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Message: <blockquote data-quote="mdbuilder" data-source="post: 28152" data-attributes="member: 2245">Found on the internets:When the speed of the motor is more than the synchronous speed, relative speed between the motor conductors and air gap rotating field reverses, as a result the phase angle because greater than 90° and the power flow reverse and thus regenerative braking takes place. If the source frequency is fixed then the regenerative braking of induction motor can only take place if the speed of the motor is greater than synchronous speed, but with a variable frequency source regenerative braking of induction motor can occur for speeds lower than synchronous speed. The main advantage of this kind of braking can be said that the generated power is use fully employed and the main disadvantage of this type of braking is that for fixed frequency sources, braking cannot happen below synchronous speeds. In English, you are trolling along at say 5,000 motor rpm in B mode. You lift off the gas a little and the inverter says "Let's change the rpm to 4,800" the 200 RPM difference between actual motor rpm and commanded rpm results in reversed energy flow. Lift off more, commanded rpm goes down and braking force increases.</blockquote>