MATLAB Simulink Model Research Articles

Sensitivity study of parameters important to Molten Salt Reactor Safety

This paper presents a molten salt reactor (MSR) design parameter sensitivity study using a nodal dynamic modelling methodology with explicitly modified point kinetics equation and Mann’s model for heat transfer. Six parameters that can impact MSR safety are evaluated. A MATLAB-Simulink model inspired by Thorcon’s 550MWth MSR is used for parameter evaluations. A safety envelope was formed to encapsulate power, maximum and minimum temperature, and temperature-induced reactivity feedback. The parameters are perturbed by ±30%. The parameters were then ranked by their subsequent impact on the considered safety envelope, which ranks acceptable parameter uncertainty. The model is openly available on GitHub.

Distributed wind-hybrid microgrids with autonomous controls and forecasting

Distributed wind-hybrid microgrids have the potential to provide key resilience and economic benefits to both the customers they serve and the utility grids they are connected to. Such microgrids will likely be a key part of the grid of the future, whether connected to large utility grids or linked together in multi-microgrid systems. Through the hybridization of distributed wind and solar photovoltaics, autonomous device-level and system-level controls, battery energy storage systems with smart inverters, and forecasting, these microgrids could maintain local stability and provide grid services—all with renewable power. In the literature, these elements have been considered individually. However, they have not been combined and demonstrated at a high fidelity, which is essential to prove the concept’s operation before moving to hardware-in-the-loop and physical demonstrations. In this work, we develop a high-fidelity MATLAB-Simulink model of a real distributed wind-hybrid microgrid that includes all these elements. We demonstrate the microgrid maintaining stability and production in a variety of islanded, grid-connected, and transition scenarios. This includes riding through faults and grid transitions, handling resource variability, and providing grid services. The results demonstrate, at a high fidelity, how distributed wind-hybrid microgrids can operate in an economic and resilient fashion. Finally, we provide recommendations for future research to move advanced distributed wind-hybrid microgrids toward deployment.

Adaptive nonlinear current controller for switched reluctance motor torque ripple optimization

This paper deals with torque ripple minimization in SRM through adaptive nonlinear current control while considering saturation. The proposed methodology for SRM speed tracking is based on Indirect Instantaneous Torque Control (IITC). Optimal references are determined offline using the Particle Swarm Optimization (PSO) algorithm. The optimal current profile is generated by using current sharing function (CSF) block. The nonlinear speed and current controllers are developed using Backstepping technique. The proposed control strategy performance is evaluated using a Matlab Simulink model taking into account the saturation phenomena. The obtained results demonstrate that the adaptation of the control angles as well as the peak current minimizes the torque ripples for different operating conditions.

Laser Measurement and Numerical Simulation of Elastomer Stopper Motion during High-Altitude Shipping of Pharmaceutical Syringes.

During high-altitude shipping of pre-filled syringes, pressure differentials can cause the elastomer stopper to move unintentionally. This motion represents a risk to container closure integrity and drug product sterility. To understand and quantitate this risk, we combined high-accuracy laser measurements and numerical simulations of stopper motion. We tested the effects of syringe barrel siliconization, stopper design, syringe orientation, and altitude rate on stopper displacement; only the siliconization factor had a significant effect. Our observations were compared with two mathematical models based on Boyle's Law and a force balance approach. For well-lubricated syringes, stopper motion was reasonably predicted by Boyle's Law (residual ≤ 10%). When the lubricant amount was reduced, Boyle's Law failed to accurately predict stopper motion (residual ≈ 40%). To simulate stopper motion more accurately, we developed a dynamic model in MATLAB-Simulink to incorporate the dry and viscous friction inherent to the lubricated interference fit. Using a Coulomb-viscous subroutine, deviations from Boyle's Law were successfully explained in terms of the displacement, but the system dynamics were not fully accurate. The combination of laser measurements and numerical simulation has yielded unique insight into stopper motion during high-altitude shipping. These tools can provide valuable input to a risk-based drug development strategy to enable global distribution of pre-filled syringes.

