Dynamic control of the permanent magnet assisted reluctance synchronous machine with constant current angle

[摘要] This thesis is about the dynamic control of a permanent magnet assisted reluctance synchronousmachine (PMA RSM). The PMA RSM in this thesis is a 110 kW traction machine and is ideal for theuse in electrical rail vehicles. An application of the dynamic control of the PMA RSM in electrical railvehicles is to reduce wheel slip.The mathematical model of the PMA RSM is derived and explained in physical terms. Two methodsof current control for the PMA RSM are investigated, namely constant field current control (CFCC)and constant current angle control (CCAC). It is shown that CCAC is more appropriate for the PMARSM.A current controller for the PMA RSM that guarantees stability is derived and given as an analyticformula. This current controller can be used for any method of current control, i.e. CFCC or CCAC.An accurate simulation model for the PMA RSM is obtained using results from finite element analysis(FEA). The accurate model is used in a simulation to verify CCAC. A normal proportional integralspeed controller for the PMA RSM is designed and the design is also verified by simulation.Practical implementation of the current and speed controllers is considered along with a generaldescription of the entire drive system. The operation of the resolver (for position measurement) isgiven in detail. Important safety measures and the design of the electronic circuitry to give protectionare shown. Practical results concerning current and speed control are then shown.To improve the dynamic performance of the PMA RSM, a load torque observer with compensationcurrent feedback is investigated. Two observer structures are considered, namely the reduced stateobserver and the full state observer. The derivation of the full state observer and the detail designs ofthe observer elements are given. The accurate simulation model of the PMA RSM is used to verify theoperation of the observer structures and to evaluate the dynamic performance. Both observerstructures are implemented practically and practical results are shown.One method of position sensorless control, namely the high frequency voltage injection method, isdiscussed in terms of the PMA RSM. This work is additional to the thesis but it is shown, because itraises some interesting questions regarding the dynamic control of the PMA RSM.

[发布机构] Stellenbosch University