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

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

[Torsten]

The right-hand side does not depend on t. Thus V3rms(t) cannot be correct.

Further: How is Y(t) given ? As a list of pairs (t_i,Y(t_i)) ?

[kcl128]

Thank you Torsten. The formula is a standard one used to calculate the root mean square value of a varying voltage (Y) as a function of t. The root part is given by the sqrt, the mean is given by the period t2 - t1. I have used this formula many times in Mathcad but I am missing something in the Matlab code protocols.

Kind Regards

[kcl128]

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]

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

Answer 1

[Torsten]

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.

Answer 2

[kcl128]

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

Answer 3

[kcl128]

Dear Torsten,

Thank you. I now understand the problem.

Kind Regards