Relay Design Research Articles

Optimal coordination of directional over current relays for distribution systems using hybrid GWO-CSA

Coordination of protective relays is a critical aspect of electrical distribution systems, ensuring effective and reliable protection against faults. In modern power systems, the integration of distributed generation (DG) sources adds complexity to the coordination task. The dynamic nature of DG systems requires adaptive relay settings that can swiftly detect and isolate faults while minimizing potential damage and downtime. The purpose of this research is to improve the coordination of directional over current relays in electrical distribution systems, particularly in DG systems. An optimization technique combining the grey wolf optimization (GWO) and cuckoo search algorithm (CSA) is developed to identify the best relay settings that reduce overall operation time while ensuring excellent fault identification and isolation. To address relay faults caused by DG integration, a suitable primary and backup relay design is chosen, and the influence of time multiplier settings (TMS) on system performance and reliability is investigated. The proposed GWO-CSA technique is evaluated and implemented on IEEE 3, 8 and 15-bus systems using MATLAB. Simulation results show that the GWO-CSA strategy outperforms well compared to previous algorithms, enabling optimal coordination and increased protection in DG systems while drastically lowering relay operating time.

Abstract 6633: Tracking cell-cell interactions using intercellular barcode transfer

Abstract Cell-cell interaction is one of the fundamental biological mechanisms by which cells communicate and is a key modality by which cancer cells interact with other cells in their microenvironment. Current methods, such as enzymatic labeling and proximity-based tagging, allow the experimental tracking of these interactions but are not compatible with sequencing-based readouts, which are essential for high-throughput analyses. We have developed a highly scalable intercellular barcode transfer technology that bridges this gap. Our novel “Relay” technology offers a scalable solution to monitor cell-cell interactions with unprecedented single-cell resolution, seamlessly integrating with existing high-throughput and sequencing platforms. Relay employs RNA barcodes to mark and track cell interaction events, providing definitive quantitative data on cell interaction partners. We used Relay to track interactions between cancer cells and T cells, capturing both potent antigen-specific engagements and subtler contacts involved in antigen sampling. Additionally, by integrating CRISPR libraries with Relay, we pioneered a novel approach for pooled CRISPR screens, focusing on intercellular interactions across different cell types. In this context, the cell harboring genetic perturbation may differ from the cell under analysis. To demonstrate this, we are conducting genome-wide perturbations in cancer cells and interrogating cancer cell factors that affect antigen sampling and trogocytosis by T cells and macrophages. Beyond its application in CRISPR screening, Relay can also be used with single-cell RNA sequencing to directly track and measure immune-cancer and immune-immune cell interactions at the single cell level. We applied single-cell Relay to a dendritic cell-T cell system to link dendritic cell signatures to T cell signatures based on direct cell contact and regulatory signaling. The design of Relay as a highly modular system extends its utility beyond cancer research, making it broadly applicable across various biological models and systems where cell-cell communication is a fundamental property in complex multicellular settings. This tool promises to accelerate the transition from theoretical understanding to practical exploration of cell-cell interactions, with profound implications for immunology, oncology, and beyond. Citation Format: Neil Q. Tay, Tiffany Juan, Joseph J. Muldoon, Justin Eyquem, Michael T. McManus. Tracking cell-cell interactions using intercellular barcode transfer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6633.

Application of Amorphous and Nanocrystalline Soft Magnetic Materials in Balanced-Force-Type Electromagnetic Relay.