Моделирование электропривода с многофункциональным ротором сепаратора полидисперсных жидких систем

Рассмотрено воздействие входных задаваемых факторов на выходные независимые параметры электропривода с многофункциональным ротором сепаратора для полидисперсных жидких систем. Эксперименты проведены с использованием математической модели в MatlabSimulink, их оптимальное количество определено по методу планирования. Установлены оптимальные значения амплитуды и частоты питающего напряжения по критерию максимума КПД и качеству продукта сепарирования с помощью метода идеальной точки. Воздействующие факторы подобраны как независимые друг от друга, диапазоны их варьирования заданы в пределах реальных величин, которые могут встретиться при эксплуатации электропривода с многофункциональным ротором сепаратора полидисперсных жидких систем.

An Innovative Converterless Solar PV Control Strategy for a Grid Connected Hybrid PV/Wind/Fuel-Cell System Coupled With Battery Energy Storage

The proposed work addresses the modeling, control, energy management and operation of hybrid grid connected system with wind-PV-Battery Energy Storage System (BESS) integrated with Fuel Cell (FC) and Electrolyzer. A hybrid PV-Wind-FC with electrolyzer consisting of BESS with the least number of control loops and converters has been proposed. The proposed hybrid system presents a cost efficient solution for integrating PV into a hybrid system by eliminating the PV converter. This includes the design of controllers for grid-connected hybrid systems with a renewable distributed generator (Wind and PV) as a primary source, BESS as a secondary source and FC with Electrolyzer as a tertiary source. In addition, the lead compensator along with integrator is used for obtaining enough phase margin and removing steady state error completely. It increases the stability of the controller and adds phase shift φ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>s</i></sub> at a cross gain frequency (ω <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>cut</i></sub> ). The Grid Side Controller (GSC) is capable of providing frequency support to the utility grid, when it is linked to the grid. In the proposed configuration, PV power is maximized and injected into grid through GSC. Rotor Side Converter (RSC) and GSC ensure the support for sharing the burden of the grid station. Moreover, the proposed controller of BESS with coordination of FC eliminates the effect of intermittency of power generated from wind and PV. Excess power production by renewable distribution generation is used by Electrolyzer to generate hydrogen. This hydrogen is further used by FC when there is not enough power generation due to unfavorable weather conditions. The energy management has been presented to fulfill the load profile, avoid BESS overcharging and to minimize the intermittency and fluctuation of Wind and PV sources. This method guarantees steady power flow and service continuity. The Simulink model of the proposed system results validate the efficiency of the proposed hybrid system as compared to the conventional hybrid system reported in the literature. The modeling of the proposed system and analysis has been demonstrated using the MATLAB Simulink model. Lastly, the energy management of the system has also been examined and compared with the conventional power system.

Implementation of an Alternative Frequency-Dependent Three-Phase Transmission Line Model Based on the Folded Line Equivalent Model in MatLab-Simulink

This paper proposes an alternative multiconductor transmission line model that combines the folded line equivalent with the modal transformation. The folded line equivalent decomposes the nodal admittance matrix of a transmission line into its open-circuit and short-circuit contributions. These contributions are fitted to rational functions, which are associated with Norton equivalent circuits based on their state space models. The proposed model uses an orthogonal matrix to transform voltages and currents from the phase domain to the folded line equivalent domain and vice versa. Because the transformation matrix is orthogonal, we represent it using ideal transformers in simulation software. First, we use a circuit representation of Clarke’s matrix to decompose a transmission line into its modes. Then, each mode is decomposed into its open-circuit and short-circuit contributions using a circuit implementation of the proposed matrix. The proposed approach can accurately represent short lines in simulations with time steps equal to or greater than the propagation time of the transmission line. We compare the results obtained with the proposed approach to those obtained with power systems computer-aided design/electromagnetic transients including the DC universal line model.

