电流型电火花加工电源工作频率和滤波电感确定方法
电流型电加工电源后级为一电子负载,它在工作时对前级变换器的输出电流进行连续不断的斩波,在整个负载范围内(即对应不同的消电离时间和脉冲宽度组合),可以看作是频率可以调节的电子负载,后级的斩波频率为250K(对应消电离时间和脉冲宽度均2
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_0.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_1.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_2.jpg)
2 工作分析
下图为前、后级变换器的主要电路图。其中电容C的容值很小,它的作用是高压引弧放电。具体过程是这样的:当开关M关断时,由于工件还处于开路状态,所以电感中的大电流给C充电,致使工件两端电压线性急剧上升,直至高压击穿正常放电,此后,电流流经工件进行加工,一直延续到M开通时结束。在此,我们假设前级变换器的开关频率为
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_3.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_4.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_3.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_4.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_7.jpg)
1)、
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_8.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_9.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_8.jpg)
在
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_11.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_11.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_13.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_11.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_13.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_13.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_13.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_7.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_13.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_13.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_13.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_22.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_3.jpg)
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_24.jpg)
则上式可以简化为
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_25.jpg)
从上式中可以看出,要满足稳定加工,
![](http://m.amcfsurvey.com/editerupload/fetch/20140213/231249_1_26.jpg)
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