Optimal trajectory control strategy for improved dynamic response of series resonant converter

A control strategy that improves the dynamic response of a series resonant power converter (SRC) operating above the resonant frequency and using zero voltage turn-on switches (ZVS) is discussed. The advantages of the optimal trajectory control over the existing methods are reduced stresses on the reactive and power semiconductor switching elements of the circuit and faster responses in cases of large variations of circuit operating conditions without affecting the global stability of the system. The method is based upon the graphical representation of state variables in the phase plane. The trajectory of switching points is imposed on the phase plane by the control law. This control strategy is consequently realized by controlling a quantity of energy in the resonant circuit. The simulation results in the dynamic state are analyzed under various operating conditions and experimentally verified using an SRC prototype.<>