基于遗传算法的超导磁储能装置H2/H∞鲁棒控制器设计

提出了应用GA(遗传算法)设计H₂/H_∞鲁棒控制器的一般方法。使得在满足闭环系统的H_∞范数小于指定的工程要求的条件下误差信号的H₂范数最小。该问题可归结为一个带约束条件的极小值优化问题，并通过一种改进的遗传算法加以解决。该设计方法能对具有任意控制器结构的控制系统进行参数优化。与传统的鲁棒控制器设计方法相比，所提出的方法不仅可以提高控制器的鲁棒性，还具有易于进行参数优化的优点。将所提出的方法应用于超导磁储能装置（SMES）PI型鲁棒控制器的设计，时域仿真结果表明所设计的控制器具有很好的鲁棒性，在不同的运行工况下均能有效阻尼电力系统的振荡。此外，控制器还具有结构简单、易于工程实现的优点。     

汽轮发电机组的鲁棒H∞扭振滤波器

现代大型汽轮发电机组控制系统的带宽频率与轴系的最低阶扭振模态频率相互趋近,控制系统性能的提高受到扭振稳定性要求的制约。文中将未建模扭振模态考虑为刚体转子的模型摄动,扭振转速分量是这一模型摄动的结果,利用广义观测器估计刚体转速,构造出一种新型的扭振滤波器,以消除汽轮发电机组控制系统与轴系扭振的相互作用。与常规的扭振滤波器不同,所提扭振滤波器能够衰减扭振分量而在通频带无任何附加相位滞后,并且提供有可用于鲁棒设计的附加自由度。针对实际工程背景对扭振滤波器提出鲁棒性要求,并表示为H_∞性能指标的形式,利用混合灵敏度方法设计出一种鲁棒H_∞扭振滤波器。仿真结果验证了鲁棒H_∞扭振滤波器在高频段衰减能力强、在通频带无附加相位滞后、鲁棒性好的优点,利用它能够有效防止扭振失稳,促进快速响应的高性能控制系统的应用。     

汽轮机调速系统的自适应L2增益干扰抑制控制

提出一种预置反馈的方法,推导出汽轮机调速控制系统的端口受控哈密顿系统（PCH system）模型,进而根据PCH系统的自适应L₂增益干扰抑制方法,设计汽轮机调速系统的控制规律。仿真结果表明,这种控制方法能有效抑制干扰,可以在大干扰条件下提高系统暂态稳定性。     

基于哈密顿理论的发电机汽门鲁棒非线性控制器设计

提出了利用Hamiltonian能量函数理论设计非线性鲁棒控制器的方法,设计了发电机汽门的非线性鲁棒控制器,并且给出了估计干扰抑制增益的一个充分条件,所得控制器结构简单,易于工程实现。由于在控制器设计中未用到任何线性化方法,因而所得控制器充分利用了系统的非线性特性。仿真结果证实了理论分析的正确性与控制规律的有效性。     

考虑非线性负荷的静止无功补偿器控制研究

针对电力系统具有非线性负荷的情况下，在经典的非线性系统几何结构理论的发展基础上，结合非线性系统微分几何理论，提出了关于微分代数系统的M导数、M括号等一些新的概念和定义，并详细推导了微分代数系统的完全精确线性化设计。然后将其应用于具有非线性负荷的电力系统静止无功补偿器的控制，得到了非线性控制规律。仿真结果表明，所设计的静止无功补偿器非线性控制器与常规PID控制相比，具有较好的阻尼特性和电压维持能力，同时，由于该设计计及了负荷的变化，从而更接近于实际情况。     

基于超导储能的暂态稳定控制器设计

设计了用于提高电力系统的暂态稳定超导储能(SMES)装置的非线性鲁棒控制器,并从数字仿真和动模实验两方面进行了验证。为了简化动态性能分析和控制器设计,在实验样机的基础上,提出了新的基于电流型变流器的SMES的动态模型,并将其转化为标幺制模型。通过外部干扰的引入,得到了装设SMES的单机无穷大系统的动态模型,并采用精确线性化方法和线性H∞控制理论设计了SMES的非线性鲁棒控制器。为了验证该控制器的效果,对装设SMES单机无穷大系统进行了数字仿真和动模实验,并将其与常规PI控制器进行了比较。仿真和实验结果都证明了非线性鲁棒控制器具有良好性能。     

