Research On Modeling And Control Technology Of The Six-Phase Induction Machine

Along with the rapid development of semiconductor technology and power electronic devices, multi-phase induction machine has been replaced the three-phase motor gradually due to its advantages like low DC power supply, low torque ripple, high reliability in the high-power control fields. Then more researchers have focused on control strategies about the multi-phase induction machine. This paper has mainly researched on mathematical models of the six-phase induction machine, SVPWM control strategy and machine operation under one-phase fault conditions and has established the open-loop control system of the six-phase induction machine.Firstly, this paper analyzes the structure of the six-phase induction machine and gets the three coordinate systems and decomposition transformation matrices after the space vector decomposition, then, the machine has been decoupled from6dimension to three vertical harmonic subspaces and mathematical models have been built. Under the MATLAB environment, simulation models and the machine characteristics have been performed.Secondly, according to the topology of the inverter used in the six-phase control system, this paper introduced the SVPWM control strategy. Aimed at the shortage of the traditional SVPWM algorithm, a new SVPWM control strategy based on the12maximal vectors has been proposed. In the paper, the realization and improvements have been given and in order to ensure the accuracy of this algorithm the simulation model has been build in MATLAB.Thirdly, this paper has discussed the machine from machine modeling to the space vector decomposition and then gets the new sub-spaces and decomposition transformation matrices. Especially this paper analyzed the expression of the electromagnetic torque in details and finds the inherent torque ripple under the machine operation under one-phase fault conditions. The SVPWM under faults conditions can be derived from researching the effective voltage vector. Besides, the simulation models and the corresponding SVPWM control strategy under one-phase open have been build in MATLAB and its results verified the torque ripple and the feasibility of control scheme.At last, this paper describes software and hardware design of the six-phase induction machine open-loop control system, completes the software realization and simulation with DE2(FPGA development board) and makes detail analysis on the frequency detection, SVPWM algorithm and faults detection modules. Finally, some experimental results on the hardware control system are given and analyzed.