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Future power systems, in which generation will come almost entirely from variable Renewable Energy Sources (vRES), will be characterized by weather-driven supply and flexible demand. In a simulation of the future Dutch power system, we analyze whether there are sufficient incentives for market-driven investors to provide a sufficient level of security of supply, considering the profit-seeking and myopic behavior of investors. We co-simulate two agent-based models (ABM), one for generation expansion and one for the operational time scale. The results suggest that in a system with a high share of vRES and flexibility, prices will be set predominantly by the demand’s willingness to pay, particularly by the opportunity cost of flexible hydrogen electrolyzers. The demand for electric heating could double the price of electricity in winter, compared to summer, and in years with low vRES could cause shortages. Simulations with stochastic weather profiles increase the year-to-year variability of cost recovery by more than threefold and the year-to-year price variability by more than tenfold compared to a scenario with no weather uncertainty. Dispatchable technologies have the most volatile annual returns due to high scarcity rents during years of low vRES production and diminished returns during years with high vRES production. We conclude that in a highly renewable EOM, investors would not have sufficient incentives to ensure the reliability of the system. If they invested in such a way to ensure that demand could be met in a year with the lowest vRES yield, they would not recover their fixed costs in the majority of years., Energie and Industrie, Intelligent Electrical Power Grids

Anticipating failures is vital for maintaining a reliable power supply. Advanced measurement devices in the grid generate vast data that contains valuable information on grid operations. Initial signatures of an incipient failure are often reflected in this data in the form of electrical waveform distortions. Conventional protection schemes are not equipped to analyze these distortions and anticipate failures. There is a considerable research gap for a simple yet robust and universal failure anticipation and diagnosis scheme. This paper proposes a universal Failure Anticipation and Diagnosis Scheme (FADS) to detect incipient failures in AC distribution grids. The method comprises three short stages, helping the operator make an informed decision. In the first stage, the FADS scheme leverages the fundamental properties of electrical sinusoid waveforms to detect distortions. In the second stage, the distortion data is processed through pre-determined thresholds set in accordance with the system's regular operation. In the third stage, depending on the system, the FADS uses the extent of the violations of these thresholds and ranks the severity of the danger posed to grid operations. The classification helps determine if the waveform distortions are the signature of an incipient failure. The proposed FADS method's reliability, robustness and effectiveness are evaluated in incipient failure conditions of field events modelled in real-time simulations on standardized IEEE distribution feeders. The FADS is a high-speed distortion detector, is quite sensitive, and the method has high selectivity because of its nature., Intelligent Electrical Power Grids, Electrical Sustainable Energy

This paper introduces a flexible and extendable easy-to-use energy system integration development kit: the Illuminator. The Illuminator illustrates challenges arising from the energy transition. Hence, it is suitable in education and for demonstration. It also acts as a sandbox for testing new research concepts, and particularly, distributed energy coordination algorithms in real and non-real time. The Illuminator technology is primarely a modular software platform developed to run on a Raspberry Pi (RasPi) cluster. It is open-source, available at GitHub and developed in Python. The Illuminator comprises models of common energy technologies, such as photovoltaic (PV) panels, wind turbines, batteries, and hydrogen systems. The uniqueness of the Illuminator is in its modularity and flexibility to reconfigure scenarios and cases on the fly, even by non-experts in a plug-and-play fashion. This paper introduces the Illuminator and shows its performance in a simple case study., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids, ESP LAB, Electrical Sustainable Energy

