Hello everyone,
I want to know the current factor affecting the RMS value of electrical loading of electrical machine. In most of the applications, sinusoidal current is applied to the machine. Therefore, RMS value is calculated as Arms=A(max)/sqrt(2). Does RMS value of electrical loading of electrical machine depends upon waveform of input current e.g. sqrt(2) is not used for square wave current.?
The effective part of the waveform is the RMS value.Thus, the RMS value depends on the waveform of the input current
Hello, Tanveer! The RMS value is the square root of the mean value of the squared values taken over an interval, i.e. original formula for RMS of any analog signal, including AC current, has procedure of integration. The equation you asked for (Arms=A(max)/sqrt(2)) is a result of integration for the sinusoidal signal. Thus, the RMS value does depend on the shape of the signal. The general expression for RMS and some examples of its application are given in the link. Best wishes!
http://www.raeng.org.uk/publications/other/8-rms
Yes, Total electric loading=Z*I,
Specific electric loading=Z*I/(pi*D)
where, "I" is the RMS value of armature current, "Z" is the total number of armature conductor, "D" is inner diameter of armature.
Hello Tanveer,
Certainly RMS value depends upon the wave shape of the input.
Cosine and sine have the same RMS value, but RMS value of triangular and square wave input will be differet.
Yes the input current's wave shape certainly affects the RMS value of the current through load. If the input current wave shape is non-sinusoidal then it will inherently have higher order harmonic components which will affect the developed torque by inducing ripples in it.
- SH Thilagar
Yes, the RMS value depend on wave form.
In this case, you can no longer use the formula RMS = Amax/sqrt (2). This one is only valid for sinus wave form.
To calculate RMS in this case, use the standard formular
Xrms = sqrt [(x1^2 + x2^2 +... + xn^2)/n]
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