Inverter apparatus for polyphase AC motor drive
AssigneeMitsubishi Electric Corporation
InventorsYu Kawano, Takahiro Okanoue
Life of this patent
Estimating the term…
Abstract
In view of the problem that an existing technique can detect a failure in an arm circuit for each phase and continue motor drive by only a normal phase, but a brake torque is generated due to a closed circuit of the faulty phase, an inverter apparatus for polyphase AC motor drive is provided that includes: a first power supply switching device in a power supply line to an inverter circuit; a second power supply switching device for each phase in the arm circuit of the inverter circuit, and a motor relay switching device in an output path from each phase, wherein the parasitic diodes of the first power supply switching device and second power supply switching device have directional characteristics different from each other, which prevent generation of a closed circuit.
Claims15
An inverter apparatus for polyphase AC motor drive comprising:
- an inverter circuit connected between a power source and a polyphase AC motor for converting power from the power source to polyphase AC power to be supplied to the polyphase AC motor;
- a first power supply switching device provided between the power source and the inverter circuit for opening/closing the electric path between the power source and the inverter circuit;
- a motor relay switching device provided between an output point of the inverter circuit for each phase and the polyphase AC motor for opening/closing the electric path between the output point and the polyphase AC motor;
- a second power supply switching device provided downstream of the first power supply switching device with respect to the power source for each phase of the inverter circuit;
- and a control circuit for performing switching control of the first power supply switching device, the second power supply switching device, the motor relay switching device and the inverter circuit, wherein a first diode is provided, connected in parallel with the first power supply switching device and in the forward direction with respect to the current supply direction, and a second diode is provided, connected in parallel with the second power supply switching device and in the reverse direction with respect to the current supply direction.
Dependencies are inferred from the claim text.