Programmable Logic Controller System Research Articles

EXPERIMENTAL RESEARCH OF LINE POWER UNLOADING AUTOMATICS WITH ITS TRIPPING CHARACTERISTICS CORRECTION

In conditions of complicated structure of modern power grids, a special emphasis is given to the issues of ECA failure-free operation. This article is concerned with the problems of increasing sensitivity and selectivity of line power unloading automatics because its correct operation plays an important role in ensuring energy security and survivability of power systems.
 
 Within the framework of this paper, the full cycle of development of ECA algorithm is considered. ECA is performing the functions of line power unloading automatics. The development cycle includes the tasks of tentative assessment of electrical equipment operating modes, rationale for choosing the automatics tripping characteristics, algorithm design and programmable logic controller (PLC) based implementations. It also includes the laboratory testing with the use of real-time hardware and software complex.
 
 The calculation data of steady-state and transient operating modes of power electrical equipment presented in the article were carried out in software complexes RastrWin, Rustab. The power facilities of the interconnected power systems of Urals, Siberia and Kazakhstan were considered as modeled objects of power systems. In accordance with the obtained results, the tripping characteristics of device being developed were determined.
 
 Based on the results of mathematical simulation of electrical equipment transient operating modes, the major disadvantages of device algorithm, which controls the active-power flow through the line, were determined. Besides, methods focused on increasing the sensitivity and selectivity of such automatics are proposed.
 
 The developed algorithm controls the active-power flow over a given cross section. Measurements of electrical parameters are carried out at one of the lines in cross section. The total value of active-power flow over the cross section is calculated according to the equivalent circuit. To increase the sensitivity and selectivity of automatics, the algorithm uses the action time adjustment. It is determined depending on the previous operating mode of transmission line.
 
 The algorithm for line power unloading automatics described in this article was implemented on a PLC system in accordance with the IEC 61131 standard. The obtained device was successfully tested on the real-time hardware and software complex. This paper presents the results of the carried out device performance tests, and the characteristics of the used mathematical simulation.

Multi-agent collaborative control parameter prediction for intelligent precision loading

Due to the low adjustment accuracy of manual prediction, conventional programmable logic controller systems can easily lead to inaccurate and unpredictable load problems. The existing multi-agent systems based on various deep learning models has weak ability for advanced multi-parameter prediction while mainly focusing on the underlying communication consensus. To solve this problem, we propose a hybrid model based on a temporal convolutional network with the feature crossover method and light gradient boosting decision trees (called TCN-LightGBDT). First, we select the initial dataset according to the loading parameters' tolerance range and supply supplementing method for the deviated data. Second, we use the temporal convolutional network to extract the hidden data features in virtual loading areas. Further, a two-dimensional feature matrix is reconstructed through the feature crossover method. Third, we combine these features with basic historical features as the input of the light gradient boosting decision trees to predict the adjustment values of different combinations. Finaly, we compare the proposed model with other related deep learning models, and the experimental results show that our model can accurately predict parameter values.

Solar and wind energy in Poland as power sources for electrolysis process - A review of studies and experimental methodology

The production of hydrogen is still a major challenge, due to the high costs and often also environmental burdens it generates. It is possible to produce hydrogen in emission-free way: e.g. using a process of electrolysis powered by renewable energy. The paper presents the concept of a research, experimental stand for the storage of renewable energy in the form of hydrogen chemical energy with the measurement methodology. The research involves the use of proton exchange membrane electrolysis technology, which is characterized by high efficiency and flexibility of energy extraction for the process of electrolysis from renewable sources. The system consist of PV panel, PEM electrolyzer, battery, programmable logic controller system and optional a wind turbine. Preliminary experimental tests results have shown that the electrolyzer can produce in average 158.1 cc/min of hydrogen with the average efficiency 69.87%.

