基于系统留数矩阵的广域PSS设计

电力系统低频振荡严重影响电网的稳定运行。传统的电力系统稳定器（PSS）采用本地机组信号，不能有效提高系统阻尼。广域测量系统使得电力系统向广域观测与控制的方向发展。文中使用反馈信号机组和控制机组相分离的设计思想，提出根据转子角频率对振荡模式的能观度选取反馈信号机组，根据PSS输出信号对振荡模式的能控度选取控制机组，从而构成广域PSS控制回路。基于留数矩阵的分析表明了这种广域PSS控制策略具有比本地信号PSS更强的能观性和能控性。最后给出了基于留数的广域PSS参数设计方法。16机系统上的仿真结果表明，基于留数矩阵进行设计的广域PSS能更有效地抑制系统低频振荡，提高互联电网的稳定性。     

采用广域测量信号的互联电网区间阻尼控制

在大型互联电力系统中，区间模式的低频振荡是限制传输能力的严重瓶颈之一，而经典阻尼控制（如PSS）因限于局部测量不能很好地解决这个问题。迅速发展的广域测量系统能在全网范围内精确测量和高速传递机组相对功角和角频率等量，使得采用广域测量信号构成全局性的区间阻尼控制系统成为可能，进而为提高互联电网的功角稳定性和传输容量提供了契机。文中在一个简单的2区4机电力系统中，研究了采用广域测量信号实现励磁控制器区间阻尼控制环节的设计原理、实现方法和仿真效果，说明了基于广域测量系统的区间阻尼控制能有效抑制区间低频振荡和提高互联系统的传输容量，而且可工程实现。同时就设计适用于复杂电力系统的广域阻尼控制系统提出了一些关键性理论和实际问题，以供进一步深入研究。     

采用广域测量信号的互联电网区间阻尼控制

在大型互联电力系统中，区间模式的低频振荡是限制传输能力的严重瓶颈之一，而经典阻尼控制(如PSS)因限于局部测量不能很好地解决这个问题。迅速发展的广域测量系统能在全网范围内精确测量和高速传递机组相对功角和角频率等量，使得采用广域测量信号构成全局性的区间阻尼控制系统成为可能，进而为提高互联电网的功角稳定性和传输容量提供了契机。文中在一个简单的2区4机电力系统中，研究了采用广域测量信号实现励磁控制器区间阻尼控制环节的设计原理、实现方法和仿真效果，说明了基于广域测量系统的区间阻尼控制能有效抑制区间低频振荡和提高互联系统的传输容量，而且可工程实现。同时就设计适用于复杂电力系统的广域阻尼控制系统提出了一些关键性理论和实际问题，以供进一步深入研究。     

基于广域测量信息的互联电网模型预测阻尼控制北大核心

提出一种基于模型预测控制的新型阻尼控制器设计方法。为抑制区间低频振荡,该控制器由2级PSS构成,其输入信号由广域测量信号和本地测量信号组成。采用留数矩阵法选择广域控制回路,通过模式辨识进行2级PSS控制。将常规励磁系统中传统的自动电压调节器(automatic voltage regulator,AVR)用模型预测控制器(model predictive controller,MPC)替代,并与2级PSS协调作用,通过模型预测和优化求解,得到励磁控制器的最优控制输入,以实现电压调节和增强阻尼之间的动态协调。典型的四机两区系统仿真结果表明,基于模型预测控制的2级PSS设计的控制效果明显优于传统的阻尼控制,可以快速调节机端电压,显著改善互联电网阻尼。     

基于广域测量信息的互联电网模型预测阻尼控制

提出一种基于模型预测控制的新型阻尼控制器设计方法。为抑制区间低频振荡,该控制器由2级PSS构成,其输入信号由广域测量信号和本地测量信号组成。采用留数矩阵法选择广域控制回路,通过模式辨识进行2级PSS控制。将常规励磁系统中传统的自动电压调节器(automatic voltage regulator,AVR)用模型预测控制器(model predictive controller,MPC)替代,并与2级PSS协调作用,通过模型预测和优化求解,得到励磁控制器的最优控制输入,以实现电压调节和增强阻尼之间的动态协调。典型的四机两区系统仿真结果表明,基于模型预测控制的2级PSS设计的控制效果明显优于传统的阻尼控制,可以快速调节机端电压,显著改善互联电网阻尼。     

