Simulation Model Of System Research Articles

A New Pabs Model for Quantitatively Diagnosing Phosphorus Nutritional Status in Corn Plants

Accurate diagnosis of plant phosphorus nutritional status is critical for optimizing agricultural practices and enhancing resource efficiency. Existing methods are limited to qualitatively assessing plant phosphorus nutritional status and cannot quantitatively estimate the plant’s phosphorus requirements. Moreover, these methods are time-consuming, making them impractical for large-scale application. In this study, we developed an advanced phosphorus absorption model (Pabs) that integrates the phosphorus nutrition index (PNI) and phosphorus use efficiency (PUE). The PUE, a critical metric for assessing phosphate fertilizer use efficiency, was quantified by comparing yields under fertilized and unfertilized conditions. Utilizing the Agricultural Production Systems Simulator (APSIM) model, we simulated maize (Zea mays L.) phosphorus concentration (P) and aboveground biomass (Bio) under varying phosphorus application rates. The model exhibited robust performance, achieving an R2 above 0.95 and an RMSE below 0.22. Based on the APSIM model simulations, a phosphorus dilution curve (Pc = 3.17 Bio−0.29, R2 = 0.98) was established, reflecting the dilution trends of phosphorus across growth stages. Furthermore, the use of vegetation indices (VIS) to evaluate phosphorus nutritional status also showed promising results, with inversion accuracies exceeding 0.70. To validate the model, field sampling was conducted in maize-growing regions of Changchun. Results demonstrated a correct diagnosis rate of 75%, underscoring the model’s capacity to accurately estimate phosphorus requirements on a regional scale. These findings highlight the Pabs model as a reliable tool for precision phosphorus management, offering significant potential to optimize fertilization strategies and support sustainable agricultural systems.

Construction, verification and engineering application of bleed air system simulation model based on MOC8 test engineering simulator

Construction, verification and engineering application of bleed air system simulation model based on MOC8 test engineering simulator

Temporal Evolution of Environmental Impact Arising from Municipal Solid Waste Treatment Systems: A Case Study of Guangzhou, China

It is important to assess the temporal evolution of environmental impacts arising from municipal solid waste (MSW) under different policies, especially in China. However, most previous research has primarily focused on the effects of policies at the system management level, neglecting their influence on technical-level implementation, which compromises the accuracy of policy effect simulations. This study developed a comprehensive simulation model that integrates a life cycle assessment (LCA) and a dynamic simulation model of a complex system to enhance the accuracy of environmental impact simulations of the MSW management system in Guangzhou. The model considers how different measures affect changes in the physical composition of MSW at the technical level and their subsequent impact on MSW generation at the system level. The study employed five scenarios to simulate the impacts of different strategies on MSW generation levels and environmental consequences of MSW treatment systems, encompassing the entire process of generation, collection, and disposal. LCA results simulate a 24.14% reduction in the unit environmental impact of incineration technology due to MSW classification, which alters the material composition, decreases water content, and enhances the caloric value. The comprehensive simulation model’s results illustrate that implementing measures such as MSW charging, economic control, and population control can effectively reduce overall MSW by 31.35%. In terms of environmental impact, Guangzhou reached its peak in 2018 but experienced a subsequent decline due to the continuous implementation of MSW classification policies. Among the various strategies considered, the scenario focusing on technological improvement exhibited the most significant reduction in overall environmental impact by enhancing power generation efficiency and minimizing pollution emissions, followed by metering and charging policies utilizing economic levers. Finally, recommendations on the coupling effect of policies, greenhouse gas emission reduction, and incineration residue recycling are proposed. The comprehensive simulation model can provide scientific theoretical support to build a sustainable MSW treatment system for Guangzhou and other cities worldwide.

