非线性鲁棒电力系统稳定器NR-PSS在白山300MW水轮发电机组上的应用

利用非线性鲁棒控制理论研究的新一代大型发电机组非线性鲁棒电力系统稳定器NR-PSS在白山电厂300MW发电机组上投入运行.本文通过古典PSS(IEEE PSS2A)与NR-PSS的工业试验结果进行对比,验证了NR-PSS对于PID、PSS2A具有质的优越性.     

Robust PID control design for permanent magnet synchronous motor: A genetic approach

In this paper, a robust PID control scheme is proposed for the permanent magnet synchronous motor (PMSM) using a genetic searching approach. Genetic algorithms (GAs) are powerful searching algorithms based on the mechanics of natural selection and natural genetics. Based on a simple genetic algorithm, a set of PID parameters can be obtained such that the robust stability for the closed-loop system is guaranteed, the tracking performance is minimized subject to certain related cost function, and the disturbance rejection ability (H_∞ performance) subject to a prescribed attenuation level can also be achieved. Numerical solutions of the PID parameters constrained by three different objectives and simulation results are provided to illustrate the design procedure and the expected performances. Finally, the proposed PID control scheme for the PMSM is implemented by a DSP-based fully digital controller. From the experimental results, the performances can be achieved using the proposed PID control scheme. In opposition to trial and error, the PID parameters can be obtained systematically in this study. The proposed method is simple and is suitable for practical control design in the motor drive.     

Design of a nonlinear power system stabilizer using synergetic control theory

Electromechanical oscillations of small magnitude and low frequency exist in the interconnected power system and often persist for long periods of time. Power system stabilizers (PSSs) are traditionally used to provide damping torque for the synchronous generators to suppress the oscillations by generating supplementary control signals for the generator excitation system. Numerous techniques have previously been proposed to design PSSs but many of them are synthesized based on a linearized model. This paper presents a nonlinear power system stabilizer based on synergetic control theory. Synergetic synthesis of the PSS is based fully on a simplified nonlinear model of the power system. The dynamic characteristics of the proposed PSS are studied in a typical single-machine infinite-bus power system and compared with the cases with a conventional PSS and without a PSS. Simulation results show the proposed PSS is robust for such nonlinear dynamic system and achieves better performance than the conventional PSS in damping oscillations.     

基于LMI的μ方法及其在电力系统中的应用

对现有基于线性矩阵不等（LMI）的μ（结构奇异值，SSV）方法进行了优化，给出了基于大规模稀疏LMI算法的μ鲁棒控制器设计算法，并将μ方法应用于SMIB系统励磁控制的鲁棒稳定性分析和鲁棒控制器的设计，将其结果同经典的PSS控制器的结果做了比较，数值结果表明，所得μ控制器在追踪控制能力和鲁棒性等方面优于传统的AVR＋PSS控制方式。     

基于DSP的数字励磁调节器

目前广泛使用的同步发电机数字励磁调节器使用简单的单片机控制,采用PID(比例—积分—微分控制)+PSS(电力系统稳定器)控制策略,励磁调节器体积大,模块间干扰大,速度低、可靠性差,很难保证产品质量达到标准要求。为了弥补这个不足,采用PID(比例—积分—微分控制)+PSS(电力系统稳定器)+NOEC(非线性最优励磁控制)综合控制策略,把DSP(TMS320F2812)用于同步发电机数字励磁调节器中,具有通用性强、结构简单的特点,可以实现优良的控制效果。     

Decentralized nonlinear H∞ controller for large scale power systems

The aim of this paper is to design nonlinear decentralized controllers for multi-machine power systems. The design procedure is based on H_∞ control theory and consists of two parts. First, the feedback linearization technique is used. Then, a robust controller is designed using the linear matrix inequalities (LMI) approach. The controller has two blocks. One, is a nonlinear function of some local measurable signals such as the generator active and reactive powers, the rotor speed and the armature current. The other block is a PID controller. The linear H_∞ theory is used to tune the PID parameters. The method results in a controller which is easy for implementing in practice. The performance of the controller is tested on a sample multi-machine power system model. Simulation results show the effectiveness, robustness and good performance of the proposed controller.     

