Automatic Generation Control in an Interconnected Power System Incorporating Diverse Source Power Plants Using Bacteria Foraging Optimization Technique

This article presents automatic generation control (AGC) of a two-area interconnected power system with diverse energy sources using the bacteria foraging optimization technique. The control areas of interconnected power systems consist of hydro, thermal, and gas power plants. In this study, the proportional-integral-derivative (PID) structures of AGC regulators are designed for various case studies identified herein. An artificial intelligent optimization algorithm using the modeling behavior of E. Coli bacteria present in human intestines, is applied to tune the gains of PID structured AGC regulators. The closed-loop system dynamic response plots are obtained with designed AGC regulators for various power system models. The effectiveness of the proposed AGC regulators is demonstrated in the wake of a 1% step load disturbance in one of the control areas. It has been shown that the system dynamic responses subject to a step load disturbance are superior over other power plant combinations in a control area with only thermal and gas power plants participating in the AGC schemes, and it is sluggish/poor when only hydro power plants participated in the AGC scheme as one of the diverse sources in the power system.     

交流电机离散时间电流调节器的设计

分析了运行在较高基频与采样频率的比值下异步电机的离散时间电流调节器的特点,该情况普遍应用在高速列车驱动和大型牵引驱动上.若电流调节器的设计不能很好地满足控制系统离散特性,在较高的基频与采样频率比值下,系统会发生严重的振荡或者不稳定响应.通过一个含SVPWM延迟的离散时域交流电机模型,设计离散时域复矢量电流调节器.仿真和...     

励磁控制引起的双馈风电机组轴系扭振机理

从电磁转矩观点出发,证明了双闭环比例积分(PI)调节参数和前馈补偿参数是影响电磁转矩性质的2个关键因素.由于PI调节器积分常数取值的不同,在励磁调节器框图上从q轴励磁电压参考点到有功功率点之间的相位差可能在大范围内变化,这是影响阻尼转矩的因素之一.另一个影响因素是前馈补偿项参数——定、转子绕组间互感系数,由于设计控制器时所使用的该互感系数很难保证就是电机的实际参数,故存在误差,误差的正负性和大小对阻尼转矩的方向和大小有直接影响.上述2个独立因素可组合为4种情形,文中研究了各种情形下电磁转矩的阻尼性质,其中有2种情形将产生电气负阻尼,会导致轴系扭振.最后,通过时域和频域相互校验的仿真手段验证了机理分析的正确性.     

Synthesis of electric drive systems invariant to parametric and external disturbances by the method of polynomial equations

The possibilities of finding a general solution to a polynomial equation for the synthesis of electric drive systems are considered. It has been shown that regulators with adaptive properties can be designed on their basis, ensuring low system sensitivity to parametric and external disturbances. Examples of the use of such regulators in DC and AC electric drives are presented.     

参数自适应Fuzzy调节器在变频调速中的应用

本文旨在研究 Fuzzy 调节器在微机控制变频调速系统中应用的问题。常规 Fuzzy 调节器参数在控制过中是不变的,满足不了变频调速系统响应速度快且稳态精度高的要求。文中讨论的参数目适应 Fuzzy 调节器在一定程度上解决了此问题,仿真结果表明了此调节器的优良性能。     

LDO与VLDO的设计原理及性能测试

首先分析了低压差稳压器(LDO)、准低压差稳压器(QLDO)和超低压差稳压器(VLDO)的设计原理,然后对几种线性稳压器的性能作了比较,最后通过低压差稳压器的测试数据来证明其优良特性。     

采用双直流电流滞环调节器的矢量控制PWM变频调速系统

矢量控制变频调速系统因基诸多的优良特性,具有广阔的发展和应用前景,本文提出了一种性能良好的交流电机矢量控制ＰＷＭ调速方案,采用两个电流滞环调节器,滞环调节器的输出通过ＥＰＲＯＭ电压矢量开关表选择合适的电压矢量输出,控制逆变器,运行结果表明,该系统具有良好的稳态和动态性能。     

