Control Methodology For Systems Research Articles

A study on the combination of crystallization-controllable phase change materials and solar-assisted heat pump for electricity demand shifting in space heating

Supercooled phase change materials offer a promising solution for space heating due to their ability to release latent heat upon crystallization initiation, even when stored at ambient temperatures. This unique property makes them ideal for solar-assisted space heating, where external activation enables on-demand heat release, addressing the critical need for energy-efficient heating solutions. In this study, a system promoting demand shifting is proposed, aiming to transfer energy consumption from morning and evening peak periods to daytime and high solar irradiance days, thereby enhancing the efficiency of solar heat pumps and reducing grid stress through the use of supercooled crystallization-controllable phase change materials. A model was developed, consisting of evacuated tube collectors, a buffer tank, heat storage tanks with crystallization-controllable phase change material, and a building heating demand model. The study introduces a novel system control methodology, focusing on an effective operation of tank shifting based on the heating requirement and solar energy availability. Real weather data were used to calculate system performance. With 50 m2 of collectors, a 1000-liter buffer tank, and a heat pump with a maximum output of 7 kW, the heat storage tanks are charged and discharged following the developed operational methodology. The system achieved a weekly coefficient of performance of 3.56 and successfully shifted electricity demand to solar hours, with only 28.5% of the total consumption occurring during domestic morning and evening peak times.

Development and demonstration of advanced predictive and prescriptive algorithms to control industrial installation

This paper explores the use of sophisticated, predictive AI algorithms for monitoring and optimizing industrial installations of CFB power plant. The effectiveness of the system was shown by applying it to a circulating fluidized bed (CFB 1300) power unit. A customized optimization algorithm was developed to manage the oxygen distribution within the combustion chamber. Implementing the developed control system methodology adjusted the fuel distribution, which in turn impacted the overall performance of the boiler. The approach was evaluated under different boiler operating scenarios, including simulated fuel line malfunctions. The devised methodology enables a reduction of approximately 17% in oxygen distribution imbalance within the combustion chamber when a failure was detected. Furthermore, the optimization algorithms facilitate a seamless adjustment in fuel loads, maintaining the necessary oxygen and temperature distribution at the control plane. Moreover, the capabilities of this system were demonstrated for the automatic identification of malfunctions within two crucial parts of the power unit. The initial issue pertains to a fault in the internal phase insulator of the block transformer, and the second occurrence involved the proactive identification of a membrane wall leak over 13 h before its failure.

Experimental performance of a modified Collins cycle cryocooler for in-space applications

This paper presents initial experimental results of a modified-Collins-cycle cryocooler designed for space cooling applications. A high efficiency and lightweight single-stage cryocooler design to provide 100 W of cooling at temperatures at 90 K is discussed. With multi-staging, cooling to 4 K is possible. A single-stage room-temperature floating piston-machine is experimentally demonstrated with helium as the working fluid. Cryocooler construction materials and control system methodologies are discussed.

Novel IEC 61850-based off-site engineering and validation methodology for protection, automation, and control systems

The IEC 61850 standard has driven the development of power systems Protection, Automation, and Control Systems (PACS) over the past years. Although it is well-known for its communication protocols, several concepts and features are underused. This paper presents a new engineering and validation methodology applying the IEC61850 standards concepts to optimize the project life cycle by standardizing and enhancing engineering and testing. An electrical specification has been defined according to the IEC 61850 data modeling, reducing misinterpretations at the specification and configuration stage. The proposed top-down configuration approach establishes a user’s profile and product naming to eliminate the vendor’s dependability. The validations were performed using modern commercial tools. The results show that the proposed methodology makes it possible to have a reliable engineering process where the output of the previous stage provides all required information is independent of the next one. The project naming approach makes it possible to validate the system integration based on the agnostic system specification files in an early project stage. Thus, the protection devices and supervision systems can be validated independently, reducing integration issues in the later stages without affecting interoperability and making it possible to achieve interchangeability.

