Energy saving circuit for a controllable electrical valve

Abstract

Abstract 1. Energy economy circuit for a gate-controlled electric load-current valve (Th1 ; Thu , Thv , Thx , Thy ), particularly for a gate turn-off thyristor, a) including a turn-off voltage limiting capacitor (C1 ), b) an electric turn-off voltage limiting valve (D1 ) connected in series with the capacitor, c) including an energy storage choke (L1 ) for temporarily storing the energy of the turn-off voltage limiting capacitor, d) the turn-off voltage limiting capacitor (C1 ) being effectively connected to the energy storage choke (L1 ) via an auxiliary valve, characterized in that e) the turn-off voltage limiting capacitor (C1 ) and the turn-off voltage limiting valve (D1 ) are connected in parallel with the gate-controlled load-current valve (Th1 ; Thu , Thv , Thx , Thy ), the turn-off voltage limiting valve having the same polarity as the gate-controlled valve, f) the energy storage chocke (L1 ) is connected in series with a freewheeling valve (D4 ), g) energy storage choke and freewheeling valve being connected in parallel with the gate-controlled load-current valve (Th1 ; Thu , Thv , Thx , Thy ) and h) the turn-off voltage limiting capacitor (C1 ) being effectively connected to the energy storage choke (L1 ) via at least one auxiliary gate-controlled valve (BOD, Th2 ), i) the voltage drop in the current branch between the turn-off voltage limiting capacitor (C1 ) and the energy storage choke (L1 ) is greater than the voltage drop across the freewheeling valve (D4 ) and j) the gate-controlled load-current valve (Th1 ; Thu , Thv , Thx , Thy ) is turned off at the earliest when the energy stored in the turn-off voltage limiting capacitor (C1 ) has been transferred into the energy storage choke (L1 ) and the voltage across the turn-off voltage limiting capacitor (C1 ) has dropped to low values around zero.

Inventors

• 👤 Urs Zürcher

Bibliographic Details