High frequency switching power supply (also known as switching rectifier SMR) works by high frequency MOSFET or IGBT. The switching frequency is generally controlled in the range of 50-100khz, achieving high efficiency and miniaturization.In recent years, the power capacity of the switching rectifier has been continuously expanded, and the capacity of the single machine has been expanded from 48V/ 12.5a and 48V/20A to 48V/200A and 48V/400A.
Ⅰ.The whole process of main circuit input and dc output from ac power grid, including:
Input filter: its function is to filter the clutter existing in the power grid, but also prevent the clutter generated by the machine to feed back to the public power grid.
Rectification and filtering: the grid ac power supply is directly rectified into a relatively smooth dc for the next level of transformation.
Inverter: the rectified dc into the high-frequency alternating current, which is the core of the high-frequency switching power supply, the higher the frequency, the volume, weight and output power ratio is smaller
output rectification and filtering: according to the load needs, to provide a stable and reliable dc power supply.
Ⅱ. On the one hand, the control circuit takes samples from the output end, compares with the set standard, and then controls the inverter to change its frequency or pulse width to achieve output stability.