无功功率优化研究开题报告葛祥

1、石河子大学毕业论文(设计)开题报告课题名称： 配电网无功功率优化研究 学生姓名： 葛祥 学 号： 2010509017 学 院： 机械电气工程学院 专业、年级： 10级电气工程及其自动化 指导教师： 王洪坤 职 称： 讲师 毕业论文(设计)起止时间 2014-3-1至2014-6-1 一、课题的目的及意义无功功率补偿优化问题就是找出补偿位置及容量的问题，它是一个在满足约束条件下求目标函数极值的复杂非线性问题。因目标函数与约束条件的非线性、控制变量的离散性与连续性相混合等特点，其问题的关键集中在对非线性函数的处理、算法的收敛上和如何解决离散变量的问题。而配电网无功优化是指合理配置无功补偿设备，合

2、理安排运行方式，优化无功潮流分布，进步无功治理水平，从而改善城市电网功率传输和电压质量，减少受端无功功率损耗，进步功率因数，降低网络损耗，进步发、供电设备利用率，进步无功补偿设备运行水平。无功补偿一般根据分区分层就地平衡的原则，采用集中补偿和分散补偿相结合的方式，高压配电网般在变电站集中补偿，中压配电网多采用分散补偿方式。2、 国内外研究现状在无功优化配置方面，闻内外已经形成了比较成熟和完善的算法早起最简单的无功功率补偿算法是由Neagle和Samson提出来的，假设无功负荷沿线均匀分布，只考虑支路电流无功部分变化引起损耗减少，且忽略节点电压变化而得到的2/3法则。但是该简单计算方法只对梳状网

3、而非树状网，因此如何将树状网简化成梳状网，将会是影响计算结果的关键所在。接着就是各种传统的数学规划法，如线性规划法、非线性规划法、混合整法、动态规划法等，及围绕这些算法的一些该进完善。其中较为引人注目的是最近几年兴起的一些人工智能方法，如遗传算法、模拟退火法、模糊集合理论以及规划和智能法相结合的功率矩法，但是我国在实施和运行方面还有在一定的差距。在我国的城市配电网建设和运行中，长期存在着无功补偿容量不足或分组不合理的问题，造成部分地区补偿装置投切不灵活，甚至无法投运。由于无功缺乏统一的规划和优化，造成资金的极大浪费。实行配电网无功优化技术，有针对性地进行无功补偿，具有非常大的经济效益和社会效益

4、。目前，我国电力网平均线路功率损耗比国外发达国家高出24个百分点。就全国讲，线路gesep全球节能环保网损耗约占据12%，其中主要是无功分量引起的损耗，若无功线损降低50%60%，一年便可节电500亿kWh左右，相当于半个三峡工程的发电量。这种不消耗一次能源，便可增大发电量的工程是绝好的绿色工程，且投资极小，见效快。三、研究内容及预期目标研究内容：（1）学习配网无功功率优化的工作过程。（2）利用粒子群算法计算解决配网无功功率优化问题。（3）总结配网无功功率优化设计，对理论结果与测试结果进行分析。（4）根据配电网络的要求，做配电网络功率优化设计。从而解决配电网络无功功率耗费过大的问题。预期目标：

5、（1） 在无功功率优化配置中加入了经济性的考虑，并且应用经济学原理讲投资析算成等年值进行计算，使优化工作更符合实际应用的需要。（2） 应用粒子群算法参与补偿点的选取优化，并根据配网的实际情况将粒子群算法改为更适合节点选择的二进制算法。因为节点的选择只有补偿和被补偿两种状态，二进制的位数1和0能很好地代表补偿和不补偿两种状态，这种该进使得粒子群算法更适用于配网网络的补偿点优化。（3）综合三种负荷状态进行网损的计算，将系统分为最大负荷、一般负荷、最小负荷三种状态，并且根据实际情况将其运行时间比率设为0.25、0.5、0.25.从而避免了只考虑单一负荷的片面性，同时又使网损的计算能够更好地符合实际情

6、况，达到促进优化精确性的效果。（4）应用本文所提出的粒子群算法对某12节点配网及某28点节点配电网络进行无功补偿优化设置，充分证明该方法的合理性和有效性。4、 工作方案及进度计划阶 段日 期 安 排 开题报告 2014年2月20日2014年3月1日 查询文献，进行整理与阅读 2014年3月2日2014年3月15日 完成课程设计技术方案 2014年3月16日2014年3月20日 完成各功能设计 2014年3月21日2014年4月22日 整理论文完成论文初稿 2014年4月23日2014年5月1日 论文定稿 2014年5月2日2014年5月25日五、参考文献1张伯明、陈寿孙，高等电力网络分析，清华

