Relay Research Articles

Under-voltage Protection of Power Transmission Lines

The continuous monitoring of the protection relay of the transmission line is desirable to ensure the system disturbance such as fault inception is detected in the transmission line. Therefore, the fault on the transmission line needs to be detected, classified, and located accurately to maintain the stability of the system. This paper presents design enhancement and development under voltage relay in power system protection using MATLAB/Simulink. The contacts of the under-voltage relay operate when voltage drops below a set voltage. It is used for protection against voltage drops to detect the short circuit. This work is carried out for all types of faults which only related to one of the parallel transmission lines. In overall operation conditions, the sample data were generated for the system by varying the different fault types and fault locations. This design system proposes the use of the MATLAB/Simulink-based method for fault classification and location of various types of faults.

Relay-Switching-Based Fixed-Time Tracking Controller for Nonholonomic State-Constrained Systems: Design and Experiment

Dear Editor, This paper investigates the fixed-time trajectory tracking controller design for nonholonomic chained systems with static state constraints. Firstly, a fixed-time tracking control law is given to carry out relay switching, which divides the controller development process into two stages. For the goal of designing fixed-time tracking controller in the second stage and avoiding the explosion of complexity, fixed-time filters are introduced. Under these preparations, a fixed-time tracking controller is elaborated by applying barrier-Lyapunov-function-based backstepping. In addition, a new tracking controller is also proposed to guarantee that the tracking error system is bounded before switching. It has been proved that the resulting closed-loop tracking error system states converge to a small neighborhood around zero within a fixed time and output states are kept in the predefined constrained regions.

Performance Analysis and Optimization for Coordinated Direct and Relay Covert Transmission With Multiantenna Warder

Covert communication is crucial to ensure the safety of wireless communications in Internet of Things (IoT) systems. In this paper, a multi-antenna relay is employed to enhance the communication link and avoid the transmission being detected by the multi-antenna warder simultaneously. Considering the dynamic fluctuating fading channels of IoT systems, a novel adaptive coordinated direct and relay transmission (ACDRT) scheme is proposed where the relay switches on/off adaptively to maximize the achievable covert rate. The covertness constraint requirements are derived with instantaneous and statistical warder-related channel state information based on the availability of the channel information in practical systems. Since both the direct and the relay links impact the system performance, the optimization problem is formulated, where the beamforming vectors are coupled. A semidefinite relaxation based line search method is proposed to address this problem. Besides, the globally optimal solutions can be obtained by the proposed method, which is rigorously proved mathematically. In addition, the conditions for achieving a positive covert rate are analyzed with the multi-antenna warder. Simulations demonstrate that the performance of the ACDRT is robust to covertness requirements when the positive rate condition holds, and significant covert rate gains can be obtained by the ACDRT with the multi-antenna relay compared with the conventional systems.

A novel sinusoidal design for an electrocoagulation reactor followed by an electro-Fenton reaction and a porous ceramic filter for the treatment of polluted waters.

In this research work, a novel design of an electro-Fenton reactor for the treatment of polluted water was investigated. In addition to the reactor with iron electrodes, a ceramic filter was also used. An electrical circuit was designed to change the cathodes and anodes every 24 s via an electrical relay between the electrodes. The untreated water was sucked into the reactor with an air pump and entered the electrocoagulation chamber after filtration with a ceramic filter. Then, it flows to the polyethylene filter to separate the coagulated particles from the fresh water. To produce 12 L of clean water, the system consumed 100 W of energy. Analysis of a river sample showed a reduction in nephelometric turbidity units (NTUs), total suspended solids (TSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Turbidity reduction studies have shown that the system can improve water transparency by 95%, thereby improving water quality to acceptable levels. Further, this system reduced TSS by more than 86%. In addition, BOD was reduced by more than 84% and COD by more than 88%, as shown by the change in the ratio of BOD to COD from 0.44 to 0.625, indicating improved water quality. According to the results, the treatment system can clean polluted waters, particularly during floods and when industries discharge their effluents into rivers.

