A motor driving apparatus applicable to various types of motor driving
apparatuses and having a power storage section for storing a regenerative
current and supplying power to an inverter section at the time of
acceleration. The motor driving apparatus further comprises a converter
section, a DC link, and an inverter section, thereby driving a motor.
Connected to the DC link is the power storage section including a
capacitor, a charging circuit, a discharging circuit and a diode. The
regenerative current produced at the motor deceleration is stored in the
capacitor through the diode. The power stored in the capacitor is
outputted to the DC link by turning a switching element of the
discharging circuit ON at the motor acceleration. Furthermore, the
charging circuit has a boost switching regulator circuit for charging the
capacitor to the given upper limit voltage equal to or larger than
voltage of the DC link and a current limitation circuit for limiting a
charging current to the given upper limit. The upper limit of the
charging current can be changed according to the type of the motor
driving apparatus.