Circuit breaking arrangement

A computer program product adapted to be executed in a control unit of a circuit breaking arrangement of a High Voltage Direct Current, HVDC, power transmission system, the circuit breaking arrangement being adapted to be coupled to a transmission line arranged to carry direct current for controllably effecting discontinuation of flow of direct current in the transmission line, the circuit breaking arrangement comprising:

• a current interrupter unit adapted to, when actuated, interrupt current in the transmission line;
• and
• a first resonance circuit and at least a second resonance circuit, each of the first and the at least a second resonance circuit being connected in parallel with the entire current interrupter unit and including at least one capacitor, at least one inductor and a switch element, and a current sensing unit adapted to sense at least a direction of direct current flowing into the current interrupter unit prior to actuation thereof,
• wherein the control unit is coupled to the current sensing unit and to each of the first and the at least a second resonance circuit, wherein each of the first and the at least a second resonance circuit is adapted to, upon actuation of the current interrupter unit and when the respective resonance circuit is activated, generate a resonance current superposing current of any arc generated in the current interrupter unit after actuation thereof, and wherein the first and the at least a second resonance circuit and the current interrupter unit are configured such that, at least during a predefined period immediately after actuation of the current interrupter unit, a resonance current generated by the first resonance circuit flows into the current interrupter unit from a different direction compared to a resonance current generated by the second resonance circuit,
• the computer program product comprising a non-transitory computer-readable medium carrying computer program code configured to, when executed in the control unit of the circuit breaking arrangement:
• cause the current sensing unit to sense a direction of direct current flowing into the current interrupter unit;
• cause actuation of the current interrupter unit to interrupt current in the transmission line;
• and
• based on the sensed current direction, selectively activate at least one of the first and the at least a second resonance circuit so that at least one resonance current is generated which superposes current of any arc generated in the current interrupter unit after actuation thereof, which generated at least one resonance current has an opposite direction to the sensed current direction at least during the predefined period immediately after actuation of the current interrupter unit,
• wherein the resonance current is generated upon closing of the switch element by means of successive discharging and charging of the at least one capacitor.