Motor Drive Device Phase Current Adjustment for Torque Pulsation
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Solution Overview
Problem
Existing motor drive devices struggle to control drive torque pulsation in independent winding multi-phase motors when a phase becomes open, leading to significant torque pulsation and potential motor shutdown.
Innovation Solution
A motor drive device with an inverter circuit and controller that adjusts the phase difference of currents in normal phases to offset each other's AC powers, using the formula Dp = 360 / (2 * (n - m) when an open phase occurs, where n is the number of phases and m is the number of open phases, ensuring continuous motor operation with reduced torque pulsation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pseudo-square wave current is used to enable continuous drive when a phase is abnormal, then motor drive continuity is improved, but drive torque pulsation increases and cannot be controlled
Solution Approach 1:
The invention changes the control parameters by adjusting the phase difference of currents in normal phases based on the number of open phases. When one phase is open, the phase difference is set to 60 degrees; when two phases are open, it is set to 120 degrees. This parameter adjustment allows the AC powers of normal phases to offset each other, suppressing torque pulsation while maintaining continuous drive operation.
2Power
If independent winding multi-phase motor is used to solve voltage lack without booster circuit, then motor output and capacity are improved, but vulnerability to phase open abnormalities increases
Solution Approach 1:
The invention implements dynamic control by continuously monitoring phase abnormalities and adjusting current phase differences in real-time. The controller dynamically changes the phase difference parameters based on detected open phases, enabling the motor to adapt to abnormal conditions and continue operation without shutdown, thus improving reliability while maintaining high power output capability.
Data Source
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AI summary
The purpose of the present invention is to continue to drive a motor while suppressing drive torque ripple generated by the motor, when any of the phases is opened during the driving of the motor. A motor drive device (200) controls the driving of a motor (100) in which the armature windings (102a, 102b, 102c) of respective phases are independently provided. The motor drive device (200) is equipped with: an inverter circuit (210) for converting the DC power supplied through DC bus lines (201a, 201b) to three-phase AC powers and respectively outputting the three-phase AC powers to the armature windings (102a, 102b, 102c) of the respective phases; and a controller (203) for controlling the inverter circuit (210). When any of the phases is opened in the AC powers output from the inverter circuit (210), the controller (203) adjusts the difference between the phases of the respective currents flowing through the armature windings of normal phases so that the AC powers of the other normal phases except the opened phase are compensated each other.