| Abstract |
With the development of power transistors and GTOs, the traditional thyristor and the associated pulse-commutation circuits are being replaced. However, the high turn-off losses of these devices have been an incentive for the development of new resonant circuits on one side and for its application with an additional commutation circuit on the other side. Thus, the voltage is applied to the device after its switching-off, therefore with very low turn-off losses. So, the pulse-commutation configurations known from the thyristor circuits have as a new purpose not to assure the turn-off time of the thyristors, but to permit a zero-voltage switching. The commutation circuits are now analyzed from a new point of view, considering high switching frequency, low switching losses and times, and low cost. It is shown, that DC-side commutated inverter circuits, earlier only used with low switching frequency, can present lower switching losses, cost and volume, especially with high switching frequencies. A comparative study of different DC-side commutated circuits is presented together with a control method which minimizes the switching losses in the inverter. |