7、大学出版社，19992靳龙章、丁毓山，电网无功补偿实用技术，电力自动化设备，20013.李剑虹.顾绍柱.卢志刚.韩彦玲 配电网运行经济性评价期刊论文 - 华北电力技术 2008(2)4杨维，粒子群算法综述，中国工程科学，2004 5王成山，张义基于Benders分解和内点法的无功优化规划J电力系统及其自动化学报， 2003 6李林川，王建勇，陈礼仪，等电力系统无功补偿优化规划J中国电机工程学报，1999 7许文超， 郭伟 电力系统无功优化的模型及算法综述J 电力系统及其自动化学报，2003，(15)：100104指导教师审阅意见： 指导教师（签字）： 年 月 日备注： 文献综述绪论： 改善工业

8、企业用电的功率因数是提高用电效率、节约电能的重要手段。本文通过理论分析和应用实例说明了工业企业无功补偿的意义和作用，并针对目前工业企业供用电系统存在的问题，提出了改进意见和措施。1 引言在工业企业中，绝大多数的用电设备属于感性负荷，这些设备在运行中要吸收大量的无功功率。无功功率的增加使供电系统的功率因数降低，从而出现系统电压下降、电气设备得不到充分利用、增加线路损耗以及降低供电设备的供电能力等情况。因而就地进行无功补偿、提高功率因数对降损节能有着极为重要的意义。2 补偿方式的选择无功补偿分为集中补偿、分散补偿和就地补偿三种。集中补偿，即在高、低压配电所内设置若干组电容器，电容器接在配电母线上，

9、补偿该配电所供电范围内的无功功率，并使总功率因数达到规定值以上。这种补偿方式只能补偿高、低压母线之前线路上的无功功率，它们相当于把无功功率源移到用电企业的配电所，使用户对供电系统要求的无功功率有所减少，达到供电部门所要求的功率因数。而它们对配电母线以下的企业内部的变压器和线路的无功功率不能起到补偿作用，仍有大量的无功功率在企业内部线路上流动并产生损耗。分散补偿是将电容器组分别安装在各个车间的配电盘处，这种安装方式可以使配电变压器以及变电所至车间的线路都可以由于无功负荷的减少而获得补偿效果。就地补偿是把无功补偿器直接接在异步电动机旁或进线端子上。集中补偿方式所用电容器组的容量较分组补偿或就地补偿

10、要小，它的利用率则更高，缺点是对变、配电所各馈线并未得到补偿，仅减轻了电网的无功负荷。分散补偿方式中的电容器组的利用率比就地补偿高，因此总需要量较就地补偿要小，是一种经济合理的补偿方式。无功补偿应遵循“全面规划，合理布局，分级补偿，就地平衡;集中补偿与分散补偿相结合，以分散补偿为主；高压补偿与低压补偿相结合，以低压补偿为主；调压与降损相结合，以降损为主”的原则。3 补偿容量的确定在电力网中无功功率的消耗是很大的，大约50 %的无功功率消耗在输、变、设备上，50 %消耗在电力用户上。为了减少无功功率消耗，就必须减少无功功率在电网里的流动。最好的办法从用户开始增加无功补偿，提高用户负荷的功率因数，

11、这样可以减少发电机无功出力和减少输、变、配电设备中的无功电力消耗，从而达到降低损耗的目的。补偿的无功功率容量为式中最大负荷日平均有功功率；未装设补偿装置前的功率因数实测值；装设补偿装置后所达到的功率因数值。4 无功补偿装置的作用可以根据负荷变化情况决定采用静态还是动态补偿方式。当负荷变化较为平稳时，应采用静态补偿方式，这不仅能较好地降低线路损耗，而且投资少;当负荷变化较大时，应采用动态补偿方式，稳定电压。4.1 降低线损设在某一额定电压下，有功功率恒定不变，由于功率因数变化，其线路损耗变化率P %为从表4.1中可以看出提高功率因数对于降低电能损耗，提高经济效益具有十分重要的作用。表4.1功率因

12、数与有功损耗百分率的对应数据若在恒定有功功率条件下，原有的功率因数为0.60，补偿后的功率因数为1，0时，其线损率降低%为64 %。采用动态补偿装置，将电力电容器分组跟踪补偿，则可由原来不同的功率因数稳定在所规定的功率因数范围内，达到充分补偿的目的。4.2 线路、变压器的增容线路、变压器的增容量S 为加设补偿装置后，可提高功率因数，对企业的直接功率因数经济效益是明显的。因为国家电价制度中，从合理利用能源出发，依据企业的功率因数值来调整电价高低。这种补偿装置对企业和整个电力系统的经济运行都有着重大的经济效。4.3 改善电压质量改善电压质量是指装设动态无功补偿装置前后，作用在补偿地点的线路电压稍有

