Research On BLDCM System For Concentrically Indirect Driven Washing Machine

Brushless DC Motor has good speed control capability, high efficiency and low noise. It has many advantages when it is applied to washing machine .Now this has been recognized by many producers. The work of this thesis is to develop a low noise BLDCM drive system for indirect through speed reducer and clutch but concentric drive washing machine.Firstly, integrated design and characteristic calculation of the motor based on Ansoft software is introduced. Here Ansoft's finite element program is fully used to calculate some important parameters such as emf-coefficient and phase winding inductance. Also the relationship between emf-coefficient and characteristic of the motor is analyzed. With the parameters calculated the motor's mechanical characteristic is predicted.Secondly, optimization of magnet shape based on back-emf was brought out. The theory of magnet shape optimization is formulated first. Then two type method of magnet shape optimization were taken forward. Both these two methods were tested with designed motor. Some valuable conclusions are derived.Thirdly, design of simplified sinusoidal motor driving circuits using the Micro Chip dsPIC30F2010 as a processor is taken. It only has speed loop and the sinusoidal wave is produced by SVPWM. Hardware and software design are particularly described.Finally, speed control strategies under washing and spinning condition were analyzed. Also the performances of simplified sinusoidal and normal sinusoidal driving circuits were tested.