多机系统TCSC多目标H∞控制器设计

在电力系统中装设可控串联补偿（TCSC）可以改善系统的暂态稳定性、动态性能,以及提高远距离联络线的传输能力。为了更好地利用该装置,文中应用直接反馈线性化和H_∞控制理论,设计了一种多机系统TCSC多目标H_∞控制器,该控制器中的变量均为局部可测量,从而具有工程实用性。两机系统的仿真结果表明,采用该控制器可以满足系统功角稳定性、频率稳定性、控制系统消耗能量最小等多项目标。同时,该控制器可以抑制干扰,很好地适应系统运行方式的变化。     

自适应振荡过程的Ucosφ精确算法

提出了自适应跟踪振荡过程的精确计算方法，这种算法将差分全波傅里叶算法作为数字滤波器对输入信号进行滤波，然后用短数据窗（3点）先算出信号的频率，进而精确计算出信号的幅值和相位。用此算法求出的I>Ucosφ数值精度高，收敛性好，更真实地反映了电力系统振荡过程中发生三相短路时保护安装处电压和电流的变化；因此可以大大缩短I>Ucosφ作为电力系统振荡过程发生三相短路判别元件的动作时间，提高整套保护的性能。数字仿真结果验证了该算法的正确性。     

EXCITATION CONTROL FOR POWER SYSTEMS WITH NO NLINEAR LOADS

The paper describes 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.     

用傅里叶变换测量介质损耗因数tan δ的软件同步算法

计算分析了当电网频率漂移时,通过传统的离散采样用快速傅里叶变换（FFT）计算电力设备的介质损耗因数tan δ时,由于硬件设计的采样周期不能随电网频率漂移而相应地改变,从而给tan δ测量结果带来严重的计算误差。提出了一种利用采样序列数据修正方法,这种方法通过检测信号的周期确定周期修正量,根据大于或小于0决定是增加或者减少采样周期来解决传统傅里叶计算方法的计算误差问题,文中阐述了算法的实现过程,并介绍了一种适用于实验室和现场的通过阻容变化改变相位角的简单而准确的模拟电路。计算机模拟和实测结果表明,文中提出的算法可很好地解决传统傅里叶方法测量tan δ的精度与稳定性不高的问题,在12位A/D精度、电网频率波动±0.2 Hz条件下,数据经过修正计算后tan δ测量误差小于5×10^-4,对提高tan δ测量精确度及稳定性有重要作用,可在目前广泛使用的微控制单元（MCU）中很好地实现。     

分散励磁与超导储能装置的干扰抑制控制

提出了一种新的设计多机电力系统中励磁和超导储能装置的分散L₂增益干扰抑制控制器的方法。文中首先建立了含超导储能装置的多机电力系统的动态模型，继而利用递推方法设计励磁和超导储能装置的增益干扰抑制控制器，所得控制器可以利用本地测量量实现。计算机仿真结果说明了所设计的控制器可以提高系统的暂态稳定性，显著改善系统的动态性能。     

Augmentation of transient stability using a superconducting coiland adaptive nonlinear control

The very nonlinear nature of the generator and system behaviour following a severe disturbance precludes the use of classical linear control techniques. In this paper, a nonlinear adaptive excitation and a thyristor-controlled superconducting magnetic energy storage (SMES) unit is proposed to enhance the transient stability of a power system with unknown or varying parameters like equivalent reactances of the transmission lines. The SMES unit is located near the generator bus terminal in a power system. A nonlinear feedback control law is found which linearizes and decouples the power system. An adaptive control law is used to design the controller for the generator excitation and SMES system. Simulation results demonstrate that the proposed controller can ensure transient stability of a single-machine-infinite-bus system under a large sudden fault which may occur near the generator bus terminal     

超导磁储能系统抑制风力发电功率波动的研究

建立含超导磁储能装置(SMES)的单机无穷大系统的Phillips-Heffron模型,导出含SMES电力系统总的电磁转矩表达式,从理论上分析SMES对增强系统阻尼的作用.并设计了SMES非线性比例积分微分控制器,数字仿真结果验证了SMES阻尼系统功率振荡的特性,同时表明该控制器具有较好的鲁棒性.     

