Index-based optimal DG allocation for voltage quality improvement in an unbalanced network

Voltage quality is a one of the major concerns in distribution systems. Distributed Generations (DGs) have the potential to improve voltage quality, if optimally planned and operated. Considering the problem of DG siting and sizing, this paper aims at integrating technical factors, particularly voltage quality, in planning of DGs. Hence, a methodology is proposed which optimizes voltage quality in the presence of DGs and can be used as one of the objectives in a multi-objective problem or as an intermediate stage in usual DG planning. Modified voltage quality indices are proposed which consider factors including voltage profile, voltage variation due to DG disconnection, voltage regulation and voltage unbalance. The indices are defined in such a manner suitable for three-phase unbalanced networks. The system voltage quality is assessed by a new comprehensive voltage quality index. By applying this index, the DGs locating and penetration problem is formulated to improve system voltage quality. The method is tested on IEEE 13-bus feeder which is an inherently unbalanced network.

Load balancing algorithm based-SDN for the IoT applications

Nowadays, the emergence of IoT devices has wholly revolutionized the customer's communication habits. The information can be collected at anytime and anywhere. However, the mobility of communication devices in a dense network results in an unbalanced network load and an increase in bandwidth demands. To address these issues, this study proposed a load balancing algorithm based on SDN for enhancing the performance of mobile IoT devices communication over a Wi-Fi network. The use of the SDN makes possible the automatic configuration of the network through a centralized controller, it provides programmability, a global view of the network, it also optimizes resource allocation based on real-time network information that helps implement our algorithm. The proposed algorithm is evaluated through simulation using mininet. The results indicate that our proposed method provides an efficient network load balancing and improves the throughput of associated devices.

Using Adaptive Second Order Sliding Mode to Improve Power Control of a Counter-Rotating Wind Turbine under Grid Disturbances

This work presents a new control strategy for counter-rotating wind turbine (CRWT) driven doubly-fed induction generator (DFIG) under grid disturbances, such as unbalanced network voltage scenarios. The proposed strategy based on the power control used dynamic gains second order sliding mode control (SOSMC). The power control of a DFIG by SOSMC widely based on the super-twisting (ST) algorithm with invariable parameters and sign functions. The proposed control method consists in using dynamic-parameters ST algorithm that ensures a better result than a conventional strategy. The proposed control scheme used 2 sliding surfaces such as reactive and active powers to control them. Also, the sign functions are replaced by saturation (sat) functions in order to minimize the chattering problems. Simulation results depicted in this research article have confirmed the good usefulness and effectiveness of the proposed adaptive super-twisting algorithm of the CRWT system during grid disturbances.