The increasing penetration of wind power impacts the frequency stability of power systems .The participation of wind generation in primary frequency control has become a serious concern under study .Due to the lack of contribution of these turbines in grid frequency regulation, control schemes are necessary for wind turbines and power systems to support the frequency control. Wind turbine control methods that enable frequency support and control are presented. The advantages and disadvantages of each method are discussed. This paper presents a novel frequency regulation by DFIG-based wind turbines to combined inertial control, rotor speed control and pitch angle control, under three wind speed mode (low, medium and high). Detailed models are built in MATLAB/SIMULINK and simulation results are compared. Simulation results show that this strategy improves the frequency response after a frequency drop.

Objective: The present study examined the relationship between quality of work life and performance of Railway Headquarter employees in Hormozgan province. Method: The research method is descriptive-correlation and 150 employees working in Railway Headquarter in Hormozgan were chosen through stratified random sampling. In this study, two questionnaires including a 16-item quality of work life questionnaire (Walton) and a 14-item questionnaire (Achiu performance) were used to collect the data. After collecting the data, analysis was done by using descriptive statistics and inferential statistics such as Spearman, Kendall and multiple regressions. Results: The results showed a direct and significant relationship between the quality of work life and human resource performance. Besides, there is a significant relationship between the quality of work life (fair and adequate payment, safe workplace, developing human capabilities, providing opportunities for growth and continuous security, social integration, constitutionalism in the organization, social dependence) and the employees' performance.