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Owing to its essential features, such as modularity and exceptional power quality, the modular multilevel converter (MMC) emerges as the optimal converter topology for high-voltage direct current (HVDC) applications. Traditionally, MMCs are controlled through a method called nearest level modulation (NLM), which generates N+1 AC output voltages, where N represents the number of sub modules (SMs) per arm. In this paper, we introduce a modified NLM technique designed to yield 2N+1 and 4N+1 levels, with a focus on efficiently controlling internal dynamics. The proposed MMC is evaluated using a hardware-in-the-loop (HIL) environment to obtain real-time simulation outcomes. This MMC topology demonstrates a reduction in circulating currents and capacitor voltage ripple. [ABSTRACT FROM AUTHOR]

This paper develops a multi agent system in real time for hybrid microgrids as advanced energy management (ADEM) protocol using a Java agent development environment (JADE) frame work. The proposed system is configured with two micro-grids, each having 1kw solar photo voltaic power, 1.5Kw wind power, 24 V, 150AH battery along with a local load, thus making it a hybrid Microgrid, modelled in MATLAB/Simulink. Due stability constraints while using MATLAB/Simulink, in a multi-threading environment, a middle ware called Multi agent Control Using Simulink with Jade Extension (MACSimJX) is adopted. The microgrid environment variables are captured through sensors, delivered to the agents operations in JADE, for the implementation of dynamic operation in hybrid microgrids. This results in maximizing operational efficiency of hybrid microgrids system. The simulation suggests that MAS can successfully manage dynamic loads, generated power in real time microgrids.

Hybrid electric vehicle (HEV) is one of the ideal transportation tools to face the challenge of ‘Carbon peak carbon neutralization’. The high complexity of the latest HEVs result to the difficulties in vehicle fault diagnostics, which is considered to be the main factors of vehicle durability. In this study, a multi-fault mode detection method of a P2 diesel HEV was investigated by using support vector machine(SVM). The HEV physical model was built and validated by using the experimental data under China typical urban driving cycle (CTUDC). The SVM algorithm was coded in Matlab/Simulink environment. The training data vectors for normal mode and fault mode were acquired from the HEV model. Through the analysis of failure mode, the OVO-SVM method was proved as the best accuracy, the success rate of diagnosis reaches 98%. Case studies of single fault mode and multi-fault mode fault detection were conducted. Offline and online level test were performed to show the effectiveness of the detection algorithm. The study may support the development of intelligent diagnostic methods for the different types of HEVs.

This article proposes a new method of modelling dynamic loads based on instantaneous p-q theory, to be employed in large powers system network simulations in a digital real-time environment. Due to the use of computationally heavy blocks such as phase-locked-loop (PLL), mean calculation,and coordinate transformation blocks (e.g., abc–dq0), real-time simulation of large networks with dynamic loads can be challenging. In order to decrease the computational burden associated to the dynamic load modelling, a p-q theory-based approach for load modelling is proposed in this paper. This approach is based on the well-known p-q instantaneous theory developed for power electronics converters, and it consists only of linear controllers and of a minimal usage of control loops, reducing the required computational power. This improves real-time performance and allows larger scale simulations. The introduced p-q theory-based load (PQL) model has been tested on standard networks implemented in a digital real time simulator, such as the SimBench semi-urban medium voltage network and the 118-bus Distribution System, showing significant improvement in terms of computational capability with respect to standard load models (e.g., MATLAB/Simulink dynamic load).

Micro‐grid islanding methods are gaining importance as the presence of renewable energy resources is becoming increasingly popular in power distribution. Among all the islanding methods, passive methods are easy to implement and applicable to all types of DERs provided the NDZ is minimized. This article presents a novel passive islanding detection method based on the CSoDoA of ellipse formed by the successive phase voltages to address the NDZ problem. The peak magnitude and phase angle difference of voltages are the parameters to be estimated to compute the area of the ellipse. State‐of‐the‐art passive methods consider the effect of either magnitude or phase angle or frequency as an islanding detection metric. The CSoDoA metric combines the effect of both magnitude and phase angle thereby reducing the NDZ. The proposed method is validated on both synchronous and inverter‐interfaced DERs. The test systems considered are both single‐DER based MG and modified IEEE 13 bus multi‐DER MG. The CSoDoA algorithm is implemented on a Raspberry‐Pi controller and validated using HIL workbench with real‐time simulator OP‐4510. Various islanding and non‐islanding events are simulated, tested and it is evident from the results that it has a very small NDZ. [ABSTRACT FROM AUTHOR]

