电子机电论文编号:JD084    包括大图,字数:31854,页数:79

目 录
摘要........................................................... I
Abstract .......................................................II

第1章绪论......................................................1
1.1无功补偿的定义与作用 ........................................1
1.2课题背景.....................................................2
1.3国内外研究现状...............................................3
1.4本文研究的主要内容 ..........................................4
第2章无功补偿原理及调节判据 ...................................5
2.1无功补偿的原理...............................................5
2.1.1电压损耗与电压损失率的计算................................ 5
2.1.2并联电容器补偿.............................................7
2.2并联补偿电容器的配置原则 ...................................11
2.3调节判据的选择..............................................11
第3章 主系统设计...............................................15
3.1主电路......................................................15
3.2电容器组投切及晶闸管过零电路比较 ...........................17
3.2.1电容器组投切方式..........................................17
3.2.2晶闸管电压过零触发电路 ...................................19
3.3器件的选型..................................................21
第4章 TSC控制装置的硬件电路设计................................24
4.1电压电流的转换..............................................25
4.2数据采集电路................................................28
4.3单片机及其扩展电路 .........................................33
4.4键盘及显示电路 .............................................39
4.5投切控制电路................................................42
第5章软件设计 ................................................46
社会经济效益分析...............................................50
结论.........................................................  51
致  谢 ....................................................... 52
参考文献...................................................... 53
附录1 ........................................................ 55
附录2 ........................................................ 61
附录3...................................................... .. 69

摘 要
无功补偿的方法多种多样，最常见的就是并联电容器补偿。低压动态无功补偿装置是采用交流采样的方法对三相电压和电流分别采样，每周期测出20个瞬时值，经AD574把模拟量转换为12位数字量，由有效值计算公式算出每相电压、电流和无功功率Q，利用电压和无功构成的综合判据通常规定了电压和无功的上下限，并把电压和无功平面分成9个区，根据电压和无功的综合控制方法，通过晶闸管控制电容器的投切对电压和无功实行综合调节，以保证电压在合格范围内，同时实现无功的基本平衡。。
本装置对三相无功分别补偿，采用晶闸管作为无触点开关，利用过零比较器可实现对电容器组的无过渡过程的快速投切，避免了合闸时产生冲击电流损坏电器元件。电容器组的投切方式采用编码投切，三组电容器按容量比1：2：4即可组合成7个容量等级，投切控制方便，经济效益显著。
控制电路主要由交流采样单元、外部扩展单元、显示单元、控制单元等组成，硬件紧凑，编程容易，控制简单。本装置对电网参数实时检测，对系统无功实行跟踪补偿。补偿效果快速、准确、安全、易于控制，应用前景十分广阔。

关键词   无功补偿    综合控制    晶闸管开关

Abstract
    Reactive compensation variety of ways, the most common is the shunt capacitor compensation. LV dynamic reactive compensation devices is the use of sampling methods for three-phase voltage and current, respectively sampling, week period measured 20 instantaneous value, AD574 conversion from analog to digital 12. RMS calculated by the formula calculated for each phase voltage, current and reactive power Q, the use of voltage and reactive composition of the criteria usually provides the voltage and reactive power of the lower and upper limits and voltage and reactive plane divided into nine districts, according to the voltage and reactive power integrated control method, thyristor controlled by the switching capacitor pair of voltage and reactive power integrated regulate in order to ensure that qualified voltage range, Reactive while achieving the basic balance.
The device respectively compensation three-phase reactive, using thyristor as a non-contact switch, Comparing the use of zero for the capacitors can be realized without the group's rapid transition to the top, Closing avoid the shocks arising from the current damage to the electrical components. The capacitor switching is used for encoding all three groups capacitor capacity by more than 1 : 2 : 4 will be combined into seven levels of capacity, switching control convenience, significant economic benefits.
Control circuit mainly include the exchange of sampling unit, the external expansion unit, display units, the control unit and other components, compact hardware, Programming easy, simple control. The device to real-time detection of network parameters, the system implemented tracking reactive compensation. Compensation results fast, accurate, safe and easy to control, very broad application prospects.

Key  words  reactive compensation   comprehensive control   thyristor switches