针对太阳能、光伏等新能源并网容量逐年增加带来电网电压波动等电能质量问题,研究了一种采用模糊PI控制的蓄电池储能型动态电压恢复器.利用蓄电池储能充放电性能高、电荷储存稳定及使用寿命长等优良性能,在电网电压波动时动态电压恢复器能够迅速提供稳定和高质量电压进行补偿.同时,为了提升系统的控制性能,在常用的双闭环控制策略基础上,将模糊控制算法应用于外环电压PI调节器,实现对影响系统控制效果的外环电压PI调节器进行参数自整定,然后配合空间电压矢量调制实现控制.最后,通过在MATLAB/Simulink软件中搭建了采用模糊PI控制的蓄电池储能型动态电压恢复器的微电网系统模型并进行仿真实验验证,结果表明,采用模糊PI控制的蓄电池储能型动态电压恢复器能够补偿出现电压跌落的微电网,并且具有较强的动态响应能力和抗扰能力.

控制性能标准指标(CPS)是评估区域电网调频能力的重要指标.通过分析电力系统中的因果关系,从理论上对造成CPS指标越限的根本原因进行了分析.通过尝试使用数据挖掘工具,从自动发电控制(AGC)机组投运情况方面进行分析,为改善CPS指标提出建议.

Analyses of the inverse and forward positions of a 3-DOF parallel mechanism (PM) along with two rotational DOFs and one translational DOF are presented in this paper. The module of this 2-PRU-PRRU PM is created, and the Jacobian of the 2-PRU-PRRU PM is derived. Boundary, local, and combined singularities are identified based on the Jacobian. The workspace of the 2-PRU-PRRU PM is discussed according to the singularities and condition of a U-joint interference. The 2-PRU-PRRU PM has a simple structure and supplements the 3-DOF PM family with two rotational DOFs and one translational DOF. The 2-PRU-PRRU PM can be applied in the fields of industrial assembly robots, motion simulators, coordinate measuring machines, and parallel machine tools etc.

Nanosheet-assembled ZnO flake-like ensembles were fabricated by a facile solution-based route. The morphology, size and micro/nanostructure of the ZnO flake-like ensembles were investigated in detail. X-ray diffraction and scanning electron microscopy indicated that all the ZnO flake-like ensembles with the porous features were composed of many nanosheets with a hexagonal wurtzite structure. After visible-light irradiation for 3 h, the as-obtained ZnO flake-like ensembles exhibited significantly high photocatalytic activity for decomposing malachite green, and the decomposition efficiency was 76.8%. All of which indicates that the ZnO flake-like ensembles could serve as a good candidate for the degradation of organic pollutants.

With the development of power grid,the energy-conservation based dispatch(ECBD) has become an irresistible trend;therefore,it's very meaningful to analyze the impacts due to the ECBD on the security and stability of Shanghai power grid.In this paper,the ECBD model is presented and applied to the Shanghai power grid.According to the fact that Shanghai power grid is a large receiving-end system,this paper studies the impact of ECBD on Shanghai power grid from several aspects,such as N-1 check,static voltage stability and transient voltage stability and so on.In addition,this paper also finds out the weak areas in Shanghai power grid after ECBD,and the faults which may cause transient voltage instability.The results are very useful for the implementation of ECBD in Shanghai power grid and ensuring the security and stability of Shanghai power grid.

To meet the demand of high stability, high quality, and low losses of power systems, the advanced energy management system (AEMS) is established and revealed in this bulletin, which has been put into trial operation in Shanghai power system for almost half a year. The AEMS is novel from all aspects covering idea, theory, method, software, and engineering. The essence of AEMS is exercising the hybrid automatic control theory and technology to realize multi-objective optimal closed-loop control of power systems. Based on an “event-driven” strategy, the AEMS transforms multi-objective optimal control problems into event identification and elimination by defining the unsatisfactory states of a power system as events. This bulletin concisely presents the theory and main advantages of AEMS, as well as its implementation in Shanghai power system.

上海长兴电网2008年7月2日发生了由于两回联络线故障跳闸引起与崇明电网解列的事故,事故过程中所有低周低压减载装置都未动作,事故后长兴电网频率和电压快速下降,最终电厂的低压解列装置动作后,小系统稳住运行.通过研究故障过程中的频率和电压特性,结合装置的动作原理和定值,对装置的动作行为进行了分析,并对如何巩固和提升上海电网的第三道防线提出了建议.

为了满足我国电力系统高稳定性、高电能质量和高经济性运行的需求,提出了Advanced-EMS,简称AEMS（先进电能管理系统）,已投入上海电网试运行为时半年.这是从理念、理论、方法、技术到工程实施的系统性的创新成果.其核心内容是用一种新的混成自动控制理论和技术来实现电力系统多重目标趋优闭环自动控制.该系统以"事件驱动"为内核,通过将不满意状态定义为事件,将趋优化问题转化为事件的处理和消除问题.本快讯概述了AEMS的理论要点及主要优点,并通报了AEMS在上海电网工程实现的情况.

电网黑启动过程中,经常会遇到启动大功率异步电动机的情况,威胁黑启动初始阶段小系统的稳定运行,上海电网黑启动方案必须解决燃机启动电源的配置问题。文章针对上海电网黑启动试验中出现黑启动初始阶段,在小系统空载运行的情况下,由于逆功率保护而往往发生机组并车失败的关键技术问题。利用RTDS实时仿真系统,结合调研结果,针对这些问题进行了专题研究。提出了系统空载运行机组并车失败的原因,确定电压下降是影响小系统安全运行的最主要因素,介绍了相应的解决方案,以确保电网一旦崩溃时黑启动预案的正常实施。并在燃机启动电动机负载特性试验的基础上,利用电动机启动瞬间的等值电路,提出了启动电源容量选择的方法,分析了影响启动容量选择的相关因素,并计算了闸电燃机的启动电源容量。

上海电网是一个大的受端电网,随着用电负荷的增长和网架结构的不断变化,上海电网电压稳定等问题将日益突出。文章针对受端电网无功电压方面存在的问题及特点,提出了如何开展电网无功电压控制、无功电压分析管理、无功设备配置等方面的全过程管理设想和建议。

先进的能量管理系统(AEMS)是基于混成自动控制理论,对网内各种资源进行统一、自动、科学调控,实现电力系统多重目标趋优控制的自动化系统.它以"事件驱动"为其内核,通过将不满意状态定义为事件,将趋优化问题转化为事件的处理和消除问题.文章介绍了上海电网AEMS系统建设,包括主站、发电厂端子站和变电站端子站三部分.AEMS主站包含混成自动电压控制系统(HAVC)、混成自动发电控制系统(HAGC)、混成自动抑制低频振荡控制系统(HADLFOC)以及混成自动稳定控制系统(HASC),发电厂子站将实现电压无功自动调控(AVC),变电站子站将AVQC功能实用化.上海电网AEMS系统将分三期建设,其中第1期已初步完成,调控对象为包括两厂两站,AEMS已从理论走向了工程应用.

The power margin index for Shanghai grid voltage stability is presented,and the time domain simulation checking method for the power margin index is discussed.PSASP-based time domain simulations show that the power system may display the interaction of voltage stability and transient power angle stability when the system operates at the limitation points of the PV curve.The influences of low-voltage release and load-cutting of the generator on voltage stability were simulated under the conditions that the system operates at its limit points and under other loads.

With the development of the 500 kV network in Shanghai and because of the limitation of short-circuit capacity, the districts such as Nanqiao, Yanggao, Xuhang and Gulu are bound to operate separately. The fault in 500 kV busbars and coupling transformers, the sudden lockout of the Three Gorges direct power and the sudden shutdown of the 900 MW units of Waigaoqiao No.2 Power Generation Co., Ltd. would probably result in the voltage instability in Shanghai Power Grid. The currently existing problems in voltage stability of Shanghai Power Grid were introduced and the feasibility suggestion on configuring dynamic reactive equipments was put forward and analyzed.

Under-frequency load shedding is an important and effective means to control common faults and large-scale complicated faults in power system. Cutting load correctly and quickly can make the whole system return to stable state in the shortest time, and the setting calculation of load cutting must be reasonable and precise to achieve the goal with minimal quantity of load cutting within shortest time. The proposed software package is composed of database foundation, data conversion and input, frequency computation and analysis, and load-cutting scheme optimization. The package can offer improved solution according to system parameters and regulation request, and it has convenient interface and easily-maintained and renewable database. Such superiorities are verified via the application and simulation in Shanghai power system.

针对上海西郊变电站±50 Mvar静止补偿器(STATCOM)接入系统的运行策略进行了研究和仿真.基于上海提供的电网数据,根据系统的实际情况,分析了上海西郊变电站±50 Mvar STATCOM的主要控制目标为动态电压支撑和日常调压.研究和制定了STATCOM接入系统的运行策略,对用于日常调压的无功容量进行限制,留有一定的动态无功备用,当出现快速和大幅的电压变化时迅速跳转至额定运行,以最大无功输出能力提供动态电压支撑.对±50 Mvar STATCOM与西郊变原有的两组30 Mvar投切电容之一相配合的综合运行方案进行了探讨,一般情况下该组30 Mvar电容一直投入,使STATCOM运行在感性输出范围内,这样可以增大电压降落时的动态无功备用.文中重点在电力系统分析综合程序(PSASP)中进行了仿真研究,仿真结果验证了运行策略的可行性和正确性.

Hop-hop protection mechanism is enough for inter-communication among the networks nodes. However, any node in the network can forge and send a packet with alleged original source. In this paper, we propose a new multicast model, called MAYA, for many-to-many group communication. The key idea of MAYA is to implement the mechanism of multi-domain certificate. By using MAYA mechanism, we can provide higher security for authentication and authorization.

上海电网随着负荷增长和网架结构的变化,电压问题日益突出,尤其是黄渡分区电网,缺少动态的电压支撑,不能满足电网安全运行的需要.文中将新型的动态无功补偿装置STATCOM应用于黄渡分区电网,进行了大量的仿真分析,并对不同的安装容量和安装地点进行了详细的比较分析.仿真结果表明,安装STATCOM装置将对黄渡分区电网电压起到较大的支撑作用.

受端电网缺少动态无功电源支撑,是导致电压崩溃的根本原因.通过吸取8·14美加大停电事故的教训,结合上海电网负荷和网架结构的特点,重点从上海电网分层分区运行和动、静态无功储备角度分析了上海电网的电压稳定问题,论证了上海电网配置动态无功装置的必要性与可行性,并从无功规划角度对提高上海电网电压稳定性提出了建议.

以上海电网2001年和2010年网架结构为背景,研究了静止无功补偿器(STATCOM)在上海电网中的应用前景,并利用德国西门子公司开发的电力系统软件NETOMAC对其进行仿真计算,比较了STAT-COM在2001年和2010年上海电网中对电压的动态支撑作用,从而为STATCOM在上海电网中的实际应用提供了计算依据.

Cascade STATCOM (Static Synchronous Compensator) has been widely studied because of its advantages over traditional STATCOM configurations. However, for deep research on cascade STATCOM, such as main circuit configurations, transient performance analysis, and control system design, a mathematical model is extremely needed. In this paper, by using a method of Fourier decomposition, a mathematical model describing dynamic characteristics of cascade STATCOM devices is presented. Based on it, the relationship between open-loop response time constant and the main circuit parameters of cascade STATCOM are analyzed. The proposed model is verified by digital simulations.