Air conditioner and compressor protection circuit thereof

Patent metadata

Field	Value
Publication number	US-9780555-B2
Application number	US-201415110099-A
Country	US
Kind code	B2
Filing date	Dec 30, 2014
Priority date	Apr 2, 2014
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

An air conditioner and a compressor protection circuit thereof are provided. When overcurrent occurs in a phase current of a compressor, an overcurrent level signal is output by a voltage comparison module, and is latched and output to an intelligent power module by a signal latching module, and the intelligent power module shuts off the output of the phase current according to the overcurrent level signal, so as to achieve the overcurrent protection of the compressor; and subsequently, a conventional level signal is output to the signal latching module by the voltage comparison module, the signal latching module keeps outputting the overcurrent level signal, and outputs the conventional level signal until a latching cancel signal output by a signal processing circuit is received, so that the intelligent power module starts the output of the phase current, thereby enabling the compressor to normally operate.

First claim

What is claimed is:

1. A compressor protection circuit, comprising: a current sampling module, a reference voltage generating module, a voltage comparison module, and an intelligent power module, the current sampling module sampling a phase current of the compressor and outputting a corresponding sampling voltage signal to a first input end of the voltage comparison module, the reference voltage generating module outputting a reference voltage signal to a second input end of the voltage comparison module, the voltage comparison module comparing the sampling voltage signal with the reference voltage signal; the intelligent power module controlling a working condition of the compressor according to a driving signal outputted by a signal processing circuit, when the intelligent power module shutting off the output, the intelligent power module outputting a fault protecting signal simultaneously, so that the signal processing circuit stopping outputting the driving signal; the compressor protection circuit further comprising a signal latching module;
an output end of the voltage comparison module being connected with an input end of the signal latching module, an output end of the signal latching module being connected with a testing port for protecting trigger voltage of the intelligent power module, a latching-controlling end of the signal latching module being connected with the signal processing circuit; when the sampling voltage signal being higher than the reference voltage signal, the voltage comparison module outputting an overcurrent level signal to the signal latching module, the signal latching module latching and outputting the overcurrent level signal to the intelligent power module continuously according to the overcurrent level signal, so that the intelligent power module shutting off the output of a phase current; when the signal processing circuit outputting a latching cancel signal to the signal latching module, the signal latching module outputting a conventional level signal to the intelligent power module according to the latching cancel signal, the intelligent power module driving the compressor to operate according to the conventional level signal and a driving signal outputted by the signal processing circuit.

2. The compressor protection circuit according to claim 1 , wherein the signal latching module comprises a latch, a latching-controlling circuit, the latch comprises a signal input pin, a signal output pin and a signal control pin, the signal input pin of the latch is defined as the input end of the signal latching module, the signal output pin is defined as the output end of the signal latching module; the latching-controlling circuit comprises a first input end, a second input end and an output end, and the first input end of the latching-controlling circuit is connected with the signal input pin of the signal latching module, the second input end of the latching-controlling circuit is defined as the latching-controlling end of the signal latching module, the output end of the latching-controlling circuit is connected with signal control pin of the latch.

3. The compressor protection circuit according to claim 2 , wherein the latching controlling circuit comprises:
a first resistor R 1 , a second resistor R 2 , a third resistor R 3 , a fourth resistor R 4 , a first transistor Q 1 ;
a first end of the second resistor R 2 is connected with the signal output pin of the latch, a first end of the third resistor R 3 is connected with the signal processing circuit, a second end of the second resistor R 2 and a second end of the third resistor R 3 and a first end of the fourth resistor R 4 are jointly connected with a base of the first transistor Q 1 , a second end of the fourth resistor R 4 and an emitter of the first transistor Q 1 are jointly grounded, a collector of the first transistor Q 1 and a first end of the first resistor R 1 are jointly connected with the signal control pin of the latch, a second end of the first resistor R 1 is connected with a direct current power.

