Single Phase Brushless Dc Motor Control System Without Position Sensor

According to the number of phase number, brushless dc motor can divided into two kinds:single phase brushless dc motor and multiphase brushless dc motor. Along with the rapiddevelopment of modern science and technology, which include the power electronic technology,control theory and computer technology, and combined with the new development of rare earthpermanent magnet materials, multiphase brushless dc motor have more wider application fields.But in small power applications, especially for the motor rapid response capability and speedcontrol accuracy is not high, but to control the cost comparison sensitive products, such as airblower, the copy machine, computer hard disk drives and others, multiphase brushless dc motorlost their advantage. Single phase brushless dc motor control with low cost, simplemanufacturing etc, and therefore very suitable for application in these areas. At present, in China,few researchers have single phase brushless dc motor control, especially in the sensorless control.The studies are as follows:First of all, the paper on the detailed analytical single phase brushless dc motor structureand working principle is established, on the basis of the mathematical model, and inMatlab/Simulink window under established single phase brushless dc motor control system forsensorless simulation model of single phase analysis of brushless dc motor for sensorless controlcharacteristic laid a foundation.Second, the paper analyzes/contrasts the traditional motor starting and rotor positiondetection and the advantages and disadvantages of the methods. On this basis, this paper putsforward the points based on double closed loop three-phase reuse method. And the controlmethods of traditional compared, the method can reduce the output of the motor torque ripple,expand the motor speed range, obviously improve the working efficiency of the motor. In orderto better control single phase brushless dc motor control strategy, this paper analyzes the changeduring phase of the three-phase waveform. In addition the current double closed loop speedcontrol strategy to improve the dynamic performance of motor, and insert for current loop, outerring for speed. Finally, this paper introduces the design of the dsPIC30F2010based on single phasebrushless dc motor for sensorless double closed loop control system. For the control system ofhardware and software design makes detailed discussion; Discusses several major hardwarecircuit design process, the paper expounds the principle diagram design. Software of firstdiscusses the overall design, then detailed describe software to realize to pay attention to severalproblems and main procedure design diagram.The experimental results show that the design of the proposed method has good three-phasereuse time performance of speed adjustment and smaller output torque fluctuations, the systemstarting fast, stable operation and has a wide speed range. Especially with double closed loopcontrol, can significantly improve the dynamic performance of the motor, and got a very goodcontrol effect.