transient process in an induction motor
transient process in an induction motor
(OP)
if anyone can show me how to use the numeric method runge-kutta to calculate the start of an induction motor in the transient period ,if you please with an example using parameters .
with regards
with regards





RE: transient process in an induction motor
dw/dt = (Telec-Tmech)/J
where w = 2*pi*speed
Telec = motor torque as function of speed
Tmech = pump torque as function of speed
J = rotational inertia
Rearrange as dt = Jdw/(Telec-Tmech),
then integrate both sides to give:
t = J*Integral(1/[Telec-Tmech])dw from w=0 to w=2*Pi*F_operating.
If you know Telec and Tmech as a function of speed than the numerical integration is trivial and can be done on an excel spreadsheet.
You may wish to add a refinement which adjusts Telec based on V^2 if power system characteristics are known.
RE: transient process in an induction motor
w=(2/p)x(ws-wr)=±(2/p)ws(1-s)in rad/s
ws=2xpixfs in rad/s
fs=frequency of supply voltage in Hz
s=slip in per unit
wr=2xpixfr in rad/s
fr is rotor current frequency in Hz
p is number of poles of the machine
RE: transient process in an induction motor
If any clarification is needed, it is that F_operating represents operating mechanical speed. (That should be obvious from the context).
RE: transient process in an induction motor
regards
RE: transient process in an induction motor
thank you
RE: transient process in an induction motor
1. Arthur R. Bergen "Power Systems Analysis" Prentice-Hall, Inc., 1986
Page 313 Equation 10.44 Mechanical equation
J(theta)"+D(theta)'+iq(lambdad)-Id(lambdaq)=Tm
in terms of Park Variables. Then, apply the Runge-Kutta Method.
2. Alternately, the engineering standard is over the motor acceleration time calculation, e.g.
Section 9.6.5 The Speed-Torque and Motor Accelerating Time Analysis on page 231 of IEEE Std 399-1990 (or newer issues) IEEE Recommended Practice for Industrial and Commercial Power System Analysis.
RE: transient process in an induction motor
Start with the rotational version of a=F/m
dw/dt = (Telec-Tmech)/J
where w = 2*pi*speed
///the "speed" instead of "frequency" is consider objectionable and confusing in this equation. Check any textbook on this subject. If you do not know which one, let me know, I will post some.\\\