Maglev Rotor Displacement Sensing Circuit for Coplanar Control
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Solution Overview
Problem
Existing displacement sensors for maglev rotor systems require a separate detection surface, increasing the axial size of the rotor and leading to non-coplanar detection and control, resulting in errors and high costs.
Innovation Solution
A displacement detection circuit comprising a current sampling circuit, Hall sensors arranged in auxiliary air gaps, and a Hall signal processing circuit that performs differential processing to determine the rotor's displacement, allowing for coplanar detection and control without additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional displacement sensor is used to detect rotor displacement, then the displacement can be measured, but the axial size of the rotor increases and the detection surface must be selected separately
Solution Approach 1:
The patent combines the displacement detection function with the existing magnetic bearing structure by integrating Hall sensors into the auxiliary air gaps. The detection function is merged with the support function, eliminating the need for separate detection surfaces and reducing axial size while maintaining measurement precision.
Solution Approach 2:
The auxiliary air gaps in the magnetic bearing structure serve dual purposes: providing magnetic support and enabling displacement detection. By placing Hall sensors in these auxiliary air gaps, the same structural elements perform both support and sensing functions, avoiding additional axial space requirements.
2Measurement precision
If a traditional displacement sensor with separate detection surface is used, then displacement detection is possible, but the detection and control become non-coplanar resulting in errors
Solution Approach 1:
The detection and control functions are merged into the same coplanar structure by placing Hall sensors in the auxiliary air gaps that are aligned with the magnetic bearing's control plane. This ensures that displacement detection and control operations occur in the same plane, eliminating alignment errors.
3Measurement precision
If a traditional displacement self-sensing method extracting current ripple components is used, then rotor position can be estimated, but a complex extracting circuit is required to ensure estimation precision
Solution Approach 1:
The patent replaces the complex signal processing method (extracting current ripple components) with a direct physical measurement approach using Hall sensors. This substitution eliminates the need for complex extracting circuits while providing direct, precise displacement measurements through magnetic field sensing.
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 solution reduces the axial size of the rotor, achieves high precision, and simplifies the design, enabling high-precision control of the maglev system while eliminating errors associated with traditional methods.
Implementation Method 1
Hall sensors, wherein the Hall sensors are arranged in an upper auxiliary air gap, and a lower auxiliary air gap of the maglev rotor system, and sensing surfaces of the Hall sensors are perpendicular to magnetic field directions in the corresponding auxiliary air gaps
Data Source
AI summary
The present disclosure provides a displacement detection circuit of a maglev rotor system and a displacement self-sensing system thereof. The displacement detection circuit comprises a current sampling circuit (10) configured to collect a current flowing through a corresponding coil (4); coils (4), which are coils (4) distributed in series in the maglev rotor system; Hall sensors (20), the Hall sensors (20) being arranged in an upper auxiliary air gap (8) and a lower auxiliary air gap (8) of the maglev rotor system, and sensing surfaces of the Hall sensors (20) being perpendicular to magnetic field directions in the corresponding auxiliary air gaps (8); a Hall signal processing circuit (30) connected to the Hall sensors (20) and configured to differentiate a Hall sensing signal corresponding to the upper auxiliary air gap (8) and a Hall sensing signal corresponding to the lower auxiliary air gap (8); and a displacement signal resolving circuit (40) connected to the current sampling circuit (10) and the Hall signal processing circuit (30) respectively and configured to acquire a displacement of a rotor in the maglev rotor system according to the current and a differentiation result. By using the detection circuit and the displacement self-sensing system thereof, the axial size of the rotor is reduced, such that detection and control are coplanar, and high precision and simple design are realized.