4. The compressor protection circuit according to claim 2 , wherein the latching control circuit comprises:
a nand gate, a second transistor Q 2 , a first resistor R 1 , a fifth resistor R 5 , a sixth resistor R 6 , a seventh resistor R 7 , a eighth resistor R 8 ;
a first end of the fifth resistor R 5 is connected with the signal output pin of the latch, a second end of the fifth resistor R 5 is connected with a first input end of the nand gate; a first end of the sixth resistor R 6 is connected with the signal processing circuit, a second end of the sixth resistor R 6 and a first end of the seventh resistor R 7 are jointly connected with a base of the second transistor Q 2 , a second end of the seventh resistor R 7 and an emitter of the second transistor Q 2 are jointly grounded, a collector of the second transistor Q 2 and a first end of the resistor R 8 are jointly connected with a second input end of the nand gate, a second end of the resistor R 8 is connected with a direct current power; an output end of the nand gate and a first end of the resistor R 1 are jointly connected with the signal control pin of the latch, a second end of the resistor R 1 is connected with the direct current power.

5. The compressor protection circuit according to claim 2 , wherein the latching control circuit comprises:
a first resistor R 1 , a ninth resistor R 9 , a tenth resistor R 10 , an eleventh resistor R 11 , a twelfth resistor R 12 , a third transistor Q 3 , a fourth transistor Q 4 ; a first end of the tenth resistor R 10 is connected with the signal processing circuit, a second end of the tenth resistor R 10 and a first end of the eleventh resistor R 11 are jointly connected with the a base of the third transistor Q 3 , a first end of the ninth resistor R 9 is connected with the output pin of the latch, a second end of the ninth resistor R 9 , a collector of the third transistor Q 3 and a first end of the twelfth resistor R 12 are jointly connected with a base of the fourth transistor Q 4 , a second end of the eleventh resistor R 11 , an emitter of the third transistor Q 3 , a second end of the twelfth resistor R 12 and an emitter of the fourth transistor Q 4 are jointly grounded, a collector of the fourth transistor Q 4 and a first end of the first resistor R 1 are jointly connected with the signal control pin of the latch, a second end of the first resistor R 1 is connected with a direct current power.

6. The compressor protection circuit according to claim 2 , wherein the latching control circuit comprises:
a first resistor R 1 , a thirteenth resistor R 13 , a fourteenth resistor R 14 , a fifteenth resistor R 15 , a fifth transistor Q 5 , an inverter;
a first end of the fourteenth resistor R 14 is connected with the signal processing circuit, a second end of the fourteenth resistor R 14 and a first end of the fifteenth resistor R 15 are jointly connected with the a base of the fifth transistor Q 5 , a second end of the fifteenth resistor R 15 and an emitter of the fifth transistor Q 5 are jointly grounded, a first end of the thirteenth resistor R 13 is connected with the signal output pin of the latch, a second end of the thirteenth resistor R 13 and a collector of the fifth transistor Q 5 are jointly connected with an input end of the inverter, an output end of the inverter and a first end of the first resistor R 1 are jointly connected with the signal control pin of the latch, a second end of the first resistor R 1 is connected with a direct current power.

7. The compressor protection circuit according to claim 2 , wherein the latching control circuit comprises:
a first resistor R 1 , a sixteenth resistor R 16 , a seventeenth resistor R 17 , a eighteenth res

Assignees

• Midea Group Co Ltd

Inventors

• Bao Diansheng
• Chen Jianchang

Classifications

• H02H7/08 Primary

  for dynamo-electric motors · CPC title

• F25B2400/077

  Compressor control units, e.g. terminal boxes, mounted on the compressor casing wall containing for example starter, protection switches or connector contacts · CPC title

• F24F1/08

  Compressors specially adapted for separate outdoor units · CPC title

• F25B49/025

  Motor control arrangements · CPC title

• H02H7/09

  against over-voltage; against reduction of voltage; against phase interruption · CPC title