Open-End Winding Motor Drive Control for Common Mode Current
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Solution Overview
Problem
In motor drive systems using the open-end winding method, the inability to control zero phase component voltages to zero leads to common mode current generation, resulting in efficiency losses and potential burnout damage.
Innovation Solution
A motor drive device is designed to control the zero phase component voltages of two inverters connected to opposite ends of a motor's windings, ensuring they are instantaneously equal, thereby eliminating circulating currents and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the open-end winding method is used with two inverters connected to opposite ends of windings, then the voltage utilization rate is enhanced and high power can be output, but common mode current is generated causing loss and potential burnout damage
Solution Approach 1:
The control device monitors the zero phase component voltages from both inverters and dynamically adjusts the switching signals to maintain their equality, thereby preventing common mode current generation while preserving the high power output capability of the open-end winding configuration
Solution Approach 2:
The invention changes the control parameter by explicitly managing the zero phase component voltages of both inverters, ensuring they remain equal through coordinated switching control, which eliminates the harmful common mode current while maintaining the voltage utilization advantages of the open-end winding method
2Ease of operation
If general DC power is applied to the inverters in the open-end winding method, then the motor can be driven, but the zero phase component voltage cannot be controlled to become zero, resulting in common mode current generation
Solution Approach 1:
The control device continuously monitors the zero phase component voltages and uses feedback control to adjust the inverter switching signals, ensuring that the zero phase component voltages remain equal and their difference is minimized, thereby preventing common mode current and improving system reliability
Solution Approach 2:
The invention applies the equipotentiality principle by controlling the zero phase component voltages of both inverters to be equal, creating an equipotential condition that prevents potential difference-driven common mode current flow through the motor windings
Data Source
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AI summary
A motor drive device is proposed. The motor drive device is configured to drive a motor having a plurality of windings respectively corresponding to a plurality of phases, and includes: a first inverter including a plurality of first switching elements, and connected to a first end of each of the plurality of windings; a second inverter including a plurality of second switching elements, and connected to a second end of each of the plurality of windings; and a controller configured to generate phase voltage commands of the first inverter and phase voltage commands of the second inverter based on preset voltage commands of the motor so that the phase voltage commands of the first inverter and the phase voltage commands of the second inverter are respectively represented as vectors of different angles.