Exploring design of universal propeller simulator for airship propulsion system's driving motor

Rare earth permanent magnet brushless direct current motor is the energy conversion device between power system and propeller of high-altitude airship. Its performance has a profound effect on the overall performance of the high-altitude airship. Limited by the output torque of the permanent magnet brushless direct current motor, propeller on the ground cannot reach the rated angular speed when propeller works at high altitude, so it is difficult to carry on rotation test on the ground. In addition, performances of the permanent magnet brushless direct current motor system such as control accuracy, reliability and efficiency cannot be tested. The functional level of the motor load simulator is proposed considering the dynamic properties of the propeller and the basic functions of the propulsion system. Different loading actuators are evaluated and the conceptual design of the load simulator is accomplished. Inertia is realized by relatively small flywheel and inertia electrical emulation method. Torque is simulated by servo motor that can work at braking state and thrust is exerted on the motor by hydraulic servo valve control system. Finally, depending on the proposed scheme and design parameters, co-simulation model of the load simulator is established utilizing software MATLAB/Simulink and AMESim. After comparing co-simulation results with real propeller properties, the feasibility of the conceptual design of permanent magnet brushless direct current motor load simulator is proved, and what is more, the effectiveness of control strategies and the rationality of parameters settings for co-simulation are testified.