High Voltage and Power Plants


The work of the High Voltage and Power Plants Department entails various fields connected with high voltage devices and electrical power facilities and their problems.

Areas of Work

High voltage devices and facilities

  • Overvoltage analyses (time-, switching- and atmosphere-related) and insulation coordination tasks,
  • computer simulations of electrical transients (EMTP, Sigma Slp) and numerical analyses,
  • the determination of the insulation level and the calculation of the reliability of overhead lines (atmospheric overvoltage),
  • the verification of suitability of the protection of facilities against direct lightning strikes (Strelec programme),
  • the calculation of overvoltage and the dimensioning of overvoltage protection (position, number, technical characteristics of conductors).
  • Issuing expert opinions on the suitability of devices and technical solutions,
  • numerical calculations of fields (electric, magnet, temperature) with computer-assisted numerical calculations (FEM – Comsol Multiphisics),
  • testing HV devices and measurements,
  • determining the technical characteristics of devices,
  • determining technical characteristics of cables and the calculations of heating for different application methods,
  • verifying the abilities of producers (production procedures, input material, QA, QC, testing, storing, documentation, transport),
  • cooperation with investors and project engineers during tenders,
  • supervising the tests and QA procedures during the takeovers of devices at producers,
  • monitoring procurement (procurement procedure, the verification of producers), the production (materials, interim and final testing, takeover) and installation (transport, functional tests, measurements after installation) of energy transformers.
  • Tests and measurements at the High Voltage Laboratory (measurements, HV tests, corona, temperature, partial discharges etc.),
  • controlling the insulation of HV devices in electric power facilities,
  • numerical processing and systematic storage of data for subsequent analysis,
  • situation diagnostics on the basis of measurements and operational data,
  • cooperation in the establishment of defects,
  • technical consulting in the establishment of the asset management system,
  • cooperation in the procedures of HV devices maintenance.

Power plants and other energy facilities

  • Consulting in the introduction of new technologies and solutions in the electric power system,
  • cooperation in the determination of technical specifications, the selection and ordering of HV devices,
  • help in planning, construction and restoration of electric power facilities,
  • resolving technical issues during construction,
  • ensuring the fulfilment of requirements of standards and legislation,
  • supervising the implementation of functional tests during the installation of devices,
  • revisions and expert assessments upon the conclusion of works,
  • the implementation of technological studies for new electrical power plants and for reconstruction of existing ones.
  • The implementation and review of technological studies for new electrical power plants and for reconstructions of existing ones,
  • work related to building new electrical power and industrial facilities (studies for preparatory work, expert and technical revisions),
  • monitoring, measuring and establishing operational characteristics of individual electrical and mechanical devices, device assemblies and entire electrical power or industrial facilities,
  • study work in resolving operational issues of electrical power facilities,
  • implementation of expert analyses of causes of defects on electrical and mechanical equipment in power plants, industrial facilities and the implementation of appropriate rehabilitation guidelines,
  • establishing the remaining life period of critical components of individual production sources,
  • expert cooperation in establishing system aspects of operation and the revitalisation of power plants,
  • expert and technical revisions, measurements and analyses of production facilities in accordance with valid regulations and recommendations.
  • Managing activities and security culture,
  • security report, procedures, technical specifications and other documents,
  • electrical systems,
  • regulation, protection and instrumentation,
  • accident analyses (probability and deterministic) including internal and external events,
  • protection against radiation,
  • impacts on the environment, including monitoring.


Machinery Laboratory (ML)

  • The production of advanced regulation and steering components in the field of power plants and other machine assemblies,
  • the implementation of functional measuring and supervision systems,
  • accurate measurements of electrical sizes, key for the assessment of operational abilities,
  • diagnostics and monitoring of operation,
  • testing of secondary management and regulation equipment in power plants.

High Voltage Laboratory (HVL)

The High Voltage Laboratory at the Milan Vidmar Electric Power Research Institute (HVL) is the leading testing institution in high voltage technology in Slovenia. As the testing laboratory it has the ISO-EN 17025 international accreditation for high voltage testing. The laboratory's activity is intended for research, development and education as well as testing for the needs of regular operation of important electrical power facilities.

With its capacities, the laboratory ensures testing according to the highest standards in various testing conditions, from normal conditions to tests in simulated rain conditions.

