外文翻译光伏系统中蓄电池的充电保护ic电路设计大学本科毕业论文.doc

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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： 专 业： 电气工程及其自动化 指导教师： 2012年12月 湖北科技学院本科毕业论文（设计）：外文翻译Design of a Lead-Acid Battery Charging and Protecting IC in Photovoltaic System1.IntroductionSolar energy as an inexhaustible,

2、 inexhaustible source of energy more and more attention. Solar power has become popular in many countries and regions, 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

3、-free lead-acid battery has a sealed, leak-free, pollution-free, maintenance-free, low-cost, reliable power supply 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 p

4、ortable instrumentation. Appropriate float voltage, in normal use (to prevent over-discharge, overcharge, over-current), 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 batte

5、ry life. Photovoltaic, battery does not need regular maintenance, the correct charge and reasonable protection, 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, charge

6、d with the protection function is integrated on a single chip. For this problem, design a set of battery charging and protection functions in one IC is very necessary.2.System design and considerationsThe system mainly includes two parts: the battery charger module and the protection module. Of grea

7、t significance for the battery as standby power use of the occasion, It can ensure that the external power supply 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 an

8、d protection rolled into one to make the circuit to simplify and reduce valuable product waste of resources. Figure 1 is a specific application of this Ic in the photovoltaic power generation system, but also the source of this design.accumulatorDC loadcontroller Discharge controllerChargecontroller

9、solar battery arrayFigure1 Photovoltaic circuit system block diagram Maintenance-free lead-acid battery life is usually the cycle life and float life factors affecting the life of the battery charge rate, discharge rate, and float voltage. Some manufacturers said that if the overcharge protection ci

10、rcuit, 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 voltage and temperature, the temperature is increased by 1 C, single cell battery voltage drops 4 mV, negative temperature coefficie

11、nt 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 may shorten the battery life due to severe overcharge. To make the battery to extend the working life, have a certain understanding

12、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-current state over the state of charge, over discharge state. However, due to the impact of the different discharge current over-capacit

13、y 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 long time, would severely reduce the capacity of the battery and shorten battery life. When the battery is the time of discharge statu

14、s 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 the life of maintenance-free lead-acid batteries have a significant impact, while the battery is always in good working condition,

15、 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 normal operation, in order to achieve the protection of the battery.3.Units modular design 3.1The charging moduleChip, charging module

16、 block diagram shown in Figure 2. The circuitry includes current limiting, current sensing comparator, reference voltage source, under-voltage detection circuit, voltage sampling circuit and logic control circuit.Voltage sampling comparatorUndervoltage detection circuitR- powerVoltage amplifierPower

17、 indicatorLimiting amplifierCurrent samplingcomparatorLogical moduleCharging indicatorState level controlStart amplifierdriverFigure2 Charging module block diagram The module contains a stand-alone limiting amplifier and voltage control circuit, it can control off-chip drive, 20 30 mA, provided by t

18、he drive output current can directly drive an external series of adjustment tube, so as to adjust the charger output voltage and current . Voltage and current detection comparator detects the battery charge status, and control the state of the input signal of the logic circuit. When the battery volt

19、age or current is too low, the charge to start the comparator control the charging. Appliances into the trickle charge state when the cut-off of the drive, the comparator can output about 20 mA into the trickle charge current. Thus, when the battery short-circuit or reverse, the charger can only cha

20、rge a small current, to avoid damage to the battery charging current is too large. This module constitutes a charging circuit charging process is divided into two charging status: high-current constant-current charge state, high-voltage charge status and low-voltage constant voltage floating state.

21、The charging process from the constant current charging status, the constant charging current of the charger output in this state. And the charger continuously monitors the voltage across the battery pack, the battery power has been restored to 70% to 90% of the released capacity when the battery vo

22、ltage reaches the switching voltage to charge conversion voltage Vsam charger moves to the state of charge. In this state, the charger output voltage is increased to overcharge pressure Voc is due to the charger output voltage remains constant, so the charging current is a continuous decline. Curren

23、t down to charge and suspend the current Ioct, the battery capacity has reached 100% of rated capacity, the charger output voltage drops to a lower float voltage VF. 3.2 Protection ModuleChip block diagram of the internal protection circuit shown in Figure 3. The circuit includes control logic circu

24、it, sampling circuit, overcharge detection circuit, over-discharge detection comparator, overcurrent detection comparator, load short-circuit detection circuit, level-shifting circuit and reference circuit (BGR).Over-current detection comparator2Load short detection circuitOver-current detection cir

25、cuitOver-current detection comparator1Overcharge detection comparatorLevel conversioncircuitControl logic circuitOver dischargedetection comparatorSampling circuitFigure3 Block diagram of battery protectionThis module constitutes a protection circuit shown in Figure 4. Under the chip supply voltage

26、within the normal scope of work, and the VM pin voltage at the overcurrent detection voltage, the battery is in normal operation, the charge and discharge control of the chip high power end of the CO and DO are level, when the chip is in normal working mode. Larger when the battery discharge current

27、 will cause voltage rise of the VM pin at the VM pin voltage at above the current detection voltage Viov, then the battery is the current status, if this state to maintain the tiov overcurrent delay time, the chip ban on battery discharge, then the charge to control the end of CO is high, the discha

