Time/Frequency Approach to Phasor Dynamics in Power Systems Analysis

电力系统分析中相量动力学的时间/频率方法

• 批准号: 9527570
• 负责人: Christopher DeMarco
• 金额: $ 11.78万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-15 至 1999-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9527570&HistoricalAwards=false
• 关键词: Time; Frequency; Approach; Phasor; Dynamics

9527570 DeMarco Dynamic studies in power systems have long exploited analytic simplifications gained by approximating all voltages and currents in the network as sinusoids of "slowly varying" magnitude and phase. With this assumption, network behavior in dynamic analyses is characterized by power flow equations that represent time-domain bus voltages via complex phasors. This is typically referred to as the "sinusoidal quasi-steady-state" approximation (abbreviated here by the acronym "SQSS"), and is widely utilized in modern computer packages used to study electromechanical behavior and control system dynamics. For faster time-scale phenomena, the most widely used techniques are time-domain simulations in which all relevant network voltages and currents are represented as three-phase, time-domain signals, without any requirement of nearly sinusoidal behavior. This latter approach involves tremendous computational burden and analytic complexity, because one uses instantaneous quantities rather than phasors, and dynamic circuit models rather than algebraic impedance relations. The goal of the research outlined in this proposal is to provide a middle ground between the approximations inherent in an impedance-based SQSS representation, and the analytic complexity and computational burden associated with representing network voltages and currents as time-domain quantities in a three-phase circuit. In particular, this work will adopt a viewpoint on phasors that is closer to time/frequency representations utilized in signal processing, but extending these representations to a dynamic formulation. The result will be termed "Phasor Dynamics" (PD) models, and will involve a carefully constructed hybrid of the impedance and circuit representations. This approach will allow an important extension that is not possible in standard phasor representations: a dynamic analysis that includes higher order harmonics. The work proposed will treat these cases by representing relevant st ates as weighted sums of narrow-band signals, each located about a harmonic center frequency of interest. The time evolution of the weights are governed by dynamic equations derived directly from the original instantaneous model. ***

小行星9527570 长期以来，电力系统的动态研究一直利用分析简化，将网络中的所有电压和电流近似为幅度和相位“缓慢变化”的正弦曲线。 在此假设下，动态分析中的网络行为由通过复相量表示时域母线电压的潮流方程表征。 这通常被称为“正弦准稳态”近似（这里缩写为“SQSS”），并广泛用于现代计算机软件包，用于研究机电行为和控制系统动态。 对于更快的时间尺度现象，最广泛使用的技术是时域仿真，其中所有相关的网络电压和电流都表示为三相时域信号，而不需要接近正弦的行为。 后一种方法涉及巨大的计算负担和分析复杂性，因为使用瞬时量而不是相量，动态电路模型而不是代数阻抗关系。 在这个建议中概述的研究的目标是提供一个中间地带之间的近似固有的基于阻抗的SQSS表示，和分析的复杂性和计算负担与代表网络电压和电流作为时域量在三相电路。 特别是，这项工作将采用相量的观点，更接近信号处理中使用的时间/频率表示，但这些表示扩展到一个动态的配方。 结果将被称为“相量动态”（PD）模型，并将涉及一个精心构建的阻抗和电路表示的混合。 这种方法将允许一个重要的扩展，这是不可能在标准相量表示：一个动态分析，包括高阶谐波。 所提出的工作将处理这些情况下，代表相关的国家作为窄带信号的加权和，每个位于一个谐波中心频率的利益。 权值的时间演化由直接从原始瞬时模型导出的动态方程控制。 ***