Despite the existence of computationally efficient tools, the effort for parametric investigations is currently high in industry. In this paper, within the context of Li-Ion batteries, an efficient meta-modelling approach based on the Proper Generalized Decomposition (PGD) is considered. From a suitable design of experiments, a parametric model is trained and then exploited to predict, in real time, the system response to a specific parameter combination. In particular, two different methods are considered, the sparse PGD (sPGD) and the anchored-ANOVA based one (ANOVA-PGD). As a use case for the method the dynamic indentation test of a commercial lithium-ion pouch cell with a cylindrical impactor is selected. The cell model considers a homogenised macroscopic structure suitably calibrated for explicit finite element simulations. Four parameters concerning the impactor are varied, both non-geometric (mass and initial velocity) and geometric (diameter and orientation). The study focuses on multi-dimensional outputs, such as curves and contour plots. Inspired by earlier studies, the sPGD is used to predict the force-displacement curves. As a further development, the impactor kinetic energy curve and the displacement contours are both predicted using its recently developed variant ANOVA-PGD. Moreover, a novel curve alignment technique based on the Gappy Proper Orthogonal Decomposition (Gappy-POD) is suggested here. The meta-model is compared to the results of an FE simulation and the resulting deviations are then discussed.

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The trend toward higher switching frequency and larger scale of power electronic systems poses challenges for real-time simulation. This article presents an event-driven hardware-in-the-loop (ED-HIL) simulation framework that does not rely on the small fixed simulation step-size related to the switching frequency. ED-HIL framework can improve the calculation efficiency by positioning switch events and using variable simulation step-size. Further, a parallel acceleration and circuit partitioning (PACP) solver is proposed based on this framework. The PACP solver partitions the circuit with energy storage elements and ensures that the partitioning does not introduce simulation distortion by using the higher order derivatives of the energy storage elements. Meanwhile, it achieves a process-level paralleling through a shared memory architecture in order to accelerate the simulation. As a result, the proposed PACP solver based on the ED-HIL framework can achieve about three times the simulation scale of a commercial FPGA-based real-time simulator at 1/16 the hardware cost under the same conditions. An accurate real-time HIL example of a power electronic transformer with 32 switches at a switching frequency of 20 kHz has been implemented on a personal computer. The simulation results are analyzed by comparing with experiment, offline software, and commercial real-time simulator. [ABSTRACT FROM AUTHOR]

Investigations of the dynamic behaviour of power electronic components integrated into electric networks require suitable and established simulation methodologies. Real-time simulation represents a frequently applied methodology for analyzing the steady-state and transient behavior of electric power systems. This work introduces a guideline on how to model power electronics converters in digital real time simulators, taking into account the trade-off between model accuracy and the required computation time. Based on this concept, possible execution approaches with respect to the usage of central processing unit and field-programmable gate array components are highlighted. Simulation test scenario, such as primary frequency regulation and low voltage ride through, have been performed and accuracy indices are discussed for each implemented real-time model and each test scenario, respectively. Finally, a run-time analysis of presented real-time setups is given and real-time simulation results are compared. This manuscript demonstrates important differences in real-time simulation modelling, providing useful guidelines for the decision making of power engineers.