Nonlinear Internal Control System in Business

The purpose of the written study is to study the relationship between the qualifications of the CFO and the nonlinear system of the firm’s internal control system. We used three indicators of the competence of the CFO: financial education, accounting, seniority, and education. Using the model of Kazakhstan companies registered on the stock exchange in 2023. In the methodology of the internal control system, in which stimuli cause a reverse response, the internal control system should be recognized as a nonlinear approach that can have a high impact if it has little impact. The results of this study show a negative relationship between the financial, accounting experience of a CFO and work experience under a nonlinear system of internal control, which indicates that firms with high-quality CFO are facing a nonlinear internal control system in business. A business management team with a large number of employees is associated with an effective internal control system. In addition, the political preferences of senior management directly and indirectly affect the quality of financial statements through the internal control system. Several reliability tests confirm our main results. The results show that a capable CFO can effectively implement a suitable subsystem. The results of the study of a nonlinear system of internal control in business, in terms of improving individual elements of internal control in companies, can be used by members of audit firms.

Simulation-Based Evaluation of Sliding Mode Control with Washout Filter for Power Balancing in Battery Energy Storage Systems

This research paper presents a simulation-based evaluation of a novel sliding mode control (SMC) approach with a washout filter for power balancing in battery energy storage systems (BESS). Unlike traditional proportional-plus integral control methods, the proposed SMC technique is specifically tailored for charging and discharging BESS units. The primary objective of this study is to investigate the efficacy of the proposed SMC-based scheme in achieving optimal power balancing at the DC bus of the BESS. A comparative analysis is conducted to assess the performance of the developed SMC strategy against the conventional proportional-plus integral controller. MATLAB simulations utilizing Simulink and the Sim Power System toolbox are employed to obtain comprehensive results. The findings of this study provide valuable insights into the effectiveness of the SMC with washout filter for enhancing power balancing in BESS applications, thereby contributing to advancements in energy storage system control methodologies. Keywords: Sliding Mode Control (SMC), Washout Filter, Power Balancing, Battery Energy Storage Systems (BESS), Simulation-based Evaluation, MATLAB Simulation

Model-based Security Countermeasure Designing Methodology for Industrial Control Systems based on Cyber Kill Chains and Defense-in-depth Models

Model-based Security Countermeasure Designing Methodology for Industrial Control Systems based on Cyber Kill Chains and Defense-in-depth Models

A General Design Methodology for Fractional Cascade Control Systems

A General Design Methodology for Fractional Cascade Control Systems

Enhancing the transient stability of interconnected power systems by designing an adaptive fuzzy-based fractional order PID controller

The reliable and efficient operation of the electrical energy transmission system heavily relies on maintaining stability as a key requirement. Interconnected power systems often experience low-frequency oscillations (LFOs), which have the potential to initiate instability and, subsequently, necessitate careful attention and investigation. To tackle this issue, researchers have focused on various controllers, including Fractional-Order Proportional-Integral-Derivative (FOPID) controllers. The FOPID controller, with its increased number of design parameters, has proven to be more successful than the traditional PID controller in various engineering applications. However, determining the optimal parameters for the controller becomes more challenging due to the increased design space. Moreover, the performance of fixed-gain FOPID controllers may be degraded when confronted with highly nonlinear and uncertain controlled objects such as power systems. This issue is primarily attributed to the static nature of fixed-gain FOPID controllers. To overcome these challenges associated with fixed-gain FOPID controllers and to instill an adaptive quality, this article introduces a novel power system control methodology. This adaptive approach combines a FOPID control strategy with a fuzzy logic system and is denoted as EOA-AFFOPID. The proposed adaptive controller dynamically tunes its coefficients through a fuzzy block, which significantly improves the overall performance of the control system. To establish a performance benchmark, we have also created an alternative controller, named EOA-FOPID, a version of the optima FOPID controller with fixed coefficients. The proposed methodology is applied to multi-machine interconnected power systems equipped with Static Synchronous Series Compensators (SSSCs), and comparative evaluations are conducted with other popular recent control strategies. The comparisons demonstrate the effectiveness of the EOA-AFFOPID control strategy in damping system fluctuations and achieving significant performance improvements in terms of different metrics including overshoot, undershoot, and settling time.

