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输配电网中运用无功补偿的意义研究
发表日期:2013-08-04 08:52:35 | 来源:assignment.cc | 当前的位置:首页 > 写作FAQ > 正文
First, the distribution of the importance of reactive power compensation
Currently set off a worldwide wave of environmental protection, electric power system is a specific environment, appearing in the transmission and distribution network reactive power, power itself is determined by operation of the law, but it gives a lot of trouble grid operation . Reactive power is both can not be active, but it will cause losses in the grid, and it is not a lack of power, so you want to add in the grid reactive power compensation device, while the grid voltage is adjusted achieve power efficiency maximized.
 
Second, the distribution of reactive power compensation? 1 grid reactive power compensation  
Reactive power compensation of the basic principles are: stratified according to the voltage at the grid partition, local equilibrium, avoiding long-range transport of reactive power, so as not to take up the line to increase transmission capacity and power loss. Most no direct supply grid load, generally do not set up for the purpose of regulating reactive power compensation device. Parameters used for longer distances compensated transmission lines. Specific compensation method is as follows:
 
(A) reactor compensation
Reactors are commonly used in EHV transmission lines over long distances compensation device to compensate for transmission line-to-ground capacitance charging power generated to suppress power frequency overvoltage. The capacity of the reactor length and over-voltage limiting circuit level selection, the degree of compensation (reactor capacity and line charging power ratio) to statistics mostly 70-85, the individual is 65, generally not less than 60. Reactor general often set in the line two turbulent, and does not set the circuit breaker.
(2) series capacitor compensation
Series capacitor is used to compensate for transmission line inductance, improving stability play a shortened electrical distance transmission capacity levels and the role of the line. Series capacitor banks, mostly in series or parallel combination of parallel count by the line transmission capacity, depending on the series by the required number of series capacitor compensation degree (series capacitor compensated line capacitance and inductance ratio) be. Series capacitor compensation is generally below 50, not too high, so as not to cause the system to sub-synchronous resonance. Grid impedance caused by uneven due to circulation, the series capacitor can also be used to compensate. Japan 110kV ring on the use of series capacitor compensation.
(3) intermediate synchronous or static compensator
The intermediate transmission line installed in the remote camera or static synchronous compensator compensating means, use of these devices of reactive power regulation, the line absorbs light load line charging power, limit the voltage rise; issued when the line reactive power overload, to compensate for line reactive power loss, support for voltage levels, thereby increasing the transmission capacity of the line. Middle synchronous or static compensator usually located in the midpoint of the line, assuming that the first end of the line, adjust the effect disappeared.
Anchor with the grid voltage regulator and the power transmission grid region's low a voltage grids associated pivot point, often set OLTC or a substantial ability to regulate and control the reactive power compensation device, or two who have, in order to achieve the central point regulator, so that the operation of the grid is not less affected by the trend changes or other reasons due to the formation of voltage fluctuations in the power grid accident play a supportive role of voltage, and prevent the grid voltage fluctuations The expansion of the accident.
