A position sensorless permanent magnet motor direct drive power generation control method

Abstract

A direct-drive power generation control method for a sensorless permanent magnet motor. A full-order observer pole is moved to the left relative to a motor pole to obtain a unified feedback gain matrix, a method of setting estimated rotation speed initial value is adopted to allow the unified feedback gain matrix to adapt to the running of a rotated permanent magnet motor restarted in a sensorlessand the permanent magnet power generation control in the full working conditions. The rotated permanent magnet motor is restarted in the sensorless, the switching of the permanent magnet in the powergeneration process is controlled, and a method of setting the q-axis current reference value of a bus voltage regulator is adopted to suppress the impact current in the switching process. The direct-drive power generation control method can be stably operated in the total speed range, the feedback gain matrix does not need online switching in the restarted rotated permanent magnet motor and permanent magnet motor power generation running, and the switching impact current is small between different work conditions in the full speed range.

Description

technical field [0001] The invention relates to a control method of a permanent magnet motor. Background technique [0002] Permanent magnet motors have high power density, high efficiency, and high control precision, so they are widely used in industry. Usually, the measurement accuracy of the rotor position directly determines the control accuracy of the permanent magnet motor. Generally, the rotor position signal is obtained through a photoelectric encoder or a resolver. However, the use of a position sensor will bring additional electromagnetic interference to the entire system, making the system more complex and less robust. The position sensorless technology has the advantages of high reliability, strong environmental adaptability, weak electromagnetic interference, and high power density. Because the full-order observer has the advantages of high estimation accuracy, strong parameter robustness, and fast dynamic response, it is widely used. . S.Po-ngam scholars pub...

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Problems solved by technology

S.Po-ngam scholars published in IEEETrans.Power Electron about the feedback gain matrix in full-order observers using a fixed damping ratio design method to obtain, such as the document "tability and dynamic performance improvement of adaptive full-order observers for sensorless pmsm drive" , the system tends to oscillate when this kind of feedback gain matrix operates in the high-speed and low-speed regions

In order to solve the problem of the fixed damping ratio design method oscillating in the low-speed area, some scholars have proposed a method of designing the feedback gain matrix by moving the pole of the observer to the left relative to the pole of the motor. This design method can improve the stability and convergence speed of the observer. Improvement, such as the literature "Speed ​​Sensorless Model Predictive Flux Control of Induction Motor Based on Space Vector Modulation", but this method still does not solve the problem of high-speed oscillation

[0003] The initial speed of the motor in the permanent magnet motor power generation system without a position sensor is unknown and not zero. A reliable position sensorless algorithm is urgently needed to estimate the initial speed of the permanent magnet motor rotation, and then switch to normal power generation control , currently in the model predictive control of asynchronous motors, H.Yang published a position sensorless algorithm for asynchronous motors that start rotating on IEEE Trans.Energy Convers, such as the document "Amethod to start rotating induction motor based on speed sensorless model-predictive control", However, this method needs to switch the feedback gain matrix online, and at the same time, the literature uses the objective function to suppress the problem of excessive inrush current in the restart and electric control switching

For the permanent magnet motor direct drive power generation vector control, there is currently no better method that can simultaneously satisfy: 1) the system is stable and reliable in the full speed range, with high estimation accuracy and strong parameter robustness; Rotating permanent magnet motor; 3) The feedback gain matrix does not need to be switched online; 4) The inrush current of the rotating permanent magnet motor and the permanent magnet motor generating control operation without a position sensor is small

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