In this thesis, resonant converter and matrix converters are modeled and analyzed with quantum transformation and circuit DQ transformation, respectively. To reduce weight and volume of the power converter, operating frequency is increased. In DC to DC converter, the PWM converters have been used predominantly stress and but the switching frequency is limited because of their switching stress and switching loss of the switching devices. Quantum resonant converters have been introduced to increase the switching frequency.
In chapter II, new control scheme named optimum quantum sequence(OQS) control which minimizes the output voltage ripple of the quantum series resonant converter(QSRC) is proposed. This control scheme is so general that it is irrelevant to the magnitudes of circuit elements as well as to the input/output voltages so far as it is operating in the continuous conduction mode(CCM). This feature is verfied by appropriate simulations.
In chapter III, new modified output voltage control scheme for the series resonant converter (SRC) is proposed. In this scheme, quantized output voltage is obtained by quantum duty control and one last unit voltage is continuously adjusted by phase angle control during a half resonant cycle period. Therefore the proposed control method offers a clue to get rid of the stepped discontinuity problem in the output voltage of quantum control without degrading the performance. Based on the steady state analysis, optimum quantum sequence having greatly reduced output voltage ripple is given.
And in AC to AC converter, the nine switch matrix converter are modeled and analyzed. Matrix converter is very simple in structure and has powerful controllability. But the practical matrix converter is far beyond the ideal matrix converter because of its complexity due to the non ideal source such as L and C reactive components. In this thesis, the analytic expressions for the voltage gain, input power factor and so on are obtained easily with the circuit DQ transformation.
In chapter IV, this paper analyzes non-ideal step down matrix converter (MC) under the control strategy proposed by Venturini using circuit DQ transformation (CDQT) technique. The non-ideal step down MC consists of L, C and switches where L and C act as current and voltage sources, respectively. Closed form solutions for the voltage gain and the input phase angle are obtained from the DQ transformed equivalent circuit.
In chapter V, static dynamic characteristics of non-ideal step up nine switch matrix converter (NSMC) under the control strategy proposed by Venturini are evaluated by the circuit DQ transformation technique. Power circuit of step up NSMC is considered using non-ideal voltage and current sources by including practical inductance and capacitance filters.
Several static and dynamic features of the converter such as steady state input/output voltage gain, input power factor and transient response are predicted and verified by the circuit DQ transformation technique and compared with the computer simulation results.
In chapter VI, conclusions and further works are provided.
In Appendices A, the effective control voltage of phase angle control is calculated and in B, the circuit transformation analysis and phasor form analyses are compared with 3φ RLC circuits. In C, circuit DQ transformed nine switch set for Venturini's modulation function is obtained.
