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US 2010/0079093 A1Published application
Electric power converter
AssigneeMitsubishi Electric Corporation
InventorHidetoshi Kitanaka
Life of this patent
Estimating the term…
Abstract
Specific anomalies and details of failures as well as measures thereagainst are described that might possibly occur in electric power converters that drive and control permanent-magnet synchronous motors. An electric power converter capable of stable operation has a protective function of taking proper measures against such failures that might possibly occur.
Claims5
An electric power converter comprising:
- a converter having switching elements, for converting AC power from an AC power supply into DC power;
- a capacitor connected in parallel to a DC side of said converter;
- an inverter having switching elements and being connected in parallel with said capacitor, for driving and controlling a permanent-magnet synchronous motor;
- a discharge circuit connected in parallel with said capacitor;
- a supply-side switch interposed between the AC power supply and an AC side of said converter;
- a motor-side switch interposed between said inverter and the permanent-magnet synchronous motor;
- a supply-voltage sensor for measuring voltage of the AC power supply;
- a capacitor-voltage sensor for measuring voltage across said capacitor;
- an input-current sensor for measuring AC current to said converter;
- an output-current sensor for measuring AC current from said inverter;
- and
- a system controller for controlling said supply-side switch, said converter, said discharge circuit, said inverter, and said motor-side switch by receiving input signals from said supply-voltage sensor, said capacitor-voltage sensor, said input-current sensor, and said output-current sensor, wherein
- said system controller, when a voltage measured by said capacitor-voltage sensor becomes equal to or lower than a first predetermined value, turns off all switching elements of said converter and all switching elements of said inverter;
- when the voltage measured by said capacitor-voltage sensor becomes equal to or lower than a second predetermined value that is smaller than the first predetermined value, turns off said supply-side switch;
- and
- when the voltage measured by said capacitor-voltage sensor becomes higher than the second predetermined value, does not turn off said supply-side switch.
13 more elements
2-35. (canceled)
An electric power converter comprising:
- a converter having switching elements, for converting AC power from an AC power supply into DC power;
- a capacitor connected in parallel to a DC side of said converter;
- an inverter having switching elements and being connected in parallel with said capacitor, for driving and controlling a permanent-magnet synchronous motor;
- a discharge circuit connected in parallel with said capacitor;
- a supply-side switch interposed between the AC power supply and an AC side of said converter;
- a motor-side switch interposed between said inverter and the permanent-magnet synchronous motor;
- a supply-voltage sensor for measuring voltage of the AC power supply;
- a capacitor-voltage sensor for measuring voltage across said capacitor;
- an input-current sensor for measuring AC current to said converter;
- an output-current sensor for measuring AC current from said inverter;
- and
- a system controller for controlling said supply-side switch, said converter, said discharge circuit, said inverter, and said motor-side switch by receiving input signals from said supply-voltage sensor, said capacitor-voltage sensor, said input-current sensor, and said output-current sensor, wherein
- said system controller, when a voltage measured by said capacitor-voltage sensor becomes equal to or lower than a first predetermined value, turns off all switching elements of said converter and all switching elements of said inverter;
- when the voltage measured by said capacitor-voltage sensor becomes equal to or lower than a second predetermined value that is smaller than the first predetermined value, turns off said motor-side switch;
- and
- when the voltage measured by said capacitor-voltage sensor becomes higher than the second predetermined value, does not turn off said motor-side switch.
13 more elements
Dependencies are inferred from the claim text.