在what is the difference between ordinary high-voltage ceramic capacitors and gac high-voltage ceramic capacitors in ac applications? why is it better to use gac high-voltage capacitors on power equipment? this article will answer this question for you.
ordinary high-voltage ceramic capacitors, in the application of ac equipment, mostly refer to ceramic capacitors of n4700 medium. gac high-voltage capacitors are also attributed to ceramic capacitors, but the media and process are very different. the following table is listed, it can be seen that the pros and cons are fundamental.
比较项目 | n4700高压陶瓷电容器 | gac高压陶瓷电容器 |
同一规格型号 | 40kv 1000pf | 40kv 1000pf |
工艺 | 粉料-压制-烧结-磨片-涂银-环氧灌封 | 粉料-烧制-灌注-磨片-涂银-环氧灌封 |
温度变化率 | 28% at 85c | 0.9% at 85c |
额定直流电压 | 40kvdc | 40kvdc |
额定交流电压 | 10kvac | 10kvac |
测试电压 | 80kvdc or 45kvac测试2分钟 | 80kvdc or 4kvac 测试2分钟 |
局部放电 | 小于20pc | 小于3pc |
尺寸 | 直径45mm,厚度34mm,高度38mm | 直径60mm,厚度18mm,高度22mm |
电压线性度 | 大于5% | 小于0.2% |
高低温特性 | -40c~ 85c | -55c~ 125c |
物料编码 | mzd45dl40kv102j | mzd60gac40kv102j |
价格 | 约200元/只 | 约380元/只 |
as seen from the above table, a bolt-type high-voltage capacitor with the same voltage and capacity is produced by two different processes and different materials. two different high-voltage capacitors are obtained. in terms of product performance, the gap is huge. first, the partial discharge required by the power sector, the gac high-voltage capacitor bureau is much smaller than the n4700 ceramic capacitor. secondly, from the temperature change rate, the gac change is extremely small, and the ordinary n4700 high voltage is completely incomparable. because in china in the summer, the outdoor temperature will reach nearly 40 degrees, and the power equipment will have a temperature of nearly 80 degrees in the sun. at such a high temperature, if ordinary dl (n4700) material is used, the rate of change of the capacitor itself is greatly scary, completely can not use the temperature change rate of about 28%, which is not considered by power technology designers. the gac high voltage capacitor completely solves this problem.
in the above table, the only thing that can be called the disadvantage is that the diameter of the gac is larger. however, the diameter of 60mm is acceptable for most electrical equipment. for the under-designer, the development of new dielectric materials is constantly advancing. , is a job that can never stop.