Hitachi Energy’s fast-track modular packaged substation service has delivered a new 11 kV substation for Total Lindsey Oil Refinery (LOR) as part of an ongoing programme to upgrade the power distribution infrastructure at the site in North Lincolnshire. Working within a tightly defined project window, Hitachi Energy designed, manufactured, delivered and commissioned a complete containerized substation, based on its compact UniGear ZS1 medium voltage (MV) switchgear.
LOR was established in the 1960s on a site five miles from the Humber River estuary and was the first UK refinery to process North Sea Oil. It is currently the country’s third largest oil refinery, processing 10 millions tons of crude per year – the equivalent of 200,000 barrels per day (bpd).
LOR’s processes require an extensive power network comprising several substations from 11 kV down to the sub-distribution level of 415 V. The site is currently carrying out a substantial replacement programme to bring its 11 kV and 3.3 kV switchgear assets up to the latest performance, reliability and safety standards.
A key element in the upgrade programme was the replacement of the strategic 1A/2B 11 kV substation that acts as a main power distribution hub for the site.
A fast-track solution was required to enable the work to be completed within the tightly defined 32-week window offered by a planned ‘T&I’ (Turnaround and Inspection) outage. Both the short timescale and space constraints at the selected location - right in the heart of the refinery - made it difficult to build a new substation building, especially in carrying out the substantial civil works to meet blast rating requirements.
Hitachi Energy offered the ideal alternative in the form of a containerized substation in a blast rated enclosure, delivered ready to ‘plug and play’ and installed on deep piled foundations to withstand blast shockwaves.
UniGear ZS1 switchgear
The containerized substation comprises 26 panels of Hitachi Energy’s UniGear ZS1 MV (medium voltage) switchgear. The compact design of this 50 kA fault rated switchgear, including front cable access, has enabled it to be configured as two front facing rows – 1 x 14 panel board and 1 x 12 panel board – joined via a low-level bus-trunking link.
The unique design of the UniGear panels meant that they could be positioned 100 mm away from the internal wall. Yet the slimline design still enabled the thick blast-proof container walls, two rows of panels and a central walkway to be accommodated within the maximum 6 metre width allowed for standard containers to be transported on the UK roads.
The ability to fit the entire packaged substation within the footprint of a single container was crucial in ensuring the ease of handling and installation of the substation solution. If two containers had been required then not only would the installation have been more complex, there would have been considerable challenges in ensuring the blast-proof integrity of the completed substation.
REA arc flash protection
A further vital factor in the compact design was the use of Hitachi Energy’s innovative REA arc-flash protection system that effectively eliminated the need for a conventional, and space consuming, high impedance bus-zone protection scheme.
The REA system uses Hitachi Energy’s class leading fibre optic light sensing and high speed fast switching techniques to continuously monitor key areas of the switchboard and, if the light from a developing arc fault is detected, it will trip the incoming breaker in less than 2.5 ms. This rapid interruption of the fault current removes the incidental energy in as short a time as possible, preventing the arc from causing damage or creating safety issues.
Relion future-proof relays
The innovation in the LOR compact substation project continued with the use of Hitachi Energy’s Relion Protection and Control family IEDs (Intelligent Electronic Devices) to provide a future-proof relay solution for a variety of demanding functional requirements including generator protection, feeder protection, transformer protection and line differential protection. Initially the Relion protection and control IEDs are operating on the Modbus protocol.
An important advantage of the Relion family IEDs is that, although they can operate via fibre optic links in new build substations, they are also ideally suited for retrofit installations where they can utilize existing copper pilot cables via a modem link. Preparatory site tests carried out by Hitachi Energy prior to the contract award confirmed this communication capability at the LOR site, even over the worst case (longest) route.
RTU560 remote terminal unit
To complete the substation communications solution, Hitachi Energy supplied its RTU560 remote terminal unit to meet all of LOR’s local HMI (Human Machine Interface) requirements by enabling the new substation to be integrated within the previously localized 11 kV site network, and to access equipment remotely which had not previously been possible,
The switchgear, REA arc flash protection system, IEDs and RTUs are housed in the single factory-fitted container complete with back-up batteries.
New project for Substation 16
Following on from the success of Substation 1A/2B, Hitachi Energy is now working on Substation 16 that will provide a new power intake connection from Northern Powergrid for the LOR site, as well as the connection for the main 40 MW back-up generator. This has essentially the same scope in terms of design, delivery, installation and commission of the complete substation solution, but due to its non-critical location will be installed in a conventional substation building.
Substation 16 will feature 3150 A busbars, and an uprated version of the UniGear ZS1, rated at up to 4000 A and 50 kA fault current will be installed. The switchgear is a withdrawable pattern design that features Hitachi Energy’s well proven VD4 vacuum circuit breakers.
The Relion IEDs will be fitted that will enable Substation 16 to utilize the full inbuilt capability of the latest IEC 61850 communications standard for substations.