The growing interest with the developments of renewable sources owing to less environmental pollution creates challenges for the grid operators. Virtual Power Plant (VPP) is a novel concept that will ...integrate the small distributed energy resources and will act as a single conventional power plant in the electricity market. As a core energy management system in VPP, the energy should be dispatched optimally for achieving the maximum profit. Therefore, smart energy management is developed in this article of VPP with Programmable Logic Controller (PLC) and Internet of Things (IoT) in a unified market environment that integrates the DA and RT market. The cost characteristics for the interruptible load, battery storage system are modelled individually. The PLC and IoT based automation is proposed for optimal dispatch strategy of VPP. The proposed scheme can efficiently handle the energy demand for the VPP domain. Four different scenarios are considered with different loading conditions for validation of the concept of smart energy management. The profitability for each scenario is shown with the experimental results.
Designs of timer function blocks (FBs) are presented in the article. The developed modules are IEC 61131-3. An analysis of IEC 61131-3 in terms of timer functionality and implementation options is ...presented. Three types are presented, timer-on, timer-off, and timer-pulse, with each type designed to be fully hardware or software-like. Both designs, hardware or software-like, can operate as multi-channel timers. Particularly noteworthy is the software-like design, for which a solution without edge detectors was achieved. Such a feature was obtained by reversing the method of time determination by counting the difference between the start and end times and by using specific features of the D flip-flops, that is, clock-enable inputs. The presented timers were written in Verilog language and implemented in an FPGA chip. Thanks to the universal design of the interface, the proposed FBs can be used for the hardware support of existing programmable logic controllers (PLCs) or as an integral part of newly built PLC CPUs. The idea of a CPU architecture with hardware support is proposed. The paper presents the results of the implementation in an FPGA of the Kintex UltraScale+ family from AMD-Xilinx.
In this paper, Internet of Things (IoT) and artificial intelligence (AI) are employed to solve the issue of energy consumption in a case study of an education laboratory. IoT enables deployment of AI ...approaches to establish smart systems and manage the sensor signals between different equipment based on smart decisions. As a result, this paper introduces the design and investigation of an experimental building management system (BMS)-based IoT approach to monitor status of sensors and control operation of loads to reduce energy consumption. The proposed BMS is built on integration between a programmable logic controller (PLC), a Node MCU ESP8266, and an Arduino Mega 2560 to perform the roles of transferring and processing data as well as decision-making. The system employs a variety of sensors, including a DHT11 sensor, an IR sensor, a smoke sensor, and an ultrasonic sensor. The collected IoT data from temperature sensors are used to build an artificial neural network (ANN) model to forecast the temperature inside the laboratory. The proposed IoT platform is created by the ThingSpeak platform, the Bylink dashboard, and a mobile application. The experimental results show that the experimental BMS can monitor the sensor data and publish the data on different IoT platforms. In addition, the results demonstrate that operation of the air-conditioning, lighting, firefighting, and ventilation systems could be optimally monitored and managed for a smart system with an architectural design. Furthermore, the results prove that the ANN model can perform a distinct temperature forecasting process based on IoT data.
Open platform communications (OPC) unified architecture (UA) is a communication standard increasingly used in industrial automation systems to enable the exchanging of control and management data ...between distributed entities. This paper proposes the design of an OPC-UA agent to enable UA information service and client functionalities in legacy programmable logic controllers (PLCs). The agent runs on a separate machine connected to the PLC using a dedicated link and maintains shared memory for certain variables in the PLC. Based on the periodically synchronized variables, the agent services the OPC-UA information model and executes client function blocks on behalf of the PLC. One important design feature is the remote procedure call of IEC 61131-3-based function blocks using synchronized variables. This allows the standard OPC-UA client functions to be used in existing PLCs which only support numeric types and do not support strings or complex structures. To validate the proposed design, we implement an agent prototype and demonstrate the successful monitoring and control of an industrial robot controller via OPC-UA. Through experiments, we evaluate the performance of UA functions in terms of the latency of read services for an increasing number of items. The evaluation results are believed to provide useful insights into agent-based approaches for integrating legacy PLCs into the OPC-UA framework.
Energy Conservation or ENERCON is the main concern of every industry today. With the advent of new
technology installed in the process line, the need to address the conservation of applied energy ...such as steam, water,
electricity, and compressed air are still the core to run an industrial plant. The use of compressed air as a blower is widely
used now a day for several benefit compared to running the blowing system with the motor. The system presented in this
study is used to automatically switch off the compressed air that serves as a can top blower before printing whenever there
are no can detected in the conveyors in a pineapple cannery industry. The cutting off of the compressed air used will result
in significant saving in the plant-wide drive on conserving energy. The hardware composition, control system design,
software application and simulation of the Programmable Logic Controller (PLC) and Human Machine Interface (HMI) -
based monitoring and control system of compressed air are present in this work. The system’s main components are PLC,
HMI, Inductive sensors and Directional valves. This paper focuses on the application for a pineapple manufacturing plant
but not limited to the compressed air application but for all the industrial utilities mention above.
