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.