EEE G545Control & Instrumentation of Power Electronic SystemsComprehensive Examination, 2008Marks:40(Open Book)Time:3 hours______________________________________________________________________________1.A DC-DC buck converter with the circuit modelled completely with switch ON state resistance rS, diode ONstate drop VDand resistance rD, inductance Land with stray resistance rL, output capacitor C, and load resistanceRo, has a small perturbation state equation given byddt±iL±vc=[−DrS−(1−D)rD−rL]/L−1/L1/C1/(RoC)±iL±vc+D/L[−rS+rD]iL/L+[Vin+VD]/L00±Vin±D(This is similar to the derivation of equation (16.40) of the text, starting from the circuit of Fig. 16.4, except thatthe resistance in series with the output capacitor has been assumed to be zero.) Considering the entire range ofduty cycle Dand load resistance Ro, what are the extreme possible locations of open-loop poles for the setup?....(10)2.A certain three phase, switch-mode inverter is to be operated from a DC link of voltage Vdusing pseudovectorcontrol of a certain frequency. If the output AC rms is to be some
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iL, marginal stability condition, stray resistance rL, state resistance rS, load resistance Ro