Enhancing line loadability in urban rail systems: evaluating the impact of distributed generation on voltage stability, power losses and generation costs

Alternative source of electrical energy for urban railway electrification system is Direct Current (DC). Traction Power Substations (TPS) were essentially connected to the electrical grid network managed by the electrical utility company for operating and powering purposes. Power unbalance frequently occurs in the high voltage railway network due to the load of the traction system. The aim of this project is to find the impact of distribution generation (DG) for line loadability in urban rail systems. The output that needs to be considered are the voltage profile, power losses and generation cost. The simulation was considered to prove the positive impact of distributed generation for line loadability in urban rail system. Electrical energy was crucial for Direct Current (DC) railway electrification systems, as it provided the traction power necessary for train operations via Traction Power Substations (TPS) that connected to the electrical grid network. However, power imbalances frequently arose due to the varying loads imposed by traction systems, resulting in inefficiencies, suboptimal voltage profiles, increased power losses and higher operational costs. With the expansion of urban rail networks and the growing need for efficient power management, it became vital to explore solutions that could enhance loadability and system performance. This project examined the impact of integrating Distributed Generation (DG) on the line loadability of urban rail systems, concentrating on improvements in voltage profiles, reductions in power losses and the evaluation of generation costs. The methodology involved developing a detailed simulation model of the urban rail system, incorporating DG scenarios, analyzing their effects on voltage stability, power losses and costs. The simulation results were anticipated to demonstrate that DG could improve voltage stability, reduce power losses, lower generation costs and increase line loadability. The implications of these findings encompassed enhanced operational efficiency, potential economic benefits despite high initial investments, increased sustainability through renewable energy and valuable guidance for future infrastructure development and investment decisions.

SIMULATION MODEL OF THE FUNCTIONING OF THE LOGISTICS SYSTEM FOR THE SUPPLY OF GRAIN CARGOES FROM UKRAINE TO THE COUNTRIES OF THE WORLD

The article analyses the existing developments in the logistics of grain and similar cargoes in international systems. Due to the increase in logistics costs, Ukrainian agricultural companies receive a lower price compared to world market prices - they have to bear the costs caused by an inefficient logistics system. Therefore, it is necessary to develop a simulation model of the logistics system for the supply of grain cargo from the producer to the seaport of departure, as the main hub of communication with ports around the world. And the modelling will allow us to determine the level of influence of the obtained data on the transport material flow on the efficiency of decision-making. It is proposed to build models based on Petri nets, which allow to study the behaviour of an object in real time by assessing the performance of the system without forecast data. Today, the logistics system of grain cargo delivery in Ukraine has a structure based on the interaction of participants: agricultural companies as producers and organisers of grain exports, farmers, transport and logistics companies, as well as the existing infrastructure of Ukrainian and foreign ports, railways, and roads. This principle of interaction allowed us to build a structural model of functional interaction in the grain supply system. Based on this interaction and the principles of organising the supply of grain cargoes from production (harvesting) to the port of departure, a two-tier model of the functioning of this logistics system was developed. At the top are models of data collection and processing by an agricultural company, and at the bottom is a simulation model of the logistics system. A simulation model of grain cargo movement from the sender to the seaport of departure based on Petri nets has been built, which reflects the structure of relationships between the elements of the system and the dynamics of changes in its states in a compact form. On the basis of the built model, a simulation was carried out for three variants of distribution of cargo flow by two modes of transport. It has been determined that the option of uniform distribution of grain cargo between road and rail transport allows to save time.

MODELLING AND EXERGETIC TECHNO-ECONOMIC ANALYSIS OF A SYSTEM FOR HYDROGEN PRODUCTION FROM EMPTY BANANA FRUIT BUNCH

One of the most effective and reliable methods for generating hydrogen fuel using biomass is the gasification method. However, utilization of different biomass feedstock has the ability to withstand production of syngas which can be utilized for several applications. The study investigated the feasibility of hydrogen from Empty Banana Fruit Bunch (EBFB) biomass and the energetic techno-economic analyses of biomass gasification plant with a developed system simulation model aspen plus simulator V11. Five chemical reactions were used in production process and were simulated in ASPEN Plus simulator through biomass gasification method which aimed in removing C, CO, CO2, CH4, and H2O to convert them into hydrogen gas. However, the total exergy out divided by the total exergy in gives exergy efficiency. Hence, total exergy out subtracted from total exergy in depicts exergy destruction. The exego-economic method utilized in the exergo-economic analyses is the Specific Cost method (SPECO). The results affirmed that 80.465 kg/hr of H2 can be produced from 2000 kg/hr of empty banana fruit bunch at every 39.92 k.mol/hr mole flow of EBFB. However, at a temperature below 900 0C CO decreases, CO2 increases. Above 1000 0C, CO increases hence decreases CO2 emission. The system total exergy in, total exergy out, percentage exergy efficiency, and exergy destruction are 4534.77 kJ/kg, 3857.295 kJ/kg, 0.8506 %, and 677.475 kJ/kg. Hence, system exergy stream cost rate, component-related cost rate, component-related cost difference, and component exergoeconomic factor are 407527.644$/h 1555.57$/h, 0.5679%, and 0.9089% respectively. Further studies may concentrate on how to reduce CO through regulated temperature and pressure differences so as to increase the quantity of hydrogen production.