As the penetration of Converter-Interfaced Dis-tributed Renewable Energy Sources (CI-DRES) increases, several problems are revealed in electric power systems, e.g., power quality issues, reverse power flows and frequency instability. A solution to tackle these issues is the mitigation of high CI-DRES active power ramp-rates (RRs) by utilizing energy storage systems (ESS). In many grid-codes at transmission system (TS) level, it is specified that the CI-DRES limit their RRs, while also the utilization of a central ESS has been proposed to limit the RRs. Nevertheless, this approach involves only large energy market players. Although various RRL methods have been proposed for CI-DRES, a remaining gap is the evaluation of the RR of a Distribution Network (DN) containing CI-DRES and loads together with the influence of distributed ESS in the DN. Towards this direction, in this paper, this evaluation is performed in order to study the RRL capability of a low-voltage (LV) DN considering both central and distributed ESS. The analysis is conducted in the LV CIGRE DN via quasi-steady-state and RMS simulations in PowerFactory considering several techno-economic parameters, e.g., ESS size, type, per unit cost. This evaluation will help towards the integration of the RRL control in the grid codes in DNs so that it can be considered as a new ancillary service to be remunerated in respective markets where also small CI-DRES owners will be able to participate., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

Electrification of processes and utilities is considered a promising option towards the reduction of greenhouse gas emissions from the chemical industry. Therefore, electricity demand is expected to increase steeply. Since the sources of future low-carbon electricity are variable in nature, there is a need for strategies to match availability and demand. Literature identified the flexibility of chemical processes as one promising strategy to address variability. This study aims to provide insights into how stakeholders from the power sector and the chemical industry consider flexibility in chemical processes and to identify key benefits and bottlenecks. For this article, we combined a review of peer-reviewed and grey literature with stakeholder interviews to map and describe the state of the art of flexible chemicals production, and to identify requirements for further research. The main drivers to investigate the flexibility potential are first, the contribution to energy system reliability, and second, potential cost savings for the industry. Main limitations are considered to be first, the uncertain economic performance of flexible processes due to investment costs, reduced production and uncertain revenues from flexible operation, and second, the complexity of the implementation of flexibility., Energie and Industrie, Intelligent Electrical Power Grids

This paper deals with a systematic assessment of the power system frequency dynamics under high penetration of converter-interfaced renewable energy sources (CI-RESs). Specifically, the concept of the virtual synchronous generator (VSG) is implemented in the CI-RESs located at the transmission system (TS) side and/or the distribution network (DN) side. Dynamic RMS simulations are performed on a testbed consisting of the IEEE 9-bus TS grid and the CIGRE medium-voltage DN grid under different CI-RES penetration levels and VSG control parameters to assess the VSG impact on the power system frequency dynamics. It is shown that the decommissioning of conventional power plants coupled via synchronous generators can be safely performed in case the VSG concept is adopted correctly., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

As the penetration of distributed energy resources (DERs) increases significantly in the distribution networks, their integration reshapes distribution system power flows and leads to serious voltage quality problems in distribution networks. In this paper, a novel distributed cooperation voltage regulation method is proposed for future distribution networks. The proposed method can minimize the number of agents involved in the voltage regulation and it minimizes the change of required power for voltage regulation, which together minimizes the need for re-dispatching, i.e. the impact of voltage regulation on exchange of energy. Moreover, the proposed method performs online optimization, i.e the value of the decision variable is physically implemented as a controller set-point at each iteration which reduces the response time. The presented algorithm is benchmarked against ADMM and centralized optimization. The results show the voltage regulation effectiveness. Compared to the centralized method, the proposed method performs better in the case of a single agent failure, and compared to the ADMM method, the proposed method greatly reduces the action time and does not require retuning if network topology or agent participation changes., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

A numerical model of a power system can be used to get accurate insights into the impact of policies and investment decisions regarding the transformation of the energy system, while also helping in identifying bottlenecks in implementing decisions. Spatial aggregation, especially for generation and load, must be carefully approached to obtain such a valid model of a power system. The two main contributions of this paper are introducing a valid model of the Dutch high-voltage power system based on open data and open-source software, and proposing a method for spatially aggregating generation and load capacities to high-voltage nodes of the power system. The representative model will enable interdisciplinary research on policy-making and investment decisions specific to the Netherlands., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

