Current limiting interruption of currents at high voltages |
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| 申请号 | US3737724D | 申请日 | 1971-08-05 | 公开(公告)号 | US3737724A | 公开(公告)日 | 1973-06-05 |
| 申请人 | KIND D; | 发明人 | SALGE J; HARTEL H; | ||||
| 摘要 | An improved circuit for the current limiting interruption of alternating or direct currents in a power main at high voltages of the type wherein an energy absorbing circuit and a capacitor are each connected in parallel with a circuit path including a commutation or interrupter switch so that upon opening of the switch the current flowing therein will be commutated into the parallelly connected circuits wherein the current will be reduced to a residual value which is switched off by a subsequently connected circuit breaker. A further commutating switch is connected in series with the first mentioned commutation switch and an ohmic resistance connected in parallel therewith so that the total series resistance of the ohmic resistance and the arc resistance of the first mentioned commutation switch will be sufficient to cause the commutation of the main current into the energy absorbing and capacitor circuits. | ||||||
| 权利要求 | 1. In a method for the current limiting interruption of direct and alternating currents flowing in a power main at high voltages in which the current to be switched off is forced to commutate via the opening of a commutating switch into auxiliary parallelly connected circuit paths having a high resistance so that the current is reduced in the auxiliary paths to a residual value which is switched off by a subsequently connected circuit breaker, the improvement comprising temporarily commutating the current flowing through said switch into a circuit path including an ohmic resistor connected in series with said commutating switch (S2) prior to the commutation thereof into said parallelly connected auxiliary circuit paths. 2. In a circuit arrangement for the current limiting interruption of direct and alternating currents flowing in a power main at high voltage having a first commutation switch which carries the current to be switched off connected in a circuit path in series with the poWer main and a highly resistive energy absorbing circuit, including a resistor or an inductance, connected in parallel with said circuit path, so that the opening of said first switch will cause the commutation of the current to be switched off to said energy absorbing circuit wherein it is reduced to a residual value which is switched off by a circuit breaker subsequently connected in the power main, the improvement comprising: a second commutation switch which also carries the current to be switched off connected in said circuit path in series with said first switch; and an ohmic resistance connected in series with said first commutation switch and in parallel with said second commutation switch whereby upon opening of said second commutation switch, the current to be switched off is temporarily commutated through said resistance thereby connecting same in series with the arc resistance of said first commutation switch. 3. The circuit arrangement defined in claim 2 including an auxiliary switch, which is responsive to the arc voltage across said second commutation switch, connected in series with said ohmic resistance. 4. The circuit arrangement defined in claim 2 including a further circuit connected in parallel with said circuit path, said further circuit including the series connection of an auxiliary switch responsive to the arc voltage of said first commutation switch, a first capacitor, and a leakage inductance. 5. The circuit arrangement defined in claim 3 wherein said ohmic resistance is a wire which explodes upon being heated for a few milliseconds by a predetermined value of current passing therethrough. 6. The circuit arrangement defined in claim 4 including a further commutating switch connected in said circuit path in series with said first and second commutation switches, and a further ohmic resistance connected in parallel with said further commutation switch; each of said ohmic resistances being in the form of a wire which explodes upon being heated for a few milliseconds by a predetermined value of current passing therethrough, with each of said wires being dimensioned to explode for a different current value. 7. The circuit arrangement defined in claim 4 further including an additional circuit means for aiding in the temporary commutation of the current through said ohmic resistance; said additional circuit means consisting of the series connection of an auxiliary switch responsive to the arc voltage of said second commutating switch, a further capacitor having a large capacitance but a low rated voltage compared to the mains voltage, and a leakage inductance, and being connected in parallel with said second commutating switch; said auxiliary switch being of the type which prevents a discharge of said further capacitor through the circuit path formed by said first capacitor, said leakage inductance and said first commutation switch upon completion of the commutation of the current to said ohmic resistance. 8. The circuit arrangement defined in claim 7 wherein said ohmic resistance is a resistor having a constant value of resistance. 9. The circuit arrangement defined in claim 7 wherein said ohmic resistance is a resistor whose resistance value is current dependent. 10. The circuit arrangement defined in claim 7 wherein said auxiliary switch is either a wiper switch, a triggered spark path, a switch or a spark path with a subsequently connected diode, or a thyristor. 11. A circuit arrangement including a plurality of the circuit arrangements as defined in claim 2 connected in series so that the residual current can be reduced to any desired low value. 12. The circuit arrangement defined in claim 2 wherein said commutating switches are terminals or partial arcs of a single switch. |
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