Poweroff detection method of alternating current power supply and poweroff protection method of direct current inverter compressor

Abstract

The invention discloses a poweroff detection method of an alternating current power supply and a poweroff protection method of a direct current inverter compressor. A wave form of alternating voltage of the alternating current power supply is detected, and when an absolute value of an amplitude value of the alternating voltage is less than a protection threshold Vp and the duration exceeds the set hold time T, the alternating current power supply is determined to be powered off, wherein when the hold time T is normally greater than the alternating voltage, the experienced dead time from -Vp to +Vp or from +Vp to -Vp before and after zero is t0. The poweroff detection method of the alternating current power supply can be used for detecting the alternating current power supply in real time, detecting the instantaneous poweroff condition of the power supply within short time, quickly reacting to the control of a controlled object, and implementing quick protection. When the method is used for poweroff protection of the direct current inverter compressor, a power supply inverter and the direct current inverter compressor can be effectively protected, thereby improving the reliability of a product and prolonging the service life of the product.

Description

technical field [0001] The invention belongs to the technical field of power supply detection, and in particular relates to a detection method for detecting whether an AC power supply is cut off and a power failure protection method for a DC frequency conversion compressor designed using the detection method. Background technique [0002] AC mains or three-phase power failure detection is not a new technology, and has been widely used in various fields such as industry and agriculture. For example: in the field of aquaculture, if the power is cut off for a long time, the oxygen supply of the water body is insufficient, which will cause a large number of fish and shrimp to die; in the field of cold storage, once the cold storage is powered off, it will affect the shelf life of the stored products; In the field of management, once the computer room is powered off, the UPS power supply is required to start immediately to meet the continuous power demand of the computer room, et...

AI Technical Summary

Problems solved by technology

This detection time t is sufficient for ordinary AC power detection applications, but it is not enough for applications such as DC inverter air conditioners that use inverter power

Because at the moment of AC power failure, if the corresponding protection measures cannot be detected and implemented in time, the permanent magnet inside the DC inverter compressor will be demagnetized or the magnet inside the intelligent power module IPM (Intelligent Power Module) in the inverter power supply will be damaged. Inverter components, resulting in the failure of the whole product

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