Power-to-X (PtX) technologies are accelerating the energy transition. Increasingly, these technologies are also being leveraged as flexible energy resources to support the electrical grid. PtX models are often represented using a constant efficiency term as a linear relation between the power input and energy output. However, the operational performance of any PtX device such as an electrolyser or an electric heat pump can depend on factors such as operational temperature. In this paper, we have developed and analyzed two levels of model fidelity of the most widely assessed PtX technologies: electrolyser and heat pump systems. We assess the impact of detailed models on operation of PtX within simulation-based energy system analysis. Our results show that for electrolyser systems, the efficiency errors can be almost 0.6%. With heat pump systems, the difference in COP can be as high as 1.4., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

The traditional methodology for conducting technical assessments of multi-energy systems involved using domain-specific modeling tools to focus on the energy sector of interest, while making simplifying assumptions about any coupled energy sector. This was acceptable since the interactions between energy domains were minimal. However, with the expectation of an increased adoption of energy conversion technologies (such as power to X (P2X) systems: power to heat, power to gas, etc.) in the future, and consequently higher interaction between various energy sectors and stronger dependence on one another, there is a need to update the current method for conducting technical assessments. This means taking into account not only the energy sector of interest, but also any dependent energy sectors, and the associated energy transformers (P2X). In this paper, we propose a co-simulation based approach to conduct simulation-based technical assessments of multi-energy systems, which allows us to couple domain specific modeling tools. We re-introduce the tool ENERGYSIM to conduct the multi-energy system co-simulations. We motivate the importance of the proposed tool and compare it with other available tools. We highlight its main functionalities, and using a study case, we show how a multi-stakeholder, multi-energy system co-simulation can be set up and assessed., Intelligent Electrical Power Grids

Flexibility will be required as more renewable generation is integrated in the power system. Therefore, entities such as Flexibility Service Providers (FSPs) have emerged who can control a diverse set of resources in their portfolio to provide requested flexibility. An accurate and reliable assessment of the amount of dispatchable flexibility in FSP's portfolio considering demand response activation, ramp rate, and post-activation rebound effects, etc. is important. In case FSP portfolio cannot fulfill the flexibility request, it must be known beforehand to avoid imbalance penalties. In this paper, we propose three flexibility quantification metrics: Expected Unserved Flexible Energy (EUFE), Expected Duration of Insufficient Flexibility (EDIF), and Expected Flexibility Index (EFI). These metrics are calculated using scenario-based simulations. The three metrics provide the FSP with quantifiable as well as graphical information on the magnitude and the duration of insufficient flexibility well ahead of gate closure time. This helps the FSP to design appropriate demand response programs (DRPs) and formulate their operational policy. These metrics account for uncertainty in forecasts of flexibility requests by evaluating multiple scenarios by conducting an operational simulation. With a representative case study, it is shown how an FSP can use the metrics to design DRPs, and when needed, schedule intraday market participation., Intelligent Electrical Power Grids

This chapter provides a brief overview of modelling and simulation approaches for smart grid systems. A special focus is put onto the coupling of simulation environments; i.e., the co-simulation of power systems and its components. Furthermore, selected implementations of standardized interfaces for domain simulators covering the domains of power systems and ICT are presented., Intelligent Electrical Power Grids

The rapid growth of rooftop solar, and on the rise technologies such as electric vehicles and heat pumps, is leading to congestion problems in low voltage distribution networks. If not dealt with, the congestion will prevent the installation of further units limiting the pace of the energy transition. Energy Storage Systems (ESS) are often seen as the technology with a high potential for congestion reduction. In this paper, we propose to use Relocatable Energy Storage System (RESS) fleet, to physically move the ESS throughout the distribution grid in an effort to alleviate congestion. The proposed method consists of two parts. First, a Mixed Integer Linear Program (MILP) is created to minimise the amount of RESS used and penalise displacement. Second, an algorithm with a Minimum Cost Maximum Matching objective is used to determine the dispatch of each individual RESS. The results on a CIGRE test system show the benefits of this method compared to stationary placed ESS in the grid., "Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.", Intelligent Electrical Power Grids

