Self-adaptive soft start system and method for high voltage switch power supply

Abstract

The invention relates to a self-adaptive soft start system and method for a high voltage switch power supply, belonging to the technical field of starting of a high voltage switch power supply. 2kV above direct current high voltage switch power supplies can be boosted to a nominal voltage according to a set boosting slope. The system mainly comprises a power supply, a rectifying and wave-filtering circuit, an inverter circuit, a pulse transformer, a high voltage rectifying and voltage / current sampling circuit, a voltage comparator, a single-pole double-throw switch A, a single-pole double-throw switch B, a ramp voltage generating circuit, a ramp current generating circuit, an error amplifier and a soft start control circuit. The method comprises the following steps: the voltage / current sampling circuit samples; the voltage comparator outputs a corresponding voltage value; the two single-pole double-throw switches are switched; the error amplifier calculates an error and outputs a control voltage to the soft start control circuit; the soft start control circuit then controls the inverter circuit, so that the high voltage switch power supply is boosted to the nominal voltage; therefore, a surge current or a overshoot voltage generated by a capacitive load and a inductive load are effectively reduced, and the reliability of the switch power supply is improved.

Description

technical field [0001] The present invention relates to an adaptive soft-start system and method for a high-voltage switching power supply, in particular to a system and method capable of realizing a high-voltage switching power supply above 2kV can rise to The technology of rated output voltage belongs to the technical field of soft start of high-voltage switching power supply. Background technique [0002] High-voltage switching power supply is widely used because of its wide input voltage range, high conversion efficiency, small output ripple and stable operation. Its load form can be capacitive load or inductive load. Ordinary soft-start high-voltage switching power supply has a rising slope or boosting slope much larger than the set slope when it is under capacitive or inductive loads, which can easily lead to excessive output surge current or voltage overshoot of the switching power supply. Damage to switching power supply and load. Adaptive soft-start technology can...

AI Technical Summary

Problems solved by technology

When the external switching rectifier is turned on, the current on the power inductor is sampled, and the stepwise change of the duty cycle is controlled by limiting the peak current change from small to large in stages, so that the output voltage rises slowly in stages, which can effectively avoid the start-up process The surge current in the medium, but there is a problem that the ability to suppress the overshoot voltage generated by the inductive load is not good

[0009] The above documents and patents either have a good suppression effect on the inrush current, or have a good suppression effect on the overshoot voltage, and the two cannot be balanced

Due to the complexity and uncertainty of the switching power supply load, the above documents and patents have certain limitations, and the boost or current ramp cannot be set according to the needs.

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