Circuit with wide input voltage range, high-frequency switching power supply and control method

Abstract

The invention relates to a circuit with a wide input voltage range, a high-frequency switching power supply and a control method. The circuit comprises an alternating current input and rectification circuit, a PFC (Power Factor Correction) inductance circuit, a soft-start circuit, a booster circuit, a follow current circuit and a control circuit, wherein the alternating current input and rectification circuit is used for connecting a three-phase alternating current input voltage, and rectifying three-phase alternating current input voltage into a pulsating direct current voltage; the PFC inductance circuit is connected with the alternating current input and rectification circuit, and used for regulating the input power factor of the high-frequency switching power supply; the soft-start circuit is connected with the PFC inductance circuit; the boost circuit is connected with the soft-start circuit, and used for generating an output setting voltage; the follow current circuit is connected with the soft-start circuit; and the control circuit is connected with the PFC inductance circuit, the soft-start circuit and the booster circuit respectively. Through adoption of the circuit, the problem concerned with how to realize a high-frequency switching power supply with a wide input voltage range is solved effectively, and the wide range input characteristic of the high frequency switching power supply is realized. The circuit is simple in structure, clear in control logic, and safe and reliable.

Description

technical field [0001] The invention relates to the field of electric power, and more specifically relates to a circuit with a wide input voltage range, a high-frequency switching power supply, and a control method. Background technique [0002] The DC operating power system is an important guarantee for the continuous power supply of the power system. The high-frequency switching power supply for the power operating power supply is the core device of the DC operating power system. Its input is taken from the three-phase or single-phase power of the grid. Under normal circumstances, the voltage of the power grid will be greatly reduced, and in severe cases it will drop to about 40% of the normal voltage, which will make the high-frequency switching power supply module for electric operation power supply unable to work normally. [0003] At present, the widest input voltage range of the most commonly used high-frequency switching power supply for power operating power supplie...

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Problems solved by technology

[0002] The DC operating power system is an important guarantee for the continuous power supply of the power system. The high-frequency switching power supply for the power operating power supply is the core device of the DC operating power system. Its input is taken from the three-phase or single-phase power of the grid. Under normal circumstances, the voltage of the power grid will be greatly reduced, and in severe cases it will drop to about 40% of the normal voltage, which will make the high-frequency switching power supply module for electric operation power supply unable to work normally.

[0003] At present, the widest input voltage range of the most commonly used high-frequency switching power supply for power operating power supplies on the market is about 0.85 to 1.25 times the rated voltage. The range of input voltage is mainly affected by the gain adjustment range of the DC / DC conversion circuit. The high-frequency switching power supply DC / DC conversion circuit for power operation power supply mostly adopts phase-shifted full-bridge or LLC topology, but the characteristics of these two topologies determine that when the input voltage range is very wide, the gain adjustment cannot meet the design requirements

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