Total_newbie
Member
We have a DC Drive (ABB DCS800) which is running a load (initially) at a fixed speed. For testing purposes, we want to simulate a different inertial load on the machine at the time that we apply a mechanical brake (simulated inertia). We achieve this by switching (after we achieve a given speed) to torque control - and then adding or reducing torque in order to achieve a target acceleration/deceleration while brake is applied.
I would like to determine the maximum simulated inertia which we can achieve with drive. If we are adding inertia (= positive torque), I believe that this calculation is relatively simple. I know max torque that drive can put out (at base speed), and I can use this value to determine max torque which I can add (assuming we are at or below base speed) to simulate a greater inertia. My question is how much reverse (braking) torque the drive can put out when it is rotating in forward direction. My impression is that this should be independent of present (forward) speed. Can I assume that I can get max torque in reverse direction in this case? (I think that this is quadrant 2 - forward braking). And - there must be some switching time which is required to go from positive torque to negative torque. I cannot find this though in specs.
Any clarification of these issues would be greatly appreciated!
I would like to determine the maximum simulated inertia which we can achieve with drive. If we are adding inertia (= positive torque), I believe that this calculation is relatively simple. I know max torque that drive can put out (at base speed), and I can use this value to determine max torque which I can add (assuming we are at or below base speed) to simulate a greater inertia. My question is how much reverse (braking) torque the drive can put out when it is rotating in forward direction. My impression is that this should be independent of present (forward) speed. Can I assume that I can get max torque in reverse direction in this case? (I think that this is quadrant 2 - forward braking). And - there must be some switching time which is required to go from positive torque to negative torque. I cannot find this though in specs.
Any clarification of these issues would be greatly appreciated!