The principle of zero magnetic flux realized by Electrical Current Transformer

1. The meaning of zero-flux Electrical Current Transformer

The error of the Electrical Current Transformer is generated by the alternating excitation current that provides the magnetic flux. If the magnetic flux is zero, then the transformer can be said to have no error, which can greatly improve the accuracy. This is the practical significance of the zero-flux Electrical Current Transformer. .

2. Principle of Electrical Current Transformer to achieve zero magnetic flux

The transformer must have a current output, even if the external short circuit (0 load), due to the internal resistance of the coil, there is bound to be a voltage drop. This voltage drop is provided by the electromotive force generated by the alternating magnetic flux. There are several ways to solve the problem of zero magnetic flux when there is current, one of which is to use another auxiliary transformer superimposed on the main transformer to provide back electromotive force to compensate for the voltage drop generated by I*R, so that The magnetic flux of the main transformer is not needed to provide electromotive force, and the purpose of zero magnetic flux is achieved. Another method is to use an external circuit to provide, but the external circuit to provide accurate in-phase electromotive force requires a little work. The former method is easier to implement and more accurate.

In theory, the zero-flux Electrical Current Transformer has no error, but because it is impossible to truly achieve zero-flux, coupled with the leakage inductance of distributed capacitance, the zero-flux Electrical Current Transformer still has certain errors. However, the accuracy of the transformer has been improved by at least an order of magnitude, and it does not require power supply. If the price can be reduced, it will have great prospects.