Optical instrument voltage transducers KRISMARS-VT


Download Proposal for investors

Power Industry policies of the Russian Federation have given a top priority for the development of Smart Grid concept. In particular, research and design of non-conventional instrument current and voltage transformers for networks 35 to 110 kV is the task of major importance.

Primary current and voltage sensors of optical type are acknowledged as having the best market potential.


Components: Optical voltage sensor and optoelectronic unit with a standard signal output or Merging Unit on its end (for Digital Substation applications).

Project status: investment offer.

Operating principle
Electro-optical effect of electro-gyration

For DSS applications
IEC 61850-9-2LE output

Testing tools
Reference equipment from Mars-Energo

Unique design feature:

Higher measurement accuracy (in comparison with the existing electro-gyration sensors) is achieved owing to Faraday effect compensation, namely:

Additional polarization rotation angle caused by the Faraday effect (induced by magnetic fields of large currents passing through the circuits) is compensated in the optical path designed so that “electro-gyration” polarization rotation angles of oppositely directed light beams are forced to be of the same sign, and “Faraday” polarization rotation angles become opposite in sign.


  • The crystal selected as an optical cell material provides high temperature stability of the electro-gyration constant and exhibits no piezoelectric effect, which gives the possibility to create a voltage sensor operating in wide temperature and frequency ranges
  • High measurement accuracy owing to Faraday effect compensation
  • The transducer can also be used for current measurements – the only thing to do is to replace the voltage (electro-gyration) optical cell with the current (Faraday) one


Parameter Value
Voltage ratings 10; 20; 35 kV to 110 kV AC
Accuracy class 0.2S; 0.5S
Frequency range 1 ... 10 000 Hz
Output signal:
  • Analogue
  • Digital

4; 100; 100v3 V
according to 61850-9-2LE
Fiber guide length between the optical sensor and optoelectronic unit Up to 200 m
Dimensions and weight
  • Optical sensor
  • Optoelectronic unit

130 х 290 mm, 5 kg, or less
134 х 215 х 450 mm, 3 kg, or less
Power supply (Optoelectronic unit) 220 V; 50 Hz