Optimizing nonutility generating facility reactive power capability

This article addresses a case study of nonutility generation station designed with two gas turbine generators and one steam turbine generator operating in a combined cycle mode and connected to an existing grid system. This article is based on generator step-up (GSU) transformers with fixed taps that can only be adjusted when the transformer is de-energized (no load). The effects of equipment selection and plant operation settings are examined for optimizing the reactive power capability of the station based on projected operating conditions     

Transient Response of an Incinerator Plant by Considering Boiler Model With Dynamic Steam Variation

This paper investigates the effect of boiler steam system on transient response of turbine generators for an incinerator plant. By performing the test of cogeneration units, the mathematical models of turbine generator, governor, and boiler have been identified, which are used in the computer simulation to solve the steam pressure and system frequency of the cogeneration system for islanding operation after tie line tripping. Due to the variation of trash heat value, the power output of the cogeneration unit is stochastically varied with the steam generation for normal operation, which will cause the dynamic change of tie line power flows. For the severe fault contingency of external power systems, the cogeneration system will be isolated by tie line tripping, and the system frequency response is then determined by including the boiler effect to represent the dynamic steam generation. Because of more sluggish response of the boiler system caused by unstable trash heat value, the transient response of the incinerator governor system is inferior to that of conventional industrial cogeneration systems. To maintain the system stability for successful islanding operation of the incinerator plant, the amount of load shedding after tie line tripping has to be properly determined based on the transient stability analysis by considering the response of boiler system.     

大型“二拖一”燃气-蒸汽联合循环机组仿真机的研制与开发

系统介绍了M701F型“二拖一”燃气-蒸汽联合循环机组仿真机的研发背景、硬件配置;阐述了以CyberSim图模库一体化通用仿真支撑平台为核心的仿真支撑系统的技术特点、软件构成以及燃气轮机数学模型。利用该仿真系统实现了“二拖一”燃气-蒸汽联合循环机组全工况实时仿真。测试结果表明,燃气轮机、余热锅炉、蒸汽轮机及发电机等模型精度均达到了仿真机设计要求,且具有良好的静态精度和正确的动态响应特性。该仿真机除了可对运行人员进行培训外,还可用于电厂控制策略优化及运行方式分析与研究。     

Performance of gas turbine-based plants during frequency drops

A combined cycle power plant, which combines a gas turbine and a steam turbine, can achieve high energy efficiency. Many combined cycle plants have been installed in the world. However, a large-scale blackout occurred in Malaysia in 1996. Combined cycle and gas turbine plants sequentially tripped out. The cause of this chain trip was thought to be a system frequency drop. Considering these backgrounds, it is important to study dynamic behavior of combined cycle plants. Several dynamic models of the combined cycle plant have been proposed. In our analysis, we use some of them and build a model for a single-shaft combined cycle plant. We execute numerical simulations to see how the combined cycle behaves when the system frequency drops.     

联网燃气轮机的动态特性分析

介绍了燃气轮机发电机组及其励磁系统和调速系统的数学模型,并在MATLAB中建立了燃气轮机励磁系统的仿真模型,对其动态特性进行了仿真计算.利用电力系统分析综合程序(PSASP 6.1版)建立了燃气轮机励磁系统及调速系统的用户自定义模型,并结合典型配电网,对并网后的燃气轮机进行了暂态分析和小干扰稳定分析计算,分析了励磁系统及调速系统的有关参数对燃气轮机动态特性的影响,为研究分布式电源对电力系统暂态特性的影响奠定了基础.     

高频事故下潮流转移性质和调速器状态转移控制

为了缓解500kV电网短路电流增长趋势,建设具有抗灾能力的智能电网,需要采取电源—电网—负荷融合的电网规划设计理念,将大容量机组接入220kV地区电网。为了解决由此而产生的"大机小网"高频稳定问题,文中提出了一种高频稳定控制方法。该方法根据高频事故时孤网潮流转移功率信号对调速器实施状态转移控制,能够使机组调速系统快速和准确地跟随孤网突变,将汽轮机组调速系统高频稳定裕度从当前的9%提高到50%以上,水电机组调速系统的性能也得到大幅提高,控制系统具有分散协调性、坚固性和兼容性,能够使灾害破坏下残余的送端电网具备生命自持的能力。最后,对机组潮流转移功率的性质进行了推导和仿真,并论述了调速器状态转移控制的方法、模型和仿真效果。     

