| With the continuous expansion of the scale of Chinese City,the area of private transport in the rapid growth of car demand is more and more large and medium-sized city to limit the traffic capacity, electric motorcycle to operate fast, easy stop, no pollution, and the price is relatively cheap, as a means of transportation for the actual needs of the most close to the. The inventory is huge. Literature research shows: the current electric motorcycle market has short battery life, battery SOC estimation error, continued driving mileage is not true, the main reason is that the battery pack is not detailed in the long-term management system, overcharge and over discharge state, resulting in the rapid decline in performance of battery or battery failure scrap. Therefore, the design of a battery management system for electric motorcycle a suitable for China’s electric motorcycle market of great significance.In order to solve the above problems, this paper puts forward a kind of battery management system for the power supply of the electric motorcycle. The lead acid battery pack is composed of 4 12 V lead acid battery, which is controlled by a single chip microcomputer. Data acquisition circuit, protection circuit. Display circuit. Storage circuit. Alarm circuit, the main research contents are as follows:(1)For single battery of inconsistency affect battery life problems, this paper by studying the common equalization charging ways, presents a balanced mode switching method of parallel "balanced" way based on series and parallel. This way the series battery group to realize the parallel charging, discharging in series, to achieve a balance between single cells, inhibit the battery "bucket effect", is most suitable for the electric motorcycle has the advantages of compact structure, low cost of design principle of a balanced approach.(2)For electric motorcycle batteries continued driving mileage is not true, the remaining power error problem, in this paper, through the study of the common residual capacity estimation method, the open circuit voltage method and ampere hour method, taking into account lead-acid battery capacity influence factors, the remaining power correction, reduce the prediction error, to achieve accurate estimation.(3)In the aspect of hardware design, the system uses a microcontroller as the main controller, and selecting the current detecting chip and other low cost high performance components to complete the system design, the main control battery charging at the optimum charging rules, to complete the accurate detection of voltage, current and temperature, and design a reliable protection and fault alarm system; the system is connected to PC by bus, easy to achieve real-time information transmission and feedback.(4)In the aspect of software design, the system design of the main controller program and the main modules of the program design. Because the system used on and automatically convert circuit and current detecting chip, regardless of the battery group in series or in parallel can real-time detection to the state of each single battery, and stored in memory, so through the analysis of the battery status can complete each single battery life prediction.(5)For the electric motorcycle battery management system was designed and many experiments, and data analysis. The simulation results show that the successful implementation of the system function. Test results show that the battery management system designed in this paper can well realize battery management system voltage detection, current detection, temperature detection, calculation, battery overcharge protection, under voltage protection and current protection, the high temperature alarm function, meet the design requirements. |
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