Desenvolvimento de uma bancada de teste de tração para motores brushless cc aplicado ao aerodesign

Abstract

In the preliminary stages on an aircraft project development, it is necessary to test the propeller performance on the plane’s static traction force as well as the traction and power of the engine as a function of an operating speed range during flight. To obtain an aircraft with excellent performance qualities in SAE AeroDesign Brasil competition, it is fundamental that the available traction provided by the propeller be determined with the highest precision as possible and one of the techniques is by using a test bench for the motor. In 2020, it was introduced the possibility of electrical motorization in the regular category of the SAE AeroDesign Brasil competition due to recent restriction with glow-type combustion engines. Then, it is observed the possibility to develop a Brushless DC Motor test bench, capable of performing all tests needed to assist the choice of the powertrain group in the project developed by AeroDesign UTFPR Curitiba. The control and power system design includes a Raspberry Pi +3B as the main controller unit and an Arduino Uno board for interfacing with sensors and peripheral circuits. The controller unit is responsible for processing the values of the sensors and Front-End interface, in addition to the Brushless DC motor drive signal. The auxiliary controller board has an interface for a 5 kg load cell, Pitot tube for measuring air speed, Hall effect sensor for reading engine propeller speed, sensors for monitoring voltage, current and temperature. The control software is based on the Node-RED tool for choosing parameters, identifying faults, and storing test settings and results. Static tests were performed for the APC 11x6” and WINDSOR S-1380 propellers in Open Loop and Turbo, Step and Peak modes, and dynamic tests for the second model with PWM modulation up to 50%, with the parameters of traction, rotation and power. The test in Open Loop Mode provided the user with controllability under the powertrain, with the engine traction data being consistent with the distributed PWM. Testing in Routine Mode is a great tool for comparing powertrain sets, which can be evaluated as differences in traction curves, power and rotation between propellers. The performance of dynamic tests was possible with the validation of the bench support system and also the use of the Pitot Tube to capture the air velocity. All the results prove that the main objective of the work was successfully achieved, being made available to the Electrical and Performance group for the AeroDesign UTFPR Curitiba team.