Definit integral within a larger equation for a root mean square calculation

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kcl128 2018-4-4

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回答： kcl128 2018-4-5

I am struggling to apply the correct code to evaluate an equation with an integral included. File attached. Any pointers gratefully received.

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kcl128 2018-4-4

The formula that I pasted in to the question is misleading, for which I apologise. I copied it directly from Mathcad but V3rms is expressed as a function of t (V3rms(t)) only so that I could plot V3rms against time. So the formula is corrct but it should just read (V3rms = etc.

Sorry.

Torsten 2018-4-5

编辑：Torsten 2018-4-5

And how is Y(t) given ? As an explicit function ? As a list of pairs (t_i,Y(t_i)) ?

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Answer 1

Torsten 2018-4-5

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编辑：Torsten 2018-4-5

在 MATLAB Online 中打开

t0 = 0;
t1 = 0.01;
f = 1.0/0.02;
Vrms = sqrt(1/(t1-t0)*integral(@(t)sin(2*pi*t*f).^2,t0,t1))

Best wishes

Torsten.

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Answer 2

kcl128 2018-4-5

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Mathcad extract.pdf

Good morning Torsten, Y is the sum of two sinusoidal voltages sampled over a period of 10 milliseconds (t2 = 10ms and t1 = 0ms). One sinusoidal voltage is at the fundamental frequency of 50 hz and the other at the third harmonic of 150 hz. Attached is an extract from a Mathcad calculation.

Kind Regards