To explain important choices to be made when planning the installation, reconfiguration and uprating of electrical power systems in critical offshore oil and gas facilities.
Protection relays implementing the IEC61850 protocol have become pervasive in both utility and industrial electric power systems as a result of their ability to provide greater electric power reliability and system visibility and reporting while also reducing the space and weight previously required for both equipment and cabling needed to implement offshore power automation systems.
The paper combines experiences from power system automation engineers working for a number of international organisations on oil and gas projects worldwide, together with information from electrical utility engineers working in North America.
Traditionally offshore installations around the world have relied upon load or power management systems (LMS / PMS) or electrical network management and control systems (ENMCS) to provide both automatic control of generators and load feeders with visualisation and situational awareness. The latest generations of these systems replace much of the plant wiring which was previously used to bring signals into the control system with Ethernet based data links that allow intelligence to be moved very close to the plant so that communicated data can be verified in real time.
The electrical power needs of typical offshore oil installations evolve over years to accommodate changes in plant use as oil reserve levels start to deplete and as new developments allow for introduction of improved management techniques. Such power system evolutions or upgrades can include, but are not limited to, uprating of turbine-generator sets, removal of obsolete equipment, installation of subsea power cables, installation of new sea water injection equipment and replacement of thruster motors on floating installations.
The paper includes descriptions of the challenges encountered on a brownfield project where a number of generations of generator technology needed to be integrated into an updated power system with a new control system. The steps taken to validate the new project specific logic using a real time simulation system are described. The paper includes an explanation on the use of standardised hardware and logic modules to ensure that future setting and configuration changes can be made when required with confidence.
While electrical automation systems using IEC61850 based protection relays provide great benefits for improved electrical power system integrity and maintenance, it is necessary to plan the configuration design, factory testing and the putting into service of such systems very carefully to fully realize those benefits.
Procedures for putting into service IEC61850 based electrical control systems, currently under development by IEEE power system relaying committee, are presented and compared with developing oil and gas industry best practice.