| 摘要 |
PROBLEM TO BE SOLVED: To provide a power conversion device capable of being downsized to solve the problem in which a semiconductor switch for processing regenerative energy as thermal energy, a resistor for braking, and a control circuit thereof are required when an induction motor is decelerated.SOLUTION: A power conversion device comprises: a forward converter which converts AC power to DC power; a DC intermediate circuit which smooths the DC power converted by the forward converter; a reverse converter which converts the DC power smoothed by the DC intermediate circuit to AC power of any frequency; a control circuit which controls a switching element of the reverse converter; and a driving circuit which drives the switching element of the reverse converter. The control circuit calculates a slip using a primary resistance value R1, a secondary resistance value R2, a primary current value i1, and an excitation current value im of an induction motor, and uses a voltage obtained by adding a voltage of a frequency component not more than the frequency corresponding to the slip as output voltage when the induction motor is in a deceleration state or in a regeneration state. |
