Monitoring Subsynchronous Oscillations in Power Systems using Synchronised Measurement Technology
This paper studies the performance of several commercial PMUs and a fault recorder when used to monitor Subsynchronous Oscillations (SSO) in a laboratory.An Omicron CMC256 is used to inject signals into these devices,the outputs are captured using a data concentrator and analysed in Matlab.The study uses constructed signals (Matlab) to understand the behaviour of each device for specific conditions.The ability of each device to accurately monitor SSO and the extent to which out of band SSO will degrade the performance of a PMU is studied.The monitoring of SSO is relevant because Series Compensation (SC) is a cost effective tool for increasing the capacity of existing transmission networks but introduces the risk of Subsynchronous Resonance (SSR) that can cause significant damage to generating plant. Whilst Thyristor Controlled Series Compensation (TCSC) has been shown to be SSR neutral, the increasing levels of power electronics (PE) in power systems increases the risk of Subsynchronous Interactions (SSI). These interactions may require a redefinition of SSR, as PE lacks the distinguishable torsional modes that exist for turbine-generator shafts. Therefore, using traditional, electromagnetic offline studies to address these new forms of SSR may prove challenging and time consuming, in the absence of the well-established benchmark models, theory and experience that exists for classical SSR. Using Wide Area Monitoring Systems (WAMS), based on Synchronized Measurement Technology (e.g. PMUs), for the online monitoring of SSO could create a valuable tool for the real time detection of dangerous oscillations that does not require extensive offline studies, new models or system/device data. However, developing such a tool would require a full understanding of the response of sensors in the presence of SSO and prior to its practical deployment the vulnerabilities of a measurement based solution would need to be considered, e.g. guaranteeing sufficient observability. Phasor Measurement Units (PMUs) form the basis of WAMS and typically have a maximum reporting rate of once per cycle (50/60 Hz), so the theoretical limit on the highest frequency SSO they can accurately report is 25/30 Hz. Whilst this limits the ability of a PMU to report the full range of SSO, a more critical issue is that the accuracy of the PMU could be compromised if it fails to reject out-of-band signals. This may pose a challenge for modern power systems, as many utilities are increasingly using WAMS based solutions to improve system operation. Whilst the C37.118.1a-2014 standard does provide requirements for the rejection of SSO, WAMS installation is a long term process; so, many PMUs may not comply with the most recent standards. Devices with a higher reporting rate can be used to capture the full range of SSO. This study includes a synchronised fault recorder that reports waveform samples at a rate of 200 Hz.
Fault Recorder Phasor Measurement Units Subsynchronous Oscillations Subsynchronous Resonance Synchronised Measurement Technology WAMPAC Wide Area Monitoring
P. WALL P. DATTARAY A. NECHIFOR V. TERZIJA
The University of Manchester United Kingdom
国际会议
国际大电网会议组织保护与自动化专业委员会年度会议暨学术研讨会
南京
英文
1-6
2015-09-20（万方平台首次上网日期，不代表论文的发表时间）