8 11-1 Mutual inductance i() U=r ah () 91 p21s911 12 22 q12q22
dt di = L §11-1 Mutual inductance 1 i 11 21 2 i 12 22 12 22 + (t) − i(t) L 21 11 L1 L2 L1 L2
M A current i, at Li produces an open circuit voltage u,at L ○L32U y21=M21U2= dv21=M21 t M A current i, at L2 produces an 十 open circuit voltage U,atLIs L Y12=M12L2 0,dv12 M d t 12 dt The mutual inductance: M12-M2IM(H) The coefficient of coupling: k=M ≤1 (i2→DC.U,U2=0) 1三
A current i1 at L1 produces an open circuit voltage at L2 . 2 21 21 1 = M i A current i2 at L2 produces an open circuit voltage at L1 . 1 12 12 2 = M i The mutual inductance: M12=M21=M(H) The coefficient of coupling: 1 1 2 = L L M k ( . , 0) If i 1, i 2 DC 1 2 = − + 2 1 i 2 i − + 1 L1 L2 M L1 L2 M dt di M dt d 1 21 21 2 = = dt di M dt d 2 12 12 1 = =
TX1 V1 311Vag HVdc 100 PARAMETERS: PARAMETERS coupling =1 150mV 100mV 50mV 0.4 0.6 1.0 口V(R1:2,R1:1)
coupling 0 0.2 0.4 0.6 0.8 1.0 V(R1:2,R1:1) 0V 50mV 100mV 150mV V+ PARAMETERS: L2 = 1m V- TX1 {L2} R1 100 V1 311Vac 0Vdc PARAMETERS: coupling = 1 R2 1k
“ dot convention” If,i,(entering two coils) produce flux linkages which are increase each other, then the two terminals(l, 2 or 1 2) are defined as“ dot terminals”(“ same name terminals”) i↑ p, 12 2 2
“dot convention” L2 2 i 1 i L1 If i1 ,i2 (entering two coils) produce flux linkages which are increase each other, then the two terminals(1, 2 or 1’ , 2 ’ ) are defined as “dot terminals”(“same name terminals”) . 1 i 11 21 L1 L2 2 i 12 22 1 1' 2 2
Determine“ dot terminals” Li-source L2--voltage-meter K--close, --upscale. The terminal connected (+ polarity of the source and the terminal connected (+ polarity fv are defined as“ dot terminals
V + − 1 i L1 L2 L1 --source L2 --voltage-meter K--close, V --upscale. The terminal connected (+) polarity of the source and the terminal connected (+) polarity of are defined as “ dot terminals” V Determine “dot terminals”