基于分布式电源的低电压治理探究

发布时间：2018-04-29 12:43

本文选题：农村配电网 + 光伏发电　；参考：《沈阳农业大学》2017年硕士论文

【摘要】：随着工厂企业在城市中的经营成本越来越高,企业和工厂开始转向乡镇农村发展,直接推动了农村经济发展,从而农村居民生活水平也得到了提高,再加上国家推行的家电下乡政策和农村机械化,农民家用电器和生产机械得到飞速发展,农村用电量远远超过了目前的既有容量,为满足高质量的生活生产活动,农村电网广大电力用户迫切追求更高的电能质量。而用电量的猛增,加上农民居住比较分散,供电线路长,导线线号细等因素直接导致线路末端电压降低,使农民生活和生产电器无法正常运转,农民经济生产活动受到了极大的约束。针对电压低,电力公司传统上只能被动的通过停电调节分接头、更换大容量变压器、增加变电站或供电线路、优化供电半径、更换大截面的导线和配置其他无功补偿设备来弥补压降,可是若对设备进行高规格配置,一年中大部分时间又会出现"大马拉小车"的现象,极大增加了电能浪费且投资巨大,电力公司和用电客户亟需一种新的解决办法。本文就是以天津宝坻地区一个典型农网380V线路低压台区为模型光伏并网项目,采用ETAP(Electrical Transient Analysis Program)电力系统计算分析软件搭建系统模型,仿真分布式光伏容量、并网接入位置以及光伏发电功率因数变动时,农网末端电压变化规律,并在光伏发电波动性时,模拟静态无功发生器(SVG)对电压的调节作用,得出分布式光伏接入电网,可以一定程度的改善电压损失,改善的程度与用户负荷,线路参数,接入位置和光伏总出力密切相关;不同发出功率的单个光伏接入后,配电网的节点电压与DG注入容量有关,注入容量越大,配电网的节点电压得到的支撑也越大;DG接入点电压的抬升情况与DG接入节点与电网电源端的距离呈正比关系;分散接入DG比集中接入DG的电压提升电压更均匀;功率因数滞后优于功率因数超前改善电压的状况;采用ETAP软件验证采用并接SVG的方式抑制电网的波动性,理论上证明了加装SVG对于大量光伏并网的农网地区的电压闪变和无功补偿有着明显的效果。为今后正确规划分布式电源并网从而能够提升末端电压和电压质量提供详细的理论佐证和实践指导。
[Abstract]:As the operating costs of factory enterprises in the city become higher and higher, enterprises and factories begin to turn to township and rural development, which directly promotes the development of rural economy, thus improving the living standards of rural residents. Coupled with the country's household appliances policy and mechanization in rural areas, farmers' household appliances and production machinery have developed rapidly. Rural electricity consumption has far exceeded the existing capacity, in order to meet the high quality of life production activities. Rural power users are eager to achieve higher power quality. However, the surge in electricity consumption, coupled with the scattered living of farmers, the long power supply lines and the thin wire number, directly led to a decrease in the voltage at the end of the line, which caused the farmers to live and produce electrical appliances that could not function normally. The farmer economy production activity was subjected to the great restraint. In view of the low voltage, power companies have traditionally been able to passively adjust the tap through power outages, replace large capacity transformers, increase substations or power supply lines, and optimize the power supply radius. Replacing large-section conductors and installing other reactive power compensation equipment to compensate for pressure drop, however, if the equipment is configured in a high standard, the phenomenon of "cart pulling" will appear again for most of the year, which greatly increases the waste of electric energy and the huge investment. Power companies and customers desperately need a new solution. This paper takes a typical low voltage platform area of 380V line in Baodi area of Tianjin as a model photovoltaic grid-connected project, uses ETAP(Electrical Transient Analysis Program to build the system model and simulates the distributed photovoltaic capacity. When the grid-connected position and the power factor of photovoltaic power are changed, the voltage changes at the end of the rural power grid, and when the photovoltaic generation fluctuates, the voltage regulation of the static reactive power generator (SVG) is simulated, and the distributed photovoltaic access network is obtained. The voltage loss can be improved to a certain extent, and the degree of improvement is closely related to the user load, line parameters, access location and total PV output, and the node voltage of the distribution network is related to the DG injection capacity after a single photovoltaic connection with different emitting power. The larger the injection capacity, the larger the support of the node voltage of the distribution network, and the higher the voltage uplift of the DG access point is, the higher the distance between the DG access node and the power supply is, the more uniform the voltage lifting voltage is when the DG is distributed than the centralized access DG. The power factor lag is better than the power factor to improve the voltage in advance. The ETAP software is used to verify the use of parallel SVG to reduce the power grid volatility. It is proved theoretically that the addition of SVG has obvious effect on voltage flicker and reactive power compensation in a large number of grid-connected rural areas. It provides detailed theoretical evidence and practical guidance for correctly planning the grid connection of distributed power supply and improving the terminal voltage and voltage quality in the future.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM727.1

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