For the existing system:

• Identify methods to limit short-circuit currents due to multiple gas turbines operating in parallel

• Prevent large-motor starting transients which cause voltage dips and potential relay miscoordination

• Study harmonic distortion from variable-frequency drives and long 13.8 kV cables

• Consider the frequency response to the sudden outage of a generator

• Address the protection challenges due to varying short circuit current and fault-limiting device response

Integration of renewable systems:

• Determine the optimal integration of wind turbines and BESS

• Achieve a 25 % renewable energy share

• Limit excess export to ≤ 5 %

• Study wind variation and load variation 

• Consider the stress on the gas turbine generators, spinning reserve and optimal battery sizing for operational stability and safety

• Payback period must be achieved in under 10 years

An existing FPSO typically uses a 100% conventional generator by a gas-powered turbine, with a peak demand of 70 MW powered by four 25 MW gas turbine generators. System voltage variations are 13.8 kV for the large capacity of the connected generators, 4.16 kV for other motors, and 0.48 kV for further sub-distribution levels.

Traditionally, FPSO power systems encounter several challenges, including transformer energization, motor starting, protection coordination, and short-circuit current limitations. Transformer energization and motor starting may result in very poor voltage, which will also affect the rest of the system. Additionally, protection coordination between multiple generators and loads is complex, requiring careful design to ensure proper fault detection and isolation. To ensure operational reliability, FPSO power systems are typically designed with an N+1 configuration, maintaining a spinning reserve to handle sudden load changes or generator failures.

By incorporating renewable energy through wind turbine generators (WTGs), the operational carbon footprint of FPSOs can be significantly reduced. The introduction of WTGs to reduce carbon emissions adds further complexity to the system. The intermittent and variable nature of wind energy affects both the power quality and the dynamic behavior of the system, making it challenging to maintain stability, manage spinning reserves, and coordinate protection schemes effectively. Several energy evaluation scenarios were identified for the WTGs over time, and the technical feasibility was studied for the proposed system. 

ETAP Power Simulator - Comprehensive electrical network design and analysis, including:

• Unified Electrical Digital Twin – To build and analyze a virtual representation of the existing and proposed updates to the electrical power system
• Load Flow Analysis
• Short Circuit Analysis
• Motor Acceleration Studies
• Transient Stability (co-simulation with PSCAD)
• Voltage Ride Through
• Protection and Coordination
• Transformer Energization

• ETAP analysis identified areas for improvement in the existing system.
• The studies ensured validation of power quality and safety compliance for the integration of WTGs and BESS for integrated renewable power generation. 
• These studies ensured the technical feasibility of the proposed system to perform its task effectively and efficiently.
• The ETAP design to operation platform will provide a smooth transition for further studies, such as time-domain load flow, and implementation of ETAP real-time solutions for optimization using ETAP Time-Domain Load Flow, ETAP SCADA and ETAP Microgrid Controller.
  

Future-Ready Power System for FPSOs to Meet Sustainability Goals

• A system was identified that provides enhanced reliability and safety by using ETAP for validation of all operating conditions
• The design met the goal of reduced carbon emissions with up to 25% renewable integration and less than 5% energy wasted
• An optimized BESS capacity was determined that would ensure spinning reserve and frequency support under high wind variability
• The engineering team implemented a faster design process thanks to the use of ETAP Digital Twin for comprehensive power system analysis, by incorporating data into ETAP from other equipment simulation and analysis tools.
• The project design can be further optimized, using the ETAP Digital Twin single platform solution for time-domain load flow and harmonic mitigation, ETAP Real Time and ETAP Microgrid Controller.