Wind farms participation at voltage and reactive power regulation in the power system network

Nowadays, wind farms integration is significantly increasing in the distribution and transmission networks. It seems necessary to involve the wind farms in voltage and reactive power management in the power systems. For the aforementioned purpose, the wind power producers and the power grid operators should perform a reconfiguration and adaptation of their actual supervision and control systems. In this PhD dissertation, we propose various voltage and reactive power regulation algorithms for different connection types of the wind farm to the power network. Three connection types are considered here: a wind farm connected directly to the distribution network, dispersed wind turbines connected to the distribution network and a set of wind farms connected to the transmission system. As a pre-process, the reactive power reserve of different wind turbine types are presented by PQ diagram. Based on these diagrams and the bus voltage constraints inside the wind farm, the reactive power reserve of a wind farm is introduced by another PQ diagram. A closed loop controller (Wind Farm Controller) is proposed in case of a directly connected wind farm to the distribution network. A coordinated voltage control in the presence of on load tap changer (D-CVC) is proposed in case of dispersed wind turbines connected to the distribution network. We also propose a more decentralized version of D- CVC named D2-CVC; this version can be also implemented under multi-agent system (MAS). A multi-level control system is proposed in case of a set of wind farms connected to the transmission system. It allows the wind farms to optimally participate at reactive power balancing in transmission network. All the proposed voltage algorithms are based on a multi-objective optimization function. The experimental implementation of these regulation algorithms is run under RT-Lab real-time simulator. It allows validating their real-time operation and their communication modes before the implementation on a real site. The results of the current thesis show the improvement of distributed generation integration in the power system network. (author)