Electrical Current Transformer4 large internal parameters affect the error

1. The influence of the internal resistance of the secondary coil R2 and the leakage reactance X2 on the error: when R2 increases, the ratio difference and the angle difference increase; when X2 increases, the ratio difference increases, but the angle difference decreases, so the error should be improved. Try to reduce R2 and appropriate X2 values. Since the internal resistance of the secondary coil R2 and leakage reactance X2 are small compared with the secondary loads Rfh and Xfh, changing R2 and X2 has little effect on the error, and only the small-capacity Electrical Current Transformer has a significant effect.

2. The influence of core cross section on error: the increase of core cross section reduces the magnetic flux density of the core, and the excitation current decreases, thereby improving the ratio difference and angular difference. Without compensation, the magnetic flux density of the core of the Electrical Current Transformer is already very small under the rated conditions, so reducing the magnetic flux density also reduces the permeability coefficient relatively, so that the excitation current is not reduced 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 ampere-turns. 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, and at the same time cause a decrease in the dynamic stability multiple and an increase in the saturation multiple.

4. Reduce core loss and increase magnetic permeability. Under the condition that the magnetic flux density of the iron core remains the same, reducing the excitation ampere-turn and loss ampere-turn of the iron core will also improve the ratio and angle difference. Therefore, the use of high-quality magnetic materials and the adoption of appropriate annealing processes can achieve improved magnetic permeability and The purpose of reducing losses. The magnetic properties of the iron core also affect the saturation multiple, and the saturation multiple is better when the iron core has poor magnetic properties.