Grid connections

Grid connections

Connecting to the Grid

From application to energisation

What is an Independent Connection Provider (ICP)?

ICP stands for Independent Connection Provider, and refers to an accredited company that can build electricity networks to the specification and quality required by Distribution Network Operators or an Independent Distribution Network Operators.

Successfully providing ICP and grid connections across all the distribution areas of the UK

Since Ofgem introduced the concept of Competition in Connections, Powersystems have been successfully providing grid connections across all of the distribution areas of the UK.

Powersystems have carried out a large number of grid connections for a varied clientele, ranging from Data Centres, Industrial Customers, Formula One Racing Teams, Health Trusts, Water Industry, Major Film Studio/Visitor Attraction and the Renewable Energy Sector.

Under our full scope of National Electricity Registration Scheme (NERS) accreditation we are able to undertake connection design work, cable installation, cable jointing, substation design and construction, switchgear and transformer installation and testing and commissioning services.

From application to energisation
Powersystems celebrate 24 years as the UK’s first Independent Connection Provider

Offering a ‘turnkey’ connection service
We have civil construction capability which enables us to offer clients a ‘turnkey’ connection service to include trenching works, directional drilling, substation building, construction and design from small 11kV substations up to 132kV primary substations.

We also offer a grid connection ENA application and feasibility study service through our engineering administration department, where Powersystems will deal with all aspects of your application and liaise with the DNO on your behalf.

Whether an industrial, commercial premises or generation scheme Powersystems are able to provide a competitive grid connection offer. Our team of engineers and support staff manage the entire connection process from initial application, design, construction and commissioning through to final energisation and adoption.

As an Independent Connection Provider (ICP) Powersystems have been assessed and accredited nationally by Lloyds register to carry out:

  • Project Management
  • Cable laying (LV, 11kV, 33kV, 66kV, 132kV)
  • Cable jointing (LV,11kV, 33kV, 66kV, 132kV)
  • Substation installation (11kV, 33kV, 66kV, 132kV)
  • All associated civil engineering works including excavation, cable laying and back-filling.

Project Management

Project Management

Project Management

Project Management

At Powersystems we have the staff, knowledge, skill set, tools and techniques to meet the requirements of your project.

There are five phases of project management which are the roadmap to successfully delivering your project whether it be a transformer change or a turnkey powerstation build.

Good project management reduces risk and will ensure you have a successful conclusion to your project every time.


One - Conception and Initiation

The work starts here. Powersystems can provide a quotation carefully tailored to your scope of supply and needs coupled with payment milestones, enabling you to effectively manage your project and finances with certainty.


Two - Design and planning the Project

Good design and planning is key to successful project management. Our forte is having a highly skilled team of engineers that can advise and help you plan your project ensuring there are no surprises once we execute the project.


Three - Project Execution

Each project has a dedicated Project Manager who will manage your project from conception to completion, ensuring that your project is delivered safely, within scope, on time, within budget and meeting your requirements.


Four - Project Performance and Monitoring

Powersystems will ensure that the project stays on track and ensuring that we take corrective action, as and when necessary, to ensure that it does. Keeping you informed with regular contact to ensure that you are kept up to date.


Five - Project Close

Formal handover of your project and debrief to review the project. This will help Powersystems to create a powerful ‘learning organisation’, accelerate future projects and lead to sharing innovative approaches to problems.




Maintenance / Fault Finding

In order to keep electrical infrastructure in good condition regular maintenance is recommended.

Here at Powersystems we can offer a maintenance regime to suit your high voltage electrical infrastructure. We also cover regular transformer maintenance which will be a requirement for your insurance company.

In the event of trips or faults, we have Senior Authorised Persons operating across the UK, working closely with teams of cables jointers and electricians who, using the companies in-depth knowledge of electrical testing systems will quickly identify and fix the fault.

Testing and Commissioning

Testing and Commissioning

Testing and Commissioning

Testing and Commissioning

The testing and commissioning of high voltage electrical equipment is a highly specialised activity with each and every installation being tested by a trained engineer to exacting standards.

Powersystems testing capability covers an extensive range of disciplines, including cable installations, transformers, switchgear, protection, earthing and underground fault location.

Powersystems testing capability covers an extensive range of disciplines.

