Transmission Excellence ("TX") provides software, research and consultancy services in the field of electricity transmission. Our clients are offshore wind developers, and onshore & offshore transmission companies.

Our software products include:

• TXArray (which optimises the design of the “array” cables within an offshore wind farm),
• TXDynamic (which calculates dynamic ratings for wind farm export cables), and
• TXSims (which assists in the creation of advanced models of large grid systems)
• Our detailed model of the whole British grid (created with TXSims).
• Our energy system optimisation models.

For more information on our software, see the product sections below.

We have provided consultancy services to several major offshore wind developers, helping them with our knowledge of transmission technology and equipment costs. We also bring our understanding of commercial and regulatory aspects such as suitable rates of return for transmission assets, the UK’s OFTO regime, and national & international energy trading.

We have undertaken research for major industry players, looking at subjects such as the cause of export cable faults, how to accelerate offshore cable repairs, offshore substation design & maintenance, and the stability of inverter-dominated grids. We are currently undertaking research into applying machine learning techniques to grid stability studies.

For more information on our consultancy and research track record, and the skills that our staff can bring to clients, please see the “our experience” section below.

Since our foundation in 2015, TX has amassed an enormous amount of experience in consultancy and research – along with the experience we have gained through creating our software products, and the experience our staff brought to the company.

Typical consultancy clients are project developers and investors. For example, TX had a major multi-year engagement as part of a consortium that helped a large energy company to create an offshore wind division. This included being awarded very large areas of seabed through an auction process.

Recently we undertook a detailed analysis of offshore transmission costs for a wind farm developer, drawing on our detailed in-house cost estimation models. Using this, we subsequently provided the clients with a full set of rules so that each project could decide whether AC or HVDC export cables were superior, bearing in mind the latest trends in prices and lead times.

Frequently we are asked by project developers to advise on (onshore) grid connections. We have helped developers to understand the technical and regulatory regimes, we have assisted in discussions with TSOs, and we have even used our own TXSims software to investigate alternative onshore connection points.

We help investors to undertake due diligence into investments in offshore wind and transmission projects. For instance, we have provided strategic advice and due diligence to companies seeking to invest in offshore transmission assets under Britain’s Offshore Transmission Owner (“OFTO”) regulatory regime. In doing this, we can draw on the experience that our director gained from 7 years as Technical Director for an OFTO.

TX has undertaken more than 10 major pieces of research under contract to bodies such as the Offshore Wind Accelerator (a consortium of offshore wind developers), the Offshore Wind Programme Board, National Grid and NESO.

Research projects have included work on:

• Improving the capacity, reliability and repairability of submarine cables. This included chairing the group that investigated a spate of export cable failures caused by problems with their optical fibre cores.
• Reducing the capital cost of offshore substations by reducing their weight, and reducing their operational costs through advanced condition monitoring and condition-based maintenance.
• Simulation of future no-fossil-fuel scenarios where the British grid is dominated by renewable generation.
• Application of machine learning to improve grid simulation studies.

The image below is from a research project into improving submarine cable ratings. In order to verify a theoretical analysis, we subcontracted to a lab at Southampton University the construction of a full-size replica of an offshore substation’s J-tube (yellow). An actual submarine power cable (black with yellow stripe) was inserted and loaded to full current while thermocouples indicated the temperatures within the J-tube via the bundle of green wires.

TXArray

TXArray is an integrated software package that optimises the layout and sizing of array cables for offshore windfarms, considering costs, losses, resilience to failures, soil conditions and other infrastructure. It can prepare designs using any of the standard array architectures (linear strings, branched “trees” or loops), allowing the optimum architecture to be selected. We have extensively tested TXArray against designs created using alternative software and have found that it enables potentially huge savings: over €10m on large projects.

TXArray is currently being used to design the array cables for a very large UK offshore wind project.

The images below show examples of:
(a) The layout of array cables following optimisation. The red and yellow colours indicate different cable conductor areas. This particular wind farm uses a loop architecture. Soil data has been omitted.
(b) Soil data, with darker greys indicating more expensive burial and brown showing rock outcrops, which have been avoided by the optimiser

TXSims

TXSims allows the simulation of large grid systems at a very high level of detail (e.g. a 10 micro-second time step). TXSims works with the commercial electromagnetic transient software PSCAD, adding the automatic generation of input data from simple tables, the automatic running of multiple studies, and the post-processing of output data into a useful form (excel files and zoomable graphs viewable on any browser). TXSims also automatically runs loadflow studies, either as an output in itself, or to initialise a PSCAD study.

