Modal reduced dynamic equivalent model for analog type power systemsimulator

Analog type power system simulators are playing important roles in cases where real time dynamic studies are required. Power system reductions are more important in analyses using an analog type simulator than a digital computer due to facilities limitations. This paper describes a modal reduced dynamic equivalent model which was developed for an analog type power system simulator to provide power system reductions. The model is implemented by using a modal analysis approach based on a digital type synchronous generator model. In simulator tests on a 28-machine power system, the model is judged to be useful for representing subsystems to be reduced in an analog type simulator     

The effect of load models on unstable low-frequency oscillationdamping in Taipower system experience w/wo power system stabilizers

This paper uses the eigenvalue analysis approach to observe the impact of load models on an unstable low frequency oscillation damping, which recently occurred in the Taiwan power system. In order to enhance oscillation damping, the effect of load models on power system stabilizers is also investigated. Three kinds of the derived load models (a dynamic model, a composite model, and an exponential model) based on the component approach with the measured characteristics of power system loads are used in this paper. Time simulation results are extensively used to verify the eigenvalue analysis results with and without power system stabilizers. One set of field test data obtained from the Taiwan power nuclear plant with power system stabilizers is used to determine which load model provides a more accurate result in enhancement of oscillation damping. Depending on the results, the effect of load models on electromechanical oscillation damping with and without power system stabilizers is verified     

Identification-based power unit model for load-frequency controlpurposes

This paper presents a new method for process transfer function identification (TFI) and a new approach for the development of a power unit's dynamic model based on new applications for presented TFI method. This method uses a two-stage procedure which indirectly reduces both noise effects and the order of the transfer function. The first stage is the frequency response identification of a process, while the second one is the transfer function computation using frequency response obtained in the first stage. The power unit dynamic model which is identified using three relatively simple experiments is applied to load-frequency control. This dynamic model developed for the vicinity of the steady-state operation mode can be used for automatic generation control purposes, to tune load-frequency control systems, as well as to build and set up a real-time simulator for dispatcher training. The modeling of 140 MW power units of the IEC (Israel) is fulfilled through implementation of this model and by its identification method yielding sufficiently good results     

新型注入式混合有源滤波器的数学模型及电流控制方法

有源滤波器的数学模型是进行稳态、动态及电流控制方法等方面研究的基础,本文以新型注入式混合有源滤波器为例,详尽分析了建立其数学模型的方法,结合双滞环电流控制方法响应速度快、开关损耗低的优点和递推积分PI控制方法无稳态误差的特点,提出了一种新的复合型电流控制方法.通过仿真,从跟踪速度、控制精度和开关次数三个方面,将新的控制方法与双滞环电流控制方法以及单一的递推积分PI控制方法进行了对比研究.实验结果也证明了该数学模型的正确性和复合型电流控制方法的有效性.     

利用多目标模糊动态规划法进行抽水蓄能电站的运行优化

本文论述了利用多目标模糊动态规划的方法来解决具有抽水蓄能电站的水、火电系统的短基运行规划问题，建立了考虑经济性和可靠性等多个目标的抽水蓄能电站在整个水火电系统中的运行优化模型，并用多目标模糊动态规划法处理这些目标。     

Hybrid simulation of power systems with SVC dynamic phasor model

A novel hybrid method for simulation of power systems equipped with static var compensators (SVC) is suggested in this paper, where dynamic phasor theory is applied for SVC, and traditional electromechanical transient models are used for ac subsystem. A detailed single-phase dynamic phasor-based SVC model is derived first, and an interface algorithm between the SVC dynamic phasor model and the ac subsystem is proposed next. Test results on the 9-bus and the New England 39-bus test power systems show clearly that the single-phase SVC dynamic phasor model has very good accuracy as compared with its electromagnetic transient model. The proposed hybrid-model simulation method provides a new approach for dynamic simulation of large-scale power systems including SVCs.     

