Mohamed Ebeed

Enhancing security of power systems including SSSC using moth-flame optimization algorithm

This paper presents a developed optimization technique based on moth-flame algorithm to determine the optimal placement and parameter setting of Static Synchronous Series Compensator (SSSC) for enhancing power system security under single line contingencies. A contingency analysis is performed on power system to determine the most severe line outage contingencies using performance index which based on the number of thermal overloads and voltage levels violation. IEEE 30-bus test system is used to verify the effectiveness of the developed algorithm. The obtained results demonstrate that the efficiency of the developed technique moreover, installing of the SSSC in its optimal location can enhance the security of power system by reducing the overloading of transmission lines and violation of bus voltages.

Constraints Violation Handling of GUPFC in Newton-Raphson Power Flow

Abstract Generalized Unified Power Flow Controller (GUPFC) is one of the newest Flexible AC transmission system (FACTS) devices based on voltage source converters. This paper presents a developed model of GUPFC based on power injection approach. The series converters of GUPFC is represented by injected complex loads as function of the specified powers flow, while the shunt converter is represented as a synchronous condenser that provides the reactive power compensation to control the bus voltage magnitude. The main advantage of the developed model is that the original structure and symmetry of the admittance and Jacobian matrices can still be kept avoiding the changes of the original Jacobian matrix. Consequently, the complexities of the load flow are reduced. This model includes simple strategies for handling the operating constraints of GUPFC, including the injected series and shunt voltages magnitude, currents of the series and shunt converters, and the real powers exchanged in the converters. The strategies are based on decreasing one or more values of specified values or by modifying the specified values as a function of the required constraint limits. The developed model and proposed strategies for handling violation of GUPFC operating constraints are tested on IEEE test systems such as 57-bus and 118-bus systems.

Optimal Allocation of Compensators

Electric distribution networks mainly deliver the electric power from the high-voltage transmission system to the consumers. In these networks, the R/X ratio is significantly high compared to transmission systems hence power loss is high (about 10–13% of the generated power). Moreover, poor quality of power including the voltage profile and voltage stability issues may arise. The inclusion of shunt capacitors and distributed Flexible ac transmission system (D-FACTS) devices can significantly enhance the performance of distribution networks by providing the required reactive power. D-FACTS include different members such as; distributed static compensator (DSTATCOM), Distribution Static Var Compensator (D-SVC) and unified power quality conditioner (UPQC). Optimal allocation of these controllers in the distribution networks is an important task for researchers for power loss minimizing, voltage profile improvement, voltage stability enhancement, reducing the overall system costs and maximizing the system load ability and reliability. Several analytical and optimization methods have been presented to find the optimal siting and sizing of capacitors and shunt compensators in electric distribution networks. This chapter presents a survey of new optimization techniques which are used to find the optimal sizes and locations of such devices. This chapter also presents an application of new optimization technique called Grasshopper Optimization Algorithm (GOA) to determine the optimal locations and sizes of capacitor banks and DSTATCOMs. The obtained results are compared with different algorithms such as; Grey Wolf Optimizer (GWO), Sine Cosine Algorithm (SCA).

Simple modeling of HVDC systems into Newton-Raphson load flow algorithm

This paper proposes a simplified modeling for HVDC in Newton Raphson (NR) load flow algorithm based on power injection approach. In this modeling, the HVDC is represented as injected loads at their end terminals. This injected loads are updated during the iterative process as a function of the desired power flow through the HVDC connected transmission line. The main advantages of this model are avoiding the modification of Jacobin matrix and reducing the complexities of incorporating HVDC in load flow algorithm. Consequentially, load flow convergence characteristics and overall computation time are reduced. Back to Back HVDC configuration (VSC - HVDC type) is taken in consideration in the current study. Standard IEEE 14-Bus test system is used to validate the proposed model and showed its effectiveness.

Optimal reactive power dispatch considering SSSC using Grey Wolf algorithm

Static Synchronous Series Compensator (SSSC) is an efficient member of Flexible AC Transmission Systems (FACTS) devices. SSSC is connected in series with transmission lines to control the active and reactive power flow in these lines. In this paper, Grey Wolf Optimization (GWO) algorithm is developed for solving the optimal reactive power dispatch (ORPD) problem. The ORPD problem is solved with incorporating SSSC for improving the voltage profile and enhancing voltage stability of the electric system. The optimal location and parameter setting of SSSC controller is determined under a contingency state. The developed algorithm is validated using standard IEEE 30-bus test system and the obtained results are compared with the particle swarm optimization (PSO) algorithm. The simulation results demonstrate the effectiveness of the developed algorithm for solving the ORPD problem with determining the optimal location and parameter setting of SSSC. In addition superiority results are obtained with incorporating SSSC in the power systems.

Optimal setting of STATCOM based on voltage stability improvement and power loss minimization using Moth-Flame algorithm

Static Shunt Compensator (STATCOM) is a powerful member of the Flexible AC transmission system (FACTS) based on voltage source converter. STATCOM is connected in shunt with the system to provide a voltage control of a certain bus by injecting or absorbing reactive power. This paper presents an efficient optimization technique called Moth-Flame Optimization (MFO) algorithm for determining the optimal location and parameter setting of STATCOM. MFO optimization technique is inspired from transverse orientation of the moth flame. STATCOM is incorporated in power system for voltage profile improvement, voltage stability enhancement and power loss minimization. The developed algorithm is validated using the standard IEEE 30-bus test system. However, the developed optimization algorithm including simplified STATCOM model is compared with the conventional particle swarm optimization technique (PSO). The simulation results show that the efficiency and superiority of the developed algorithm for determining the optimal setting of STATCOM moreover, the effectiveness of STATCOM for enhancing the voltage stability and power loss minimizing.