The magnetic properties of soft magnetic materials, including their saturation magnetic induction strength and permeability, significantly affect the dynamic characteristics of electromagnetic relays. However, the soft materials most commonly used for relays in the magnetic conductive components of electromagnetic systems, such as electrical pure iron, limit further relay design improvement and optimization to a certain extent. Thus, this paper proposes the use of amorphous and nanocrystalline soft magnetic materials with good high-frequency magnetic properties in magnetic circuits. A wavelet analysis was conducted on the high-frequency components of the coil current while the relay operated, and the corresponding magnetic materials were selected. Considering the challenges in processing amorphous and nanocrystalline materials and collecting test data for the accuracy verification of simulation methods, we prepared a scaled-up prototype for use in dynamic characteristic tests. The simulation method was improved, yielding more accurate simulation results regarding the relay's dynamic characteristics. On this basis, six replacement schemes using amorphous and nanocrystalline materials were considered. The test results proved that this application could improve the relay's dynamic characteristics. Finally, a full-size sample with an iron core consisting of nanocrystalline alloy 1K107B was prepared, and the conclusions were verified in tests.

Multi agent system based adaptive numerical relay design and development, Part II: Hardware

Multi agent system based adaptive numerical relay design and development, Part II: Hardware

Extend low-power LoRaWAN coverage device for IoT applications

The advent of Long Range Wide Area Network (LoRaWAN) has significantly enhanced Internet of Things (IoT) applications, particularly in Smart Cities, with its broad coverage and energy efficiency. However, in areas with blind spots and obstacles, the conventional star network has limitations in coverage. To overcome this, researchers conducted a study to explore the potential of LoRaWAN extenders with multiple relays, focusing on coverage, performance, and power consumption. The study involved designing and deploying a relay system aligned with protocol of LoRaWAN to extend the reach of a standard LoRaWAN gateway. Strategically placed relays addressed areas beyond the gateway's coverage. Performance was measured by the longest communication distance achieved by each relay, packet loss ratio, and latency. Power consumption was also monitored. The results demonstrate the practicality and effectiveness of the proposed multiple relay design, expanding the capabilities of LoRaWAN network.

TRIAC Based Isolated AC Load Drive Equivalent Circuit Design of Solid-State Relay

Electronic main boards generally provide the supply and control functions of a system. All electronic main boards include inputs and outputs and are designed according to the design requirements. In this study, a safe and low-cost switching mode power supply (SMPS) board is designed using a flyback converter topology to drive the AC and DC outputs. The triode for alternating current (TRIAC)-based safe and low-cost main board includes a flyback configured transformer with additional winding for driving the TRIAC as an AC output switch in noise immune quadrants II and III. TRIAC is used to switch AC outputs instead of a relay, and the isolation distances of the safety criteria are provided by an optocoupler. In this way, the relay usage is over, and one TRIAC and one optocoupler do the same work that is done by one relay. In this way, the cost of the AC output switch decreases. In addition, the number of AC switches covering the area on the printed-circuit board (PCB) of the mainboard decreases. The flyback topology is designed with half-wave rectified and the transformer is designed with extra winding for producing negative voltage with respect to primer reference for providing negative gate current of TRIAC. TRIAC-based AC output switched, safe, and low-cost main boards can be used for white good main boards, automation (PLC) applications, and automotive electronic control systems. This study provides cost-effective solutions in these areas.

Coordinated Overcurrent Relay Development with Arduino and ACS712

This study presents the design and evaluation of an overcurrent relay system using Arduino Uno, ACS712 current sensors, and electromagnetic relays. Conducted at the University of Negros Occidental–Recoletos, Philippines, from March 2023, the research focuses on developing a relay with accurate trip times and reliable performance. The designed relay features multiple characteristics including Standard Inverse, Very Inverse, and Extremely Inverse, with time delays ranging from 20 ms to 100 ms and time multiplier settings from 0.1 to 0.23. Testing results showed that the Extremely Inverse characteristic achieved the fastest trip time of 0.11 seconds at 9.3 A, while the Normal Inverse characteristic had a trip time of 1.04 seconds at 1.7 A. The relay's error margins were well within the 5% tolerance limit set by IEC 60255 standards, with errors ranging from 0.027 to 0.028. Effective coordination was achieved by adjusting the Time Multiplier Setting (TMS) values to ensure fault isolation without disrupting other system components. The results confirm that the relay design is both accurate and reliable, suitable for practical implementation in electrical protection systems. Future work could involve integrating additional functionalities and testing under diverse environmental conditions.

