Nabtesco Corporation

Michael Haider

Dominik Bortis

Yasuo Ono

Johann Kolar

Kazuhito Nakamura

Miric Spasoje

Walter Johann Kolar

Johann W Kolar

A motor drive system includes: a first inverter connected to one end of an open-end winding of a three-phase motor, an input voltage from a single-phase AC power source being rectified into a rectified voltage and input to the first inverter; a second inverter connected to another end of the open-end winding and including a DC link capacitor; and a control unit that controls the first inverter so that a first inverter output voltage supplied from the first inverter to the three-phase motor is in phase with a motor current flowing in the three-phase motor, controls the second inverter to supply reactive power to the three-phase motor by making a second inverter output voltage supplied from the second inverter to the three-phase motor orthogonal to the motor current in order to make an instantaneous power supplied from the DC link capacitor to the three-phase motor zero, and also controls the second inverter so that a q-axis component of the second inverter output voltage orthogonal to a d-axis component, which is a magnetic flux direction of the three-phase motor, pulsates in synchronization with the single-phase AC power source.

Motor drive system

An AC-AC converter circuit converts an AC voltage into a further AC voltage. A rectifier circuit rectifies the AC voltage. An inverter circuit generates the further AC voltage. AZ source circuit is provided between the rectifier circuit and the inverter circuit.

AC-AC converter circuit

An AC-AC power convertor converts a first AC voltage to a second AC voltage. A PFC rectifier circuit rectifies an AC voltage (v) so as to generate a rectified voltage. An inverter generates the second AC voltage from the rectified voltage. A controller controls the PFC rectifier circuit and the inverter such that power generated by the first AC voltage and the pulsations of power generated by the rectified voltage are output to an external device.

AC-AC power converter

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Zurich, Switzerland

Michael Haider