Communication based loss-of-mains protection method by frequency correlation

  • Ahmed Adnan Makki

Student thesis: Master's Thesis

Abstract

Due to the increasing penetration of distributed generation (DGs) in the distribution network in high numbers and proportions, and its conspicuous impact on power system stability. This occurs during a wide system disturbance in the power system, the DGs will start to disconnect from the main source in large proportions. This will further affect the power system stability and causes damages to its components and DGs. This thesis investigates in the reliability, security, and efficiency of satellite and internet communications, specifically for loss of mains (LOM) protection and exploring the strengths, the weaknesses, the feasibility of each type of communications, and the requirements of communication system components. By using communications network to send Phasor Measurement Unit (PMU) data to DGs protection equipment that are connected at remote areas all over UK, the LOM protection can be improved, obtain synchronization, precision, and coordination among power protection components. Satellite communication is chosen as it makes a better communication method when it comes to the installation, construction, urban disruption, time saving, and the installation and annual cost on every participant. However, the high latency issue is approached and solved by making a few changes in the communication protocol format and the data requirements to reduce the effect of latency to a level that can be tolerated. This thesis presents the development of a novel LOM protection method based on communication and frequency correlation. The stability and sensitivity assessment will show that this method is highly secure and reliable. It can also withstand a communication delay of 120ms without causing any nuisance tripping, and have a relay response to LOM operation of a maximum of 1s. The thesis also presents a novel method in time delay estimation that has been developed for power system applications.This method is called the Linear Trajectory Path (LTP) and its performance fulfils the LOM synchronisation requirements by succeeding in determining the time delay between the two data streams within the tolerated estimation error of ±100ms.
Date of Award1 Jun 2014
LanguageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsEPSRC (Engineering and Physical Sciences Research Council) & University of Strathclyde
SupervisorAdam Dysko (Supervisor) & Campbell Booth (Supervisor)

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