Optimization Of Reactive Power Dispatch Problem With Inclusion Of Renewable Energy Resources And FACTS Devices

The power networks are the complex networks composed of power transmission,distribution and power generation subsystems.It runs with the lowest resource consumption,while ensuring the power loss,voltage deviation,voltage stability,operating cost,and ensuring reliability and safety of operation.In power system,these goals can be achieved by solving the optimal reactive power dispatch(ORPD)problem.ORPD is a nonlinear,multi-modal and non-convex optimization problem related to optimal power flow which contains discrete and continuous variables.Due to considered as a nonlinear optimization problem,it becomes very difficult to solve and have more importance in the electric power system.The fitness objectives can be achieved by adjusting control parameters such as generator voltages,transformer tap settings as well as shunt VAR compensators while meet the constraints in limits.Many elegant benefits can be obtained by using the renewable energy resources(RERs),but many technical issues related to the RERs including the stochastic characteristics of these resources due to continuous variations of solar irradiance and the wind speed led to increase the uncertainties of the system.Thus,solving the ORPD problem with inclusion of the RERs is a crucial task.In addition,ORPD problem has also had an impact on the controllability and safety of the complex networks.The power grid is composed of numerous generators,transformers,various loads and transmission lines,and supplies power to utilities.Due to the increase in load demand,burden on the power networks and transmission load become heavier,which may lead to instability issues in power grid.This power instability can be reduced by applying the advanced control technologies such as flexible AC transmission systems.Moreover,the effective reactive power dispatch on weak buses can help to reduce power loss,operating costs,improve voltage deviation as well as enhancing the voltage stability.In the past few decades,numerous optimization techniques have been studied to use conventional thermal unit for solving ORPD problem.However,they have some of difficulties to solve the intricated problem of ORPD such as trapping into the local minima,premature convergence and algorithmic complexity.To resolve these issues,the meta-heuristic optimization techniques are developed to overcome these issues.The aim of this study is to improve the overall performance of the traditional PSO,LAPO and SSA optimization algorithms to solve ORPD problem with inclusion of RERs and FACTS devices.The main research content includes:·The traditional PSO algorithm is mostly suffered with the premature convergence and trapped into the local optima.While,GSA usually requires a long computational time for some optimization problems.Afterwards,the development of fractional calculus(FC)has attracted the attentions of the researchers and was applied in plethora of fields including engineering&science.By inspiring the aforementioned ideas and decreasing the drawbacks of both algorithms by using the concept of FC.We can refer the integration of FC inside the velocity update equation of PSO,constituting fractional particle swarm optimization i.e.FPSO and is further hybridized with GSA to develop FPSOGSA.The application of FPSOGSA is used to solve ORPD problem with inclusion of RERs by scenario-based method.To modelled uncertainty in load demand,wind speed and solar irradiance are computed by normal PDF,Weibull PDF and lognormal PDF.To validate the performance of FPSOGSA is tested on IEEE 30 standard with 13 and 19 variables to reduce expected sum of power losses,voltage deviation and enhancing voltage stability.Moreover,FPSOGSA algorithm is also employed to solve simple ORPD problem tested on IEEE 30 with 13 and 19 variables as well as IEEE 57 with 25 variables to minimize power losses and voltage deviation.·Based on Levy Flight Distribution and spiral motion of particles,an efficient and reliable optimization algorithm named Modified Salp Swarm Algorithm(MSSA)is designed to enhance the searching ability of the traditional SSA.This paper presents a simplified model for SSSC which is simply implemented in NR load flow algorithm based on the power injection approach.The main advantages of this model are avoiding the modification of Jacobin matrix and reducing the complexities of incorporating SSSC in the load flow algorithm.The proposed algorithm for ORPD is tested on IEEE 30-bus and 57-bus standard to reduce power losses,voltage deviation and voltage stability.·The Flexible AC Transmission Systems(FACTS)are the static power electronic devices that are installed and used in AC transmission networks to enhance the capability of transferring the power for providing the controllability and stability.However,the optimization of site and size of these devices is a crucial task due to their high capital cost and practical capabilities.In this work,the optimal reactive power dispatch(ORPD)embedded with two effective controllers including the Static VAR Compensator(SVC)and Thyristor Control Series Capacitor(TCSC)is solved using Modified Lightning Attachment Procedure Optimizer(MLAPO).The searching capability of basic LAPO is enhanced and the stagnation of basic LAPO is avoided by application of levy flight distribution and spiral orientation motion.The proposed algorithm for ORPD is tested on IEEE 30-bus and 57-bus standard to reduce power losses,voltage deviation and voltage stability.