基于电压稳定的区域电网无功能力评价

区域电网无功能力作为电力网络安全运行的一个重要指标,直接关系到电力系统的经济性、安全性和可靠性。但目前研究主要集中在无功优化等方面,缺乏一种直接评价电网无功能力的方法。因此,结合静态能量函数提出了区域电网无功能力评估的新方法。首先,在保证电压稳定的情况下,通过内点法求出稳定运行状态情况下各节点参数以及在极限情况下的系统崩溃点数据,然后运用静态能量函数的思想获得各个运行状态下的能量函数值,最后建立表征区域电网无功能力的指标。阐述了新方法的应用背景和实现原理,并对IEEE-30 标准测试系统进行仿真分析,仿真结果证实了该方法的准确性和有效性。     

基于电压稳定的区域电网无功能力评价

区域电网无功能力作为电力网络安全运行的一个重要指标,直接关系到电力系统的经济性、安全性和可靠性.但目前研究主要集中在无功优化等方面,缺乏一种直接评价电网无功能力的方法.因此,结合静态能量函数提出了区域电网无功能力评估的新方法.首先,在保证电压稳定的情况下,通过内点法求出稳定运行状态情况下各节点参数以及在极限情况下的系统崩溃点数据,然后运用静态能量函数的思想获得各个运行状态下的能量函数值,最后建立表征区域电网无功能力的指标.阐述了新方法的应用背景和实现原理,并对IEEE-30 标准测试系统进行仿真分析,仿真结果证实了该方法的准确性和有效性.     

智能式动态无功补偿装置的研究

介绍了一种智能式动态无功补偿装置，分析了装置的工作原理，装置采和MOTOROLA单片机系统作为控制器的核心，从无功补偿的原理出发，建立了电容器自动补偿的最优控制方法，设计了控制器的软硬件，并且采用晶闸管无触点开关实现电容器组的快速自动投切，它通过检测晶闸管无触点开关（SCR）两端电压为零作为SCR触发的必务条件，具有硬件闭锁保护，避免了误触发造成的冲击电流损坏元件，并且不会产生无功倒送，实现了无功补偿装置的优化运行和高可靠性及自动化，有很强的现场控制能力和适应能力。     

Estimation of reactive power export and import capability fornon-utility generators

Non-utility generators (NUG's) are typically required by their electric power sales agreement to have the capability to supply power to the purchasing utility near unity power factor. With the advent of large combustion turbine generators, many NUG's are simple or combined cycle facilities with generating capacities in excess of 100 MW. Utilities are recognizing that these large NUG facilities can be significant contributors to the reactive power [megavars (MVArs)] flow needed to support system requirements and transmission level grid voltages. NUG's are now being dispatched for MVAr export and import activities to meet utility requirements. The ability of a NUG to export or import MVArs is highly dependent on the actual transmission intertie voltage level. Unless plant-specific studies are performed, this capacity can be difficult to ascertain for the NUG operating and engineering personnel. This paper presents a method, based on system load-flow studies, for estimating the capacity of a NUG to export or import MVArs at a given transmission intertie voltage level. It also explores other key variables which determine the ability of a NUG to export or import VArs. This methodology can be used to aid operating personnel at existing facilities or as a guide during the design of a new facility     

考虑柔性负荷无功调节能力的配网日前两阶段无功随机优化调度

针对高比例分布式光伏接入配网所引起的电压控制问题,利用柔性负荷的无功调节能力,并考虑光伏和负荷的不确定性,提出了配网日前两阶段无功随机优化调度方法。首先,在第1阶段根据光伏和负荷的预测值,优化反映电容器组动作和柔性负荷无功调度的离散决策变量。其次,在第2阶段考虑光伏和负荷的不确定性,优化光伏的无功出力和柔性负荷的无功调度量。在优化模型中,设置了电压偏差最小化和柔性负荷的无功调度次数最小化两种目标函数,采用ε约束法对多目标优化问题进行求解,并利用熵权优劣解距离(technique for order preference by similarity to ideal solution, TOPSIS)法选择最优折衷解。在修改的IEEE33节点系统进行仿真,结果表明所提方法能有效缓解由高比例分布式光伏并网所引起的电压越限问题。     

