Main Factors Affecting Current Transformer Error

(1) The influence of primary current. When the primary current of the current transformer is very small, the error caused by it will increase; when the primary current is larger than the rated current for a long time, the error will also increase. Therefore, generally, the primary measurement current should be greater than 25% of the rated current of the transformer and less than 120 %.

(2) Influence of secondary load. When the secondary load of the current transformer increases, the error (, ratio difference and angle difference) also increases. Therefore, the secondary load should not exceed its rated value ( volt-ampere or ohm).

In addition, the frequency of the power supply and the remanence of the iron core also affect the transformer error.