Reliability-Based Planning of Cable Layout for Offshore Wind Farm Electrical Collector System Considering Post-Fault Network Reconfiguration

TL;DR

This work tackles reliability-based planning of offshore wind farm electrical collector systems (ECS) by formulating a two-stage stochastic MILP that minimizes $C_{INV}+C_{O\&M}+C_{REL}$ under wind and fault uncertainties, without restricting the ECS topology to radial or ring structures. It introduces a divide-and-conquer framework for dimension reduction and a customized progressive contingency incorporation (CPCI) algorithm, which, integrated with Benders decomposition, selectively enforces contingencies and guarantees convergence under a complete incorporation condition. Case studies on multiple real OWFs demonstrate that the topology-free ECS planning can achieve roughly 20% total-cost savings relative to traditional structures and substantially reduce wind curtailment through optimal post-fault reconfiguration and OSS coordination, with CPCI consistently outperforming alternative solution frameworks in speed and robustness. The study also discusses extensions to multi-fault scenarios and cable-type selection, outlining future directions toward more general and robust optimization under practical constraints. All mathematical notation is presented with proper delimiters $...$, and the approach emphasizes exact optimization with scalable techniques for large-scale offshore wind farms.

Abstract

The electrical collector system (ECS) plays a crucial role in determining the performance of offshore wind farms (OWFs). Existing research has predominantly restricted ECS cable layouts to conventional radial or ring structures and employed graph theory heuristics for solutions. However, both economic efficiency and reliability of the OWFs heavily depend on their ECS structure, and the optimal ECS cable layout often deviates from typical configurations. In this context, this paper introduces a novel reliability-based ECS cable layout planning method for large-scale OWFs, employing a two-stage stochastic programming approach to address uncertainties of wind power and contingencies. To enhance reliability, the model incorporates optimal post-fault network reconfiguration strategies by adjusting wind turbine power supply paths through link cables. To tackle computation challenges arising from numerous contingency scenarios, a customized progressive contingency incorporation (CPCI) framework is developed to solve the model with higher efficiency by iteratively identifying non-trivial scenarios and solving the simplified problems. The convergence and optimality are theoretically proven. Numerical tests on several real-world OWFs validate the necessity of fully optimizing ECS structures and demonstrate the efficiency of the CPCI algorithm.

Figures (11)

• Figure 1: Framework of the proposed ECS planning methodology.
• Figure 2: Illustration of ECS post-fault network reconfiguration process.
• Figure 3: Illustration of OWF partition and candidate cables generation.
• Figure 4: The illustrative diagram of the CPCI algorithm.
• Figure 5: 30-WT ECS cable layout planning results.