yelstor
Junior Member level 1
Hi
I am designed a DC/AC inverter. I already made a prototype
![IMAG1000.jpg IMAG1000.jpg](https://www.edaboard.com/data/attachments/69/69426-9418bef0fa9fd23fb8a9a535bc7f456a.jpg)
The output voltage is 120Vrms and current of 8 Arms. DC link is 250vdc, Fsw = 25khz.
Now I'm designing a new version that is coupled to the electrical network, and with corrections of the first version .
The filter is an LC filter with an inductance value of 2mH, and I plan to change the value of the capacitor, by one of greater value (6uF or more).
I had used a capacitor PHE426JF7220JR06L2. The capacitor is film capacitor, and some of its specifications are:
Tolerace: 5%
Capacitance: 2.2uF
Voltage AC: 160Vac
Volatage DC: 300Vdc
When looking for another capacitor of the same series, I see a graphic that I had not seen before
![graphic.PNG graphic.PNG](https://www.edaboard.com/data/attachments/69/69427-a1f7a6d88b075147df0e06077f84bdfa.jpg)
1. What does the previous graphic mean? Before the filter there is a square signal that switches between 250V and -250V@ 25Khz. so what the capacitor derating to 30Vrms for 25Khz ?.
2. is film capacitor the best type for this aplication?. What about ceramic capacitors or other material?
I am designed a DC/AC inverter. I already made a prototype
![IMAG1000.jpg IMAG1000.jpg](https://www.edaboard.com/data/attachments/69/69426-9418bef0fa9fd23fb8a9a535bc7f456a.jpg)
The output voltage is 120Vrms and current of 8 Arms. DC link is 250vdc, Fsw = 25khz.
Now I'm designing a new version that is coupled to the electrical network, and with corrections of the first version .
The filter is an LC filter with an inductance value of 2mH, and I plan to change the value of the capacitor, by one of greater value (6uF or more).
I had used a capacitor PHE426JF7220JR06L2. The capacitor is film capacitor, and some of its specifications are:
Tolerace: 5%
Capacitance: 2.2uF
Voltage AC: 160Vac
Volatage DC: 300Vdc
When looking for another capacitor of the same series, I see a graphic that I had not seen before
![graphic.PNG graphic.PNG](https://www.edaboard.com/data/attachments/69/69427-a1f7a6d88b075147df0e06077f84bdfa.jpg)
1. What does the previous graphic mean? Before the filter there is a square signal that switches between 250V and -250V@ 25Khz. so what the capacitor derating to 30Vrms for 25Khz ?.
2. is film capacitor the best type for this aplication?. What about ceramic capacitors or other material?