SR Motor Regenerative Timing Control via Current Feedback
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Solution Overview
Problem
The challenge in SR motor regenerative operation is determining the exact end timing of the regenerative mode, leading to inefficient synchronous rectification control due to potential backward current flow, which affects power generation efficiency.
Innovation Solution
A control system that uses a map set with parameters such as advance angle, energization angle, and rotation speed to determine the end timing of the regenerative mode, enabling clear synchronization and optimal timing for synchronous rectification control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If synchronous rectification control is performed using conventional timing methods, then the control system is simple, but the end timing of regenerative mode cannot be determined exactly causing backward current flow and reduced power generation efficiency
Solution Approach 1:
The patent implements feedback control by detecting the actual current waveform during regenerative operation and using this information to determine the precise end timing of the regenerative mode. The controller monitors the current through the FETs and uses this feedback to synchronize the turn-off timing, eliminating backward current flow while maintaining control simplicity.
Solution Approach 2:
The patent replaces conventional mechanical or fixed-timing control methods with electronic sensing and control. By using electronic current detection and programmable timing based on detected waveforms, the system achieves precise end timing determination without complex mechanical structures or additional hardware components.
2Loss of energy
If the regenerative mode end timing is extended to prevent backward current, then power generation efficiency improves, but the control timing becomes less precise causing delayed rectification
Solution Approach 1:
The system continuously monitors the current waveform during regenerative operation and uses this real-time feedback to determine the exact moment when regenerative mode should end. This feedback mechanism allows precise timing determination that adapts to actual operating conditions, preventing both premature and delayed termination.
Solution Approach 2:
The patent implements dynamic timing adjustment where the end timing of regenerative mode is not fixed but adapts based on detected current characteristics. The controller dynamically determines the optimal end timing point by analyzing the actual current waveform, allowing precise synchronization that responds to changing operational conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves power generation output and efficiency by ensuring precise timing for the end of the regenerative mode, preventing backward current flow and enhancing overall regenerative operation.
Implementation Method 1
The excitation coils are selectively energized to sequentially excite the inward salient poles of the stator to allow the inward salient poles of the stator to magnetically attract the outward salient poles of the rotor to thereby generate a rotational torque in the rotor
Implementation Method 2
the inward salient poles of the stator to magnetically attract the outward salient poles of the rotor
Implementation Method 3
when the rotor is rotated by external force, the generated magnetic flux is reduced by the rotation, with the result that electromotive force is generated in the excitation coils so as to maintain the magnetic flux. As a result, a regenerative current is generated in the excitation coils
Data Source
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AI summary
An SR motor control system 10 includes: an SR motor 1, a driver circuit 2 having FETs 31 to 34 for adjusting an energization timing to an excitation coil 4 of the SR motor 1, and an energization control part 3 that controls ON/OFF of the FETs 31 to 34. The SR motor 1 has a supply mode in which the excitation coil 4 is energized and a regenerative mode in which electromotive force generated in the excitation coil 4 is recovered. The energization control part 3 has a synchronous rectification part 21 that determines an end time of the regenerative mode based on a current value of the excitation coil 4 during the regenerative mode.