稳定计算用发电机励磁系统模型参数测试及校核分析

针对稳定计算用发电机励磁系统参数测试建模,在分析励磁控制系统各部件模型参数的基础上,提出了适合于工程实际应用的测试建模及校核分析方法,并结合具体的现场试验,给出了试验结果分析及仿真计算校核示例,得到了符合稳定计算要求的发电机励磁系统模型参数。     

同步发电机励磁系统模型及参数自动校核

基于华中电网直调机组励磁系统参数测试报告及现场实测建模的校核判据,研究出同步发电机励磁系统模型及参数自动校核方法,编写了自动校核软件,并通过现场实测与仿真计算对比的方法验证励磁系统实测建模的正确性.该方法解决了人工建模工作量大、耗时长等问题,为生产运行和规划建设提供了更具参考意义的励磁系统模型和参数.     

直流励磁发电机组励磁系统参数测试建模及仿真校核

通过励磁系统的现场试验,采用电力系统分析综合程序PSASP中的励磁系统模型,得出可用于电网稳定计算的柘溪水电厂6号发电机组励磁系统的实测模型和参数。文章总结了使用PSASP进行励磁系统参数仿真的步骤,并给出试验数据与仿真数据的对比结果,结果验证了上述方法的正确性和实用性。     

华中-川渝联网稳定计算用发电机励磁和调速系统的数学模型及参数

现场调查了华中、川渝系统典型的200MW及以上汽轮发电机、100MW及以上水轮发电机励磁系统模型及参数、调速系统(包括原动机)模型及参数;总结了现场进行发电机励磁系统参数测试的经验;根据现场实测结果和调查结果确定发电机励磁控制系统、调速系统可用于电力系统稳定计算的数学模型及参数;提出了评判、校核基于现场测试得出的数学模型和参数正确性的方法,并将其应用到指导生产的仿真计算之中取得了一定的成果。     

华中–川渝联网稳定计算用发电机励磁和调速系统的数学模型及参数

现场调查了华中、川渝系统典型的200 MW及以上汽轮发电机、100 MW及以上水轮发电机励磁系统模型及参数、调速系统(包括原动机)模型及参数；总结了现场进行发电机励磁系统参数测试的经验；根据现场实测结果和调查结果确定发电机励磁控制系统、调速系统可用于电力系统稳定计算的数学模型及参数；提出了评判、校核基于现场测试得出的数学模型和参数正确性的方法，并将其应用到指导生产的仿真计算之中取得了一定的成果。     

稳定计算用励磁系统数学模型仿真建模研究

结合当前电力系统的实际需要,提出了稳定计算用励磁系统数学模型仿真建模及参数校核方法。以实际工程为例,详细分析了仿真建模的过程,确定了稳定计算用的励磁系统模型和参数,为系统稳定分析及电网日常生产调度提供了准确的依据。     

发电机励磁系统参数测试及仿真

通过参数收集、现场试验和计算分析,得到准确的发电机及励磁系统参数,再使用发电机详细模型进行PSASP仿真校验,比较原始参数与实测参数对模型仿真的影响,进而获得符合实际的模型及参数,结果可用于电力系统稳定计算,提高计算分析的准确度。     

台州电厂7、8号发电机励磁系统模型参数

依据台州电厂７、８号机现场辩识、测量数据和制造厂资料构成励磁系统模型（包括励磁限制、调差和ＰＳＳ），确定参数。对此模型以及制造厂提供的模型进行空载阶跃仿真计算，与现场实测的响应进行比较验证，推荐供分析用的模型参数。     

大坝电厂#4机励磁系统数学模型参数测试

通过对大坝电厂#4机组励磁系统参数实测,建立了电力系统稳定计算用励磁系统的数学模型。并确定了模型参数,现场运行实践和稳定对比计算表明,所建模型及参数能满足系统稳定运行的要求。具有一定的参考价值。     

实测励磁系统模型和参数对电力系统稳定极限计算的重要性

发电机励磁系统模型和参数的准确性对电网稳定极限的计算影响很大，在没有实测模型和参数的情况下，通常只能采用典型的模型和参数进行计算，这样计算得到的稳定极限和电网的实际稳定极限可能会有很大的误差。本文对某电网一个电厂的励磁系统分别采用典型模型、参数和实测模型、参数计算的稳定情况进行了比较，以此说明对发电机励磁系统模型和参数进行实测的重要性。     

暂态稳定分析典型励磁模型仿真研究

在电力系统运行中,发电机励磁系统的电压调节特性和强励性能对整个系统的稳定运行有重要影响,为深入认识该特性和与之相关的影响因素,以IEEE Std 421.5-1992标准推荐的交流励磁机励磁系统和静止励磁系统为基础,构建了单机-无穷大网络数值模型和励磁控制数值模型,交流励磁机励磁系统主要包括AC1～AC6 6种模型,静止励磁系统主要包括ST1～ST3 3种模型。励磁系统主要考察发电机在额定转速解裂运行方式下的90%额定电压起励特性、10%阶跃响应特性和在并网额定运行方式下三相短路故障后的励磁电压动态调节特性,比较了不同励磁模型在相同工况下的控制品质和对系统稳定运行的影响,分析了励磁强励特性的影响因素。     

