Three-phase zero-voltage switching (English)

  • Conference paper  /  Print

How to get this document?

Local TIB services
TIB document delivery Purchase

The purpose of this paper is to present the design details for a three-phase ac voltage controller operated in integral cycle on/off control mode, such that the SCR's are turned on and off at the zero-crossing points of the line voltages. The features of the controller are: 1) zero-voltage switching for all three phases, 2) no operating restriction on the type of load and its wiring connection, 3) steady state balancing of the three phases through sequential synchronization, and 4) output power control through power regulating loop. The controller was implemented in a 250 kW resistive heating application. The oerating characteristics of the system obtained from prototype test results are included. The design details of the control circuit are described along with measures taken to reduce noise sensitivity of the logic components.