Research on Self-Recovery Ignition Protection Circuit for High-Voltage Power Supply System Based on Improved Gray Wolf Algorithm

In order to solve the problems of traditional high-voltage power supply ignition protection circuits, such as non-essential start–stop power supply, a slow response speed, the system needing to be restarted manually, and so on, a high-voltage power supply system self-recovery ignition protection circuit was designed using an IGWO (improved grey wolf optimization) and PID control strategy designed to speed up the response speed, and improve the reliability and stability of the system. In high-voltage power supply operation, the firing discharge phenomenon occurs. Current transformers fire signal into a current signal through the firing voltage value and Zener diode voltage comparison to set the safety threshold; when the threshold is exceeded, the fire protection mechanism is activated, reducing the power supply voltage output to protect the high-voltage power supply system. When the ignition signal disappears, based on the IGWO-PID control of the ignition self-recovery circuit according to the feedback voltage, the DC supply voltage of the high-voltage power supply is adjusted, inhibiting the ignition discharge and, according to the ignition signal, “segmented” to restore the output of the initial voltage. MATLAB/Simulink was used to establish a system simulation model and physical platform test. The results show that the protection effect of the designed scheme is an improvement, in line with the needs of practical work.

The Structural Design and Analysis of the Multi Nozzle Relay Air-Jet Inserting System by Profile Reed Guiding for 3D Weaving Machine

Introduction: Based on the literature, this article designs a parameterized simulation model of a multi-layer jet weft insertion system by profiles reed guidance for a 3D loom on the PTC Creo9.0 platform, including the main supersonic nozzle, supersonic auxiliary nozzle (relay nozzle), and multi-slot profiles reed components. Method: Based on the existing basic theory, experimental results, and empirical data of turbulent jet, the parameters of the multi-layer jet weft insertion system, as well as the structural parameters and the relative positions of the main, auxiliary nozzle and profile reed components, such as the center distance of each layer's main nozzle, auxiliary nozzle spacing, auxiliary nozzle installation angle, spray direction angle, and spray angle, have been determined preliminarily. Result: Further, the basic flow field parameters, such as the supply pressure of the main and auxiliary nozzles and the shape of multi-layer profile reeds, have been determined optimally on the Virtual Prototype Collaborative Simulation Platform (PTC Creo9.0/ANSYS Workbench/Fluent 2024R1), and the rationality of the structural design also been verified; on the premise of ensuring that the airflow velocity of each layer's profiles groove meets the requirements of weft insertion, the design and simulation calculation is repeatedly modified, and the optimal structural design parameters of the multi-layer weft insertion system and nozzle is finally determined. Conclusion: To explore the feasibility of multi-layer jet weft insertion, the design of threedimensional multi-layer jet weft insertion looms has laid a theoretical foundation, laying a good foundation for the emergence and industrial manufacturing of three-dimensional multi-layer jet weft insertion looms, and providing an important reference for the innovative design of threedimensional multi-layer water jet weft insertion looms.

Design and Analysis of a Direct Current–Based Ice Melting System for an Overhead Contact System in Electrified Railways

In recent years, extremely low-temperature weather conditions have resulted in the formation of ice on the contact network of electrified railways, significantly affecting the security of these systems. To address the issue of icing on the overhead contact system, this paper proposes a direct current–based ice melting system. This paper outlines the topological structure of the contact network ice melting system and examines its operational principles. A finite element model was established to investigate the characteristics of the ice melting process on the contact line, and a quantitative analysis was conducted to assess the impact of four critical variables: temperature, ice thickness, direct current, and conductor configuration. Ultimately, a simulation model of the contact line ice melting system for the traction power supply system was developed, and the output/input characteristics of the ice melting system were analyzed to validate its feasibility.