Renewable Energy Sources (RES), and especially wind turbines (WT) as the most mature technology, will provide a large share of energy generation in a future sustainable power system. This development introduces several challenges that need to be addressed in order to ensure a safe transition away from the fossil-fuel based generation. One of the segments where RES will have a major impact is ancillary services, such as frequency support. Until now, RES (Wind & Solar) did not participate at frequency regulation of the system, which will change as their numbers in the grid increase. The contribution of this paper is the investigation of the system impact of wind generation, when wind turbines are equipped with a control system that provides frequency related ancillary services. More specifically, we analyze primary frequency response and inertial response in the case when Doubly Fed Induction Generator (DFIG) wind turbines are equipped with Energy Storage Systems (ESS). The results are presented for different levels of RES penetration and different levels of ESS deployment, "Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.", Intelligent Electrical Power Grids

Reliable power supply to the consumers is the key goal for power utilities. The two key reliability indices for power utilities are SAIDI and SAIFI. These indices indicate the average duration and frequency of supply interruptions for the consumer. A low value on these indices reflects a reliable and mostly uninterrupted power supply. Reliability of the power supply is most threatened by events such as incipient failures that often go undetected by conventional protection schemes and can significantly increase average outage duration. However, such events initially manifest in terms of distortions in current and voltage waveforms. In this paper, waveform distortions are leveraged to detect and locate such events before they cascade to cause further damage. Early detection and localization will help in planning a swift response and mitigation of risk. Such a timely action will reduce the outage duration and interruption frequency, eventually leading to improvement in grid reliability indices. The paper further investigates these concepts by evaluating case studies on an IEEE-34 Node Distribution feeder test system in Real Time., "Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.", Intelligent Electrical Power Grids

To counter the inherent intermittent and unpre dictable power generation from large amounts of wind and solar, fast-acting resources are required, one of the options being sector coupling via power to gas devices. Industrial Power to Gas (IPtG) resources, such as an electrolyzer, represent an attractive solution to satisfy the rising energy flexibility needs of renewable-rich power systems. Since these electrolyzers can be asked to respond quickly following steep power ramps of renewables, it is imperative to understand their capabilities and limitations in fulfilling such requirements. The contribution of this paper is twofold. First, we introduce a detailed model of a Proton Exchange Membrane (PEM) electrolyzer suitable for power system flexibility studies. Second, using this model we assess large scale electrolyzer as a flexibility service provider (FSP) to the grid. To evaluate electrolyzer performance, we construct the V-I characteristic curve before and after simulating each test case to derive insights on the influence of time and dynamic operation on the electrolyzer system., Virtual/online event due to COVID-19 "Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.", Intelligent Electrical Power Grids

Recently, given the increased integration of renewables and growing uncertainty in demand, the wholesale market price has become highly volatile. Energy communities connected to the main electricity grid may be exposed to this increasing price volatility. Additionally, they may also be exposed to local network congestions, resulting in price spikes. Motivated by this problem, in this paper, we present a coordination mechanism between entities at the distribution grid to reduce price volatility. The mechanism relies on the concept of duality theory in mathematical programming through which explicit constraints can be imposed on the local electricity price. Constraining the dual variable related to price enables the quantification of the demand-side flexibility required to guarantee a certain price limit. We illustrate our approach with a case study of a congested distribution grid and an energy storage system as the source of the required demand-side flexibility. Through detailed simulations, we determine the optimal size and operation of the storage system required to constrain prices. An economic evaluation of the case study shows that the business case for providing the contracted flexibility with the storage system depends strongly on the chosen price limit., Energy & Industry, Intelligent Electrical Power Grids

