This is a brushless DC motor controller board designed to control a Powerex (Mitsubishi) IGBT Intelligent Power Module (IPM). It can power up to a 50 HP brushless DC motor, depending on the selected IPM. The board controls both motor power and regenerative braking and can be set for speed (voltage) control or torque (current) control in software.

The board is based on a Unitrode UC3625 motor controller IC controlled by an Arduino Micro microcontroller. The Arduino acts as an interface between the UC3625. The Arduino can be programmed to validate user commands, establish control limits, set startup policies, detect faults, etc. User commands (throttle, brake) as well as feedback (motor speed and current) are sent to the Arduino analog inputs A0-A3. The 12-bit digital motor speed command on output pins D2 and D3 is sent to an MCP-4725 digital to analog converter which sends the motor current command to the UC3625 pin 1.

Careful attention is paid to the independent isolated motor phase gate drive circuits, which are designed to reduce the effects of PWM switching noise. Each circuit is isolated using Murata NME1215 isolated DC-DC converters and Avago ACPL-6800 Gate Drive optocouplers. LEDs indicate power and fault conditions in the gate drive circuits.

Motor current feedback is accomplished using a LEM HTB 50-P/SP5 Hall effect current sensor soldered through hole from the bottom of the board. The ground side of the power circuit (e.g. battery cable) should be threaded through this sensor. This minimizes losses in the power circuit. The board plugs onto the IMP using Hirose DF10-31S-2DSA(59) dual row connector, which solders through hole to the bottom of the board. The control board is powered by an external 12V supply.

The schematic sections are included as images above. 

A nice application note fo the UC 3625 can be found here:

http://www.ti.com/lit/an/slua083/slua083.pdf

Example Intelligent Power Module : Mitsubishi PM50RLA060: 

https://www.mitsubishielectric-mesh.com/products/pdf/PM50RLA060_e.pdf

You can leard about controlling Intelligent Power Modules here: 

http://www.pwrx.com/pwrx/app/IntellimodIntellPwrMods.pdf

LEM Hall effect sensor: 

http://www.lem.com/docs/products/htb_sp5_e.pdf

MCP-4725 DAC:

http://ww1.microchip.com/downloads/en/DeviceDoc/22039d.pdf

Arduino Micro:

https://store.arduino.cc/usa/arduino-micro

Final thoughts: Always take appropriate safety measures when working with high voltages and currents.

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