GB1296043A - - Google Patents

Abstract

1296043 Inverting MITSUBISHI DENKI KK 2 Dec 1969 [2 Dec 1968 14 Dec 1968 26 Dec 1968 3 Feb 1969 (2) 19 Feb 1969 21 July 1969] 58882/69 Heading H2F [Also in Division H1] An inverter comprises at least two thyristors 2a, 2b connected in series with a winding 1a2, 1b1 of a saturable reactor between the D.C. terminals PN and the output terminal O so as to reduce the charge and discharge times of the commutating capacitors 3a, 3b through reactors 7a, 7b. Thyristors 2a, 2b are triggered alternately by means not shown, so as to connect alternate sides of the D.C. power supply Ed to the output terminal O via the two windings of the saturable transformers 1a, 1b. Each time a thyristor is turned on, the appropriate commutating capacitor becomes discharged at a frequency determined by inductor 7a, 7b into the previously conductive thyristor. In their non-saturated state, the windings of transformers 1a, 1b minimize the current in the commutating capacitors 3a, 3b, but when saturated provide negligible impedance in the load circuit. In Fig. 21 (not shown), a damping diode and resistor are connected between the cathode of thyristor 2a and the anode of 2b. Figs. 2, 5, 7, 22 (not shown), utilize the thyristors to switch one side of a D.C. power supply alternately to opposite ends of the primary of a double-wound transformer. In Fig. 13, a non-saturated commutating transformer 8 is employed together with saturable inductors la, 1b. The saturable inductors and commutating transformer may be wound on the same core (Figs. 24-28, see Division H1). Figs. 5, 6, 10, 11 relate to bridge arrangements for four thyristors. High frequency pulse width modulation may be employed. The load may be connected between terminal O and one of the supply terminals in a D.C.-D.C. converter.