The Reactive Compensation Optimization Configuration Scheme for Offshore Wind Farm AC Transmission System

For offshore wind farms connected by long-distance high-voltage AC submarine cables, a significant surplus of charging power occurs in the cables as the transmission distance increases, making it difficult to achieve local balance of reactive power, and thus causing overvoltage and overcurrent. To address the above issues, this paper proposes a dynamic reactive power compensation configuration scheme of static var generators (SVG) and high-voltage parallel reactors devices. The locations and capacity ranges for high-voltage parallel reactors are determined based on relevant standards for offshore wind power integration and principles of reactive power configuration. The SVG is configurated to ensure that the reactive power exchange at the grid connection point between the wind power system and the onshore AC network is zero. The paper presents an optimized configuration method for reactive power compensation for offshore wind power, which optimizes the economic performance of the reactive power devices while adhering to the constraints of voltage/current limits along the cables. Using a specific domestic project as a case study, the recommended reactive power configuration scheme was calculated and simulation analyses verified that the proposed scheme meets the requirements for overvoltage control and voltage/current limits along the submarine cables, while also satisfying the reactive power demands of the wind farm.