The invention provides snubbing apparatus for a D.C. motor in which a capacitor which is charged while the motor is rotating in a first direction is discharged into the gate of a thyristor to initiate the snubbing action. When the thyristor goes on a field coil is connected in series with the motor armature, so as to place the motor in a regenerative mode and snub the motor.
Emergency braking device for a brushless motor comprising damping means connected through a switch to the windings of the brushless motor in case of emergency to dissipate the energy stored in the inductance of the windings of the brushless motor. The impedance characteristics of the damper means are optimized by selecting a capacitance which has a predetermined relationship to the inductance of the motor winding.
A system is disclosed for recovering and storing the energy generated by an electrical motor during deceleration so as to be available for use when the motor is subsequently accelerated. The system utilizes a capacitor for storing the energy produced by voltage regeneration of the motor when decelerating. A two-quadrant regulator, connected between a three-phase rectifier and a four-quadrant SCR regulator, controls the charging and discharging of the capacitor so that the energy stored therein is proportional to the energy required to accelerate the motor and load to the maximum rotational velocity required.
