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pik1432

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6 years, 122 days
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pik1432 245
June 18 2021
0 0

@dharr : Thank you for the information. Probably that would make a worksheet look amenable to electrical engineers. 

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pik1432 245
June 17 2021
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@dharr: Thank you for the information. It worked!

 

 

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pik1432 245
June 13 2021
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@Carl Love : Thank you for your detailed information. 

Thank you!...

pik1432 245
June 13 2021
0 0

@acer : Thank you for clarifying the real issue. My shallow knowledge led me to believe that the difference was the reason for seemingly not working operation. 

 

Thank you!...

pik1432 245
June 13 2021
0 0

@nm : Thank you for the answer. It was because of a less mindful copy and paste. The line labeled as '#2' used what you've suggested. 

Thank you!...

pik1432 245
April 17 2021
0 0

@Carl Love Thank you for your insight. I verified it with the worksheet below. However, I did not have the luck in the 'i__fdn, n=2/3/4/5' expression. 


 

> 

restart;
> 

with(LinearAlgebra):
> 

Digits := 6:
> 

j := I:
> 

L__adpu := 1.66;
L__aqpu := 1.61;
L__lpu := 0.15;
R__apu := 0.003;
E__tpu := 1.0;
MVA := 555;

1.66

  

1.61

  

.15

  

0.3e-2

  

1.0

  

555

 (1)
> 

A__sat := 0.0312500:
B__sat := 6.93147:
> 

I__tpu_compare := (P__t - j* Q__t) / E__tpu;

-(1.00000*I)*Q__t+1.00000*P__t

 (2)
> 

I__tpu_a := abs(I__tpu_compare);

abs(-(1.00000*I)*Q__t+1.00000*P__t)

 (3)
> 

Phi := arccos(P__t / (I__tpu_a * E__tpu));

arccos(1.00000*P__t/abs(-(1.00000*I)*Q__t+1.00000*P__t))

 (4)
> 

E__a__tilde := E__tpu + (R__apu + j * L__lpu) * I__tpu_compare;

1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t)

 (5)
> 

psi__at := abs(E__a__tilde);

abs(1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t))

 (6)
> 

psi__I := A__sat * exp(B__sat * (psi__at - 0.8));

0.312500e-1*exp(6.93147*abs(1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t))-5.54518)

 (7)
> 

K__sd := psi__at / (psi__at + psi__I);

abs(1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t))/(abs(1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t))+0.312500e-1*exp(6.93147*abs(1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t))-5.54518))

 (8)
> 

K__sq := K__sd;

abs(1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t))/(abs(1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t))+0.312500e-1*exp(6.93147*abs(1.0+(0.3e-2+.15*I)*(-(1.00000*I)*Q__t+1.00000*P__t))-5.54518))

 (9)
> 

X__ad := K__sd * L__adpu:
> 

X__d := X__ad + L__lpu:
> 

X__aq := K__sq * L__aqpu:
> 

X__q := X__aq + L__lpu:
> 

delta__i := arctan((X__q * I__tpu_a * cos(Phi) - R__apu * I__tpu_a * sin(Phi))/(E__tpu + R__apu * I__tpu_a * cos(Phi) + X__q * I__tpu_a * sin(Phi))):
> 

e__q := E__tpu * cos(delta__i):
> 

i__d := I__tpu_a * sin(delta__i + Phi):
> 

i__q := I__tpu_a * cos(delta__i + Phi):
> 

i__fd := (e__q + R__apu * i__q + X__d * i__d)/(X__ad):
> 

i_armature := sqrt(i__d^2 + i__q^2):
> 

i_armature2 := simplify(subs(P__t = 0, i_armature)); #by Carl Love

1.*abs(Q__t)

 (10)
> 

i_armature3 := simplify(subs(P__t = 0.25, i_armature));

abs(I*Q__t-.250000)

 (11)
> 

i_armature4 := simplify(subs(P__t = 0.5, i_armature));

abs(I*Q__t-.500000)

 (12)
> 

i_armature5 := simplify(subs(P__t = 0.9, i_armature));

abs(I*Q__t-.900000)

 (13)
> 

plotA := plot(i_armature2, Q__t = -0.6..0.6):
> 

plotB := plot(i_armature3, Q__t = -0.6..0.6):
> 

plotC := plot(i_armature4, Q__t = -0.6..0.6):
> 

plotD := plot(i_armature5, Q__t = -0.6..0.6):
> 

plots:-display([plotA, plotB, plotC, plotD]);

 
> 

i__fd2 := simplify(subs(P__t = 0, i__fd)) assuming Q__t::real;

