Method and apparatus for damping oscillations in a power system

摘要

Embodiments disclose using a pairing or pairings of terminals in a DC power system including a plurality of terminals to implement power oscillation damping (POD), where the DC power system is connectable to at least one AC power system. The active and/or reactive power of the terminals in the pairing may be controlled or modulated in a similar manner such that no power imbalance in the DC power system is created. For example, POD may be implemented by means of active and/or reactive power modulation by pairing two terminals in the DC power system) such that their active and/or reactive powers are controlled or modulated in the same or substantially the same manner or identically but with the opposite sign.

主权项

1. A method in a DC power system comprising a plurality of terminals, each terminal being coupled to at least one other terminal and configured to convey power to and/or receive power from the at least one other terminal, and each terminal being selectively controllable with respect to power conveyed from the terminal, the DC power system being connectable to at least one AC power system comprising a plurality of power generating machines, the DC power system being adapted to convey power between at least two locations in the at least one AC power system, the method comprising, on a condition that the at least one AC power system comprises at least two different regions wherein the power generating machines in the respective regions at least potentially can oscillate against each other:
determining at least one pairing of two subsets of the plurality of terminals, each subset including at least one terminal, by means of a model of dynamics of a power system representative of at least a portion of the DC power system and the at least two different regions of the at least one AC power system, where predetermined positions are representative of locations of the respective regions and the model is based on reactance between each of the plurality of terminals and the positions representative of the locations of the respective regions and the locations of the plurality of terminals relatively to the at least one AC power system; receiving a first signal indicative of at least one parameter of a power generating machine in at least one of the regions, the at least one parameter of the power generating machine governing the power generation capability of the power generating machine; and controlling power conveyed from at least one subset of the two subsets of terminals based on the first signal such that a difference between the total power output from the respective subsets of terminals complies with a selected power difference criteria, thereby damping any oscillation between the power generating machines in the respective regions.