Methodology and Research of Intelligent New Energy Vehicle Motion Control System based on Fuzzy Adaptive

To resolve the difficult control issue of intelligent new energy automobile in the process of vehicle control, the study starts from the vehicle motion mode and splits the vehicle control into two parts, transverse control and longitudinal control. Among them, the longitudinal speed control is controlled by an improved adaptive PID model, while the lateral angle control is dominated by an indistinct adaptive PID model, afterwards longitudinal speed control is combined with the lateral angle control for joint control. Finally, the study uses the actual lane simulation to verify the three perspectives of transverse control, longitudinal control and joint control respectively. It shows that the longitudinal control and lateral control are well realized with the improved adaptive PID model control effect at 8km, 15km and 20km per hour. Meanwhile, maximum trajectory error of the combined direction and transverse dominate is always lower than 0.5m at vehicle speeds of 8km/h, 16km/h and 20km/h in the integrated road environment and the combined longitudinal speed and transverse angle control performance is good in the curves. This shows that the model designed by the research can realize adaptive real-time precision control.

Discrete‐time modelling methodology of networked control systems under packet delay and dropout

AbstractModels and control techniques for networked control systems (NCSs) can be divided into continuous‐time and discrete‐time types. Unlike the continuous‐time analysis, literature on discrete‐time analysis and control of NCSs under packet delay and dropout shows a variety of different models. However, a systematic study of these models is absent in the literature. This article is a methodology for these models. Different factors involved in making this variety are discussed. The models are described and it is shown how they are different or related to each other. The models are from the existing literature. However, to complete the methodology some of the models are introduced by the authors. Furthermore, the concept of sequence matrix is introduced which helps to differentiate some models and should be considered when NCS is analysed as a switched linear system. This methodology can be used as a basis for selecting the suitable model in analysis and design of NCSs. Denial of service (DoS) attack and time delay switch (TDS) attack can be considered as packet dropout and packet delay respectively. Thus, this methodology can also be used in analysis and design of NCS under these cyber‐physical attacks.

Fault Diagnosis Methodology of Redundant Closed-Loop Feedback Control Systems: Subsea Blowout Preventer System as a Case Study

In closed-loop feedback control systems, faults are propagated through the feedback link, which eventually leads to the abnormality of the entire system. Generally, it is very difficult to identify the faults of systems under the influence of the closed-loop feedback link. The existence of redundancy improves the reliability of the system. Meanwhile, it also poses new challenges to the fault diagnosis of multiple redundant systems. In this regard, a causality-based method is proposed for the fault diagnosis of closed-loop feedback control system with multiple modular redundancy. The dynamic Bayesian networks for fault diagnosis are established based on sensor data and system parameters. The networks consist of four layers, which are sensors, performances, monitors, and faults, respectively. Furthermore, the conditional probabilities of the fault nodes are calculated by Noisy-OR and Noisy-MAX models. The proposed method can dynamically evaluate system performance and integrate other monitoring information as evidence to assist faults diagnosis and location. A double modular redundant control system for a subsea blowout preventer is used as a case to demonstrate the proposed method, and the results show that the proposed method has high accuracy. The influence of sampling frequency, noise, and redundancy mode on diagnosis results is studied and discussed in the case study.