The strength of the voltage support capabilities, in addition to compensation and compensation capacity with the size, but also with the ability to control compensation device regulation and response speed. Although it is commonly used shunt capacitor compensation equipment and inexpensive, but its reactive power output when the voltage drop will be the square of the voltage drop is not conducive to supporting voltage. Instead, a large number of parallel compensation capacitor installed an incident fueled the possibility of the collapse of the grid voltage. Using synchronous condenser and static reactive power compensation device supported by appropriate regulation and control, is an ideal support voltage reactive power compensation device. In recent years, both at home and abroad focus on the application of static compensator.
(2) with reactive power compensation
Distribution network mainly in reactive power compensation phase compensation and guarantees the quality of the main users of electricity voltage. Specific methods for the phase compensation.
(A) phase compensation (also known as the power factor compensation
Electrical appliances mostly electromagnetic structure, requires a lot of excitation power, resulting in the user's power factor are slow and low, generally about 0.7 or so. Excitation power - lag phase reactive power flow in the distribution network, not only takes up distribution network capacity, resulting in unnecessary losses, and cause the user voltage decreases. Phase compensation is based on a phase of reactive power compensation equipment (such as shunt capacitor) nearest the user or distribution network supplying the required lag phase reactive power flows in the distribution network to reduce reactive power, reduce network losses, improve voltage quality. China for large power users require the installation of reactive power compensation device, power factor compensation shall not be less than 0.9.
Third, the grid voltage adjustment
To ensure that electrical appliances are in good working voltage, avoid being with voltage fluctuations damage electrical equipment, power distribution grid voltage needs to be adjusted. Grid voltage adjustment methods: central regulator, regulating transformers and reactive power compensation regulator regulator.
1. Use of regional power plant or substation hub for central regulator
This measure is simple and economical, convenient, but it can only change the voltage level of the entire supply area, can not improve the voltage distribution. When the supply relatively broad geographic area, power distances disparity, the central regulator measures are often not take into account the region, there are trade-off shortcomings.
2 tone regulating transformers
Can compensate for the lack of central regulator means for regulating local. Regulating transformer OLTC transformers, series booster and induction regulator three. OLTC with induction regulator is generally used for a specific load point, the series booster is used to power lines.
The role of regulating transformer regulator power network by changing the reactive power flow to achieve. It is in itself not only produce reactive power, but also because of their need for excitation and consume reactive power. When the grid is insufficient reactive power, voltage regulator transformer no significant effect. Conversely, if too much regulating transformers installed, will increase the distribution grid reactive power consumption, low voltage level of the whole network, increasing network losses, reduce reactive power of capacitors in parallel, may cause serious vicious cycle trend.
3 reactive power compensation regulator
Because of the increased power grid reactive power, can play a role in improving the grid voltage. Installed in substation reactive power compensation device, can be applied to the packet switching approach for the implementation of central regulator supply area.
4 series capacitor compensation regulator
Series capacitor compensation may be used for local distribution grid regulator. Heavy lines in long distance, because the role of regulator through the line current flowing through the phase lag generated by the series capacitor voltage rises to achieve. Therefore, the heavier the load line, the lower the power factor, the role of regulator series capacitor compensation more remarkable. This regulator role in line with the load change, with self-adjusting function.
 