A High Impedance Fault (HIF) in the power distribution systems remains mostly undetected by conventional protection schemes due to low fault currents. Apart from degrading the reliability of power supply to customers, HIF can impose a high cost on the utilities due to technical damages. The nonlinear and asymmetric nature of HIF makes its detection and identification very challenging. HIF signatures are in the form of minute-level distortions in the observable AC sinusoidal voltage and current waveforms but these signatures do not follow a clear pattern. In this paper, we present Advanced Distortion Detection Technique (ADDT), based on waveform analytics to distinguish and detect HIF. In addition, the ADDT analysis provides a fair assessment about the location and severity of HIF for efficient decision-making at the DSO level. ADDT is computationally lightweight and can be implemented in actual relays, hence it is enabled to provide an easy and cost-effective solution to HIF detection issues. ADDT robustness is tested in several simulation cases of interest using the IEEE-34 and IEEE-13 distribution test feeder systems in RTDS power system simulator. The test results successfully demonstrate the effectiveness and robustness of ADDT., "Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.", Intelligent Electrical Power Grids

The high proliferation of converter-dominated Distributed Renewable Energy Sources (DRESs) at the distribution grid level has gradually replaced the conventional synchronous generators (SGs) of the transmission system, resulting in emerging stability and security challenges. The inherent characteristics of the SGs are currently used for providing ancillary services (ASs), following the instructions of the Transmission System Operator, while the DRESs are obliged to offer specific system support functions, without being remunerated for these functions, but only for the energy they inject. This changing environment has prompted the integration of energy storage systems as a solution for transfusing new characteristics and elaborating their business in the electricity markets, while the smart grid infrastructure and the upcoming microgrid architectures contribute to the transformation of the distribution grid. This review investigates the existing ASs in transmission system with the respective markets (emphasizing the DRESs’ participation in these markets) and proposes new ASs at distribution grid level, with emphasis to inertial response, active power ramp rate control, frequency response, voltage regulation, fault contribution and harmonic mitigation. The market tools and mechanisms for the procurement of these ASs are presented evolving the existing role of the Operators. Finally, potential barriers in the technical, regulatory, and financial framework have been identified and analyzed., Intelligent Electrical Power Grids

Item does not contain fulltext, BACKGROUND: There is no consensus regarding the timing of dialysis therapy initiation for end-stage kidney disease (ESKD) in children. As studies investigating the association between timing of dialysis initiation and clinical outcomes are lacking, we aimed to study this relationship in a cohort of European children who started maintenance dialysis treatment. METHODS: We used data on 2963 children from 21 different countries included in the European Society of Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association Registry who started renal replacement therapy before 18 years of age between 2000 and 2014. We compared two groups according to the estimated glomerular filtration rate (eGFR) at start: eGFR >/=8 mL/min/1.73 m2 (early starters) and eGFR <8 mL/min/1.73 m2 (late starters). The primary outcomes were patient survival and access to transplantation. Secondary outcomes were growth and cardiovascular risk factors. Sensitivity analyses were performed to account for selection- and lead time-bias. RESULTS: The median eGFR at the start of dialysis was 6.1 for late versus 10.5 mL/min/1.73 m2 for early starters. Early starters were older [median: 11.0, interquartile range (IQR): 5.7-14.5 versus 9.4, IQR: 2.6-14.1 years]. There were no differences observed between the two groups in mortality and access to transplantation at 1, 2 and 5 years of follow-up. One-year evolution of height standard deviation scores was similar among the groups, whereas hypertension was more prevalent among late initiators. Sensitivity analyses resulted in similar findings. CONCLUSIONS: We found no evidence for a clinically relevant benefit of early start of dialysis in children with ESKD. Presence of cardiovascular risk factors, such as high blood pressure, should be taken into account when deciding to initiate or postpone dialysis in children with ESKD, as this affects the survival.

