dq - Starting CurrentReduction Method and device of Single-phase Induction Motor Based on dq-axis Transformation

摘要

The present invention relates to an apparatus for limiting an inrush current of a capacitor operation-starting type single-phase induction motor based on a virtual dq-axis and a method thereof. According to the present invention, the apparatus comprises: a rectifier converting inputted single-phase commercial 220V/60Hz AC power into DC power; a DC stabilization smoothing capacitor connecting one or more condensers to an output terminal of the rectifier in parallel to stabilize the DC power rectified in the rectifier; a full-bridge inverter (FBI) having a PWM inverter function which is connected to the output terminal of the DC stabilization smoothing capacitor to convert the DC power into AC power through the full-bridge inverter and controls the single-phase induction motor; a capacitor operation-starting type single-phase induction motor connected to an output terminal of the full-bridge inverter; a full-bridge switching signal and voltage/current sensor circuit generating a switching signal to control the full-bridge inverter and the single-phase induction motor and monitoring current and voltage information of the full-bridge inverter and the single-phase induction motor in real-time through a current/voltage sensor circuit; and a system control unit for controlling the entire system including such components. Accordingly, when an inrush current is generated upon starting the capacitor operation-starting type single-phase induction motor using a virtual dq-axis current, the apparatus provides a unique effect capable of preventing distortion in a phase angle followed by a phase error which is generated by degradation of a capacitor and a difference in a blocking frequency of an operation all-pass filter (APF) of an auxiliary device.