Compact eBike Drive

This prototype power electronics device was developed to meet a need for a compact, low-power permanent magnet DC motor drive intended for electrification-assisted bikes at a variable voltage range of 12 to 48 volts. This design iteration was developed with the focus on small form factor, and ease of development of experimental DC motor control routines.

The product comprises of two circuits - a power board and controller board. The controller board provides digital control in the form of a Texas Instruments TMS320 C2000 processor, which is a popular choice of system-on-chip (SoC) for power electronics applications. The controller communicates with an external host via CAN network, which allows for logging of low-bandwidth data such as DC bus voltage, detected motor speed, and inferred wheel torque.

The power board is capable of full 4-quadrant operation - meaning that the motor can be operated in both motoring and regenerative-braking modes, in both forward and backward directions. The drive enclosure is utilised as the sole heatsink for the power MOSFETs, and the entire drive is powered from a single DC energy source. Total galvanic isolation exists between the controller and power stages, making the power module easily revisable to higher voltage or higher power designs.