| 英文摘要 | Alternating-current(AC) servo system is a kind of electric drive system used for angular position or rotating speed control, which has broad applications in CNC, vehicle traction, aerospace, etc. Permanent magnet synchronous motor (PMSM) is playing a more and more significant role in small-medium power drive occasions for its superior characteristics, which include high precision, small inertia, high power density, etc. The control of PMSM has been widely researched by researchers and engineers, however, there are still many theoretical and technical problems to solve. In order to improve the performance of AC servo system, the key technologies of PMSM servo controller, which include field oriented control, current measurement and calibrating, robust control of current, speed detection method, speed control strategy, position servo, etc., were studied deeply in this dissertation. The main contributions of this thesis include following issues: ①This thesis summarized the development of PMSM AC servo system. The mathematical model of PMSM was presented, and various field oriented control strategies were analyzed in detail. I studied active disturbance rejection control technology (ADRC), and made a try to apply ADRC in PMSM controller. ②This thesis investigated the source of AC noise contained in measured d/q current signals, and came to the conclusion that same-frequency noise is induced by the middle value inaccuracy of current measurement circuit. To solve this problem, an online calibrating algorithm based on finite state machine is proposed, which can tightly track the middle value of current measurement circuit, and correct the corresponding parameters used in current sampling and calculating algorithm in time. Experimental results verify the feasibility and effectiveness of the proposed method. ③Robustness of PI parameters of current regulator tuned under locked-rotor condition may be degraded when rotor speed is not zero. To solve this problem, this thesis analyzed the impact of rotor speed on d/q current, and proposed a voltage feed forward current control method. Simulation results show that, voltage feed forward current control method is able to suppress the impact of rotor speed on current regulator, so that current control performance can be improved. ④To solve the problem that M/T speed detection method used in AC servo systems with an incremental optical encoder was susceptible to mechanical vibration, this thesis analyzed the imp... |
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