Physical Layer Security for Frequency Diverse Array-Based Dual-Hop Spatial Modulation

In this paper, we design the physical layer security of a dual-hop spatial modulation system provided the relay node transmits its own private information. Meanwhile, the quadrature virtual channel spatial modulation (QVCSM) is proposed to enhance the physical layer security in the second hop. To achieve system security in both angle and range dimensions, the frequency diverse array (FDA) is used in the relay node with a decode-and-forward (DF) protocol. Moreover, the baseband directional modulation (DM) and artificial noise (AN) are jointly utilized to suppress the received signal at the passive eavesdropper. Additionally, the Ergodic secrecy rate of the proposed system is analyzed, whereas the closed-form expressions for tight upper bounds on the bit error rates (BERs) of the source and relay are derived for both the destination and eavesdropper. The simulation results show that the proposed FDA relay design outperforms the traditional phase array (PA) relay system in terms of the system secrecy rate. In contrast to the quadrature spatial modulation (QSM) method, the proposed designs achieve an improved suppression performance of the eavesdropper.

Multiagent System-Based Adaptive Numerical Relay Design and Development: Part I - Firmware

Protection relays that incorporate advanced microprocessors are vital to electrical grids, providing fast and reliable responses to faulty conditions using efficient communication protocols. Instant detection and response to various faults are essential to minimise the risk of damage. Numerical relays can identify faulty conditions and trigger circuit breakers to open, thus preventing further damage to the system. Due to the lack of autonomous decision-making capabilities, existing numerical relays require manual reconfiguration in situations such as a change in network configuration and protection settings. These relays also do not have the ability to coordinate fault clearance when multiple sources supply power to the grid. A comprehensive overview of the research aimed at developing a multiagent system (MAS)-based adaptive protection relay will be provided by dividing it into separate articles such as firmware and hardware. This first part delves into the firmware aspects of this innovative relay, highlighting its adaptive capabilities and key considerations in its development. The second part will provide detailed design descriptions for the hardware features of the relay. An STM32MPU multicore advanced microprocessor is utilised to design and develop the adaptive numerical relay firmware. It incorporates several protection relay ANSI codes, communication protocols, and MAS-based adaptive protection schemes as part of the firmware.

Relay network design with direct shipment and multi-relay assignment

Relay network design with direct shipment and multi-relay assignment

Design of a fuzzy distance relay taking into consideration the impact of using a unified power flow controller

The compact design of a fuzzy distance relay, which includes its impact on using a unified power flow controller in a power system, has been adopted as the object of the study. Traditional power system grids have increasingly widely used flexible alternating current transmission system devices in recent years to increase power system stability when faults, unbalance, and sudden changes in load occur. This plays a role in improving power quality, power factor corrections, and power flow control. A unified power flow controller is one of these devices that is most used, popular and meets these benefits, but it simultaneously gives a different change in the apparent impedance of the protection system due to its design. To overcome these issues, the proposed novel design of a fuzzy distance relay is made with the assistance of MATLAB® Simulink and Neuro-Fuzzy Designer. The proposed design work was divided into three parts, the first without fault and the second one including four scenarios without using and using a unified power flow controller in different transmission line locations. The design was carried out in the third part after collecting all input-output data sets. This paper offers an efficient design method, which depends on the input value of the observed apparent impedance, also known as resistance (R), and reactance (X). The output is a trip signal to the circuit breaker when a fault occurs. The advantages of the proposed design are a fast-clearing time of 1.42 ms, and working when utilizing a unified power flow controller in different locations; the results show a fast clearing although the long impedance trajectory for some cases. The fast fault clearing will make the system more stable and overcome the maloperation of the distance relay

Faults detection, location, and classification of the elements in the power system using intelligent algorithm

