In this dissertation, a dynamic modeling and an improved current control strategy for quantum series resonant inverter (QSRI) are newly proposed to overcome the disadvantages of conventional QSRI, and then this scheme is applied to DC motor drive. Firstly, the detailed analysis for the internal characteristics of a QSRI is presented to quarantee the four quadrant operation of output voltage and current. Using this analysis, an optimal predictive current control technique is developed. The usefulness of the proposed modeling and control techniques are verified by the computer simulations and experiments. Next, a proposed current controlled QSRI is applied to a servo amplifier for a DC motor drive. This system generates a resonant current in a series link and switching is occurred at zero crossing instants of the resonant current, so that the switching loss and electromagnetic interference (EMI) can be effectively reduced. Motor current and speed controller considering the dynamics of current controlled QSRI are designed and the overall characteristics of the system are investigated by the computer simulations and the experiments. Finally, the porposed technique and full bridge topology are extended to a single phase AC to AC converter without input filter. The proposed techniques are expected to be widely applicable to the other types of resonant link power conversion schemes.