Case Studies

Electricity Network Improvement Project

7 May 2017

SCADA Improved Network Energy Management Efficiency

United Utilities plc manages and operates 60,000 kilometres of overhead lines and underground cables, and 32,000 substations. This covers an area of 12,000 square kilometres, or around 2.2 million homes in north‐west England.  It is the largest geographical region of all the UK DNOs.

The network covers a diverse range of terrain and customer mix from isolated farms in Cumbria to areas of heavy industry and dense urban population in Manchester. Despite the large areas of countryside within the north‐west, approximately 75% of the network is underground.

Both underground cables and overhead lines are utilised to distribute electricity. Underground cables supply dense urban areas, a mix of underground cables and overhead lines are used typically for smaller towns and semi‐urban areas whereas rural areas are predominantly supplied by overhead lines.

The Challenge

Like all other UK REC’s, UU plc are governed by the regulatory body of Ofgem, and have been involved in a UK de‐regulated market since 1990. The Regulator produces Distribution Price Review (XD) document every five years, which contains the targets and goals, including improved and secure customer service, and the associated reward/penalty. The previous Document XD3, and the current XD4, focus very closely on quality of supply (QoS), and provide very tight targets, against Customer Interruptions (CI) and Customer Minutes Lost (CML).

In order to maximise their return in reward, and to avoid the penalties for failing to meet these targets UU plc, like all other UK REC’s embarked on a state‐of‐the‐art Distribution Automation programme of their 11kV distribution network.

Distribution Automation is a means of providing remote‐ control at any secondary circuit breaker or switch on the network, thus providing the means of fault isolation to a particular point on the network from a remote central location. This is instead of the old traditional and time‐consuming method of visual fault location and manual switching.

This remote process of network reconfiguration allows the utility to provide a much improved service to its customers and contributes greatly to meeting the 3 minute target CI/CML set by the Regulator for minimising customer interruptions.

The Solution

In an established mature infrastructure such as the UK, before deploying any solution or equipment, a number of existing parameters have to be considered, namely:

  • Interfacing to existing legacy switchgear with no remote‐control facility
  • Ability to integrate intelligent Secondary equipment with Primary substations and Network Management Systems (NMS/DMS)
  • Existing radio and communications infrastructure with possibilities of integration with communications network used for other applications
  • Use of latest communication technologies (e.g. Radio / GSM communications coverage)
  • Protocol issues & support
  • Customer dispersion and density (rural/urban)
  • Expertise of existing staff
  • Health and Safety issues and risk assessments

In view of the above, and mindful of the need to meet regulatory targets, UU plc embarked on a companywide Electricity Network Improvement Project (ENIP).

To prove the concept initially the project started with a pilot scheme with the automation project within the South‐East Macclesfield region using the Remsdaq CallistoIES and running automation sequences within its ‘PILoT’ logic programme.

Once proven and accepted as the platform to meet UU plc needs the CallistoIES unit was chosen as the standard for UU plc’s ENIP project and initially deployed across the more hostile terrain within the Derbyshire Peak District regions of the 11kV overhead network, addressing initially its top 100 worst affected customers across the network.

The ENIP project can be considered two separate elements (a) SCADA/PMR Master Station & Communications system, and (b) RTU framework agreement.

(a) SCADA/PMR Master Station & Communications System

United Utilities already utilised an MPT1327 PMR (Private Mobile Radio) scheme on an existing Marconi backbone for its vehicle tracker system to ensure the security and whereabouts of their vehicles. Remsdaq’s Celeste Master Station software suite was initially employed as a stand‐alone Distribution Automation (DA) system to provide the Human Machine Interface (HMI) to the Control Centre operators, and the Remsdaq CallistoIES RTU equipment connected to plant on the 11kV network.

As part of the SCADA/PMR Contract the Remsdaq Celeste Suite was developed with a bespoke interface to UU plc’s Network Management System, with a Customer Relationship Management System (CRMS) interface.

This arrangement seamlessly coupled the two systems’ databases together, and provides  common information and feedback on the network conditions to the Control Centre Engineers, whilst providing a single point of   control to enable secure switching decisions on the network.

Initially, however, addressing the ‘worst affected   customers’ was paramount to UU plc. Therefore, the initial sites, some 600 off, were deployed using the Remsdaq Celeste Master station as a totally stand‐alone (DA)  system.  This DA master was integrated with Remsdaq’s CallistoIES RTUs, communicating over GSM mobile communications network, using Westermo GSM TD01 modems. The large size and hostility of the geographical terrain of the UU plc network, presented a challenging problem for coverage of the MPT1327 network.