Cable installations

  • 1kV and 5kV insulation tests
  • DC pressure tests up to 33kV
  • VLF cable testing


  • HV & LV winding insulation tests
  • Winding ratio checks
  • Bucholz testing
  • Oil sample and testing (electrical breakdown, acidity, water & PCB content, dissolved gas analysis)


  • AC pressure testing
  • Ductor testing
  • CT’s – Ratio & flick tests, mag curves
  • VT’s – Ratio & polarity checks
  • Functionality checks
  • Protection testing


  • Primary and secondary injection
  • Timing tests
  • Overcurrent and earth fault relays
  • Directional overcurrent and earth fault relays
  • Differential transformer protection
  • Translay and Solkor feeder unit protection
  • Restricted and standby earth fault relays
  • Generator loss of mains and G59 protection
  • Neutral voltage displacement
  • Transformer auto tapping relays
  • Inter tripping schemes.


  • Soil resistivity measurements
  • Final earth electrode resistance

Underground fault location

  • Digital pulse echo

Protection and Control Panels

Protection and Control Panels

Protection and Control Panels

Powersystems – building protection into the heart of your grid connection

The importance of protection to safeguard your plant

The selection of the correct protection and control scheme is fundamental to the operation of electrical systems under normal and fault conditions.

Our engineers understand this and will design the optimum system to interface between all the components of an individual site.

We have wide-ranging experience in designing protection schemes for demand and generation connections.

We also understand the intricacies of different types of generation and loads, having designed and installed numerous protection scheme for wind farms, solar parks, hydro schemes, synchronous generation, STATCOMs, rotating stabilisers, and industrial loads.

Using this knowledge, we are able to design, install, and test protection schemes right from concept through to final commissioning.

    The Protection Panel Grading Curve

    Protection design – the Powersystems approach 

    Firstly, we will select and specify appropriate protection relays, taking into account the reliability and performance requirements of the scheme; the interface between protection relays and the site SCADA infrastructure; the ability to test and maintain relays throughout the lifetime of the site; and considering the most economical and value-for-money solutions.

    Secondly, we will design the secondary control and protection wiring that interfaces with the relays. Our protection relays can be incorporated into the HV switchgear or installed in custom-built protection and control panels which we design and assemble in-house.

    Where we are providing custom protection panels, our CAD design engineers will prepare the AC and DC wiring schematics that are used for assembly of the panels.

    Or if we are incorporating relays into the HV switchgear, our engineers will thoroughly review the switchgear manufacturer’s schematics to ensure they incorporate proven principles to increase the reliability of the scheme such as:

    • Circuit breaker fail protection
    • Trip circuit supervision
    • Redundant main and backup DC supplies
    • Redundant main and backup protection relays
    • CT and VT supervision
    • Fail-safe (closed-when-healthy) alarm signalling
    • Appropriate isolation and testing points

    Our protection panel schematics are designed in accordance with ENA TS 50-19 Issue 2 – Standard numbering for small wiring, to ensure the wiring can be easily identified and tested.

    Next, we will carry out protection co-ordination studies to determine appropriate protection settings which will safeguard your plant from damage, whilst considering the need for appropriate discrimination to identify the location of faults, and the need to avoid spurious trips to ensure your plant is online and operational as much as possible. 

    Our co-ordination study will ensure fault clearance times meet the distribution and transmission standards, and that the plant remains operational within the voltage and frequency limits defined in Engineering Recommendation G99 and the Grid Code.

    Once the protection settings have been determined, our engineers will program the protection relays. We have experience applying protection settings and logic to numerous IEDs covering all the common brands such as ABB, GE Multlin, the Schneider / GE MiCOM range, Sepam, Siprotec, SEL, VIP 300/400, and the Siemens Reyrolle range.

    Within the IED logic we can interface with other relays on the site using communication protocols such as IEC 61850, DNP3, and Modbus.

    Finally, we will test and commission the scheme on site to prove correct operation. We will carry out the full suite of required commissioning including, secondary injection testing of relays; primary injection testing; functional testing; and proving of all signals back to your central SCADA system.


    Our experience in delivering quality protection schemes

    In summary, Powersystems engineers have extensive experience in specifying and installing the following protection schemes from 11 kV to 132 kV:

    • Over current and earth fault
    • Differential protection of cables, busbars, transformers, reactors, and generators
    • Restricted earth fault and standby earth fault schemes
    • G99 voltage and frequency protection
    • G100 reverse power protection
    • Auto-isolate and auto-reclose schemes
    • Energisation of transformers using point-on-wave controllers or pre-insertion resistors
    • Inter-tripping, blocking, and back-tripping
    • Neutral voltage displacement for unearthed or impedance-earthed systems
    • Check sync protection for synchronous generators
    • Auto-voltage control for transformer onload tap-changers
    • Automated switching of reactors, capacitors, and harmonic filters
    • Pole-mounted reclosers for overhead lines

    Pin It on Pinterest