History and institutional framework of High Voltage and Electric Measurement Laboratory / National Technical University of Athens
The High Voltage and Electrical Measurement Laboratory of the National Technical University of Athens is considered one of the most historic laboratories of the University, officially operating since 1946. It is considered to be the successor of the «Electrical Laboratory», founded on 14.08.1911 (Law 3903, with its mains goals being the testing and consulting services about of electrical and gas installations, as well as the technical experimental training of students) and it is also considered to be the forerunner of all the laboratories of the School of Electrical and Computer Engineering (ECE).
Formally, it has been operating since 1946 (Government Gazette 375/1946) when the “Electrical Measurements and High Voltages” chair was established. In 1962 (Government Gazette 32/1962) it was instituted as “Laboratory of Electrical Measurements and High Voltages”. In 1973 (Government Gazette 208/1973) the name was changed in “High Voltage and Electrical Measurement Laboratory”.
Professor Ioannis F. Gonos is the director of the Laboratory.
The High Voltage and Electrical Measurement Laboratory supports undergraduate courses of the ECE School, postgraduate courses of the ECE Doctoral Education program, as well as courses of interdisciplinary programs of Postgraduate Studies. Meanwhile, the Laboratory participates very actively in the whole spectrum of electrical tests and measurements and electromagnetic compatibility (EMC) and immunity tests/measurements, extending its scope of expertise beyond High Voltage applications to the field of certification and compliance of electric equipment with national and international standards.
The Laboratory has long-term experience (since 1946) in the field of technical tests and measurements of devices and equipment. This service activity is provided continuously by the ELOT EN ISO 9001:2015 certified and by the ELOT EN ISO/IEC 17025:2017 accredited High Voltage Service Providing Laboratory Unit, which was established under the 22.03.1996 decision of the Senate of the National Technical University, in order to perform studies, tests, laboratory measurements and other related work.
The Scope of Accreditation of the High Voltage Service Providing Laboratory Unit includes various electrical tests and measurements (measurements of earth resistivity, ground resistance, step/touch voltage, dielectric strength under impulse voltage test on cables and transformers, measurement of low frequency magnetic and electric fields etc.) and electromagnetic compatibility/immunity tests and measurements. In fact, it is the only – to date – laboratory in Greece, whose Scope of Accreditation includes most of the harmonized standards applied for the documentation of conformity according to European Directive 2014/30/EU, which governs the electromagnetic compatibility of equipment.
○ Electrical Tests / Measurements
- RENEWABLE ENERGY PARKS – HIGH VOLTAGE SUBSTATIONS
– Earth resistivity measurement
– Step and touch voltage measurement
– Ground resistance measurement
- CABLES – TRANSFORMERS
– Dielectric strength under impulse voltage test on cables and transformers
- CRITICAL HOSPITAL AREAS
– Measurement of resistance to earth, surface and vertical resistance of resilient floor coverings and installed floors
- POWER TRANSMISSION LINES, SUBSTATIONS, HIGH VOLTAGE CENTERS
– Measurement of low frequency magnetic and electric fields
- LIGHTING EQUIPMENT
– Assessment of lighting equipment related to human exposure to electromagnetic Field
○ Electromagnetic Compatibility (EMC) and Immunity Tests and Measurements
The Laboratory is equipped with modern, calibrated equipment that is traceable to the National and International Standards and has highly specialized personnel.
- Measurement of conducted emissions in power ports of equipment in the frequency range from 9kHz up to 30MHz, which aims to certify that neighboring apparatus is not affected by the disturbances that are conducted through the interconnecting cables of the equipment
- Measurement of radiated emissions in the frequency range from 150kHz up to 18GHz, which aims to certify that neighboring apparatus is not affected by the disturbances emitted in terms of electromagnetic field from the enclosure of the equipment
- Measurement of discontinuous disturbances: transient conducted emissions generated by equipment with main functions that are carried out with motors and switching devices
- Measurement of disturbance power: measurement of continuous generated electromagnetic power disturbance in the frequency range from 30MHz up to 300MHz
- Measurement of the current harmonics emitted by the equipment to its power supply network, thus contributing to maintaining the power quality of the electricity network
- Measurement of voltage fluctuations and flicker which aims to certify that the equipment under test does not cause variations in its voltage supply
- Immunity to Electrostatic Discharge test aiming to certify that the equipment will not be disturbed by electrostatic discharges generated from other charged devices or operators
- Immunity to RF Electromagnetic Radiated Field test which aims to certify that the equipment will operate properly in an environment with radiated radio-disturbances
- Immunity to Bursts test which aims to certify that the performance of the equipment will not deteriorate in the presence of conducted disturbances caused by fast switching operations of contacts and loads
- Immunity to Surges test which aims to certify that the equipment will continue to perform properly when subjected to overvoltages or overcurrents caused e.g. by a lightning strike
- Immunity to Conducted Electromagnetic Field test which aims to certify that the performance of the equipment will not deteriorate in the presence of conducted RF disturbances
- Immunity to Power Frequency Magnetic Field test which aims to certify that the equipment will continue to perform properly in the presence of power frequency magnetic field
- Immunity to Voltage Dips and Short Interruptions test which aims to certify that the equipment will not be affected by variations or interruptions of its power supply
- Ιmmunity to conducted, common mode disturbances in the frequency range 0 Hz to 150 kHz which aims to certify that the equipment will continue to perform properly when subjected to low frequency conducted disturbances produced by the ship power network and telecom grid
- Immunity to transient phenomena test on power lines and immunity test (Standards ISO 7637-1, 7637-2, 7637-3, ISO 16750-1, 16750-2) to power supply interruption for on board vehicle equipment, which aims to certify that the equipment in the environment of a vehicle will not be affected by transient phenomena and specific types of variations of its power supply
The Laboratory is equipped with modern, calibrated equipment that is traceable to the National and International Standards. The Laboratory top class EMC test instrumentation provides an efficient way to perform functional examinations on all types of electronic equipment (such as information technology equipment, household appliances, luminaires, industrial, scientific and medical equipment, radio equipment, alarm systems, road traffic signal systems and many more) to determine their immunity and measure the unwanted electromagnetic disturbances. The highly specialized personnel of the High Voltage Laboratory, guarantees the reliability of the aforementioned measurements and tests.
○ Equipment Calibrations
The Laboratory is accredited to perform calibrations to:
- Electrostatic Discharge (ESD) generators
- Burst generators
- Surge generators
- Voltage dips, short interruptions and voltage variations equipment
- Power frequency magnetic field immunity test equipment
- Large Loop Antennas System (LLAS)