In order to deploy the existing radio hardware and en‐sure that the coverage was effective, four strategically located Trunk System Controllers (TSC) PMR Gateways were installed at Manchester, Preston, Kendal and   Carlisle, and forty‐one radio base stations deployed across the network to maximise the coverage of the scanning nature of the PMR telemetry.  This topology gave the coverage as one effective PMR radio network with resilient communication links and  fall‐back in the event of equipment failure.

All four TSC sites were connected via the UU plc WAN OCS network using Ethernet 10/100M LAN modems, with communications to the base stations via a number of existing BT lines, microwave and X21 circuits. The main SCADA server also includes this resilient   functionality, with an identical Master Communication Unit (MCU) back‐up server located 6km from the main site and kept in synchronism with the main server using a set of SCO Linux mirrored discs that keep the database identical at all times over the UU corporate network and a dedicated 100MB ‘dark’ fibre link for resilience. Speed of response is always paramount in a system such as this. Therefore an already proven bespoke protocol developed by Remsdaq for London Power Networks was deployed on the UU plc PMR system. The  protocol optimises the times spent on the Control and The Control channel is configured for using short unique SM and SDM messages, thus retaining the Traffic channel for the longer NPD (Analogue information) transmissions. In the event of a Control channel failure, the Traffic channel will change its function and becomes the Control channel.

(b) RTU Framework Agreement

On acceptance of the above system the CallistoIES RTU units at subsequent sites were installed and commissioned with PMR radio communications units instead of GSM modem supplied on the initial sites. The main control system retained its GSM modems for out‐bound communications, and the original GSM remotes were retained, communicating over GSM, until the need to switch to radio arises.

The CallistoIES RTU units are supplied in six different variations:

  • Ground Mount Cabinet, 1‐Switch
  • Ground Mount Cabinet, 2‐Switch
  • Ground Mount Cabinet, 3‐Switch
  • FKI GVR retrofit
  • FKI GVR new supply
  • ABI retrofit

The UU plc rural network has a large coverage into both the Lake and Peak Districts, with many kilometres of 11kV lines which, given the exposure of their location to inclement weather, are susceptible to a greater number of faults. (ABI).

The ground‐mounted urban project, whilst being easier to access, had the increased focus of a greater customer density per circuit. Interruptions and faults within the urban network can have a detrimental effect on the CI and CML targets. A standard IP54 rated outdoor ground mount enclosure was designed to meet the environment in which UU plc locate the device in this retrofit application, and allow easy connectivity to the plant and EPDL’s non‐intrusive actuator design (safety being always the prime consideration in any site work). The Remsdaq CallistoIES cabinet is designed with pad‐lockable selector switches and push‐buttons, complete with local/remote inhibit functionality.

Since the project commenced in 2003, UU plc have installed and commissioned to date over 1,500 CallistoIES units on their 11kV network, with continued work being planned in the XD4 Distribution Price Review period.

Business Benefits

The UU plc Distribution Automation Scheme provides UU with a cost effective means of offering an improved and efficient electricity supply to its large customer base.  Some of the major benefits gained from this project are:

  • Substantial improvements on Customer Minutes Lost and number of Customer Interruptions due to automation of the distribution network.  This not only reduces the utility’s losses in revenue and penalties to Ofgem, it also allows UU plc to benefit from the rewards set by the regulatory body.
  • Customer and regulator satisfaction through improved customer services.
  • Utilisation of existing communications infrastructures.
  • Relevant and cost effective use of latest communications technologies (e.g. GSM) with potential for future technological upgrades offering cost and technology advantages.
  • Resilient front end server and communications.
  • Standardised RTU equipment / build, offering economy of scale savings and allowing non‐intrusive retrofits to existing switching equipment.
  • Simplified and speedy installation and commissioning, paying special attention to safety issues.
  • Ease of RTU maintenance and support, with Remsdaq’s ‘complete lifetime support’ philosophy and on‐going evolution to meet evolving needs from its UK based offices and SCADA centre of excellence.
  • Inherent flexibility, modularity and configurability within Remsdaq’s Callisto RTU and Celeste master station provide the utility with an efficient and flexible approach to their Distribution Automation, design and implementation.
  • Future proofing of the SCADA master and RTU products.  For example, being aware of Callisto’s powerful transducerless analogue option, UU plc has already ordered its RTU units ready for this option.
  • Bespoke and standard training modules delivered by Remsdaq’s dedicated Training Department.