The arrival of the energy transition to the global electricity scene has led to the implementation of new technologies in power systems and modified the way that the energy is generated, distributed and consumed. The analysis of the operation and the consequences of the inclusion of new technologies become a very important topic in the studies carried out by the utilities. Real-Time Digital Simulators (RTDS) have become a powerful modeling tool that allow to analyze power system models with a high level of fidelity, permitting to anticipate problems and the assessment of solution strategies. Due to the increase in the use of this technology and considering that there are no review articles on RTDS applications written in Spanish, this paper presents an explanation of the characteristics of RTDS along with an updated state of the art related to applications in Energy Transition as a theoretical framework with a large amount of information collected for future researches in Latin America. [ABSTRACT FROM AUTHOR]

The paper is focused on the development of the digital twin of the hydraulic control valve for continuous control of the oil flow -- servovalve or control valve -- and their use by the testing of the control system of the test rig for the measurement and evaluation of the characteristics of the valve. The structure of the mathematical model of the control valve enables to do the parameterisation for different types and sizes of the control valves only using the catalogue data delivered by the valve producers. In the next step the created and parameterized model is implemented into the dSpace MicroLabBox for the real time realisation of the digital twin. The MicroLabBox is equipped with the analogue inputs and outputs and allows the connection of the digital twin to the control system in the same way as the real servovalve. Finally, the characteristics of the valve are measured and evaluated using the HiL simulation of the digital twin. The digital twin of the servovalve allows the testing of the developed control system and software for the hydraulic test rig for the measurement of the valve characteristics without the need of the real valves different types. [ABSTRACT FROM AUTHOR]

The potential capabilities of Autonomous Underwater Vehicle (AUV) compared to traditional tools and equipment have led to increased attention and use of underwater vehicles in various commercial, military, and research fields. The manufacture and development of an offshore operational platform require the design of a complete and expensive system of a maritime laboratory in order for evaluating and validating the characteristics and performance of the integrated system and its subsystems. Modeling can be a cost-effective tool for conducting tests, verifying and certifying components and performance of hardware and software, performing missions, and thus reducing potential errors in marine tests and missions. These goals can be achieved through a relatively accurate dynamic simulation and modeling of equipment and environmental conditions inside the hardware in the loop (HIL) laboratory. The purpose of this paper is to provide real-time modeling and implement a physics-based depth environmental simulator for an AUV to equip the HIL laboratory. Validation of the performance of the depth environmental simulator in the dynamic bed of six degrees of freedom of an Autonomous Underwater Vehicle crawler has been done in real-time. The results indicate that the output of the depth environmental mechanism matches the measured depth of the field experiment at sea and there is no delay and bias between the real and simulated signal.

Real Time Simulation (RTS) has long been used in the nuclear power industry for operator training and engineering purposes. And, Online Simulation (OLS) is based on RTS and with connection to the plant information system to acquire the measurement data in real time for calibrating the simulation models and following plant operation, for the purposes of analyzing plant events and providing indicative signs of malfunctioning. An OLS system has been developed to support PWR operations for CPR1000 plants. The OLS system provides graphical user interface (GUI) for operators to monitor critical plant operations for preventing faulty operation or analyzing plant events. Functionalities of the OLS system are depicted through the maneuvering of the GUI for various OLS functional modules in the system.

To determine the impact of emergent transition from in-person to remote learning on student performance within real-time objective structured clinical examinations (OSCEs). A university mandate, due to severe SARS-CoV-2, was issued requiring didactic courses to transition to remote learning in spring 2020. The third-year internal medicine elective had six remaining weekly OSCEs, accounting for 55% of course grades. Full credit was awarded for the first OSCE as students familiarized themselves with the new virtual format. The primary outcome was the overall average OSCE performance for the course's remaining five virtual simulations compared to the traditional in-person offering in 2019. Secondary outcomes included individual OSCE performance, OSCE performance with inclusion of the first OSCE, and overall course grades. There were no statistically significant differences in overall average OSCE performance between 2019 and 2020 cohorts for the five simulations (82.7% vs. 86.8%, P =.20). Secondary outcomes showed statistically significant differences favoring performance in the 2020 cohort for infectious diseases (78.3% vs. 89.4%, P <.001) and anticoagulation (74.4% vs. 90%, P =.002), while cardiology favored the 2019 cohort (91.1% vs. 82.8%, P =.03). There was no statistically significant difference in performance on the cumulative I (86.1% vs. 82.2%, P =.41) or cumulative II (83.3% vs. 89.4%, P =.29) simulations or in final overall course grades (86.6% vs. 90.2%, P =.06). An emergent transition to remote learning may not negatively impact student performance on real-time OSCE activities. [ABSTRACT FROM AUTHOR]