Design and Mathematical Modelling of Proton Exchange Membrane Fuel Cell used in Automobiles

The demand for electric vehicles is increasing day-by-day, considering a noise-free, pollution-free, and cost-efficient vehicle. But the fact that Electric Vehicles (EVs) cause less pollution than traditional IC-Engine Vehicles is not completely true, as switching to an electric vehicle produces an equal amount of pollution as in an IC-Engine vehicle. Charging an electric vehicle involves electrical energy from conventional thermal power plants, and Lithium-ion extraction and disposal pollute the air and land, respectively. The Electric Vehicle also has a lower driving range in comparison to the IC-Engine vehicles. Therefore, an alternative for both Electric and IC Engine vehicles that can significantly reduce environmental pollution and provide a better driving range is the need of the hour. Proton Exchange Membrane Fuel Cells or Polymer Electrolyte Membrane Fuel Cells (PEMFCs) will be an ideal solution to increase the driving range of the vehicle and reduce pollution. These fuel cells require hydrogen gas in a compressed state and oxygen from the atmosphere. The main objective of the research is to design and develop a PEM Fuel cell that can be used to achieve zero-emissions in automobiles. In this work, a mathematical model in MATLAB Simulink is used to simulate and test the PEM Fuel cell. The cell parameters, such as stack voltage and current density, are analyzed for various pressures, temperatures and humidification at the anode and cathode. It is observed that the model demonstrated the effect of reducing the relative humidity in both anode and cathode and results in the membrane became dry and highly resistive. So, at higher current density, more voltage drops in the fuel cell stack.

Experimental Evaluation of Adaptive Step-Size Based FxLMS Approach for Active Noise Control in Magnetic Resonance Imaging Systems

Magnetic Resonance Imaging (MRI) scanners emit up to 135 decibels of acoustic noise, which is a major source of discomfort for patients and personnel evaluating them during routine medical scans, necessitating the development of a method to reduce the acoustic noise generated during MRI testing. The goal of this study is to propose a frequency-domain Active Noise Control (ANC) method for acoustic noise reduction in MRI and to demonstrate its ANC effectiveness on an experimental MRI scanner model specifically built for this purpose. In comparison to the standard Least Mean Square (LMS) algorithm, we used the Filtered-x Least Mean Square (FxLMS) approach with an adaptive variable step-size approach to adjust the filter coefficients dynamically, which considerably enhances the ANC system's convergence and reduces acoustic noise. The simulation results obtained from the MATLAB Simulink model on a pre-recorded 30-sec MRI noise signal represented by the step-size variation over time, error and noise convergence plots reveal that the adaptive step-size FxLMS (ASFxLMS) technique increases noise and error convergence rate significantly more than existing ANC algorithms to facilitate its use during MRI scans. Experimental results with our functional MRI (fMRI) testbed show approximately 25-dB overall noise reduction relative to the noise levels without ANC.

Robust Pattern Recognition Based Fault Detection and Isolation Method for ABS Speed Sensor

Anti-lock braking system (ABS) is considered an essential safety system in electric vehicles that works to grant a reliable vehicle driving experience, and it is very important to ensure the security of such an onboard safety system. This work presents a detailed analysis associated with a comparison that includes several techniques based on pattern recognition for biasing fault detection in wheel and vehicle speed sensors. These techniques are K-nearest neighbor (KNN), support vector machine (SVM) and decision tree (DT), which were selected among other pattern recognition techniques that have been studied. The MATLAB Simulink model for the ABS system was implemented, and data was extracted from healthy and unhealthy operating conditions in order to be used to train each technique individually. An offline test was applied to these trained FDI models using the same implemented ABS Simulink model to express the performance of each one. Specifically speaking, accuracy and sensitivity were used in the algorithm’s efficiency comparison, with 99.9 % accuracy in the Fine KNN, 75 % accuracy in the Coarse Gaussian SVM, and 61.5 % accuracy in the Coarse Tree. From the result, and considering the ABS issues mentioned above, it can be concluded that the KNN classifier is superior to both the SVM and TREE classifiers.