13、提高。式中未装设补偿装置前角的正切；装设补偿装置后角的正切；R 、x 线路的电阻、电抗。5 工业企业供用电系统存在的问题与解决措施图1为某重型机床厂供电系统示意图。目前，该厂变压器总容量为17660kVA ，共有20台变压器(1 # 20 # 变压器) ，每台变压器的容量范围为501250 kVA ，变比为10kV/ 014kV。变压器低压侧负载主要为电动机，如图中M1 、M2 Mn 所示。一般情况变压器负载率基本上维持在28 %29 %之间，最大负载时为7000kW。5.1 采用高、低压相结合的补偿方式取代高压集中补偿从图中可以看到该厂供电网络的功率因数补偿是高压集中补偿，即只在变电所10k

14、V 的高压母线上接电容器组，而低压却没有采取任何补偿措施。这种固定电容器补偿的方法会出现过补偿或欠补偿的情况，并且对二次母线以下的供电线路的功率因数补偿不起作用。由于功率因数低而造成的线路损失和变电设备的损失是很大的，所以补偿时要尽量做到分级，靠近负载处安装电容器。因而提出高压侧集中补偿和低压侧分散补偿相结合的补偿方式。图5.1某重型机床厂供电系统示意图5.2 改变供电方式，尽可能避免“大马拉小车”的现象在设备选型时，要考虑留有一定的容量，防止重载时损坏设备，这样大部分时间都造成设备欠载和严重欠载形成“大马拉小车”运行。由于该厂变压器的负载率基本上在28 %29 %之间，说明变压器的装机容量过

15、大，变压器容量不能充分利用，既浪费了设备投资又增加了电能损耗。可以通过合理选择变压器的容量以及减少或限制用电设备轻载或空载的时间来防止“大马拉小车”现象。5.3 避免设备的空载运行目前，该厂某些设备的空载运行严重。在提高功率因数时，首先应考虑使设备合理运行，提高耗电设备本身的功率因数。该厂主要负荷是交流电动机，其功率因数随它的负载而改变，电动机在空转时，功率因数约在0.10.3 之间，额定负载时在0.80.85 之间，因而应使电动机接近额定负荷状态下运行。要把电动机功率因数提高，最简单的办法是用电容器和电动机并联，所以避免设备的空载运行是提高设备功率因数的重要途径。5.4 建议完善配电设备或对

16、其进行重新改造在现场测量数据的过程中，我们发现很多配电设备老化现象严重，没有电流表、电压表或者读数不准确，如镗床车间的配电房内完全没有电流表和电压表。6 经济效益分析以该厂供电系统中的2 # 变压器为例，在低压侧加装电容器，使该厂采取高压侧集中补偿和低压侧分散补偿相结合的补偿方式，如图6.1 。图中2 # 变压器容量为800kVA ，型号为S9 - 800/ 10 ，额定铜损耗为 = 715kW ，输电线路型号为YJV22 。取电价为0.55元/ kW.h 。将功率因数由补偿前的0.59提高到补偿后的0.98 ，表6.1是利用测量仪器在现场测得的变压器运行时二次侧数据，现通过计算分析无功补偿降

17、损节能效益。图6.1铸造车间供电图表6.1 变压器运行时二次侧数据表6.1 高压供电线路节电全年节约电能W =h式中增加的线路电功率，h 年运行小时数，取5000h 。经计算全年节约电能162217kW.h ，一年内降低的电能损耗费8192万元。6.2 变压器节电变压器的损耗主要有铁损和铜损。提高变压器二次侧的功率因数，可使总的负荷电流减少，从而减少铜损。全年节约变压器铜损耗电能h 式中补偿前变压器实际运行时的铜损耗电功率PCu2 补偿后变压器的铜损耗电功率经计算全年节约电能3150kW.h ，一年内节约变压器铜损耗电费173518元。6.3 功率因数调整电费用户一年内减少因功率因数偏低多支出

18、的罚金:800 0. 5895000 0.55 17.22 %(增收率) =22131万元补偿后用户一年内得到的功率因数奖金:800 0. 589 5000 0.55 2.7 %(减收率) =315万元两项总计为25181万元由上述计算可知一年内合计增加纯收入34173万元，根据补偿容量需设备投资2715万元，9个月就能收回投资。这说明针对该厂铸造车间的具体情况在变压器二次侧采用分散补偿的方式进行无功补偿是可行的，并且能取得长期且明显的经济效果。 Industrial enterprises of reactive power compensation From:Power System An