A refinement development approach for enhancing the safety of PLC programs with Event-B

Programmable Logic Controllers (PLC) are widely used in Industrial Control Systems (ICS) with strict safety assurance requirements. Unfortunately, traditional techniques for debugging prefer to use post-development approaches, such as simulation and black-box testing, rather than enhancing safety before programing. In this paper, we propose a refinement-based approach to model and verify PLC systems, aiming to assure safety properties by construction. It uses the Event-B formalism and focuses on the levels of requirement analysis, specification refinement, and system development. This approach takes a three-layer framework stepwise to specify the behaviors and properties of PLC programs, thereby reducing the modeling complexity. The basic firmware layer models the general mechanisms of PLC firmware, such as periodical instruction execution and centralized I/O scanning, which are application-independent models with fundamental safety properties at an abstract level. The middle layer establishes configuration models. These models correspond to the PLC settings and interactive environments of a specific system, such as I/O addresses and peripheral devices. The business layer models business logic with more specific system-level safety requirements. With our approach, the safety properties of PLC systems can be verified throughout the modeling and refinement process. In addition, rules are proposed to convert the most concrete Event-B model into PLC code satisfying the IEC 61131-3 standard. We demonstrate this approach with a real-world running example of a pump control system for gas transmission. • A refinement-based approach for modeling PLC systems using Event-B. • Defining PLC features are modeled with a 3-layer framework. • It decomposes the complexity of modeling and verification by stepwise refinement. • The safety requirements of PLC systems can be verified during the development. • It generates PLC program code compatible with IEC 61131-3 standard from the model.

An effective intrusion-resilient mechanism for programmable logic controllers against data tampering attacks

Programmable Logic Controllers (PLCs) play a prominent role in critical infrastructures, such as power grid, transportation, and petrochemical industry. Suffering from data tampering attacks, PLCs are fragile as the forged data could cause significant damage to industrial machines and human safety. However, less attention has been paid to develop resilience mechanisms for automatically recovering PLCs systems from anomalous states under malicious attacks. In this work, we present the first resilience approach for protecting PLCs against data tampering attacks. The key observation we leverage is that the programmable characteristic of a PLC enables a defender to ensure its data integrity by embedding security mechanism into its control logic. In particular, we design a novel data authentication mechanism to generate and authenticate the message digest of the communication data between PLCs. An anomaly alert will be triggered if the data authentication fails. The execution on received malicious commands is disabled to avoid detrimental effect and keep the system stable. Furthermore, to recover real data from malicious modifications, a data sender is required to encrypt data using the proposed RC5-based data recovery algorithm and re-transmit it. The data authentication and recovery approaches can be implemented on the programmable logic circuit of PLCs through code updating, which requires no alterations to its current hardware architecture. We present the prototype of our resilience scheme and conduct real-world experiments to validate its efficacy under 12 typical attack scenarios. Our results show that our approach achieves 97.4% of accuracy in data authentication and 98.1% of success rate in abnormal state recovery. Finally, we assess the practicality of the proposed mechanism in terms of execution delay.

Wire laser metal deposition of 22% Cr duplex stainless steel: as-deposited and heat-treated microstructure and mechanical properties

Duplex stainless steel (DSS) blocks with dimensions of 150 × 70x30 mm3 were fabricated by Laser Metal Deposition with Wire (LMDw). Implementation of a programmable logic control system and the hot-wire technology provided a stable and consistent process producing high-quality and virtually defect-free deposits. Microstructure and mechanical properties were studied for as-deposited (AD) material and when heat-treated (HT) for 1 h at 1100 °C. The AD microstructure was inhomogeneous with highly ferritic areas with nitrides and austenitic regions with fine secondary austenite occurring in a periodic manner. Heat treatment produced a homogenized microstructure, free from nitrides and fine secondary austenite, with balanced ferrite and austenite fractions. Although some nitrogen was lost during LMDw, heat treatment or reheating by subsequent passes in AD allowed the formation of about 50% austenite. Mechanical properties fulfilled common requirements on strength and toughness in both as-deposited and heat-treated conditions achieving the highest strength in AD condition and best toughness and ductility in HT condition. Epitaxial ferrite growth, giving elongated grains along the build direction, resulted in somewhat higher toughness in both AD and HT conditions when cracks propagated perpendicular to the build direction. It was concluded that high-quality components can be produced by LMDw and that deposits can be used in either AD or HT conditions. The findings of this research provide valuable input for the fabrication of high-performance DSS AM components.Graphical

Robots for Pharmaceutical Production: A Benchtop Robotic Automation Approach for Manufacturing Prefilled Syringes

