I am running an induction motor and a stepper motor simultaneously through a driver board I designed. The board has a dual H-bridge for driving a bipolar stepper motor, and an inverter for driving the induction motor. The DC voltage supplied to the dual H-bridge and the inverter comes from a bench supply, which is 25 Vdc. The bench supply supplies another 11 Vdc tothe gate driving ICs (IR 2112S).
The gate driving signals come from a micro-controller board, which also has the run-profile for the two motors including other logic.
Both motors run almost perfectly individually, and when running simultaneously, they work fine during acceleration and steady state phases of the program/recipe.
However there comes a time during the program/recipe when the stepper motor is running at full speed (max rated) and the induction motor starts to decelerate/brake. At a very specific point during the deceleration (almost precisely) the stepper motor (which was running fine at full speed stalls.
I can't find anything wrong with the program logic, so I am thinking of an electrical problem. I initially thought it could be crosstalk in the two sets of motor driving signals. But the stall comes at too specific a time to be just crosstalk.
My current theory is the current generated due to braking by the induction motor, becomes too large and interferes with the stepper motor. But I am not sure how to test and rectify this.
Any ideas would be welcome.