市区输电网无功电压集中闭环优化控制

市区输电网无功电压集中闭环优化控制可提高电网的电压质量和功率因数，降低系统的有功损耗，使电网电压和无功处于经济运行水平。以两套集控站主站为例，在现有调度自动化设备和集控站基础上，提出了系统的改造方案。阐述了此方案软件升级、硬件改造的原理。     

基于DSP谐波诊断和动态抑制无功补偿节能装置的设计

介绍了一种基于DSP的谐波诊断和动态抑制无功补偿节能装置。系统采用先进的定点DSP芯片TMS320LF2407作为控制器的核心 ,解决了抗泄漏效应和抗混叠效应两个关键技术 ,减少了FFT数据处理带来的误差 ,提高了系统的精度和准确度。系统实现了从信号采集到电容器组的无功补偿和LC滤波器的谐波抑制的快速自动投切功能 ,实践证明该系统运行具有高可靠性及快速动态响应性。     

Evaluation of wheeling and nonutility generation (NUG) optionsusing optimal power flows

The application of optimal power flow for the evaluation of wheeling and nonutility generation (NUG) related options is presented. Both wheeling and NUG options affect vital attributes such as system security, voltage profile, losses, and VAr reserves. These options put a strain on the existing transmission system and may restrict economic utility dispatching. Optimal power flows may be used to determine the best control settings to accommodate wheeling or NUG options so as to maintain system security while minimizing losses or production cost. Short-term marginal wheeling costs may be derived using optimal power flows. Case studies involving the Northeast Utilities and IEEE test systems are presented. These cases show that optimal power flows can be used effectively to address a broad range of wheeling or NUG related planning issues     

应用有功负荷曲线和无功补偿选择配电变压器容量

分析了按负荷曲线和无功补偿来选择配电变压器容量的特点,并对传统的按视在负荷容量选择配电变压器的方法作了简要分析.给出了依据负荷曲线和无功补偿来选择配电变压器的容量原理.重点阐述了依据负荷曲线和无功补偿来选择配电变压器的容量分析过程和有关技术参数的选择和配置问题.并对所选择的变压器过负荷能力进行了校验.依据负荷曲线和无功补偿选择出来的变压器容量,即能够满足正常工作需要,又能够满足过负荷的需要.     

应用有功负荷曲线和无功补偿选择配电变压器容量

分析了按负荷曲线和无功补偿来选择配电变压器容量的特点,并对传统的按视在负荷容量选择配电变压器的方法作了简要分析。给出了依据负荷曲线和无功补偿来选择配电变压器的容量原理。重点阐述了依据负荷曲线和无功补偿来选择配电变压器的容量分析过程和有关技术参数的选择和配置问题。并对所选择的变压器过负荷能力进行了校验。依据负荷曲线和无功补偿选择出来的变压器容量,即能够满足正常工作需要,又能够满足过负荷的需要。     

零功率装置的发电机组外送线路中断后超速保护方案

大型火力发电厂在输出通道突然中断的情况下,运行的机组将会发生超速,甚至造成损坏,为避免此类事故的发生,经过分析论证,考虑采用零功率装置方式进行切机,以确保机组设备的安全停运。     

考虑风电机无功调节能力的配电网有功 / 无功联合调度

针对含风电的配电网运行的研究大多只关注风电机输出的有功功率,而忽略其具有的无功输出能力。通过对双馈风电机组功率极限曲线的详细分析,建立考虑风速随机性的配电网有功/无功联合调度模型,该模型同时考虑调度方案的最优性和鲁棒性,并采用基于极限松弛的方法进行求解。仿真结果表明,所提方法可利用风电机的无功调节能力提高配电网电压稳定裕度,同时减少额外无功设备的投入,且所提方法获得的调度方案具有较高鲁棒性。     

提高双馈风电机组动态无功协调控制能力的实验研究

随着风电场规模不断增加,风电机组并网对电网的影响逐渐增大,故充分挖掘风电机组的无功电压调节能力和提高机组的无功响应速度对增强电力系统的电压稳定性具有重要作用。定量分析了蒙西电网某风电场单台双馈感应风力发电机(Doubly Fed Induction Generator, DFIG)的无功电压调节能力及限制因素,根据其单台机组的无功调节机理制定动态无功补偿协调控制策略。若系统无功需求超过DFIG无功出力极限时,在保证机组最大发电效益的基础上,提出基于无功差值的双馈感应风力发电机组有功附加控制。并且通过改进的遗传控制算法辨识得到附加控制器参数,该控制在降低机组最小出力的同时确保提高机组无功出力极限,进而满足系统无功需求。最后通过实验验证了所提出的双馈风电机组动态无功协调控制的可行性和准确性,增强了机组的电压稳定能力。     

