Hi Steve,
To be perfectly honest, since I have no formal training in electrical engineering, I’m afraid your inquiry is beyond my collective expertise. 🤪 I will say that I’ve heard that the voltage reversal vs shot life issues can be reasonably dealt with by choosing a cap whose maximum voltage rating is a minimum of 3x the peak input AC voltage (rms x 1.41), assuming that it is properly designed with a low loss dielectric system. My transformer can produce up to 16.8 kvAC so 16800 x 1.41=23688, and 23688 x 3 = 71,064. My primary tank capacitor is rated at 75 kV, so I should be ‘good’.
David
Sent from my iPhone
On Sep 13, 2020, at 12:38 PM, Steve White <steve.white1@xxxxxxxxx> wrote:
Hi David,
I've always wondered if a ARSG has some negative effect on capacitor life. With a ARSG essentially firing at slow-rolling random times it seems as if many of those firing events would be during capacitor voltage reversals during the charging process. Of course the frequency of the 60 Hz charging voltage reversals is much lower than the voltage reversals experienced in the primary coil tank circuit. Since percent voltage reversal is a key capacitor lifetime parameter, it seems like something to consider.
That potential problem can't happen with a SRSG because the firing points are nominally at 0 and 180 degrees for a 120 PPS system or at 0, 90, 180, and 225 degrees for a 240 PPS system.
Maybe the effect is negligible.
Thoughts?
Steve White
Cedar Rapids, Iowa
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