Abstract

Subject of the present work is the analysis of the connection of locally manufactured small wind turbines in small scale applications directly to batteries and also the study, simulation, construction and optimization of a diversion load charge controller.

Initially, the general characteristics of the small wind turbine are presented and especially those which will later be used in this study such as the aerodynamic characteristics of the rotor and the wind allocation, that play a significant role while calculating the annual energy yield.

The concept of microgrids is introduced and different models for the analysis of the battery connection are studied, namely the AC model and the DC model. Advantages and disadvantages concerning the two models are presented so as to justify the ΑC model as the most appropriate for our case.

Initially, an 850W (2.4m rotor diameter) small wind turbine is studied, which has been constructed in NTUA, for 48V and 24V battery connection and useful conclusions are drawn concerning power to the batteries and energy production.

Then, the connection cables between the small wind turbine and the rectifier and then to the batteries are studied while trying to maximize the annual energy production depending on the wire length and cross-sectional area.

The introduction of an inductance is investigated, in series to the small wind turbine, so as to maximize even further the annual energy yield. The 48V connection is analysed and simulated and optimal parameter values concerning the cable resistance and inductance values are suggested.

Further more, both commercial an non – commercial diversion load charge controllers are introduced and a low cost implementation in proposed which is then manufactured and tested in real conditions in the NTUA laboratory. The experimental results are then compared to those of  the simulations in order to validate them.

Finally, conclusions are deducted and further optimizations concerning various parts of the work are proposed.

Keywords: appropriate technology, low cost, small wind turbines, enhancement, microgrids, AC connection, DC connection, battery connection, inductance, charge controllers, dump load, Arduino, microcontrollers, energy production enhancement

Author: Thomas Pazios / tompaz@mail.ntua.gr

Responsible PhD: Kostas Latoufis / latoufis@power.ece.ntua.gr

Supervising Professor: Nikos Hatziargyriou / nh@power.ece.ntua.gr

PDF: Full version (Greek) and Short version (English)