Fault-tolerant control method for position sensor of switched reluctance motor
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Solution Overview
Problem
Conventional fault-tolerant control methods for position sensors in switched reluctance motors fail to account for variable speed or acceleration conditions, leading to significant deviations in reconstructed output signals and impaired fault-tolerant control effects.
Innovation Solution
A method that calculates and reconstructs the next edge pulse based on specific time intervals (T1, T2, T3, T4) between consecutive edge pulses when a failure occurs, ensuring accurate and reliable fault-tolerant operation by interpolating the next edge pulse at the calculated time interval T4 after the current edge pulse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fault-tolerant control methods are used to reconstruct position sensor output signals, then the system can operate with a failed sensor, but the reconstructed signals have large deviation under variable speed or acceleration conditions
Solution Approach 1:
The patent applies dynamics by making the reconstruction method adaptive to varying operating conditions. The system dynamically adjusts the reconstruction approach based on real-time detection of speed and acceleration states, using different calculation formulas for T4 under constant speed, constant acceleration, and variable acceleration conditions. This dynamic adaptation eliminates the large deviations that occur with fixed conventional methods, thereby resolving the contradiction between maintaining fault-tolerant operation and ensuring measurement precision across varying operational states.
Solution Approach 2:
The patent changes the parameters used for signal reconstruction based on operating conditions. By detecting whether the motor is in constant speed, constant acceleration, or variable acceleration state, the system selects appropriate formulas to calculate the time interval T4. This parameter change strategy ensures that the reconstructed position signals maintain high accuracy under different operating conditions, resolving the contradiction between fault-tolerant capability and signal precision.
2Measurement precision
If the reconstruction algorithm accounts for variable speed and acceleration conditions, then the reconstructed signal accuracy improves, but the algorithm complexity increases
Solution Approach 1:
The patent segments the operating conditions into distinct categories: constant speed, constant acceleration, and variable acceleration. For each segment, a specific reconstruction formula is applied. This segmentation approach maintains algorithm simplicity while improving accuracy, as each segment has a dedicated straightforward formula rather than requiring a single complex universal algorithm. The segmentation resolves the contradiction by organizing complexity into manageable, condition-specific segments.
Solution Approach 2:
The patent performs preliminary detection of the operating condition (constant speed, constant acceleration, or variable acceleration) before executing the reconstruction. By preliminarily identifying the current operational state, the system can select the appropriate formula in advance, avoiding the need for complex real-time calculations during reconstruction. This preliminary action simplifies the overall algorithm structure while maintaining high reconstruction accuracy under varying conditions.
Data Source
AI summary
A fault-tolerant control method for a position sensor of a switched reluctance motor, if the position sensor of the switched reluctance motor runs without a fault, detecting, in real time, four equal-interval or equal-angle continuous edge pulses of an output signal of the position sensor, the fourth edge pulse being the current edge pulse, and detecting time intervals (T1, T2, T3) between each two adjacent edge pulses sequentially, thereby calculating a time interval (T4) between the current edge pulse and a next edge pulse following the current edge pulse. If the position sensor of the switched reluctance motor fails, and the next edge pulse following the current edge pulse is lost, reconstructing the next edge pulse after the interval time (T4) of the current edge pulse of the output signal of the position sensor. The method can be used, when one or more position sensors of a rotatory and linear switched reluctance motor having various phases and various topology structures fail, to reconstruct an edge pulse after lost.