Cossembler (co-simulation assembler) is a rapid prototyping tool for co-simulation. The tool is created to expedite the process of co-simulation development for power and energy system studies targeting user groups of power engineers, energy consultants and grid operators. Instead of focusing on message encoding, transportation and synchronization, as many other co-simulation tools do, Cossembler emphasizes application-level functionalities which are of interest to the intended users (such as power flow studies, stability simulations, market simulations, etc.). Cossembler is a block modeling tool whose blocks reflect these main functionalities in power and energy sector. In this paper, we show the main characteristics of Cossembler architecture, discuss some of its advantages and disadvantages, and finally, show examples of its use., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

Given the complexity, scale and heterogeneity of modern power systems, many comprehensive simulation tasks are almost impossible to carry out without collaboration from multiple institutions. One way to approach collaborative simulation is through co-simulation. In this approach each institution contributes a model and the simulation is run distributedly. Co-simulation environments can be centrally orchestrated or decentrally orchestrated, each having its own set of advantages and challenges. In this paper we analyse the merits and challenges of co-simulation for collaborative simulation between institutions through two simple co-simulation environments, one centralized and the other decentralized. We argue that a co-simulation environment for collaboration between institutions should provide functionality like standard co-simulation interfaces for a variety of simulation tools, remote management and con?guration, model compatibility checks, and failure detection and recovery. An environment with these characteristics can be easily adopted by a wide range of institutions, which would greatly aid in tackling the complexity of modern electrical power systems., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

The complexity of energy systems increases as more renewable generation and energy storage technologies are added to the grid. Diverse energy carriers are becoming interconnected and the grids are getting reliant on communication networks for timely operation. The arising complexity is difficult to model with the existing mathematical models and using existing simulation tools due to confinement of these models and tools to a subset of the interconnected system. To overcome this challenge, combined simulation (co-simulation) methodology is being deployed. In co-simulation, multiple models and tools are being interconnected to truthfully represent reality. In this work, we review several aspects of co-simulation. First, we look at interconnecting transmission and distribution grid simulations in order to enable collaboration between transmission system operators (TSOs) and distribution system operators (DSOs). Next, we investigate co-simulation as means to dynamic model exchange between TSOs. Finally, we analyze co-simulation capabilities for running experiments in remotely connected research labs., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

DIgSILENT PowerFactory is among the most widely adopted power system analysis tools in research and industry. It provides a comprehensive library of device models and it allows users to define their own. Models for dynamic simulation can be defined in the DIgSILENT Simulation Language (DSL). When the functionality of DSL is insufficient, new DSL functions can be defined in C or C++. However, C and C++ can be challenging for inexperienced programmers. Furthermore, every time the C or C++ code is modified, it needs to be recompiled and PowerFactory needs to be restarted for the changes to take effect, which slows down the workflow, model development, and inhibits rapid prototyping. In this paper we present an open source library that allows users to call Python functions and methods from DSL with minimal effort. Python is a powerful and much easier to use language than C or C++. Additionally, Python programs do not need to be compiled. Furthermore, with this library PowerFactory does not need to be restarted every time the Python code is changed. To illustrate what can be accomplished with our library we present three example use cases related to load modeling, co-simulation, and fault detection based on machine learning. The examples show that it becomes straightforward to enhance DSL with Python and that sophisticated models can be produced with reduced effort using popular open source Python libraries. As a consequence, PowerFactory users gain access to enhanced modeling capabilities and user-friendliness, and a more speedy workflow, which is beneficial for rapid prototyping., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