基于混合特征值灵敏度的广域PSS设计

为抑制互联电力系统的低频振荡,提出了基于混合特征值灵敏度的广域PSS设计方法。介绍了混合特征值灵敏度的概念,然后根据模式—机组的关联特性,采用反馈信号机组和控制机组相分离的设计思想,提出采用混合特征值灵敏度的幅值指标选取控制机组,根据模态等值选取广域反馈信号,最后根据特征值灵敏度的相角指标对两层式结构的广域PSS进行参数设计。IEEE39测试系统上的仿真结果表明,基于模式—机组关联特性的灵敏度指标设计的广域PSS能够有效抑制电力系统的区间低频振荡,提高互联系统的传输容量,提高系统的小信号稳定性。     

广域PSS附加阻尼控制的时滞分析及时滞补偿

通常基于本地反馈信息的电力系统稳定器(Power System Stabilizer,PSS)不能很好地抑制系统区间低频振荡,广域测量系统(Wide Area Measurement System,WAMS)的应用为抑制系统区间低频振荡提供了强有力的工具。提出一种考虑时延影响的PSS,并利用增益调节模块和相位超前/滞后模块构成PSS时滞补偿环节,消除远方信号延迟的影响。以一个四机两区域系统为例,利用改进矩阵束的方法辨识不同延迟条件下对阻尼控制的影响和阻尼补偿效果。仿真结果表明该时滞补偿方法在一定延迟范围内的有效性,维持了PSS采用远方信号的阻尼效果,提高了系统稳定性。     

采用广域反馈信号的电力系统稳定器投运条件

电力系统低频振荡阻尼控制是目前广域闭环控制的研究热点,其中采用广域反馈信号的电力系统稳定器(PSS)是主要控制方式之一。广域PSS的投运条件是运行人员主要关注的问题之一,但目前鲜有相关研究。文中以实际工程应用为背景,提出了广域PSS的"退出""投入"和"激活"3种运行状态及相互转换关系;同时提出了广域PSS的3个激活条件,包括本地功率、爬坡和频率条件,分别对应本地控制机组出力改变、非本地机组出力改变和非低频振荡频率的系统振荡3种特殊系统运行状态,以针对这些特殊状态确定广域PSS是否投运。随后的RTDS硬件在环测试结果表明,激活条件与运行状态切换相结合的广域PSS投运条件可有效保证其不起坏作用。广域PSS投运条件的研究及测试结果将为今后采用广域反馈信号的PSS在实际工程中的应用提供参考价值。     

考虑时滞影响的电力系统广域集中励磁控制

针对电力系统区间低频振荡问题，构建了广域集中励磁控制(wide-area centralized excitation control，WCEC)框架。在充分考虑时滞影响的前提下，根据时滞输出反馈鲁棒控制理论设计了WCEC。广域测量系统实时测量反映区间低频振荡的状态变量，并将其传送至WCEC进行计算分析，WCEC把全局控制信号传送给相关机组的励磁系统，以此阻尼电力系统区间低频振荡。4机2区域电力系统的频域分析和时域仿真表明，WCEC在较宽的时滞区间内提高了系统的阻尼值，能够快速有效地抑制区间低频振荡，并且具有对运行状况的鲁棒性和对时滞类型的不敏感性。     

采用广域测量信号的PSS参数优化设计

为了解决传统的电力系统稳定器PSS(Power System Stabilizer)因局限于反馈本地信号而不能很好地抑制区域模式的问题,针对区域模式装设引入广域测量信号的PSS,针对地区模式装设引入本地信号的PSS。根据参与因子确定PSS装设地点,然后应用遗传算法对其参数进行协调。由于PSS反馈远方信号,设计时考虑了通信延迟的影响。算例表明,提出的方案能够较好地抑制低频振荡。     

Slow-coherency based composite mode oscillatory stabilization bymeans of a hybrid PSS

The authors address the problem of the stabilization of composite mode electromechanical oscillations of electric generators. A hybrid PSS (power system stabilizer) with a two-level structure composed of a local PSS and a global PSS is proposed. A weighted combination of local and global control signals is used as the supplementary signal for the improvement of the damping characteristics of both local and interarea modes. Time-scale decomposition is applied to the decoupling of the local and interarea modes. Determination of the global control law is based upon a slow-coherency aggregated model     

Damping controller design for power system oscillations usingglobal signals

This paper describes a new power system stabilizer (PSS) design for damping power system oscillations focusing on interarea modes. The input to the PSS consists of two signals. The first signal is mainly to damp the local mode in the area where PSS is located using the generator rotor speed as an input signal. The second is an additional global signal for damping interarea modes. Two global signals are suggested; the tie-line active power and speed difference signals. The choice of PSS location, input signals and tuning is based on modal analysis and frequency response information. These two signals can also be used to enhance damping of interarea modes using SVC located in the middle of the transmission circuit connecting the two oscillating groups. The effectiveness and robustness of the new design are tested on a 19-generator system having characteristics and structure similar to the Western North American grid     