A heuristic‐based design of robust SMES controller taking system uncertainties into consideration

In this paper, a heuristic‐based design of robust superconducting magnetic energy storage (SMES) controller is proposed taking system uncertainties into consideration. The SMES model with active and reactive power controllers is used. In addition, the effect of SMES coil current is also included in the model. The power system and the SMES unit with the designed controller are formulated as an optimization problem. The proposed objective function considers both the damping performance index and the robust stability index. In particular, the robust SMES controller is designed to enhance the system damping performance and robustness against system uncertainties such as various load and system parameter changes. The robust stability margin is guaranteed in terms of the multiplicative stability margin (MSM). In the proposed method, the robust SMES active and reactive power controllers are designed systematically by using hybrid tabu search and evolutionary programming, so that the desired damping performance and the best obtainable MSM are acquired. Finally, the designed SMES controller is examined under different situations to evaluate and confirm the effectiveness and robustness via eigenvalue analysis and nonlinear simulations. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

超导储能和超导限流器在电力系统应用中的比较

介绍了超导储能和超导限流器的发展现状和研究进程。针对它们在电力系统的应用情况,从稳定效果和控制方法方面比较了两者的优劣。超导储能和超导限流器都能有效地抑制电力系统功率振荡,其中,超导储能系统的控制复杂程度要高于超导限流器,但超导储能系统对电力系统的稳定效果要优于故障限流器。     

Enhancement of transient stability by fuzzy logic-controlled SMES considering communication delay

This paper presents a fuzzy logic-controlled superconducting magnetic energy storage (SMES) for the enhancement of transient stability in a multi-machine power system. The control scheme of SMES is based on a pulse width modulation (PWM) voltage source converter (VSC) and a two-quadrant DC–DC chopper using gate-turn-off (GTO) thyristor. Total kinetic energy deviation (TKED) of the synchronous generators is used as the fuzzy input for SMES control. Communication delays introduced in online calculation of the TKED are considered for the actual analysis of transient stability. Global positioning system (GPS) is proposed for the practical implementation of the calculation of the TKED. Simulation results of balanced fault at different points in a multi-machine power system show that the proposed fuzzy logic-controlled SMES is an effective device for transient stability enhancement of multi-machine power system. Moreover, the transient stability performance is effected by the communication delay.     

基于超导储能装置的联络线功率控制

改变了以往将超导储能装置安装在发电机出口处的策略,利用该装置与系统间有功和无功功率交换的灵活性,进行互联系统联络线的功率控制.控制目标由传统的驱使系统恢复到故障前的稳定运行点,转为跟踪系统惯量中心,以较小的控制代价尽快将系统拉回同步,并迅速平息故障后的区域间功率振荡.利用反步法为超导储能装置的有功环节设计了鲁棒控制器,使闭环系统对建模误差及有界的外部扰动具有鲁棒性.最后利用PSS/E对所提出的控制方案在4机2区系统上进行了数字仿真,证明了该方案的有效性.     

A robust SMES controller design for stabilization of inter-area oscillations based on wide area synchronized phasor measurements

This paper proposes a robust power controller design of superconducting magnetic energy storage (SMES) based on wide area synchronized phasor measurement units (PMUs) for stabilization of inter-area oscillation. The structure of active and reactive power controllers of SMES is the first-order lead/lag compensator. Assuming multiple PMUs are located in an interconnected power system, the steady state phasor data are obtained by applying the small load perturbation. Using the phasor data, the simplified oscillation model (SOM) included with SMES power controllers can be identified and applied to estimate the dominant inter-area oscillation modes. In the robust control design, unstructured system uncertainties such as various operating conditions, system parameters variation, etc., are represented by the inverse additive perturbation and included in the SOM. To enhance the system robust stability margin, the optimization of SMES control parameters is solved by genetic algorithm in the SOM. Simulation studies in the West Japan 6-machine power system confirm that the robustness of the proposed SMES is much superior to the conventional SMES against various operating conditions and fault locations.     

超导储能系统提高风电场暂态稳定性研究

应用超导储能系统(SMES) 对提高风电场的暂态稳定性进行了研究。在深入研究超导储能系统运行原理的基础上,建立了基于电压型换流器(VSC)的超导储能系统模型,实现了有功功率和无功功率的解耦控制,并提出了有功、无功功率综合控制策略。利用PSCAD/EMTDC软件进行了仿真计算,结果说明超导储能系统不但能够在风速波动时平滑风电场的功率输出,而且能够提高风电系统的暂态稳定性。