P36.008: HVDC Cable and HVAC Submarine Cable Systems

Objective

Significant trends are developing in applications of high-voltage, direct-current (HVDC) cable systems for power grid integration and interconnections. Increasingly, HVDC cable systems and high-voltage, alternating-current (HVAC) submarine cable systems are being used for power transmission from remote renewable energy generation to power grids. The line distances of HVDC cable circuits are steadily increasing for both land and submarine applications. All these occurrences are being enabled by advances in HVDC cable and converter technologies. More cable manufacturers are offering HVDC cables or adding manufacturing capacity in anticipation of the growing demands. Research is needed to:

• Understand needs, trends, and technologies for HVDC system integration with existing power grids.
• Develop tools for effective designs and implementations.
• Understand failure mechanisms and demonstrate inspection, diagnostic, monitoring, and fault location methods.
• Provide guidance, develop strategies, and share practices for effective operation, inspection, and maintenance.

Engineers, designers, and managers of underground transmission can use the tools and methods developed in this project to effectively apply, operate, and maintain HVDC transmission and HVAC submarine cable technologies. Utility engineers may use the improved understanding of the HVDC and HVAC submarine cable systems to achieve effective and economical system designs and determine system ratings. Maintenance departments can deploy new fault location methods and tools to locate faults more efficiently, especially for long-distance HVDC and HVAC submarine cables.

Research Value

This research produces new understanding, methods, and tools that can assist engineers and designers apply, operate, and maintain HVDC and HVAC submarine transmission cable systems as well as extend asset life and prevent unexpected outages. For example:

• The use of the reference books, design tools, and other investigative results may lead to more effective designs and applications for power grid integration and interconnection.
• Effective inspection and monitoring of assets could lead to increased asset utilization, rapid maintenance intervention, improved reliability, and reduced repair costs.
• Better understanding of failure mechanisms and prevention procedures may result in longer asset life, reduced customer outages, and lower operating costs.

Planned 2025 Research

This project investigates and develops methods and tools for effective applications of HVDC cable and HVAC submarine cable technologies for system integration and interconnection. The project:

Analyzes and evaluates design tools for utility engineers to prepare feasibility studies and verify proposals and implementations.ls.

Assesses cable insulation materials and aging characteristics to optimize designs and extend the life of HVDC cable and HVAC submarine cable systems.

Evaluates operational practices in application of HVDC cable and HVAC submarine cable technologies, based on technical and economic benefits and increased power transfer capability requirements.

Measures condition assessment, maintenance, inspection, and fault location technologies to meet operation and maintenance requirements.

Anticipated Deliverables

Past EPRI Research on Topic