Application of the non-circular sprocket in the timing chain drive system

As a fundamental component of hybrid vehicles, the timing chain drive system significantly improves fuel economy while minimizing transmission error. A non-circular sprocket is used in a timing chain drive system to improve the dynamics characteristics of the system. In the scheme to reduce the crankshaft speed fluctuation, the relationship between the transmission ratio and the camshaft rotation angle is determined by analyzing simulation and experimental results. The mathematical relationship between the transmission ratio and the pitch curve of the non-circular sprocket is deduced. The pitch curve and phase angle of the non-circular sprocket are calculated. Combined with the self-constructed dynamics model of the hydraulic tensioner, a complete three-dimensional timing chain drive system simulation model is established based on the recursive algorithm and Hertz contact theory. The non-circular sprocket is installed into the system at the initial mounting angle. Dynamics simulations are carried out taking into account actual operating conditions. The simulation results prove that the use of a non-circular crankshaft sprocket can effectively reduce speed fluctuation of the camshaft sprocket, transmission error, and maximum chain tension when the crankshaft speed fluctuates regularly. This research proposes and validates a method to improve the dynamics characteristics of the system.

A Two-Stage Optimisation Approach for a Sustainable Physical Internet Multi-Modal Barge–Road Hub Terminal

The logistics and transportation sectors are struggling to manage empty containers (ECs), resulting in unused resources, inefficiencies, and increased CO2 emissions. The Physical Internet (PI) concept provides an opportunity to improve container sharing and transportation by intelligently organising logistics resources. This paper shows how PI principles can address the EC problem in truck transportation. The objective is to reduce CO2 emissions with improved space-sharing strategies. The problem is formulated and solved using a two-stage optimisation approach (2Stage-Opt) to optimise container motion. The validity of the 2Stage-Opt solutions is tested using a developed multi-agent system simulation (MASS) model to replicate the behaviour of real multi-modal hubs. This approach is evaluated using a real-world case study from a multi-modal logistics centre in the north of France. The results indicate that utilising PI-container solutions offers significant sustainability benefits, especially in reducing the number of trucks used in the simulation and the CO2 emissions from ECs.

Coordinated control strategy for improving frequency security of LCC[sbnd]HVDC sending-end system with large-scale wind power

To improve the frequency security of the LCCHVDC sending-end system with high penetration of wind power system and achieve optimal utilization of frequency regulation resources, a cooperative control strategy involving wind power and LCCHVDC in frequency regulation is proposed. Firstly, under a variety of scenarios, the power support requirements of LCCHVDC sending-end system are analyzed according to the power regulation margin of various frequency regulation resources and the disturbance power, and a multi-time scale frequency regulation control strategy for DFIG based wind farms is proposed, which combines the advantages of variable speed control and variable pitch angel control. And a cooperative control strategy of DFIG and LCCHVDC considering the frequency regulation deadband is proposed. Then, based on the maximum power regulation margin of synchronous generators and wind farms, the key control parameters of relative control links are designed to enable them autonomously adjust the active power according to various scenarios to involve in inertia response and primary frequency regulation task. Finally, the effectiveness of the control strategy is verified by the simulation model of LCCHVDC sending-end system with large-scale wind power, which significantly improves the frequency security and stability.

Hybrid Control Strategy for LLC Converter Based on Improved Fruit Fly Optimization Algorithm

This paper presents a hybrid control strategy for the LLC resonant converter in X-ray machines, addressing the limitations of voltage gain range under Pulse Frequency Modulation (PFM) and dynamic response under Phase Shift Modulation (PSM). The strategy employs an improved fruit fly optimization algorithm (IFOA) to optimize PI control and integrate Hybrid Phase-Shifted and Frequency-Modulated control. It dynamically adjusts the switching frequency and phase shift angle to maintain output stability and efficiency, ensuring optimal operation under rated conditions. A Matlab-based system simulation model confirmed the stability and accuracy of the IFOA in controlling the converter. Subsequent prototype testing validated the strategy’s effectiveness in reducing conduction losses, enhancing overall efficiency, and demonstrating practical feasibility and superiority.

