An uninterruptible power supply overcurrent protection circuit

Abstract

The invention provides an uninterruptible power supply over-current protection circuit which is strong in protection function and more reliable in performance. The uninterruptible power supply over-current protection circuit comprises a main circuit, a control circuit and a drive circuit, wherein the main circuit comprises IGBT tubes V1-V4, a diode V5, a diode V6, a current transformer T1, a current transformer T2, resistors R1-R10, capacitors C1-C5, an inductor L1 and an inductor L2, the control circuit comprises a CPLD chip N3, a chip N1, a chip N2, a chip N4, a chip N5, a chip N7, a chip N8, resistors R11-R27, resistors R44-R47, capacitors C6-C14, a crystal oscillator H1 and a peripheral device, and the drive circuit comprises an IGBT drive chip N6, a peripheral circuit device, an IGBT drive chip 1N6 and a peripheral circuit device. The uninterruptible power supply over-current protection circuit is high in circuit collection protection function, high in peak current bearing capacity and high in efficiency, a power supply can uninterruptedly work in an environment with multiple rectification capacitive loads, data are prevented from being lost, and maintenance cost is reduced.

Description

technical field [0001] The invention relates to the technical field of a power supply, in particular to an overcurrent protection circuit of an uninterruptible power supply. Background technique [0002] The load of an uninterruptible power supply (referred to as a power supply) is generally a computer load (referred to as a load). After the power supply is turned on, the load is plugged in. If the load has a large capacitance, the current at the moment of starting is very large, especially when the load is connected. When the output voltage of the power supply peaks, the phenomenon of power failure and restart of the power supply often occurs, and even the power supply may be damaged. Therefore, power supply manufacturers choose high-current main circuit switching devices to make the power supply withstand as large a peak current as possible, but there will still be power outages. [0003] The overcurrent protection of the power supply is mainly the protection of the switc...

AI Technical Summary

Problems solved by technology

This kind of protective measure has poor anti-interference ability. Once a fault is detected, the device will be shut down, which is prone to malfunction. Therefore, in order to increase the anti-interference ability of the protection circuit, a fixed delay is often added between getting the fault signal and starting the protection circuit. , however, the fault current will rise sharply within a fixed time delay, which will greatly increase the power loss of the device during the fault. At the same time, the increase of the fault current will also increase the di / dt (current change rate) when the device is turned off by fault, The parameter design between them is difficult to compromise, so the traditional protection circuit, when a fault occurs, the protection circuit is often activated, but the device may still be damaged

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