High voltage capacitor lifetime is generally a very strong function of the operating voltage. In addition, the voltage reversal applied to the capacitor can also influence the lifetime.
For plastic film capacitors, the lifetime of a capacitor in terms of N (number of discharges) is generally as follows:
N = number of discharges to failure
V = application operating voltage
Vb = capacitor breakdown voltage
d = dielectric thickness
b= thickness exponent, typically less than 3
Q = circuit quality factor
The circuit quality factor is generally related to the voltage reversal as follows:
Vr = voltage reversal (0 < Vr < 1 so that a voltage reversal of 50% yields a Vr = 0.5)
For ceramic dielectric capacitors, the lifetime of a capacitor is generally as follows:
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