steady state condition in the half bridge situation

Is the steady state for current that it reaches zero or IL0. If IL0 I just dont see how this state plane can be drawn beacuse of the current changing from -IL0 to +IL0?

Expression for PIV-eliminating IF

Do you guys get the radius as JF? Then PIV=1+JF= 1+IF/(nVg) sqrt(Ll/Cd). I am not having any luck in eliminating L and somehow expr.essing it in terms of Qr

HW 6 ZVS in bridge

In this problem, I think that on the turn off of Q2 the voltage vs goes up from 0 to V_bus and then overshoots and starts ringing. At this point (t_c) we have Q1 and D1 both on. This creates a parallel LC circuit, and when I try to solve Ldi/dt = V_bus = w_0 L dj/dtheta V_bus/R_0 I get that dj/dtheta = 1 which doesn't make sense to me for the circle. Am I misunderstanding the behavior of the circuit at this time?

Also, for the initial condition, can we assume that this is a small enough amount of time that i_L stay steady at -I_L0 for the entire time it is charging the capacitors to get v_s up to V_bus?

State plane plot for forward converter problem

If I understand this correctly, in the case of the forward converter the state plane diagram will look a lot like the very initial problem we did in class (the one with the current src in parallel with the capacitor) except because of -ve sign on nVg which I took as Vbase, it'll be in the second quadrant.

HW6 Reverse Recovery of Freewheeling Diode

I normalized vd and il to put in a state plane diagram. I have an id/Ibase term in my dm/d_theta equation. What do I do with this? I can't make j = (il-id)/Ibase because that would affect my dj/d_theta equation.

On slide 15 of lecture 16, how did Prof. Maksimovic derive m(theta)=1+A*cos(theta + theta_0) and j(theta)=J-A*sin(theta+theta_0)?

Lecture 17: Determining center of circle

I am not able to understand how the professor determined the center of the circle for the buck example by inspection as M. Woudn't we first have to go through the process we went through in the first few slides to first get the equation of the circle?
Thanks

Genv(0)

Has anyone figured out how to determine Genv(0) for the second problem? I was thinking.....

since vs1_hat = 2Vg*cos(pi*D/2)*d_hat..........we can say vs1_hat/d_hat *d_hat/v_hat

= 2*Vg*cos(pi*D/2)*Kpwm = vs1_hat/v_hat

But in the last homework it was more complicated with a partial derivative?

Hi every body

Hi every one

N(s+jws0), N(s-jws0) and Vs1 terms

I need to double check if is correct to choose N(s+jws0)=N(s-jws0)=R and not R(s+jws0)first term and R(s-jws0)second term. If I do it like in first case then I can get rid of 2s term.
Second, how you deal with Vs1. I am thinking Vs1=Is*Z
Z= R/(1+sRC).
Final result sanity check
Genv(s)=-Is*R^2*2*pi*km*1/(s^2+ws0^2)
Please advice.

Problem 2 Hw 4

I just wanted to confirm the transfer function used. Because if this part isn't right, the entire solution is wrong. Like the other problem its just a sanity check.

I get H(s) = R/ (1+sRC) = V/I

Can someone confirm?

Sanity check for values of L and C

Do you get 0.22nF and 11.36mH?

HW3 19.8 c: fm

Can someone please give me a hint about getting an expression for fm?

Prob 19.6 Rcrit

The problem description states that we want Rcrit to be at least 200 Ohms, but while going through steps b & c I never used this value to make any design choices. When I plug my calculations back in I get Rcrit = 175 Ohms for part d, which does not match the design. Should I have used the 200 Ohm value from the problem description in the calculations, or do I probably just have a math error somewhere?

Problem 19.9

Can someone help me compare the Voc value for part A. I used Voc=(4*Vg/pi)*n*||H_inf(s)|| and got Voc=138V. This value seems too big for Vg=12V. Maybe my formula for Voc is wrong! Anybody with the same result?

HW3 pb19.6a R_inf

R_infinity=L/(Cs||Cp) doesnt seem right.

this is second edition book, sixth printing.

I couldn find any errata that talks about this.

Thank you.

In general: tau=RC=L/R, so R=sqrt(L/C)

Conceptual Question Regarding Rcritical

We focused on the LCC resonant tank and found that if R > Rcritical, we are in ZCS mode. If R < Rcritical we are in ZVS mode.

(A) I'm not sure exactly why this is true?
(B) Is this a general statement for any converter....i.e., if R> Rcritical its in ZCS mode?