Fiber optic current transformers

    The fiber optic current transformer measurement device is developed from fiber optic gyroscope technology. A well-known domestic company has a long-term research and development foundation for fiber optic gyroscope, and has a deep understanding of all aspects of the internal technology of fiber optic gyroscope, and has advantages in team and platform. It has many years of experience in optoelectronic instrumentation, has a high-level full-time team including the national "Thousand Talents Program" and the most advanced research and development platform in China, is one of the most important fiber optic gyroscopes and photoelectric sensing research and development and production bases in China, fiber optic gyroscope products, through the accurate measurement of the earth's magnetic field, to provide navigation of military aircraft, widely used in manned spacecraft, lunar exploration projects, launch vehicles, satellites and national defense weapons and other fields.
    Based on the Faraday magneto-optical effect and the Ampere loop theorem, the all-fiber current transformer (FOCT) accurately measures the Faraday optical rotation angle and measures the primary current through interferometer precision measurement and closed-loop control technology. FOCT can accurately measure not only power frequency AC current, but also DC, transient and higher harmonics. The two optical signals are transmitted in the same optical path, so the external factors of temperature and vibration have the same effect on the two signals, so the external conditions have no effect on the high-precision current measurement. The phase difference of the two optical signals has a strict correspondence with the measured current.
     The application area can cover 220V-1000kV optical fiber measurement device serialization and spectrum products, and the device can be integrated with high-voltage instruments and equipment such as high-voltage circuit breakers, gas-insulated switches, transformers, etc., which solves the problem of high-voltage insulation and air tightness, and saves more than 80% of installation space. Through the accurate measurement of current and voltage by optical fiber measurement device, the wide-frequency domain and non-intrusive measurement of electrical parameters such as impedance, frequency, amplitude, phase, power, power factor, three-phase unbalance, harmonic, distortion and so on are realized, and a complete optical fiber precision measurement system with electrical parameters in the wide frequency domain of electrical system has been formed.

Fiber optic voltage transformers

    Based on the Pockels effect, the optical voltage transformer realizes the non-contact optical accurate measurement of high-voltage primary voltage through dual-polarization optical path measurement, wide-frequency domain detection technology and high-voltage equipotential cavity, etc., and overcomes the problems of electromagnetic induction, poor sense of security, poor resonance and transient characteristics of capacitive voltage-dividing voltage transformer.
    Based on the Pockels photoelectric measurement principle, the all-optical voltage transformer realizes non-intrusive, wide-frequency domain and precision measurement of voltage, with an accuracy of 0.2/3P, and has the advantages of intrinsic safety, strong insulation ability, outstanding anti-fast transient overvoltage (VFTO) interference performance and reliability. In addition, the all-optical transformer greatly reduces the operation and maintenance cost, does not need regular maintenance, and can realize product status maintenance through state self-diagnosis, saving floor space. China has independently taken the lead in developing engineering products, solved the key technical problems of environmental adaptability and long-term reliability of passive electronic transformer temperature, vibration, etc., and has been applied in more than 10 engineering projects in the construction of intelligent substations in China, with more than 100 applications, and the products are running stably and the overall operation is good. Based on the new measurement principle, the optical voltage transformer has outstanding advantages in terms of integration, intelligence, safety and reliability, and has a broad application space in the future construction of intelligent substations.