In a DC system, 4 quadrant is often, (ok, usually) but not always, regenerative. Not usually on an AC supply system.
4 quadrant symple means it can controll both accelleration and decelleration in both directions - hense - 4 quadrant. Dynamic braking in a 4 quadrant AC control generally sinks (dissipates) the decelleration power, while regenerative braking in a 4 quadrant DC system generally returns the braking energy to the source.Just my experience. 2 quadrant control can also be either regenerative or dynamic.
Please show me a circuit for 4 quadrant control of a DC motor from an AC supply that implements true regenerative braking. Explain how the output of the DC motor is syncronized to the ac line frequency. Then give me the name and manufacturer of the contoller, with specs on the amount of current it is capable of returning to the grid, and I'll believe you.
I am fully aware of DC regenerative 2 and 4 quadrant motor controls, and I know how an induction motor can be used as a generator, but I'd really like to know how to recover the power from my DC motor to the AC grid. (not just recover it into a battery)