International Journal of Computer Applications (0975 – 8887) Volume 66– No.8, March 2013 27 The Behavior of the Algerian Network after the Loss of a VHV Substation Bouchahdane Mohamed Département d’Electrotechnique Laboratoire d’Electrotechnique de Constantine Université Mentouri – Constantine (Algérie) Bouzid Aîssa Département ’Electrotechnique Laboratoire d’Electrotechnique de Constantine Université Mentouri – Constantine (Algérie) ABSTRACT Maintaining consistency in terms of electricity supply capacity should be the aim of any research in this area. Hence the concern of maintaining the stability of this great production-transport-distribution system, even when low probability major disruptions is to occur. The study of the operation of the national grid shows that it is adequately equipped to cope with such disruptions. Thus, the oscillations observed at that level are quickly reduced and hence the interconnected system maintains synchronization in case of loss of a VHV substation. Keywords Electrical network; protection; electrical interconnection; loss of synchronism; stability 1. INTRODUCTION Several factors, both endogenous and exogenous, push the whole system with its different components to its limits of stability. Increasing loads, distances between the various centers of production, the state of transmission and consumption centers are the most notable. In these cases, power outages damaging for both for operators and consumer, may occur. [1] [2] In this paper we describe a case study carried out at the level of the Department for Study and Forecast of the STATE COMPANY OF ELECTRICITY AND GAS (SONELGAZ) which includes the Algerian National Dispatching. The purpose of this paper is to show that the simulation of the loss of VHV substation determines the interconnections VHV substation role in improving the quality of service for the national network. [3] [4] We would underline the importance of the present work on its application at any kind of renewable energy sources dotted with its proper substation connected to the main network. As the Algerian network is itself integrated to a higher network (the Mediterranean network), our present study is applicable to the whole. 2. IMPORTANCE OF THE ELECTRICAL NETWORK PROTECTION FOR ENERGY SUPPLY A relay showing a faulty behavior can lead from a failure of some consumers to reach the population of an entire city, including sensitive facilities such as hospitals, fire etc .... In case of a power outage of about 10 MW for a duration of 6 minutes it won’t only mean a loss of 1MWh unsold energy, but several hours necessary for the manufacturer to restart. But it is mainly a disgruntled consumer who would have lost many hours of production or even in some cases an irreversible loss of some of his equipment consequently to this incident. [5] [6] 3. STUDY AND ANALYSIS OF OPERATION OF 400KV NETWORK 3.1 The SICRE Simulator The purpose of the SICRE program is to provide the larger numbers of users with useful tools for analyzing, monitoring and training. It includes a set of simulation functions and analysis that can represent the dynamic behavior of power systems on different time scales in both normal conditions in emergency situations. From the point of view of its components modeled to a high degree of accuracy, the kit is fairly complete in that it shows the efficiency of algorithms as it is designed, based on the most advanced SW/HW technologies. Main application fields of SICRE: 3.1.1 Analysis and control Evaluation of the overall performance of the system through dynamic analysis and daily control during planning and operational stages of functioning. .Reconstitution of serious incidents to better understand the dynamic of phenomena and events and to check the system components (protections, controllers, etc ...) and behavior. Design and verification of new automatic defense actions to avoid incidents that have already occurred, or prevent further coming incidents or limit and / or master their consequences. Checking restoration procedures. 3.1.2 Training Simulation of scenarios aim at improving the comprehension of dynamic phenomena for training sessions addressed to system engineers and CC operators. Simulation of scenarios of emergency conditions or restoration phases for accustoming operators to face critical operating conditions.