计及广域阻尼控制的PSS均匀通信时滞极限计算

为定量分析采用全局信号控制的电力系统稳定器（PSS）的时滞稳定性问题，利用扫频法对计及广域阻尼控制的2级PSS控制策略和PSS辅助区间阻尼控制进行数学建模，并计算出各自的时滞稳定极限，进而定量分析了时滞PSS系统的控制性能。算例验证了该方法的有效性和实用性。     

Fixed-order controller for reduced-order model for damping of power oscillation in wide area network

The interconnected power systems are complex and stabilizing control design still remains challenging task. The use of wide area monitoring system (WAMS) offers an integrated measurement-based and model-based control, which suits to the operation of large electric power system (EPS), along with online analysis. This paper presents a study on fixed-order controller design for equivalent network of coherent generator in order to stabilize inter-area electromechanical oscillations in the system. Firstly, the coherent generators in each area of large EPS are determined by mutual information theory, which represents the dynamic equivalence. Then network of each area with input–output variables of the selected generator that participates dominantly is reduced to lower size by square-root variant of balanced truncation algorithm. The dynamics and important oscillation modes are verified in equivalent representation of each area. Finally a local controller (decentralized) in each coherent area and a centralized controller between two coherent areas for selected generator are designed by reducing the H^∞ norm of its closed loop transfer function as much as possible. These controllers feed supplementary control signal in addition to one fed by local conventionally tuned PSS. The decentralized controller for selected generator is fed by local bus power or generator’s speed signal. On other hand, the centralized controller uses difference of power flow/speed of generators as input signal to dampen the oscillations between equivalent networks of two areas. The simulation results reveal effective damping of power/speed oscillations achieved by designed controller with respect to conventional PSS implemented. The robustness of controller is verified for heavy and light load operating conditions.     

Implementation of a hybrid power system stabilizer

Dynamic stability enhancement of composite mode oscillations of interconnected power systems by means of a hybrid power system stabilizer is discussed. The proposed hybrid PSS is of a two-level structure composed of a local mode and a global PSS inter-area mode damping. The input of the global stabilizer is the center of inertia speed deviation of slow-coherent generators. This work is mainly focused on the practical considerations in implementation of the proposed stabilizer. The optimum allocation of this stabilizer is discussed. An index of mode-input-assignability, by which the best sites of the stabilizer can be identified, is introduced. For practical applications, an estimation for the approximation of the input of the global PSS is introduced. An approximated value of the center of inertia speed is obtained from a suitable combination of the rotor speed data of a few properly selected key generators     

基于Prony方法的电力系统振荡模式分析及PSS参数设计

Prony分析是获取系统振荡模式的一种非常有效的分析方法,它可以通过给定输入信号下的响应直接估计系统的振荡频率、阻尼、幅值和相对相位。文章介绍了基于Prony分析的电力系统等值线性模型的辨识方法,对传统的Prony方法进一步扩充,考虑了输入信号对输出信号的影响,得到了系统的传递函数,并根据其相应留数,采用留数方法对电力系统稳定器(PSS)进行了参数的协调配置。两个算例的仿真结果证明了该方法在系统振荡模式分析和PSS参数设计中的有效性。     

Two-level optimal stabilization in multi-machine power systems

The control signals needed for the optimal stabilization of an interconnected multi-machine system are obtained using a two-level control strategy. At the lower level, local control signals are derived assuming no interaction between different machines. Then a global control signal is generated at a higher level to minimize the effect of interactions.Computer simulation of a real power system shows that the stability of the system may be enhanced substantially by adopting the two-level scheme. Response of the system with an integrated control scheme is included for comparative analysis.     

基于TMS320F28335的电力系统稳定器的研究

目前国内普遍采用以电功率作为输入信号的单输入电力系统稳定器（PSS）,然而在原动机功率发生变化时, PSS本身不能区分系统波动和原动机功率波动,容易引起“反调”。设计了一种基于TMS320F28335的双输入PSS,发电机的电功率和转子角速度作为该PSS的输入信号。论述了双输入PSS的模型,硬件设计部分主要包括总体结构的设计,软件设计部分包括总体设计及流程图。运用附加双输入PSS励磁调节器进行了阶跃和反调实验,结果表明该PSS能够有效抑制低频振荡,很好地解决“反调”问题。