A fuzzy-logic-based method for maintenance prioritization of high-voltage SF6 circuit breakers, considering uneven wear

High-voltage circuit breakers are among the most critical elements of the switching nodes of the power system. The localization of failures and the restoration of the normal operational mode of the power system are largely determined by the reliable operation of circuit breakers when switching off short circuit currents. This paper presents a fuzzy logic-based method to estimate the reliability of high-voltage SF6 circuit breakers and to set priorities for the maintenance schedule. In this method a realistic mathematical model is combined with a fuzzy inference system, and its effectiveness was tested with a MATLAB-Simulink model. Based on the simulation results, a preventive maintenance strategy for high-voltage SF6 circuit breakers can be proposed for particular operational states and conditions.

Development of unified diagnostic services on CAN using MATLAB and Arduino

Unified diagnostic service (UDS) is a standard developed by ISO which provides uniform services to automotive Electronic Control Unit (ECU) suppliers and manufacturers. With an ever-increasing number of ECUs in Automobiles, many diagnostic protocols such as Keyword Protocol (KWP) and Diagnostics over K-Line cause compatibility issues between them. Complexity multiplies when there is an increase in several functionalities of diagnostic software. The diagnostic tool enabled with UDS offers a standardized solution for diagnostics, debugging, and configuration of ECUs. This UDS application is implemented using Controller Area Network (CAN) Transport Protocol due to its reliability and robustness. This paper presents a UDS model in MATLAB-Simulink using a vehicle network toolbox and MATLAB Function block. Hardware implementation was done using Arduino Uno and MCP2515 CAN controller together acting as Client (Tester) and Server connected over CAN channel. Programming for hardware was done in Arduino IDE. The proposed model for UDS is effective and according to UDS standards.

Design of a bidirectional DC/DC converter for a hybrid electric drive system with dual-battery storing energy

Electric vehicles are projected to play an important role in the present and ensuing transportation as global environmental and energy issues become more serious. Looking into the growing popularity of electric vehicles, we need to pay even more attention to battery energy storage systems. Electric vehicles in the traditional sense rely on a battery to provide electricity. Influential requirements (acceleration and braking) will deteriorate the battery, or it may not be feasible to use it at all in some instances, due to the battery’s compactness. This paper proposes a Bidirectional DC/DC Converter topology and investigates its operation modes. The proposed converter can be used in hybrid electric vehicles. Hybrid electric vehicles use this converter type to connect a primary battery (ES1), an extra battery (ES2), and an adjustable voltage bus. Both step-up (i.e., Dual-source low-voltage powering mode) and step-down (i.e., energy-regenerating high-voltage dc-link mode) modes of operation are possible with the proposed converter, allowing bidirectional power flow. Furthermore, the model can handle the flow of electricity between any two low-voltage sources. For the proposed Bidirectional DC/DC Converter, two ways of power transmission, circuit design, and operation modes are analyzed. A MATLAB-Simulink model of the proposed, and the system is developed based on a Digital Signal Processor flow chart, and the results of the simulation as well as the performance of the system are discussed.

Fabrication and Mathematical Modeling of the Brushless Doubly Fed Induction Generator-Based Wind Electric Conversion System

Electricity generation with minimal environmental pollution is required for the world’s sustainable future, and wind electric generation is one of them. Brushless doubly fed induction generator (BDFIG), which derives from cascade induction machine technology, has grown in popularity as a wind electric generator due to advantages over doubly fed induction generator (DFIG) and permanent magnet synchronous generator (PMSG) such as the absence of slip rings and brushes and high-cost permanent magnets. Wind energy research is critical for any country’s economic development and long-term sustainability. As a result, an experimental setup in a laboratory is required to replicate the behaviour of a wind turbine in the steady state. This study discusses the emulation of wind turbine characteristics in the laboratory using a prototype of a separately excited DC motor mechanically coupled to a brushless doubly fed induction generator (BDFIG). The wind turbine emulator-brushless doubly fed induction machine (WTE-BDFIM) prototype was tested in the laboratory under high power and low wind speed conditions. As a result, the simulation of the same hardware configuration in MATLAB was performed to investigate the overall performance of the BDFIM-based WECS. To determine the equivalent circuit parameters of the BDFIM, which are required for simulation, tests were performed on a prototype of 3.5 kW, 2/6 pole, 400 V, star/delta-star, and BDFIM in two modes, namely, the simple induction mode and the cascade induction mode. Based on the BDFIM parameters, a MATLAB Simulink model of a BDFIG-based wind electric conversion system (WECS) is created and its performance is investigated. Results of both hardware and simulation show that BDFIG can be used as the wind electric generator over a wider speed range compared to that of DFIG, an important feature that is required to get maximum power extraction from the wind turbine.

