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This paper deals with a multiterminal voltage source converter (VSC)-based high voltage dc transmission system (M-HVDC) connecting offshore wind farms to onshore ac grids. Three M-HVDC configurations studied, each with different control strategies. The voltage-current characteristics of VSCs are presented and VSC converter operation with different output powers from offshore wind farms is assessed. A generalized droop control strategy is mainly used to realize autonomous coordination among converters without the need of communication. Operation of the three configurations with respect to their control system is analyzed through PSCAD/EMTDC simulations and experimentation. Results show control performance during wind power change, eventual permanent VSC disconnection, and change in power demand from the ac grid side converter.Index Terms-Configuration, VSC based multi-terminal HVDC, offshore wind farms, improved proportional droop control, generalized droop control strategy.

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Transient stability is important in power systems. Disturbances like faults need to be segregated to restore transient stability. A comprehensive review of fault diagnosing methods in the power transmission system is presented in this paper. Typically, voltage and current samples are deployed for analysis. Three tasks/topics; fault detection, classification, and location are presented separately to convey a more logical and comprehensive understanding of the concepts. Feature extractions, transformations with dimensionality reduction methods are discussed. Fault classification and location techniques largely use artificial intelligence (AI) and signal processing methods. After the discussion of overall methods and concepts, advancements and future aspects are discussed. Generalized strengths and weaknesses of different AI and machine learning-based algorithms are assessed. A comparison of different fault detection, classification, and location methods is also presented considering features, inputs, complexity, system used and results. This paper may serve as a guideline for the researchers to understand different methods and techniques in this field. transmission system topologies can be minimized by using the interspersed sensors for the collection of voltage and current signals. The second limitation is the lack of computational capability and communication. Synchronized global positioning system (GPS) sampling and high-speed broadband communications for IEDs in power grids are proposed in [8]. These technical advancements assure the quick response to faulty scenarios and the effective functioning of online monitoring mechanisms based on sensor networks. The availability of high-performance computing solutions gives provision to the implementation of higher computation complexity methods [7].Short circuit faults are more likely to appear in power systems (PS) than the series faults, break in the path of current. Shunt faults result in catastrophes and leave hazardous effects on PS. Short circuit faults can be divided into symmetrical and asymmetrical faults and further classification is presented in Figure 1 for the three-phase system [11].

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Renewable energy sources (RESs) are the replacement of fast depleting, environment polluting, costly, and unsustainable fossil fuels. RESs themselves have various issues such as variable supply towards the load during different periods, and mostly they are available at distant locations from load centers. This paper inspects forecasting techniques, employed to predict the RESs availability during different periods and considers the dispatch mechanisms for the supply, extracted from these resources. Firstly, we analyze the application of stochastic distributions especially the Weibull distribution (WD), for forecasting both wind and PV power potential, with and without incorporating neural networks (NN). Secondly, a review of the optimal economic dispatch (OED) of RES using particle swarm optimization (PSO) is presented. The reviewed techniques will be of great significance for system operators that require to gauge and pre-plan flexibility competence for their power systems to ensure practical and economical operation under high penetration of RESs.

In this article, a compact and planar wearable ultra‐wideband (UWB) antenna is designed and characterised for wireless body area network (WBAN) applications. The antenna is designed and fabricated on two different substrates: a thin and flexible high‐end RT/Duroid 5880 substrate (h = 0.381 mm) and a low‐end FR4 substrate (h = 1.6 mm) having fabricated antenna dimensions of 86 mm × 72 mm and 75 mm × 61 mm, respectively. The dimensions of the proposed design for both the substrates are calculated using the well‐known transmission‐line model. The antennas are simulated using ADS momentum and CST microwave studio for evaluation of work using two different modelling techniques. The antenna structure consists of a rectangular radiating patch with a rectangular slot and a reduced ground plane to improve the impedance matching characteristics. An offset‐feed method is employed to enhance the overall patch bandwidth. The measured −10 dB impedance bandwidth and gain with the RT/Duroid 5880 and FR4 substrates are 7.1 GHz (3.5–10.6 GHz)/4.89 dBi and 7.2 GHz (3.8–11 GHz)/2.75 dBi, respectively. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1710–1715, 2016

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