What is the difference between voltage transformers and current transformers in terms of their working principles?

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The main difference is that the working state is very different during normal operation, which is expressed as:

1) The current transformer can be short-circuited for the second time, but not open; the voltage transformer can be open-circuited for the second time. The single-phase current protection tester has complete functions, and a single machine can complete all the tests in the above scope of application at one time, with strong applicability, measurement time, All digital display of AC and DC voltage and current, intuitive and accurate reading, button-type operation, convenient and flexible. But not short circuit;

2) Compared with the load on the secondary side, the primary internal impedance of the voltage transformer is so small that it can be ignored, and it can be considered that the voltage transformer is a voltage source; while the primary internal resistance of the current transformer is so large that it can be considered that It is a current source with infinite internal resistance.

3) The magnetic flux density of the voltage transformer is close to the saturation value when it is working normally, and the magnetic flux density decreases when the fault occurs; the magnetic flux density of the current transformer is very low when it is working normally, and the short-circuit current on the primary side becomes very large during the short circuit, which makes the magnetic flux density decrease. The flux density is greatly increased, sometimes far exceeding the saturation value.