In the paper a review on the potential advantages of optical current transformers points out that it is the technology trend
on the development of current transformer. But there are many more difficulties to be resolved, innovative ideas of
developing optical current transformers must be strengthened.
A high voltage current transformer project based on current thermal effect was introduced, which combined the current
thermal effects and the optical fiber thermometry technology. Fiber optic temperature sensor was the earlier and mature
product among fiber optic sensors in commercial, current thermal effects technology is more general applied, so the new
project has the advantages over other current transformer projects which are now meeting the difficulties hardly to
The relationship between the instantaneous value of measured current and the temperature rise was deduced, and the
mathematical model of the current transformer was established. By use of the mathematical model, in theory, the
instantaneous value of current can be tracked by the temperature output of sensor accurately, so that it can be used to
measure instantaneous value of current. The technical data and features required of the main devices and components can
be provided by use of the mathematical model for technical design of the project, simulation method and experiment
tests were used to prove the availability.
It is proved that most of the actual fluorescent decays contain non-exponential component. An instability factor is defined to express the goodness of the actual fluorescent decay using in thermometer. The principle of mathematical model established in a fluorescent decay thermometer is discussed. It is critical to establish an accurate mathematical model in temperature measurement based on fluorescent decay, a good mathematical model is the one which is consistent with physical reality. If short of such consistence The traditional single-exponential model would induce much error in higher level precision temperature measurement for it's only a theoretical assumption. A cutting and normalized method and an instability factor are defined to judge the influence of non-exponential deflection of the fluorescent decay curve. The principle of establishing a mathematical model is discussed. Its pointed out that the matching of the mathematical model and the data processing method are essentially important for the measurement, the deducing conclusions such as data processing precisions, experimental and simulation results are uncertainty as applying to actual fluorescent material. Prony method having the potential capability in dealing with multi-exponential decay model also is pointed out. The above conclusions are evaluated by computer simulations and experiments.