Research On The External Rotor PMSM Used For Fan Coil

China as the largest central air-conditioning market in the world, fan coil as for theend product matching permanent magnet synchronous motor with sensorless vector controltechnology is basically controlled by few companies for TOSHIBA of Japan and IR of theUnited States, they have been on implementation of technology monopoly to China, fancoil with permanent magnet synchronous motor market is completely monopolized byJapan and the United States. Based on this background, the topic take the most advancedtechnology of sensorless vector control in the world to research on outer rotor permanentmagnet synchronous motor used for fan coil, thus breaking the monopoly of similarproducts at home and abroad, to fill the gaps. The main contents of this paper are asfollows:First, this paper describes the background of the research and development status,detailed derivation of the mathematical model of the external rotor PMSM, the coordinatetransformation process, analysis of variety of permanent magnet synchronous motor vectorcontrol strategies, determined using the magnetic of field oriented control strategy in thetopic, and make a research on SVPWM. By studying and analysis of the principle of thesliding mode observer, we finish the design of the sliding mode observer which can knowthe conditions of the motor stator voltage and phase current, rotor position is estimated.Secondly, make a design of the control system of hardware and software. In the designof hardware, detail the function of the master chip XC836M, power driver circuit, currentsampling and amplifying circuit, DC bus voltage detection circuit, power supply circuit andspeed control circuit are designed. In the design of software, use the design of asub-module of thinking, detailed research and analysis of the main program, interruptprogram, the main program of the position estimation procedures, SVPWM procedures andcommunication procedures.Finally, the prototype of fan coil with external rotor permanent magnet synchronousmotor is tested, and the test results are analyzed. Grately, the results achieve satisfactoryresults which are expected.