基于原–对偶内点法的复杂电力系统电压崩溃校正控制

给出了在采用原–对偶内点法进行校正控制计算时值得注意的初值选取、中心参数选取等一些问题,并针对福建省网168节点系统的实际数据进行了仿真计算。结果表明,在考虑了这些要点后所求得的结果可靠,能较好地满足实际工程要求。     

高温管道复合型保温经济厚度计算方法的探讨

对大型火力发电厂高温汽水管道复合型保温材料经济厚度选取的3种计算方法进行了说明，以宝鸡第二发电厂的高温汽水管道为例，对3种计算方法进行了实际比较，从数学原理分析和实际举例结果中说明“双层经济厚度计算法”的优点。     

计及UPFC的电力系统双线性抗差估计

统一潮流控制器（unified power flow controller ，UPFC）作为柔性交流输电系统（flexible AC transmission systems，FACTS）的重要组件之一，对电力系统安全稳定运行起着重要的作用，而对含有UPFC的电力系统进行有效的状态估计也是电力系统电力电子化的必然要求。对UPFC模型进行抗差状态估计虽然能够有效抑制坏数据，但是存在模型复杂，计算效率低等问题。文章基于新型UPFC拓扑模型，采用双线性方法对含该UPFC的电力系统进行抗差状态估计。该方法通过选取有效的中间变量，对电力系统和UPFC组件的非线性量测方程进行分步线性化处理，在保证计算结果误差水平处在同一量级，能够工程应用的前提下，有效提高了状态估计的计算效率。对修改后的IEEE标准系统和南京西环网实际系统进行仿真测试，通过与WLAV测试结果对比，在保证相应精度的前提下，获得接近加权最小二乘法（weighted least squares，WLS）的计算速度，验证了本文方法的有效性和实用性。     

核电站设备可靠性数据库结构设计及数据源的确定

根据我国核电站的实际情况，进行了大亚湾核电站设备可靠性数据库的总体设计及数据源的确定，并对关键设备选取，设备累计运行时间计算，设备失效数据采集及甄别等问题进行了进一步探讨。     

银川地区10 kV配电网合环电流及计算方法的研究

在对10kv配电网合环稳态电流及冲击电流理论分析的基础上，结合银川地区配电网实际情况提出了基于PAS（电网高级应用软件）的合环稳态电流计算方法。该方法简单，易于实时计算，为调度员进行合理的合环操作提供了理论指导，提高了合环操作的可靠性、安全性。     

不同发电机模型对暂态稳定计算的影响

以黑龙江省东部电网为例，对选用不同发电机模型组合进行暂态稳定计算所得的结果进行了对比分析，从而指出了E’恒定模型和E’q恒定模型在实际应用中的局限性，并尝试性地提出了积分步长的选取对使用精确模型极为重要的观点。     

黄土地区的小流域产沙计算

根据黄土地区小流域泥沙概念性模型，选取黄河中游的三个小流域，分别运用分时段和以次洪为单位的方法进行了产沙计算，总体效果良好。表明了模型结构简单、概念明确、便于应用，可以在实际工作中采用。     

利用FLAC3D对山西某电厂单桩静载试验模拟

利用大型有限差分软件FLAC3D对山西某火电厂地基单桩竖向抗压静载试验过程进行模拟,其中,建模、边界条件选取、参数选取计算、桩土接触面参数计算选取是决定模拟效果的关键因素。充分利用软件特点与实际静载试验,选取合理参数进行实际模拟,并和实际静载试验过程及结果进行对比研究。对比研究表明,只要其参数选取合理,则FLAC3D模拟结果的准确性、适用性都明显增加。     

TDX-200透射电镜照明系统的计算与仿真

透射电子显微镜(transmission electron microscopy,TEM)的照明系统包括电子枪和聚光镜,它要求能提供最大亮度的电子束,照射在样品上的电子束孔径角必须能在一定范围内调节,照明斑点的大小可按需要选择。在调试过程中需要预先对照明系统激励参数进行计算。基于TDX-200透射电子显微镜,对双聚光镜照明系统的功能实现进行了理论分析,结合实际尺寸进行了理论计算与实际仿真,并在实际调试过程中进行了初步验证。     

