Managing regenerative energy of reciprocating pumping unit

A method of operating a pumping unit having an electric motor to reciprocate a downhole pump with a rod string, the method comprising:

• stroking the pumping unit in strokes by driving the electric motor with a variable frequency drive;
• measuring operational parameters of the pumping unit using sensors associated with the pumping unit;
• determining, based on the operational parameters, at least one straightway speed and at least one cornering speed for the strokes of the pumping unit;
• controlling the variable frequency drive to drive the electric motor by:
• decelerating the strokes of the pumping unit in a deceleration from the at least one straightway speed toward the at least one cornering speed, and
• accelerating the strokes of the pumping unit in an acceleration from the at least one cornering speed toward the at least one straightway speed;
• storing regenerative power in a capacitor bank in electrical connection to the variable frequency drive, the regenerative power being produced during the deceleration;
• and
• supplying stored power from the capacitor bank to the variable frequency drive to at least partially drive the electric motor during the acceleration.