Reduced order H∞ TCSC controller & PSO optimized fuzzy PSS design in mitigating small signal oscillations in a wide range

This paper proposes hybrid control schemes for compensation of parametric and non-parametric uncertainties arising in modern power systems. The robust loop shaping design procedure considering non-parametric uncertainty term is used to design H_∞ TCSC. To further enhance steady state stability, and consider the effect of parametric uncertainties occurring due to variation in loading conditions, robust TCSC is supplemented with three types of PSS i.e. PSO-PID PSS, PSO Mamdani FPSS and PSO TS FPSS. PSO is used to optimize the parameters of PID based and Fuzzy type PSS. The proposed hybrid control schemes are found to compensate uncertainty well by stabilizing the power system over whole parametric uncertainty range. However, the proposed hybrid controller involving robust TCSC and PSO-Takagi–Sugeno FPSS shows best performance with enhanced steady state stability among all schemes. Also the T–S FPSS performs better as compared to Mamdani FPSS.     

基于DSP的数字励磁调节器

目前广泛使用的同步发电机数字励磁调节器使用简单的单片机控制,采用PID+PSS控制策略,励磁调节器体积大,模块间干扰大,速度低,可靠性差。针对此问题,设计开发了基于DSP(TMS320F2812)的数字励磁调节器,采用PID+PSS+NOEC综合控制策略,实现了大部分调节功能与控制功能的软件化。实验证明,把DSP用于同步发电机数字励磁调节器中,简化了硬件结构,降低了成本,提高了系统可靠性,同时可以实现优良的控制效果。     

Three-dimensional power system stabilizer

Power system stabilizers (PSSs) are used to enhance damping of power system oscillations through excitation control of synchronous generator. The objective of the PSS is to generate a stabilizing signal, which produces a damping torque component on the generator shaft. Conventional PSSs are designed with the phase compensation technique in the frequency domain and include the lead-lag blocks whose parameters are determined according to a linearized power system model. The performance of conventional PSSs (CPSSs) depends upon the generator operating point and the system parameters, but a reasonable level of robustness can be achieved depending on the tuning method. This paper presents a new three-dimensional PSS (3D PSS), which uses rotor speed deviation, rotor acceleration and load angle deviation as input signals. The 3D PSS attempts to return the generator to the state-space origin, based on the generator’s trajectory in state-space and the achievement of torque equilibrium. The 3D PSS is robust to system parameters changes. The proposed algorithm was implemented in a digital control system, tested in a laboratory environment on a synchronous generator connected to the power system, and then compared with CPSS. Experimental results show that the proposed PSS achieves better performance than the CPSS in damping oscillations.     

ASVG的非线性L2增益干扰抑制控制器

将非线性鲁棒控制方法用于先进的静止无功发生器（ASVG）的控制。基于电力系统动态、耗散系统理论框架和非线性L2增益干扰抑制方法,建立了单机无穷大系统中的ASVG鲁棒控制数学模型。模型中考虑了来自发电机转子轴上的机械功率扰动和ASVG输出电压的扰动。并在此基础上,采取递推设计方法构造能量存储函数,以避免求解HamiltonJacobiIssacs不等式,从而得到ASVG的非线性L2增益干扰抑制控制规律。单机无穷大系统的仿真结果证明,与传统PID PSS控制方式相比,在此控制规律下,ASVG能够更有效地阻尼系统振荡,提高系统暂态稳定性能。     

Robust decentralized PID-based power system stabilizer design using an ILMI approach

