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This paper proposes a new Smart-Load concept using AC drives. The concept is based on a secondary control layer coordinated with the network and the load to provide active power support. The general Smart-Load concept is developed and synthesized for its practical implementation in network power-frequency support applications. A multi power-frequency droop line is proposed. The final idea is applied to a fan load powered by an AC drive based on an induction motor and a two level voltage source converter. Experimental results show that a full power-frequency response can be achieved by the Smart-Load within 2s of the network frequency deviation.

This paper gives a comparative analysis of the performance of a wind turbine direct drive train system with PMSG and fully rated converters when two different wind turbine models are used for its assessment. The impact of the advanced Aero-Hydro-Servo-Elastic model, and the most common analytical function wind turbine model, on the generator-converter dynamics are assessed. Results corresponding to the system response to steps up/down in wind speed and turbulent wind speed conditions are presented and discussed in the paper. It is found that below rated speed there is no significant difference between results obtained from both models. Above rated wind speed there exist some differences among results.

At present, over 1500 offshore wind turbines (OWTs) are operating in the UK with a capacity of 5.4GW. Until now, the research has mainly focused on how to minimise the CAPEX, but Operation and Maintenance (O&M) can represent up to 39% of the lifetime costs of an offshore wind farm, mainly due to the assets’ high cost and the harsh environment in which they operate. Focusing on O&M, the HOME Offshore research project (www.homeoffshore.org) aims to derive an advanced interpretation of the fault mechanisms through holistic multiphysics modelling of the wind farm. With the present work, an advanced model of dynamics for a single wind turbine is developed, able to identify the couplings between aero-hydro-servo-elastic (AHSE) dynamics and drive train dynamics. The wind turbine mechanical components, modelled using an AHSE dynamic model, are coupled with a detailed representation of a variable-speed direct-drive 5MW permanent magnet synchronous generator (PMSG) and its fully rated voltage source converters (VSCs). Using the developed model for the wind turbine, several case studies are carried out for above and below rated operating conditions. Firstly, the response time histories of wind turbine degrees of freedom (DOFs) are modelled using a full-order coupled analysis. Subsequently, regression analysis is applied in order to correlate DOFs and generated rotor torque (target degree of freedom for the failure mode in analysis), quantifying the level of inherent coupling effects. Finally, the reduced-order multiphysics models for a single offshore wind turbine are derived based on the strength of the correlation coefficients. The accuracy of the proposed reduced-order models is discussed, comparing it against the full-order coupled model in terms of statistical data and spectrum. In terms of statistical results, all the reduced-order models have a good agreement with the full-order results. In terms of spectrum, all the reduced-order models have a good agreement with the full-order results if the frequencies of interest are below 0.75Hz.

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In this paper, a method for lifetime estimation of insulated-gate bipolar transistor (IGBT) power electronics (PE) modules in offshore wind turbine (WT) applications is presented. The PE module is studied using a time-series WT simulation model. The WT model employs a detailed representation of the system, including a two-mass representation of the mechanical side, d-q representation of the permanent magnet synchronous generator (PMSG), and an appropriately controlled back-to-back voltagesource converter (BVSC). Additionally, in order to monitor the temperature cycling, a thermal model which considers the losses in an IGBT module has been added. The temperature cycles are counted using a rain flow algorithm and the resulting effect on lifetime is calculated using Miner's rule for damage accumulation. The system is parametrised according to current state-of-theart offshore wind turbine technology.

A telecommunication system is vital for the operation and control of large electric power systems such as present and future multi-terminal HVDC networks. The latency in data transmission, and the variation in latency, known as jitter, are one of the most important features, in addition to reliability and security, to be considered in the modelling of telecommunication networks when assessing the overall performance of electric power systems. Further, in switched packet telecommunication systems, such as the internet, data packets arriving out of order might occur. Based on the behaviour of switched telecommunication networks and considering the latency as the main component to be represented, in this paper, a telecommunication model is developed and a user defined component is built in PSCAD/ EMTDC using the FORTRAN 90 language. Such a model is suitable to represent telecommunication networks with variable and constant latency as well as switched packet telecommunication systems, i.e. the internet and telephone networks. Results obtained from the application of the telecommunication model to the control a multi-terminal VSC HVDC network, interfacing offshore wind power generation, are then presented and discussed in the paper.