This study proposes an intelligent protection relay design that uses artificial neural networks to secure electrical parts in power infrastructure from different faults. Electrical transformer and transmission lines are protected using intelligent differential and distance relay, respectively. Faults are categorized, and their locations are pinpointed using three-phase current values and zero-current characteristics to differentiate between non-earth and ground faults. The optimal aspects of the artificial neural network were chosen for optimal results with the least possible error. Levenberg-Marquardt was established as the ideal training technique for the suggested system comprising the differential relay. Levenberg-Marquardt was the optimal training technique for the proposed framework consisting of the differential relay. Fault detection and categorization were performed using 20 and 50 hidden layers, and the corresponding error rates were 9.9873e-3 and 1.1953e-29. In the context of fault detection by the distance relay, the hidden layer neuron counts were 400, 250, and 300 for fault detection, categorization, and location; training error rates were 7.8761e-2, 1.2063e-6, and 1.1616e-26, respectively.

Design and Performance Evaluation of Numerical Relay for Three-Phase Induction Motor Protection

Design and Performance Evaluation of Numerical Relay for Three-Phase Induction Motor Protection

Implementing a non-4f relay system for Hartmann-Shack wavefront sensing.

Hartmann-Shack wavefront sensors (HSWSs) are used in many disciplines to measure optical aberrations. Conventionally, the wavefront of interest is transferred onto the lenslet array of the HSWS with a telescopic 4f relay system. However, the 4f relay design restricts the choice of focal lengths and distances used for the relay system. In this paper, we describe a non-4f variant and demonstrate both theoretically and experimentally that its wavefront relaying properties equal that of a 4f system. We also present an alignment method for conjugating the wavefront with the lenslet array of the HSWS for both 4f and non-4f systems.

Development of a Semiconductor Time Relay for Locomotives

Purpose. The need to replace the outdated element base of locomotive electrical apparatuses is urgent under conditions of locomotive overhaul to extend their service life. The main aim of the work is to reduce costs for the operation and repair of rolling stock by increasing the reliability of electrical apparatuses, the introduction of unified technical solutions. Methodology. Using the system-historical approach, the advantages and disadvantages of the main design principles of electrical apparatuses of locomotives are found out. The improvement directions of the elemental base of the time relay have been determined. The need to develop unified technical solutions for the implementation of locomotive time relays is substantiated. Using the methods of applied theory of digital machines and circuit engineering, a semiconductor time relay for locomotives was developed, which provides the possibility of implementing 23 options for time delay without changing the relay design. The proposed methodology allows designing universal electronic relays with any ranges of time delays. A combination of binary counters and a multiplexer is used as the main elements of the time delay control. The absence of elements of control capacitance and active resistance (RC circuits) in the scheme of the proposed semiconductor time relay allows ensuring the stability of the time relay characteristics over the entire operating interval, reducing the maintenance and repair costs of electrical apparatuses. Findings. A unified time relay with a wide range of time delay and the possibility of connecting electrical circuits of locomotives with a supply voltage of 50 and 110 V has been developed. The obtained results make it possible to predict the further development of semiconductor time relays and to apply the developed semiconductor (electronic) time relay for all types of railway rolling stock. Originality. In the work, the development of technologies and the element base of locomotive electrical apparatuses were analysed. The need to improve the element base of electrical apparatuses is substantiated using a time relay example. Practical value. Based on the proposed technical solutions, it is possible to produce a universal semiconductor time relay for locomotives.

3-D coarse-grained reconfigurable array using multi-pole NEM relays for programmable routing

We propose the use of multi-pole nanoelectromechanical (NEM) relays for routing multi-bit signals within a coarse-grained reconfigurable array (CGRA). We describe a CMOS-compatible multi-pole relay design that can be integrated in 3-D and improves area utilization by 40% over a prior design. We then demonstrate a method for placing multiple contacts on a relay that can reduce contact resistance variation by 40× over a circular placement strategy. Additionally, we develop static and dynamic SPICE models (calibrated to accurate finite element models) for predicting circuit-level performance with these devices. Finally, we establish a methodology for integrating these relays into an industry-standard digital design flow. Using our multi-pole relay design, we perform post-layout simulation of a hybrid CMOS-NEMS CGRA processing element (PE) tile in 40 nm technology. We achieve up to 19% lower area and 10% lower power at iso-delay, compared to a CMOS-only CGRA PE tile. The results show a way to bridge the performance gap between programmable logic devices (such as CGRAs) and application-specific integrated circuits using NEMS technology.

