Optimal Allocation of Synchronous Condensers in Wind Dominated Power Grids

Abstract

System strength (also known as short-circuit performance) indicates the capability of a power system to recover a fault. Renewable energy integration in power grids causes replacement and retirement of synchronous generators from generation fleet, which tends to reduce system strength. As such, a pre-defined number of synchronous generators are intentionally kept online to ensure adequate system strength in some power systems (e.g. South Australia). It results in the curtailment of wind power which eventually introduces financial concerns. To mitigate this issue, synchronous condensers can be a worthwhile choice. These devices contribute to fault level and provide voltage support to enhance system strength. Since synchronous condensers are costly, the best strategy for their allocation is a major query to investigate. To address this concern, this paper proposes an optimisation algorithm to allocate synchronous condensers to enhance system strength in a wind dominated power system by taking into account the long-term economic profitability of synchronous condensers installation. System strength calculations are based on Time Domain Dynamic Simulations with dynamic models which include current saturation limit of power electronics converters of wind farms. The proposed optimisation algorithm provides the most technically as well as economically viable solution to enhance system strength by utilising synchronous condensers.