Protecting an operation control unit connected to an electric machine via a long cable
AssigneeABB AB
InventorsKnut Rongve, Tor-Odd Ronhovd
Life of this patent
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Abstract
A system for operating an electric machine and a method for protecting an operation control unit in such a system. The system includes an operation control unit, an alternating current cable connecting the machine with the operation control unit and an electric short-circuiting arrangement. This arrangement is connected to terminals of the operation control unit facing the cable and short circuits these terminals based on a detected overvoltage.
Claims20
A system for operating an electric machine comprising:
- an operation control unit controlling operation of the machine,
- an alternating current cable connecting the machine with the operation control unit, which alternating current cable is more than 10 kilometers long, and
- an electric short-circuiting arrangement adapted to protect the operation control unit, said arrangement connected to terminals of the operation control unit facing the cable, said arrangement being configured to short circuit said terminals based on an overvoltage detected at said terminals.
A method for protecting an operation control unit in a system for operating an electric machine,
- the system having
- an alternating current cable connecting the machine with the operation control unit, which alternating current cable is more than 10 kilometers long, and
- an electric short-circuiting arrangement connected to terminals of the operation control unit facing the cable, said arrangement being configured to short circuit said terminals based on an overvoltage,
- the method comprising the steps of:
- detecting an overvoltage at the terminals of the operation control unit facing the alternating current cable leading to the electric machine, and
- short-circuiting the terminals based on the detected overvoltage.
A system for operating an electric machine comprising:
- an operation control unit controlling operation of the machine,
- an alternating current cable connecting the machine with the operation control unit, and
- an electric short-circuiting arrangement,
- wherein the short-circuiting arrangement comprises a diode bridge connected to terminals of the operation control unit,
- wherein the short-circuit arrangement comprises a switch which is a thyristor connected for short-circuiting the diode bridge and a short-circuiting control unit for actuating the switch,
- wherein the switch has a gate and is configured to be closed based on a voltage on the gate,
- wherein the short-circuiting control unit has two input terminals connected to two ends of the bridge legs, one connected to one side of the bridge legs and the other connected to an opposite side,
- wherein the short-circuiting control unit has a control signal output, which provides the control signal that actuates the switch based on the detected DC voltage across the diode bridge legs and which control signal output is connected to the gate of the thyristor,
- wherein the alternating current cable is more than 10 kilometers long, and wherein said arrangement is connected to terminals of the operation control unit facing the cable and configured to short circuit said terminals based on an overvoltage detected at said terminals.
Dependencies are inferred from the claim text.