基于双闭环复合控制的软起动谐波抑制的应用研究

发布时间：2018-05-01 07:34

本文选题：晶闸管软起动器 + 自适应谐波检测　；参考：《兰州交通大学》2015年硕士论文

【摘要】：晶闸管软起动器依靠无极平稳的起动特性,可有效减小鼠笼式三相异步电机起动过程中产生的电流冲击,得到国内外越来越广泛的重视。但是晶闸管软起动器作为电力电子技术的一个应用产品,其工作过程中会消耗大量无功功率,产生高次谐波信号。谐波会对电力设备、供电安全造成严重危害。针对安装晶闸管软起动器的某空压机起动过程所产生的谐波,采用并联型的有源电力滤波器,动态抑制谐波、补偿无功电流。论文对所采用的自适应谐波检测法和双闭环复合控制法,做了较深入的探讨。主要研究内容为以下几个方面:(1)对空压机的三相异步电机进行等效建模、起动特性的分析,并对晶闸管三相交流调压电路和谐波问题作了分析。通过直接起动与限流软起动的仿真对比得到,直接起动方式的起动电流是额定电流的数倍,严重影响电机寿命,而软起动方式起动平缓,可按设定要求改变起动特性。但同时,也发现晶闸管起动器工作过程中发生负载侧电流畸变现象。(2)有源电力滤波器的谐波电流检测采用自适应谐波检测法。对传统定步长LMS(Least Mean Square,最小均方)算法和后继改进的自适应变步长LMS算法分析研究后,提出一种将动态因子、动量因子统一化,且两者均按箕舌线函数最简式变化的自适应变步长LMS算法。通过仿真对比分析,表明改进算法具有良好的检测特性。(3)有源电力滤波器的跟踪控制方法为双闭环复合控制,内外闭环依据各波形特点采用不同的控制策略。外环电压环,采用模糊PI控制方法以保证直流侧电容电压的稳定性。内环电流环,设计单神经元PI控制与重复控制结合的控制策略,跟踪补偿呈周期性重复变化的谐波电流信号。通过仿真对比,表明内外环的搭配控制方式合理,效果良好。通过理论分析和仿真研究可以有效证明:对于晶闸管软起动器的三相交流调压电路所产生的谐波电流,采用文中给出的自适应谐波检测法和双闭环复合控制的并联有源电力滤波器,可以明显抑制谐波电流,提高了有源电力滤波器用于晶闸管软起动所产生谐波电流的应用效果。
[Abstract]:The soft starter of the thyristor soft starter can effectively reduce the current impact in the starting process of the mouse cage three-phase asynchronous motor, and get more and more attention at home and abroad. However, as an application product of power electronics, the thyristor soft starter will consume a lot of reactive power and produce a lot of reactive power. High order harmonic signals. Harmonics will cause serious harm to power equipment and power supply safety. In this paper, a parallel type of active power filter is used to suppress harmonics and compensate reactive current. Adaptive harmonic detection method and double closed loop compound control are used in this paper. The main research contents are as follows: (1) the equivalent modeling of the three-phase asynchronous motor of the air compressor, the analysis of the starting characteristics and the analysis of the problem of the harmonic wave of the thyristor three-phase AC voltage regulation circuit are analyzed. The direct starting method is obtained by the comparison of the direct starting with the limiter soft starting. The dynamic current is several times of the rated current, which seriously affects the life of the motor, while the soft starting mode is slow to start, and the starting characteristics can be changed according to the set requirements. But at the same time, the current distortion of the load side occurs during the operation of the thyristor starter. (2) the harmonic current detection method of the active power filter adopts the adaptive harmonic detection method. After the analysis of fixed step length LMS (Least Mean Square, minimum mean square) algorithm and stepwise adaptive variable step length LMS algorithm, an adaptive variable step length LMS algorithm, which integrates dynamic factors and momentum factors, and both are based on the most simple change of the skip line function, shows that the improved algorithm has good detection. (3) the tracking control method of active power filter is double closed loop control, and the internal and external closed loop adopts different control strategies according to the characteristics of each waveform. Outer loop voltage loop, fuzzy PI control method to ensure the stability of capacitance voltage of the DC side. Internal loop current loop, control of single neuron PI control and repetitive control Through the simulation and comparison, it is proved that the harmonic current produced by the three-phase AC voltage regulation circuit of the thyristor soft starter can be effectively proved by the theoretical analysis and simulation research. The harmonic current and the harmonic current of the active power filter used in the soft start of the thyristor can be improved. The harmonic detection method and the parallel active power filter with double closed loop control can obviously restrain the harmonic current.

【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM761;TN713.8

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