Application of a Digital Signal Analyzer to the easurementTofF Power System Ground Impedances
A new method is described for measuring the impedance of power system ground systems where, because of a significant reactive component or the presence of a large residual power system voltage, conventional ground resistance measuring instruments cannot be used. A white noise source together with a digital signal analyzer are used. Results of three applications are given.
Substatiion Ground Impedance: Comparative Field Measurements with High and Low Current Injection Methods
This paper describes ground electrode impedance field measurements and their analysis at Hydro- Quebec's Yamaska substation, using both high and low current injection methods. The results from both techniques are shown to compare satisfactorily. In the low current injection method, numerous measurements were performed in different directions, describing how the mutual coupling effects between the auxiliary current and potential probes can be removed with adequate analytical tools. A comparison is also made between ground impedance values at 60 and 70 Hz. Finally, an appendix includes characteristics of some of the equipment used during these measurements.
Simulation and control of hybrid renewable energy system connected to the grid
This paper presents a control and simulation of hybrid renewable energy system connected to the grid. The studied system includes a photovoltaic panel, synchronous permanent magnet generator based wind turbine, and a battery for storage energy. The PV array and wind systems are connected to the common DC bus by a boost converter. The battery is connected by a bi-directional DC/DC converter, and then integrated into the AC utility grid via a common DC/AC inverter. In order to extract the maximum energy, a simulation study has been carried out according to the meteorological conditions (wind speed and variable solar irradiance) while maintaining power quality at a satisfactory level. In order to capture the maximum power, a MPPT algorithm is applied for both wind turbine and photovoltaic panel. The modeling and simulation of the whole system has been performed under Matlab/Simulink environment. The obtained results show that the current and the voltage of grid side are sinusoidal and alternative forms, and the power injected to the grid is around the power produced by the hybrid system.