A Review of Power Co-Generation Technologies from Hybrid Offshore Wind and Wave Energy

Renewable energy resources such as offshore wind and wave energy are environmentally friendly and omnipresent. A hybrid offshore wind-wave energy system produces a more sustainable form of energy that is not only eco-friendly but also economical and efficient as compared to use of individual resources. The objective of this paper is to give a detailed review of co-generation technologies for hybrid offshore wind and wave energy. The proposed area of this review paper is based on the power conversions techniques, response coupling, control schemes for co-generation and complimentary generation, and colocation and integrated conversion systems. This paper aims to offer a systematic review to cover recent research and development of novel hybrid offshore wind-wave energy (HOWWE) systems. The current hybrid wind-wave energy structures lack efficiency due to their design and AC-DC-AC power conversion that need to be improved by applying an advanced control strategy. Thus, using different power conversion techniques and control system methodologies, the HOWWE structure can be improved and will be transferrable to the other hybrid models such as hybrid solar and wind energy. The state-of-the-art HOWWE systems are reviewed. Critical analysis of each method is performed to evaluate the best possible combination for development of a HOWWE system.

The Impact of Audit Culture and Internal Control Systems on Audit Quality: The Case of Lebanese Banks

The audit process is a representation of the engagement team's testing procedures. A company's culture and working procedures are two factors that might affect one's performance on the job. Leaders may message that they care about their and their audit firm's reputations by showing appreciation for high standards of audit quality and stressing the necessity of "doing the right thing" in the public interest. The Center for Audit Quality is only one part of the Audit Quality Disclosure Framework. There should be a clear emphasis on audit quality, and leaders should set the tone by doing so themselves. Only 300 employees from the businesses above participated in the research. Those 288 employees work for a wide variety of companies. This study’s findings shed light on the connection between strong internal controls and good governance in Lebanon’s banking sector. Senior management will focus on organizational compliance, the internal control system and monitoring methodologies, effective corporate governance, risk assessment, quality assurance, and independent forensic investigation since these are all prerequisites for an independent audit role. The chance of management undermining internal controls designed to identify and prevent fraud will decrease, and a more positive culture will result. Both managers will check that sufficient internal procedures are in place to safeguard corporate property.

Design of Non-Conventional Flight Control Systems for Bioinspired Micro Air Vehicles

This research focuses on the development of two bioinspired micro air vehicle (MAV) prototypes, based on morphing wings and wing grid wingtip devices. The morphing wings MAV tries to adapt the aerodynamics of the vehicle to each phase of flight by modifying the vehicle geometry, while the wing grid MAV aims to minimize the aerodynamic and weight penalty of these vehicles. This work focuses on the design methodology of the flight control system of these MAVs. A preliminary theoretical conceptual design was used to verify the requirements, wind tunnel tests were performed to determine aerodynamic characteristics, and suitable materials were selected. The hardware and software configuration designed for the control system, which fulfills the objective of adaptive and optimal control in the wingtip-based prototype of the wing grid, is described. Finally, the results of the flight control on the prototype MAVs are analyzed.

Cross-domain alert correlation methodology for industrial control systems

Alert correlation is a set of techniques that process alerts raised by intrusion detection systems to eliminate redundant alerts, reduce the number of false positives, and reconstruct attack scenarios. Since Industrial Control Systems (ICSs) exhibit both a physical and a cyber domain, they present unique challenges for alert correlation. The presence of heterogeneous domains each with its specific threats has led to the development of multi-domain detection techniques. Indeed, some detection approaches rely solely on observations at the level of the cyber domain, while other approaches will monitor the physical process. Although these two approaches are complementary, the nature of the information carried by the detection alerts differs. In this article, we develop an alert correlation framework tailored explicitly for ICSs. We combine physical domain intrusion detection alerts with more classical cyber domain intrusion detection alerts. We develop a correlation approach that maps physical domain alerts into the cyber domain using alert enrichment. We also propose a specific alert selection for correlation that adapts to the state of the physical process by dynamically adjusting the size of the selected alert window. We test our approach on a realistic experimental setup with and we publicly release all datasets used to derive our results. Our cross-domain correlation methodology achieves better correlation metrics compared to classical temporal-based correlation approaches in terms of false correlation rate, missing correlation rate and alert reduction.

