Current Relay Research Articles

DEVELOPMENT AND APPLICATION OF A WEARABLE TECHNOLOGY PRODUCT THAT DETECTS AND INFORMS THE PRESENCE OF ELECTRICAL ENERGY

Electrical energy has both positive and negative effects nowadays, with the potential to cause property and human loss. Technical professionals working at electrical energy generation, distribution, and utilization points may die due to carelessness or neglect. Although there are protection elements (fuses, residual current protection relays, etc.) in electrical panels that interrupt the flow of electrical energy in the event of a shock, there may be working areas where energy cannot be cut off due to incorrect electrical connections caused by unauthorized people interacting with the panel. Existing protective components may be insufficient. The experiments include both wired protection elements and wireless detection elements. However, they need to be enhanced because they have limited detection distances. Furthermore, using an ergonomic design can improve operability. New protection and warning features must be designed using developing technology. To prevent employees from being shocked by being exposed to electrical energy in the workplace, AC voltage can be detected without contact using this study, which includes the design and test results of a wearable technology product that warns when electricity is present. An electrical circuit that technical staff can wear on their finger detects voltage without contact and displays the existence of energy with a red LED. It was discovered that the test circuit detects 230V AC electrical energy up to 8 cm away and warns with light.

Study on the influence of transverse magnetic field on the arc and reignition characteristics of HVDC relays

It is of great significance to clarify the influence of transverse magnetic field (TMF) on arc control in high-voltage direct current (HVDC) relays. In this paper, the influence of TMF in a wide range of 0–140 mT on the arc characteristics of HVDC relays is studied, the experimental observations of arc reignition are carried out and the effect of arc reignition on contact erosion, the criterion of arc reignition and the mechanism of TMF enhancement on arc reignition are further analyzed. The results show that the TMF enhancement is beneficial for shortening the arc voltage stagnation duration and accelerating the speed of arc elongation, arc dispersion and dispersed arc motion, thereby improving the arc extinguishing performance. However, higher TMF leads to more severe and earlier arc reignition, as also shown in the experimental observations. The arc reignition further causes a sudden drop in arc voltage, prolonged arc duration and uneven contact erosion. To evaluate the occurrence of arc reignition caused by TMF enhancement, a simplified breakdown criterion is proposed through the defined characteristic variable C¯(t) . Based on this, the mechanism by which the TMF enhancement more easily causes arc reignition is explained, that is the higher TMF leads to an earlier and faster increase in C¯(t) and slightly reduces the breakdown threshold C¯∗(t5,D) . Further, measures to suppress the arc reignition are proposed.

The Evaluation of Over Current Relay and Ground Fault Relay Settings on Power Transformers

Power transformer is an important component of the substation and has an important role in the electric power distribution system. During operation the power transformer can’t be isolated from distribution system when abnormal conditions or faults occur. A fault in the power transformer will have huge impact on the power transformer itself. The substation has an installed capacity of 60 MVA of power transformers, and during operation there is a possibility of relay failure, which may interrupt the power distribution process to the load. To avoid this failure, it is necessary to analyse the settings of Over Current Relay (OCR) and Ground Fault Relay (GFR) on the 60 MVA transformers. The analysis was carried out by simulating short circuit faults of the electrical system in the ETAP software application, and then configure the setting of the relay by referring to the magnitude of the short circuit current value for phase to phase and phase to ground. The results of this analysis are used as a reference to determine the OCR and GFR relay values in the power transformer. The results obtained show that the recommended value for OCR setting on 150 kV power transformers is 0.92 second while for GFR is 0.96 second, and for the 20 KVA power transformers the OCR and GFR setting values are 0.40 and 0.20 seconds respectively. Comparison based on the results of the setup data and the analysis data has carried out, there is difference in the working time of the relay, with a difference of 5%, where the value of the analysis results is not much different from the conditions in the field.

