Interactive Visual Analysis of Networked Systems: Workflows for Two Industrial Domains

We report on a first study of interactive visual analysis of networked systems. Working with ABB Corporate Research and Ericsson Research, we have created workflows which demonstrate the potential of visualization in the domains of industrial automation and telecommunications. By a workflow in this context, we mean a sequence of visualizations and the actions for generating them. Visualizations can be any images that represent properties of the data sets analyzed, and actions typically either change the selection of data visualized or change the visualization by choice of technique or change of parameters

Economic, environmental and mixed objective functions in non-linear process optimization using simulated annealing and tabu search

Screening of topologies developed by hierarchical heuristic procedures can be carried out by comparing their optimal performance. In this work we will be exploiting mono-objective process optimization using two algorithms, simulated annealing and tabu search, and four different objective functions: two of the net present value type, one of them including environmental costs and two of the global potential impact type. The hydrodealkylation of toluene to produce benzene was used as case study, considering five topologies with different complexities mainly obtained by including or not liquid recycling and heat integration. The performance of the algorithms together with the objective functions was observed, analyzed and discussed from various perspectives: average deviation of results for each algorithm, capacity for producing high purity product, screening of topologies, objective functions robustness in screening of topologies, trade-offs between economic and environmental type objective functions and variability of optimum solutions

A New Protection System Design of Active MV Distribution Network

The increasing implementation of renewable energy sources (RES), along with the diversity of energy source types, has additionally imposed significant operational and management problems in distribution networks. These problems are manifested in voltage regulations, system stability and coordination of protection, both in the distribution and transmission networks. For the medium voltage (MV) network, this includes new energy sources and higher amounts of fault currents, invisibility of several faults in the existing protection scheme, reduction of the range of protection devices and reduction of the possibility of detecting small fault currents with existing protection relays. Such changes significantly reduce the possibility of proper distribution system protection, both in subordinate and superior networks. The subject of this paper is the presentation of a new concept of the use of automation in the management and arrangement of power system protection dependent on the scheme and configuration of an active MV network. The goals of this analysis and research are to find and define the necessary architecture in which the scheme and appearance of the MV network should be automatically detected, and based on network topology to establish new settings of protection devices (ground fault, overcurrent and short circuit protection). The contributions of generation units of RES in the MV network must be considered. This paper specifically analyses the problems of power system management with simultaneous harmonization of protection systems both in the transmission and in the radial distribution network, offering optimization algorithms that have the ability of achieving the optimal solution. The implementation of the proposed technique was tested on a radial connection integrated with a microgrid (MG) which has the possibility of two-way power supply. The obtained results indicate that the proposed technique can solve described problems in the coordination of protection system and network management, even with the dynamic character of operation mode of the networks

Photovoltaic training facility – Upgrade and performance evaluation at Murdoch University

This project focused on upgrading the Photovoltaic Training Facility installed on the rooftop of Murdoch University’s School of Engineering and Energy building. This objective included the addition of a new battery and inverter into the system as well as a change in design configuration for optimal efficiency. The project also focused on the improvement of the monitoring, evaluation and documentation aspects of the system’s operations. In order to achieve its objectives, a literature review was first done, which included information on the previous upgrades done in phases to the PV Facility over the years. The literature review also included options for batteries and inverters. The best-suited equipment for the purposes of this project were chosen. Additionally, international standards for system monitoring, analysis and documentation were compared, namely the IEC 61724 Standard and the APVI standard. Then, parameters for monitoring could were chosen, and these included irradiance, ambient air temperature, module temperature, voltage, current and electric power. These parameters’ measurement procedures were detailed. Three test methods for evaluation of the PV facility efficiency were discussed: edge seal durability, photovoltaic system performance and energy evaluation. Lastly, the process for documentation via a monitoring log was described. The methodology for completing the upgrade to the PV Training Facility included five (5) in steps: design configuration, equipment selection, equipment approval, matching PV array and inverter, and design installation. For the battery, the Aqueous Hybrid Ion S30-0080 Battery Stack was chosen, and for the inverters, the Backup Inverter MultiGrid 3000VA and Fronius Galvo 2.0-1 were chosen. The final design configuration includes two inverters; one multimode inverter connected to the battery storage and the second one is grid-connect inverter connected to the PV array. A total of 22 modules were determined to be needed for the new system, 5 were placed in series and 4 in parallel. Further, the two extra modules need to be removed or disconnected from the array configuration. 4 AHI S30-0080 battery stacks in series were also included in the design. The design operated in 2 ways. Firstly, during normal conditions, the system maintains a charge to the battery unit. Secondly, and during disconnection from the grid, the system is capable of providing the user with an alternate supply of the specified load generated from the PV array and/ or battery. For this reason, an interconnection switching device was also included in the new design since it is more complex than the old one. The performance was analysed using the APVI standard, by measuring the following parameters: specific array yield, final PV system yield, reference solar yield, array capture losses, performance ratio, array efficiency, PV system efficiency. The inverter efficiency was determined to be approximately 94%. During performance monitoring, it was decided that the PV arrays needed to be cleaned to remove dirt build up on the surfaces. This, as well as shading by trees, created disruptions in the performance analysis. The project concludes by identifying that a majority of the components in the PV training facility work effectively but there is one inverter that is not operational and that manifests problems in relation to compatibility with the available software. The performance analysis conducted also illustrates that there are arrays that are located in a manner that is not suitable to support data collection for performance analysis – for instance due to shading and irradiance

