Service Restoration Following a Major Failure on the Hydro-Québec Power System

Abstract

Service restoration following a major power failure can occasion voltage problems on weak EHV systems from the point of view of both steadystate and temporary operation. This is due to the use of long EHV transmission links between the production sites and the load centres, which can cause large amounts of reactive power to be generated, and low short-circuit level, leading to low-frequency resonance, further excited by the presence of transformers. This paper describes an approach to service restoration which should speed up the process of restoring service to customers while at the same time limiting the risks of damage to equipment.

Using artificial neural network to analyze harmonic overvoltages during power system restoration

“…Figure 11 shows voltage at bus 2 after transformer switching for the worst-case condition (i.e., switching angle 788 and remanent flux 0.64 p.u.). For TOVs, the overvoltage duration has to be taken into account in addition to the amplitude [8]. Table I summarizes the results of overvoltages simulation for four different switching angle and remanent flux that verify the effectiveness of W index.…”

“…This leads to a higher level of saturation, resulting in higher harmonic components of the inrush current that again results in increased voltages. This can happen particularly in lightly damped systems, common at the beginning of a restoration procedure when a path from a black-start source to a large power plant is being established and only a few loads are restored yet [1,8,9].…”

Estimation of Temporary Overvoltages during Power System Restoration using Artificial Neural Network

“…This leads to a higher level of saturation, resulting in higher harmonic components of the inrush current that again results in increased voltages. This can happen particularly in lightly damped systems, common at the beginning of a restoration procedure when a path from a black-start source to a large power plant is being established and only a few loads are restored yet [2], [8].…”

Primary Restoration Path Selection Considering Ferranti Effect and Reactive Power Capability of Black-start Generators

“…Although restoration strategies are slightly different in each country as restoration methods are dependent on faults, voltage levels, structures of transmission grid, and equipment of its own power system, it is clear that during the first stage of restoration, Black-Start Generators (BSGs) that are usually hydro type in Korea, should supply cranking power to Primary Supplied Generators (PSGs) having big capacity through so called primary restorative transmission lines in case of wide area blackout [1][2][3][4][5][6].…”

“…Morin [12] and Huang [13] showed voltage profile of PRT lines considering picking-up loads, and Adibi [14] showed quantitative Reactive Capability Limitation (RCL), but did not consider generator pole type.…”