To All; I found a significant error in the LTspice analysis. I was wondering how the current could jump instantaneously at zero when the voltage is applied at the peak. That violates magnetism.
It turns out it doesn't. When LTspice starts an analysis, it first calculates the operating point. For the Sine voltage source at 90 degrees, it applies the full voltage across the load. In this case, it was 169.7V across 1 ohm, resulting in 169.7 Amps. That is what was plotted, and is a significant error. I embarked on a search to find examples where switching at the peak could reduce the inrush current. Out of 13 examples I analyzed, I found only one that involves unloaded transformers. I found many references that discuss transformer inrush current caused by core saturation. This is a serious problem as it puts stress on the components and reduces operating life. I could find no reference that states switching at the peak would reduce or eliminate the inrush current. I also found most major suppliers do not offer SSR's that will switch at the peak. Obviously, switching at the peak would be worse for capacitive loads. This was a major project and turned out to take a lot more time and effort than expected. For those who may be interested, the results are shown at http://www.pst.netii.net/timenuts/zvs.htm MRM _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