燃气-蒸汽联合循环进气冷却系统对机组性能影响研究

以PG9171E型燃气-蒸汽联合循环电厂为研究对象,对联合循环及进气冷却系统进行建模。分析了该机组加装进气冷却系统后燃机侧、余热锅炉侧和蒸汽轮机侧系统性能的变化情况。结果表明该E型联合循环机组加装进气冷却系统后,进气温度每降低10 ℃,燃机侧出力上升约9%,余热锅炉效率下降约3%。通过蒸汽参数的调整充分利用余热资源能使汽轮机多出力2.1 MW,联合循环效率上升约0.3%。     

增强型调速器对中国云南电网超低频振荡影响分析

云南电网在部分水电机组中采用增强型调速器,会引发超低频振荡,并严重威胁异步电网频率安全。为揭示水电机组增强型调速器影响云南电网频率的原因,通过对系统频率偏差从不同方向穿越一次调频死区时的动力学行为进行理论计算和时域仿真,论证了增强型调速器在水电机组一次调频死区附近没有稳定平衡点,且当系统频率偏差缓慢穿回一次调频死区时,在超低频段引入约90°的相位滞后,进而降低系统频率安全稳定裕度。最后借助小扰动分析工具计算了包含水轮机、调速器、发电机模型的单机系统特征根,通过对比仿真,说明增强型调速器不仅与水锤效应在超低频段有相似的负阻尼效应,还是引发超低频振荡的扰动源头之一,使超低频振荡持续且无法衰减。     

水轮发电机组低频振荡机理与稳定特性

为深入探究水轮发电机组低频振荡机理,揭示系统稳定性规律,本文利用压力引水管道弹性模型、调速器模型和三阶发电机模型,建立水轮发电机组非线性数学模型。通过数值模拟来验证所建水轮发电机组模型与实际系统的一致性和正确性。进一步地,根据水轮发电机组阻尼特性,优化PID参数,系统分析了随调速器参数变化水轮发电机组的低频振荡机理及稳定特性。此外,为了定量探究关键参数对系统稳定性的影响规律,对处于稳定振荡模式下的系统进行阻尼灵敏度分析,得到了对系统稳定性影响较为显著的关键参数。研究成果为机组稳定运行提供理论依据和技术支撑。     

利用不补燃型燃气-蒸汽联合循环改造燃煤电厂方案的研究

介绍了燃气轮机及其联合循环发电技术(GTCC)的优点.着重分析了应用不补燃余热锅炉型燃气-蒸汽联合循环对现有燃煤电厂进行改造的基本热力学原理,并针对某燃煤电站改造成常规不补燃余热锅炉型燃气-蒸汽联合循环的发电效率和经济性进行理论分析和计算,论证其在技术上和经济上的可行性.     

联合循环电厂建模综述

由燃气轮机、余热锅炉和蒸汽轮机组成的联合循环电厂由于其高效率、低排放等优良性能,在发电领域中起到了日益重要的作用。本文回顾了联合循环电厂在国内外的发展及应用状况,介绍了其基本工作流程,总结了近年来对其建模的各种方法,着重讨论了基于机理建模和基于系统辨识建模两种方法,并对各种方法进行了分析比较,最后对我国联合循环电厂的发展进行了展望。     

Emergency generator startup study of a hydro turbine unit for a nuclear generation facility

This paper reports the implementation of synchronous generator, induction machine, hydro turbine, and governor system, and excitation and automatic voltage regulator system models for transient stability study. These models are frequency dependent and are suitable for system transient studies involving drastic frequency changes, including generator startup and emergency load startup. A computer simulation program has been developed using these models for a transient stability study. The developed program is further validated and verified using real system testing data that includes the cases of generator startup and full-load shed in a nuclear power generation plant. Validation results show overall an excellent correlation between the computer simulation and the field-testing data. As a result, the program has been accepted by the plant for system modeling and emergency generator startup simulation studies.     

Dynamic behavior of a combined cycle power plant in the presence of a frequency drop

A combined cycle power plant which combines a gas turbine and a steam turbine can achieve high energy efficiency. Many combined cycle plants have been installed worldwide. However, a large‐scale blackout due to combined cycle chain trip‐out occurred in Malaysia in 1996. The cause of this chain trip was considered to be a large drop of system frequency. Thus, there is a need to investigate the stability of the combined cycle power plant for the frequency drop. Several dynamic models of a combined cycle plant have been proposed. In our analysis, we use some of them and build a model for a single‐shaft combined cycle plant. We execute numerical simulations to see how the combined cycle plant behaves when the system frequency drops. The cause and the countermeasure of the combined cycle plant trip‐out are explained. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(3): 9–19, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10117     

