§76 Phasor relationships for r、 L and c Ra i R R 2 + jfu=√2cos(a+9)i=√2Icos(ar+g) 2V cos(at+9)=Rv2I cos(at +) ∠=RI∠q (9= U,i--in Phase RI
§7-6 Phasor relationships for R、 L and C i + − R • I + − • V R = Ri i f = 2V cos(t +) i = 2I cos(t + ) 2V cos(t +) = R 2I cos(t +) ( ,i i n phase) V RI = − − = • • V = R I R：
VOFF=O VAMPL 311 FREQ 50 2 0 400 ………… 400 10ms 口V(V1:+,0)◇-I(R1) Time
R 1 2 V+ V- V1 FREQ = 50 VAMPL = 311 VOFF = 0 0 I Time 0s 10ms 20ms 30ms 40ms 50ms V(V1:+,0) -I(R1) -400 0 400
L L i(t o(t) U(t)= 山山 e c0s90°+jsin90°=j if u=x2y cos(at+9) y leads I by90° i=√2cos(or+) joL--impedance( 2) 2V cos(at +9) (阻抗) QL√2Isin(or+p) oL--inductor reac tan ce =o√2 I cos(ar+g+90°) (感抗) 1∠9=joLI∠q V=jaL
L ： dt di ( t ) = L V = jLI • • V = j L I e j j j = + = cos90 sin90 90 V leads I by 90 • • jL − −impedance ( ) （阻抗） L − −inductor reac tan ce （感抗） + ( t ) − i ( t ) L •I + − •VL •I •V 2 cos( ) 2 cos( ) = + = + i I t i f V t 2 sin( ) 2 cos( ) = − + + L I t V t = L 2 I cos(t + + 90 )
R2 0.1 √1 VOFF =0 VAMPL =311 0.01H FREQ =50 0 400 …+“64 ……… ……… 400 1.00s 1.01s 1.03s 1.04s 1.058 口I(L1)◇V(L1:1,0) Tim
R 2 0.1 V+ 0 VL1 0.01H 1 2 I V1 FREQ = 50 VAMPL = 311 VOFF = 0 Time 1.00s 1.01s 1.02s 1.03s 1.04s 1.05s I(L1) V(L1:1,0) -400 0 400
i(t)=C I leads v by 90 f 2y cos(at +9) ,(-90 COS (-900)+jsi(-90)= i=√2Icos(or+p) I cos( at leads by-90° -C√2sin(or+9) j一-- impedance(2) oC =C√2cos(at+9+90° I∠q=joCV∠9 capacitor reac tance (容抗) 1=jack Jo
C： C i + − C • I + − • V dt d i t C ( ) = I = jCV • • I = jCV • • • = = − I C I j j C V 1 1 I leadsV by 90 • • ( ) 1 − − −impedance C j • I • V capacitor reac tance C − − − 1 （容抗） 2 cos( ) 2 cos( ) = + = + i I t i f V t e j j j = − + − = − − cos( 90 ) sin( 90 ) ( 90 ) − 90 • • V leads I by 2 sin( ) 2 cos( ) = − + + C V t I t = C 2V cos(t + + 90)
VOFF=0 R2 VAMPL =311 FREQ =50 100 2000u 400 10ms 20ms 30ms 50ms 口-I(C1)◇V(V1:+,0)
V- I C 1 2000u 0 V+ V1 FREQ = 50 VAMPL = 311 VOFF = 0 R 2 100 Time 0s 10ms 20ms 30ms 40ms 50ms -I(C1) V(V1:+,0) -400 0 400