Operating Modes of the Series Resonant Converter Lecture

Operating Modes of the Series Resonant Converter Lecture 23 Resonant and Soft-Switching Techniques in Power Electronics ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 1 Lecture 23

Next Homework Assignment Problem 1 Conventional hard-switched flyback converter Ringing caused by transformer leakage inductance Limit peak transistor voltage using a dissipative snubber circuit Analyze performance via state plane analysis ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 2 Lecture 23

Series resonant converter ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 3 Lecture 23

Discontinuous Conduction Modes In the “type k” discontinuous conduction mode, the tank rings through k complete half cycles during each half switching period. The output diode rectifiers then become reverse-biased, and remain off until the input bridge transistors switch to initiate the next half switching period. Q: Why do the diodes decide to interrupt the ringing after k half-cycles, instead of k– 1, or k+1, or. . . ? ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 4 Lecture 23

The k = 1 DCM ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 5 Lecture 23

Why the diodes become reverse-biased State-plane explanation ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 6 Lecture 23

Why the diodes become reversebiased Inductor voltage waveform explanation ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 7 Lecture 23

Summary of results k = 1 DCM M=1 J < 4/ ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 8 Lecture 23

The k = 2 DCM ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 9 Lecture 23

Charge Arguments and Averaging ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 10 Lecture 23

State Plane Diagram k = 2 DCM ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 11 Lecture 23

Summary of Results: k = 2 DCM Solution for radii Output plane characteristics ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 12 Control plane characteristics Lecture 23

19. 5 General Solution for the Steady-State Characteristics of the Series Resonant Converter Mode index k and subharmonic number ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 13 Lecture 23

Type k CCM Steady-State Solution Elliptical output characteristic with Control plane characteristic ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 14 Lecture 23

Type k CCM Waveforms Switch network output voltage Tank inductor current, odd k (ZCS) Tank inductor current, even k (ZVS) ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 15 Lecture 23

Type k DCM Steady State Solution Type k DCM, odd k Output voltage Mode boundaries Type k DCM, even k and Output current Mode boundaries and Steady-state equivalent circuit model for even DCM: an effective gyrator. The converter exhibits current source characteristics. ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 16 Lecture 23

CCM and DCM Boundaries ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 17 Lecture 23

Complete SRC Characteristics Control Plane ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 18 Lecture 23

SCR Output Characteristics Above Resonance ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 19 Lecture 23

SRC Output Characteristics Selected Modes Below Resonance ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 20 Lecture 23