基于地理信息系统的架空输电线路应力弧垂管理

为提高输电线路运行维护的信息化水平，在输电线路地理信息系统中增加了应力弧垂误差自动判定模块。探讨了应力弧垂误差自动判定的原理和过程，重点阐述了地理信息系统中属性数据与图形数据的关联、有效临界档距的确定和输电线路状态方程式的解法。该模块根据选取的地图信息，利用回调技术实现系统的图形数据和属性数据的连接，得到待测线路的设计条件，计算出标准弧垂，与实际观测计算得到的实际弧垂进行比较，并根据给定的误差值判断出弧垂是否在安全范围内。     

考虑输电线路动态增容的增强型安全约束最优潮流

在复杂内外部风险的影响下,输变电设备的随机故障已成为影响电网安全运行的重要因素。针对现有安全约束最优潮流存在的灵活性或安全性不足的问题,提出了一种增强型安全约束最优潮流(ESCOPF)模型,采用输电线路动态增容技术,保证电网在预想事故发生后至校正控制生效前的运行安全性。并给出了一种基于Benders分解的求解算法,将原问题分解为预防控制主问题、动态增容校验子问题和校正控制可行性校验子问题。通过不断向主问题返回Benders割修正机组发电计划,最终得到满足所有子问题校验的最优发电计划。算例分析结果表明,ESCOPF模型能够充分利用线路输电能力,扩大电网安全运行范围,从而提升系统运行的经济性。     

电力系统静态安全混合控制方法

提出一种将预防控制和校正控制相协调的电力系统静态安全混合控制方法。预防控制模块中,利用风险指标确定进入预防控制模块的预想故障集,该风险指标考虑了预想故障发生的概率及其严重性,采用连续线性规划技术求解考虑多预想故障的静态安全预防控制策略。校正控制模块中,首先判断系统静态安全裕度是否满足要求,并考虑风电/光伏的随机波动特性,针对不安全故障分别制定校正控制策略。所提方法通过系统风险指标协调预防控制和校正控制中考虑的预想故障集,从而将预防控制和校正控制相互协调,以获得安全性和经济性均满足系统需求的静态安全控制策略。以我国某682节点系统的算例验证了所提方法的有效性。     

Corrective switching algorithm for relieving overloads and voltage violations

It is widely known that corrective switching, including transmission line switching, bus-bar switching, and shunt element switching, may change the states of the power systems, and consequently, affect the distribution of power flows, transmission losses, short circuit currents, voltage profiles as well as transient stability of power systems. In this paper, a new algorithm is developed to find the best line and bus-bar switching action for relieving overloads and voltage violations caused by system contingencies based on a sparse inverse technique and fast decoupled power flow with limited iteration count. A general model of bus-bar switching action is also presented such that the new algorithm can simulate any kind of complicated bus-bar switching action. Furthermore, on the basis of a newly proposed voltage distribution factor by multiple iterations in power flow calculation, a novel algorithm for corrective voltage control by shunt switching is developed. These two algorithms are then integrated into a corrective switching algorithm. Simulation results on the WECC 179-bus system indicate that the new corrective switching algorithm proposed in this paper can effectively solve certain problems of line overloads and voltage violations. The computation time required is also satisfactory.     