Optimalisasi Labview Sebagai Kendali dan Monitoring Arus Tegangan pada Modul Solar Cell Menggunakan Jaringan Lokal

Renewable energy sources in Indonesia have been widely used, one of which is solar energy, for various needs, one of which is for solar power generation by using solar cells as the medium. In generating electricity, solar cells are very dependent on the intensity of the sun so as to produce currents and voltages that are not constant. Because of this, a monitoring system was created to monitor the current and voltage in a solar cell module to determine current and voltage conditions. In this study, the monitoring system used wireless data transmission via the XBee S2C module installed on the Arduino Mega 2560 and Arduino UNO. The INA 219 sensor is mounted on a solar cell module along with a relay module connected to the Arduino Mega 2560 and the XBee S2C module. The test results show that wireless data transmission cannot be used indoors at a distance of more than 20 meters. The INA 219 sensor as a reader for DC current and voltage parameters has an error rate of 0.49% to 0.75% for voltage and for DC current readings it has an error rate of 1.85%. The results of current and voltage readings are displayed on a LabVIEW interface in real-time and can be accessed via a web browser using a local network. Relay control carried out through LabVIEW has a delay time of 6.08 seconds. Logging data can be stored in .xls files and data displayed on a web browser has a delay of one to two seconds.

Design, Implementation, and Evaluation of an Automated Liquid Dispensing Machine

The metering of industrial manufacturing liquids is constantly being updated. Using an automated system, metered dispense can now be more accurate to its theoretical value. This system can help reduce the difference between theoretical and metered volumes in manufacturing applications. This paper describes an automated liquid dispensing machine that uses an AT Mega 328 microcontroller to control the metered volume to the programme set point. The machine's design and implementation include hardware systems assembled from various modules with various functions, such as a microcomputer, power supply, liquid level detection, liquid discharge, conveyor and container detection, and LCD modules. The data collected by the liquid level detection module is analyzed when the system is started to determine the liquid level in the tank. A user loads empty containers onto the conveyor, which are then transferred to the discharge point. The machine calculates the equivalent time in seconds to open the discharge solenoid valve via its control relay and dispenses the desired volume based on the user set point. The experiment performed on the machine with water as the test liquid revealed that the automated dispensing machine's maximum time permissible is 35 s, which corresponds to an equivalent volume of approximately 700 mL of water. Experiments were conducted to compare the theoretical time required to obtain a specified volume to the time required for the machine to dispense the same volume. The results showed that the machine's accuracy is approximately 97.87 %. Therefore, the machine can be used in beverage manufacturing companies, pharmaceutical industries, and laboratories to dispense and fill specified fluids that meet the machine's specifications.

System application strategy of the PowerFactory software environment for professional training under the electrical energy educational program

The paper analyzes the scope of application of the PowerFactory software complex in our country and abroad. The need to integrate the program into the educational process of higher technical institutions of Ukraine was determined. A strategy for the systematic application of the PowerFactory program for the professional training of future specialists in the power industry has been formulated. General recommendations on the integration of the program into the three-level system of training under the educational program “Electroenergetics” have been developed. In particular, based on the results of studies of the first bachelor’s level of higher education, basic knowledge and skills should be formed in the calculation of stable and transient modes, short-circuit currents and stability of power systems, starting electric motors, indicators of the quality of electric energy, network protection, including with the help of a program. This will allow to fully ensure the conceptual and analytical level of assimilation of knowledge. The second master’s level of training should involve mastering the skills of solving atypical professional tasks in the design of electric power facilities and relay protection and automation systems, optimization of modes, dispatch control and prospective development of the network in the PowerFactory environment. This will contribute to the productive and synthetic level of assimilation of the educational material. Mastering the DigSilent – DPL programming language and program interfaces should be a mandatory component of the training of PhD candidates. All this will allow in the future to solve complex problems within the scope of their dissertation research, which may be related to the planning and introduction of the energy system regime, improving the quality of electric energy, coordinating the operation of relay protection systems, automation and power electronics, optimizing the operation of distributed generation sources, ensuring reliability and stability of energy systems, etc.

ДОСЛІДЖЕННЯ ЦИФРОВИХ ТЕРМІНАЛІВ ЗАХИСТУ

Abstract. Due to the development of technologies, the widely used electromechanical relays in the electric power industry have been replaced by multifunctional digital relay protection terminals. For the training of students and electrical personnel of enterprises, new approaches to the creation of experimental stands are needed, which will allow us to study the features of the use of digital protection and fully reveal their capabilities. The purpose of the work is to improve the quality of the knowledge and practical skills received by students in working with digital protection blocks. To achieve the goal, a specialized laboratory stand for testing digital security terminals has been developed. The stand consists of a mathematical model of the protected object and hardware, due to which the model mode parameters are converted into physical signals and fed in real time to a real digital device. The study of the protected element is provided in the characteristic modes of its operation close to real ones by providing a connection between the relay protection terminal and the information model. The equipment used at the stand does not require significant capital investments, and therefore this approach is available to most design and training organizations. Keywords: digital protection terminal, experimental stand, analog-to-digital converter; digital-to-analog converter, mathematical model, induction motor.

