摘要
燃油汽车必将随着石油的减少而渐渐从市场上淡去，新的交通工具必将重新占领市场。从能源上说，电能的来源广，尤其是利用太阳能发电和风能发电，让电能变的可再生。近几年，电动车的迅猛发展已经说明电动汽车将是以后的主要交通工具。从环保上说电动车的无污染，也是燃油的高污染所不能比的。
在电动车的使用中，主要的问题就是电池的使用寿命问题，一般铅酸蓄电池就使用三两年。影响蓄电池寿命主要有两个原因：蓄电池质量和充电控制。而且大部分蓄电池又是被充坏的，因此电动车必须要有一个合适的车载无线充电器。根据铅酸蓄电池的指数充电规律，本次设计采用了前期恒流充电，后期恒压充电，最后涓充的三段式充电方法。在充电过程中，为方便用户的使用，LED灯直观的表示了充电的进度，电压电流和容量的液晶显示告诉用户现在电池的详细情况。通过数据的串行通讯，可以让用户在驾驶室就知道电池的情况。本次设计的车载无线充电器用户还可以选择充电方法自动调节充电，改善电池的硫化问题，延长电池的使用寿命。
本次设计的车载无线充电器的关键是开关电源部分。用体积小、重量轻的高频变压器取代体积大的工频变压器，开关电路的拓扑结构的选择，开关器件的选择，输入输出滤波电容的选择，输出电感的选择，在本次设计中都有详细的说明。
本次车载无线充电器的另一设计的关键是软件控制算法的编写。本次设计选用的是AVR单片机ATmega16，通过编程可以实现电压电流的A/D转换，电压电流和容量的显示和传输，利用PWM对恒流恒压和涓流的控制。
关键词：电动车 车载无线充电器 铅酸蓄电池 充电方法
ABSTRACT
The fuel-engine vehicle will be out of the market while the oil is decreasing, then some new vehicle will occupy the market. Speaking of energy, the electricity is a sort of Secondary energy and it can be produced by many kinds of material especially can be produced by the sunshine and the wind which is reproducible. In recent years, the rapid development of the electro-mobile indicates the electro-mobile will become the important electro-mobile. Saying from environmental protection, the electro-mobile is free of contamination, with which the fuel-engine vehicle can not compare.
While using the electro-mobile, the most important problem we meet is the useful life of the battery, usually the lead-acid cell can be used for two or three years. There are two reasons affecting the useful life of the lead-acid cell: the quality of the lead-acid cell and the charging control. Further more the most storage battery is damaged while charging, so there must be a suitable charger for the electro-mobile. In this design of the charger, I adopt the way of the three segments to charge, namely in the prophase charging by the invariable current, in the anaphase, charging by the invariable voltage, finally trickle charging. While charging, in order to use the electro-mobile handily, the LED lights intuitively indicate the charging progress, the voltage, the current and the capacity will be showed on the LCD. By the data serial communication, the user can know the condition of the cell in the driver’s seat. By this vehicle-mounted charger designed the user can also change the charging way to adjust charging automatically, to ameliorate the vulcanization of the cell, to prolong the life of the cell.
When designing this vehicle-mounted charger, the design of the switch power supply is pivotal, the industrial frequency transformer is replaced by the high frequency transformer of which the cubage is small and the weight is light. The choice of the topology structure of the switched circuit, the device of the switches, the in-out filtering capacitance, the out inductance is amply explained in the appendix.
In the design, authoring the controlling software is pivotal too. In this design, I choose the single chip Atmega16,through programming the signal of the voltage and current can be changed from analog to digital, the voltage ,the current and the capacity can be showed and transmitted, the invariable current, the invariable current and trickle charging can be controlled by the way of PWM.
Key words: electro-mobile, vehicle-mounted charger, lead-acid cell, charging way
