Research Of Novel Doubly Salient Memory Motors

Memory motors take good advantage of the Written-poleTM motor to develop a new class of controllable flux permanent magnet (PM) motors. The AlNiCo PMs are used due to the high remanence and low coercive fore and a unique sandwich rotor structure is smartly designed so that the magnetization states of AlNiCo PMs can be easily changed by several de and remagneting current pulses while immune from the q-axis current. However, as a novel kind of PM motors, the research progresses including motor topology design and numerical analysis methods are slow and experimental results are also limited in no load performances. Against this background, a deep and comprehensive study has been done for the development of memory motors. Three creative contributions have been proposed: the concept of doubly salient memory (DSM) motors has been firstly proposed; a time stepping finite element method coupled with hysteresis model has been built; the transposition design method have benn firstly proposed to solve the problem of asymmetric among phases of DSM motors.Firstly, a novel memory motor, DSM motor, which combines the concept of PM flux controllability and merits of doubly salient PM (DSPM) motor is presented.Secondly, compared with experimental results, the calculated totally demagnetization magnetic motive force (MMF) of the prototype of the memory motor using magnetic circuit method is ooverestimated much. To ensure the accuracy, a field circuit time stepping finite element method coupled with the parallelogram hysteresis model is employed and both no load and load characteristics are simulated in an accurate way.Thirdly, to verify the validity of the proposed parallelogram hysteresis model, the Preisach hysteresis model whose accuracy in simulating the hysteresis effect has been accepted is applied to analyze the DSM motors. The adoptive Preisach hysteresis model is deducted through smartly functions transformation and does not needs considerable statistical test data which are necessary in general Preisach hysteresis model.Fourthly, one new method which is called transposition design method is proposed to radically solve the asymmetric problem among phases in DSM and hybrid field DSPM motor with traditional structures. A three phase, 24/28 DSM motor is designed and analyzed in detail.Fifthly, so far the experimental research about memory motors are all concentrated on the static no load flux adjustment. In this thesis, two set of general drive and control circuits hardware are designed and built for the 5 phase 30/24 and 3 phase 24/28 DSM motors. The transient no load and natural characteristics are measured and several application test are also preliminarily executed.Finally, as a true flux controllable PM motor, there is no doubt that the memory motor occupies a very important position in the development of PM motors. However, the progress of this kind of motors is slow duo to its unique design principles and difficult analysis methods. In this thesis, a series of research achievements provide a powerful reference tool for the future design and analysis in topology, experiments and numerical realization.