Automation and robotics have become a staple in the biological manufacturing sector due to their ability to efficiently work without operator input. Industrial robotic arms present themselves as a valuable tool for biological manufacturing because of their ease of programming and flexibility. This paper represents the use of a benchtop robot and automation system capable of manufacturing in-syringe liquid drugs. An International Organization for Standardization (ISO) compliant robotic arm (Stäubli TX2-60), customized end-effector, syringe venting system, and Cartesian gantry platform were prototyped and integrated to create an automated solution for manufacturing cyclic olefin copolymer (COC) polymer syringes. A Siemens programmable logic controller (PLC) system is developed to interface with the robot and the Cartesian gantry platform. Automated filling of a tray of 50ml syringes is proven to be feasible. The process of stoppering a COC syringe using a customized venting tube is demonstrated. An automated gantry system is also demonstrated as a proof of concept for a complete manufacturing system.

Sistem Tertanam Berbasis PLC pada Simulator Pemberian Label dan Pemisahan Botol

Utilization of photoelectric and fiberoptic sensors equipped with a number of actuators have been integrated into an embedded system based on a programmable logic controller (PLC). The labeling mechanism is based on the detection of the photoelectric sensor due to the photoelectric effect, while the bottle separation process is based on the detection of the fiberoptic sensor for two different colors. The objectives of this research includes three things, namely (i) produce a simulator controlled by a PLC system with assisted the help of sensors and actuators, (ii) create a ladder-based program structure, and (iii) measure the performance of the embedded system based on the performance of sensors and actuators. The research methods are conducted based on the research objectives through three stages, namely (i) the assembly of the conveyor frame, installation of the entire device, and integrated wiring; (ii) providing a 64-bit CX-Programmer, determining algorithms, compiling ladder, and compiling and uploading the entire program structure; and (iii) synchronization conditions and readings of on-board sensors for activation of all devices in the output line, and measurement of the processing time of stamping and bottle separation assisted by a pneumatic system. The results of the system performance during the labeling process for green and red bottles were fifteen times each, as was the case with the bottle separation process for green and red bottles, fifteen times each. The performance of the system is based on the success rate during the labeling process of 100%, while the success rate during the bottle separation process is 73.33%. The unsuccessful separation of bottles by 26.67% occurred in green bottles. The general conclusion is that a fabricated embedded system can be used as a simulator for a mechanical system of labeling and separating bottles based on bottle color.

Interactive Water Level Control System Simulator Based on OMRON CX-Programmer and CX-Designer

Abstract— Programmable Logic Controller (PLC) is an essential component in industrial automation where it acts as the backbone of the system. In line with Industrial Revolution (IR) 4.0, most industrial and manufacturing sectors move towards automation systems. Preparing university students about automation and PLC fundamental knowledge and skill is crucial before graduation, where the preoccupied knowledge will enhance graduate employability. Fulfilling this task, universities have to prepare the necessary equipment in the laboratory for teaching and learning purposes. The problem arises when certain universities with budget constraints cannot purchase the equipment for the PLC embedded system as huge costs have to be borne by universities. Thus, an alternative approach has to be taken where the main objective of this paper is to develop an interactive water level control system simulator as a substitution of the expensive automation PLC embedded system for teaching and learning purposes. OMRON software, namely CX-Programmer and CX-Designer used to design and develop an interactive water level control system simulator. In addition, the interactive water level control will be embedded with a PLC component that replicates the actual automation system laboratory equipment. Moreover, universities with a limited budget can utilize the tool for teaching and learning purposes of the PLC and automation system, which is the main contribution of this paper. Keywords—Water Level Control System, Programmable Logic Controller, Simulator, CX-Programmer, CX-Designer.