Prototype of Automatic Transfer Switch (ATS) for Solar Power Plant Based on Arduino Uno

Electrical energy plays an important role in supporting daily human activities. The need for electrical energy always increases according to population growth. However, the supply of electrical energy is not proportional to population growth. To meet the demand for electrical energy, it is necessary to develop and use alternative energy such as solar energy. In this paper, the prototype of Automatic Transfer Switch (ATS) for PLN and solar power plant (SPP) is carried out so that the supply of electrical energy to the load can be distributed continuously. ATS is electromechanical equipment that operates automatically to move the source of electrical energy from the main grid (PLN) network to SPP when the PLN network occur a faults or blackout. ATS will restore the source of electrical energy from PLN automatically when the supply of electrical energy from PLN has returned to normal condition. ATS components consist of voltage and current sensors, microcontroller and relay respectively. ATS use microcontroller Arduino Uno ATmega328 type to control the main switch (relay) automatically. The test results show that ATS succeeded in moving the source of electrical energy from PLN to SPP when there is a disturbance or blackout condition and ATS will returns the source of electrical energy to PLN when conditions back to normal.

Rancang Bangun Purwarupa Pengendali Relay Menggunakan Mikrokontroler Arduino Berbasis Internet of Things

Electricity is one of the essential needs for human life, as almost every activity humans engage in involves the use of electric energy. The advancement of technology in the field of computers has enabled humans to have a forward-thinking mindset in the application of electronic devices. The development of sophisticated technology that can remotely control household electronic devices such as lights using the Internet of Things (IoT) aims to save electrical energy used in each home. IoT serves as a transmission medium for embedded computing devices that are individually identified within the internet infrastructure. The control system in this research is designed through the relay circuit control method using the Arduino ATmega328 microcontroller as the central control unit of the system. It is supported by the ESP8266 WiFi module, which functions as a communication tool between the microcontroller and the wide-ranging interconnection network via WiFi, collaborating through a user interface design for an Android-based application.

Controlled vibration protection systems: optimization and energy efficiency

The energy efficiency of controlled vibration protection systems is defined as the ratio of the vibration safety indicator they achieve to the cost of energy resources necessary to achieve the desired indicator. To solve the optimization problems of controlled vibration protection, a sufficient condition for the optimality of the accepted functional and, accordingly, the minimum principle, was used, the step-by-step implementation of which, in the course of numerical integration of the initial equations of the state of the system, makes it possible to reproduce the optimal control numeric arrays and the related components of the system state. The algorithm of the step-by-step procedure of the minimum principle was used to optimize the dynamic processes in the vibration protection system with indirect control of the viscous resistance damper and the potential energy recuperator. It has been established that the optimal controls that allow eliminating resonant phenomena in these systems are positional functions of a singular type, the relay switching of which in vibration protection systems with a controlled damper and recuperator is associated with a change in the sign of the absolute and relative velocity of the object and with a change in the sign of the velocity and relative displacement of the object.

An Adaptive Centralized Protection and Relay Coordination Algorithm for Microgrid

To meet the increased customer demands, microgrid evolved. The structure of microgrid changes dynamically due to the intermittent nature of renewable-based generation, status of the distributed generator and opening of breakers for fault/maintenance. Hence, the magnitude of fault current is dynamic in nature. In order to deal with these dynamic changes, this paper addresses an adaptive central microgrid controller-based protection and relay coordination scheme, which revises the relay settings dynamically (both radial and looped configuration) for every change in topology. In the proposed algorithm, the primary relay responds to a fault immediately since the individual relays are given with fault level setting. For any abnormality in the network, the fault location is determined both via local relay and microgrid central controller (MCC). Hence, even though the local relay fails to identify the fault due to high fault impedance, the MCC locates the fault accurately and isolates the minimum faulty part. The coordination between relays is carried out by MCC in a time-graded manner based on microgrid central protection and relay coordination algorithm. The proposed algorithm is tested using Matlab in a microgrid built based on the IEEE 33 bus distribution network.

