When the transformer voltage is a rated voltage, the secondary voltage in the end is how to change with the load, what is the basis for the theory of the way you ask you about the inrush
2 excitation current characteristics
When closing the circuit breaker to charge the transformer, sometimes you can see the transformer ammeter pointer put great, and then quickly return to the normal no-load current value, the impact current is usually called the inrush current, features are as follows:
1) The inrush current contains high-order harmonic components (mainly secondary and tertiary harmonics), so the variation of the inrush current is a steep wave.
2) The attenuation constant of the inrush current is related to the saturation of the core. The deeper the saturation, the smaller the reactance and the faster the attenuation. Therefore, at the beginning of the moment decay quickly, then gradually slow down, after 0.5 ~ 1s after its value does not exceed (0.25 ~ 0.5) In.
3) Under normal circumstances, the greater the capacity of the transformer, the longer the duration of attenuation, but the general trend is the inrush current decay rate is often slower than the short-circuit current attenuation.
4) The value of the inrush current is very large, the maximum rated current of 8 to 10 times. When setting up a circuit breaker to control a transformer, the quick break can be set according to the transformer excitation current.
When the primary voltage of the transformer is rated voltage, the secondary voltage does not decrease with the load current, but this is only the case where its rated power is not exceeded, and the magnetization will increase when the secondary current increases Paul its current output, a power beyond its maximum, the secondary current increases the voltage will drop until the fever burned. Inrush Current 1 Overview
Transformer is based on the principle of electromagnetic induction made of a static electrical appliances, for the low voltage into a high voltage or high voltage into a low voltage, AC transmission and distribution system is an important electrical equipment. When the transformer is closed, it may produce a large current, this paper mainly discusses the current generation and influence.
