Patent attributes
A motor drive system includes a converter configured to convert power between AC power in a power source and DC power in a DC link, an inverter for drive configured to convert power between the DC power in the DC link and AC power serving as drive power or regenerative power for a servomotor for drive, a motor control unit for drive configured to control the servomotor for drive connected to the inverter for drive, a power storage device configured to store the DC power from the DC link or to supply the DC power to the DC link, and a base holding energy change unit configured to change a base holding energy defined as a reference value of a holding energy of the power storage device, in accordance with the holding energy of the power storage device.