Air conditioner and variable frequency motor thereof

Abstract

The invention relates to an air conditioner and a variable frequency motor thereof. A driving circuit of the variable frequency motor comprises a three-phase rectifying circuit, a voltage collecting module, a current collecting module, a capacitor and an inverter circuit; and the voltage collecting module, the capacitor and the inverter circuit are connected to the output end of the three-phase rectifying circuit; a three-phase winding is connected between an upper bridge arm and a lower bridge arm of the inverter circuit; the current collecting module is located between a negative electrode of the capacitor and the lower bridge arm; a control module is used for outputting a pulse opening signal to one of the lower bridge arms to obtain current detected by the current collecting module; and when the current collecting module detects that the current exceeds a current set threshold, it is judged that the variable frequency motor leaks electricity. Therefore, only one pulse turn-on signal is input to the lower bridge arm, the turn-on time is shortened; a BOOST circuit formed by the motor winding, a lower bridge arm switch tube and an upper bridge arm anti-parallel diode is utilized; leakage protection is achieved by detecting a bus voltage, the device stress is extremely low, no hardware circuit needs to be added, and the cost is saved.

Description

technical field [0001] The invention relates to the technical field of frequency conversion motor leakage detection, in particular to an air conditioner and a frequency conversion motor thereof. Background technique [0002] When the air conditioner compressor is in standby state, the compressor winding or connecting wire may be grounded due to external force interference or corrosion. The inverter needs to identify it in time and take a shutdown action to protect the device from damage. [0003] Such as figure 1 As shown, it is an existing general-purpose inverter compressor drive circuit, and the potential of the negative electrode of the electrolytic capacitor is lower than 0 (ground). Assuming that the U phase is grounded when the compressor stops (the coil insulation is damaged or the power line terminal falls off), the potential at U0 is 0 at this time. The traditional leakage protection process of the compressor generally directly turns on the lower bridge arm or al...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a variable frequency motor and an air conditioner, which solves the technical problem of how to reduce the damage rate of devices in leakage protection by improving the control mode without changing the hardware circuit of the variable frequency motor drive circuit in the prior art

Images