19、alysis and DesignAbstract The improvement of industrial enterprises is to improve the power factor of electric power efficiency， an important means of saving energy. In this paper， theoretical analysis and application examples of the industrial enterprises， the significance of reactive power compens

20、ation and the role and view of the current power system， industrial enterprises， the problems for the proposed improvements and measures. Introduction In industrial enterprises， the vast majority of electrical equipment belongs to perceptual load， these devices in operation to absorb a large number

21、of reactive power. An increase in reactive power supply system power factor to lower system voltage drop to occur， electrical equipment not fully utilized， increasing line losses and lower-powered equipment， power supply capacity and so on. In situ reactive power compensation and thus improve the po

22、wer factor of the Energy Conservation has extremely important significance. The choice of method of compensation Compensation for reactive power compensation is divided into centralized and decentralized compensation for three kinds of compensation and in situ. Focus on compensation， that is， high a

23、nd low voltage power distribution set up by several groups within the capacitor， capacitor connected to the power distribution bus， the compensation for the distribution of power within the reactive power， and to reach the required value of the total power factor above. This method of compensation c

24、an compensate for high and low voltage bus routes prior to the reactive power， which is equivalent to the reactive power source to move the electricity distribution companies， allowing users to power the system requirements for reactive power has been reduction in the electricity sector to achieve t

25、he required power factor. And their distribution within the enterprise bus following the line of transformer and reactive power compensation can not play a role， there is still a large number of reactive power line flows within the enterprise and generate losses. Dispersion compensation is the capac

26、itors were installed at various workshops at the switchboard， which will enable installation of distribution transformer and the substation to the plant lines can be due to a decrease in reactive load compensation effect. Local compensation is the reactive power compensation device directly connecte

27、d to the induction motor terminals on the side or into the line. Focus on compensation methods used in the capacity of capacitor compensation or in-place than the grouping of compensation should be small， its utilization rate is even higher disadvantage is the change in distribution has not been com

28、pensated by the feeders， only lightened the load reactive power grid. Dispersion compensation in the way the utilization of capacitor compensation than the in situ high， so the total requirement of compensation is smaller than the spot is an economical and reasonable remedy. Reactive power compensat

29、ion should follow the overall planning， rational distribution， classification of compensation， in-place balance; focus on compensation and dispersion compensation combine to spread-based compensation; high compensation and low voltage compensation combined with low-pressure-based compensation; Regul

30、ator combined with lower losses， down are the main loss principle 1. Compensation capacity to determine In the power grid in the reactive power consumption is a big， about 50% of the reactive power consumed in transmission， transformation and the device， 50% of the consumed electricity users. In ord

31、er to reduce reactive power consumption， it is necessary to reduce the reactive power in the grid where flow. The best way to start from the user to increase reactive power compensation， improve user load power factor， so that Generator reactive power can be reduced and the reduction of transmission

32、， transformation and distribution equipment in the reactive power consumption， so as to achieve the purpose of reducing wear and tear 2. Compensation for reactive power capacity of Qc for Load changes can be decided according to the static or dynamic compensation mode. When the load change is relati

33、vely stable， we should use the static method of compensation， which can not only reduce the line losses， and investment; when the load change is large， dynamic compensation method should be used， stable voltage 3. Reduce line lossesIs located at a rated voltage， active power is constant， due to powe

34、r factor changes， the line loss rate of change P% for the As can be seen from Table 1 to improve the power factor in lowering power consumption， improving economic efficiency plays an important role. Table 1 Power factor and power loss percentage of the corresponding data If a constant active power

35、condition， the original power factor cos1 of 0.59， compensated power factor cos2 of 0.98， its line loss rate reduction % to 64%. Dynamic compensation device， Group to track the power capacitor compensation， power factor can be different from the stability provided in the context of the power factor

36、to achieve adequate compensation purposes. Lines， transformer capacity increase Lines， transformer capacity increased S for the Additional compensation device， may improve the power factor， power factor on the business of direct economic benefit is obvious. Because the state electricity system， star

37、ting from the rational use of energy， according to the power company to adjust the price due to high and low values. The compensation device for enterprise and the entire power system economic operation all have significant economic effects . To improve the voltage quality To improve the voltage qua

38、lity is the dynamic reactive power compensation equipment installed around the role of place in the line voltage compensation has increased slightly . Where tg1 - compensation device is not installed before the 1 angle tangent; tg2 - compensation equipment installed after the 2 angle tangent; R， x -