0.238650e-1*(((0.757273e-1*abs(Q__t)*(1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)+0.236648e-2*abs(Q__t)*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518))*cos(arctan(0.3e-2*((1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)+0.312500e-1*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518))*abs(Q__t)/((1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)+0.312500e-1*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518)+1.76000*abs(Q__t)*(1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)+0.468750e-2*abs(Q__t)*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518)))-1.57080)+(-45.6887*abs(Q__t)*(1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)-.118324*abs(Q__t)*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518))*sin(arctan(0.3e-2*((1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)+0.312500e-1*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518))*abs(Q__t)/((1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)+0.312500e-1*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518)+1.76000*abs(Q__t)*(1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)+0.468750e-2*abs(Q__t)*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518)))-1.57080))*((0.625e-1+.119375*abs(Q__t)+0.165006e-1*Q__t^2)*(1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518)+(0.976562e-3+0.292968e-3*abs(Q__t)+0.219815e-4*Q__t^2)*exp(13.8629*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-11.0904)+0.792317e-1*abs(Q__t)^3+(3.52+1.056*Q__t)*abs(Q__t)+1.0000+.3*Q__t+3.12012*Q__t^2+.929283*Q__t^3+0.697241e-1*Q__t^4)^(1/2)+(1.57765+1.50666*abs(Q__t))*(1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518)+(0.246508e-1+0.369761e-2*abs(Q__t))*exp(13.8629*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-11.0904)+(1.00000*Q__t^2+13.3280*Q__t+44.4266)*abs(Q__t)+25.2424+7.57273*Q__t+.568180*Q__t^2)/(((0.625e-1+.119375*abs(Q__t)+0.165006e-1*Q__t^2)*(1.00+.3*Q__t+0.22509e-1*Q__t^2)^(1/2)*exp(6.93147*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-5.54518)+(0.976562e-3+0.292968e-3*abs(Q__t)+0.219815e-4*Q__t^2)*exp(13.8629*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2)-11.0904)+0.792317e-1*abs(Q__t)^3+(3.52+1.056*Q__t)*abs(Q__t)+1.0000+.3*Q__t+3.12012*Q__t^2+.929283*Q__t^3+0.697241e-1*Q__t^4)^(1/2)*(1.00+.300000*Q__t+0.225090e-1*Q__t^2)^(1/2))

 (14)
> 

i__fd3 := simplify(subs(P__t = 0.25, i__fd)):
> 

i__fd4 := simplify(subs(P__t = 0.5, i__fd)):
> 

i__fd5 := simplify(subs(P__t = 0.9, i__fd)):
> 

plotD := plot(i__fd2, Q__t = -0.6..0.6):
> 

plotE := plot(i__fd3, Q__t = -0.6..0.6):
> 

plotF := plot(i__fd4, Q__t = -0.6..0.6):
> 

plotG := plot(i__fd5, Q__t = -0.6..0.6):
> 

plots:-display([plotD, plotE, plotF, plotG]);

 
> 

#plot([i__fd2, i_armature2, Q__t = -0.6..0.6]);
> 

 

> 

plot3d(i_armature, P__t = 0..1.0, Q__t = -0.6..0.6);

 
> 

plot3d(i__fd, P__t = 0..1.0, Q__t = -0.6..0.6);

 
> 

 


 

Download Kundur_Cp3_Ex4_A_m1.mw

Thank you!...

pik1432 245
April 17 2021
0 0

@tomleslie : Thank you for your attention to the question. However, it is obvious that both functions, 'i_armature2', 'i_fd2', became single variable functions, taking Q__t as the only independent variable. The given P__t value pinned the other variable in both functions.  Perhaps my expression was not clear, but what I wanted to was to draw a plot, where those two functions are mapped to the x-axis and y-axis, similar to plot of two parametric functions. 

 

Thank you!...

pik1432 245
April 07 2021
0 0

@Pascal4QM Thank you for pointing to the informative material. Most of the description there was beyond my understanding, but I was able to pick up a couple of clauses there and to complete what I wanted to do. The attached worksheet would show the result. 

Download Kundur_Cp5_Ex1ab.mw

Thank you!...

pik1432 245
March 17 2021
0 0

@acer : Thank you for your solution. It worked!

Thank you!...

pik1432 245
March 16 2021
0 0

@acer : Sorry for coming back with similar issues. I keep the answers from this forum at my personal archive (in Endnote), but this time I was not diligent enough to check it first. 

 

Thank you!...

pik1432 245
March 16 2021
0 0

@Carl Love Thank you for pointing the typo. I assumed 'Re:' stands for 'Regarding'. 

Thank you!...

pik1432 245
March 09 2021
0 0

@Kitonum : Thank you for the additional information. 

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pik1432 245
March 09 2021
0 0

@dharr: Thank you for pointing out the error. After correcting it, I was able to see this:

 
 

> 

restart:
> 

# by dharr
> 

arctan_expression := arctan(omega*L/R);

arctan(omega*L/R)

 (1)
> 

arctan_expression2 := arctan(L*omega, R);

arctan(L*omega, R)

 (2)
> 

evalb(arctan_expression = arctan_expression2) assuming L::positive, omega::positive, R::positive;

true

 (3)
> 

is(arctan_expression = arctan_expression2) assuming L::positive, omega::positive, R::positive;

true

 (4)
> 

 


 

Download Q20210308_answers3.mw

Thank you!...

pik1432 245
February 08 2021
0 0

@Kitonum Thank you for your answers. I saw that all of them worked. The attached worksheet file is there I rewalked your answers. 

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/q20210206_answers.mw .

Download q20210206_answers.mw

 

 

Thank you!...

pik1432 245
February 05 2021
0 0

@Kitonum Thank you for showing the new way.!



Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/q20210204_answers_m1.mw .
 

Download q20210204_answers_m1.mw

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