No voltage limitations
The IEC 61892 series of standards is an essential set of specifications for the offshore oil industry, also applicable to other sectors such as offshore wind systems. The series has been thoroughly brought up-to-date to take into account rapid technology changes in offshore platform electrical and electrotechnical technology, such as increased automation and the growing use of alternative sources of energy. “One of the major changes with the previous series is that we did not include any electricity voltage limitations in these standards, either for alternating current (AC) or direct current (DC). This enables platforms to be further from the shore or interconnected, via sub-sea cables,” explains Geir Bull-Njaa, the convenor of the IEC maintenance team which worked on the revision (MT 18).
The standards were revised with help from industry. “We have several members from the manufacturing sector in our team, including one expert from a major producer of electrical equipment and systems who gave us a lot of information on market requirements. We also had someone who was very aware of International Maritime Organization (IMO) requirements because he works for one of the most important operators of mobile offshore platforms”.
Specifications for energy efficiency
Environmental preservation aspects were also taken into account. “Even if they are not environmental standards per se, we were keen for the IEC 61892 series to help limit the impact of offshore platforms on the environment,” he says. In effect, a number of energy efficiency requirements are made in IEC 61892-1, the first standard of the series which specifies general requirements and conditions for mobile and fixed offshore units, some of which were not in the previous edition. They include the efficient use of generated power, the use of high efficiency motors and variable speed drives to optimize power consumption, the use of low-loss transformers and other high-power equipment, the re-use of lighting fixtures with high efficiency long-life lamps, energy optimization through the use of brake energy or waste heat recovery, as well as the establishment of an energy management system.
Renewable energy sources are also specified in one of the standards (IEC 61892-2) as they can be used to power small offshore units with low electrical consumption. Renewable sources include photovoltaic cells and wind generators, microturbines, closed cycle vapour turbines or thermoelectric generators.
The maintenance team worked closely with IEC Technical Committee 31: Equipment for explosive atmospheres. “We consulted TC 31, especially for IEC 61892-7 which deals with hazardous areas. The expertise of its members was most useful,” says Bull-Njaa.
Other IEC TCs were kept informed, such as IEC TC 99 which specifies standards for high voltage installations and IEC TC 64, which prepares standards for commercial installations. “We also liaised with IEC TC 88: Wind energy generation systems, because we did not want to infringe on their area of standardization.”
Future developments and need for new recruits
While the revised series includes seven standards, new publications or amendments to existing publications are likely to complete the list in the near future. “There is probably a requirement for a standard on batteries for offshore installations. New installations can now be powered by hybrid power plants combining big battery packs with diesel or turbine driven generators for instance. Technology is moving very fast and we are keeping abreast of the most recent developments”.
The TC would also like to recruit new experts. “We are always on the look-out. We need good general purpose electrical engineers, but with a systems outlook,” he adds. New blood is needed to meet the technology challenges of our time and keep on improving IEC TC 18 standards so that they remain a global reference for the maritime and offshore industries, as recognized by the IMO and other regulatory bodies.