1、 电子与信息工程学院 本科毕业论文 (设计 ) 外 文 文 献 翻 译 译文题目： Design of a Lead-Acid Battery Charging and Protecting IC in Photovoltaic System 学生姓名： 黄祖勋 专 业： 电气工程及其自动化 指导教师： 邓方雄 2012 年 12 月 湖北科技学院本科毕业论文（设计）：外文翻译 1 Design of a Lead-Acid Battery Charging and Protecting IC in Photovoltaic System ZENG De-you,LING Chao-dong,
2、LI Guo-gang (Yuanshun IC Design R&D Center, Huaqiao University, Quanzhou 362021, China) Source: Microelectronic Device&Technology,June 2007 1.Introduction Solar energy as an inexhaustible, inexhaustible source of energy more and more attention. Solar power has become popular in many countries and re
3、gions, solar lighting has also been put into use in many cities in China. As a key part of the solar lighting, battery charging and protection is particularly important. Sealed maintenance-free lead-acid battery has a sealed, leak-free, pollution-free, maintenance-free, low-cost, reliable power supp
4、ly during the entire life of the battery voltage is stable and no maintenance, the need for uninterrupted for the various types of has wide application in power electronic equipment, and portable instrumentation. Appropriate float voltage, in normal use (to prevent over-discharge, overcharge, over-c
5、urrent), maintenance-free lead-acid battery float life of up to 12 16 years float voltage deviation of 5% shorten the life of 1/2. Thus, the charge has a major impact on this type of battery life. Photovoltaic, battery does not need regular maintenance, the correct charge and reasonable protection,
6、can effectively extend battery life. Charging and protection IC is the separation of the occupied area and the peripheral circuit complexity. Currently, the market has not yet real, charged with the protection function is integrated on a single chip. For this problem, design a set of battery chargin
7、g and protection functions in one IC is very necessary. 2.System design and considerations The system mainly includes two parts: the battery charger module and the protection module. Of great significance for the battery as standby power use of the occasion, It can ensure that the external power sup
8、ply to the battery-powered, but also in the battery overcharge, over-current and an external power supply is disconnected the battery is to put the state to provide protection, the charge and protection rolled into one to make the circuit to simplify and reduce valuable product waste of resources. F
9、igure 1 is a specific application of this Ic in the photovoltaic power generation system, but also the source of this design. 湖北科技学院本科毕业论文（设计）：外文翻译 2 Figure1 Photovoltaic circuit system block diagram Maintenance-free lead-acid battery life is usually the cycle life and float life factors affecting t
10、he life of the battery charge rate, discharge rate, and float voltage. Some manufacturers said that if the overcharge protection circuit, the charging rate can be achieved even more than 2C (C is the rated capacity of the battery), battery manufacturers recommend charging rate of C/20 C/3. Battery v
11、oltage and temperature, the temperature is increased by 1 C, single cell battery voltage drops 4 mV, negative temperature coefficient of -4 mV / C means that the battery float voltage. Ordinary charger for the best working condition at 25 C； charge less than the ambient temperature of 0 C； at 45 C m
12、ay shorten the battery life due to severe overcharge. To make the battery to extend the working life, have a certain understanding and analysis of the working status of the battery, in order to achieve the purpose of protection of the battery. Battery, there are four states: normal state, over-curre
13、nt state over the state of charge, over discharge state. However, due to the impact of the different discharge current over-capacity and lifetime of the battery is not the same, so the battery over discharge current detection should be treated separately. When the battery is charging the state a lon
14、g time, would severely reduce the capacity of the battery and shorten battery life. When the battery is the time of discharge status exceeds the allotted time, the battery, the battery voltage is too low may not be able to recharge, making the battery life is lower. Based on the above, the charge on
15、 the life of maintenance-free lead-acid batteries have a significant impact, while the battery is always in good working condition, battery protection circuit must be able to detect the normal working condition of the battery and make the action the battery can never normal working state back to nor
16、mal operation, in order to achieve the protection of the battery. 3.Units modular design 3.1The charging module Chip, charging module block diagram shown in Figure 2. The circuitry includes current limiting, current sensing comparator, reference voltage source, under-voltage solar battery array Charge controller controller Discharge controller DC load accumulator