Thanks to its essential functionality and structure simplicity, proportional-integral-derivative (PID) controllers are commonly used by industrial utilities. A robust PID-based power system stabilizer (PSS) is proposed to properly function over a wide range of operating conditions. Uncertainties in plant parameters, due to variation in generation and load patterns, are expressed in the form of a polytopic model. The PID control problem is firstly reduced to a generalized static output feedback (SOF) synthesis. The derivative action is designed and implemented as a high-pass filter based on a low-pass block to reduce its sensitivity to sensor noise. The proposed design algorithm adopts a quadratic Lyapunov approach to guarantee α-decay rate for the entire polytope. A constrained structure of Lyapunov function and SOF gain matrix is considered to enforce a decentralized scheme. Setting of controller parameters is carried out via an iterative linear matrix inequality (ILMI). Simulation results, based on a benchmark model of a two-area four-machine test system, are presented to compare the proposed design to a well-tuned conventional PSS and to the standard IEEE-PSS4B stabilizer.     

Design of a robust PID-PSS for an uncertain power system with simplified stability conditions

In a deregulated power system uncertainty exists and lack of sufficient damping can lead to Low Frequency Oscillations (LFO). The problem can be addressed using robust Power System Stabilizers (PSS). In this paper, an optimal procedure to design a robust PID-PSS using interval arithmetic for the Single Machine Infinite Bus (SMIB) power system is proposed. The interval modelling captures the wide variations of operating conditions in bounds of system coefficients. In the proposed design procedure, simple and new closed loop stability conditions for an SMIB interval system are developed and are used to design an optimum PID-PSS for improving the performance of an SMIB system. The optimum PID-PSS is attained by tuning the parameters using the FMINCON tool provided in MATLAB. The robustness of the proposed PID-PSS design is validated and compared to other notable methods in the literature when the system is subjected to different uncertainties. The simulation results and performance error values show the effectiveness of the proposed robust PID-PSS controller.     

Performance of a grid-connected wind generation system with a robust susceptance controller

Wind turbine driven induction generators are vulnerable to transient disturbances like wind gusts and low voltages on the system. The fixed capacitor at the generator terminal or the limited support from the grid may not be able to provide the requisite reactive power under these abnormal conditions. This paper presents a susceptance control strategy for a variable speed wound-rotor induction generator which can cater for the reactive power requirement. The susceptance is adjusted through a robust feedback controller included in the terminal voltage driven automatic excitation control circuit. The fixed parameter robust controller design is carried out in frequency domain using multiplicative uncertainty modeling and H_∞ norms. The robustness of the controller has been evaluated through optimally tuned PID controllers. Simulation results show that the robust controller can effectively restore normal operation following emergencies like sudden load changes, wind gusts and low voltage conditions. The proposed robust controller has been shown to have adequate fault ride through capabilities in order to be able to meet connection requirements defined by transmission system operators.     

考虑UPFC实时控制策略的电网功率调节能力研究

提出一种考虑统一潮流控制器(unified power flow controller,UPFC)系统级和换流器级控制策略的线路功率调节能力计算方法,实现了电网正常运行和N-1情况下UPFC对线路潮流有效控制范围的计算。介绍了UPFC工程的控制策略,在考虑并联侧定电压控制和定无功控制特性的基础上实现潮流分析,并以南京西环网UPFC为例,基于江苏电网的实时运行数据对UPFC的实际潮流控制范围进行计算,为电网调度运行提供参考。     

Robust control of doubly fed induction generator for stand-alone applications

The doubly fed induction generator (DFIG) is generally used in the production of the electric energy and more specifically in wind turbines. Currently, a problem of electrical machine control and especially for wind turbines is the change of internal parameters of the machine, which greatly deteriorates the control. In addition, for stand-alone applications, the load and wind speed change frequently. In this paper, a robust control strategy based on the H_∞ control theory is developed for the independent control of the stator voltage amplitude and frequency of a stand-alone DFIG. The DFIG is fed through the rotor windings by a voltage inverter controlled by Space Vector Modulation (SVM). A capacitive and inductive filter is introduced to reduce harmonics on stator voltages and rotor currents. The robust control strategy rejects all the disturbances that may affect the system and that result from the variations of machine parameters, of the rotor speed and of the load. Experimental tests are carried out to verify the effectiveness of the robust control through a comparison with the classical PI regulator in the framework of the Field Oriented Control (FOC) strategy of the DFIG.     

