Vermes
Advanced Member level 4
It is a BLDC motor controller for electric vehicle drive.
The system of inverter was based on si9979, which is a dedicated driver of BLDC motors to work with external power transistors. The power of the motor was rated at 1,5kW. Its main advantage is built-in planetary gear and a set of halotrons. The system si9979 has numerous protections including a protection against incorrect signal from halotrons and the possibility of engine braking by shorting one half of keys.
The entire vehicle can be powered by five tractions accumulators 75Ah and current 200A lead, what means that weight exceeded 200kg. Motor current control was made by its measure by the current transformer LEM. When the current exceeds a certain value, the comparator gave the signal to the overcurrent input of SI and detach the keys for a time set by RC constant. Speed control is a simple PWM.
The gas pedal from an English car was used as the manipulator. Dedicated circuits with optical isolation TLP521 control MOSFET transistors, and to generate three separate voltages for upper keys controllers – six DC-CD converters from old network cards connected in series. The whole circuit is powered by converter 12V-5V, 20V, +/-20V based on the tl494.
Housing was made of old car phone elements, adapted for this purpose.
Video of the device operation:
Pictures:
Link to original thread (useful attachment) – Kontroler silnika BLDC do pojazdu elektrycznego