Learning by Viewing: Generating Test Inputs for Games by Integrating Human Gameplay Traces in Neuroevolution

Although automated test generation is common in many programming domains, games still challenge test generators due to their heavy randomisation and hard-to-reach program states. Neuroevolution combined with search-based software testing principles has been shown to be a promising approach for testing games, but the co-evolutionary search for optimal network topologies and weights involves unreasonably long search durations. In this paper, we aim to improve the evolutionary search for game input generators by integrating knowledge about human gameplay behaviour. To this end, we propose a novel way of systematically recording human gameplay traces, and integrating these traces into the evolutionary search for networks using traditional gradient descent as a mutation operator. Experiments conducted on eight diverse Scratch games demonstrate that the proposed approach reduces the required search time from five hours down to only 52 minutes

A survey on enhancing grid flexibility through bidirectional interactive electric vehicle operations

Smart grids (SG) constitute a revolutionary concept within the energy sector, enabling the establishment of a bidirectional communication infrastructure. This infrastructure significantly improves control, efficiency, and overall service quality in power systems. The study provides an in-depth survey on the classification of EVs, including both plug-in and non-plug-in EVs, and the integration process of V2G, including bidirectional power flow analysis. Moreover, various control strategies for EV integration are explored, ranging from centralized and decentralized to hierarchical control structures. Further, the research thoroughly examines the potential benefits of EV integration and addresses associated challenges, such as battery degradation, infrastructure requirements, cybersecurity and communication issues, grid congestion, and consumer behavior. The study goes beyond theoretical exploration and offers a comprehensive simulation analysis. This analysis leverages the storage capabilities of EVs to provide grid support services. A real-time dynamic dispatch strategy is formulated to integrate EVs into the automatic generation control of multi-energy systems. The findings demonstrate that EVs can effectively mitigate forecasting errors in a power network heavily reliant on wind energy sources. Consequently, the storage capabilities of EVs contribute to enhancing grid flexibility in managing the intermittency of renewable energy resources

An automatic selection of optimal recurrent neural network architecture for processes dynamics modelling purposes

A problem related to the development of algorithms designed to find the structure of artificial neural network used for behavioural (black-box) modelling of selected dynamic processes has been addressed in this paper. The research has included four original proposals of algorithms dedicated to neural network architecture search. Algorithms have been based on well-known optimisation techniques such as evolutionary algorithms and gradient descent methods. In the presented research an artificial neural network of recurrent type has been used, whose architecture has been selected in an optimised way based on the above-mentioned algorithms. The optimality has been understood as achieving a trade-off between the size of the neural network and its accuracy in capturing the response of the mathematical model under which it has been learnt. During the optimisation, original specialised evolutionary operators have been proposed. The research involved an extended validation study based on data generated from a mathematical model of the fast processes occurring in a pressurised water nuclear reactor.Comment: 32 pages, 17 figures, code availabl