Automated Water Heating Management with Internet of Things

IoT devices can range from smart home devices such as thermostats and security systems to industrial control systems used in manufacturing and other industries. One focus of the IoT-based monitoring and control concept is monitoring and controlling water heaters based on IoT technology to support the creation of a smart home. The purpose of this research is to create a system that can control and monitor water heaters remotely using the Android Studio application so that the water temperature in the heater can be ensured for safety, comfort, reliability, and energy efficiency. The system is designed using temperature sensors and water flow sensors, and then the data is processed with the NodeMCU microcontroller and then sent to the Firebase website to be displayed on the application. The application built can set a large amount of water and heat it to the desired temperature before sending it to Firebase and then to NodeMCU. The result of this research is an application that is able to control and monitor a water heater with an average measurement difference of 0.38 liters and an average error percentage of 7.11% The relay control system in the application has an average delay time of 3.6 seconds.

Improvement of microprocessor voltage control relay operation algorithms for single-phase household consumers

This paper pays attention to a single-phase voltage control relays work algorithms that are used for protection of the household consumers of electrical energy from unacceptable voltage deviations within power supply network. An overview, analysis and description of operation algorithms, voltage measurements and thresholds of current voltage control relays, based on microprocessors and microcontrollers have been carried out. The conducted overview and analysis systematizes information on the technical and functional features of the operational design, work algorithms, circuits and components of the mentioned relays and demonstrates the prospects for development of voltage relay operational algorithms and protective characteristics according to existing International standards. The protective characteristics and standards of power quality have been outlined and illustrated by the authors in detail. The voltage measuring and digital signal processing (signal filtering) algorithms in modified voltage relay are described as well. Also represented a novel approach in design of operation algorithms taking into account of positive sides in existing voltage control relays and new sintesed algorithms including concept of voltage measurement and decision making algorithms for a new single-phase voltage control relays for household consumers. A generalization and conclusion are made concerning the improved operation algorithm in the voltage control relay for protection of household consumers.

Finite‐time tracking control of disturbed non‐holonomic systems with input saturation and state constraints: Theory and experiment

AbstractThis article investigates the finite‐time tracking control problem for disturbed non‐holonomic systems with input saturation and state constraints. Input saturation is ensured by utilizing saturated state feedback and designing auxiliary variables. A rigorous design procedure, which combines barrier Lyapunov function‐based backstepping and neural networks, is introduced to satisfy state constraints and overcome the influence of lumped disturbances. A finite‐time filter is developed to address the explosion of complexity problem. Together with relay switching, the designed saturated controller guarantees that the tracking errors converge to arbitrarily small neighbourhoods around zero within a finite time. Stability analysis indicates that all closed‐loop system signals maintain bounded, and the desired input and state constraints are not violated throughout the control process. To demonstrate the effectiveness of the proposed approach, simulation and experimental results on a wheeled mobile robot are presented.

PI/PID Controller Relay Experiment Auto-Tuning with Extended Kalman Filter and Second-Order Generalized Integrator as Parameter Estimators

PI/PID Controller Relay Experiment Auto-Tuning with Extended Kalman Filter and Second-Order Generalized Integrator as Parameter Estimators

Determination of modern reliability indicators of relay protection and automation devices

RELEVANCE. The reliability of power supply to consumers depends on the reliability of all elements of the power supply system, including relay protection and automation devices (RZiA). Knowing the current values of the reliability indicators of various devices makes it possible to take them into account when designing RPA, choosing more reliable devices, identifying shortcomings in RPA and performing work to eliminate them. THE PURPOSE. Due to the lack of open data on the current values of reliability indicators of relay protection and automation devices (RPA) of electric networks of 10-110 kV, the question of their determination on the example of power systems of various regions is relevant. METHODS. The authors present and analyze official statistical data on the number of emergency failures, false and correct actuations of relay protection and automation devices in the electric grid organization - branch of PJSC «Rosseti Center» – «Ore lenergo» for 2013-2021. RESULTS. In the course of the study, numerical values of the following reliability indicators of relay protection and automation devices were determined: the failure rate and the frequency of excessive triggering. Relayprotection and automation devices, for which reliability indicators have been determined, are used to implement arc protection, maximum current protection, automatic re-activation, differential protection of buses and transformer, transverse directional differential protection, gas protection of transformer, differential-phase protection. CONCLUSION. The values of the failure flow for different types of relays and microprocessor devices of the RPA are established, for example, for an electromechanical relay of the DZT-11 type used to implement differential protection of transformers with a higher voltage of 110 kV, the failure flow is 0,2 year-1/100 pcs., and the frequency of excessive triggering is 22,22 year-1/100 pcs. Conclusions are drawn about the need for measures to regulate the settings and maintenance of devices of various types.

