Transient Effect of Magnetic Saturation on Transformer

Magnetic saturation transient effect of the transformer Note that magnetic flux should be checked for saturation near minimum input voltage and maximum pulse width. As the input voltage is high, the pulse width will be narrowed, so the core is far from saturated. In a transient load, when the input voltage is high and the load current is small, if the load current suddenly increases, the control circuit immediately increases the pulse width to provide the supplemental power. In this way, the input voltage and pulse width are simultaneously maximized, even if for a short period of time, the single phase step down transformer will appear saturated, and cause out of control and failure. Here are some measures to avoid runaway. (1) transformer in accordance with high input, voltage, wide pulse design, the core work in low flux density and winding more primary winding. The disadvantage of this method is to reduce the efficiency of the transformer, increasing the size of the Amorphous Core Transformers weight. (2) the control circuit should be in the high sensitivity to determine the state of work, when the high input voltage appears to be able to quickly limit the pulse width, it is still safe value. (3) in the control circuit to improve performance, so that the switch in the current work cycle to quickly respond to control. UC1846 / UC1847 current mode control chip, can automatically achieve this limit action.