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Diffstat (limited to '1445/CH7/EX7.27/ch7_ex_27.sce')
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1 files changed, 69 insertions, 0 deletions
diff --git a/1445/CH7/EX7.27/ch7_ex_27.sce b/1445/CH7/EX7.27/ch7_ex_27.sce new file mode 100644 index 000000000..ed201edae --- /dev/null +++ b/1445/CH7/EX7.27/ch7_ex_27.sce @@ -0,0 +1,69 @@ +//CHAPTER 7- SINGLE PHASE TRANSFORMER +//Example 27 + +disp("CHAPTER 7"); +disp("EXAMPLE 27"); + +//VARIABLE INITIALIZATION +va=200000; //apparent power +v1=11000; //primary voltage in Volts +v2=400; //secondary voltage in Volts +f=50; +//open circuit parameters +V3=400; +I3=9; +W3=1500; // watts HT side +//short circuit test +Vsc=350; +Isc=20; +Wc=2100; // watts HT side +// +pf=0.8; +//SOLUTION +Voc=V3/sqrt(3); +Io=9; +Wi=W3/3; // watts HT side +Pc=Wi; //core losses +//open circuit +phi0=acos(Wi/(Voc*Io)); +Ic=Io*cos(phi0); +Iphi=Io*sin(phi0); +Rc=Voc/Ic; +X=Voc/Iphi; +disp("SOLUTION (a)"); +disp(sprintf("The value of Ic is %f Amp",Ic)); +disp(sprintf("The value of IΦ is %f Amp",Iphi)); +disp(sprintf("The value of Rc is %f Ohm",Rc)); +disp(sprintf("The value of X is %fΩ",X)); +// +//core loss resistance referred to hv side +Rch=Rc*(v1/Voc)^2; +XphiH=X*(v1/Voc)^2; +disp(sprintf("The value of Rch is %f kΩ",Rch/1000)); +disp(sprintf("The value of XΦh is %f KΩ",XphiH/1000)); +//short circuit +//first find rated current +Isc=va/(3*v1); +Psc=Wc/3; //ohmic loss per phase +phisc=acos(Wc/(Vsc*Isc)); +pf1=cos(phisc); +R_e1=Psc/Isc^2; +Z_e1=Vsc/Isc; +X_e1=sqrt(Z_e1^2-R_e1^2); +disp(sprintf("The value of Power factor is %f",pf1)); +disp(sprintf("The value of Re1 is %f Ohm",R_e1)); +disp(sprintf("The value of Ze1 is %f Ohm",Z_e1)); +disp(sprintf("The value of Xe1 is %fΩ",X_e1)); +// +//efficiency at half load +pf=1; //unity power factor +Pout=(va/3)*(1/2)*pf; +//core losses=Pc +//cuLosses ohmic loss =Psc +Pin=Pout+Pc+(1/2)^2*Psc; +eff=Pout*100/Pin; +disp(sprintf("The efficiency at half load is %f",eff)); + +disp(" "); +// +//END |