Rotary Machine Control Device Phase Difference Noise Torque
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Solution Overview
Problem
Existing rotary machine control devices with multi-group multiphase winding configurations face challenges in reducing electromagnetic noise while maintaining maximum torque, particularly when the number of poles and slots are set to combinations that prevent a 180° electric phase difference between winding groups, and previous solutions fail to effectively reduce noise without compromising torque output.
Innovation Solution
A rotary machine control device with a power converter and control unit that sets a phase difference of 150° ≤ θcoil < 180° or 180° < θcoil ≤ 210° between odd-number and even-number winding groups, and switches the voltage command phase difference between 180° and θcoil to manage electromagnetic noise and torque output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a 180° phase difference is applied between voltage commands for respective groups, then electromagnetic noise is reduced, but torque output is compromised when the number of poles and slots prevent a 180° electric phase difference
Solution Approach 1:
The patent dynamically adjusts the phase difference between voltage commands for different winding groups based on operating conditions. The control unit switches between a first phase difference (optimized for noise reduction) and a second phase difference (optimized for torque output) according to the required output level, making the system adaptable rather than fixed.
Solution Approach 2:
The patent changes the electrical parameter (phase difference angle) between voltage commands applied to different winding groups. By varying this parameter between a first value (e.g., 180° for noise reduction) and a second value (different from first for torque optimization), the system can optimize performance for different operating conditions without hardware modifications.
2Object-affected harmful factors
If noise filter is added to reduce electromagnetic noise, then electromagnetic noise is suppressed, but device space and cost increase
Solution Approach 1:
The patent converts the harmful electromagnetic noise generated by switching operations into a beneficial effect by strategically applying phase differences between voltage commands. The switching operations that normally create noise are orchestrated to produce phase differences that cause noise cancellation between different winding groups, eliminating the need for external noise filters.
Solution Approach 2:
The control system uses its own switching operations to generate phase differences that suppress electromagnetic noise. Instead of requiring separate noise filtering components, the system's inherent switching mechanism is utilized to create self-cancelling noise patterns through coordinated control of multiple winding groups.
3Object-affected harmful factors
If carrier waves are reversed to reduce electromagnetic noise, then electromagnetic noise is reduced, but adaptability to different pole-slot combinations is limited
Solution Approach 1:
The patent changes the phase difference parameter between voltage commands applied to different winding groups. By adjusting this electrical parameter rather than relying on fixed carrier wave reversal, the system can adapt to various pole-slot combinations while maintaining noise suppression effectiveness.
Data Source
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AI summary
In a rotary machine control device (1) for controlling a rotary machine (2) having a multi-group multiphase configuration, a phase difference θcoil of 150° to 210° (excluding 180°) is electrically provided between a winding for an odd-number group and a winding for an even-number group in the rotary machine (2), wherein, when the effective value of a voltage command is smaller than a voltage threshold, the phase difference between the voltage commands for the respective groups is set to 180°, and when a torque command is greater than a torque threshold, the phase difference between the voltage commands for the respective groups is set to θcoil.