Permanent Magnet Synchronous Motor Hall Sensor Position Estimation And Fault Tolerance Control

With environmental pollution becoming a much more significant concern,the market for low-speed electric vehicles has expanded fast.Since that time,permanent magnet synchronous motors and space vector control technique have seen widespread use.Getting precise information about the current value and the rotor position is the foundation of vector control,especially rotor position information.Position sensors such as encoders and rotary transformers can obtain high-precision position information,but they are not suitable for low-speed electric vehicles due to their high price and poor stability.Hall sensor is a common position sensor for low-speed electric vehicles due to its low price and suitable for various complex environments.However,the resolution of Hall sensor is low,at the same time in the operation process is also inevitable failure,there are security risks.Low resolution Hall sensors are essential for fault tolerant control,position estimation,and fault detection.Firstly,this work introduces the current state of position estimation research and fault-tolerant control based on the Hall sensor,along with many methods for position estimation and position sensorless control under Hall sensor defect.At the same time,along with providing the vector control and space vector pulse width modulation technologies,this section also provides a mathematical model of permanent network synchronization that is analogous to these technologies.Secondly,the impacts of the average velocity technique and the acceleration position estimate method on rotor position estimation are compared and analyzed.In view of the position estimation error,two correction methods,fast correction and slow correction,are used to analyze the error correction.To identify the defect signal,when the hall sensor has a single failure,the direction sensitive diagnosis technique is used,and the hall position estimate algorithm is enhanced.In case of double fault or full fault of Hall sensor,non-inductive control is selected.Simulation verification and analysis are carried out.Thirdly,in the position sensorless control,the rotor position estimation at low speed is not accurate due to the inaccurate resistance parameters of the sliding mode observer and the nonlinearity of the inverter.The introduction of the resistance adaptive sliding mode observer identifies the resistance in real time to enhance the parameter robustness of sliding mode observation.The possibility of erroneous compensation caused by incorrectly judging current polarity is avoided at the same time by proposing an improved linear dead zone compensation approach.The sliding mode observer’s load capacity and location estimate accuracy are considerably enhanced at low speeds.Finally,an experimental test platform based on Hall sensor position estimation and a fault-tolerant permanent magnet synchronous motor control system were created.To confirm the accuracy of Hall position estimate and the dependability of fault-tolerant control described in this research,relevant experimental tests were carried out when designing a fault-tolerant program and Hall position estimation.