The AC-servo System Of Permanent Magnet Synchronous Motor: Design And Implementations

Micro-electronics,power electronic, computer technology, permanent magnetic materials and advanced control theory are developing with the industrial modernization. So AC motor control technology also has got quick development.In such circumstances, so the application and control technology of AC servo system has been rapid development. PMSM is widely used in AC servo system for its high power density, small size, low inertia, low loss and high efficiency nowadays. So it has Huge market demand that the application of PMSM AC servo system is extensive in the small power occasion. Such as fixed speed drive, speed drives and high-precision control, involving almost every area of industrial control. However, the mature drivers in market still use PI algorithm which is heavily hindered its development. In this paper, the purpose is focused on the design of high-precision servo algorithm and prototype. The main works of this thesis are as follows:Firstly, the use of space salient due to the inherent salient of a motor and saturation effect, through the stator into high frequency pulsating voltage to estimate the initial rotor position. By analyzing high-frequency current response, we find that: the fundamental component of q-axis current includes the information of rotor position but there are multiple solutions, the second harmonic component of d-axis current contains the polarity information which can filter out the invalid solution. According to the both information, we can estimate the initial rotor position, paving the way for the vector control well.Secondly, the paper proposed an anti-windup control law by two-step method based on vector control. The first step is to design the basic control law using backstepping method according to the mathematical model. And the Lyapunov function guarantees the stability of the system. Then amplitude and rate constraints are introduced through command filter. When situation happens, the ? filter is working to handle the saturation of the system under control law to reconstruct. In the other hand, command filter can also reduce the calculation expansion which caused by the virtual control law differential operation. Finally, we prove the stability of the closed-loop system with command filter is proved using Tikhonov Lemma.Thirdly, the hardware circuit is designed according the principle of the servo drives, which can be divided into two parts: control board and drive board. Control board uses TMS320F2812 as core chips. Its EV, ADC, SCI module are using to implement control and communication. The drive part's core chip is provided FareChild-Semi, named FSBB20CH60C. The IPM chip coupled with the corresponding circuit, filter circuit, buffer circuit, the brake circuit, the isolation circuit and power management circuitry forms the whole drive circuit. Then a Host computer interface is designed by using MATLAB GUI. At last the total control flow is proposed according to SVPWM. The paper laid the foundation for the future research.