Simulator Proses Pengisian dan Pemasangan Tutup Botol Terkendali PLC Berbantuan Miniatur Konveyor

A miniature conveyor machine assisted by embedded systems and controlled by a programmable logic controller (PLC) has been fabricated with the operating mechanism is based on the detection of two different colors. The objectives of this research are to obtain a miniature machine is controlled by the PLC system, create a ladder diagram-based program structure, and measure the performance of the embedded system. Obtaining the machine is carried out through assembly of the conveyor frame, installation of all devices, and integrated wiring. The programming for the Omron PLC system is based on providing the CX-Programmer 64 bits, establishing algorithms and compiling ladder diagrams, and compiling and uploading processes. The performance measurement includes synchronization conditions between the simulator and the control system, observations of the readings of installed sensors for activating all devices on the output side, and observing the measurement of the filling process time and the installation of bottle caps assisted by the pneumatic system. The results of the performance during the process of filling and installing the lid obtained a success rate of 75%, based on four trials, three successes, and one failure. The general conclusion is that the embedded system that has been built can be used as a simulator for the mechanism of filling liquid into bottles and installing bottle caps, and it is as an implementation of instrumentation and automation processes.

A 20 K cryogen-free leak detection system for cryogenic valves by using a GM cryocooler

Sealing performance under cryogenic temperatures should be a consideration in the development of a cryogenic valve for use in cryogenic engineering. In the present work, a cryogen-free leak detection system at 20 K to conduct leakage testing of cryogenic valves was developed. The experimental system was composed of a cooling system, a leak detection system, and a PLC (Programmable Logic Controller) system. Compared with the traditional cryogenic leak detection systems, this system using the GM cryocooler instead of cryogen is beneficial for the application for its low operating cost, simple structure, and safe handling. Five valves can be installed simultaneously and tested in sequence. The helium mass spectrometer leak detector is used for its sensitive response and high precision. The reliability of this system was verified by testing the leak rate of the system itself. Three high-pressure cryogenic solenoid valves were tested using helium gas under the pressure varied from approximately 2.5 bar to 80 bar and at both room temperature (300 K) and liquid hydrogen temperature (20 K). The tested valves can be cooled from room temperature to 18 K within 6 h. The test results of the internal leakage rate and the external leakage rate of the samples were discussed. This system will aid in the inspection of many critical cryogenic components such as liquid oxygen and liquid hydrogen valve assemblies for which leakage may lead to serious consequences.

Development of IoT Based Smart Irrigation System with Programmable Logic Controller

Smart irrigation system is an automatic irrigation and monitoring system on agricultural land with a sensor, automation, and control technology based on the Internet of Things (IoT). This system can reduce the agricultural activities that were previously performed manually into an automatic system with a reduced human supervision. Smart Irrigation systems that are widely developed used Arduino as the controller. Arduino still lacks in response, low durability, and sensitivity to temperature change, hence requiring frequent maintenance to avoid weather disturbances, insects, and others. This paper presents a development of a smart irrigation system using a Programmable Logic Controller (PLC) as the controller and a soil moisture sensor as a humidity condition measurement tool. The advantage of using PLC as a controller is more stable and has sensor compatibility with higher accuracy. Hence the results are more consistent and accurate. The PLC system is expandable, allowing for the inclusion of more channels for sensors and other measurement instruments. The developed system can collect data on soil moisture conditions, trigger valves, and perform auto irrigation using sprinklers, reducing or even eliminating the need for human intervention. The IoT collects data from sensors and updates the data into a database system, allowing users to monitor the land conditions in real-time. The developed system was predicted to save manpower (20%) and water usage (42.47%) compared to the conventional method. Keywords : Smart Irrigation; IoT; PLC; Moisture Sensor; Sprinkler

Trends in solar power plant automation technologies

As solar power continues to grow, plant automation and control becomes more important. It comprises all the necessary intelligence to turn the solar energy into a reliable and flexible power source. As leading automation provider, field proven PLC (Programmable Logic Controllers) and SCADA (Supervisory Control and Data Acquisition) system accompanied by dedicated control and diagnostics functions assure reliable power production and grid code compliance at all times.

Modelling and Simulation of SCADA and PLC System for Power System Protection Laboratory

Abstract The protection of power system is an essential trait in a huge network to efficiently detect and isolate the sections undergoing faults or abnormal behaviour. The key components of a protection scheme include circuit breakers, relays, switchgears and fuses which employ communication from one station to another to achieve high-speed tripping. The automation of these components at the laboratory level using programmable logic controller (PLC) along with supervisory control and data acquisition (SCADA) system owns paramount importance for intelligent decision making, sensing, actuating, monitoring and maintaining the record in the host server. This paper discusses such a technique for conventional power system protection laboratory at a new level of development to promote a control system through PLC and SCADA. The control system has indication of over and under values of voltage, load and frequency, which can trigger malfunctioning of equipment and must be rectified. Furthermore, ground fault and inverse current indication are added to the system for monitoring and controlling purposes. The proposed system enhances the efficiency and safety of the expensive equipment and the personnel to the next level and also introduces new standards of automated protection schemes for modern technical institutes.

