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Turbine systems equipped with doubly fed induction generation (DFIG) are becoming increasingly vital in wind power generation, with the reliability of the devices serving as a pillar in the industrial sector. Thermal stress and lifetime assessment are fundamental indicators in this regard. This paper primarily addresses the thermal stress and lifespan of power semiconductor devices utilized in a DFIG grid-side converter (GSC) and rotor-side converter (RSC). PLECS (Piecewise Linear Electrical Circuit Simulation) is employed to validate the electrical and thermal stress of the power devices. Additionally, Ansys Icepak, a finite element analysis (FEA) software, is utilized to confirm temperature fluctuations under various operations. The power consumption and junction temperature of the power devices in the GSC and RSC of a 2 MW DFIG are compared. It is evident that the most stressed power semiconductor is the IGBT for the GSC with a temperature swing of 3.4 °C, while the diode in the RSC is the most stressed with a temperature swing of 10.1 °C. This paper also presents a lifetime model to estimate the lifespan of the power device based on the annual wind profile. By considering the annual mission profile, we observe that the lifetime of the back-to-back power converter is limited by the diode of the RSC, whose B10 lifetime is calculated at 15 years. [ABSTRACT FROM AUTHOR]

The digitization of power grid projects is a development requirement in the era of big data, as well as an inevitable requirement for the State Grid Corporation of China to build digital power grids and improve life-cycle management. Three-dimensional design establishes three-dimensional models of ground conductors, insulators, and fittings through line electrical majors, and completes line poles and towers in a three-dimensional scene; line structure majors should establish iron tower models and basic models; survey majors should conduct topography and landforms and ground objects to complete three-dimensional scene construction. It can make the circuit design results more intuitive, reduce the drawing work of repeated components, and improve the design efficiency.

Background Local outbreak control plans (LOCPs) are statutory documents produced by local authorities (LAs) across England. LOCPs outline LAs' response to Coronavirus Disease 19 (COVID19) outbreaks and the coordination of local resources, data and communication to support outbreak response. LOCPs are therefore crucial in the nation's response to COVID-19. However, there has been no previous systematic assessment of these documents. We performed this study to systematically assess the quality of LOCPs and to offer recommendations of good practice. Methods All published LOCPs were assessed for basic characteristics. A framework based on Department of Health and Social Care guidelines was used to assess a random sample of LOCPs. Qualitative analysis was undertaken for LOCPs with highest completeness. Results Hundred and thirty-seven of 150 LAs publicly published a full LOCP; 9 were drafts. Statistical analysis demonstrated the significant difference between reporting of mainstream schools, care homes and the homeless population and other educational settings, high-risk settings and other vulnerable groups. LOCPs varied in approach when structuring outbreak response information and focused on different areas of outbreak management. Conclusions The majority of LAs are publicly accessible. There is significant variation between the reporting of high-risk settings and groups. Suggested recommendations may help to improve future LOCP updates. [ABSTRACT FROM AUTHOR]

This correspondence presents a segmentation and fitting method using a new robust estimation technique. We present a robust estimation method with high breakdown point which can tolerate more than 80% of outliers. The method randomly samples appropriate range image points in the current processing region and solves equations determined by these points for parameters of selected primitive type. From K samples, we choose one set of sample points that determines a best-fit equation for the largest homogeneous surface patch in the region. This choice is made by measuring a RESidual Consensus (RESC), using a compressed histogram method which is effective at various noise levels. After we get the best-fit surface parameters, the surface patch can be segmented from the region and the process is repeated until no pixel left. The method segments the range image into planar and quadratic surfaces. The RESC method is a substantial improvement over the least median squares method by using histogram approach to inferring residual consensus. A genetic algorithm is also incorporated to accelerate the random search.