Improved modeling and simulation of power and energy systems has become increasingly important in the face of energy transition. The main challenge is to capture the complexity that heterogeneity of technologies and uncertainty of renewable resources bring along. One approach to improve simulation modeling capabilities, that relies on reusing existing expertise and legacy tools, is a so-called combined simulation (co-simulation). In this approach, well-established tools are combined together resulting in simulation environments with greater capabilities. In this paper, we introduce a new cosimulation rapid prototyping tool called Cossembler (which stands for Co-simulation assembler), whose main benefits are high usability and a variety of potential application domains that could be addressed by it. The paper further presents two use cases which illustrate Cossembler capabilities., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of renal failure. For several decades, ADPKD was regarded as an adult-onset disease. In the past decade, it has become more widely appreciated that the disease course begins in childhood. However, evidence-based guidelines on how to manage and approach children diagnosed with or at risk of ADPKD are lacking. Also, scoring systems to stratify patients into risk categories have been established only for adults. Overall, there are insufficient data on the clinical course during childhood. We therefore initiated the global ADPedKD project to establish a large international pediatric ADPKD cohort for deep characterization. Methods: Global ADPedKD is an international multicenter observational study focusing on childhood-diagnosed ADPKD. This collaborative project is based on interoperable Web-based databases, comprising 7 regional and independent but uniformly organized chapters, namely Africa, Asia, Australia, Europe, North America, South America, and the United Kingdom. In the database, a detailed basic data questionnaire, including genetics, is used in combination with data entry from follow-up visits, to provide both retrospective and prospective longitudinal data on clinical, radiologic, and laboratory findings, as well as therapeutic interventions. Discussion: The global ADPedKD initiative aims to characterize in detail the most extensive international pediatric ADPKD cohort reported to date, providing evidence for the development of unified diagnostic, follow-up, and treatment recommendations regarding modifiable disease factors. Moreover, this registry will serve as a platform for the development of clinical and/or biochemical markers predicting the risk of early and progressive disease.

Faster detection of faults, can lead to better and more efficient control of power system against cascading failures triggered by the faults. This article presents a novel detection algorithm using statistical methods for the detection of events that lead to FIDVR. Furthermore we show that the algorithm is computationally efficient and quick enough to provide the control inputs to an UVLS scheme using in-feed PMU data. Thus, it is ensured that the minimal level of load to be shed is determined on-the-fly as the event develops., "Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.", Intelligent Electrical Power Grids

Key contributor to normal power grid operations is optimal working of the various power grid equipment/apparatus. Nonoptimal operation of any of this equipment causes power quality problems which can pose great risk to the stability of the grid. Damaged or partially damaged equipment leaves characteristic signatures in the form of current and voltage waveform distortions. Detecting and localizing such signal distortions would contribute to grid reliability as the damaged equipment could be replaced in time before it can cause further damage. This paper proposes a Distortion Detection Technique (DDT) based on second-difference approach. This distortion detection technique has very low memory requirements and can be easily implemented on decentralized systems. The paper investigates the performance of this technique and evaluates it with case studies involving different kind of equipment failures simulated on Real Time Digital Simulator (RTDS)., Intelligent Electrical Power Grids

Locational Marginal Price (LMP) is a dual variable associated with supply-demand matching and represents the cost of delivering power to a particular location if the load at that location increases. In recent times it become more volatile due to increased integration of renewables that are intermittent. The issue of price volatility is further heightened during periods of grid congestion. Motivated by these problems, we propose a market design where, by constraining dual variables, we determine the amount of demand-side flexibility required to limit the rise of LMP. Through our proposed approach a price requesting load can specify its maximum willingness to pay for electricity and through demand-side flexibility hedge against price volatility. For achieving this, an organizational structure for flexibility management is proposed that exhibits the coordination required between the Distribution System Operator (DSO), an aggregator and the price requesting load. To demonstrate the viability of our proposed formulation, we run an illustrative simulation under infinite and finite line capacities., Energy & Industry, Intelligent Electrical Power Grids

Energy flexibility is key to integrating more renewables into the grid. An essential contributor to enabling energy flexibility is P2X technologies such a Power2Heat, Power2Gas, among others. To evaluate the flexibility available from these resources and the impact they can have on the electrical grid, complex simulations need to be set up that may not always be possible using traditional simulation tools, given the multi-domain nature of such systems. Hence, the need for intelligent simulation techniques arises. This paper introduces a co-simulation tool, FMUWorld, to overcome simulation problems for complex energy systems. We use a multi-energy co-simulation and an energy flexibility analysis as use cases to explore the capabilities of the proposed tool. The ease-of-use offered by FMUWorld is shown to allow users to focus more on analysis of the system, such as parameter sensitivity, system optimisation, etc., rather than co-simulation setup. The paper highlights the key features and functionalities of FMUWorld that make it a novel tool for cosimulation of multi-energy systems., "Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.", Intelligent Electrical Power Grids

