Fully digital controlled variable active-passive reactance (VAPAR)

An inductance affects the response of power circuits. For example, the current response of DC motor depends on the armature inductance. The authors have been proposed an inductance controller using variable active-passive reactance (VAPAR) in a power circuit. VAPAR needs an output filter to reduce the ripples if it is connected to the power system. The output filter may cause resonance in current and/or voltage. A resonance suppression method has been proposed by H. Funato et al. (1997). If a state feedback method is employed for this controller, the carrier frequency of the inverter must be much higher than cutoff frequency. In this paper, the fully digital control method of VAPAR is proposed using a deadbeat control method. Using the proposed method, excellent response without transient resonance is demonstrated through simulations and experiments.