High-Voltage Subsea Connectors: Enabling Innovative Subsea Power Distribution Solutions

Abstract

This paper focuses on the development of the world's first high-voltage (HV) 45kV, wet-mate connector system1 qualified in accordance with the Subsea Electrical Power Standardization (SEPS) SP-1001 Penetrators and Connectors cross-operator standard. The connector is rated for water depths up to 3,000 meters and is a key enabler of numerous offshore applications, including subsea electrical power grids; independently retrievable, high-power step-down transformers for long step-out subsea gas compression; cost-effective installation of deepwater pipelines with direct electrical heating (DEH); and simplified repair of deepwater high-voltage umbilical power cores (among others). The high voltage and current rating of the connector provides the opportunity for commonality between the primary and secondary of a subsea transformer. This reduces the cost of mating tools, protective caps and test equipment, thus improving the economics of utilizing wet-mate connectors, which can often be cost-prohibitive. The paper discusses the growing need for a clear industry standard that covers the development and qualification of HV wet-mate electrical connectors. It also explores the inherent challenges of subsea electrical connectors, including long-term reliability, subsea module integration activities, and long-term effects of sea-water immersion on insulating materials. These were identified through a policy of continuous stakeholder engagement and a thorough review of 40 years of low- and medium-voltage connector design. To illustrate the benefits that HV wet-mate connectors can provide, multiple use cases are discussed, including long step-out subsea compression; deepwater pipeline DEH; and HV umbilical repair.