39、 line resistance， reactance. Industrial enterprises for the power system problems and solution Fig 1 for a diagram of power supply systems for heavy machine tool plant. At present， the total capacity of the plant transformer 17660kVA， a total of 20 transformers (1 # 20， # transformers)， each transfo

40、rmer capacity range of 50 1250 kVA， changing the ratio of 10kV / 014kV. Transformer low voltage side of the load is mainly motor， shown in the M1， M2 Mn shown. In general the rate of transformer load is basically maintained at 28% 29%， and the maximum load of 7000kW. High and low voltage compensatio

41、n to replace a combination of high concentration of compensation From the figure we can see the plant supply network focused on high-voltage power factor compensation is compensation that is only in the high-voltage busbar 10kV substation capacitor banks on the pick， while the low pressure has not t

42、aken any compensation measures. The fixed capacitor compensation method there have been compensation or due compensation， and right below the second power supply bus power factor compensation circuit does not work. As the low power factor caused by the line losses and transformer equipment is a big

43、loss， so compensation as far as possible when grading， installation of capacitors near the load. Therefore proposed that the high side to focus compensation and dispersion compensation for low-voltage side of a combination of method of compensation . Figure 1 Power Supply System of a Heavy Machine T

44、ool Plant diagramTo change the power supply as much as possible to avoid the big horse-drawn cart phenomenon In making our selection， we should consider leaving a certain margin， to prevent heavy damage to equipment when， so most of the time caused by equipment， and severe underrun underrun the form

45、ation of the big horse-drawn cart Run. As the plant load factor of the transformer is basically 28% 29%， and shows the transformer capacity is too large， transformer capacity can not be fully utilized， not only a waste of investment in equipment has increased the power loss. Rational choice by the t

46、ransformer capacity and electrical equipment to reduce or limit the light-load or no load time to prevent the big horse-drawn cart phenomenon. To avoid the no-load operation of equipment At present， the plant is running a serious load of some equipment. Improving the power factor， the first consider

47、ation should be given a reasonable run the equipment to improve power factor of power the device itself. The plant main load is AC motor， its power factor load with it change， motor idling， the power factor of about 0.1 0.3 between the rated load at 0.8 0.85 between the motor and thus should be made

48、 near the rated load state run. We should improve the motor power factor， the simplest way is to use capacitors and electric motors in parallel， so to avoid the no-load operation device is to improve the power factor equipment， an important way. Economic Benefit Analysis To the factory power supply

49、system in two # transformers， for example， installation of capacitors in the low voltage side， so that high-pressure side of the plant to focus on compensation and dispersion compensation combination of low-voltage side of a compensation formula， shown in Figure 2. Graph 2 #transformer capacity of 8

50、00kVA， model S9 - 800 / 10， rated copper loss for the 715kW， transmission line model YJV22. Get price of 0.55 yuan / kWh. The power factor by the compensation prior to 0.59 to compensate for post-0.98， Table 2 is the use of measuring instruments measured in the field of transformer secondary side ru

51、n-time data are analyzed by calculating the loss of reactive power compensation reduced energy efficiency. Figure 2 foundry supply diagram Table 2 transformer secondary-side run-time data tableThe energy-saving high-voltage power lines Throughout the year to save electricity W = hWherel- the increas

52、e in electric power lines，The number of annual operating hours， whichever 5000h. The calculation of annual energy savings 162217kW.h， within one year to reduce electricity consumption costs 81.92 million yuan. Transformer-saving The loss of main transformer iron loss and copper loss. Transformer sec

53、ondary side to improve the power factor， can reduce the total load current， thereby reducing the copper loss. Transformer copper loss of the year to save energy W = (PCu1 - PCu2) h where PCu1 - compensation for the actual run-time before the transformer copper loss of electric power， PCu2 - compensa

54、ted transformer copper loss of electric power， The calculation of annual energy savings 3150kWh， within a year to save electricity transformer copper loss of 173，518 yuan. Power Factor Adjustment tariff Users within a year to reduce spending more than the low power factor penalty: 800 0. 589 5000 0.

55、55 17.22% (increase rate) = 221.31 million yuan of compensation within one year after the users get the power factor bonus: 800 0. 589 5000 0.55 2.7% (reduced rate) 3.15 million total of 251.81 million yuan from the two above calculations we can see an overall increase within one year of net income

56、341.73 million yuan， according to the capacity required to compensate for equipment investment 27.15 million yuan， 9 months will be able to recover their investments. This shows that the plant foundry for the specific circumstances of the transformer secondary side compensation for use of decentralized approach to reactive power compensation is feasible and can achie