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Title: Optimizing small wind turbine performance in battery charging applications

Conference ·
OSTI ID:87044
; ;  [1];  [2]
  1. National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.
  2. State Engineering Univ. of Armenia, Yerevan (Armenia)

Many small wind turbine generators (10 kW or less) consist of a variable speed rotor driving a permanent magnet synchronous generator (alternator). One application of such wind turbines is battery charging, in which the generator is connected through a rectifier to a battery bank. The wind turbine electrical interface is essentially the same whether the turbine is part of a remote power supply for telecommunications, a standalone residential power system, or a hybrid village power system, in short, any system in which the wind generator output is rectified and fed into a DC bus. Field experience with such applications has shown that both the peak power output and the total energy capture of the wind turbine often fall short of expectations based on rotor size and generator rating. In this paper, the authors present a simple analytical model of the typical wind generator battery charging system that allows one to calculate actual power curves if the generator and rotor properties are known. The model clearly illustrates how the load characteristics affect the generator output. In the second part of this paper, the authors present four approaches to maximizing energy capture from wind turbines in battery charging applications. The first of these is to determine the optimal battery bank voltage for a given WTG. The second consists of adding capacitors in series with the generator. The third approach is to place an optimizing DC/DC voltage converter between the rectifier and the battery bank. The fourth is a combination of the series capacitors and the optimizing voltage controller. They also discuss both the limitations and the potential performance gain associated with each of the four configurations.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC36-83CH10093
OSTI ID:
87044
Report Number(s):
NREL/TP-441-7808; CONF-950309-8; ON: DE95009211; TRN: AHC29521%%100
Resource Relation:
Conference: 25. annual conference and exhibition on wind power, Washington, DC (United States), 26-30 Mar 1995; Other Information: PBD: May 1995
Country of Publication:
United States
Language:
English