Research On Permanent Magnet Synchronous Motor Control System For Hybrid Electric Buses

With the increasing number of cars, the traditional fuel cars provide convenienceto our life, which also lead to more and more environmental problems and energyissues, so the development of new energy vehicles become an effective way toalleviate these problems. Hybrid buses have the advantages of traditional fuel busesand blade electric buses, and it has received more and more attention, the motor drivesystem applied in hybrid buses has become a hot research area.Hybrid buses have complex working conditions and changing load, which resultin permanent magnet synchronous motor parameters (PMSM) fluctuate within acertain scope. To reduce or eliminate the parameter variations affect the performanceof hybrid electric bus, it is necessary to identify the parameters of PMSM. In view ofthe problem caused by traditional parameter identification methods, This paperproposes an improved parameter identification method, the off-line identificationparameters results as the initial value of online identification, thereby enhancing theonline identification process parameter convergence speed. A simulation model ofthe identification system has been set up in Matlab/Simulink platform, the simulationresults show that the proposed method can effectively improve the convergence speedin the process of parameter online identification.In the permanent magnet synchronous motor drive system, power switchingdevices has always been a weak link, once it fails, the motor may be out of control,and result in disastrous consequences, so it is necessary to study on fault-tolerantcontrol of permanent magnet synchronous motor drive system. In this paper, severalcommon fault-tolerant topology were compared and analyzed, and select the three-phase four switches tolerant topology research. Aiming at the shortcomings of thetraditional three phase four switch topology, this paper presents an improved switchthree phase four switches fault tolerant topology, Three-phase four switches ofSVPWM algorithm and its essence has been explored, to reduce the current and torquepulsation, a voltage vector optimization configuration mode was designed, and set upa three phase four switches fault tolerant control system simulation platform, verifiedthe related principle and algorithm.Based on TMS320F28335, a system hardware experimental platform has beenset up, and also designed the relevant software program, and did some experiments,the results showed that the experimental platform has good performance.