Results on hybrid control of self-oscillating resonant converters

Hybrid Control of Self-Oscillating Resonant Converters

“…Keeping in mind that any variation of σ ∈ {−1, 1} must be instantaneous, so that σ = 0, we may compute the differential equations governing the evolution of variables z := (z 1 , z 2 ) in (3). As shown in [22], the dynamics is the same for the two circuits and corresponds to the following damped oscillator…”

“…In this work we extend [22] in several important directions: first, we generalize the main theorem of [22] about the existence of the unique limit cycle and our new proof, based on a different Lyapunov argument, applies to any reference θ ∈ (0, π]. Then, while [22] only reported simulation results, we report here on the development of an experimental device implementing our feedback on a SRC architecture. Finally, since only the PRC solution was simulated in [22], we perform SRC simulations here and show desirable matching of the simulation and experimental results.…”

“…In our preliminary conference results [22], we proposed a novel unifying second-order input-dependent (or hybrid) coordinate transformation to analyze the dynamics of secondorder parallel and series resonant converters (PRC, SRC). Differently from the phasor circuit-based steady-state analysis leading to the high-order unifying models in [3], [4], our stateplane low-dimensional coordinates allow specifying a stateplane control law based on a reference input corresponding to an angle θ ∈ (0, π], identifying suitable sectors in this new hybrid coordinate system, independently of the load.…”

“…Moreover, our self-oscillation mechanism overcomes the stringent bound on the quality factor assumed in [12], [14]: our only mild requirement on the quality factor is that the dynamics of the resonant tank must be underdamped. In [22], we also discussed in depth the PRC configuration, showing a desirable dependence of the output amplitude and frequency on the reference input θ. We also proved rigorously the existence of a unique nontrivial hybrid limit cycle, but only for the specific case θ = π 2 , leaving the same result for the whole range θ ∈ (0, π] as a conjecture.…”

“…Then, while [22] only reported simulation results, we report here on the development of an experimental device implementing our feedback on a SRC architecture. Finally, since only the PRC solution was simulated in [22], we perform SRC simulations here and show desirable matching of the simulation and experimental results.…”