统一潮流控制器的动态相量建模与仿真

为适应系统快速、精确仿真和分析、控制的需要，运用一种新的建模方法——基于时变傅里叶级数的动态相量法对统一潮流控制器(UPFC)进行建模和仿真。该方法通过忽略系统状态变量所对应的傅里叶级数中那些不重要的项而对原系统进行简化，并且可以有效地将系统中的连续事件和离散开关事件结合起来。在建模过程中可以根据研究需要提取出UPFC暂态模型中的直流分量和需要考虑的各次交流谐波分量。通过与详细时域模型仿真计算结果的比较，证明了UPFC的动态相量模型是精确而有效的，并且可以大大节省计算时间。     

Low-order dynamic equivalent estimation of power systems using data of phasor measurement units

This paper utilizes data measured by phasor measurement units (PMUs) to extract a low-order dynamic equivalent model for power system stability studies. The estimated model is a 2-order model for synchronous machines. This model has the advantage of simplicity of classical model and considerably reduces the oversimplifying error of classical model. This method offers an alternative approach to analytical model reduction techniques based on the detailed system models. The proposed method uses the synchronized bus voltage and current phasors measured by PMUs. Using post disturbance data, electrical and mechanical parameters of the equivalent generator are estimated sequentially. Furthermore, a new approach for estimation of two-machine and single machine infinite bus (SMIB) equivalent systems are presented for analysis of electromechanical oscillations. To evaluate the performance of the proposed approach, simulations are performed on a two area 13-bus test system and real measured PMU data. Simulation results show that the estimated model can represent the dynamic behavior of the studied system with good approximation.     

Hybrid-model transient stability simulation using dynamic phasors based HVDC system model

A novel hybrid-model transient stability simulation algorithm for ac/dc power systems is suggested in this paper, where dynamic phasors theory is applied for HVDC transmission system modeling, and traditional electromechanical transient models are used for ac system. A detailed dynamic-phasors-based HVDC system model is derived first, and the algorithm for interface of the dc dynamic phasors model to ac network is proposed next. Computer simulation results show that the HVDC dynamic phasors model has very good accuracy as compared with its electromagnetic transient model; the test results from a 2-area ac/dc power system and a multi-infeed HVDC power system show clearly that the suggested interface algorithm works effectively in system transient stability analysis. The proposed hybrid-model simulation algorithm provides a new approach for dynamic simulation of large-scale ac/dc power systems.     

STABLE AND REALIZABLE MODEL IDENTIFICATION FOR POWER SYSTEM DYNAMIC EQUIVALENT MODEL

Abstract

— This paper describes a new identification approach for dynamic modeling of three-phase power system and proposes methods for systematically determining the stable and realizable (SAR) model structure. A three-phase sample system was used to verify this approach and the results of simulation have shown that the obtained model can characterize the dynamics of the actual system accurately.     

基于纳什均衡理论的电力市场动态投标分析

为准确模拟电力市场参与者的动态决策过程,基于供给函数和纳什(Nash)均衡理论,考虑输电网固有的特性,提出计及输电网约束的电力市场动态供应函数模型。新模型由一差分动态系统和由非线性互补函数转换的半光滑方程系统构成,参与者策略报价的决策变量考虑为供应函数的线性和二次项系数。基于此两参数投标模型,以3个节点组成的电力市场为例,分析在不同市场参数和不同输电网运行状态(阻塞和不阻塞)下,市场的Nash均衡状况和均衡点的局部稳定性;通过数值仿真探讨不同市场参数对市场的动态行为及局部稳定性的影响;并与古诺(Cournot)模型进行仿真比较,仿真结果显示了供应函数模型更符合电力市场的运营情况。     

基于循环神经网络的动态等值模型辨识

为了在系统稳定计算分析中简化和减小计算难度,用动态等值作为一种建模方法提出了一种基于循环神经网络的电力系统动态等值法并结合串并联辨识结构将其用于等值后模型的辨识。这种方法不需要预先建立确定的动态模型,仅靠边界节点的测量数据。循环神经网络的权值和结构决定了被等值外部模型的参数和结构。对IEEE的39节点进行的仿真结果表明了该方法能够捕捉原始系统的动态特性,有较高的精确性。     

A generalized approach to the analysis of voltage stability in electric power systems

In this paper a new method for analysing the voltage stability problem in electric power systems is presented. The approach starts with a linearized model in state space form of a multi-machine power system, then rigorous voltage stability conditions are derived on the basis of a suitable aggregated model of the original system capable of retaining the dynamics of voltages at generator and load nodes.The approach allows a systematic individualization of all the dynamic factors which affect voltage instability phenomena and suggests the appropriate representation which has to be adopted for each dynamic component of the system.The validity and usefulness of the suggested method are illustrated by carrying out simulation studies on a sample power system.     

