ECEN5817 Lecture 5•On-campus students: turn in HW1AnnouncementsOncampus students: turn in HW1• Off-campus students turn in HW1 via D2L (link on the course website); grace period ends 5pm Friday, Feb.3 • HW2 (3 textbook problems from Chapter 19) is due Monday, Feb.6. The grace period for off-campus students ends 5pm Monday, Feb.13ECEN 58171Section 19.1: modeling based on sinusoidal approximation Transfer functionH(s)A resonant dc-dc converter:iR(t)+H(s)+is(t)dc+LCsi(t)vR(t)–+–Rv(t)–dcsourcevg(t)vs(t)–sNSNTNRNFResonant tank networkSwitch networkNSNTRectifier networkNRNFLow-passfilternetworkdcloadIf tank responds primarily to fundamental component of switch network output voltage waveform, then harmonics can be neglectedECEN 5817219.1.4 Solution of convertervoltage conversion ratio M = V/VgECEN 5817319.2 Examples19.2.1 Series resonant converterECEN 58174Model: series resonant converterECEN 58175Construction of Zi– resonant (high Q) caseC = 0.1 μF, L = 1 mH, Re= 10 ΩECEN 58176Construction of H = V / Vg– resonant (high Q) caseC = 0.1 μF, L = 1 mH, Re= 10 ΩECEN 58177Series resonant converter: DC conversion ratioECEN 5817819.2.2 Subharmonic modes of the SRCExample: excitation of tank by third harmonic of yswitching frequencyCan now approximate vs(t) by its third harmonic:Result of analysis:ECEN 58179SRC DC conversion ratio MSubharmonic modesECEN 58171019.2.3 Parallel resonant dc-dc converterDiffers from series resonant converter as follows:Different tank networkRectifier is driven by sinusoidal voltage and is connected toRectifier is driven by sinusoidal voltage, and is connected to inductive-input low-pass filterNeed a new model for rectifier and filter networksECEN 581711Model of uncontrolled rectifierwith inductive filter network – input portFundamental component of iR(t):ECEN 581712Model of uncontrolled rectifierwith inductive filter network – output portOutput inductor volt second balance: dc voltage is equal to average ggrectified tank output voltageECEN 581713Effective resistance ReECEN 581714Equivalent circuit model of uncontrolled rectifierwith inductive filter networkOutput port modeled as a dependent voltage source based on rectified tank voltage, in contrast to SRC where output port is modeled as dependent current source based on rectified tank currentECEN 581715pEquivalent circuit modelParallel resonant dc-dc converterECEN