A sensor‐based assistive technology for lower‐limb‐disabled agricultural workers and abled female workers for tractor clutch and brake operation

AbstractAgricultural mechanization although reduces the food demand and supply gap through improved and smart technologies, it also risks the lower‐limb disability of workers due to accidents that restrict them to participate in agricultural operations due to the unavailability of appropriate assistive technologies. The lack of use of ergonomics further minimizes the inclusion of female workers in farming operations. Therefore, this study is focused on the development of a sensor‐based wireless hand control system for tractor clutch and brake operation to assist lower‐limb‐disabled agricultural workers and abled females in tractor operation. Actuation force and speed of conventional clutch and brake pedals were evaluated using an integrated foot transducer and used as a reference for the design of the system (clutch: 92–310 N, 36–43 mm/s; brake: 106–329 N, 57–63 mm/s). The hand control system consists of a transmitter and a receiver node incorporating a single‐board computer, matrix keypad, voltage regulators, relay switches, wireless communication through radio frequency modules, and electric linear actuators connected with the pedals through L‐shaped clips, nuts, bolts, and chains. The response time of the developed system was determined as 100 ms and the stopping distance of the tractor using the hand control system ranged from 44.0 to 190.7 cm at a forward speed of 2.1–7.9 km/h. The ergonomic evaluation measured using the K4b2 oxygen analyzer identified the foot control usage in tractors as high energy consuming (9.7–15.1 kJ/min) compared with the hand control usage (7.3–14.1 kJ/min). Electromyography‐root mean square (EMG‐RMS) of upper limb muscle, extension digitorum was found to be highest (14.76–45.29 µV) and was significantly affected by forward speed, gender, subjects, and type of control (p < 0.01) whereas, EMG‐RMS of other selected upper limb muscles, middle deltoid, flexor carpi radialis, and brachioradialis was not significantly affected by the type of control (foot or hand). Muscle workload of all the muscles was observed within the recommended limit (<30%) during the tractor operation with the developed hand control system. The developed hand control system provides options to bypass foot‐based actuation requirement for lower limb disabled as well as female workers. The novel design requires minimal workplace and operating forces and is inclusive of operator ergonomics.

Hardware Circuit Design of Intelligent Induction Control Classified Garbage Can

This design is based on the STC89C52RC single chip microcomputer and the integration of various multi-function modules to complete the overall system control. It is composed of the core modules of humidity detection, relay drive, metal detection, intelligent alarm, MQ-2 smoke sensor, infrared sensing, ultrasonic detection, etc. We collect specific information through ultrasonic testing, and LCD1602 displays the current status; an infrared sensor and a smoke sensor are used for relevant monitoring; a humidity sensor and metal sensor automatically remind us to classify and put garbage; a relay analog control trash can automatically open and close. The system has the characteristics of ideal performance, low cost, convenient design, simple structure, and intelligence. It has found a feasible solution for the current environmental pollution problem to do garbage classification and treatment. It can play an important role in smart homes, smart campuses, intelligent transportation, telemedicine, and other fields, and will have a broader market prospect and application fields.

Establishment of new automated multi range thermal current converter

<p>A new automated multirange thermal current converter (TCC) has been designed and implemented at the National Institute of Standards (NIS), Egypt. Five single junction thermal current converters (SJTCCs) have been connected in parallel on PCB with an LCD, keypad and a microcontroller to control a five fast switching relays. This TCC has been designed to cover the ac current ranges from 500 mA to 5 A at frequencies from 40 Hz up to 100 kHz. The construction of the new automated TCC has been presented to solve some problems of using shunt resistance at high currents. Furthermore, a new automatic calibration system has been established to calibrate the established TCC against another standard TCC. This software program has been specially designed using MATLAB program to overcome the problems of manual calibration and measurement. The expanded uncertainties are estimated for all ranges at different frequencies and also, the ac-dc differences. The performance of the new automated TCC is also evaluated by comparing its accuracy by measuring ac currents at different frequencies with the performance of a traditional TCC.</p>