Dynamic Modelling and Control Design of Advanced Energy Storage for Power System Applications

In general, a large percentage of the electric power produced is generated in huge generation centres far from the consumption, and with centralized transmission and distribution systems, where the weak point of this scheme is the efficiency with high energy losses in the form of heat. This problem has been increased in the last years due to the significant growth of electric energy demand and in the case of structures of weakly meshed electrical grids, due to the high vulnerability in cases of faults that can originate frequently severe transient and dynamic problems that lead to the reduction of the system security (Dail et al., 2007). Many large blackouts that happened worldwide in the last decade are a clear example of the consequences of this model of electric power. These problems, far from finding effective solutions, are continuously increasing, even more impelled by energy factors (oil crisis), ecological (climatic change) and by financial and regulatory restrictions of wholesale markets, which causes the necessity of technological alternatives to assure, on one hand the appropriate supply and quality of the electric power and on the other one, the saving and the efficient use of the natural resources preserving the environment. An alternative technological solution to this problem is using small generation units and integrating them into the distribution network as near as possible of the consumption site, making this way diminishing the dependence of the local electrical demand, of the energy transmission power system. This solution is known as in-situ, distributed or dispersed generation (DG) and represents a change in the paradigm of the traditional centralized electric power generation (El-Khattam & Salama, 2004). In this way, the distribution grid usually passive is transformed into active one, in the sense that decision making and control is distributed and the power flows bidirectionally. Here it is consolidated the idea of using clean non-conventional technologies of generation that use renewable energy sources (RESs) that do not cause environmental pollution, such as wind, photovoltaic (PV), hydraulic, biomass among others (Rahman, 2003). At present, perhaps the most promising novel network structure that would allow obtaining a better use of the distributed generation resources is the electrical microgrid (MG) (Kroposki et al., 2008). This new paradigm tackles the distributed generation as a subsystem formed by distributed energy resources (DERs), including DG, RESs and distributed energy storage (DES) and controllable demand response (DR), also offering significant control