ABB has developed an Integrated Control and Protection (ICP) approach that offers significant benefits for substation automation projects, both for upgrading existing schemes and for new build.
ICP uses pre-engineered, pre-tested and preapproved equipment, which enables ABB to condense the same functionality into a much smaller footprint and reduce the amount of onsite work, as well as achieve significant reductions in delivery time. ABB Substation Automation Manager, Andy Osiecki, looks at some of the challenges involved in the delivery of an ICP project.
The type-registration of standard solutions addresses the strategic challenge of providing, a standardized modular design scheme. There is also a further major strategic challenge in marrying a standardized solution to the particular requirements of a specific substation.
Several factors may affect this second strategic challenge. Many are present from the start, and some run concurrently, exponentially increasing the challenges to delivery.
During tendering, it is not logistically possible to do a detailed risk analysis of each site. There is, therefore, an inherent risk at the start of the project. There are technical and commercial components to this inherent risk, which need to be managed carefully, to ensure successful and cost-effective delivery.
Detailed below are the major challenges that ABB faced in executing NICAP (National scheme for Integrated Control and Protection) 2, an ICP contract for National Grid, after the award of the contract.
Engineering
- National Grid (NG) has an on-line repository for drawings known as the LiveLink in order to facilitate seamless interfacing of design work. However, the dynamic nature of substation refurbishment and associated site work means there are some cases when ongoing work is not fully reflected in the drawings in the repository. We bridge this gap by doing a scan of the drawings existing at the actual site, and recreating master drawings.
- In some block houses and GIS buildings, space considerations necessitate the installation of new equipment in the space occupied by old equipment, posing additional constraints in areas such as mounting and cable trunking while housing the new solution.
- It is not uncommon for ABB’s planned outage on a protection feeder to take place at the same time as another contractor’s outage on a transformer associated with the feeder. This concurrent engineering with mutual design impact requires close co-ordination between the two suppliers. We work closely with NG and other suppliers in such cases.
- Even with type registration, there is the potential for preferential engineering to suit operating practices that specific sites are accustomed to. To avoid revisiting designs, we try to get key site personnel involved as early in the design as possible.
- Some of the equipment to be refurbished has proprietary components whose functionalities need to be retained in the new installation, but which do not lend themselves to easy interfacing or replication. This requires design work-arounds addressing existing operational practices and overcoming resistance to change.
- ICP has introduced new requirements into the portfolio of solutions required. Software interlocking on triple and double busbar stations was tested and type registered on the ICP platform.
- The UK’s Construction Design Management Regulations require installation risks to be designed out as far as possible. This takes the design from a largely office-based activity into a more comprehensive risk mitigation design environment. This also necessitates design vigilance to ensure continuous improvement of the design from one outage to the next.
Manufacturing
- The tight transmission network scenario imposes constraints on the programming of circuit outages. This influences the notice that NG is able to able to give its suppliers for the start of any works. To meet equipment manufacture and delivery times under such conditions, it becomes necessary to issue manufacture packs when the design is still not complete, and modify the pack as the design progresses.
Documentation
- NG has given timescales for the submission of documentation in relation to return to service dates. Some are milestones with associated liquidated damages. With several outages running in close proximity, some of them even concurrently, this becomes a delicate balancing act. ABB has a good record in ICP, and our commissioning files have been particularly well received.
- Since the outage period is fixed and the return to service date is sacrosanct, it is vital that equipment is integrated and tested fully before shipping to site. At site, an Site Acceptance Test (SAT) is conducted to ensure readiness for installation once the outage begins. SCS databases and crosssite fibre-communication links are tested as far as possible to mitigate potential issues during the outage.
Commissioning
- From 1 Jan 2005, NG introduced a mandatory authorization (known as the TP141 authorization) aimed at ensuring acceptable standards for commissioning engineers on NG sites. The authorization process is rigorous, and there are not enough authorized engineers across the industry to support the on-going commissioning work. This poses substantial resourcing challenges; shifting and cancellation of outages, necessitating the use of non-ABB specialist engineers. ABB reduces the impact by bringing commissioning engineers on board on a longterm basis for sites with multiple outages, as well as getting non-ABB specialist engineers on board early enough for them to become familiar with ABB equipment and testing.
- A circuit under outage may be called back to service in an emergency. When an Early Return to Service (ERTS) is called, the circuit is to be returned to service with certain minimum protections, within a few hours. The possibility of an ERTS requires carefully planned staged installation or the availability of temporary protection panels. The upstream impact of this is in engineering, manufacturing and the commissioning strategy.
Resourcing
- In order to mitigate resource shortfalls, we have implemented comprehensive subcontracts for the lower end of the engineering work, with adequate ABB supervision. A knowledge of the ICP-specific process is a necessity in all the facets of the project. In-house guidance, orientation and on-the-job familiarisation are implemented to improve our in-house capabilities.
The successful return to service of several major circuits in 2007 called on ABB’s commitment to quality and safety as well as our customer focus, and demonstrated our strong capabilities to:
- execute projects successfully in a refurbishment environment
- be responsive and adopt a pragmatic approach to problems
- be flexible to address challenges proactively, working in partnership with the customer,
- sub-contractors and third parties
- deliver excellence through continuous improvement.