OPTIMAL REGULATORS FOR SOLID ROTOR D. W. R. SYNCHRONOUS GENERATOR BY OUTPUT FEEDBACK

ABSTRACT

The paper deals with the design of optimal regulators (continuous and discrete) for divided winding rotor (d. w. r.) synchronous generator by output feedback using pole placement technique where the machine model includes in detail the solid-iron effect of the rotor body. The effect of solid rotor on the design of regulators' gains has been estimated. The effect of saturation of the rotor body on the design of continuous regulators and the effect of sampling period on the design of discrete regulators have also been studied. Finally, a comparison is made between the feedback gain values obtained from continuous and discrete models.     

交流调节器在军用DC/AC逆变器中的应用研究

针对传统PI调节器对交流输入信号会产生静态误差的缺点,运用伺服控制系统中的直流调节器转交流调节器的理论,提出了具有良好交流跟踪和调控特性的交流调节器,并将其引入军用DC/AC逆变器控制系统的控制调节器环节。理论分析和仿真实验表明,该方法可以消除静态误差,使稳态误差为零。该新型调节器可用于单相或三相逆变器,使之获得良好的输出,能够满足武器装备对军用DC/AC逆变器高质量输出的需求。     

A Phantom in Our Midst: Are PUCs Playing Fair with ADITs?

By requiring restructuring utilities to credit the amount of accumulated deferred income taxes on their books against stranded investment charges, the Connecticut Department of Public Utility Control might have discovered a way for state regulators to take back with one hand what they have been legislatively mandated to grant with the other.     

一种新型交流PI调节器及其在逆变电源中的应用

针对传统的PI调节器会对交流输入信号产生静态误差,引用伺服控制系统中的直流调节器转换为交流调节器的理论,推导出一种新型的交流PI调节器,也即谐振控制器。理论分析和仿真结果表明:该调节器能对交流输入信号达到无静差跟踪并能获得良好的动态性能。同时,该调节器可适用于三相CVCF逆变电源和单相CVCF逆变电源。     

Increasing the efficiency of joint operation of a solar-power plant with an industrial alternating-current network

The use of photoelectric-converter modules (PCM) with integrated direct-current regulators in low- and medium-power-supply systems working jointly with an industrial network permits production to be increased of the power generated by photoelectric-converter modules due to operation of all modules in the maximum power-generation mode. With the decrease in the intensity of solar radiation of some of the chain of the series-connected photoelectric-converter modules, the simultaneous work of all modules of the chain in the maximum power selection mode can lead to the appearance of overvoltages on elements of direct-current regulators integrated into the modules. A means is proposed in this article to control the chain of seriesconnected photoelectric-converter modules with integrated direct-current regulators. The control algorithm of the direct-current regulators permitting one to equalize the voltage at the output of the series-connected regulators under very nonuniform illumination of the photoelectric-converter modules. Computer models are studied, and results of simulation in Matlab/Simulink software system are presented.     

消除直流系统异常对励磁调节器的影响

由于1台机组单元控制直流电源消失,使相应机组调节器逆变灭磁,分析了该公司机组相关直流控制回路接线及调节器试验结果,给出了消除直流控制电源对调节器影响的方法,提高了调节器的稳定性,保证了机组及电网的安全。     

基于遗传算法的PWM斩波变换器优化设计

基于遗传算法对斩波变换器的数学模型中的优化目标及约束因子进行分析,将每半个工频周期开关k次的斩波变换器的输出电压表示为傅里叶级数的形式,以最优开关角度为控制量,输出电压和谐波含量最小为目标,构成多目标优化问题。利用遗传算法求解非线性规划问题的优势,将遗传算法用于斩波变换器控制参数(开关角)的优化设计。优化结果表明,采用改进的遗传算法用于斩波变换器控制参数(开关角)的优化设计,能取得令人满意的结果。     

一种调压开关触头装置的优化设计

为解决农村等偏远地区电压偏低问题,配合国家农村电网改造工程,先后开发了多种电力智能调压器.开发过程中遇到某型号调压开关使用的传统触头部件存在接触不良、拉弧等问题,严重影响了调压器的使用性能.在对产品优化分析的基础上,设计了一种闭合自紧式触头装置,通过动触头和静触头充分可靠的接触,保证了调压开关运行的稳定性,增加了通流能...     

