Brushless DC motor and control system for EEG-3 crossing barier drive

This paper presents the design and selected test results of a brushless DC motor and control system designed for the railroad crossing barrier drive EEG-3. The magnetic circuit calculations of the motor were conducted using finite element program – FEMM 4.2. The stator and rotor plates of the motor were made by laser cutting. Such technology makes it possible to place the magnets inside the rotor, which significantly simplifies the rotor fabrication technology and ensures the certainty of magnet attachment. To control the position of the rotor relative to the stator, three slot optocouplers were used, which cooperate with the with the motor control system. The control system uses a low-voltage inverter whose transistors are controlled by a microprocessor. This microprocessor interacts with external signals — "up" and "down" — which open or close the railway crossing, as well as with limit switches that stop the drive once the upper or lower end position is reached.