Check my reactance calculations

[snoop33]

Head scratching this one. I'm counteracting the reactance of an inductor with capacitors and have computed the ideal capacitance and reactance delta which should lead the phase closest to zero.

For human use, frequency is converted to kph.

From the graph we can see the switch point is around the 17kph mark, that is, both sets of capacitors should perform about the same.

In real-life it's way off, the switch point is 27kph.

Coincidentally if I divide the inductance by half it's almost bang on at 26kph. Urm...

Anything wrong with the calcs?

[ahbushnell]

For human use, frequency is converted to kph.

Excuse my ignorance.  What is kph and which humans use that for frequency? 

Thanks for spinning me up. 
Andy

[snoop33]

Just ignore it.

[Faringdon]

its just complex numbers.....if they are in series, then Z = jwL + 1/jwC = jwL - J/Wc

So to get in phase you make the imag part  zero.....so wL - 1/wC = 0

[snoop33]

Sure, but that's not answering the question.

[pardo-bsso]

Dumb question because I'm not completely familiar with your application.

What's the real device and how did you measure the reactance at different speeds/frequencies?
(about your factor of 2, w = pi*f, perhaps you missed one?)

[snoop33]

The real device is a generator.

I think you're asking how I know the calculated figures are wrong. Inductance is provided by the manufacturer. When the phase angle is closest to zero then LCR becomes R (ignoring some series resistance in the capacitors and inductor). By reducing R till MPPT is reached, when the two capacitance values give the same reading then that is the ideal frequency switch point (both phase angles are the same).

The spreadsheet is attached, I can't see anything wrong with the calculations, so it remains a bewilderment.

[snoop33]

It's looking like they are correct, the issue is the inductance value supplied is incorrect.