Automatic load shedding scheme and the integration of new capacitors’ controller in the South-West region of France to mitigate large scale voltage collapses

Abstract: Since the modern world is totally dependent on electricity, it is necessary to ensure that electrical power is generated and transmitted to end users with minimum interruptions. Given the importance of electricity for the operation of our society, it is really important to fill continuously good safety conditions. This policy must handle two major areas: reducing the risk of occurrence of a crisis and its management if a very constraining disturbance happens. This master’s thesis is mainly focused on this last point. With the continuous increasing of consumption and the high investment costs, it becomes more complicated to ensure good safety margins, since the network is exploited closer to its limits. A recent study demonstrates that the South-West region of France was prone to voltage collapses after very severe faults and as a result the need of an under-voltage load shedding in this region was evokated. In parallel, to ensure the voltage stability, RTE (Réseau de Transport d’Electricité - Electricity Transmission Network) has invested also in equipments such as capacitors and static reactive power compensators. With newly installation of compensation means on the network, the necessity to develop a new device called SMACC (Système avancé pour le contrôle de lacompensation - Advanced system for the control of the compensation) capable of handling more efficiently the control of these batteries of capacitors has been highlighted. Ultimately the thesis focuses also on the new HVDC (High-voltage direct current) line between France and Spain. This line is a key for long-term voltage stability study, since itincreases the exchange capacity between France and Spain, and has the ability to provide or absorb reactive power to the network.