Question

QUESTION 2 (25 points) a) By using the volts-sec balance principle, the capacitor charge balance and the small voltage ripple approximation, determine the DC conversion ratio for the Watkins-Johnson converter shown in Fig. 2.1. Use the polarities shown on Fig 2.1 to do your computation. (15 pts) 2 1 + ic Va VŠR C VL + 1 2 Figure 2.1-Watkins-Johnson DC/DC Converter b) The magnetizing force produced by avoid uncontrolled converter operation, inductance saturation must be avoided. The inductance shown in Fig. 2.1 can sustain a current of 22A without reaching the saturation point. By using the following parameters, determines the maximal load current (the value of R in Fig. 2.1) to avoid the inductor core saturation. Note that magnetic saturation occurs on the instantaneous current and not the average or RMS current. Use a switching frequency of 65KHZ to do your computation. (10 pts) high current in an inductance can create saturation. To C = 55V D=0.75 C = 110uF L= 150μH

Answer 1

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