Power electronics solutions for Vertical Axis urban wind turbines

Urban wind: Characterisation of useful gust and energy capture

“…Thus, dimensional reasoning, as shown in Equation (9), dictates that the minimum length scale (L u ) corresponding to the characteristic maximum gust frequency (F G ) employed in this study is approximately larger in magnitude than the diameter of a small-scale VAWT turbine (e.g. the QR5 with diameter e 3.1 m [27]). Table 1 Percentage increase across the turbulence intensity bins from the Average Power (P 10mins ) calculated from mean wind speed at 10 min (as shown in the power plots in Fig.…”

“…The effect of wind direction on the turbine (VAWT) performance within an urban environment was assumed to be negligible [27]. It is also assumed that in an idealised steady wind environment, the GEC and EEC would be 1.0 and 0% respectively [22].…”

“…Based on the assertion that the output variables of a VAWT are not affected by rapid changes in wind direction typical of an urban environment [27], it is relevant to investigate the degree to which the power output is influenced by T.I. at the sites analysed.…”

“…Tracking such gusts and avoiding deep stall involves specific design considerations. These include low turbine inertia, real-time operating conditions (as in the case of feedback controls), and a power electronics architecture which allows for active control [27].…”

A method for mapping the turbulence intensity and excess energy available to building mounted wind turbines over a UK City

“…Many of these issues can be addressed by employing effective control algorithms within the turbine system's operations . In addition, a number of studies have assessed the potential of control technologies which are able to track short‐term changes in wind speeds in order to allow turbines to operate more efficiently within urban areas (gust tracking solutions). The complex and gusty urban wind resource is affected to a large extent by the urban surface topography which is strongly influenced by the shape of buildings and structures, building arrangements and densities, and even more strongly by building height variability .…”