异步电机软启动器电压空间矢量控制技术的研究

发布时间：2018-08-08 21:59

【摘要】：在现代工业的发展进程中,随着电力电子技术、微电子技术和控制技术的不断发展。三相交流异步电动机以其结构简单、体积和重量较小、价格低廉、运行可靠等优点已经在许多领域得到了广泛应用,并发挥着重要作用。异步电动机的启动过程会直接影响电网,给其他电力设备带来危害。电动机在启动时的启动电流可以达到额定电流的4~8倍或者更高,过大的启动电流还会影响到并联的其他用电设备,对电网安全运行构成威胁。因此,研究新型的软启动器降低电动机启动时的启动电流、增大启动转矩,减少对电网的影响具有重要的经济价值和社会意义。本课题主要研究如何利用电压空间矢量原理来提高异步电动机的启动性能和启动转矩,并研究设计了基于电压空间矢量软启动器的软硬件控制系统。本论文的主要内容有:(1)分析异步电机软启动器的原理。分析交流异步电动机电磁转矩与定子电压、电源频率之间的关系,并对目前常用的软启动方式逐一分析其工作原理、优缺点等。(2)设计一种以全控型器件IGBT为功率器件的软启动主电路原理结构。详细分析了异步电机的特性,提出采用电压空间矢量的控制方式提高启动转矩。通过控制开关器件的导通时刻实现电压频率的改变,在MATLAB/SIMULINK仿真平台中,建立异步电机电压空间矢量软启动控制模型,对其整个矢量控制系统进行仿真分析,得到仿真结果,验证这种设计的可行性。(3)提出一种十二边形电压空间矢量控制策略的新型软启动器,进行该新型软启动器的系统设计。该新型软启动器采用了十二边形电压空间矢量控制算法,在调节电源电压的同时,也调节了电源的频率,并使电压/频率(U/f)比值相对稳定,保证电机主磁通稳定,在获得较大启动转矩的同时,启动电流又不致过大。可以启动带有一定负载或较大惯性负载的电动机,而电流保持在相对较小的值,从而实现交流电动机小电流、高转矩启动。(4)设计十二边形电压空间矢量软启动器的硬件电路。主要包括主控制芯片STM32电路、通讯电路、电流检测电路、CPLD(Complex Programmable Logic Device)电路、电压检测电路、驱动电路、电源电路等。该设计中CPU(STM32)主要完成算法运算和运行的监控,CPLD主要是结合STM32产生软启动触发脉冲控制信号以及扩展STM32的逻辑功能,使两者的优良性能得到充分发挥。这种方式使CPLD的资源得到了很好的使用,得到了质量较高的控制触发脉冲,进而满足系统的大功率、高可靠性的控制要求。同时该控制系统还可以实现软停车和系统保护等。本文中整体控制系统的实现是在电压空间矢量的方式下完成的,对六边形及十二边形电压空间矢量控制下的软启动器建立了仿真模型进行仿真,并对六边形电压空间矢量控制方案下系统的实物进行性能测试,给出了相应的结果及对比分析,结果显示基于电压空间矢量的新型软启动器带载能力强,具有启动电流小、启动转矩大的优点。文章最后分析了该系统的不足,并提出了改进方案。
[Abstract]:In the process of modern industry development, with the continuous development of power electronics, microelectronic technology and control technology, three phase AC asynchronous motor has been widely used in many fields with its advantages of simple structure, small volume and weight, low price, reliable operation and so on. It plays an important role. Induction motor starts to start. The process will directly affect the power grid and bring harm to other power equipment. The starting current of the motor can reach 4~8 times or higher of the rated current. The excessive starting current also affects the other parallel electrical equipment, which threatens the safe operation of the power grid. Therefore, the new soft starter is studied to reduce the starting of the motor. The starting current, increasing the starting torque and reducing the influence on the power grid are of great economic and social significance. This topic mainly studies how to use the principle of voltage space vector to improve the starting performance and starting torque of asynchronous motor, and research and design a soft and hardware control system based on the voltage space vector soft starter. The main contents of this paper are as follows: (1) analyze the principle of asynchronous motor soft starter, analyze the relationship between electromagnetic torque of AC asynchronous motor and stator voltage and power frequency, and analyze its working principle, advantages and disadvantages one by one. (2) a soft starting power with full control device IGBT as power device is designed. The characteristics of the asynchronous motor are analyzed in detail, and the voltage space vector control mode is proposed to improve the starting torque. By controlling the switching time of the switch device, the voltage frequency is changed. In the MATLAB/SIMULINK simulation platform, the voltage space vector soft start control model of the induction motor is set up, and the whole vector control of the induction motor is set up. The system is simulated and analyzed, and the simulation results are obtained to verify the feasibility of this design. (3) a new type of soft starter with twelve edge voltage space vector control strategy is proposed. The new soft starter is designed for the new soft starter. The new type of soft starter adopts the twelve edge electric voltage space vector control algorithm to adjust the voltage of the power supply. At the same time, the frequency of the power supply is adjusted, and the voltage / frequency (U/f) ratio is relatively stable, and the main flux of the motor is stable. At the same time, the starting current is not too large. The motor can start with a certain load or large inertia load, and the current is kept in a relatively small value, thus the AC motor is realized. Small current, high torque start. (4) design the hardware circuit of the twelve side voltage space vector soft starter. It mainly includes the main control chip STM32 circuit, the communication circuit, the current detection circuit, the CPLD (Complex Programmable Logic Device) circuit, the voltage detection circuit, the driving circuit, the power circuit and so on. The main completion algorithm of CPU (STM32) in this design is the design of the CPU (STM32). The operation and operation monitoring, CPLD mainly combines the STM32 to produce the soft start trigger pulse control signal and the logic function of expanding the STM32, so that the excellent performance of both of the two is fully played. This way makes the resources of the CPLD well used, and gets the high quality control trigger pulse, and then satisfies the high power and high power of the system. The control system can also realize soft parking and system protection. In this paper, the realization of the whole control system is accomplished under the mode of voltage space vector. The simulation model is built for the soft starter under the control of hexagon and twelve sided voltage space vector, and the hexagon voltage space is also simulated. The performance test of the system under the vector control scheme is carried out, and the corresponding results and comparative analysis are given. The results show that the new soft starter based on voltage space vector has the advantages of strong carrying capacity, small starting current and large starting torque. Finally, the shortage of the system is analyzed, and the improvement scheme is put forward.
【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM343

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