An integrated control approach for standalone operation of a hybridised wind turbine generating system with maximum power extraction capability

This paper presents a novel configuration of a hybrid wind generating system which can be used as a remote area power supply (RAPS) system. The proposed wind energy conversion system consists of a doubly-fed induction generator (DFIG) and a permanent magnet synchronous generator (PMSG) where the latter is connected to the DC bus of the DFIG generator. In addition, a battery storage system is also incorporated into the DC bus to address the demand-generation mismatch. Control strategies for individual system components of the RAPS system are designed with a view to achieve an acceptable level of voltage and frequency regulation while extracting the maximum power from wind. The performance of the proposed RAPS system is investigated in terms of voltage and frequency regulation capability under changing wind and variable load conditions.     

Voltage security constrained active and reactive power pricing considering reactive market power

Reactive power support and voltage stability are considered to be very essential for preserving system security. This paper proposes a new market-based approach for voltage security constrained active and reactive power pricing. The problem is modeled as a multi-objective OPF in which the social welfare and the distance to voltage collapse point are maximized at same time. An important feature of the proposed approach is using the reactive market power index, Herfindahl–Hirschman Index (HHI), to assign optimal weighting factors of the multi-objective function. In addition, in this method not only the reactive power is considered but typical price is also provided based on real costs. The results show that the proposed method allows market operators and participants to preserve the level of security and social welfare within acceptable range by controlling the weighting factors and monitoring the HHI with regard to reactive market power. Using the proposed method and considering reactive power market, a suitable range of weighting factor can be determined ensuring the optimal bidding as well as satisfying the voltage security of the system.     

基于无功功率波动系数的无功功率考核方法

针对现行的均权平均功率因数考核方法不能反映用户无功功率负荷特性,不能对影响电能质量的用户加收改善电能质量的电费问题,提出了一种基于波动系数的无功功率考核方法。该方法通过动态无功补偿装置或专用的无功检测设备,记录无功功率的变化规律,根据设定的无功功率允许波动范围,将超出范围的不同时段无功功率波动陡度系数与幅度系数乘积的和定义为无功功率波动系数。采用与电费收费对应时段内无功功率波动系数与均权平均功率因数共同对用户的无功功率进行考核,促使用户主动改善电能质量,提高电能的使用效率。     

基于无功功率波动系数的无功功率考核方法

针对现行的均权平均功率因数考核方法不能反映用户无功功率负荷特性,不能对影响电能质量的用户加收改善电能质量的电费问题,提出了一种基于波动系数的无功功率考核方法.该方法通过动态无功补偿装置或专用的无功检测设备,记录无功功率的变化规律,根据设定的无功功率允许波动范围,将超出范围的不同时段无功功率波动陡度系数与幅度系数乘积的和定义为无功功率波动系数.采用与电费收费对应时段内无功功率波动系数与均权平均功率因数共同对用户的无功功率进行考核,促使用户主动改善电能质量,提高电能的使用效率.     

Security-constrained reactive power dispatch

A method of solving the preventive security-constrained reactive power VAr dispatch problem is presented. A decomposition-coordination scheme is conceived in order to take advantage of the special structure of the problem. Instead of tearing the network, the problem itself is decomposed into smaller subproblems. Techniques are presented for contingency simulation and for the handling of these contingencies in the optimization process. The computing procedure is given for the step-by-step solution for online implementation. VAr-oriented load flow and optimal power flow methods are described. Numerical testing results are reported     

我国电力工业和发电技术未来发展趋势

传统工业化走的是通过高消耗追求经济数量增长和先污染后治理的道路。介绍在传统工业化面临严重危机的背景下,可持续发展战略和新型工业化的兴起和特点,充分体现了未来发展的要求。在分析、总结世界能源发展的经验和规律的同时,对未来世界能源发展进行了宏观预测。以科学发展观为指导,采用未来学的方法,结合我国国情、发展现状和近中期发展目标,对本世纪特别是21世纪前20a我国电力工业和发电技术趋势进行了初步探讨,对国家能源安全等问题进行讨论。