六脉波双变量交—交连续变频调速系统闭环控制策略研究

发布时间：2018-03-02 22:16

本文选题：双变量　切入点：交交变频　出处：《河南理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文在传统的双变量交交变频有级变频的基础上,进一步研究六脉波交交变频连续变频控制策略以及闭环控制在调速系统中的应用。在原有的六脉波双变量交交变频调速系统中,频率调节都是根据余弦交截法,事先离线计算出在某个特定的频率下晶闸管的触发顺序和触发时刻,编写成触发表,根据触发表来进行有级变频,运用查表法进行变频,不仅离线计算繁琐、计算量大,而且只能在有触发表的几个频率下进行变频切换,并且频率切换时较大的频率级差会导致系统的震荡和冲击。因此,本文提出了连续变频的控制策略。并在连续变频的基础上,加入速度闭环,通过频率调节来实现闭环调速。首先,根据交交变频的基本原理,提出了在统计意义下的连续变频控制策略的概念。根据余弦交截法的计算规律,将离线计算触发表的方法改为在线实时计算触发时刻,并分析了负荷特性以及触发后沿的计算方法,为连续变频策略提供了理论基础。其次,基于在线实时计算触发时刻的方法,通过Matlab仿真和实验,分别验证了的整数分频下和任意给定频率的电压、电流、转速波形,并且给出了连续变频策略下的仿真和实验调速波形,调速效果较好、过渡过程平稳。最后,在连续变频的基础上,在双变量交交变频调速系统中引入了闭环控制。通过Matlab/Simulink下建立闭环仿真控制模型,研究在速度给定突变和负载突变两种情况下的闭环控制效果。通过实验验证,表明了在交交变频调速系统中,连续变频策略下的闭环控制具有良好的动态和稳态效果。
[Abstract]:In this paper, based on the traditional two-variable AC-AC frequency conversion, This paper further studies the control strategy of six pulse wave AC / AC continuous frequency conversion and the application of closed loop control in the speed regulation system. In the original six pulse wave dual variable AC / AC frequency control system, the frequency regulation is based on the cosine intersection method. The trigger order and trigger time of thyristor at a certain frequency are calculated in advance, and the trigger table is compiled. According to the trigger table, the frequency conversion is carried out step by step. The method of look-up table is used for frequency conversion. The off-line calculation is not only complicated, but also the calculation is heavy. Moreover, frequency conversion can only be performed at several frequencies with a trigger meter, and the large frequency level difference in frequency switching will lead to the oscillation and impact of the system. Therefore, a control strategy of continuous frequency conversion is proposed in this paper, and on the basis of continuous frequency conversion, The speed closed-loop is added to realize the closed-loop speed regulation by frequency regulation. Firstly, according to the basic principle of AC-AC frequency conversion, the concept of continuous frequency conversion control strategy in the statistical sense is put forward. The method of off-line calculation of trigger table is changed to on-line real-time calculation of trigger time, and the calculation method of load characteristics and trigger back edge is analyzed, which provides a theoretical basis for continuous frequency conversion strategy. Based on the on-line real-time calculation of trigger time, the waveform of voltage, current and rotational speed of integer frequency division and any given frequency are verified by Matlab simulation and experiment, respectively. And the simulation and experiment speed control waveform under the strategy of continuous frequency conversion are given. The speed regulation effect is better and the transition process is stable. Finally, on the basis of continuous frequency conversion, The closed-loop control is introduced into the two-variable AC / AC variable frequency control system. The closed-loop simulation control model is established under Matlab/Simulink, and the closed-loop control effect is studied under the condition of the given speed mutation and the load mutation. It is shown that the closed-loop control under the continuous frequency conversion strategy has good dynamic and steady effect in the AC / AC variable frequency speed control system.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM921.51

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