Anomaly Detection Based on Temporal Behavior Monitoring in Programmable Logic Controllers

As Programmable Logic Controllers (PLCs) are increasingly connected and integrated into the industrial Internet of things, cybersecurity threats to PLCs are also increasing. Adversaries can perform a denial of service (DoS) attack based on the transmission of a large number of network packets, and a control-logic injection attack through sophisticated packet transmission. We propose an approach to detecting and defending against attacks that exploit security vulnerabilities in a PLC system. In order to protect against indiscriminate packet transmission attacks that exploit uncontrolled resource consumption vulnerabilities, an abnormal temporal behavior detection method is proposed that monitors the CPU usage of tasks. If a temporal anomaly is detected, the proposed approach tries to detect control-flow anomalies by examining the sequences of function calls, then detects stack-based buffer overflow attacks. The proposed method is implemented in a water tank control system for evaluation purposes. The experimental results show that the proposed method can improve the security of the system by detecting anomalies in temporal behavior with little system overhead.

CAN Controller Design for Diagnosing Automation System Failure

This paper proposes a controller area network (CAN) controller design for monitoring the state of a programmable logic controller (PLC) system and predicting its failure. The PLC system is the main device used in production automation equipment based on a large amount of sensor data. The proposed controller collects and stores the status data of multiple PLCs and sensors, and sends the collected data to the host system through the CAN interface. Then, the host system analyzes the transmitted data and predicts whether the PLC system will fail. Moreover, the host system informs the user of the risk of system failure. The proposed controller is composed of a processor block and CAN communication module. It was tested by connecting a PLC device. Consequently, a diagnostic message was received per a period of 500 ms.

The combination effect of preozonation and CNTs layer modification on low-pressure membrane fouling control in treating NOM and EfOM

In this study, the combination effect of preozonation and carbon nanotubes (CNTs) layer modification on low-pressure membrane (LPM) fouling control was systematically investigated. To understand the alleviation mechanism of the hybrid process, natural organic matter (NOM) from IHSS and effluent organic matter (EfOM) from actual sewage effluent were both selected as the typical organic foulants presented in actual surface water and wastewater. A dead-end continuous flow model combined with programmable logic control system was used to operate four membrane filtration units and their backwash processes. With a constant permeates flux, the fouling resistant of CNT modified LPM after preozonation could be evaluated according to the increase in transmembrane pressure (TMP). The results revealed that the hybrid approach of preozonation and CNTs modification could significantly improve the anti-fouling ability of LPM, reduce the backwash frequency, and improve the reversibility of membrane fouling. During the filtration of EfOM and NOM, preozonation improved the water treatment capacity of the CNTs modified membranes. The experiment of mass balance revealed that preozonation enhanced the recoverability of CNTs modified membrane and greatly increased its operation time in treating EfOM and NOM. The molecular weight distribution as well as EEM analysis demonstrated the dissimilar characteristics of EfOM and NOM, which caused the different treatment efficiency by preozonation and CNT modification. The mechanism of EfOM/NOM fouling on LPM was summarized as the primary blocking by medium-MW EfOM/NOM. CNTs modification had a better effect on the control of LPM fouling when treating EfOM, as it removed the medium-MW EfOM by adsorption and prevented the pores blockage of the original PVDF membrane. Preozonation had a better effect on the control of LPM fouling when treating NOM, as it greatly changed the MWD of NOM by removing medium-MW NOM. The combination effect of the hybrid preozonation and CNTs modification resulted in the most effective fouling control of LPM by both decreasing the medium-MW and large-MW EfOM/NOM. At the same time, it decreased irreversible fouling related with membrane pore blocking. The hybrid approach demonstrated its promising application for LPM fouling control in actual sewage water and surface water treatment process.

