The Study On Applications Of Brushless Brushless DC Motor In Field Refrigerator Compressor

The most advanced field low-temperature refrigerator of foreign armies,with brushless DC compressor adopted, is gifted with small volume, highrefrigeration efficiency and anti knock performance, and thus can be used forblood refrigeration and blood components transportation, which means thetrend for the development of refrigeration technology.The People’s Liberation Army（PLA）adopts civilian refrigerator with ACcompressor in field condition, which has low temperature control ability andthus can not adapt itself to field environment. With the development ofelectronic technology and IT, the advanced refrigeration technology,temperature detection&control system, digital temperature display andrealtime recording system are integrated into the design and manufacture offield low-temperature refrigerator. The investigation, based on the servicerequirements of field low-temperature refrigerator of the PLA, puts forward thetactical&technical indexes and control system for the brushless DC motor.In the investigation, the structure and working principle of the brushlessDC motor are introduced, and its mathematical model and controlcharacteristics are analyzed.Several control methods for brushless DC motor without position sensorare compared, and the control principle of back-Electromotive Force (EMF)brushless DC motor is analyzed in detail. The control system forback-EMF-method-based brushless DC motor without position sensor isdesigned, and the components of the circuit and the anti-jam measures for thesoftware and hardware are introduced.The field low-temperature refrigerator, using brushless DC motor withoutposition sensor, can adapt itself to the harsh or complicated environment for itslow power, high refrigeration efficiency and alternative power supply by thevehicle, which is theoretically and practically significant for militarylow-temperature issue supply at wartime and peacetime.