Current commutation circuit
AssigneeGeneral Electric Company
InventorEdward K. Howell
Life of this patent
Estimating the term…
Abstract
Load current is diverted from a circuit breaker, when it is opened, through a commutation circuit. The latter has a capacitor, inductance and solid state switch serially connected with the output of a bridge rectifier. The input of the bridge is connected across the breaker. The switch is turned on to discharge the precharged capacitor to form a current pulse, presenting an extremely low resistance across the bridge input and causing load current diversion.
Claims31
A circuit interrupter for interrupting load current flow in a power line connecting a source of electric power to a load, comprising:
- (a) a bridge rectifier having input terminals and output terminals;
- (b) pulse forming means connected in circuit with the output terminals of said bridge rectifier to form a closed loop network;
- (c) said pulse forming means, responsive to a load current interruption signal, supplying through said network a current pulse having a peak magnitude greater than the magnitude of the load current;
- (d) switching means connected in series circuit with a power line;
- (e) the input terminals of said bridge rectifier being connected in circuit with said switching means so that responsive to the current pulse the apparent resistance across said input terminals is switched from a high to a very low value and load current is diverted from the switching means to the closed loop network;
- and
- (f) said switching means being constructed to permit its being opened to interrupt load current flow therethrough subsequent to the initiation of load current diversion to the closed loop network.
A circuit interrupter for interrupting a-c load current by switching means connected in a series circuit with a source of alternating current and a load and wherein the a-c load current is diverted to a network so that minimal arcing occurs upon the opening of the switching means, the combination comprising:
- (a) switching means being adapted for connection in series circuit with the source of alternating current and the load so as to conduct a-c load current 10 to the load;
- (b) a network comprising solid state circuit means and pulse means;
- (c) said pulse means, responsive to a load current interruption signal, supplying said solid state means a current pulse having a peak magnitude greater than the magnitude of the load current, and a duration that is substantially less than the duration of a half cycle of the a-c load current;
- (d) said solid state circuit means having inputs connected in circuit with said switching means for diverting the a-c load current from said switching means to said network during the presence of the current pulse notwithstanding the instantaneous direction of the a-c load current;
- and
- (e) said switching means being opened responsive to the load current interruption signal during the duration of the current pulse.
A circuit interrupter for interrupting load current flow in a power line, comprising:
- (a) a bridge rectifier having input terminals and output terminals;
- (b) capacitance means, inductance means and gated solid state means connected in series circuit with the output terminals of the bridge rectifier;
- (c) charging means for charging said capacitance means;
- (d) means for gating on said gated solid state means in response to a load current interruption signal for discharging said capacitance means through the aforesaid series circuit;
- (e) switching means connected in series circuit with a power line;
- (f) the input terminals of said bridge rectifier being connected in circuit with said switching means to divert load current from said switching means through the aforesaid series circuit;
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- (g) means for opening said switching means subsequent to the occurrence of the load current interruption signal.
Dependencies are inferred from the claim text.