Effectiveness of the method of two measurements in determining the parameters of equivalent circuits of electrical network elements for the highest harmon-ic components of currents and voltages

The feasibility of applying the method of two measurements in determining the parameters of equivalent circuits of electrical network elements for the highest harmonic components is analyzed. Experiments were carried out using a MATLAB Simulink model of the common coupling point that includes a distorting load in the form of a three-phase rectifier, a nondistorting linear load and a generalized power system without distortion sources. The parameters of an equivalent circuit in the form of active bipoles, consisting of current distortion and conductivity sources, were determined using the method of two measurements of mode parameters. Modes with variations in the active and reactive power of the studied distorting load and loads in the external electrical network were considered. The results of determining the equivalent circuit parameters under 20% and more variations in the power loading were established to be unstable (400% dispersion of actual values). Therefore, these parameter values appear to be unreliable due to their dependence on the value of external load power. At the same time, the simulation of random variations in loading parameters within 10% of the initial value allowed the parameters of an equivalent circuit to be correctly determined. It was shown that the equivalent circuit of a nondistorting linear load consists solely of conductivity, while the equivalent circuit of a distorting load can contain non-zero conductivity on the considered harmonic component. Thus, according to the performed study, the method of two measurements produces the results acceptable in terms of accuracy (deviation from actual values of less than 1%) not at a single significant variation in the mode parameters, but during a continuous monitoring of small natural variations in the parameters of the electric power system. The results obtained can be used when solving the problem of online assessing the effect of loads on the quality of electricity, since the initial data for this problem include the equivalent circuit parameters.

HIL real-time simulator based 3D-space vector pulse width modulation for performance analysis of 3-phase matrix converter

In this paper, Three Dimensional Space Vector Pulse Width Modulation (3D-SVPWM) is developed to obtain the performance analysis of a 3-phase matrix converter (MC). MC is used to convert 3-phase fixed AC voltage to 3-phase variable AC voltage, which provides superior performance compared to conventional AC to AC converters. The 9-bidirectional power switches in a 3-phase matrix converter are controlled by appropriate gating pulses utilizing 3D-SVPWM. In conventional AC to AC power converters, the common mode voltage is induced across the load terminal, which causes bearing failure and EMI issues and so leads to increased total harmonic distortion (THD). Implementing the 3D-SVPWM approach with the nearest switching state vector (NSV) selection mechanism alleviates these problems. In proposed system, CMV is reduced to 37 V, which is equivalent to a Vdc/8 time of the supplied AC input voltage and THD of 3-phase to 3-phase MC is reduced to 1.12% for output voltage and 2.18% for output current. The output findings of the simulation and real-time simulator are verified using the Matlab Simulink model and the HIL real-time (OPAL-RT) simulator.

