《GCL并联谐振电路》PPT课件.ppt

13-4 GCL并联谐振电路,Y(j)= = G + j( ) =|Y|() |Y| = () =,.,.,G,jL,Is=Isis固定、可变 GC、L损耗电导,I,.,1.谐振条件 总B=0 0 C = 0 Y(j)=G Is和U同相 0 = 并联谐振频率 2.= 0 时电压、电流、阻抗 Z0= = =R0 谐振阻抗(最大、呈电阻性) U0= = =R0Is (最大、且U0和I0同相),.,.,.,.,.,.,.,.,IL0= U0 = Is = -jQIs IC0= j0C U0 = j0C R0 Is = jQIs IR0= G U0 = Is Q= =0 C R0 = 并谐电路的品质因数 IC0 = IL0= Q Is (电流谐振) IL= Q Is 环流 BW=C2 -C1 = Q BW Q BW,.,.,.,.,.,.,.,.,.,.,.,3.频率特性 H(j)= = = = = = H(j)= = R0 = , Is R0 = U0,.,.,并谐: = = ()= =u-is 串谐: = = ()= =i-us,.,.,.,.,4.有载Q值 QL 并：Q =0 C R0 = 空载Q值(并谐回路Q值) R0q = R0RsRL (有载谐振阻抗) QL= =0CR0q= 有载Q值 (要求Rs、RL大)(适用电流源) 串：Q = = (空载Q值)(LC回路Q值) QL= (要求Rs、RL小)(适用电压源),例：R=10K，L=1mH，C=0.1uF，is= 求：0、Q、Z0、BW u、iR、iL、iC 解： 0 = = = rad/s Q =0CR= =100 = =0L = =100 Z0 = R =10K ，BW = = rad/s,L,C,R,.,0 =0 = rad/s (并谐) ，U0 = Is Z0 = 30(V) IR0 =Is = 30(mA) ，IC0 = jQIs = 120(A) IL0 = -jQIs = -60(A) u0(t) = (V) iR0(t) = (mA) iC0(t) = (A) iL0(t) = (A),.,.,.,.,.,.,.,.,例：Is=10mA、L=100uH、R=10、C=400pF、 RL=100K，求谐振时R0、U0、IL、BW 解： 0 = = = rad/s Q= = = =50 (空载Q值) Z0 = = = 25K Req =R0RL = = 20K,jL,R,RL,U0 = IsReq = = 200 (V) QL = Qeq =0CReq = = = 40 BW = = = rad/s IL = QL Is = = 0.4 A,jL,R,RL,例：L=100uH、C=100pF、Q=50、Us =150V、Rs =25K， 求0、I0、U0、IL 解： 0 = = = rad/s R0 = = = 50K Req =R0Rs = = 16.7K Is = = = 6 mA U0 = IsReq = = 100 (V),C,Rs,L,I0 = Is = 2 mA IL = QL Is = Q I0=100 mA,C,Rs,R0,L,例：串谐的等效电路 Z=jX= X=0 0= ，Z0=0 并谐的等效电路 Y= = =jB B=0 0= ，Z0= =,jL,Z ,jL,Z ,例：Q=100 (空载)，N=100T，L=400uF，C=100pF， Rs=8K，使并谐电路获最大功率，抽头N1=？ 解：Rs= ，m= Q= r= = = =20,R,C,L,is,Rs,R= 匹配： = = = = m= = N1 = =20T,例：谐振时IRL=15A、I=9A，求IC 解：谐振时U和I同相，IRL滞后U角L，IC超前U90角 I=IRL+IC I=IRLcosL ，cosL= = = ，L=53.1 IC=IRLsinL=15sin53.1=15 =12A 或IC= = =12A,.,.,.,.,.,.,.,.,.,r,C,L,+1,+j,U=Uu ，I=Ii i=u =u-i=0 cos=1