Abstract
The objective of this paper is to analyse the steady state and dynamic behaviour of a MicroGrid system containing one microturbine generating Combined Heat and Power feeding some small local loads in islanded mode of operation. Future operating scenarios were also analysed and simulated, namely considering the installation of photovoltaic panels near consumers.

Abstract
This paper describes and evaluates the feasibility of control strategies to be adopted for the operation of a microgrid when it becomes isolated. Normally, the microgrid operates in interconnected mode with the medium voltage network; however, scheduled or forced isolation can take place. In such conditions, the microgrid must have the ability to operate stably and autonomously. An evaluation of the need of storage devices and load shedding strategies is included in this paper.

Abstract
In general, distributed generation is not subject to a centralized dispatch and reactive power generation is usually restricted by operation rules defined by the distribution system operators. With the growth of distributed generation and microgrids in distribution networks, the development of voltage control functionalities for these units needs to be investigated. This requires a new operation philosophy to exploit reactive power generation capability of distributed generation and microgeneration with the objective of optimizing network operation: minimize active power losses and maintain voltage profiles within adequate margins. This implies that distributed generation should adjust their reactive power generation, i.e. supply an ancillary service of voltage and reactive power control. In addition to the growth in distributed generation penetration, microgeneration is expected to develop considerably and contribute to the implementation of efficient voltage control schemes. For this new scenario, a hierarchical voltage control scheme must be implemented, using communication and control possibilities that will be made available for microgrid operation. Technical advantages and feasibility of this operation philosophy are investigated in this chapter by analyzing the impact of the proposed control procedures on distribution networks. In addition, the identification of control action needs is assessed by solving an optimization problem, where voltage profiles are improved and active power losses minimized, subject to a set of technical constraints. The solution for this problem is obtained using an Evolutionary Particle Swarm Optimization algorithm. The control algorithm implemented will enable dealing even with extreme situations, where reactive power control is not sufficient to maintain system operation and therefore generation shedding actions must be performed.

Abstract

Abstract
The main objective of this paper is to present the development of microsource modelling and the definition of control strategies to be adopted to evaluate the feasibility of operation of a microgrid when it becomes isolated. Normally, the microgrid operates in interconnected mode with the MV network, however scheduled or forced isolation can take place. In such conditions, the microgrid must have the ability to operate stably and autonomously. An evaluation of the need of storage devices and load-shedding strategies is included in the paper.

Abstract
This paper presents a novel architecture for electrical distribution networks based on a decentralized control system where a Substation Automation and Control System plays a key role. This new control element brings additional control and management functionalities that are crucial for future distribution networks with high levels of Dispersed Energy Resources in both interconnected and islanded operating modes. Several coordination and control issues are addressed with the aim of optimizing grid operation in interconnected mode and simulation results are shown for voltage and reactive power control.