Experimental Modelling of Point-Absorber Wave Energy Converter Arrays: A Comprehensive Review, Identification of Research Gaps and Design of the WECfarm Setup

Commercial wave energy exploitation will be realised by placing multiple wave energy converters (WECs) in an array configuration. A point-absorber WEC consists of a floating or submerged body to capture wave energy from different wave directions. This point-absorber WEC acts as an efficient wave absorber that is also an efficient wave generator. Optimising the WEC array layout to obtain constructive interference within the WEC array is theoretically beneficial, whereas for wind farms, it is only important to avoid destructive interference within an array of wind turbines due to wake effects. Moreover, the WEC array layout should be optimised simultaneously with the applied control strategy. This article provides a literature review on the state of the art in physical modelling of point-absorber WEC arrays and the identification of research gaps. To cover the scientific gap of experimental data necessary for the validation of recently developed (nonlinear) numerical models for WEC arrays, Ghent University has introduced the “WECfarm” project. The identified research gaps are translated into design requirements for the “WECfarm” WEC array setup and test matrix. This article presents the design of the “WECfarm” experimental setup, consisting of an array of five generic heaving point-absorber WECs. The WECs are equipped with a permanent magnet synchronous motor (PMSM), addressing the need for WEC array tests with an accurate and actively controllable power take-off (PTO). The WEC array control and data acquisition are realised with a Speedgoat Performance real-time target machine, offering the possibility to implement advanced WEC array control strategies in the MATLAB-Simulink model. Wave basin testing includes long- and short-crested waves and extreme wave conditions, representing real sea conditions. Within the “WECfarm” project, two experimental campaigns were performed at the Aalborg University wave basin: (a) a testing of the first WEC in April 2021 and (b) a testing of a two-WEC array in February 2022. An experimental campaign with a five-WEC array is under preparation at the moment of writing.

Dynamic Modeling of Alkaline Electrolyzer Based on Matlab Simulink Approach

Renewable energy as a backup energy source is becoming increasingly significant due to the world's environmental and ecological concerns. One of the most useful renewable energy methods used today is the production of hydrogen through electrolysis. When paired with solar-PV or wind energy, hydrogen produced by water electrolysis has the potential to play a key role as an energy carrier for future sustainable development. The inability to describe the internal operation of the process coupled with the flexibility issue is the main limitation of black box modelling. In this paper, an alkaline water electrolysis process was modelled dynamically. A stacked electrolyzer with each stack consisting of 21 series-connected steel cells and an electrolyte made of 30 wt% potassium hydroxide was employed. A dynamic thermal model for an advanced alkaline electrolyzer has been constructed based on basic thermodynamic and electrochemical reaction equations. The Matlab Simulink Model has this information. This approach provides more insight into the model dynamics and simulation based on the thermal and electrical approaches.

Application of machine learning for inter turn fault detection in pumping system

Pump fault diagnosis is essential for the maintenance and safety of the device as it is an important appliance used in various major sectors. Fault diagnosis at the proper time can reduce maintenance costs and save energy. This article uses a Simulink model based on mathematical equations to analyze the effects of parameter estimation of three-phase induction motor-based centrifugal pumps in inter-turn fault conditions. The inter-turn fault causes a massive in, a massive increase in current, which severely affects the parameters of both motor and pump. These have been analyzed by simulation through the Matlab Simulink model. Later, the results are verified by a hardware in loop (HIL) based simulator. In this paper, machine learning (ML) based artificial neural network (ANN) and ANFIS (ANN and Fuzzy) models have been applied for fault detection. ANN and ANFIS-based models provide a satisfactory level of accuracy. These models provide accurate training and testing results. Based on root mean square error (RMSE), R2, prediction accuracy, and mean validation value, these models are compared to find out which is more suitable for this experiment. Various supervised algorithms are compared with ANN, ANFIS, and lastly, found which is the most suitable for this experiment.

Hybrid Modulation for Reduced Switches AC-AC Multi Frequency Converter

This paper presents the Hybrid Modulation Technique for single phase AC-AC multi-Frequency converter to overcome the local square wave overshoot in out- put waveform which are responsible for harmonics content in converter and to get better smooth voltage waveform. And also, by using SPWM (Sinusoidal Pulse Width Modulation) and TPWM (Trapezoidal Pulse Width Modulation) a comparative analysis is done; it shows how converters behave with different modulation technique. The detail study of converter and modulation techniques are done here with including operation, block diagram and mathematical cal- culations. All the studies and experimental operation are performed by using MATLAB Simulink model simulation and the switch is used for converter is MOSFET