Stochastic optimization to maximize water supply index in conjunctive use of surface and groundwater

Systematic operation of water resources systems requires rules that consider the uncertainties affecting system performance. Here, stochastic dynamic programming (SDP) is used to structure and solve a full-scale surface and groundwater conjunctive use model to derive a multiparameter operational policy (rule) that maximizes the water supply index (WSI). The model uses a Markovian representation of inflows to account for hydrologic uncertainties. Both the reliability of allocated water and its vulnerability are employed to define the WSI. To overcome the computational burden inherent with SDP, infeasible solutions are identified and removed from the model solution process. Optimal expected values of WSI and surface and groundwater uses are assessed. The system simulation model with embedded rules is executed to assess the performance of the derived rules. The derived rules employ water rationing and account for long-term benefits during periods when the available surface and groundwater resources may suffice to meet demand. The simulation results demonstrate that the derived operational rules produce high WSI values for the long-term operation of the system and ensure sustainable groundwater use.

Dynamic Response Control Strategy for Parallel Hybrid Ships Based on PMP-HMPC

With increasingly stringent emission regulations, various clean fuel engines, electric propulsion systems, and renewable energy sources have been demonstratively applied in marine power systems. The development of control strategies that can effectively and efficiently coordinate the operation of multiple energy sources has become a key research focus. This study uses a modular modeling method to establish a system simulation model for a parallel hybrid ship with a natural gas engine (NGE) as the prime mover, and designs an energy management control strategy that can run in real time. The strategy is based on Pontryagin’s minimum principle (PMP) for power allocation, and is supplemented by a hybrid model predictive control (HMPC) method for speed-tracking control of the power system. Finally, the designed strategy is evaluated. Through simulation and hardware-in-the-loop (HIL) experimental validation, results compared with the Rule-based strategy indicate that under the given conditions, the SOC final value deviation from the initial value is reduced from 11.5% (in the reference strategy) to 0.39%. The system speed error integral is significantly lower at 39.06, compared to 2264.67 in the reference strategy. While gas consumption increased slightly by 2.4%, emissions were reduced by 3.2%.

Adaptive Multi-Function Radar Temporal Behavior Analysis

The performance of radar mode recognition has been significantly enhanced by the various architectures of deep learning networks. However, these approaches often rely on supervised learning and are susceptible to overfitting on the same dataset. As a transitional phase towards Cognitive Multi-Functional Radar (CMFR), Adaptive Multi-Function Radar (AMFR) possesses the capability to emit identical waveform signals across different working modes and states for task completion, with dynamically adjustable waveform parameters that adapt based on scene information. From a reconnaissance perspective, the valid signals received exhibit sparsity and localization in the time series. To address this challenge, we have redefined the reconnaissance-focused research priorities for radar systems to emphasize behavior analysis instead of pattern recognition. Based on our initial comprehensive digital system simulation model of a radar, we conducted reconnaissance and analysis from the perspective of the reconnaissance side, integrating both radar and reconnaissance aspects into environmental simulations to analyze radar behavior under realistic scenarios. Within the system, waveform parameters on the radar side vary according to unified rules, while resource management and task scheduling switch based on operational mechanisms. The target in the reconnaissance side maneuvers following authentic behavioral patterns while adjusting the electromagnetic space complexity in the environmental aspect as required. The simulation results indicate that temporal annotations in signal flow data play a crucial role in behavioral analysis from a reconnaissance perspective. This provides valuable insights for future radar behavior analysis incorporating temporal correlations and sequential dependencies.