考虑柔性交流输电系统设备控制的校正型安全约束最优潮流

为提升安全约束最优潮流调度的经济性与安全性,提出一种基于直流潮流的考虑柔性交流输电系统(FACTS)设备控制的校正型安全约束最优潮流模型。在线路故障发生后,通过FACTS设备校正措施,将线路潮流控制在其容许范围内。由于所提模型为大规模的非凸、非线性优化问题,难以直接求解,因此先采用大M法,将原非线性优化模型转换为混合整数线性规化模型,并采用Benders分解算法将转换后的模型分解为基态最优潮流主问题与N-1故障校验子问题。通过固定整数变量的方法,将非凸的混合整数优化子问题转换为线性规划子问题,从而能向主问题返回对应的Benders割。6节点系统与IEEE RTS-79节点系统算例验证了所提模型与算法的有效性。结果表明,考虑FACTS设备校正控制的安全约束最优潮流能有效提升调度运行的经济性。     

Power system state scheduling with the two-stage problem

Traditional statements of optimization problems in power system state scheduling lead to complexities at the on-line correction of variables. This paper considers a stochastic optimization problem with corrective functions of the given analytical type. The problem solution gives scheduled values of the state variables and the adjustment coefficients for corrective functions. The corrective functions represent a response of the control system to the unforeseen deviations in operation conditions. The preliminarily obtained coefficients of corrective functions allow a very easy and quick organization of the on-line optimal state correction. Dual variables of the optimization task can be corrected as well for fast spot price adjustment. A case study demonstrating the efficiency of state control using the suggested approach is considered     

Preventive/corrective control for voltage stability using directinterior point method

This paper describes the applications of the interior point (IP) method on preventive/corrective control (PCC) for voltage stability. The mathematical model of preventive/corrective control, based on the control costs, is proposed. In the real time mode, the preventive control is carried out when the voltage stability margins between the operating point and the stability boundary are too small. In the study mode, the corrective control is carried out when the voltage is insecure. After preventive/corrective control, not only should the system operation point be in the voltage secure area, but some voltage stability margins should also be maintained. The approach proposed has been successfully tested on five systems-from 100 bus system to 4000 bus system     

基于分布鲁棒优化的含风电系统静态安全校正控制方法

提出一种计及风电出力不确定性的电力系统静态安全校正控制方法。考虑与风电预测方法的合理对接,采用风电预测出力的区间及期望值信息描述风电的不确定性。以调整措施耗费的经济成本最小为目标,考虑发电机出力调整和切负荷2种控制措施,建立考虑风电波动的有功安全校正控制模型。基于分布鲁棒线性优化理论,将含有不确定性参数的校正控制模型转化为仅含确定性参数的鲁棒对等模型,并采用线性规划方法进行求解。某区域电网算例结果表明,所提模型得到的校正控制方案能够应对各种可能的风电波动;同时,该模型可实现控制策略经济性与鲁棒性的相互转化,并能给出控制策略鲁棒性程度的概率评价。     

高度测量过程的控制和实施

通过对高度测量过程的识别、策划、设计以及测量不确定度的分析,论述了高度测量实施和控制的全过程,指出确保测量过程是在要求的不确定度限值之内进行,通过实施监视确保迅速检测出存在的问题并及时采取纠正措施,防止出现错误的测量结果。     

Stability-based minimization of load shedding in weakly interconnected systems for real-time applications

The transient stability of power systems is highly affected by the changes in the power generation and load levels. Due to the variability of the generating resources, the system stability can be provoked and the system stability limits can be reached as a result of certain sudden drop in the power generation. In these cases, the load shedding can act as an effective emergency corrective action for keeping system stability; however, over-shedding of loads results in severe economical as well as social security problems. Therefore, minimization of the load shedding required for the restoration of the system stability is one of the main objectives of this paper. Another critical issue related to successful load shedding is the fast assessment of the system stability, and the amount of the load shedding as well as the implementation of the load shedding corrective action. Therefore, this paper presents a fast method of stability assessment and load shedding requirements in the weakly interconnected power system. The method is an improved form of the extended equal area criterion (EEAC) where the required system equivalence is based on the availability of wide area monitoring (WAM) devices in modern power systems. The paper also investigates the impact of the implementation duration of the required load shedding. The results are verified through time domain simulations which confirm the accuracy of the presented method and its suitability for real-time applications.