System Engineering, Policy Analysis, Energy & Industry, Intelligent Electrical Power Grids

Co-simulation has become increasingly popular as a tool for dealing with the unprecedented complexity of modern engineering systems, such as electrical power systems and the AC circuits that compose them. Co-simulation is useful when migrating the models of each subsystem to a single monolithic simulator is either impractical or impossible, and the need for understanding the interactions between the subsystems does not leave room for model simplifications. However, co-simulation can suffer from long execution times, caused by the overhead introduced by exchanging variables between simulators. In this paper, we propose a method that mitigates this overhead by decoupling the simulators whenever their inputs become predictable. We applied this method to the co-simulation of an AC circuit composed of two subsystems and obtained speedups of up to 39% with errors that remain around 1% most of the time. Although questions regarding the scalability of the method persist, these results indicate that the method has the potential to make co-simulation an even more valuable tool for the user., Intelligent Electrical Power Grids

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of renal failure. For several decades, ADPKD was regarded as an adult-onset disease. In the past decade, it has become more widely appreciated that the disease course begins in childhood. However, evidence-based guidelines on how to manage and approach children diagnosed with or at risk of ADPKD are lacking. Also, scoring systems to stratify patients into risk categories have been established only for adults. Overall, there are insufficient data on the clinical course during childhood. We therefore initiated the global ADPedKD project to establish a large international pediatric ADPKD cohort for deep characterization. METHODS: Global ADPedKD is an international multicenter observational study focusing on childhood-diagnosed ADPKD. This collaborative project is based on interoperable Web-based databases, comprising 7 regional and independent but uniformly organized chapters, namely Africa, Asia, Australia, Europe, North America, South America, and the United Kingdom. In the database, a detailed basic data questionnaire, including genetics, is used in combination with data entry from follow-up visits, to provide both retrospective and prospective longitudinal data on clinical, radiologic, and laboratory findings, as well as therapeutic interventions. DISCUSSION: The global ADPedKD initiative aims to characterize in detail the most extensive international pediatric ADPKD cohort reported to date, providing evidence for the development of unified diagnostic, follow-up, and treatment recommendations regarding modifiable disease factors. Moreover, this registry will serve as a platform for the development of clinical and/or biochemical markers predicting the risk of early and progressive disease.

Evaluating new technological developments for energy systems is becoming more and more complex. The overall application environment is a continuously growing and interconnected cyber-physical system so that analytical assessment is practically impossible to realize. Consequently, new solutions must be evaluated in simulation studies. Due to the interdisciplinarity of the simulation scenarios, various heterogeneous tools must be connected. This approach is known as co-simulation. During the last years, different approaches have been developed or adapted for applications in energy systems. In this paper, two co-simulation approaches are compared that follow generic, versatile concepts. The tool mosaik, which has been explicitly developed for the purpose of co-simulation in complex energy systems, is compared to the High Level Architecture (HLA), which possesses a domain-independent scope but is often employed in the energy domain. The comparison is twofold, considering the tools’ conceptual architectures as well as results from the simulation of representative test cases. It suggests that mosaik may be the better choice for entry-level, prototypical co-simulation while HLA is more suited for complex and extensive studies., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids

Predictive mitigation of undesired events has long been seen as a supportive complement to corrective mitigation that could relax the stringent requirements on the corrective actions and increase reliability of the overall system. This article describes one such predictive measure, i.e. the use of faster than real-time simulation in detecting faults and predicting the dynamic behavior for the resilient operation of future smart grid systems. A predictive mitigation strategy is proposed for a fault induced dynamic voltage recovery (FIDVR) event. These events, although rare, are typically addressed with under voltage load shedding schemes (UVLS) which leave significant portion of load under-supplied. We show that, by using the digital faster than real-time replica, the minimal level of UVLS can be determined on-the fly as the event develops while ensuring only the minimal amount of load shed., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Electrical Power Grids