动态无功补偿改造探讨

本文就港口电力系统及大型电动装卸机械的动态无功补偿装置改造进行研究探讨。着重分析动力中心电站及单机上的静态无功补偿装置动态改造的方法、原理、效危分析，以及动态改造的可行性、必要性。     

广东电网基于BPA的实用负荷模型的建立与校验

在实际工程应用中,根据经验得到的静态模型或者固定负荷比例的综合模型已经不能满足各区域大电网的要求,文中提出了一种能够很好与BPA结合的实用负荷模型,采用了基于非对称故障的方法进行建模,用小生境免疫算法对模型进行优化辨识,并用仿真实例进行了验证与校核。最后将该模型应用于广东电网的建模研究中。仿真表明该实用负荷模型的不仅能与BPA结合,也解决了数据来源的问题,同时精度高、实用性强。     

Decentralised coordination of power system operation using dualevolutionary programming

This paper proposes a decentralised coordination framework for operating power systems with dispersed generation and energy storage. It then develops a novel decentralised approach for calculating the system optimal operation of resources with intertemporal links. The method combines elements of dynamic programming with evolutionary programming. Each power system resource evolves a 'future benefit' function that describes the impact of its own possible decisions on future power system operation. This 'dual evolutionary programming' approach can handle complex resource models and objective functions. It is shown to be computationally faster than discrete dynamic programming for a number of power system problems with multiple storage resources     

Using deep learning to combine static and dynamic power analyses of cryptographic circuits

Side-channel attacks have shown to be efficient tools in breaking cryptographic hardware. Many conventional algorithms have been proposed to perform side-channel attacks exploiting the dynamic power leakage. In recent years, with the development of processing technology, static power has emerged as a new potential source for side-channel leakage. Both types of power leakage have their advantages and disadvantages. In this work, we propose to use the deep neural network technique to combine the benefits of both static and dynamic power. This approach replaces the classifier in template attacks with our proposed long short-term memory network schemes. Hence, instead of deriving a specific probability density model for one particular type of power leakage, we gain the ability of combining different leakage sources using a structural algorithm. In this paper, we propose three schemes to combine the static and dynamic power leakage. The performance of these schemes is compared using simulated test circuits designed with a 45-nm library.     

Representation of a grid-tied microgrid as a reduced order entity for distribution system dynamics and stability studies

Microgrids comprising multiple distributed resources are being increasingly considered for integration into electricity networks. Considering the multiplicity of the distributed resources in a single location and distributed nature of such single entities, it is impractical to represent them as detailed models in power system simulations. Hence, it will be attractive for electricity utilities to employ simplified models of microgrids in dynamic studies. This paper proposes a method for representing grid-tied microgrids as simplified generator or load units in such studies. For this purpose, the paper takes an approach in investigating the applicability of modal analysis as a tool for model equivalencing of grid-tied microgrids with inverter and non-inverter interfaced distributed generators. Validity of the reduced order dynamic equivalents is tested under different operating conditions: power export and import modes, with different load types and fault conditions. Scalability of the model equivalencing approach is demonstrated using a case study developed based on the IEEE 13-Bus test feeder. Furthermore, the model equivalencing is applied on microgrids in a multi-microgrid environment to validate the methodology. The dynamic model equivalent of the microgrid can be represented as a current source at the point of common coupling while retaining all imperative dynamic characteristics. The proposed methodology is also applicable to distribution network clusters comprising distributed generators.     

弧焊电源的建模与仿真研究

采用状态空间平均法建立了全桥逆变式弧焊电源主回路的平均状态方程,经过线性化处理推导出频域小信号模型.并在MATLAB环境下,利用频域法分析主回路的动态性能,得到的仿真结果与实验结论相一致.对开关电源的理论分析和设计具有一定的参考价值.     

含风电系统的发用电一体化调度模型

在传统发电调度模式中融入用电调度,为风电等间歇性电源并网提供备用资源、保证电力平衡开辟了一条可行的途径.考虑融入用电激励、可中断负荷、电价响应等用电调度方式,建立了含风电系统的发用电一体化调度模型,采用启发式动态规划算法进行求解.算例分析表明,通过科学决策发用电资源调度,融入用电激励方式能够减少低谷时段风电弃风,提高了...