计及风电随机激励的电力系统暂态稳定分析

为了探讨风电随机激励对电力系统暂态稳定的影响,提出一种基于随机微分理论对含风电电力系统进行建模和稳定分析的方法。首先将异步风机机械功率作为随机激励,在暂态过程中利用伊藤型随机微分方程对异步风机的转子运动方程进行建模,将传统的微分代数方程模型扩展成随机微分代数方程模型;然后针对新的模型,通过时域仿真进行求解,分析风电功率随机波动对电力系统暂态过程的影响。算例结果表明:相比于确定性和概率性暂态稳定分析方法,所提方法能够更好地揭示风电不确定性对电力系统暂态稳定性的影响。     

Sensitivity analysis in power system dynamic stability studies

The stability limits for power systems can be defined by curves on the capability chart. In this paper the sensitivity of these curves versus system parameter perturbations is considered. The results also look interesting from a practical point of view, since a more realistic and efficient margin for stability can be defined. On this basis, the margin variations due to parameter perturbations are determined. Finally, a useful criterion is introduced to determine globally the influence of the parameter perturbations on the dynamic behaviour of the system.     

Analysis and assessment of VSC excitation system for power system stability enhancement

The voltage source converter (VSC) excitation system is a novel excitation system based on pulse-width modulation (PWM) voltage source converter, which is proposed as improved alternatives to the conventional thyristor excitation systems. This paper aims to provide theoretical confirmation of power system stability enhancement by the VSC excitation system. The reactive current injected to generator terminals by the VSC excitation system can be controlled flexibly. Its capability of enhancing power system stability is investigated in this paper. The simplified model of VSC excitation system suitable for use in system stability studies is developed. An extended Philips–Heffron model of a single-machine infinite bus (SMIB) system with VSC excitation system is established and applied to analyze the damping torque contribution of the injected reactive current to the power system. This paper also gives a brief explanation on why the VSC excitation system can enhance the transient stability in light of equal area criterion. The results of calculations and simulations show that the injected reactive current of VSC excitation system contributes to system damping significantly and has a great effect on the transient stability. When compared with conventional thyristor excitation systems, the VSC excitation system can not only improve the small-signal performance of the power system, but also can improve the system transient stability limit.     

Damping representation for power system stability studies

The paper includes a review and summary of the actual damping in electric power systems and the methods for modeling such damping in the various computer programs used to study power system stability. It is concluded that great care is required in both software development and program application to avoid serious errors in the study of power system stability. Judgment is often required for reasonable modeling of damping. Recommendations are provided to guide the power system stability practitioner, and research activities are recommended     

励磁放大倍数对系统电压稳定性的影响研究

搭建单机无穷大动态系统,基于分岔理论,研究随着负荷参数的改变,不同励磁放大倍数Ka对系统电压稳定性的影响。研究结果表明,随着Ka的增大,系统分岔点数目会减少,且极值分岔将延迟出现。但Ka不是越大越好,过大的Ka会增加系统Hopf分岔,容易造成系统电压振荡,不利于系统电压稳定性。基于PSASP的时域仿真也得到相同的结果,说明采用高放大倍数的励磁调节器在提高励磁效率的同时,还需要通过调节器的限制和保护来实现其稳定运行。     

ObjectStab-an educational tool for power system stability studies

Traditionally, the simulation of transient and voltage stability in power systems has been constrained to domain-specific tools such as Simpow, PSS/E, ETMSP, and EuroStag. While being efficient and thereby able to simulate large systems, their component models are often encapsulated and difficult or impossible to examine and modify. Also, these simulators often require substantial training and are therefore not ideal for normal classroom use. For academic and educational use, it is more important that the component modeling be transparent and flexible, and that students quickly get started with their simulations. This paper describes a freely available power system library called ObjectStab intended for power system stability simulations written in Modelica, a general-purpose object-oriented modeling language. All component models are transparent and can easily be modified or extended. Power system topology and parameter data are entered in one-line diagram form using a graphical editor. The component library has been validated using comparative simulations with EuroStag.     

电力系统暂态稳定性数值计算的几种新方法及其比较

将辛几何算法及辛代数动力学算法两类新的方法引入电力系统暂态稳定性数值计算.以一个简单的电力系统为例,通过数值实验将新方法与电力系统分析中常用的隐式梯形积分法及传统的Runge-Kutta方法进行了对比分析.初步的数值实验结果表明,辛几何算法及辛代数动力学算法与传统算法相比,在计算精度和数值稳定性方面具有较为明显的优势,因而更适合于电力系统暂态稳定性及相似问题的数值计算.     

A stability measure for use in power system transient stability studies

Large system transient stability calculations may be carried out using network equivalents, and generator grouping, and by reducing the order and complexity of the system representation. Engineering judgement and, in most cases, prior knowledge of transient system performance is required to implement the models.In this paper a new parameter called ‘stability measure’ is introduced. The stability measure can easily be calculated on the basis of load flow and short-circuit results. Upon calculation of the stability measure set for a given fault condition, an estimate of the likely response of the respective generators to the fault is obtained.The validity and generality of the stability measure has been demonstrated by simulated tests on a sample power system.Application of the method with respect to grouping of generators in transient stability studies is also discussed.