Regenerative Braking Controller for Electric Motors

Abstract

A method of regenerative braking includes providing an electric motor including at least one stator and a rotor, a speed of the rotor, a motor controller that regulates a current level in the stator winding, a power inverter which controls an energy flow to the stator terminal, and an energy storage system (ESS) which exchanges energy with the motor. A battery management circuit is between the power inverter and the ESS, and a processor has an associated memory storing a regenerative braking (RB) algorithm. The RB algorithm during braking causes the motor controller to execute determining an RB torque value from the rotor speed that maximizes regenerative braking current, and the power inverter is used to redirect the RB current to maximize a power transfer from the motor to the ESS.

1 . A non-transitory computer-readable medium storing instructions that when executed on a computing system causes the computing system to:
 determine a value for regenerative braking torque (RB torque value) from a rotor speed of an electric motor that maximizes a level of a RB current (maximum RB current), and   use a power inverter to redirect the maximum RB current to maximize a power transfer from the electric motor to an energy storage system (ESS).   
     
     
         2 . The method of  claim 1 , wherein the electric motor comprises a permanent magnet (PM) motor. 
     
     
         3 . The method of  claim 1 , wherein the electric motor comprises an alternating current (AC) induction motor. 
     
     
         4 . The method of  claim 1 , wherein the motor controller implements field-oriented control (FOC).