单相变压器实验

1.空载试验

n=10;

U0=[65.7 60.5 58.5 56.1 54.5 49.3 40.8 30.7 20.2 11.3];

I0=[0.103 0.075 0.066 0.057 0.052 0.040 0.029 0.020 0.014 0.009];

P0=[1.7 1.5 1.5 1.3 1.3 1.1 0.7 0.5 0.3 0];

UAX=[256 235.5 227.5 217.5 210.5 190.0 155.0 115.0 72.5 40.0];

%COSfy0=P0./(U0.*I0)

COSfy0=[0.253 0.331 0.389 0.407 0.459 0.558 0.592 0.814 1.0 1];

K=sum(UAX./U0)/n;

 

Uy=polyfit(I0,U0,3)

Ix=0:0.0001:0.1;

U=polyval(Uy,Ix);

plot(I0,U0,'*',Ix,U)

grid

axis([0 0.1 0 65])

 

figure

Py=polyfit(U0,P0,3)

Ux=0:0.01:60;

P=polyval(Py,Ux);

plot(U0,P0,'*',Ux,P)

grid

axis([0 60 0 1.6])

 

figure

Cy=polyfit(U0,COSfy0,1)

Ux=0:0.01:60;

C=polyval(Cy,Ux);

plot(U0,COSfy0,'*',Ux,C)

grid

axis([0 60 0 1])

 

%由空载实验得到的数据，计算激磁参数

U0=55;

I0=0.052;

P0=1.2867;

Zm=U0/I0

Rm=P0/I0^2

Xm=sqrt(Zm^2-Rm^2)

 

Zm =1.0577e+003

Rm =475.8506

Xm =944.6053

2.短路实验

n=8;

Uk=[25.6 24.5 22.5 20.9 18.3 11.3 7.1 3.7];

Ik=[0.388 0.371 0.340 0.316 0.276 0.171 0.107 0.057];

Pk=[4.7 4.3 3.5 3.1 2.3 0.8 0.3 0];

%COSfyk=Pk./(Uk.*Ik);

COSfyk=[0.473 0.473 0.458 0.469 0.456 0.414 0.400 0.4];

 

Uy=polyfit(Ik,Uk,3)

Ix=0:0.001:0.4;

U=polyval(Uy,Ix);

plot(Ik,Uk,'*',Ix,U)

grid

axis([0 0.4 0 30])

 

figure

Py=polyfit(Ik,Pk,3)

Ix=0:0.001:0.4;

P=polyval(Py,Ix);

plot(Ik,Pk,'*',Ix,P)

grid

axis([0 0.4 0 5])

 

figure

Cy=polyfit(Ik,COSfyk,1)

Ix=0:0.001:0.4;

C=polyval(Cy,Ix);

plot(Ik,COSfyk,'*',Ix,C)

grid

axis([0 0.4 0 1])

 

%由短路实验得到的数据，计算等效漏阻抗

Uk=23.2;

Ik=0.35;

Pk=3.78;

In=0.35;

Un=55;

k=3.8;

T=21.5;

Zk=Uk/Ik/k^2

Rk=Pk/(Ik^2*k^2)

Xk=sqrt(Zk^2-Rk^2)

Rk75=Rk*(234.5+75)/(234.5+T)

Zk75=sqrt(Xk^2+Rk75^2)

uk=In*Zk75/Un

ukr=In*Rk75/Un

ukx=In*Xk/Un

 

Zk = 4.5904

Rk = 2.1369

Xk =4.0627

Rk75 =2.5835

Zk75 =4.8146

uk =3.06%

ukr =1.64%

ukx =2.59%

3.负载实验

U2=[230 225 223 222 218 217];

I2=[0 0.15 0.2 0.25 0.3 0.315];

plot(I2,U2,'*')

grid

axis([0 0.35 0 250])