Self-adaptive Global Harmony Search Research Articles

Self-Adaptive Global-Best Harmony Search Algorithm-Based Airflow Control of a Wells-Turbine-Based Oscillating-Water Column

The Harmony Search algorithm has attracted a lot of interest in the past years because of its simplicity and efficiency. This led many scientists to develop various variants for many applications. In this paper, four variants of the Harmony search algorithm were implemented and tested to optimize the control design of the Proportional-Integral-derivative (PID) controller in a proposed airflow control scheme. The airflow control strategy has been proposed to deal with the undesired stalling phenomenon of the Wells turbine in an Oscillating Water Column (OWC). To showcase the effectiveness of the Self-Adaptive Global Harmony Search (SGHS) algorithm over traditional tuning methods, a comparative study has been carried out between the optimized PID, the traditionally tuned PID and the uncontrolled OWC system. The results of optimization showed that the Self-Adaptive Global Harmony Search (SGHS) algorithm adapted the best to the problem of the airflow control within the wave energy converter. Moreover, the OWC performance is superior when using the SGHS-tuned PID.

Developing heuristic multi-criteria auto calibration method for continuous HEC-HMS in snow-affected catchment

ABSTRACTTwo search methods are currently available for calibrating the HEC-HMS program: the Univariate Gradient (UG) and the Nelder Mead (NM) methods; both having poor performance in continuous models with snowmelt module. In this paper, a novel approach using Melody Search algorithm (MeS) is presented for auto-calibration of HEC-HMS and compared to Self-adaptive Global Harmony Search (SGHS) and Genetic Algorithms (GA). The results show that the suggested approach is able to overcome the poor performance of aforementioned methods yielding more enhanced solutions. While NM and UG reach a Nash Sutcliffe Index (NSE) of −0.33 and 0.105, GA, SGHS and MeS have been able to reach to 0.526, 0.635, and 0.674 respectively. In addition, the improving power of algorithms was tested by starting from the final solution found by the other methods. It was noticed that in all cases MeS and to some degree SGHS are able to substantially improve the solutions found by either UG or NM. Interestingly, while SGHS was able to slightly improve the solution of MeS algorithm, MeS made a substantial improvement on the solution reached by the SGHS. Finally, the novel MeS based multi-objective algorithm proposed here, i.e. NSMeS, and Non-dominated Sorting Genetic Algorithm-II (NSGA-II) are compared with different combinations of objective functions where NSMeS demonstrated better performance.

Application of Static Var Compensator (SVC) With PI Controller for Grid Integration of Wind Farm Using Harmony Search

Abstract Large-scale integration of wind turbine generators (WTGs) may have significant impacts on power system operation with respect to system frequency and bus voltages. This paper studies the effect of Static Var Compensator (SVC) connected to wind energy conversion system (WECS) on voltage profile and the power generated from the induction generator (IG) in wind farm. Also paper presents, a dynamic reactive power compensation using Static Var Compensator (SVC) at the a point of interconnection of wind farm while static compensation (Fixed Capacitor Bank) is unable to prevent voltage collapse. Moreover, this paper shows that using advanced optimization techniques based on artificial intelligence (AI) such as Harmony Search Algorithm (HS) and Self-Adaptive Global Harmony Search Algorithm (SGHS) instead of a Conventional Control Method to tune the parameters of PI controller for SVC and pitch angle. Also paper illustrates that the performance of the system with controllers based on AI is improved under different operating conditions. MATLAB/Simulink based simulation is utilized to demonstrate the application of SVC in wind farm integration. It is also carried out to investigate the enhancement in performance of the WECS achieved with a PI Controller tuned by Harmony Search Algorithm as compared to a Conventional Control Method.