非自衡系统和不稳定系统的预测函数控制

针对非自衡系统和开环不稳定系统，结合预测函数控制、串级调节和PID控制三者的优点，提出了一种PFC-PID控制策略：内回路采用PID控制使对象稳定且快速消除内扰，外回路采用FPC控制，PFC的强鲁棒性保证了在对象特性变化的情况下仍然获得良好的调节品质。仿真结果显示了该控制策略的有效性。     

基于Prony和改进PSO算法的多机PSS参数优化

针对多机电力系统稳定器(PSS)的参数优化问题,提出了采用Prony算法辨识互联电力系统低频振荡的机电模式,利用基于T-S模型模糊自适应的改进微粒群优化(T-SPSO)算法协调PSS参数的控制策略.先采用基于Prony分析的留数法确定PSS的最优安装位置,然后通过对采样数据的Prony分析辨识系统振荡模式的特征值,最后利用所提T-SPSO算法协调优化多机PSS参数.T-SPSO算法根据当前种群最优适应值和惯性权重,自适应更新惯性权重取值,解决了PSO算法的早熟问题.针对IEEE 4机系统的仿真分析表明,基于T-SPSO算法优化后的多机PSS控制器,在2种典型运行方式下都具有更好的控制性能.     

分数阶滑模控制策略提高电力系统暂态稳定性研究

电力系统暂态稳定是电力系统遭受大干扰能够恢复稳定运行的能力,是电力系统安全稳定运行的重要基础。电力系统是一个高度复杂的、强耦合的非线性系统,PSS作为线性控制策略不能够有效抑制大扰动。基于滑模控制,分数阶微积分和有限时间稳定,提出了分数阶滑模控制策略来提高电力系统暂态稳定,使系统能够在有限时间内恢复稳定运行。首先,通过输入输出线性化方法解耦非线性电力系统。然后,提出分数阶滑模控制器并给出其设计和证明过程。同时,给出电力系统在所提出的控制策略性下的收敛时间。最后,在3机9节点电力系统中应用分数阶滑模控制器调节发电机的励磁提高电力系统的暂态稳定,验证了所提出的分数阶滑模控制器的有效性和优越性。     

基于机组实测相频特性的PSS参数整定

提出一种电力系统稳定器(PSS)参数优化整定方法:以机组有补偿相位特性在整个低频段满足要求为目标,确定PSS相位补偿环节时间常数;在临界增益法的基础上,以振荡过程中机组电磁功率振荡最小为目标,整定PSS控制增益;采用最大-最小蚁群算法求解优化模型.采用该方法,基于机组实测无补偿相位特性,对南方电网辖区多台机组PSS参数...     

Pole placement approach for robust optimum design of PSS and TCSC-based stabilizers using reinforcement learning automata

Power system stability enhancement via robust optimum design of power system stabilizers (PSSs) and thyristor controlled series capacitor (TCSC)-based stabilizers is thoroughly investigated in this paper. The design problem of PSS and TCSC-based stabilizers is formulated as an optimization problem where a reinforcement learning automata-based optimization algorithm is applied to search for the optimal setting of the proposed PSS and CSC parameters. A pole placement based objective function is considered to shift the dominant system eigenvalues to the left in the s-plane. For evaluation of the effectiveness and robustness of the proposed stabilizers, their performances have been examined on a weakly connected power system subjected to different disturbances, loading conditions, and system parameter variations. The nonlinear simulation results and eigenvalues analysis demonstrate the high performance of the proposed stabilizers and their ability to provide efficient damping of low frequency oscillations. In addition, it is observed that the proposed CSC has greatly improved the voltage profile of system under severe disturbances.