Performance Of Electric Power Systems Research Articles

Performance of Electric Power Systems in the 2010–2011 Christchurch, New Zealand, Earthquake Sequence

From late-2010 to mid-2011, Christchurch suffered a series of earthquakes and aftershocks that affected the city's power supply. The most relevant of these events occurred on 4 September 2010, 22 February 2011, and 13 June 2011. In all these events transmission level power restoration occurred rapidly—within one day. Except for the second event, similar relatively minor damage led to rapid restoration of distribution-level power outages. However, extensive damage to underground cables during the February 2011 earthquake caused some outages that lasted until early March. This damage seems to be amongst the only extensively-documented such failures to date. Despite recorded strong ground shakings, damage to other power infrastructure facilities was moderate to minor. This satisfactory performance of power infrastructure is attributed to a program implemented during the decade prior to this earthquake sequence to seismically upgrade almost all unreinforced masonry substation buildings and reinforce other infrastructure elements.

Simulation Model of Brushless Excitation System

Excitation system is key element in the dynamic performance of electric power systems, accurate excitation models are of great importance in simulating and investigating the power system transient phenomena. Parameter identification of the Brushless excitation system was presented. First a block diagram for the EXS parameter was proposed based on the documents and maps in the power station. To identify the parameters of this model, a test procedure to obtain step response, was presented. Using the Genetic Algorithm with the Matlab-software it was possible to identify all the necessary parameters of the model. Using the same measured input signals the response from the standard model showed nearly the same behavior as the excitation system.

Simulation Model of Brushless Excitation System

Excitation system is key element in the dynamic performance of electric power systems, accurate excitation models are of great importance in simulating and investigating the power system transient phenomena. Parameter identification of the Brushless excitation system was presented. First a block diagram for the EXS parameter was proposed based on the documents and maps in the power station. To identify the parameters of this model, a test procedure to obtain step response, was presented. Using the Genetic Algorithm with the Matlab-software it was possible to identify all the necessary parameters of the model. Using the same measured input signals the response from the standard model showed nearly the same behavior as the excitation system.

Application of Instrumentation for the Evaluation of Power System Dynamic Performance

The dynamic performance of electric power systems during disturbances is a function of many factors. The effect of these factors vary with the nature and configuration of the electrical system and is complicated due to the interrelated, and sometimes compounding effect of the automatic control equipment which makes up a system. The post-event evaluation of a dynamic system condition requires automatic and instantaneous recording of many system quantities which will show initial conditions, the transient period, the dynamic period, and the steady state or final result of all contributing factors. The instrumentation required to monitor the influence of various system quantities must provide precise records even though separated by great distances and must continue to perform accurately regardless of wide variations in voltage, current or frequency.

Aircraft Electric Power System Performance as Affected by Transmission Line Impedances

The electric power transmission lines on large jet aircraft must be selected with the power system performance characteristics in mind as well as the conductor current carrying capabilities. Trade-offs between total system weight and system performance may be considered where long transmission lines are required. The main areas of performance that would be affected are system voltage transients, system ceiling voltage, system voltages during unbalanced load conditions and system protection.