Modeling Research Base On The Real-time Measurements Of Ship Electric Propulsion Motor

Electric propulsion device has a huge advantage on ship field which traditional propulsion systems can't provide. Now it had become a hotspot research area both here and abroad. The real ship experimental and traditional offline parametric test methods have their limited value in ship research field because of their own defects.Real-time simulation technology was regarded as the highest confidence a simulation technology so that it became an inevitable trend in ship research field. This paper used the AppSIM real-time system which was invented in china to build a semi physical real-time simulation platform for studying the modeling and simulation of the ship electric propulsion system.According to the needs of project, the ship electric propulsion system was divided into a load module and the propulsion motor module after careful analysis,and then the paper build propeller load model and the reluctance Load device model of this project. Focused on the six-phase induction motor module, this paper analyzed its physical model, the equivalent circuit model and common mathematical model,and then put forward the related parameters identification of equivalent circuit model method. A general simplified model of the asynchronous motor was proposed to ease the later analysis. Actual motor has magnetic saturation phenomenon, the no-load test data was used by calculation before interpolation processing to correct magnetic saturation so that the model is closer to the actual motor.Good identification algorithms choice related to the success of the measured modeling strategy, least square method became the preferred method for the advantages in engineering application. This paper deduced the steady speed linear model and the wide speed range linear model because of the least squares can only be used for linear system identification, and the simulation results verified that the latter has more advantages. Aiming at some defects of basic least squares, this paper respectively proposed adaptive least squares, reset least squares and multiple innovation least squares three kinds of improved algorithms, which also can be used in combination to achieve the better result. There were some shortcomings about the least square method in the field of non-zero mean noise, and some control methods demanded more accurate rotor resistance. This article used the simplified motor model to research; the rotor resistance had been set in the state variable state equation of the asynchronous motor, linearization by Jacobi matrix, realized using EKF for therotor resistance identification.In the last part, this paper through building the real-time simulation platform with AppSIM as the core base on the laboratory physical simulation of ship electric propulsion system, used the identification arithmetic which combines restorable and adaptive and multiple innovation least square method to achieve high-precision measurement of three-phase asynchronous motors modeling technology. This study paved a way not only for the study of control strategy in this project, but also for engineering application and system evaluation for the follow-up works which had a certain practical value.