Blog for students taking ECEN5817 Resonant and Soft Switching Techniques in Power Electronics, ECEE Department, University of Colorado at Boulder, Spring 2012
Vs1=Voc=4*Vg/pi Zi0(s)=Zo0(s)=s*L+1/(s*C) Isc=1.33A=Vs1/||Zi0(jws0)|| f0=100KHz=1/(2*pi*sqrt(L*C)) L and C can be found from the last two equations: L=.798mH; C=3.174nF
I did what you did but I got 0.21 two ways. I plotted H(jw) (the function for a series resonant tank is in the text). My resolution around 110e3 was very fine.....and I calculated slopes. My slope at fso was 3.483e-5 then multiply by 2pi*km.
If you do it analytically (with Matlab's symbolic toolbox or whatever), I obtain the same answer.
Has anyone calculated Qenv and wenv? I get around 2 and 7.1e4. Can anyone verify?
Looking at your answer for Genv(0), it seems we are differ by multiplication of 2*pi.
Your slope of dH(jw)/dfso is 3.483e-5. My slope is for dH(jws)/dws is 5.54e-6. The key different is you differentiate w.r.t f, but mine is ws. In that case, I believe your formula supposed to be: Genv(0) = dH(jw)/dfso * km (omit 2*pi) or if you differentiate w.r.t ws like me, it will be: Genv(0) = dH(jw)/dws * 2 * pi * km Then, our answer will agree.
Genv(0)=Km*Vs1*d||H(j*2*pi*f)||/df (at f=fso) Evaluating the units: Genv(0) is unitless Km units: Hz/V Vs1 units: V d||H(j*2*pi*f)||/df units: 1/Hz Total: 1=(Hz/V)*(V)*(1/Hz)
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12 comments:
Nope. I get 1.8nF and 1.4mH. Doesn't mean I'm right.
Vs1=Voc=4*Vg/pi
Zi0(s)=Zo0(s)=s*L+1/(s*C)
Isc=1.33A=Vs1/||Zi0(jws0)||
f0=100KHz=1/(2*pi*sqrt(L*C))
L and C can be found from the last two equations: L=.798mH; C=3.174nF
I have the same equations but am getting the values I wrote above. Just to double check is the
||Zi0||=||Zo0||=(1-wo^2LC)/woC?
I think I figured out my mistake. ||Zi0|| has to be evluated at ws0 not w0.
I get L=0.798 mH and C=3.174 nF too. However, my steady state Genv (Genv(0)) is very small 0.0348.
Genv(0) = abs(dH(ws)/dws) * 2 * pi * Km
My problem is dH(ws)/dws) evaluated ws=wso is so small, its value is 5.54e-6. Does anybody found it this way too ?
I agree with Tanto and Vojkan.....I haven't yet evaluated Genv(0).
Tanto,
I did what you did but I got 0.21 two ways. I plotted H(jw) (the function for a series resonant tank is in the text). My resolution around 110e3 was very fine.....and I calculated slopes. My slope at fso was 3.483e-5 then multiply by 2pi*km.
If you do it analytically (with Matlab's symbolic toolbox or whatever), I obtain the same answer.
Has anyone calculated Qenv and wenv? I get around 2 and 7.1e4. Can anyone verify?
I got woenv=8.73e4 & Q=1.45. Close enough. Maybe slight error due to approximations.
Hello Brandon,
Looking at your answer for Genv(0), it seems we are differ by multiplication of 2*pi.
Your slope of dH(jw)/dfso is 3.483e-5. My slope
is for dH(jws)/dws is 5.54e-6. The key different is you differentiate w.r.t f, but mine is ws.
In that case, I believe your formula supposed to be:
Genv(0) = dH(jw)/dfso * km (omit 2*pi)
or if you differentiate w.r.t ws like me, it will be:
Genv(0) = dH(jw)/dws * 2 * pi * km
Then, our answer will agree.
I get Qenv = 1.102 and woenv = 69264.4.
Tanto,
I agree with your results.
Genv(0)=Km*Vs1*d||H(j*2*pi*f)||/df (at f=fso)
Evaluating the units:
Genv(0) is unitless
Km units: Hz/V
Vs1 units: V
d||H(j*2*pi*f)||/df units: 1/Hz
Total: 1=(Hz/V)*(V)*(1/Hz)
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