Two Factors To Be Considered In Selecting Micro Current Transformer

- Sep 07, 2018-

Micro Current transformers work according to the principle of electromagnetic induction, the so-called current transformer, usually composed of closed iron core and winding.

Current transformer and transformer similar is also based on the principle of electromagnetic induction, transformer transformation is the voltage, the difference is that the micro-current transformer transformation is the current. Usually in the application to include a different situation, generally we are the micro-current transformer connected to the measured current winding (the number of turns is N1), known as a winding (or the original edge winding, primary winding); the winding of the measuring instrument (the number of turns is N2) is called two times winding (or side winding, secondary winding).

More common for precision measurement transformers, according to different needs of different models of precision current transformers, but in order to improve the accuracy of the measurement, so in the current transformer selection process should be considered in the following two aspects: The first is to take into account the effects of a single current.

This is because in the micro-current transformer in the work, its primary current is relatively small, then the resulting error will be relatively large, and when the primary current is longer than the rated current operation, will also cause the error increase, therefore, the general primary test current should be greater than 25% of the transformer rated current, less than 120%. In this case, we need to combine the rated range of the product to select the primary side current of the transformer during the selection of the micro current transformer. The second is to take into account the impact of two loads. When the load of the current transformer increases two times, the error (ratio difference and angular difference) also increases.

Therefore, two loads should not be allowed to exceed their rating (voltammetry or ohm) in use. In fact, the two load capacity of the micro current transformer is mainly dependent on the rated capacity of the current transformer, the rated capacity of the current transformer is the rated two current I2e through the rated load Z2e consumption of the apparent power, that is, s2e=i2e²xz2e. In the production process of transformer, the core and cross-sectional area of the transformer can affect the rated capacity of the current transformer.