Adaptive Weighted Particle Swarm Optimization for Controlling Multiple Switched Reluctance Motors with Enhanced Deviatoric Coupling Control

Switched reluctance motors (SRMs) are widely used in industrial applications due to their advantages. Multi-motor synchronous control systems are crucial in modern industry, as their control strategies significantly impact synchronization performance. Traditional deviation coupling control structures face limitations during the startup phase, leading to excessive tracking errors and exacerbated by uneven load distribution, resulting in desynchronized motor acceleration and increased speed synchronization errors. This study proposes a modified deviation coupling control method based on an adaptive weighted particle swarm optimization (PSO) algorithm to enhance multi-motor synchronization performance. Traditional deviation coupling control applies equal reference torque inputs to each motor’s current loop, failing to address uneven load distribution and causing inconsistent accelerations. To resolve this, a gain equation based on speed deviation is introduced, incorporating self-tracking error and gain coefficients for dynamic synchronization error compensation. The gain coefficients are optimized using the adaptive weighted PSO algorithm to improve system adaptability. A simulation model of a synchronization control system for three SRMs was developed in the Matlab/Simulink R2023b environment. This model compares the synchronization performance of traditional deviation coupling, Fuzzy-PID improved structure, and adaptive PSO improved structure during motor startup, sudden speed increases, and load disturbances. The validated deviation coupling control structure achieved the initial set speed in approximately 0.236 s, demonstrating faster convergence and a 6.35% reduction in settling time. In both the motor startup and sudden speed increase phases, the two optimized methods outperformed the traditional structure in dynamic performance and synchronization accuracy, with the adaptive PSO structure improving synchronization accuracy by 54% and 37.17% over the Fuzzy-PID structure, respectively. Therefore, the PSO-optimized control system demonstrates faster convergence, improved stability, and enhanced synchronization performance.

Interference Characteristics of Electromagnetic Transient Overvoltage on Secondary Equipment of UHV Fixed Series Capacitors

This manuscript addresses the issue of electromagnetic radiation interference experienced by secondary equipment in ultra-high voltage (UHV) fixed series capacitors (FSCs) under electromagnetic transient overvoltage conditions, which cannot be easily determined. To tackle this, a simulation and analysis method for the electromagnetic interference characteristics of secondary equipment is proposed. First, a primary system simulation model of UHV FSC is established, including modeling the platform’s multi-conductor system. The electromagnetic transient overvoltage signals between the low-voltage busbar and the high-potential platform are then simulated and analyzed under two conditions: spark gap triggering and disconnector operation. Next, a finite element model of secondary equipment is created to simulate and analyze the electric field distribution of different materials in the area of the measuring box. The shielding effectiveness of the measuring box is calculated using the overvoltage signals at the measuring box location as excitation. This method allows for the simulation of the electric field distribution in the measuring box area for different materials and calculates the shielding efficiency of the measuring box. It effectively simulates the complex electromagnetic environment of secondary equipment, assesses the electromagnetic shielding efficiency of the measuring box, and provides a theoretical basis for analyzing and improving the anti-interference characteristics of the measuring box.

Design of single-phase shifted full-bridge inverter voltage regulation system based on voltage-controlled closed-loop control and LLC resonant network

Abstract The phase-shifted full-bridge inverter is widely used in the field of power electronics technology, aiming to achieve precise regulation of the output voltage and improve the stability and efficiency of the power system. This paper proposes a single-phase phase-shift full-bridge inverter voltage regulation system and its parameter design method based on the LLC resonant network. Combined with voltage-controlled closed-loop control and APFC technology, the working mode of the system circuit is analyzed, and the system parameters are designed. The system simulation model is built in MATLAB/Simulink. The constant voltage output of the system is realized, the power factor is greater than 96%, and the relative error of the output voltage change is less than 2%.

Design of a two-stage photovoltaic grid-connected system with dual closed-loop control

Abstract This paper designs a two-stage photovoltaic grid-connected system with dual closed-loop control, cascading the topological structures of photovoltaic cells, boost chopper circuits, and inverter circuits. The front-stage boost chopper circuit control utilizes the incremental conductance method to achieve maximum power point tracking control. The rear-stage inverter circuit employs a dual closed-loop control system with an outer voltage loop and an inner current loop, incorporating a proportional-integral controller, to ensure stable DC-side voltage and unity power factor for grid connection. A simulation model of the two-stage photovoltaic grid-connected system designed in this paper was constructed and analyzed through simulation runs. The firmness of the DC-side voltage and the achievement of unity power factor during grid connection confirmed the operability and resultiveness of the cascaded topology and the control method.