Design and Implementation of Differential Relay Based on Graphical User Interface

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

A Photo-responsive Transmembrane Anion Transporter Relay.

Ion transport across lipid membranes in biology is controlled by stimuli-responsive membrane channels and molecular machine ion pumps such as ATPases. Here, we report a synthetic molecular machine-like ion transport relay, in which transporters on opposite sides of a lipid bilayer membrane facilitate transport by passing ions between them. By incorporating a photo-responsive telescopic arm into the relay design, this process is reversibly controlled in response to irradiation with blue and green light. Transport occurs only in the extended state when the length of the arm is sufficient to pass the anion between transporters located on opposite sides of the membrane. In contrast, the contracted state of the telescopic arm is too short to mediate effective transport. The system acts as a stimuli-responsive ensemble of machine-like components, reminiscent of robotic arms in a factory assembly line, working cooperatively to mediate ion transport. This work points to new prospects for using lipid bilayer membranes as scaffolds for confining, orientating, and controlling the relative positions of molecular machines, thus enabling multiple components to work in concert and opening up new applications in biological contexts.

Modelling and performance testing of a digital over-current relay enhanced designed model

Introduction. The over-current relay is widely used to protect distribution and transmission electrical systems against excessive currents occurring due to short circuit or overload conditions. Many works have been carried out in the field of models simulation design of digital over-current relays in the literature, but unfortunately many of them are more complex design models, have very slow execution time and only work in simple faults cases. Purpose. The purpose of this work is to present the performance of a modified and improved model of a digital over-current relay designed in Simulink/MATLAB environment with more simplified design, faster execution time, and able to operate under more complex fault conditions. Methodology. Before starting tests, modelling of over-current relay is presented in details, of which the basic logics of the proposed model to implement inverse and instantaneous characteristics are well explained. Afterwards, various tests are carried out for the performance analysis of the enhanced designed relay model in terms of: operating speed for eliminating faults that has arisen, ability to distinguish between a fault current and load starting current, capacity distinguish between real and temporary fault currents, the way to manage variable faults over time, and the degree of harmony between primary protection relay and back-up protection relay. Originality. The originality of our proposed work consists in the development and improvement of a digital over-current relay model designed in Simulink/MATLAB environment in such way that it becomes able to operate under new harsh test conditions. This developed designed model is implemented and applied in a 400V radial distribution power system with a load that causes a starting current. Results. The obtained values of simulation are compared with the theoretically calculated values and known existing models. The obtained results after various tests validate the good performance of our enhanced designed model.

Finite-Order Filter Designs of Source and Multiple Full-Duplex Relays for Cooperative Communications in Presence of Frequency- Selective Fading and Inter-Relay Interference

This paper considers the finite-order filter design problem for the source and multiple full-duplex (FD) relays in a cooperative communication system under frequency-selective fading channels. The goal is to optimize the source and relay filters such that the end-to-end signal-to-interference-plus-noise ratio (SINR) of minimum mean-squared error decision-feedback equalizer (MMSE-DFE) can be maximized. The resultant design problem is very difficult since we need to deal with self interference (SI), inter-relay interference (IRI), and inter-symbol interference (ISI) at the same time. Novel designs are then proposed to overcome the difficulty in this work. Transforming the signals into the frequency domain and using some optimization techniques, we first theoretically derive the power spectrum of the source filter and the spectrums of the relay filters. Then, the finite-order design is developed to approach the derived spectrums. Based on the weighted least-square (WLS) criterion, the Steiglitz-McBride method is exploited to obtain the filter coefficients in finite lengths. Numerical results demonstrated that complete removal of SI may not be a good strategy; preserving a certain amount of SI at each relay instead provides better SINR performance.