双输入直流变换器的建模与闭环系统设计

在采用两个甚至多个输入源的新能源联合供电系统中,用单个多输入直流变换器(Multiple-Input Converter, MIC)代替原有的多个单输入直流变换器,可以简化电路结构,降低系统成本。采用MIC构成的新能源联合供电系统是一个典型的多输入-多输出耦合系统,因此,闭环系统的设计非常复杂,本文将以双输入Buck变换器为例,进行系统建模以及闭环调节器的设计,使得该系统稳态和动态性能达到要求。最后通过一个400W的实验样机验证该设计方法的有效性。此设计方法也可以应用于其它的双输入直流变换器构成的新能源联合供电系统中     

基于调度运行管理系统的配电网故障研判方案

对于在电力调度控制中心内进行配电网故障研判系统建设的问题,讨论了多种方案,分析了各自的优缺点,提出了基于调度运行管理系统(OMS)建设配电网故障研判系统的方案。该方案在与其他系统共享数据的基础上,根据配电网实时状态,采用归集方法,实现了故障诊断及定位。为实现此方案,研究了图模图数一体化、配电网故障辅助研判等关键技术,并进行了总体设计。实践证明,该方案不仅能有效支撑配电网故障诊断,还可实现配电网调度与抢修指挥业务的良好融合。     

Next-generation PBR

The transformation of the electric utility industry has resulted in a shift in emphasis on consumers, regulators and utilities from the traditional input-focused regulation to an output-focused regulatory framework. This article examines the implications of these transformations for the design of a new performance-based regulatory mechanism.     

It’s high time to transition away from volumetric distribution rates: Why not a 3-part tariff?

This essay attempts to contribute to the ongoing debate about the design of electricity rates for residential customers. The debate has centered on fixed versus volumetric charges, and then later about introducing demand charges. The interest in demand charges has sprung largely from fundamental flaws in the prevailing rate design for residential electric service, especially as those flaws have magnified under a continuously evolved market and public-policy environment. This essay argues that demand charges are worthy of study by regulators because of their superior features compared with prominent alternatives, namely, volumetric and straight-fixed variable rates. But it can be a long road before they become commonly accepted. This will only happen when the political cost of the prevailing rate structure becomes prohibitively high. In the meantime, regulators should begin the process of moving away from volumetric rates, for the sake of both efficiency and equity.     

AGC of a multi-area multi-source hydrothermal power system interconnected via AC/DC parallel links under deregulated environment

This paper proposes the automatic generation control (AGC) of an interconnected multi-area multi-source hydrothermal power system under deregulated environment. The two equal control areas with hydro and thermal generating power sources are interconnected via AC/DC parallel links. The optimal proportional integral (PI) regulators are designed for the proposed power system to simulate all power market transactions which are possible in a restructured power system. The concept of DISCO participation matrix (DPM) is harnessed to simulate the transactions. Eigenvalue study is conducted to assess the effect of AC/DC parallel links on system performance. The study is also conducted, considering appropriate generation rate constraints (GRCs) for thermal and hydro generating sources. Further, the dynamic responses of the proposed multi-source hydrothermal power system are compared with single-source thermal–thermal power system and it has been ascertained that the responses of proposed power system are sluggish with large overshoots and settling times. Finally, the study is extended to frame and implement optimal PI regulators for the first time for the AGC of a conventional two-area non-reheat thermal power system with governor dead-band nonlinearity. The superiority of the optimal PI regulators has been established by comparing the results with recently published best claimed craziness based particle swarm optimization (CRAZYPSO) and hybrid bacterial foraging optimization algorithm-particle swarm optimization (hBFOA-PSO) algorithms based PI controller tuned for the same interconnected power system.