Optimal Control on Electrical Substation for Enhanced Stability Transient Considering Frequency and Voltage

Smart grid is a fast-growing technology, and this growth implies an enormous demand for better modelling and control. Non-linear behaviour and uncertainties represent for control a challenging task to overcome. These considerations drive the lack of advanced modelling and further development of optimal control strategies, with the primary aim of maximising the energy efficiency. The research proposes an optimal approach for network layout and control for a smart grid electrical substation with photo-voltaic generation. The optimisation method relies on heuristics and hierarchical control, minimising the network length and the steady state error. Smart power substation is the name for the planned scheme. The network layout is multi-layered and bases on heuristic algorithms. The first and second layer routes underground geo-reference electrical networks, which minimises network length. Maximising the power quality, the network reliability and reducing the implementation cost. The third layer optimally allocates the photo-voltaic rooftop panels with a geo-reference criterion. Hierarchical control appears from the primary controller, which controls the current and the voltage outputs. The secondary control regulates the references for voltage amplitude and frequency, which based on the expected active and reactive power. Finally, the tertiary control deals with energy management and dispatching, which implements a communication coordination among the individual controllers. The cost functions determine the optimal coefficients values for each individual controller to reduce the steady state error. For this purpose, the investigation tests several performance indices to notice which reach the less error, like as integral square error indices methods. The system steady state is over-damped, and it has not over-shoot. However, it has a 5% of oscillations around the desired voltage level, which keep a constant pattern. The response time is fast, considering the non-linear elements behaviour and the multiple system interactions. Hence, the establishing time is less than 0.4 seconds where, despite the increase in load, the system output satisfies the system’s requirements in terms of power and voltage.