High Voltage Technology

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Picture of Sven Schumann

Name

Sven Schumann

Head of Department Energy System Technologies

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+49 241 80 93035

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High Voltage Technology

The IFHT has direct access to a wide range of test equipment and is therefore able to offer a variety of different research and engineering services. The main scope consists of testing services for insulating materials in different electrical equipment like circuit breakers, power cables or insulators. For example standardized tests for the determination of surface and volume resistivity, electrical breakdown strength or for dielectric parameters (permittivity, loss factor) are part of the portfolio. Also investigations on material characteristics and the ageing of insulation materials at different environmental influences (temperature, humidity…) are possible. Furthermore, non-electrical investigations (e.g. non-destructive material tests by ultras sonic diagnosis, confocal microscopy, contact angle measurement...) can be performed. The following test setups and laboratories are available for research and engineering.

Test bench 1: High- and Medium voltage generation

High- and Medium voltage generation Copyright: Martin Braun

The IFHT features high voltage laboratories for examinations that have a high voltage demand, like breakdown tests. Alternating, direct and impulse voltages (1,2s/50s, 250s/2500s) can be generated.

Technical data:

  • Alternating voltage: 400 kV, 200 kVA
  • Direct voltage: 270 kV, 3,5 kVA
  • Impulse voltage: max. 1 MV, 30 kJ

Test bench 2: Climatic- and environmental conditions

Climatic- and environmental conditions Copyright: Martin Braun

The IFHT offers in total three climate chambers (including an accessible one), which are mainly used for investigations of insulation materials under climatic loads. For example, the resistivity of materials under differing climatic conditions can be determined. Furthermore, the climate chambers are used for specimen conditioning under defined environment conditions.

Technical data:

  • Temperature: -40C to 220 C
  • Relative Humidity: 10% to 96%
  • Area of dew-point: 10C to 90C

Test bench 3: Insulation materials

Insulation materials Copyright: Martin Braun

Several test benches and measurement systems for testing and characterization of insulation materials and insulation systems can be used at IFHT. The manufacturing of (filled) liquid silicone rubber (LSR) and epoxy resin samples is possible in our material processing laboratory.

Technical data:

  • AC up to 100 kV
  • DC up to 100 KV

Test bench 4: Ultrasonic diagnostic

Ultrasonic diagnostic Copyright: Martin Braun

Multiple ultrasonic test benches are available at the IFHT for non-destructive testing of electrotechnical components like power cables or joints. In addition to detection and localization of defects (e.g. inclusions or delaminations), the acoustical properties of materials can be determined.

Technical data:

  • Spatial resolution up to 50 m
  • Testing frequency up to 15 MHz
  • Typical samples: medium and high voltage power cables, cable joints, silicone composite insulators, etc.

Test bench 4: Ultrasonic diagnostic

Ultrasonic diagnostic Copyright: Martin Braun

Multiple ultrasonic test benches are available at the IFHT for non-destructive testing of electrotechnical components like power cables or joints. In addition to detection and localization of defects (e.g. inclusions or delaminations), the acoustical properties of materials can be determined.

Technical data:

  • Spatial resolution up to 50 m
  • Testing frequency up to 15 MHz
  • Typical samples: medium and high voltage power cables, cable joints, silicone composite insulators, etc.

Test bench 5: Conductor technologies

Conductor technologies Copyright: Martin Braun

The laboratory for conductor technologies provides comprehensive possibilities to perform thermal investigations on overhead conductors, clamps, fittings or similar components under defined weather conditions. Electrical and mechanical parameters like current and tensile stress can be adjusted as well as ambient influencing variables like wind speed, global radiation and ambient temperature. A modular measurement and control system allows logging different temperature channels and the specification of defined exposure profiles.

Technical data:

  • current: up to 3 kA
  • tensile stress: up to 50 kN
  • ambient temperature: up to 40 C
  • wind speed:0,4 m/s to 12 m/s
  • global radiation: 500 W/m to 950 W/m

Test bench 6: SF6-Labor

SF6-Labor Copyright: Martin Braun

For simultaneous preparation and execution of experimental circuit breaker tests, two synthetic Weil-Dobke test circuits are available at IFHT with three separate test places. By means of transient recorders with up to 40 measurement channels, it is possible to record a wide range of parameters (e.g. current, voltage, pressure, etc.). A high-speed camera is available for optical investigations. A modern gas-handling system ensures a safe and environmentally friendly execution of tests in different gases.

Technical specifications:

  • Short circuit currents: up to 60 kApeak
  • Frequency: 50 Hz
  • Recovery voltage: up to 140 kV

Test bench 7: Cryogenic applications

Cryogenic applications Copyright: Martin Braun

For investigations on insulation materials for applications in high temperature superconductivity, a cryostat with a high voltage bushing is available at IFHT. Herewith, electrical investigations in liquid nitrogen (LN2) can be conducted.

Technical data:

  • AC voltages up to 125 kV
  • Lightning impulse up to 250 kV
  • Temperature range: 65-77 K
  • Filling capacity LN2: ca. 60 Litres

All tests can also be performed according to different standards or test procedures as well as according to specific customer requirements.