Due to the structure and material properties of the current transformer core, the current transformer has an exciting current Í0, which causes errors.
(1) The influence of primary current. EBW shunt resistor
When the primary current of the current transformer is very small, the error caused will increase; when the primary current is greater than the rated current for a long time, it will also cause the error to increase. Therefore, the general measured current should be greater than 25% of the transformer rated current and less than 120 %.
2) The influence of the secondary load. When the secondary load of the current transformer increases, the error (, the ratio difference and the angle difference) also increase. Therefore, the secondary load should not exceed its rated value (volts) during use. Ampere number or ohm number).
In addition, the frequency of the power supply and the remanence of the iron core also affect the error of the transformer.