Economic dispatch in the presence of wind farms is of high interest in power system operational planning. Due to the uncertainty of wind speed and wind power, a probabilistic model is needed for application in economic dispatch solution. The weibull probability distribution function is a common tool to model wind speed probabilistic behavior, but the main challenge is the nonlinearity of wind power generation with respect to wind speed. This causes complexity in probabilistic economic dispatch, which can lead to numerical and time-consuming solution methods. Therefore, linearization of the wind power curve is in the interest of some methods by simply connecting the first point to end point of power curve by a straight line. In this paper, by developing a conventional objective function for ED solution, two main contributions are made to obtain a suitable method for fast and also good accuracy results in real time purposes. At first, an improved method for linearization of wind power curve with respect to previous works is introduced which increases the performance of modelling with respect to the nonlinear model as the base model. The second contribution is developing an analytical routine for economic dispatch by an acceptable time-consuming calculation suitable for real time purposes. The effectiveness of the new approach has been tested on two test systems. The results show the improvement in relative error in ED cost with respect to real nonlinear curve model which reduces the error about one fifth regard to the conventional linearization model.

Aircraft ground braking control is a complex time-varying dynamic problem, especially when there are unexpected disturbances from lateral wind or visual error. Therefore, under some extreme conditions, it is hard for the pilot to control aircraft braking as well as usual without assistant control. This paper solves this problem by proposing a novel assistant control for aircraft ground braking, mainly based on the pilot control model and the LPV theory. And in order to reflect the control characteristics of the pilot, the sensory and control-theoretic model were combined together for controller designing. To test the performance of proposed control method, a real time pilot-in-loop simulation system is constructed. According to experiment results, the proposed assistant control shows better performance than pilot control, for it not only help the pilot to resist disturbance, but also hardly run counter to the pilot's intent.

The discrete element method (DEM) is widely used to tackle problems associated with granular material processing. Its applications are diverse, ranging from powder mixing to transport and fluidized beds. Computational costs are a major issue with regard to DEM. Long process times combined with a large numbers of particles require simulations that can last months. In this paper we apply an extrapolation method based on pseudo-steady state DEM bulk behavior to allow for the long repetitive process to be completed. The extrapolation method is applied to two processes relevant to the pharmaceutical industry: continuous mixing and a tablet press feed frame. The results of the extrapolation method are validated against full DEM simulations of the complete process in terms of residence time, travel distance, and velocity distributions. The DEM extrapolation for pseudo-steady state processes resulted in an enormous reduction of the simulation time, while retaining residence times, travel distance and velocity distributions. [Display omitted] • DEM extrapolation applied for continuous processes. • Comparison between conventional DEM and DEM extrapolation. • Analysis of residence time, distances travelled by particles and velocities. • Very good agreement between both DEM and DEM extrapolation. • Massive speed-up possible. [ABSTRACT FROM AUTHOR]

This paper develops a multi agent system in real time for hybrid microgrids as advanced energy management (ADEM) protocol using a Java agent development environment (JADE) frame work. The proposed system is configured with two micro-grids, each having 1kw solar photo voltaic power, 1.5Kw wind power, 24 V, 150AH battery along with a local load, thus making it a hybrid Microgrid, modelled in MATLAB/Simulink. Due stability constraints while using MATLAB/Simulink, in a multi-threading environment, a middle ware called Multi agent Control Using Simulink with Jade Extension (MACSimJX) is adopted. The microgrid environment variables are captured through sensors, delivered to the agents operations in JADE, for the implementation of dynamic operation in hybrid microgrids. This results in maximizing operational efficiency of hybrid microgrids system. The simulation suggests that MAS can successfully manage dynamic loads, generated power in real time microgrids. [ABSTRACT FROM AUTHOR]