Using TXSims, we have built a model of the entire British grid (all 400kV and 275kV lines and substations), which has been verified against recorded system behaviour during disturbances. This has been used in work for National Grid in the UK, and in system studies undertaken for an offshore wind developer.

TXSims has been licenced to Britain’s National Energy System Operator (NESO). In addition, as part of a research project funded by NESO, we have developed a way to use AI technology to help simulations of complex software-controlled equipment (eg wind and solar generation, batteries and HVDC links) using PSCAD or other electromagnetic transient software. For more information, please see this paper.

TX has also built Energy System Optimisation models. These models calculate the optimum investment that should be made in order to maximise profits from renewable energy sources that vary from hour-to-hour in a complex weather-related way (e.g. wind and solar). For instance, at the request of a multi-national energy company, we built a model that optimally sized each component within a plant that would make green ammonia in a middle eastern country. This involved sizing various types of renewable generation, electrolysers, ammonia synthesis, multiple types of energy storage, and grid interconnection.

The images below show:
(a) power & voltages before, during and after a short circuit on the 400kV grid. The power feed into the grid from selected HVDC links and offshore wind farms is on the left, while voltages are on the right. In this case the grid returns to stable operation after the disturbance.
(b) a verification test, comparing observed voltage waveforms and waveforms predicted by TXSims following a single phase fault c. 100km away on the British 400kV grid

TXDynamic

TXDynamic is a software package that undertakes the thermal simulation of wind farm export cables. Given hourly forecast wind outputs, it calculates the cable’s temperature over decades, while considering the impact of output curtailment to avoid overheating. TXDynamic uses the latest solver technology to provide results in less than a minute without loss of accuracy.

Given a particular cable design, installation conditions and wind environment, TXDynamic is able to evaluate the net present value (NPV) of the wind farm income lost due to curtailment. This allows designers to instantly see if measures to improve cable rating are financially viable.

TXDynamic undertakes a load flow study to convert power to current. In this, the cable is represented using a long-line (multiple pi-equivalent) model. Active adjustment of voltage and reactive-power set points over the wind farm output range can be accommodated.

The software has been validated against industry standard Cigre TB-880, and against finite element model (FEM) studies. It has been used in the design of the export cables for a major UK project.

The image below is a graph showing the evolution of temperatures over several decades of simulated cable operation. The uppermost trace is the temperature of the conductor. The lower traces show the temperature of layers within soil around the cable, which is deeply buried at this point. This particular cable does not reach its maximum allowed operating temperature, and so power flows do not need to be constrained

Electromagnetic transient studies (EMT studies) are a sophisticated and compute-intensive type of grid stability study; they are required when wind and solar are the dominant sources of energy across a grid.

TX has completed a “proof of concept” study which has shown that a neural network running within an EMT study can learn to replicate the behaviour of software-controlled elements within a grid (e.g. wind farms) with the necessary speed and accuracy. We believe that this is a world first.

TX is investing to improve its compute facilities, adding a new machine with the latest NVIDIA processor. This allows us to run demanding machine learning tasks for a research client.

Power transmission is one of the most important, exciting and fastest growing fields in Britain’s energy industry.

Transmission Excellence’s emphasis on innovation makes us an exciting, fast-paced, entrepreneurial place to work where you will be employed in activities of real importance and will be able to look back with pride on work that has really made a difference to our industry – and to the country.

Even when we are not formally recruiting for a specified role, we are always interested in hearing from smart people with a technical background, good written communication skills and a desire to learn. Electrical Engineering qualifications are ideal, but highly motivated people with other technical backgrounds will also be considered. The work will be highly varied - but always interesting - including technical, regulatory, economic and human aspects, with none of the over-specialised silos that can be found in larger companies.

We are based in Kenilworth, in the heart of Britain. Not only does this put us at the centre of the transmission industry, it also means living and working in a beautiful part of the country, recently voted as one of the UK’s best places to live.

For more information please contact:

Sean Kelly

E info@transmissionexcel.com
T 07767 298 983

Office Address
28 High Street
Kenilworth CV8 1LY