Self-Built 200V DC Brushed Motor Controller Demo
Sorry in advance for the poor audio quality. There is a server rack running in the background.
The details:
A prototype 200V DC brushed motor controller I built a few years back for an electric go-kart I have been working on. The version I am demoing is one of 4 major versions I created since the beginning, working out all the major issues, while learning how DC motor control works. Built to handle up to 20kW, but will only be used at around 3kW. As I mentoined, this is just a prototype, not a finished product. It works flawlessly, even under load, but still needs proper forward/reverse capabilities and regen capabilities. I have plans to completely rebuild it from the ground up until it has the exact feature set I desire.
The controller is based around an APTM50AM24SC MOSFET power module. The microcontroller is an Atmel Atmega 168 on an Arduino Pro Mini module. The controller features current limiting and acceleration profiles to prevent massive inrushes of current. Precharging is added to prevent damage to the 6000uF capacitor bank. The capacitor bank is oversized, but it was intended. The current sensor is an ACS758 bidirectional 200A hall effect current sensor. The theoretical limits of this controller are 40kW (200V, 200A) peak if cooled properly for an unknown period of time or 20kW continuous (200V, 100A). Theoretically it could operate up to 250V without damaging the controller, but to keep the ratings in a safe zone I am pre-defining the limit to 200V. The MOSFET module and other components could handle up to 130V more if the controller is optimized a bit more.
When this controller was designed I planned to use a forward/reverse relay with a re-wrapped coil to control the forward and reverse settings (only switched while no current is flowing), but have since decided it would be a better idea to remove the relay and go for an h bridge configuration instead. I want to eliminate any possibility of the relay disengaging when it should or shorting internally.