Active power control (APC) refers to a mode of operation where the wind turbine tracks a desired power reference command. It enables wind farms to perform frequency regulation and to provide ancillary services in the energy markets. This paper presents a linear parameter varying (LPV) approach for APC. The multiple-input, multiple-output controller builds upon a previous gain-scheduled design. ...

Reducing the settlements of soft foundation effectively is a critical problem of high-speed railway construction in China. The new CFG pile-slab structure composite foundation is a ground treatment technique which is applied on CFG pile foundation and pile-slab structure composite foundation. Based on the experience of constructing Beijing-Shanghai high-speed railway in China, the settlement-co...

Results from bi-directional tests are not the same as those obtained from top loading tests and although bi-directional test data often contain more geotechnical information, it is the characteristic behaviour of the head of the pile which is of interest. In order to provide an equivalent top loading characteristic, methods have been developed to enable the addition of the individual components...

This paper proposes an algorithm for estimating on-line the rollover risk of huge machines moving on natural ground. The approach is based on the reconstruction of lateral load transfer thanks to an observer, able to take into account terrain specificities (grip conditions and geometry). Capabilities are tested through experiments using a grape harvester.

Offshore wind energy capitalizes on the higher and less turbulent wind speeds at sea. To enable deployment of wind turbines in deep-water locations, structures are being explored, where wind turbines are placed on a floating platform. This combined structure presents a new control problem, due to the partly unconstrained movement of the platform and ocean wave excitation. If this additional com...

Effect of static load on activity of motor centers controlling motor activity (walking, flight) was studied in the American cockroach Periplaneta americana L. It has been established that under effect of load on the animal body the relative excitability of these centers increases. A suggestion is put forward about the presence of common neuronal elements in the generator networks providing moto...

Melt-freeze crusts often occur as a result of wet snow, rain or strong insolation. Past observations have revealed the formation of weak layers at their boundaries, even when the depth-averaged temperature gradient favours rounding. Research has, however, predominantly targeted temperature regimes dominated by kinetic growth. During the winter of 2007-2008 University of Calgary researchers unde...

It has been argued that the AASHTO LRFD design code for maximum live loads on highway bridges is overly conservative. In an attempt to determine the level of conservativeness, if any, the writers developed a methodology incorporating real-time visual data collection from traffic cameras coupled with structural strain response of girder bridges. Average daily truck traffic along with frequency o...

The objective of this paper is to construct a low-order model of a wind farm that can be used for control design and analysis. There is a potential to use wind farm control to increase power and reduce overall structural loads by properly coordinating the turbines in a wind farm. To perform control design and analysis, a model of the wind farm needs to be constructed that has low computational ...

In the case of Figure 1, the bridge is said to be fully active. In some cases, only half of the bridge may be active (half active). For some sensors, only a single element of the bridge may change in response to the stimulus. This application note will focus specifically on load cells, a type of strain gauge that is typically used for measuring weight. Even more specifically, the focus will be ...