ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 1 Lecture 23

Steady state solution of state planeTwo possible trajectories for given M and J

ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 9 Lecture 23

Two possible trajectories for given M and J

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

Two possible trajectories for given M and J

ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 11 Lecture 23

Steady state solution of state planeSolve for initial conditions Mc0 and JL0

ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 12 Lecture 23

CCM output plane characteristics

ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 13 Lecture 23

Why all diodes become forward-biased

Capacitor current waveform explanation

CCM near DCVM boundary

ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 14 Lecture 23

State plane trajectory: DCVM

As predicted by CCM analysis

DCVM trajectory

DCVM occurs when

ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 15 Lecture 23

Discontinuous conduction mode(DCVM)

• Occurs at heavy load and low output voltage

• During the “discontinuous” interval, all four output diodes are forward-biased

• The capacitor voltage waveform exhibits an additional subinterval with vc = 0

ECEN 5817 Resonant and Soft-Switching Techniques in Power Electronics 16 Lecture 23

DCVM solution

Mode boundary

Steady-state solution

Output characteristicsSolid lines: CCMDashed lines: DCVM