Optimal sensor placement methodology of hydraulic control system for fault diagnosis

During the state monitoring and fault diagnosis of hydraulic control system, different kinds of sensors are used to collect fault signals. The arrangement of a limited number of sensors in the most reasonable positions of the hydraulic system, that is, to solve the problem on the optimal placement of sensors, is the key to improving efficiency of fault diagnosis. Aiming at fault diagnosis of hydraulic control system, this paper proposes a sensor placement methodology of hydraulic control system to determine the optimal number and position of sensors based on a discrete particle swarm algorithm. First, the model of fault propagation and sensor response time is evaluated by a simulation model. Second, a discrete optimization model for sensor placement is established. Finally, a discrete particle swarm optimization algorithm is used to calculate the optimal solution for the optimal placement of sensors. In the iterative process, a Monte Carlo simulation-based comparison algorithm is used for the evaluation and comparison of particle. The simulation case of typical multi-circuit hydraulic control systems proves that the proposed method has fast convergence speed and optimization results. A real case of a subsea blowout preventer control system shows that the proposed method reduces the number of sensors and data redundancy effectively. Compared with the traditional method, the robustness of the proposed system under the optimal solution is improved.

Health evaluation methodology of remote maintenance control system of natural gas pipeline based on ACWGAN-GP algorithm

The remote maintenance system of natural gas pipeline is of great significance to ensure the safe and stable operation of the pipeline network. The multi-classification method based on machine learning is more effective for the health evaluation of remote maintenance control system than the traditional evaluation method based on expert experience. In view of the sev ere imb alance i n the nu mber of s amples of f ive health levels, a health evaluation methodology of remote maintenance control system based on Wasserstein distance sand auxiliary classification generative adversarial network (ACWGAN-GP) is proposed. Firstly, the model stability is improved by introducing Wasserstein distance and gradient penalty. The generator generates balanced data, while the discriminator trains with generated and actual data. In this way, several ACWGAN-GP sub-models are trained. Then, the health levels of the sub-model are directly obtained by using the discriminator to classify the samples. Finally, according to the hierarchical relationship of the system, a parallel-serial combined evaluation method is adopted. By this means, the health evaluation model of remote maintenance control system including ACWGAN-GP sub-models is constructed. The experimental results based on 13 sets of KEEL and UCI multi-class imbalanced datasets and actual sampling data show that the effectiveness and advancement of the proposed method improved significantly compared with the existing similar typical algorithms.

Methodology of quality control system functioning for nanometry reference measures calibration

Methodology of quality control system functioning for nanometry reference measures calibration

A model-based design methodology for flight control systems: Global 7500 pitch control case study

This article introduces an original model-based design methodology addressing a high-performance aircraft design challenge: conflicting performance requirements. The case study of the Global 7500 elevator actuation system also provides in-depth insight into the complex design process of today’s fly-by-wire flight control systems. The methodology presented here redefines the aircraft manufacturer’s involvement in the design process of the systems, implementing analysis and iteration capabilities early in system development. To this end, it introduces a novel modeling approach for analyzing loaded rate requirements by simulating closed-loop performance with a generic nonlinear second-order state filter, including the main performance limitations without requiring a preliminary design definition. In this way, it provides means to mature the system requirements and addresses requirement conflicts upfront. Then, a simulation-based preliminary sizing and performance assessment validates the candidate design concept. It also secures the preliminary design phase by implementing advanced design uncertainties and involving interfacing systems and disciplines early in the process. The redefined methodology identified directly that the problem’s root cause was a conflict between stability and control and flutter protection requirements. It also indicated that the first sizing driver is the response time required under a specific failure case. These findings lead to an optimal elevator actuator design compliant with matured performance requirements. Thus, the methodology resolved a design challenge blocking the Global 7500 aircraft development and prevented redesign occurrences later during the detailed design phase. In this way, it directly contributed to the successful development of the Global 7500 and its optimal operational performance. This methodology applies to future aircraft design challenges, and the technical insight provides valuable lessons learned for high-performance T-tail business jets.