sin αst

PROBLEM STATEMENT
reconfigured with different types of blades and towers. This is considered vital as the
component and material availability in developing countries varies.
The above mentioned considerations to manufacturability and flexibility are to be made
without neglecting the overall quality of the proposed wind turbine, as it will function as a
fundamental design platform from which locally matched design variants may be created.
Further elaboration of the project goals is accomplished by translating the wishes and
needs of EWB into product requirements and subsequently compiling them in a require-
ment list. This thus represents the specification against which the success of the project
can be judged. The resulting product requirements are identified either as demands or
wishes. Demands are defined as requirements that must be met under all circumstances. In
other words, if any of these requirements are not fulfilled the solution is unacceptable.
Wishes are requirements that are to be taken into consideration whenever possible, thus
describing the quality of the solution. The demands are quantified to the extent that it is
possible, while wishes primarily are relative parameters, defined in the clearest possible
terms, and used as evaluation criteria in the conceptual phase. Both the quantitative and
qualitative requirements are tabulated in table 2.1 below.
8
ID D/W Requirements
Electrical / Performance requirements
1 D 1500 W ± 1% nominal power output from the generator a
2 D 48 V DC system voltage
Manufacturing requirements
3 W Ability to manufacture the wind turbine locally using standard operations b
4 W Flexibility in choice of blade materials
5 W Low manufacturing tolerance demands
6 W Low-cost materials and parts
Normative requirements
7 D Compliance with selected parts of IEC 61400-2 c
Service requirements
8 W Ability to perform localised maintenance
9 W Low maintenance requirements and high life expectancy
Design requirements
10 W Flexibility for reconfiguration with different components
11 D Ability to install wind turbine manually, i.e. without a crane
a) Under the conditions defined in appendix B.1 and using the generator specified in chapter 7
b) Milling, turning, drilling, grinding and welding
c) See appendix K for elaboration of the relevant parts of IEC 61400-2
Table 2.1: Requirement list containing demands and wishes for the wind turbine design