适应整体煤气化联合循环燃气轮机改型方法分析

整体煤气化联合循环(IGCC)是多种设备、多种技术集成的一个复杂系统,整合了化工、发电等各方面技术为一体,包括了气化炉、空分系统、燃气轮机、余热锅炉、蒸汽轮机等设备。通过分析煤气化合成气与天然气的差异以及煤气化合成气对燃气轮机的影响,展开燃用天然气燃气轮机改型设计为燃用合成气的方法探索,总结改型设计经验,为整体煤气化联合循环燃气轮机设计奠定基础。     

特高压受端电网燃气轮机发电机组的深度调峰研究

随着越来越多的特高压线路接入电网,如何利用发电机组的调频和调峰特性来确保电网安全显得尤其重要。根据燃气轮机发电机组的调峰特性,分别对燃气轮机发电机组快速启动和低负荷运行深度调峰进行了影响因素分析和试验研究,获得了相关的运行数据和经验,为特高压线路接入电网时利用燃气轮机发电机组调峰来确保电网安全提供了参考和思路。     

Phase compensated gas turbine governor for damping oscillatory modes

With market deregulation, there is constant pressure to utilise existing assets in more effective ways in order to achieve high levels of performance and as governor technologies mature the ability of governors to achieve much more than the standard power–frequency regulation function increases. Thus, this paper has focused on a more active use of governor control for a gas turbine to provide improved system stabilisation and performance via the inclusion of phase compensation in the governor control loop. Due to the decoupled nature of the mechanical power and excitation control loops, performance improvement via governor control does not interfere with generator voltage regulation, which is a drawback of conventional generator damping provision via a power system stabiliser (PSS). In addition, the mechanical power control loop is also less affected by the operating condition of the power system and is hence more robust. It is shown that inclusion of appropriate phase compensation in the governor control loop can improve dynamic and transient stability, either alone or in conjunction with a PSS in the exciter control loop, without adversely interfering with voltage control or changing steady state power–frequency regulation.     

西门子V94．3A燃气轮机配套余热锅炉设计

华能上海石洞口燃机电厂燃气—蒸汽联合循环工程选用西门子V94.3A型燃气轮机,余热锅炉是国内设计生产的第一台配该型号燃机的余热锅炉。由于机组整体性能由西门子保证,故余热锅炉的系统设计必须考虑满足西门子提出的相关要求。介绍了余热锅炉主要设备的结构特点,详细介绍了配V94.3A型燃机的余热锅炉设计技术数据,可为国内大型联合循环机组余热锅炉的设计提供参考。     

水轮发电机失磁的动态过程分析

为了分析大型水轮发电机失磁过程和验证失磁保护方案，建立了包括水轮机、发电机、调整器和励磁调节装置在内的全系统数学模型，并编制了仿真软件。发电机失磁后的动态过程是比较复杂的机电过程，发电机组各个环节的结构和参数都将影响它的动态过程。在模拟发电机组上进行了失磁实验和仿真分析，实验结果验证了仿真结果的正确性。对某水电站250MW的水轮发电机进行了失磁过程的仿真研究，仿真结果对工业实际有重要参考价值。     

风电机组对电力系统暂态稳定性影响分析

风电机组作为环境友好型发电的最大来源在电网中的规模日益扩大,必将影响电力系统的稳定性。文章首先对比了恒速异步(CSWT),双馈变速(DFIG)及直驱同步(DDSG)等市场上广为应用的三种风电机组的结构,分析了各个机组的降阶数学模型;通过一款基于Matlab的电力系统分析工具箱PSAT研究了不同故障持续时间下的风电机组暂态稳定性和系统暂态稳定性,对三种机组及其系统的暂态稳定性进行了分析对比;最后讨论了风力发电机组参数对机组暂态稳定性的影响,得知,发电机参数Rr的增加和Xr、Xs的减小有利于恒速风电机组暂态稳定性的提高,Xm、Rs对机组暂态稳定性影响不明显。     

Performance and efficiency control enhancement of wind power generation system based on DFIG using three-level sparse matrix converter

Nowadays, the power generation systems based on wind turbines is increasing continuously in the world. Hence, there are intense efforts provided by researchers for the development of this area. In high power system applications, multilevel converters are a competitive alternative to the two-level inverters. In this paper, a three-level sparse matrix converter (SMC3l) associated to a grid connected variable speed wind generation (VSWG) scheme using a doubly fed induction generators (DFIGs) is investigated. Therefore, the dynamic behavior of a wind generator, including models of the wind turbine, DFIG, SMC3l control algorithm and power control is studied. Simulation results of the dynamic models of the wind generator are presented, for different operating modes sub-synchronous, synchronous and hyper-synchronous, to show the good performance and the efficiency control enhancement of the VSWG system using the proposed SMC3l.