How realistic is this model for an inductive spike?

I want to model a real-life scenario when a mechanical switch is rapidly opened when passing current through an inductive load. Below is a model and corresponding plots for the switch control (Vn001), switch current I(S1) and a plot to observe the voltage spike occurring at the inductor terminal V(vspike). Initially the switch is ON and after 0.2 seconds the switch is turned OFF.

I set the switch on resistance to 1 Ohm and the off resistance to 10Meg. According to the theory I can understand why the inductor current causes such huge voltage spike when the switch is opened.

But in real life I don't think this crazy voltage makes sense and goes that high.

What happens in reality that we never see like 10 MegaVolts? Or how can we model this to make it more realistic?

edit:

Adding some capacitance for the switch resulted more realistic results:

The moment the switch opens its contact, an arc is immediately forming and dissipating the energy formerly stored in the inductor. You won't get this in a sim. You also have contact capacitance that lowers as the contacts move further apart.

So that's roughly what happens and I'll leave it to you to figure out how to model it.

• I added parallel 10uF cap(just a guess) to the switch, now results are more realistic. I guess in real that capacitance is time dependent and maybe in series I dont know. I added the plots to my edit. Jun 25, 2017 at 17:59
• What is capacitance across that light switch on your wall, when the contacts have separated only 1micron? with 4mm by 4mm contact sizes? C = E0*Er*area/distance = 9e-12Farad/meter * 4mm * 4mm / 0.001mm = 9e-12 * 16 = 150 picroFarad. Jun 25, 2017 at 20:56
• @analogsystemsrf I guess you estimated C1 as 150pF. Should that be in series or in parallel to the switch for the switching action? I added as parallel but have no idea of whether it is correct. Jun 25, 2017 at 22:25
• @user134429 -- in parallel (in series won't work) Jun 25, 2017 at 23:53
• @ThreePhaseEel I see but 150pF parallel cap as C1 in my second model produces again unrealistically huge voltages like a ringing voltage from -10KV to +10KV. In real I would expect max a few hundred volts. What do you think? Am I wasting my time? Is it more complicated than what Im trying to do? Jun 26, 2017 at 0:12

There are standards that recommend peak voltage, rise-time, fall-time and ringing characteristics for representative transients that equipment should withstand in various locations and situations. ANSI / IEEE C62.41 and C62.45 are the ones that I think may be applicable. C62.41 describes a 6 kV ringing impulse with a 0.5 microsecond rise time with the second ringing peak at 60% voltage and 100 kHz ringing for the first cycle after the initial impulse. There also unidirectional impulses with 1.2 and 8 microsecond rise times with the voltages falling to 50% voltage after 50 and 20 microseconds respectively. I have not seen a recent version of that standard, but I don't think it will have changed drastically.

Here is a link that might be helpful. It is out of date, but it should give you an idea of what is involved. If you search you should be able to find something similar that is more recent. If you have the necessary resources, you should read the referenced standards.

Here is a link to some more recent information: