In order to avoid shedding generators when power system are subject to severe faults, TCSC and SVC can help greatly to improve system ability in maintaining synchronism. An energy function based control strategy for TCSC and SVC in multi-machine system is adopted. It is demonstrated in the paper that not only the angle stability can be improved by the proposed strategy, but also robustness to the variations of network topology can be obtained in certain cases. The effect of TCSC and SVC to improve transient stability of a typical high-voltage and long-distance AC transmission system is verified under all kinds of severe faults by simulation work carried out by the NETOMAC software. At the same time some supplementary stability-enhancing methods are considered and studied.

This paper develops an approach for optimal selection of signal-adapted wavelet in de-noising. The new method employs Wu's elimination algorithm to construct compacted orthogonal wavelets. The threshold cost function is used as the objective function during choosing of the wavelet. The approach is validated by its application to denoising for on-line partial discharge (PD) measurement. The physical experiments and field tests show that the method improves the suppression of noise for on-line PD measurement with stronger robustness. Copyright (C) 2004 John Wiley Sons, Ltd.

For the Yang Cheng-Huai Yin long distance transmission project of China,it's considered to replace current Fixed Series Compensation (FSC) with Thyristor Controlled Series Compensation (TCSC) based on the energy function control strategy for the transient stability enhancement of the power system.This paper first validates the proposed control strategy with NETOMAC program and compares the results with those of the physical experiment.Then,the simulation results of the simplified East China power network of 2005 are presented.All the results indicate that the probability of generator shedding is obviously reduced and the transient stability is greatly improved when FSC is updated to TCSC.Therefore,this research work is of significant engineering value.

A new type of petersen-coil automatic compensation equipment suitable for6～6kV power distribution network is presented.The principle and steady state operation performance of Thyristor-Controlled Reactor(TCR)is emphasized,including the adjustment characteristics of funda-mental frequency inductance,adjustable scope of firing angles of TCR,displacement voltage at neu-ral point ,and V-I characteristics etc.An example is given and validated by EMTP simulation.The results show that the presented design is reasonable and feasible.

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.

This paper presents a sampled regulator design method (SRDM) for TCSC and SVC control for the transient stability enhancement of long-distance transmission systems, when the accurate network topology and parameters are so difficult to be obtained that the parametric models of FACT and validity can not be implemented. The SRDM can guarantee control system stability, optimality and robustness, and only require knowledge of the open-loop system step response. i.e. a nonparametric model, which is particularly attractive for applications in power systems. The effectiveness of the proposed control design scheme is validated with the Yangcheng-Huaiyin transmission project of China, where the simulations are carried out by the NETOMAC program system.

介绍了一种可控硅调节的消弧线圈电抗器装置, 并着重研究适用于6～66 kV配电网的消弧线圈自动跟踪补偿装置中的可控硅调节电抗器的工作原理及其暂态性能.其中主要分析了突然投入理想正弦电源和接入电网中性点后电抗器本身的暂态响应及在稳定电源下工作点的调节,同时重点研究了在发生单相金属接地、单相高阻接地和间歇电弧接地情况下可控硅调节电抗器补偿容性电流的能力.通过实例进行EMTP仿真证明, 新型可控硅调节的消弧线圈电抗器装置在适当的控制策略下,其电磁暂态过渡时间是满足要求的,从而说明了该方案的有效性和可行性.

This paper presented a coordinated controller of thyristor controlled series compansator (TCSC) and static var compensator (SVC) for the transient stability enhancement of long transmission systems when the control interaction of the two FACTS devices is considered, according to the projective control theory. The developed scheme coordinates two measurement signals to control the TCSC and SVC, and was simulated in the Yangcheng-Huaiyin transmission project of China and compared to the FACTS controller scheme designed individually. The results show that the coordinated controller has better performance for the transient stability enhancement. In addition, by using equivalent injected currents models to simulate TCSC and SVC no modification of the bus admittance matrix is required at each iteration.

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.

Considering the sudden changes of current or/and voltage in a composite power system due to the switching on and off of FACTS devices in the system, this paper presents a detailed dynamic model of the modulation process of the static var compensator (SVC). Poincare mapping is employed to analyze the dynamic stability of the system, and the automatic differentiation technology is introduced to compute the Jacobian matrix of the Poincare mapping. Furthermore, the averaged model based on the Floquet theory is established and compared with the dynamic model proposed in the paper. The simulation results show the validity of the proposed method. This paper provides a new way for the further study of small signal stability, sub-synchronous oscillations, and transient stability of the composite power system.

With the abrupt change characteristics of current or/and voltage in a composite power system containing FACTS elements during the process of switch-on or off, the paper presents the dynamic modeling of the static VAr compensator (SVC) and generator. Then the Poincare map is employed to analyze the dynamic stability of the system; also the automatic differentiation technology is introduced to compute the Jacobian of the Poincare map model. Meanwhile, the averaged model based on Floquet theory is established and compared to. The simulation result validates the presented methods. Therefore, a new study method is provided to study further the small signal stability, sub-synchronous oscillation and even the transient stability in a composite power system.

现场总线控制系统作为新一代控制系统在电力系统尤其是在配电网自动化和变电站自动化中得到了广泛的应用.文中介绍了现场总线中一种很有影响的控制局域网络(Control Area Network,CAN)总线技术,同时介绍了嵌入式计算机的工业标准PC/104总线,设计出可用于变电站监控的基于CAN总线的嵌入式控制系统,并已在动态模拟实验室中投入运行,取得了满意效果.

The paper describes an exact linearization technique for multi input power systems with nonlinear loads. The nonlinear differential algebraic systems (NDAS) considered are not in general state variable form. The definitions of M derivative and M bracket similar to the definitions in classic differential geometric theory and some related revised results are given. M derivative and M bracket are used to obtain the feedback control law for the NDAS. The approach is used to design a nonlinear controller of SVC in single-machine infinite system with nonlinear loads. The simulation result shows that the nonlinear controller of SVC has better ability to improve the damping and voltage level than the conventional PID controller. Furthermore, the control law is even superior when the nonlinear loads vary.

In view of the tracking of general formal multi-input and multi-output (MIMO) nonlinear differential algebraic systems (NDAS) and the unccrtaintics of systemic parameters. The concept and definition of M derivative and M bracket based on differential algebraic systems, the normal form of differential algebraic systemic model is obtained by MIMO feedback linearization technology when systemic relative degree is less than systemic dimension and the some designated conditions are satisfied. In the light of the control theory of linear system and the requirements of tracking goal, the expression of general nonlinear control law is derived. Since the indeterminateness or uncertainty of parameters in practical systems, the nonlinear feedback control laws are pre-constructed quite difficultly to pledge the stability of whole systems, so that the suited parametric adaptive method are used to estimate and revise unknown uncertain parameter values by the theoretical method of Lyapunov stability, which realize nicely the control purpose of systemic tracking.

提出用于6～66 kV配电网的消弧线圈自动跟踪补偿装置中的可控硅调节电抗器参数设计的准则;即具有良好的基频运行特性和最佳的滤波效益(满足一次绕组电流的正弦波畸变率不超过允许值).根据这两个指标对一、二绕组间漏感和三绕组中的滤波器设计进行了详细分析,指出设计三绕组的滤波器主要是对3次谐波有较好的滤波性能.通过EMTP仿真对设计方案的有效性进行了验证.仿真结果表明,所提的设计准则是正确的,它能够对实际装置的开发提供理论依据.但在参数精确设计中,还需认真地考虑电网谐波阻抗、等效频率偏差、偏振电感值、电阻、谐波指标、使用环境和经济成本等众多现实因素.

The paper descries an approach of exact linearization for multi-input power systems with nonlinear loads. The considered nonlinear differential algebraic systems (NDAS) are not in general state variable form. Some new definitions of M derivative and M bracket that are similar to the definitions of classic differential geometric theory and some related revised results are given. The definitions of M derivative and M bracket can be easily used to obtain the feedback control law of the NDAS. The conditions of exact feedback linearization are shown. When given NDAS satisfy the proper conditions of exact linearization, the multi-machine power systems with nonlinear loads can be transformed into Brunovsky standard form with constraint algebraic equations.

The generator angle of each unit in a power system is obtained by using GPS synchronized clock, the transient stability is then predicted using time-series method, which is on line corrected by fuzzy controller real timely to determine the power network transient stability. Because all parameters are calculated based on the real time sampling data, they can accurately reflect the rapidly changing network structure and load. The calculation example on 22 nodes of 6 units shows that it can effectively predict the first swing transient stability with a higher predict precision under satisfied calculation speed.

This paper presents a transient stability prediction method inwhich a fuzzy neural network can, on the basis of GPS synchronized generator angles, predict whether the power systems is stable or not after large disturbances. This approach has fully exploited the advantages of fuzzy logic and neural network, i.e., integrating the expert's experience, learning from the sample set, extracting automatically the fuzzy rules and optimizing the membership functions, etc. Therefore, it has high accuracy of pattern recognition and function approximation. The simulation indicates the validity of the proposed method of transient stability prediction.

根据负荷的增长及电源规划确定合理的电网结构将是电网规划面临的长期的艰巨的任务.就电网规划的特点、面临的问题以及己有的方法进行了综述,指出在计及不确定性因素的的影响方面还需要进行更加深入地研究.

为适应电力企业市场化和管理现代化的需要,设计了基于多层Client/Server体系结构的地区电网运行管理系统,其先进的设计思想和采用最新的计算机技术保证了系统的较好性能,文章介绍了系统的设计方案和主要功能,并提出了本系统今后的发展方向.