Laboratory's capacities:

  • Testing with high alternate frequency voltage 50 Hz from 0 to 700 kV
  • Testing with standard impulse atmospheric voltage 1.2/50 µs to 2400 kV
  • Testing with standard impulse switching voltage 250/2500 µs to 1500 kV
  • Testing with impulse current 8/20 µs, to 40 kA at 30 kV
  • Testing with high direct voltage to 600 kV
  • Testing with high alternate currents to 12 kA

Basic laboratory measurement methods:

  • Measuring alternate voltages to 500 kV (IEC-60060)
  • Measuring direct voltages to 1000 kV (IEC-60060)
  • Measuring atmospheric impulse voltages 1.2/50 µs to 1800 kV (IEC-60060)
  • Measuring switching impulse voltages 250/2500 µs to 1100 kV (IEC-60060)
  • Measuring impulse currents to 40 kA
  • Measuring electric currents to 10 kA
  • Measuring high ohm resistances (electric insulation)
  • Measuring low ohm resistances
  • Dynamic measuring of ohm resistances
  • Surface resistance of materials measurement (IEC-62631)
  • Electrostatic discharge of materials measurement (IEC-62631)
  • Volume resistance of materials measurement (IEC-62631)
  • Solid insulating materials measurement (IEC-60243)
  • Measuring dielectric losses factor (tg)
  • Determining dielectric constants of materials
  • Capacitance measurement
  • Inductance measurement
  • Impedance measurement
  • Recovery voltage measurement
  • Radio interference voltage measurement (IEC-61284)
  • Corona measurement (IEC-61284)
  • Partial discharge level measurement (IEC-60270)
  • Partial discharge level measurement according to the UHF method
  • Partial discharge level measurement according to the acoustic method
  • Contact measurement of temperature
  • IR measurement of temperature
  • Thermography

Highly qualified and specialised staff manage the modern measuring and testing equipment as well as carry out laboratory measurements, supported by scientific and research departments. This results in ensuring top quality analytical processing and appropriate interpretation of results of measurements and tests.

Two mobile units are operating within the scope of the High Voltage Laboratory and they are intended for routine tests of electrical machinery and devices at installation sites. Both units are functionally equipped and intended for diagnostic measurements of individual groups of electrical machinery and devices.

With regard to the laboratory's capacities and the use of individual sets of standard and non-standard measuring and testing methods, the laboratory enables a comprehensive scientific and technical consideration of the issues related to high voltage electrical technology. From the applicative aspect, the laboratory ensures quality diagnostic consideration of electrical devices in various fields for the needs of preventive maintenance, the assessments of envisaged life span and the establishment of operational reliability:

  • Power plants:
    • Diagnostic generator measurements
    • Diagnostic electric motor measurements
    • Operation and protection control
  • Overhead power lines (electricity transmission):
    • El. testing and dimensioning of insulation chains
    • El. testing of overhead power line conductors
    • Radio interference voltage measurement on overhead power lines
    • Corona measurement on overhead power lines
    • El. testing of HV cables
    • Operation and protection control
  • Switching transformer stations and distribution:
    • Diagnostic measurements of energy transformers
    • Diagnostic measurements of instrument transformers
    • Diagnostic measurements on breakers and isolating switches
    • Diagnostic measurements and tests with gas insulated switchgear (GIS)
    • Diagnostic measurements and tests of MV switchgear (switching blocks)
    • Diagnostic measurements on overvoltage conductors
    • Operation and protection control
    • Thermographic device testing
  • Industry:
    • Diagnostic measurements and tests at industrial energy facilities
    • Developmental measurements and tests of new products
    • El. measurements and tests on materials
    • Type testing
    • Approval tests
  • Working and security gear:
    • Testing of HV indicators
    • Testing of bus bars and assemblies
    • Testing of insulation tapes
    • Testing of el. gloves
  • Scientific and research areas:
    • Fundamental research for own needs
    • Applicative research in the field of own study research
    • Applicative research in cooperation with similar scientific and research institutions
    • Technical and research support to university study programmes



PHONE: +386 1 474 36 21

Head of Department

Ph. D., Simon Podkoritnik
Phone: +386 1 474 36 74
E-mail: simon.podkoritnik@eimv.si

Important publications of the department



years present in international markets


years active in research and development




accredited laboratories


expert departments


library literature units


implemented expert studies


active collaborations in domestic and foreign organisations