pik1432

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MaplePrimes Activity


These are replies submitted by pik1432

@tomleslie : Thank you for your checking and the answer. I tested with the latest Maple (2021.1) and saw the expected results. 

 

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

@dharr: Thank you for the information. It worked!

 

 

@Carl Love : Thank you for your detailed information. 

@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. 

 

@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. 

@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

@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. 

 

@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

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

@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. 

 

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

@Kitonum : Thank you for the additional information. 

@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

@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

 

 

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