5KW Smart Brushless DC Motor Drive


This is a high power 5KW smart Brushless DC (BLDC) motor drive for advanced robotics and industrial applications. Hexabitz designed the PCBs and developed both firmware and software. The drive is supplied with 3-phase 380V AC power input that gets regulated to 550V DC Bus voltage and then is inverted back to a 3-phase waveform to control the motor via an integrated gate drive and six power MOSFETs. Advanced Sensorless Field-Oriented Control (FOC) is implemented by measuring motor currents and estimating its speed and position without the need for expensive and unreliable encoders.

The drive has isolated industrial inputs and outputs. It is equipped with isolated Modbus RTU interface for advanced networking as well as a couple of environmental sensors (temperature, humidity). It features Bluetooth and WiFi wireless connectivity as well, and can be controlled via smartphone Apps (Android and iOS).

Project Skills

  • PCB Design
    • 3 x 2-layer PCBs
    • High power design (15A max, Input AC 3x380V, DC Bus 550V)
    • Isolated I/Os
  • Mechanical
    • 3D integration within motor frame
  • Firmware
    • Advanced closed loop motor torque/speed regulation using Sensorless (FOC) Control
    • Modbus RTU networking
    • Temperature/humidity sensors
    • Bluetooth/WiFi connectivity
  • Software
    • Android App
    • iOS App

Innovative Solutions


Challenge: The drive has high power components requiring voltage isolation and wide PCB traces and must fit inside the tight motor frame

Solution: We split the design into three PCBs that integrate geometrically with each other and within the motor frame