This paper presents some of the issues related to the implementation of advanced control structures (PI controller with additional feedback, Model Predictive Controller) for drives with elastic ...coupling on a programmable logic controller (PLC). The predominant solutions to electric drive control include the use of rapid prototyping cards, signal processors or programmable matrices. Originally, PLC controllers were used to automate sequential processes, but for several years now, a trend related to their implementation for advanced control objects can be observed. This is mainly due to their compact design, immunity to disturbances and standard programming languages. The following chapters of the paper present the mathematical model of the drive and describe the implementation of the proposed control structures. A PI controller with additional feedback loops and a predictive controller are taken into consideration. Their impact on the CPU load was analysed, and the work was summarised by a comprehensive experimental study. The presented results confirm that it is possible to implement advanced control structures on a PLC controller for drives with elastic coupling while maintaining a sufficiently low load on its CPU.
•Timed process calculi for expressing both genuine and malicious activities within a PLC.•Runtime enforcement based on Ligatti et al.’s edit automata.•Algorithms to synthesise edit automata from PLC ...specifications.•Simulation and bisimulation proof techniques.•Simulations of a significant use case in Simulink/Matlab.
We define a simple process calculus, based on Hennessy and Regan's Timed Process Language, for specifying networks of communicating programmable logic controllers (PLCs) enriched with monitors enforcing specification compliance at runtime. We define a synthesis algorithm that given an uncorrupted PLC returns a monitor that enforces the correctness of the PLC, even when injected with malware that may forge/drop actuator commands and inter-controller communications. Then, we strengthen the capabilities of our monitors by allowing the insertion of actions to mitigate malware activities. This gives us deadlock-freedom monitoring: malware may not drag monitored controllers into deadlock states. Our enforcing monitors represent a formal mechanism for prompt detection of malicious activities within PLCs. Finally, we illustrate our results by implementing in Simulink a non-trivial Water Transmission Network (WTN) system, and testing the effectiveness of our monitors in detecting and mitigating three different attacks targeting the PLCs of our WTN.
Water quality is essential for a healthy life, so it is necessary to look for technologies to measure its parameters in real time and automatically. The purpose of this study was to implement and ...determine the reliability of an automated system to evaluate the Organoleptic Water Quality intended for human consumption, in the urban distribution network of the district of Daniel Hernandez - Peru, using a Programmable Logic Controller (PLC) and Simulink. The study was carried out from January to March 2024, corresponding to the rainfall season. In the process of the research, a data acquisition and processing algorithm was implemented in a Simatic S7 1500 PLC with analog input module; using the National Sanitation Foundation Water Quality Index (NSF-WQI) methodology. The work focused on five key water parameters: potential hydrogen (pH), electrical conductivity (EC), turbidity, free chlorine (FCL) and temperature. The methodology included programming in contact language (KOP) of the algorithm for calculating subscripts for each parameter, according to the functions established by NSF-WQI. Measurements were performed with 4-wire sensing devices with 4-20 mA current signals, ensuring data accuracy. The interface to visualize the parameters and the water quality index was implemented in Simulink, communicating via OPC UA with the PLC server, facilitating the graphical representation of the Organoleptic Water Quality index. The overall equipment efficiency (OEE) or automated system implemented was 90.56%, indicating its acceptable reliability for evaluating water quality. By performing the measurements, with the sensors of the five parameters immersed in tap water, at each of the three established sampling points (Dwelling_1, Dwelling_2 and Dwelling_3) along the water distribution network, the system facilitated the automated and real-time evaluation of the quality, resulting in an average NSF-WQI of 83.08%, classifying the water as good for human consumption. This information is important for water quality management and can guide future treatments to achieve better quality.
We propose a novel methodology for real-time monitoring of software running on embedded processors in cyber-physical systems (CPS). The approach uses real-time monitoring of hardware performance ...counters (HPC) and applies to multi-threaded and interrupt-driven processes typical in programmable logic controller (PLC) implementation of real-time controllers. The methodology uses a black-box approach to profile the target process using HPCs. The time series of HPC measurements over a time window under known-good operating conditions is used to train a machine learning classifier. At run-time, this trained classifier classifies the time series of HPC measurements as baseline (i.e., probabilistically corresponding to a model learned from the training data) or anomalous. The baseline versus anomalous labels over successive time windows offer robustness against the stochastic variability of code execution on the embedded processor and detect code modifications. We demonstrate effectiveness of the approach on an embedded PLC in a hardware-in-the-loop (HITL) testbed emulating a benchmark industrial process. In addition, to illustrate the scalability of the approach, we also apply the methodology to a second PLC platform running a representative embedded control process.
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