Fast Power System Restoration via Load Shedding Practices in the Egyptian Power System.

Document Type : Research Studies

Authors

1 Assistant Professor., National Energy Control., Center of Egypt.

2 Assistant Professor., Electrical Power Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., Egypt.

3 Talkha Power Station.

Abstract

This paper investigates the dynamic stability of power systems due to disturbances of finite magnitude that last for some minutes. In this paper the effect of only active power deficits is investigated. A computer program is developed to discuss system frequency changes during such disturbances. The program implements a practical approach using an energy aproach and gives an insight to the following issues : 
(i) hydro spinning reserve is modelled as a function of frequency deviations, while thermal reserve is independent of frequency deviations.
(ii) hydro and thermal spinning reserves are modelled as a function of frequency deviations.
 (iii) load shedding modelling in steps to trip loads as the frequency decreases.
 This approach is applied to the Egyptian power system using the load shedding scheme adopted in the system. Three case studies, each case is studied for twelve active power deficits ranging from 150 MW to 1800 MW during three loading conditions (minimum day, maximum day and maximum evening). The results represent three scenarios for system restoration, the first one neglects the effect of spinning reserve, while the second and third ones implement the utilization of spinning reserve as mentioned here above.

Main Subjects