 
首先,输配电网无功补偿的重要性
 
目前掀起了全球环保浪潮,电力系统是一个特定的环境中,出现在输电和配电网络的无功功率,电源本身的运作规律决定的,但它给了很多麻烦电网运行。无功功率是既不能是积极的,但它会导致电网的损失,而不是缺乏力量,所以你要添加的网格中的无功补偿装置,电网电压调整,实现电源效率最大化。
 
其次,分布无功补偿? 1电网无功补偿
无功补偿的基本原则是:根据电压在电网分区分层,局部平衡,避免远距离输送的无功功率,从而不占用线,以增加传输容量和功率损耗。最没有直供电网负荷,一般不设立调节无功补偿装置的目的。用于参数补偿输电线路更长的距离。具体的补偿方法是,如下所示:
 
(A)电抗器补偿
反应器中常用的超高压输电线路长距离补偿装置,补偿输电线路对地电容产生抑制工频过电压的充电电源。反应器的长度和过电压限制电路,电平选择,补偿度(反应器容量和线路充电功率比)的容量的统计数据大多为70-85,个别为65,一般不小于60。反应堆一般常设置在线两动荡,并没有设置断路器。
(2)串联电容补偿
使用串联电容,以补偿传输线的电感,提高稳定性起到缩短电气距离的传输容量水平和线的作用。串联电容器组,主要是在由线路的传输容量的并行计数串联或并联组合,这取决于串联电容补偿度(串联电容补偿线路的电容和电感比)是由所需数量的系列。串联电容补偿通常是50以下,不太高,从而不导​​致系统次同步谐振。电网阻抗的串联电容引起的不均匀,由于流通,也可以被用于补偿。日本110千伏环串联电容补偿的使用。
(3)中间同步或静止补偿
遥控相机或静止同步补偿器补偿装置安装在中间传输线,使用这些设备的无功功率调节,线路吸收轻负载线,充电电源,限制电压上升;发行时线路无功功率过载,以弥补线无功功率损耗,支持的电压水平,从而提高了线路的传输容量。中同步或静止补偿器通常位于线的中点,假设线的第一端部,调整效果消失。
锚的电网电压调节器和在电力传输电网区域的低一电压电网相关的枢轴点,常设置有载分接开关或实质性,以调节和控制的无功功率补偿装置能力,或两个谁都有,为了实现中央点稳压器,所以该操作的网格不小于受由于电网事故起到支撑作用的电压的电压波动的形成趋势发生变化或其他原因,电网电压波动,防止事故的扩大。
电压支撑能力的强度,除了赔偿和补偿容量的大小,同时也有能力控制调节补偿装置和响应速度。虽然通常使用并联电容器补偿装置和廉价的,但不利于支持电压的无功功率输出时的电压降的电压降的平方。相反,大量的并联补偿电容器安装的入射燃料电网电压崩溃的可能性。使用同步冷凝器和静态无功补偿装置通过适当的调节和控制的支持,是一个理想的支持低压无功功率补偿装置。近年来,在国内和国外专注于静态补偿器的应用。
(2)无功补偿
分销网络​​,主要集中在无功功率补偿相位补偿,并保证供电电压质量的主要用户。的相位补偿的具体方法。
(A)的相位补偿(也被称为功率因数补偿
电器用具大多电磁结构,需要大量的激励功率,导致在用户的功率因数是缓慢和低的,通常为约0.7左右。励磁功率 - 滞后相无功功率流的配电网络中,不仅占用了分销网络的能力,造成不必要的损失,导致用户电压下降。基于相位补偿的无功补偿设备(如并联电容器)相最接近用户或分销网络提供所需的滞后相无功功率流的配电网络中,减少无功功率,降低电网损耗,改善电压质量。中国大型电力用户的需要安装无功补偿装置,功率因数补偿不得低于0.9。
三,电网电压调整
为了确保电器都处于良好的工作电压,避免电压波动会损坏电气设备,配电电网电压需要进行调整。电网电压调整方法:中央稳压器,调压变压器和无功功率补偿式稳压器。
1。使用区域的电厂或变电站枢纽的中央稳压器
这项措施简单,经济方便,但它只能改变整个供电区域的电压电平,不能提高的电压分布。当供给相对广泛的地域面积,功耗距离差距,中央调控措施往往不考虑该地区,有权衡的缺点。
2音调压变压器
可以弥补缺乏中央调节装置,用于调节当地。调压变压器有载调压变压器,系列增压器和感应调压器三种。有载分接开关,感应调压器一般用于一个特定的负载点,该系列增压器的使用电源线。
调节变压器稳压电源网络的作用,通过改变无功功率流来实现。它本身不仅产生无功功率,而且,因为他们需要激发和消耗的无功功率。当电网不足,无功功率,电压稳压器变压器没有显着的效果。相反,如果安装了太多调压变压器,将增加配电网无功功率消耗,低电压等级的整个网络,增加网损,减少无功功率的并联电容器,可能会导致严重的恶性循环的趋势。
3无功功率补偿式稳压器
由于增加了电网的无功功率,才能发挥作用,在改善电网电压。安装在变电站无功补偿装置,可以应用到分组交换的方式实施中央稳压供电区域。
4串联电容补偿式稳压器
串联电容补偿可用于局部配电网调节。粗线长的距离,因为通过调节器的作用,线电流流过串联电容的电压所产生的相位滞后上升来实现。因此,较重的负载线,功率因数越低,稳压器系列电容补偿更加显着的作用。该稳压器的作用,随负载变化,具有自我调节的功能。