IEEE 25- Experimental Verification of Current Source Inverter with ZVS Commutation Circuit


This paper presents a current source inverter
suitable for high voltage and high power motor drives. This
inverter uses thyristors as main switching devices and utilizes
ZVS commutation circuit. Compared with conventional load
commutated inverter, the proposed inverter has advantages of
good power factor and capability of self-starting. In this paper, a
test model of the proposed inverter was evaluated. We verified
that the test inverter model operates with power factor 1. And it
is possible to start the inverter even if motor speed is 0. Moreover,
synchronous motor with 2 windings was driven by 2 proposed
inverter. As a result, it was confirmed to be able to decrease
torque ripple of the motor and harmonic component of voltage
source. In addition, the operation of ZVS commutation circuit
was evaluated by simulation and experiment. As a result, it was
verified turn-off loss mainly depends on inductance of ZVS
commutation circuit, and doesn't depend on gate resistance.
Moreover, when switching device turns off the current, the
voltage of the switching device is almost 0V. That is, even if the
inductance is large, the peak voltage of the switching device is low,
and the loss is small. Therefore, ZVS commutation circuit can be
easily composed because the circuit need not be made low
inductance. From these results, a large capacity drive system can
be easily offered by using the proposed circuit.