Overcurrent protection circuit for special power supply for magnetic suspension centrifugal blower

Abstract

The invention discloses an overcurrent protection method for a special power supply for a magnetic suspension centrifugal blower. An overcurrent signal passes through an overcurrent signal sampling and conditioning circuit and is output to the "-"-end of a comparator to be compared with a reference voltage; a CPLD chip comprises a dithering-elimination circuit, a latch circuit, a signal widening circuit and an overcurrent signal counting circuit; the dithering-elimination circuit delays 1.28 microseconds on the detected overcurrent signal and filters out an interference signal; the latch circuit latches the filtered overcurrent signal state in an SR latch; the signal widening circuit widens the overcurrent signal for 5.24ms to improve time of duration of detection of the overcurrent signal; and the overcurrent signal counting circuit determines whether to output an overcurrent protection action or not according to the number of times of generation of the overcurrent signal. By adoption of the overcurrent protection method, the technical problem that a fan transmission mechanism and the like are damaged easily caused by a fault that a rotor collides a protection bearing when the magnetic suspension blower suffers from transient overcurrent at the suspension moment of the magnetic bearing can be solved, wherein the fault is caused in cutting off of 300V output by the special power supply which is originally used for supplying 300V voltage for a protection bearing controller.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to an overcurrent protection circuit for a special power supply for a magnetic levitation centrifugal blower. Background technique [0002] With the rapid development of power electronics technology, high-power devices such as MOSFETs and IGBTs, which are key technologies, are widely used in various fields such as communications and electronics because of their excellent high-frequency switching characteristics. However, as a high-power composite device, they have a weak ability to withstand short-term overload. When the energy in the tube is accumulated due to overvoltage or overcurrent during operation, it is very easy to cause avalanche and damage the device. Therefore, in practical applications, overcurrent protection technology has always been the key to the reliable and stable operation of power devices. [0003] The power supply involved in the present invention is main...

AI Technical Summary

Problems solved by technology

[0009] An embodiment of the present invention provides an overcurrent protection circuit for a special power supply for a magnetic levitation centrifugal blower, which can solve the problem of cutting off the special power supply that originally supplied the 300V voltage to the protective bearing controller when the magnetic levitation blower temporarily overcurrents when the magnetic bearing is suspended. The 300V output causes the rotor to hit the protection bearing failure, which leads to vulnerable technical problems such as the fan transmission mechanism

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