Electrical Current Transformer4 major internal parameters affect the error

1. The influence of the internal resistance R2 of the secondary coil and the leakage reactance X2 on the error: when R2 increases, both the ratio difference and the angular difference increase; when X2 increases, the ratio difference increases, but the angular difference is reduced. Therefore, the error should be improved. Minimize R2 and appropriate X2 values. Since the internal resistance R2 and leakage reactance X2 of the secondary coil are very small compared with the secondary loads Rfh and Xfh, changing R2 and X2 has little effect on the error, only the small-capacity Electrical Current Transformer has a significant effect.

2. The influence of the iron core section on the error: the increase of the iron core section reduces the magnetic flux density of the iron core and the excitation current, thereby improving the ratio difference and angle difference. The magnetic flux density of the iron core of the Electrical Current Transformer without compensation is already very small under rated conditions, so reducing the magnetic flux density also reduces the magnetic permeability relatively, so that the excitation current does not decrease much, and the smaller the magnetic flux density, the better the effect. Difference.

3. The influence of the number of coil turns on the error: Increasing the number of coil turns is to increase the ampere-turn. Increasing the number of turns can reduce the magnetic flux density, and the effect of improving the error is much more significant than increasing the core section. However, the increase in the number of coil turns will cause an increase in the amount of copper, a decrease in the dynamic stability factor and an increase in the saturation factor.

4. Reduce core loss and improve magnetic permeability. Under the condition that the magnetic flux density of the iron core remains unchanged, reducing the excitation ampere-turn and loss ampere-turn of the iron core will also improve the ratio difference and angle difference. Therefore, the use of high-quality magnetic materials and appropriate annealing processes can improve the permeability and The purpose of reducing loss. The advantages and disadvantages of the iron core's magnetic properties also affect the saturation multiple. When the iron core's magnetic properties are poor, the saturation multiple is relatively correct.