This paper presents a study of comparison of PWM power rectifier between 6 Pules and 12 Pules converter topology by small hydro turbine Generator (20kW) is power supply and Compare harmonics Current feed in the systems. Both converter connected Permanent Magnet Synchronous Generator (PMSG) and Voltage Regulator Control at 700 V. The control system by Decoupling Control and Conventional PI Control for control parameter PI value by Nicole-Ziegler method. Analysis for Performance of the system presented a mathematical model with Matlab/Simulink program. The result of simulation have value less than 5 percent of ripple voltage and Voltage Control continuously. Converter 12 pulse have harmonics Current value feed in the systems less than converter 6 pulse. This Case study can apply using PWM power rectifier control in future work

This paper presents a study of low-frequency oscillations in compensated electric power systems with Flexible AC Transmission System of the power system frequency using PSAT Tool box To assist in the analysis of the stability of the system When the power transients in power systems is simulated By using standard IEEE 14 bus system as a case study. The Equipment that used to control the swing frequency of the is a flexible electrical power control devices or FACTS are two kinds of serial and parallel. The analysis showed that two models are compared with the time (Time Domain) and see the effect of the Eigen (Eigen Value) of the simulation results show work to see that controls are electrical flexible compensation. of low frequency oscillations in power systems in acceptable coordinates