毕业设计 360kVar低压无功补偿装置的设计.doc

摘 要 电网向用电设备提供的负载电流由有功电流和无功电流两部分组成，无功电流在电网和负载之间往复交换，大大占用电网供电容量，使供电设备的供电能力大大下降。动态无功功率补偿装置的基本原理就是用装置产生的容性无功电流实时、快速、准确地抵消电网中的感性无功电流，从而提高了功率因数，保证了用电质量，提高了供电设备的供电能力，并减小了电路中的损耗。因此无功功率补偿在电力系统中是一项重要的工作，根据企业的自身实际需要通过自动投切电容器来达到无功补偿的效果，以此达到保证功率因数质量的目的。本次设计原理是以功率因数和电压为考虑对象综合决策制定投切电容器，并通过控制单元检测电压，电流，计算功率因数和无功功率，然后与电压，无功功率上下极值相比较 ，最后作出控制决策（投入或切除电容）。本次设计针对360KVAR配电系统提出的无功补偿需要而设计的一套无功补偿智能控制系统，而且结合接触器投切准则。同时，由于无功量增加会导致电压的抬高，因此本文采取电压，无功补偿量的综合考虑控制方式来进行电网的无功补偿。 关键词：无功功率，无功补偿，控制器，接触器，功率因数  Abstcact Power grid to electrical equipment by the load current provide meritorious electric current and reactive current two parts, reactive current between grid and load in reciprocating exchange, greatly occupies grid power supply capacity to make power equipment power supply dramatically reduced. Dynamic reactive power compensation device with the basic principle is the deice producing capacitive reactive current real-time, quickly and accurately offset the perceptual reactive current power, thereby improving power factor, and to ensure the quality of power supply equipment, improved the power supply, and reduce the loss of a circuit. So reactive power compensation in power system is an important work, according to the enterprise itself actual need through auto-switching capacitor to achieve the effect of reactive power compensation, to ensure the quality of power factor of purpose. The design principle is to consider the voltage of power factor and comprehensive decision-making object, and through cast cut capacitor control unit testing voltage, current, computational power factor and reactive power, then, reactive power and voltage fluctuation extremum, compared to control decision-making (last invested or resection capacitors).360KVAR distribution system for the design of reactive power compensation need to put forward a set of designed reactive power compensation, and intelligent control system with contactor threw cutting criteria. At the same time, because of reactive power will lead to in