基于PLC的无源滤波器研究

基于PLC的无源滤波器研究(任务书,开题报告,论文说明书17000字)
摘  要
随着电力的普及以及不断地应用，电能已经成为了目前最主要的使用能源，而随着电能使用率的不断提高，一些问题也随之凸显了出来，比如电网中电力电子设备以及大容量的非线性负载的不断增多，电网中的谐波问题也越发的复杂与严重，谐波属于一种能量污染，如果放任不管，会造成很大的危害，比如会损坏设备，造成系统的误判等等，所以谐波的治理也越发的重要起来。本次研究的主要内容便是设计一个基于PLC控制的无源动态调谐滤波器，因为普通的单调谐滤波器的电容会随着使用的时间以及环境的改变而造成电容值变小的问题，这样就会造成谐振点偏移，从而使滤波效果下降，所以就须要设计一款电抗器可以调节的滤波器解决这个问题。
本文主要完成的内容大致分为四个部分，
（1）无源动态调谐滤波器的主电路设计。主电路主要分为两个部分，有可变电抗器原边电路，包括电容器组和可变电抗器以及投切开关这些构成，然后就是可变电抗器的副边电路，主要由反向并联晶闸管以及保护电路构成，最后就是控制电路的电气设计，主要内容有开车停车按钮，以及各种情况的指示灯电容投切的电路等等构成。
（2）无源滤波器的控制系统设计。控制器选择的是西门子S7-200，程序的主要任务就是谐波信号的采集与处理，控制电容器的投切这些功能。
（3）滤波器仿真。本次设计中采用的仿真软件是MATLAB，这款软件功能强大，而且模型库中有各种电气设备的某型，只需要选择需要的模型，并将其按照设计好的系统拓扑图连接后，设置好参数既可仿真，可以用示波器等模型检测仿真线路中的功率和电流电压等波形，通过不断改变参数加分析波形就可以分析出结果，不需要实物就可以进行实验，大大方便和简化了工作，系统的仿真模型主要分为三个部分，三项电源，非线性负载以及无源动态调谐滤波器，这些部分都可以用模型库中的模型直接搭建。
（4）系统的改进与优化。使用寿命较短的器件或者结构可以采取改变结构等方法进行替换，使系统的成本和性能指标相对更符合实际情况。
本次研究将更好的推动无源滤波器的发展，使之不仅仅有滤波功能，还具有自动调节的能力，随着科技的不断发展，自动控制必然会在越来越多的事务上体现，另外本次设计也更加有利的契合了当下节能减排的社会总体趋势，具有良好的应用前景和价值。
关键词：PLC；无源滤波器；动态调谐；电容投切
 
            Abstract
The theme of this design is based on PLC-based passive filter research. With the popularity of electric power and its continuous application, electric energy has become the most important energy source at present, and with the increasing popularity of electric energy usage, some problems have also become prominent, due to power electronics and non-linear loads in the power grid. The ever-increasing number of harmonics in the power grid is becoming more and more complicated and serious. Harmonics is an energy pollution. If left unchecked, it will cause great harm, such as damage to equipment, misjudgment in the system, etc. Therefore, the governance of harmonics is becoming more and more important. The main content of this research is to design a passive dynamic tuning filter based on PLC control, because the capacitance of ordinary single-tuned filter will have smaller capacitance value as the time of use and environment change. This will cause the resonance point to shift, which will reduce the filtering effect, so it is necessary to design a filter that can be adjusted by the reactor to solve this problem.
The main content of this thesis is roughly divided into four parts.
(1) The main circuit design of the passive dynamic tuned filter. The main circuit is mainly divided into two parts, including the primary circuit of the variable reactor, including the capacitor bank and the variable reactor and the switching switch, and then the secondary circuit of the variable reactor, mainly by the reverse The parallel thyristor and the protection circuit are constructed. Finally, the electrical design of the control circuit is mainly composed of a driving stop button and a circuit for switching the indicator capacitance in various situations.
(2) Control system design of passive filter. The controller selects the Siemens S7-200. The main task of the program is the acquisition and processing of harmonic signals, and the control of capacitor switching.
(3) Filter simulation. The simulation software used in this design is MATLAB. This software is powerful, and there are some types of electrical equipment in the model library. You only need to select the required model and connect it according to the designed system topology diagram. Set the parameters to simulate, you can use the oscilloscope and other models to detect the power and current voltage in the simulation circuit. By changing the parameters and analyzing the waveform, you can analyze the results. You can experiment without physical objects, which is greatly convenient and simplified. Work, the system's simulation model is mainly divided into three parts, three power supplies, non-linear loads and passive dynamic tuning filters, these parts can be directly built using the model in the model library.
(4) Improvement and optimization of the system. Devices or structures with short lifetimes can be replaced by methods such as changing the structure, so that the cost and performance specifications of the system are relatively more realistic.
This research will better promote the development of passive filters, so that it not only has filtering function, but also has the ability of automatic adjustment. With the continuous development of technology, automatic control will inevitably be reflected in more and more affairs. In addition, this design is more beneficial to the overall social trend of energy conservation and emission reduction, with good application prospects and value.
Keywords:PLC；passive filter；dynamic tuning；capacitor group switching
 
目录
第1章诸论    1
1.1 课题的研究背景和意义    1
1.1.1 研究背景    1
1.1.2 研究的意义    3
1.2 本次研究的主要内容    3
第2章无源滤波器的原理与主电路设计    5
2.1 无源滤波器的原理    5
2.2 滤波器主电路设计    7
2.3 主电路硬件参数的计算    9
2.3.1 电容参数计算    9
2.3.2 电感参数计算    11
2.4 操作回路设计    11
第3章无源滤波器的控制系统设计    13
3.1 控制系统的硬件设计    13
3.2 控制系统的软件设计    13
3.2.1 功能模块的设计    13
3.2.2 符号表的设计    14
3.2.3 梯形图的设计    15
第4章滤波器仿真    18
4.1 仿真模型的构成    18
4.2 仿真模型的设计    18
4.2.1 三项电源的仿真模型设计    18
4.2.2 非线性负载的仿真模型设计    19
4.2.3 滤波器的仿真模型设计    19
4.3 系统模型的仿真    22
第5章结论    23
参考文献    25
致谢    26