charge, and designed an intelligent alternator control system to work in different mode according to the battery partition and the vehicle state. With this system we can realize the braking energy regeneration for traditional cars and reduced the fuel consumption. We carried out the experiment with a car, and the results indicated that with this system, the fuel consumption can be reduced by about 2-3%.

In this paper, the main performances of the lead-acid battery used on in a real off-road vehicle were tested through experiments. The lead-acid battery voltage and current characteristic curves of the self-discharge, real vehicle starting experiment and battery electricity demand experiment performance in the different conditions were studied. The results show that this lead-acid battery can be used as the preferred battery and the charging and discharging rules of this battery can be used to improve the vehicle design.

The charger for the electric vehicle (EV) is a nonlinear device, and will cause harmonic pollution when put into operation. This paper, firstly, analyzes harmonic caused by charger theoretically and defines its equivalent model as a three-phase full-bridge controlled rectifier, getting the characteristics of charger through the Fourier analysis of the switching function. Secondly, this paper builds the simulation model of the charger using Matlab/Simulink and replaces the car battery with a nonlinear resistor with resistance value changing over time. The parameters in the simulation model are the same as the charging stations in use and the results verify the charger’s harmonic characteristics. Finally, compared with the measured data, the results show the simulation model is suitable for engineering calculations.

The development of lithium-ion battery technology bring new energy supply, because of the characteristics of new energy vehicles with light weight, large capacity, and can be recharged, so as a new energy supply for new energy vehicles, at present, there are still some technical constraints widely used in lithium-ion battery, the current some car battery companies have started to address the technical bottleneck of the lithium-ion battery and lithium-ion battery will become an important energy source of new energy vehicles.

According to the requirements of the battery pack on pure electric vehicles, designed a distributed battery management system using the bus communication technology, the system can detect various operating parameters of the battery in real-time, diagnose and alarm according to the battery status. The system can also share information with the other systems of the vehicle through CAN bus. Through testing the system, the result shows that it can accurately measure the current and voltage of the battery, and the measurement accuracy meets the actual requirements.

Stainless automotive battery fastener requires high dimension precision and narrow tolerance. In order to save the developing cost and accumulate more production design experiences, CAD/CAE technology has been used in multi-stage cold forging with five stages to shorten our developing cycle time. In this paper, the CAD drawing is made by Inventor 3D software, then import the STL file to DEFORM-3D software to do the settings of pre-process and simulation analysis. Effective stress, effective strain, velocity field, and forging force have been shown in this study. Finally, the actual manufacture measurement results compares with simulation datum to verify the analysis acceptance. After comparing the FEM simulation results with actual forming measurements, the error rate of washer diameter is increased in fourth stage. Although the measurement results are still in tolerance, the future work is to decrease the error rate through optimizing the mold design of fourth stage. The verification is performed to reduce the error rate according to the research method proposed in the study. On the other hand, the mold life in the actual forming is found to be easily damaged in the fifth stage. In the future, production improvement should be done through modifying the design of mold and die for the third and the fourth stages, the life of mold and die is explored to reduce the forging force in the fifth stage.

As a new type of energy of large-capacity and high-power, li-ion power battery is widely used in many fields such as energy storage, uninterruptible power system, mobile communications, electric toys, etc. At present, traditional human-based detection methods are mainly adopted in the detection process of battery formation, which to some extent exerts pressure on the cost of human resources and management of lithium battery enterprise. In order to solve this problem, this paper puts forward an elevator scheme applied to formation detection line. The elevator is used to control the battery pack’s movement in the vertical direction and the horizontal direction. The scheme reduces the labor intensity of detection work in the production line. The elevator system has been applied to formation detection lines now, and achieved good economic benefits.

Basing on the status quo of the development of electric vehicle and electric vehicle’s Charging/battery swap infrastructure, Discussion and analysis is made with focus on the battery swap mode and it’s practising method of electric passenger car. According to the body structure of different types of electric passenger car and the Situation that the battery pack is equipped with, Electric passenger car are divided into two types: chassis battery type and battery rear-equipped type. Respectively, analyzed the battery swap mode for the two types of electric passenger cars; And two feasible battery swap projects are advanced , analysed and compared.Then pointed out the difficulties and problems with the construction of the battery swap station for electric passenger car; Finally, suggestions and methods to solve the problems were offered.

After discussing the charging and discharging characteristics of valve regulated lead acid(VRLA) battery, we described the working principle of UC3906. Then designed the controller of 12V battery charge circuit, 12V battery discharge protection circuit and lamp detection control circuit. This controller achieved automatic switch of lighting system, it could efficiently charge the battery and avoid over-charge or over-discharge. The result showed that this controller extend the life of the battery.

Lithium-ion batteries have more excellent performance than other types of batteries, thus it is widely used in electric vehicles. Using batteries as the main power supplier does inevitably generate a lot of heat which not only deteriorates the batteries, but endangers the safety of the vehicle. In this paper, the temperature distribution of the batteries in the pure electric vehicles was investigated to minimize the heat generated in the batteries. The finite element formulations of the 3-D heat conduction equation of the battery were established for both steady and transient states. Then the finite element simulations were developed to investigate and optimize the temperature distribution of the battery and the battery pack. A parametric study was completed such that the heat generated in the battery pack can be minimized.

Li-ion power battery which has a broad prospect of application in many industry fields is a new type of high power battery. The formation is a key process in battery manufacture. After formation, the active materials of anode and cathode in the battery can be activated. Consequently, the charge-discharge performance, self-discharge performance, reserve performance and some other comprehensive performances can be improved. Only after formation can batteries achieve the best performance. With the change of formation process, the formation and holding for a single battery has been changed to for a group. Therefor, a new type of battery parameter testing equipment needs to be designed, which can test a group of batteries automatically. This paper will introduce the design of this equipment thoroughly.

The electricity changing models for the energy supply of electric vehicles are described and introduced. A more suitable method of fast replacing battery of electric vehicles is found and the practical method and process of quickly replacing battery are focused as a major topic. The changing equipment used is studied and described while the efficiency of electrical changing equipments is discussed. The reserve number of batteries in power charging plant and the number of vehicles that each quickly changing device could service are studied and derived.