2.1-GCL并联谐振电路ppt课件

1、13-4 GCL并联谐振电路Y(j)= = G + j( ) =|Y|() |Y| = () =NoImageC1L.NoImagetg1C1LGIL.IC.Is.IG.GjL1jCIs=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)10L.1LC1Y j()NoImageNoImage.NoImage. IL0= U0 = Is = -jQIs IC0= j0C U0 = j0C R0

2、 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 BW1j0LjR00L.R00LR0CLNoImage3.频率特性 H(j)= = = = = = H(j)= = R0 = , Is R0 = U0NoImage.1GjC1L1G11jCG1LGNoImage00CG001LG00CR00R00LQ00NoImage.NoImageNoImage.并谐: = = ()= =u-is 串谐: = = ()= =i-usNoImageNoIm

3、age.NoImagetg1Q00NoImageNoImage.NoImagetg1Q004.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)R00LR0 q0LR0 qR0QNoImage10CR0LRRsRL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 =

4、 =100 Z0 = R =10K ，BW = = rad/s10 cos 105t30 mA1LC1103107NoImageIL.IC.Is.IR.LCR+U-105107104NoImage10CNoImageNoImage.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)NoImageNoImageNoImageNoImageNoImage.1

5、00 cos105t30 10 cos 105t30 cos105t120 cos105t60 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 = = 20K1LC1104410105 106NoImageNoImage1044 101010Q2R50210NoImageIs.jLRRLNoImage+U0-. U0 = IsReq = = 200 (V) QL = Qeq =0CReq = = = 40 BW = =

6、 = rad/s IL = QL Is = = 0.4 A10 10320103ReqR0QNoImageNoImageNoImage1.25 10540 102Is.jLRRLNoImage+U0-.IL.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)1LC11041010NoImage500CNoImageNoImageNoImageNoImage6 103 16.

7、7 103 +Us -.CRsLI. I0 = Is = 2 mA IL = QL Is = Q I0=100 mANoImageIs.CRsR0I.LI0.IL.IC.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= =jL1C1LCjLZ jLZ NoImageNoImagejC1jLjC1L1LCNoImage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= = = =20N1rCLisRsNRCLisRsNoImageN

8、oImage0Lr0LQNoImage4 1041010100 R=匹配： = = = = m= = N1 = =20TNoImageNoImageNoImageNoImageRsQ2r8 1031002204 1022 101NoImage2 101100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.NoImageNoImage35NoImageNoImageNoImage. .+U-.I.IC.IRL.rCL+1+