The Quai des Trois Fontaines is a berthing area in Chooz, France, which was designed for 80 m long vessels (CEMT Class IV) plying the River Meuse. A turning basin is located in front of the Quai des Trois Fontaines to allow vessels to turn before loading at the quay. Real time simulations on a dedicated inland ship manoeuvring simulator at Flanders Hydraulics Research were carried out with experienced skippers to study how the safety of the turning manoeuvre could be improved and which measures are required for safe manoeuvres with longer vessels, i.e. vessels of 85 and 90 m in length. In the first phase of the study, turning manoeuvres of CEMT Class IV vessels of 80 m, 85 m and 90 m long were studied in the existing environment. The manoeuvres were evaluated based on different safety criteria and on the feedback of the pilots. The real time simulations have shown that the actual design of the turning basin is suitable for the 80 m long vessels in any hydro-meteorological condition. However, the manoeuvres become risky with 85 m long vessels under certain conditions and impossible with longer ships. Although the current can be very strong on the river Meuse, the local width turned out to be the most critical parameter. In the second phase of the study, measures were proposed to allow the safe turning of 85 m and 90 m long vessels. Local widening of the river to 100 m and to 105 m were proposed for 85 m and 90 m long ships respectively. A third proposed measure is to provide a fixed point near the end of the quay, to which the vessels can attach and around which they can then turn.

This article assesses the impact on the Power Quality produced by the interconnection of a microgrid to a transmission system, real-time simulation have been used to carry out the study, applying national and international power quality standards, IEEE 1547 of 2018, IEEE 519 of 2014 and NTC 5001 of 2008. The phenomena of voltage harmonics, current harmonics, flicker and DC injection were evaluated on a microgrid case study. The results show that the interconnection of the microgrid produces a high impact on the current harmonics and the DC injection of the local transmission system, while the flicker phenomena and voltage harmonics have a smaller impact.

With the requirements of hardware-in-the-loop（ HIL） test of dual clutch Automatic transmission（ DCT） control unit（ TCU）,the real time simulation model of DCT is built based on Matlab/Simulink,mainly containing shift fork position,clutch torque,transmission torque and speed synchronization calculation modules,etc. The functional fault model module is developed on the basis of the real time model to realize the simulation of mechanical failures. The built DCT model is integrated into the whole vehicle model,a closed loop is constituted with real TCU,and the DCT model is validated online. The built model can be effectively used for the function and fail-safe testing of DCT-TCU.

This paper investigates the response to grid disturbances of the wind energy conversion system based on the doubly fed induction generator (DFIG-based WECS). It is proposed a new control termed as heightened state-feedback control structure (HSFC) with predictive behavior to regulate the rotor current loops, which is able to effectively counteract the back electromotive force surge oscillating dynamics that occur in the event of a disturbance in the grid voltage. The proposed method is able to mitigate oscillations in DFIG currents exempting the need to use low voltage ride-through current-modify (LVRT-CM) strategies during intermediate symmetrical and asymmetrical voltage sags or during the voltage recovery process, while provide the DFIG to contribute active and reactive current featuring bounded torque oscillations. During severe faults, the proposed structure is able to effectively track the required post-fault rotor current references as demanded by LVRT-CM, which allows the DFIG to ride-through the fault with constrained currents and torque. The proposed structure also employs a novel flux damping technique which accentuate the rotor d-axis current in order to significantly reduce stator flux settling time after faults, while the torque minimally oscillates during post-fault recovery. Real-time digital simulations and experimental results considering symmetrical and asymmetrical voltage sags due to faults show the proposed solutions advantages over classical and previous strategies. [ABSTRACT FROM AUTHOR]

This article presents the simulation of a BLDC motor and its closed control system in FPGA. The simulation is based on a mathematical model of the motor, including the electromagnetic torque, phase currents, back electromotive force, etc. In order to ensure calculation precision, the equations describing the motor were solved using a floating point representation of real numbers, and a small step of numerical calculations of 1 μs was assumed. The time step selection methodology has been discussed in detail. The motor model was executed with the use of Textual Programming Languages (with HDL codes).

