Study on Leveraging Wind Farm Reactive Power Potential for Uncertain Power System Reactive Power Optimization

TL;DR

This paper introduces a robust method to evaluate and utilize wind farm reactive power potential, enhancing power system security and efficiency amid uncertainties in renewable generation and loads.

Contribution

It proposes a two-stage robust linear optimization approach for evaluating wind farm reactive power potential and integrates it into system-wide reactive power optimization under uncertainty.

Findings

Wind farms can reliably provide significant reactive power even under uncertainty.

Leveraging wind farm reactive power improves system security and operational optimality.

The method is validated through case studies demonstrating effectiveness.

Abstract

This paper suggests leveraging reactive power potential (RPP) embedded in wind farms to improve power system operational safety and optimality. First, three typical RPP provision approaches are analyzed and a two-stage robust linear optimization based RPP evaluation method is proposed. This approach yields an RPP range that ensures the security of wind farm operations under any realization of uncertainty regarding the wind farm. Simplified DistFlow equations are employed here for a compromise between computational accuracy and cost. Next, an uncertain RPP-involved reactive power optimization problem is introduced, through which system operators ensure system-wide security and optimality regarding the base case and against any possible deviation caused by uncertain lumped loads and renewable generation. Steady-state models of automatic generation control and local voltage control are also captured in this uncertain reactive power optimization, which is then transformed through Soyster's method into a deterministic optimization problem that is readily solvable. Case studies have conceptually validated that even with notable uncertainty, wind farms are still a competent reactive power resource providing considerable RPP. Also, simulation confirms positive and notable improvement of leveraging wind-farm RPP on system-wide operational security and optimality, especially for power systems with high wind penetration.