Dynamic analysis of a two-input Zeta converter topology for modular hybrid PV-wind microgrid system

© 2015 IEEE. This paper presents the dynamic modeling of a two-input Zeta converter topology using State-space averaging (SSA) technique. The modeling leads to a small-signal linear dynamic model of the multiple-input converter (MIC), from which the transfer functions used for feedback control design can be determined. To verify the accuracy of the obtained model, a two-input Zeta converter with inputs from PV array and wind turbine generation system (WTGS) is designed which can produce an output voltage of 350 Vdc and an output power of 1kW. A controller for this is designed based from the transfer functions derived from the dynamic analysis conducted. Simulation tests of the design are performed using blocks and component of Matlab/Simulink from its SimPower Systems Toolbox. Results are presented to verify the accuracy of the obtained model

Spectrum survey of VHF and UHF bands in the Philippines

In this paper, the spectrum occupancy of the VHF and UHF bands are investigated. The primary objective is to identify the bands that have low utilization and could be accessed for future developments in TV broadcasting, especially in the analog to digital transition as well as other digital technological developments. Results could provide an avenue for emerging technologies such as cognitive radio. The study consists of data collection and analyses in the VHF and UHF TV bands. Average occupancy calculations based on measurements and results taken over a two-day period show an overall average occupancy of about 16% of the total spectrum surveyed. Specifically, average occupancies for the low band VHF, high band VHF and UHF band are about 57%, 60% and 7% of the respective bands. Since the study on white space is at its early stages, this paper serves as a preliminary study, thus further studies are needed to fully optimize the white spaces of the spectrum for future applications in the advancement of the technology. © 2012 IEEE