Thirst for energy is increasing significantly with increase in economy around the world which burdens conventional grid (CG) due to peak demand, energy deficit, and carbon emission, but major part of continents has plentiful wind and solar energy which can be harnessed locally to minimize it. Major objective of this research is to reduce the peak power deficit present in CG system and to provide a reliable power supply even in case of grid failure or during blackout. In this paper, development and evaluation of a small scale grid interactive dc microgrid for residential houses, telecommunication systems, and data center has been proposed. The objective is being achieved by designing a comprehensive power flow control strategy and explored for different practical scenarios through real time simulation in RSCAD/RTDS platform. A prototype is developed to validate the simulation results presented during grid connected and isolated mode. [ABSTRACT FROM AUTHOR]

In this paper, modeling, analysis, design and simulation of a POSICAST controller are presented for application in a generator's excitation system. Simple structure is the most important characteristic of this controller. The controller is a feedforward compensator; it eliminates intensive over/undershoots in system dynamic response. Since changing the reference signal in the excitation system of the synchronous generator causes oscillations in the terminal voltage, the POSICAST controller (PC) is applied at the outset of the excitation system to mitigate these oscillations. The impact of the proposed controller on the stability of the studied power system is evaluated by both eigenvalues analysis and experimental results. In order to validate the theory, the performance of the designed controller is verified in OPAL-RT by experimental approach. [ABSTRACT FROM AUTHOR]

Microgrids today include more and more renewable sources both for environmental and economic reasons. The advantage of microgrids is their capacity of running isolated. The presence of largely uncontrollable sources (PV plants and wind farms) makes the grid control a complex task. During the design stage it is mandatory to consider the expected variations of both loads and sources to identify proper solution for stabilizing the Microgrid when it runs isolated. The paper presents a simulator that was developed to support the design of the Microgrid both in terms of power devices and control techniques. The main goal of this simulator is to test the automation system of the Microgrid before its site installation. The simulator calculates the dynamic behavior of conventional generators, renewable source, and loads. The model of renewable sources includes the expected power variations as well as the random profile of loads. If required, energy storage systems can be integrated in the simulator. All the control set-point of controllable equipment and the calculated frequency and voltage of the Microgrid are interfaced with the control system using a standard Ethernet-base fieldbus. Such a solution makes it possible to study different control logics and to tune the control parameters of the system using the real control system. The data exchange between the simulator and the control system is identical to the real data flow that will be found in the Microgrid. With the use of the simulator, the control system of the Microgrid is implemented during the design stage, with reduced development, testing, and commissioning times. [ABSTRACT FROM AUTHOR]

Renewable integrated dc Microgrids (DCMGs) are gaining popularity by feeding remote locations in qualitative and quantitative manner. Reliability of autonomous dc microgrids depend on battery capacity and size due to stochastic behavior of renewables. Over charging and discharging scenarios compel the microgrid into insecure zone. Increasing the storage capacity is not an economical solution because of additional maintenance and capital cost. Thus, interconnecting neighbor microgrids increases virtual storing and discharging capacity when excess power and deficit scenario arises respectively in any of the DCMG. Control strategy plays vital role in regulating the power within and between microgrids. Power control and management technique is developed based on bus signaling method to govern sources, storages, and loads to achieve effective coordination and energy management between microgrids. Proposed scheme is simple and reliable since bus voltages are utilized in shifting the modes without having dedicated communication lines. Proposed scheme is validated through real time simulation of two autonomous dc grids in real time digital simulator (RTDS) and its results are verified by hardware experimentation. [ABSTRACT FROM AUTHOR]

This paper presents modeling and study of 12-pulse HVDC (High Voltage Direct Current) based on real time simulation where the HVDC inverter is connected to a weak AC system. In goal to study the dynamic performance of the HVDC link, two serious kind of disturbance are applied at HVDC converters where the first one is the single phase to ground AC fault and the second one is the DC link to ground fault. The study is based on two different mode of analysis, which the first is to test the performance of the DC control and the second is focalized to study the effect of the protection function on the system behavior. This real time simulation considers the strength of the AC system to witch is connected and his relativity with the capacity of the DC link. The results obtained are validated by means of RT-lab platform using digital Real time simulator Hypersim (OP-5600), the results carried out show the effect of the DC control and the influence of the protection function to reduce the probability of commutation failures and also for helping inverter to take out from commutation failure even while the DC control fails to eliminate them. [ABSTRACT FROM AUTHOR]