Simulator Berbasis PLC untuk Pengaturan Lalu-lintas Jalan Raya pada Perlintasan Jalur Kapal

A PLC based simulator has been assembled for controlling road traffic at ship line crossings. The objectives of this study include (i) assembling a miniature bridge body, a lift-drop back mechanism for highway traffic at ship crossings, and an operating system based on a programmable logic controller (PLC) and (ii) measuring the performance of the operating system through its presence input-output signal. Assembly with the following stages: (i) implementation of miniature bridge construction; (ii) selection and placement of sensors; (iii) installation of pumps for hydraulic systems; (iv) installation of servo motor assisted latches; (v) installation of traffic control lights and indicators; and (vi) manufacture of operation panels, wiring, and installation of PLC systems. Mitsubishi PLC system programming is based on compiling algorithms and ladder diagrams with GX Works-2 32 bit. Performance measurement includes (i) when synchronization between the operating system and control on the PLC in the form of input from the operation panel and sensors on the input line are processed in the PLC program to produce an output in the form of appropriate and precise control, (ii) when the sensors installed in the system operation has functioned as programmed into the PLC, and (iii) during the process of lifting and lowering the miniature of the bridge body, there is a time difference of 26 seconds with the condition that the lifting time is longer than the time of lowering the miniature bridge body. The general conclusion is that the miniature of the bridge body and the operating system that has been built can be used as a simulator for the existence of a bridge that can be lifted and lowered again as a highway traffic lane at a ship crossing.

A model-based machine learning to develop a PLC control system for Rumaila degassing stations

Degassing station breakdowns can be dangerous to the operator health and the environment. Programmable logic controllers (PLCs) are key modules of manufacturing control systems that are applied in the complex oil and gas units to reduce manpower and unnecessary faults. However, feeding a PLC with data is a difficult part due to the need of system log files which records all events that occur in the oil fields and provide visibility to a given environment. Moreover, most critical chemical processing plants and oil distributions are visualized and inspected by Supervisory Control and Data Acquisition Systems (SCADA). These systems have been focused on safety, and there are issues that they could be the target of worldwide terrorists. Along with the frequently rising internet-related attacks, there is indication that our degassing stations may similarly be susceptible; for that reason, it is essential to secure PLC and SCADA from undesired incidents. Recently, machine learning (ML) has been increasing interest in industrial systems to detect, identify, and store information. Therefore, we propose to apply an advance ML based on deep neural networks to the PLC system with the purpose of: 1) detecting anomalous or irregular PLC actions; 2) Optimizing the operation of systems and its facilities; 3) allowing the equipment to respond to changing and novel scenarios; 4) Making predictive maintenance possible. The SIMATIC S7-1214 CPU universal TIA platform was used as the main decision-making module. Experimental results demonstrate the effectiveness and utility of the proposed approach to process large amounts of data analytics and sensor measurements, allows it to spot potential problems and provide possible solutions.

Rancang-Bangun Prototipe Sistem Kontrol Berbasis Programmable Logic Controller untuk Pengoperasian Miniatur Penyortiran Material

A miniature sorting of material quality has been made, aided by a prototype of the controller system based on the Mitsubishi FX1N-24MR Programmable Logic Controller (PLC). A number of stages include the manufacture of the conveyor system unit, the electrical system, PLC programming, and performance measurement. The conveyor unit assembling was processed by installing the conveyor belt, dc motor, pneumatic cylinder, solenoid valve, and sensors. The electrical system is an integration of the Mitsubishi FX1N-24MR PLC, switched-mode power supply, miniature circuit breaker (MCB), dc voltage regulator circuit, relays, digital counters, pushbuttons, and selector switches arranged in a 20 x 30 x 15 cm panel box. Mitsubishi PLC system programming is based on algorithmic determination and ladder diagram arrangement assisted by GX Developer (GX Work). Performance measurement in the form of pulse readings is carried out by setting and manufacturing ladder counters and shift registers to count the number of pulses for each material and the accuracy of sorting when the material is detected simultaneously. The system performance is indicated by pulse reading accuracy and sorting timing accuracy. The reading of the pulse from the proximity switch affects the counter calculation to activate the pneumatic cylinder unit in sorting. Sorting for material-A takes 11 pulses, while for material-B, it takes 19 pulses. The synchronization measurement functions when an error occurs in the system in order to maintain the input received is the same as the output in the PLC-based control system.