汽车HID电子镇流器高压启动电路及控制策略

汽车HID前照灯因瞬间快速启动的要求需要13~25 kV的高压,为了减小电路体积,基于对国内外现有方案的分析,提出了三倍压整流电路和能量压缩的高压启动电路。采用恒电压闭环控制和电流接管电路并在启动后引入低频电流积分控制方法保证了可靠的辉弧过渡,自动适应不同的启动条件和老化程度。在启动阶段加入启动方向随机选择程序,缓解了电极过快烧损且保证了电极烧损的对称性,延长HID前照灯的使用寿命。采用PLC编程进行4万次开关试验的结果表明,该启动电路能可靠完成HID前照灯的启动要求,可靠点灯且灯泡电极无明显的烧损,延长前照灯的使用寿命。

Igniter Circuit and Control Strategy for Automotive HID Headlamp Ballast

In this paper,some related literatures about high voltage ignite circuits used in ballasts are summarized and analyzed a high voltage igniter for achieving high ignite voltage ranged from 13kV to 25kV is designed. Based on energy compression technique,a igniter circuit with voltage-multiplying rectifier and a single transformer that can output enough high voltage pulse for starting and restarting HID headlamp is proposed for reducing the circuit volume.For starting and restarting HID headlamp reliably,voltage close-loop control and a take-over circuit is adapted,and low-frequency current-integration method is presented to ensure glow-to-arc transient and to maintain the arc.A self-adaptive control method for power close loop used for self-match different restart condition and different lamp's age is presented and analyzed,the initial values of transient stage can be obtained during warm-up stage automatically for smoothly transient to steady state.Trough this strategy,the output power,voltage and current can be controlled to suite the actual parameters instead of flicker during whole transient stage.To lighten electrodes' burning and ensure burning symmetrically,and thus lengthen the lamp's life,besides of using the current integer algorithm,selecting restarting direction with a random program is proposed to equate the igniting chance between two electrodes.Controlled with PLC,a switch experiment last 40000 times is performed in different restart condition and reliability is verified.Burning of electrodes is not obvious and is symmetrical.It is shown from the given waveforms that a high ignite voltage ranged form 11kV to 25kV can be obtain and the practical value is dependent on the currently restart condition and lamp's age,the lower restart temperature is,the longer the length of the warm-up stage and the higher the initial power value is,and it is important that the transient stage would be shorter to suit for the lamp's restart temperature.