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Contact details

e-mail  taylor@kth.se

office  +46 (0)8 790 6222
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Postal address
 Nathaniel Taylor
 Teknikringen 31
 100 44 Stockholm

Visiting address
 Teknikringen 31
 114 28 Stockholm
   floor 4, room 1433

  KTH main campus
  Teknikringen 31   Alfvénlaboratoriet (picture)
  enter vestibule, door to right, up 1 floor,
  door to left, phone for entry if necessary


  { 59.3497 N, 18.0724 E }


KTH profile-page

Own webpages

I work at the department of Electromagnetic Engineering EME, within the school of Electrical Engineering and Computer Science EECS, at the Royal Institute of Technology KTH in Stockholm.

The following short points are intended to give a simple overview of my work, to a reader not deeply involved in the subject. Please see the links to get more detail.


For an indication of the main current projects I'm working on, see the list of PhD projects in my group.

See also the list of Publications.

The subjects I work with are described further below.

High-Voltage Engineering

High-voltage measurements, materials and insulation diagnostics were my main subjects from 2004 onwards. I am principal or co-superviser for several PhD students working in diverse topics within this area.

Diagnostic methods for insulation in large rotating machines – such as hydro-power generators – has been a recurring theme. These generators are becoming more critical in the power system, for balancing changes in wind-power and solar-power production. Projects have been supported by several companies in different parts of this industry. We also work with improving diagnostics of large motors, which have quite similar insulation to the generators. Even within the subject of low-voltage motors, we have a project about which methods of widespread monitoring would be profitable for improving operational reliability of industrial facilities.

Transformers are other critical components in the power system, as large ones can take a long time to repair or replace besides having high cost. They tend to be loaded more heavily than in the times before changes of electricity regulation and increased renewables. We have run several projects about transformer-type insulation with PhD students, postdocs and direct industry involvement. For example, causes and effects of partial-discharges in transformers, diagnostic methods that determine dielectric response based on excitation by natural transients, and methods for detecting moisture levels.

Earlier work in the group included diagnostics of the condition of polymeric cable insulation. I have little connection to this application, but have been involved in material characterisation for nanofilled variants of plain 'PE' or 'XLPE' cable insulation.

Power System Protection and Electrical Safety

A growing part of my work since 2014 has been with protection systems. This subject considers the power-system components, their typical faults, and measurements and principles that permit rapid detection of the faults.

Protection in medium- and high-voltage systems is often considered under the traditional name of protective relaying, but the important topics for work are developments beyond the well-established traditional methods. Changes are needed in order to provide reliable system operation in the system conditions expected in the future. Those conditions include, in the case of Sweden, a reduction of nuclear generation, larger international exchanges of power, increased wind and solar generation, and more use of electricity for heat pumps and electric-vehicle charging. Protection will need to operate more sensitively and quickly, in spite of its input signals being generally less clear on account of widely-varying generation sources and weaker short-circuit currents. Thus, the foreseen changes in the system tend to put higher demands on performance while making it more difficult to acheive these. One helpful ingredient that gives the potential to do this is the improved performance and price of sensing, communication and data processing. I currently have PhD projects in protection topics related to distribution and transmission systems.

My interest in protection extends to low-voltage systems, in which protection is not traditionally associated with 'relaying'. This includes analysis of what types of protection device and system design are most suitable in order to preserve or improve safety levels with future changes in requirements and possibilities. For example, how should satisfactory safety be assured even when local systems might sometimes operate as 'islanded microgrids' where the supply can come from modern types of sources such as batteries and solar cells? Even within the traditional situations there are important issues about the cost/benefit of different types of LV protective devices, and about the best options for protective earthing/bonding in different situations.


I also work with other subjects, a little outside the above headings but usually within electric power engineering. These are sometimes connected to my own work or to MSc theses that I supervise. Some examples are: ways to charge for using a power distribution network or a rural microgrid; effects of weak sources on power quality during network faults; and reasons for changes in load behaviour over the past years. It is rare to get funding for work in these subjects, or indeed for matters of electrical safety.


KTH's automatic Profile page for me gives some further details of course-involvement.


In the past eight years I have been responsible for courses in Electric Circuit Analysis for several programs: Energy and Environment (EI1120), Electrical Engineering (EI1110), and Information Technology and Microelectronics (EI1102). These have been adjusted to the focus that the programs have, but all contain at least basic dc, transient and ac analysis of linear circuits. Currently I am teaching just the Energy and Environment course.

Besides this I have contact with Electrical Engineering students in their early years at KTH through project tasks and mentoring.


Within the international MSc program in Power Engineering I am involved in courses and thesis supervision. I am responsible for a course in Power System Protection (EI2439) which I started in 2014 and run each autumn. I develop and run project tasks in the Electrotechnical Modelling course (EI2433) for students in the Electrophysics and Power programs. In the courses on High Voltage Engineering and Electrotechnical Design I previously have designed and run tasks and laboratory exercises. I usually have several MSc-thesis students active at a time, with projects on wide-ranging topics not necessarily coupled with our other projects.

Other work

Current administrative tasks include work as deputy-director of the funding organisation SweGRIDS.


My undergraduate degree was MEng (Electrical and Electronic Engineering) at Imperial College, London, in 2001. The final year was an exchange here at KTH, reading courses mainly in power-systems and high-voltage and doing a final year project. This was followed by postgraduate studies in power systems at Imperial College, studying coordinated voltage control in power systems.

I took the licentiate and PhD degrees in high-voltage engineering here at KTH, investigating dielectric spectroscopy at low and variable frequency, and their combination with partial-discharge measurements, for condition assessment of stator insulation in large rotating machines. More on that can be found here: DS and PD project.

My habilitation (docent) is also from KTH, in the broad area of "electric power".

Page started: 2004-05-01
Last change: 2011-08-22 -->