Research on forced oscillations disturbance source locating through an energy approach

Abstract

Summary Low‐frequency oscillations (LFOs) are inherent phenomena of modern interconnected electrical power systems, essentially caused by the continuous exchange of momentum among rotating masses. It is widely recognized that LFOs can be induced by both the occurrence of multiple disturbances and the existence of periodic disturbance sources. LFOs can be classified into negative damped oscillations and forced power oscillations. The former can be suppressed by standard controllers (e.g., power system stabilizers). The latter cannot be eliminated until the disturbance source is removed or isolated. Thus, locating the forced disturbance source promptly and accurately is crucial. In this paper, a traditional energy function, simplified and improved, with a new decomposition way to show the direction of energy flow is proposed. Energy associated with the LFO is decomposed into oscillating component and quasi‐steady component at the aim of analyzing the inducing multiple disturbances. The branch energy is hence decomposed into periodic and aperiodic components. By identifying the direction along which the aperiodic component is propagated and dissipated, the periodic forced disturbance source could be located rapidly and accurately. The proposed energy decomposition method provides a novel idea to judge the direction along which the dissipated energy flows. The effectiveness and feasibility of the proposed method were verified by simulation results obtained on an actual large‐scale interconnected power grid in China. Copyright © 2015 John Wiley & Sons, Ltd.

Location methods of oscillation sources in power systems: a survey

“…Another phenomenon called the concentric relaxation is introduced in [51] for power systems under forced oscillations, which could help avoid the erroneous location results. To date, this category of methods has been largely applied to power systems in the past five years [52][53][54][55][56][57][58][59][60][61][62][63].…”

Application of unknown input observers to locate forced oscillation source

“…Besides poorly damped oscillation, it is well recognized that there is another common type of low‐frequency oscillation, known as forced oscillation. Extensive research has been reported on the subject …”

“…More specifically, methods for locating forced oscillation sources are proposed recently in the literatures . Wang and Sun gives a comprehensive review of the location methods and elaborates on their advantages and disadvantages.…”

“…Wang and Sun gives a comprehensive review of the location methods and elaborates on their advantages and disadvantages. Typical existing methods can be mainly summarized as hybrid simulation method, energy‐based methods, damping torque methods, mode shape estimation methods, effective generator impedance method, etc. Ma et al introduces a model‐based method using hybrid dynamic simulation to locate oscillation source, which combines dynamic simulation and measured PMU data.…”

“…Resistances in loads may also produce transient energy like oscillation sources, which may cause misinterpretation . Tang et al, Maslennikov et al, and Feng et al have developed the classic energy‐based method into more robust methods and achieved more detailed location results. A model‐based method which uses effective generator impedance to locate oscillation source is proposed in Chevalier et al It represents a source generator as an effective admittance matrix and an effective current source.…”