MOTOR CONTROL APPARATUS EQUIPPED WITH PROTECTION OPERATION COMMAND UNIT
First Claim
1. A motor control apparatus comprising:
- a rectifier configured to rectify AC power supplied from a three-phase AC input side to output DC power;
an inverter connected to a DC link on a DC output side of the rectifier and configured to convert power between DC power of the DC link and AC power as drive power or regenerative power of a motor;
an AC voltage detection unit configured to detect an AC voltage value on the three-phase AC input side of the rectifier;
a voltage amplitude calculation unit configured to calculate a power source voltage amplitude value from the AC voltage value;
a power failure recovery detection unit configured to determine that the three-phase AC input side of the rectifier has transitioned from the power recovery state to a power failure state when the power source voltage amplitude value becomes a value less than or equal to a power failure detection reference voltage value from a value greater than the power failure detection reference voltage value in a power recovery state, and to determine that the three-phase AC input side of the rectifier has transitioned from the power failure state to the power recovery state when the power source voltage amplitude value becomes a value greater than or equal to a power recovery detection reference voltage from a value less than the power recovery detection reference voltage value in the power failure state;
a protection operation command unit configured to output a protection operation command to the inverter to output power for the motor to perform a predetermined protection operation when a protection operation reference time has elapsed from a time point at which the power failure recovery detection unit determined that the three-phase AC input side of the rectifier had transitioned from the power recovery state to the power failure state;
a time measurement unit configured to measure an elapsed time from a time point at which the power failure recovery detection unit determines that the three-phase AC input side of the rectifier has transitioned from the power failure state to the power recovery state; and
a condition change unit configured to change at least one of the power failure detection reference voltage value and the protection operation reference time in response to the elapsed time.
1 Assignment
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Accused Products
Abstract
A motor control apparatus includes a rectifier which converts AC of a power source to DC, an inverter which converts DC to AC for a motor, a voltage amplitude calculation unit which calculates a power source voltage amplitude value, a power failure recovery detection unit which determines whether or not the AC input side has transitioned to a power failure state or a power recovery state on the basis of the power source voltage amplitude value, a protection operation command unit which outputs a protection operation command when a reference time has elapsed from a time point at which the AC input side transitioned to the power failure state, a time measurement unit which measures an elapsed time from when the AC input side transitioned to the power recovery state, and a condition change unit which changes the power failure reference voltage value and/or the reference time.
16 Citations
3 Claims
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1. A motor control apparatus comprising:
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a rectifier configured to rectify AC power supplied from a three-phase AC input side to output DC power; an inverter connected to a DC link on a DC output side of the rectifier and configured to convert power between DC power of the DC link and AC power as drive power or regenerative power of a motor; an AC voltage detection unit configured to detect an AC voltage value on the three-phase AC input side of the rectifier; a voltage amplitude calculation unit configured to calculate a power source voltage amplitude value from the AC voltage value; a power failure recovery detection unit configured to determine that the three-phase AC input side of the rectifier has transitioned from the power recovery state to a power failure state when the power source voltage amplitude value becomes a value less than or equal to a power failure detection reference voltage value from a value greater than the power failure detection reference voltage value in a power recovery state, and to determine that the three-phase AC input side of the rectifier has transitioned from the power failure state to the power recovery state when the power source voltage amplitude value becomes a value greater than or equal to a power recovery detection reference voltage from a value less than the power recovery detection reference voltage value in the power failure state; a protection operation command unit configured to output a protection operation command to the inverter to output power for the motor to perform a predetermined protection operation when a protection operation reference time has elapsed from a time point at which the power failure recovery detection unit determined that the three-phase AC input side of the rectifier had transitioned from the power recovery state to the power failure state; a time measurement unit configured to measure an elapsed time from a time point at which the power failure recovery detection unit determines that the three-phase AC input side of the rectifier has transitioned from the power failure state to the power recovery state; and a condition change unit configured to change at least one of the power failure detection reference voltage value and the protection operation reference time in response to the elapsed time. - View Dependent Claims (2, 3)
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Specification