Computational intelligence approaches for energy load forecasting in smart energy management grids: state of the art, future challenges, and research directions and Research Directions

Energy management systems are designed to monitor, optimize, and control the smart grid energy market. Demand-side management, considered as an essential part of the energy management system, can enable utility market operators to make better management decisions for energy trading between consumers and the operator. In this system, a priori knowledge about the energy load pattern can help reshape the load and cut the energy demand curve, thus allowing a better management and distribution of the energy in smart grid energy systems. Designing a computationally intelligent load forecasting (ILF) system is often a primary goal of energy demand management. This study explores the state of the art of computationally intelligent (i.e., machine learning) methods that are applied in load forecasting in terms of their classification and evaluation for sustainable operation of the overall energy management system. More than 50 research papers related to the subject identified in existing literature are classified into two categories: namely the single and the hybrid computational intelligence (CI)-based load forecasting technique. The advantages and disadvantages of each individual techniques also discussed to encapsulate them into the perspective into the energy management research. The identified methods have been further investigated by a qualitative analysis based on the accuracy of the prediction, which confirms the dominance of hybrid forecasting methods, which are often applied as metaheurstic algorithms considering the different optimization techniques over single model approaches. Based on extensive surveys, the review paper predicts a continuous future expansion of such literature on different CI approaches and their optimizations with both heuristic and metaheuristic methods used for energy load forecasting and their potential utilization in real-time smart energy management grids to address future challenges in energy demand managemen

Wind farm reactive power optimization by using imperialist competitive algorithm

In this paper a new evolutionary computing method based on imperialist competitive algorithm (ICA) is used for optimization of the reactive power in a wind farm. The output power and also the reactive power of wind farms are not constant due to the oscillation in wind speed. Reactive power optimization is known as an efficient way to have an improvement in power quality and also to reduce power loss. The conventional optimization algorithms have some drawbacks, such as slow convergence and premature. ICA as one of the newest optimization algorithm could be applied in order to optimization of the reactive power and overcomes the difficulties which are coming from the traditional methods. In this paper, the reactive power consumption of a wind turbine is optimized by using (ICA) method. To illustrate the application of the method, a wind farm with some uncertainties is provided. Finally the results of the ICA method are compared with the one of conventional method. Results show that the proposed reactive power optimization method is simple and effective

PID controller adjustment for MA-LFC by using a hybrid genetic-tabu search algorithm

In this paper a hybrid Genetic-Tabu Search Algorithm (GT) is used for tuning the elements of a PID controller which is applied in a Multi Area Load Frequency Control System (MA-LFC). If a large power imbalance is suddenly happened in a multi area power electric system, generation units and also consumer sides will be affected by the distortion in the energy balance between both two sides. This inequality is firstly handled by the kinetic energy of the system turning components, but, eventually, the frequency will change. Therefore, LFC is considered as one of the most challenging issues in power system control and operation. PID type controllers are conventional solutions for MA-LFC. The three parameters of the PID controllers have been adjusted traditionally. In this paper, a PID controller is applied for the MA-LFC problem and then its parts are modified by using GT method. To validate the application of the technique, a multi area network with some uncertainties is provided. Finally the results of the GT-PID controller are compared with the ones of GA optimized controllers. The simulation results show the success and the validity of the GT-PID controller in compare with the GA - PID controller

Minimum separation between lightning protection system and non-integrated metallic structures

In the event of a direct lightning strike to a protected building which is integrated with an electrical or electronic system installed on the roof such as roof-top PV system, dangerous arcing may occur between the external lightning protection system (LPS) and the conductive components of the electrical system. To prevent such side flashes, a minimum separation distance between the metallic components and the air termination system is required. Even though, IEC62305-3 Standard provides a formula to specify the necessary separation distance, so far there is no extensive study that has been done to evaluate the suitability of the application of equation to calculate the separation distance, specifically to the safety of electrical systems integrated into the roof top of building. In this study, a new computational method has been developed for calculation of the separation distance between an LPS and metallic components on the roof. In the proposed method which is based on the theoretical background of the IEC62305-3 Standard formula, the break down behavior of the gap geometry between the LPS and the metallic components for the applied voltage across the gap is analyzed. PSCAD software was used to model the LPS and the lightning strokes

Minimum separation between lightning protection system and non-integrated metallic structures

In an event of direct lightning strike to a protected building which is integrated with an electrical or electronic system installed on the roof such as roof-top PV system,dangerous sparking may occur between external lightning protection system (LPS) and conductive components of the electrical system. To prevent such side flashes, a minimum separation distance between the metallic components and air termination system is required. Even though, IEC62305-3 Standard provides a formula to specify the necessary separation distance, so far there is no extensive study that has been done to evaluate the suitability of the application of equation to calculate the separation distance,specifically to the safety of electrical systems integrated into the roof top of building. In this study, a new computational method has been developed for calculation of the separation distance between an LPS and metallic components on the roof. In the proposed method which is based on the theoretical background of the IEC62305-3 Standard formula, the break down behavior of the gap geometry between the LPS and metallic components for the applied voltage across the gap is analyzed. PSCAD software was used to model the LPS and the lightning strokes. Separation distance has been computed considering the voltage-time area of the induced voltage across the gap as rectangle, triangle and trapezium and the results have been compared with the one considering the voltage-time area of the real voltage wave shape. It has been observed that calculated result for separation distance considering the real voltage wave shape is lower than the results for assumed voltage wave shapes. Finally, the value of separation distance which is obtained by the proposed method has been compared to the value obtained by IEC62305-3 Standard formula. The comparison indicates almost 20% difference between the values of separation distances calculated by the proposed method and IEC62305-3 standard formula, whereas the proposed method suggests lower values for separation distance. Therefore, it has been concluded that the IEC62305-3 Standard suggested formula overestimate the values of separation distance. Furthermore, effects of two parameters of resistance and inductance of earthing system that influence the value of separation distance have been investigated. It has been observed that the inductance of the earthing system plays an important role in increasing the potential across the gap and the separation distance in case of fast front lightning current, i.e. subsequent negative stroke and first negative stroke. While, influence of the earth resistance on the value of the separation distance is not remarkable for fast front lightning currents. However, for slow front lightning current such as positive stroke, the earth resistance plays an important role in determining the separation distance