28、rge control side DO is low, the chip is in the current mode, general in order to play on the battery safer and more reasonable protection, the chip will battery over-discharge current to take over the discharge current delay time protection. The general rule is that the over-discharge current is lar

29、ger, over the shorter the discharge current delay time. Above Overcharge detection voltage, the chip supply voltage (Vdd Vcu), the battery is in overcharge state, this state is to maintain the corresponding overcharge delay time tcu chip will be prohibited from charging the battery, then discharge c

30、ontrol end DO is high, and charging control terminal CO is low, the chip is in charging mode. When the supply voltage of the chip under the overdischarge detection voltage (Vdd R2, the partial pressure of the output voltage, the formation of the undervoltage positive feedback. Output, undervoltage l

31、ockout, and plays a protective role.5. Simulation results and analysisThe design of the circuit in CSMC 0.6 m in digital CMOS process simulation and analysis of the circuit. In the overall simulation of the circuit, the main observation is that the protection module on the battery charge and dischar

32、ge process by monitoring Vdd potential and Vm potential leaving chip CO side and DO-side changes accordingly. The simulation waveform diagram shown in Figure 7, the overall protection module with the battery voltage changes from the usual mode conversion into overcharge mode, and then return to norm

33、al working mode, and then into the discharge mode, and finally back to normal working mode. As the design in the early stages of the various parameters to be optimized, but to provide a preliminary simulation results.Figure7 Overvoltage and under-voltage protection circuit simulation waveform6.Concl

34、usion Designed a set of battery charging and protection functions in one IC. This design not only can reduce the product, they can reduce the peripheral circuit components. The circuit uses the low-power design. This project is underway to design optimization stage, a complete simulation can not mee

35、t the requirements, but also need to optimize the design of each module circuit.光伏系统中蓄电池的充电保护IC电路设计曾德友，凌朝东，李国刚（华侨大学 元顺集成电路研发中心，福建 泉州 362021）来源：微电子器件与技术 2007年第6期1.引言 太阳能作为一种取之不尽、用之不竭的能源越来越受到重视。太阳能发电已经在很多国家和地区开始普及，太阳能照明也已经在我国很多城市开始投入使用。作为太阳能照明的一个关键部分，蓄电池的充电以及保护显得尤为重要。由于密封免维护铅酸蓄电池具有密封好、无泄漏、无污染、免维护、价格低廉

36、、供电可靠，在电池的整个寿命期间电压稳定且不需要维护等优点，所以在各类需要不间断供电的电子设备和便携式仪器仪表中有着广泛的应用。采用适当的浮充电压，在正常使用(防止过放、过充、过流)时，免维护铅酸蓄电池的浮充寿命可达1216年，如果浮充电压偏差5%则使用寿命缩短1/2。由此可见，充电方式对这类电池的使用寿命有着重大的影响。由于在光伏发电中，蓄电池无需经常维护，因此采用正确的充电方式并采用合理的保护方式，能有效延长蓄电池的使用寿命。传统的充电和保护IC是分立的，占用而积大并且外围电路复杂。目前，市场上还没有真正的将充电与保护功能集成于单一芯片。针对这个问题，设计一种集蓄电池充电和保护功能于一身的

37、IC是十分必要的。2.系统设计与考虑系统主要包括两大部分:蓄电池充电模块和保护模块。这对于将蓄电池作为备用电源使用的场合具有重要意义，它既可以保证外部电源给蓄电池供电，又可以在蓄电池过充、过流以及外部电源断开蓄电池处于过放状态时提供保护，将充电和保护功能集于一身使得电路简化，并且减少宝贵的而积资源浪费。图1是此Ic在光伏发电系统中的具体应用，也是此设计的来源。图1 光伏电路系统框图 免维护铅酸蓄电池的寿命通常为循环寿命和浮充寿命，影响蓄电池寿命的因素有充电速率、放电速率和浮充电压。某些厂家称如果有过充保护电路，充电率可以达到甚至超过2C(C为蓄电池的额定容量)，但是电池厂商推荐的充电率是C/2

38、0C/3。电池的电压与温度有关，温度每升高1，单格电池电压下降4 mV，也就是说电池的浮充电压有负的温度系数-4 mV/。普通充电器在25处为最佳工作状态；在环境温度为0时充电不足；在45时可能因严重过充电缩短电池的使用寿命。要使得蓄电池延长工作寿命，对蓄电池的工作状态要有一定的了解和分析，从而实现对蓄电池进行保护的目的。蓄电池有四种工作状态:通常状态、过电流状态、过充电状态、过放电状态。但是由于不同的过放电电流对蓄电池的容量和寿命所产生的影响不尽相同，所以对蓄电池的过放电电流检测也要分别对待。当电池处于过充电状态的时间较长，则会严重降低电池的容量，缩短电池的寿命。当电池处于过放电状态的时间超过规定时间，则电池由于电池电压过低可能无法再充电使用，从而使得电池寿命降低。 根据以上所述，充电方式对免维护铅酸蓄电池的寿命有很大影响，同时为了使电池始终处于良好的工作状态，蓄电池保护电路必须能够对电池的非正常工作状态进行检测，并作出动作以使电池能够从不正常的工作状态回到通常工作状态，从而实现对电