Electrical Balance of Plant Approach for Offshore Wind Power Plants: A Brazilian Case Study

Abstract

Planning the construction of an offshore wind power plant involves balancing design details that affect both technical and financial viability. The electrical balance of plant is a significant part of installation costs, and modeling it can help developers optimize solutions and reduce expenses. This paper presents an approach to model the electrical balance of plant, including inter-array cable routing and sizing, the number and size of HVAC and HVDC export cables, optimized reactive power compensation, offshore and onshore equipment, and grid connection transmission line. The model also accounts for the physical dimensions and weight of offshore and onshore substation components that are significant information for planning further steps such as the constructibility and foundation. This approach is part of CPE-Offshore, software designed to support decision-making for Brazilian offshore wind farms, considering 60 Hz 138 kV and 230 kV HVAC transmission voltages. A generic 1920 MW Brazilian wind farm located 65 km from shore is used as a case study to demonstrate results for different numbers of offshore substations. Additionally, a sensitivity analysis explores reactor combinations and cost comparisons between HVAC and HVDC systems for various plant capacities and distances to the coast. The results indicate a break-even distance of up to 180 km and the most suitable combinations to be evaluated for a 60 Hz system to avoid waste of computational time. This electrical balance of plant approach can be applied to plan an offshore wind power plant in other regions worldwide.

Keywords

• Electrical balance of plant
• offshore wind power plant
• inter-array cable system
• export transmission system
• reactive power compensation
• reactor placement