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This paper describes the integrated modeling of a permanent magnet (PM) motor used in an electromechanical actuator (EMA). A nonlinear, lumped-element motor electric model is detailed. The parameters, including nonlinear inductance, rotor flux linkage, and thermal resistances, and capacitances, are tuned using FEM models of a real, commercial motor...
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My research work is in the field of studies of the dynamic behavior of a power system and electrical machine and to highlight the presence of chaotic behavior. Knowledge of some methods developed to identify, delete, synchronize and even induce chaotic behavior in different non-linear dynamical systems, would inspire and develop some applications t...
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Preliminary investigations of nonlinear modeling of aircraft synchronous generators using neural networks are presented. Aircraft synchronous generators with high power density tend operate at current-levels proportional to the magnetic saturation region of the machine's material. The nonlinear model accounts for magnetic saturation of the generator, which causes the winding flux linkages and inductances to vary as a function of current. Finite element method software is used to perform a parametric sweep of direct, quadrature, and field currents to extract the respective flux linkages. This data is used to train a neural network which yields current as a function of flux linkage. The neural network is implemented in a Simulink synchronous generator model and simulation results are compared with a previously developed linear model. Results show that the nonlinear neural network model can more accurately describe the responsiveness and performance of the synchronous generator. The synchronous generator under test is a 200 kVA output power, 12 krpm rotational velocity design.
In all-electric aircraft, electromechanical actuators (EMAs) will be used to replace hydraulic actuators. Due to the highly transient mission profiles of the aircraft operation, thermal management of EMAs is a significant issue. In this paper, we study the heat problem of the control and drive units of EMAs, and build a model to calculate and simulate the power loss and heat generation in the driver board. The driver unit consists of a power inverter, a capacitor, a power dissipating resistor and a control circuit. The power loss of each component is studied. The heat loss in the power inverter comes mainly from the power switches: IGBTs. The on-state loss is proportional to the current of the motor, and the switching loss is determined by the switching frequency as well as current. The power loss in the power dissipating resistor is determined by the regenerative power, the capacitor and the control algorithm to stabilize the bus voltage, which varies from different mission profiles and different applications. All those parameters can be obtained in our simulation code. The power loss on the control circuit is negligible compared with the power loss on IGBTs and the power dissipating resistor, and generates very little heat in the system. A physical model is developed to estimate the heat loss on the motor driver unit, and a simulation model is built in Simulink software. Stator currents and voltages are input variables to the code. The power losses on the power inverter and unloading resistor are calculated, as is the total power loss. Experimental data from a 325 seconds long mission profile test is used to verify the model. Power input (current and voltage) to the electric motor is measured and used as input to our model. The power losses in the driver unit is calculated and used to estimate the temperature field of the electronic unit. The temperature results are compared with those measured by the thermocouples embedded in the driver unit.
