figure
plot(t,UUC,'b') title('??2¨oó:UUC') USA=zeros(1,m(2)); USB=zeros(1,m(2)); USC=zeros(1,m(2)); for jj=N/4+1:m(2)
USA(jj)=sqrt((UUA(jj)*UUA(jj)+UUA(jj-N/4)*UUA(jj-N/4))/2); USB(jj)=sqrt((UUB(jj)*UUB(jj)+UUB(jj-N/4)*UUB(jj-N/4))/2); USC(jj)=sqrt((UUC(jj)*UUC(jj)+UUC(jj-N/4)*UUC(jj-N/4))/2); end
for jj=N/4+1:m(2)
ISA(jj)=sqrt((IIA(jj)*IIA(jj)+IIA(jj-N/4)*IIA(jj-N/4))/2); ISB(jj)=sqrt((IIB(jj)*IIB(jj)+IIB(jj-N/4)*IIB(jj-N/4))/2); ISC(jj)=sqrt((IIC(jj)*IIC(jj)+IIC(jj-N/4)*IIC(jj-N/4))/2); end
Um=UUA-UUB; Im=IIA-IIB;
Um1=UUB-UUC; Im1=IIB-IIC; Um2=UUC-UUA; Im2=IIC-IIA; for jj=N/4+1:m(2)
R(jj)=(Um(jj)*Im(jj)+Um(jj-N/4)*Im(jj-N/4))/(Im(jj)*Im(jj)+Im(jj-N/4)*Im(jj-N/4)); X(jj)=(Um(jj-N/4)*Im(jj)-Um(jj)*Im(jj-N/4))/(Im(jj)*Im(jj)+Im(jj-N/4)*Im(jj-N/4));
O(jj)=180/pi*atan((Um(jj-N/4)*Im(jj)-Um(jj)*Im(jj-N/4))/(Um(jj)*Im(jj)+Um(jj-N/4)*Im(jj-N/4)));
R1(jj)=(Um1(jj)*Im1(jj)+Um1(jj-N/4)*Im1(jj-N/4))/(Im1(jj)*Im1(jj)+Im1(jj-N/4)*Im1(jj-N/4));
X1(jj)=(Um1(jj-N/4)*Im1(jj)-Um1(jj)*Im1(jj-N/4))/(Im1(jj)*Im1(jj)+Im1(jj-N/4)*Im1(jj-N/4)); O1(jj)=180/pi*atan((Um1(jj-N/4)*Im1(jj)-Um1(jj)*Im1(jj-N/4))/(Um1(jj)*Im1(jj)+Um1(jj-N/4)*Im1(jj-N/4)));
R2(jj)=(Um2(jj)*Im2(jj)+Um2(jj-N/4)*Im2(jj-N/4))/(Im2(jj)*Im2(jj)+Im2(jj-N/4)*Im2(jj-N/4));
X2(jj)=(Um2(jj-N/4)*Im2(jj)-Um2(jj)*Im2(jj-N/4))/(Im2(jj)*Im2(jj)+Im2(jj-N/4)*Im2(jj-N/4)); O2(jj)=180/pi*atan((Um2(jj-N/4)*Im2(jj)-Um2(jj)*Im2(jj-N/4))/(Um2(jj)*Im2(jj)+Um2(jj-N/4)*Im2(jj-N/4))); end
subplot(231)
plot(t,ISA,t,ISB,t,ISC); title('2aá?μ?μ?μ?á÷á?')
subplot(232)
plot(t,USA,t,USB,t,USC); title('????μ?μ?μ??1óDD§?μ') ylabel('V') subplot(233) plot(t,R); title('????μ?μ?μ?×èóDD§?μ') ylabel('R') subplot(234) plot(t,X); title('????μ?μ?μ??1óDD§?μ') ylabel('X') subplot(235) plot(t,O); title('????μ?μ?×è?1??') ylabel('angle')
Zset=1.0821+i*24.9205; Zm=R+i.*X; Zm1=R1+i.*X1; Zm2=R2+i.*X2; flag=zeros(1,m(2)); for jj=1:m(2)
if abs(Zm(jj)-0.5*Zset)<=0.5*abs(Zset) flag(jj)=1; end
if abs(Zm1(jj)-0.5*Zset)<=0.5*abs(Zset) flag1(jj)=1; end
if abs(Zm2(jj)-0.5*Zset)<=0.5*abs(Zset) flag2(jj)=1; end end figure
subplot(221) plot(t,flag) subplot(222) plot(t,flag1) subplot(223) plot(t,flag2)
clc; clear;
a=load('E:\\U_DATA_3.txt'); b=load('E:\\I_DATA_3.txt'); t=a(:,1)';
UA=a(:,2)'; UB=a(:,3)'; UC=a(:,4)'; IA=b(:,2)'; IB=b(:,3)'; IC=b(:,4)';
Ts=t(1,2)-t(1,1); N=0.02/Ts; m=size(t);
IIA=zeros(1,m(2)); IIB=zeros(1,m(2)); IIC=zeros(1,m(2)); for j=N/5+1:m(2)
IIA(j)=(IA(j)-IA(j-N/5))/2; IIB(j)=(IB(j)-IB(j-N/5))/2; IIC(j)=(IC(j)-IC(j-N/5))/2; end figure plot(t,IA)
title('??2¨?°:IA') figure
plot(t,IIA,'r') title('??2¨oó:IIA') figure
plot(t,IIB,'g') title('??2¨oó:IIB') figure
plot(t,IIC,'b') title('??2¨oó:IIC')
四、实验结果分析
滤波前:IA1000080006000400020000-2000-4000-600000.10.20.30.40.50.60.70.80.91滤波后:IIA3000200010000-1000-2000-300000.10.20.30.40.50.60.70.80.91
滤波后:IIB3000200010000-1000-2000-300000.10.20.30.40.50.60.70.80.911x 105滤波前:UA0.80.60.40.20-0.2-0.4-0.6-0.8-100.10.20.30.40.50.60.70.80.916x 104滤波后:UUB543210-1-2-3-400.10.20.30.40.50.60.70.80.91110.80.80.60.60.40.40.20.2000.51000.5110.80.60.40.2000.51滤波后:IIC25002000150010005000-500-1000-1500-2000-250000.10.20.30.40.50.60.70.80.91波后:UUA4x 104滤3210-1-2-3-4-500.10.20.30.40.50.60.70.80.91测量到的电流量计算到的4电压有效值计算到的电阻有效值20006x 10150150041001000VR5050020000.51000.51-5000.51计算到的电抗有效值计算到的阻抗角201001050e0lXgn0a-10-50-2000.51-10000.51
滤波后:IIA滤波前:IA10000400030008000200060001000400020000-2000-4000-60000-1000-2000-3000-400000.10.20.30.40.50.60.70.80.9100.10.20.30.40.50.60.70.80.91滤波后:IIB40003000200010000-1000-2000-3000-400040003000200010000-1000-2000-3000-4000滤波后:IIC00.10.20.30.40.50.60.70.80.9100.10.20.30.40.50.60.70.80.91
微机距离保护与线路参数和线路短路长度密切相关，微机距离保护算法中，给出线路参数及短路线路长度后，计算其短路阻抗根据整定原则确定其整定值。实验中0.5秒时发生短路，得到的短路阻抗如图所示，修改整定值后，断路器均收到跳闸信号
五、心得体会
了解了微型机保护系统的硬件的组成部分。以及组成原理图。微机保护软件的逻辑功能在电力系统中的实际应用。学习了电力系统中微机型电流、电压保护时间、电流、电压整定值的调整方法。