Evaluasi Kinerja Sistem Proteksi Penyulang Trawas PT. PLN (PERSERO) ULP Pandaan

The primary objective of this research was to minimize disruptions in the feeder at ULP Pandaan by analyzing the coordination between recloser outgoing and incoming feeders. This study addressed the frequent issue of recloser trips, which caused instability in power supply. The purpose of this research was to provide conclusions and solutions to mitigate these disruptions. The methodology involved a detailed analysis of OCR (Over Current Relay) settings for protective devices on Trawas feeder. This included measurements of primary current settings and TMS (Time Multiplier Setting) values using both standard inverse and normal inverse configurations. Specific settings, such as 25518 A for the Trawas Recloser primary current and a TMS of 0.07, were determined to yield optimal performance. Additional settings for the Outgoing CB (Circuit Breaker) (357061 A, TMS 0.04) and the Incoming CB (181865 A, TMS 1.0) were also established. The important findings revealed that these settings significantly enhanced the reliability of the protective devices, ensuring better coordination between the recloser and CB systems. The implications of this research were substantial, as the optimized settings were expected to reduce the frequency and impact of feeder disruptions. This improvement in system reliability directly benefited both the electricity provider, PT. PLN (Persert), and the consumers by providing a more stable and efficient power supply. In conclusion, this study offered a comprehensive analysis and practical solutions for enhancing the protection system's performance on the Trawas feeder, which could be applied to similar electrical distribution networks to achieve better stability and reliability.

Three phase microcontroller based automatic change-over selection switch

The significance of electricity in a developed country cannot be underestimated because power instability problem affects the economy growth, productivity and infrastructure development. The issues of phase failure, losses and phase imbalance earth fault are main causes that lead to unstable and erratic power supply. Most homes and office complexes where single-phase supply is needed are supplied with three phases of power supply to allow change from one phase to another when there is fluctuation or complete outage of power supply on a particular phase. This operation is normally done manually and has caused a setback in terms of time wastage, strenuous operation, susceptibility to fire outbreak, electric shock and high maintenance frequency. When voltage supply on a phase is below 220V or above 415V, this system automatically disconnects the load from the phase and connects to another where the required condition is met. Therefore, this paper presents a Microcontroller Based Automatic Transfer Switching System which is made up of voltage sensing circuit, Hall Effect current sensor, relays, LEDs and LCD of PIC16F877A microcontroller. A system flow chart was developed, programmed with MikroC software and simulated using Proteus electrical software design. A 10KVA single phase generator was used as alternate power source. The load capacity of the design was determined by decoupling Maxwell’s Equations of 8KW and power loss using pointing vector equation as 0.25% of the peak load. The switch is tested to have function optimally within ±5% nominal voltage of 220 - 415V supply and produced approximately 20 seconds elapses during the entire process of power supply changeover. Hence this device is suitable for Industrial and Domestic use where 3-phase power supply is available with a stand-by power source.

Analysis of Dynamic Parameters of the Switching-On Process of Electromagnetic Relays Powered by Harmonic Polluted Voltage Source

The article incorporates an analysis of the switching-on process of alternating current (AC), low-voltage (LV), and electromagnetic (EM) relays energized by harmonically polluted voltage sources. In the undertaken research, the dynamic parameters of relays actuated by electromagnetic drive were examined for shape and supply voltage waveform distortion levels as described by different THD factor values. During the research, diverse supplying voltages were delivered to drive electromagnet coils at a variety of phases so as to reflect the stochastic nature of the energizing procedure. The performed analysis allowed for determining the most influential and decisive factors dictating the basic parameter values of the switching-on process. As an outcome, time-related parameters of relay moving armature movement were obtained, and the frequency of disorder occurrences during the switching-on was examined. For experimentation needs, an experiment stand was developed, and dedicated software for measurement results analysis was elaborated. Based on the study results, EM relay switching-on operation reliability was evaluated in view of electric energy quality.

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.

ANALISA SETTING PROTEKSI OVER CURRENT RELAY (OCR) PADA GENERATOR 30 MW UNIT PLTA POSO PT. POSO ENERGY

To ensure that the performance of the protection system is still good or not in terms of protection, calculations and adjustments must be made to the safety relay settings, especially the over current relay. In the research, analysis of the over current relay protection settings on the 30 MW generator at the Poso 1 PT PLTA unit. Poso Energy obtained that the maximum load current data on the generator was 2042 A, while the calculation results obtained were 2041.7 A. For the relay (top) operating time in the specification data, the value was 1.4 s, while in the calculation results it was 1.3 s. And for the setting current (Is) in the specification data the value is 4.7 A, whereas in the calculation results it is 4.28 A. Over current relay (OCR) or over current relay is an auxiliary relay from the differential relay, the over current relay is used to secure the generator of the overcurrent in the Poso 1 PLTA is PCS-985GE-EN-H2-110V-5A. In the specification data, the TMS value is 0.15 s, while in the calculation results it is 0.14 s. This means that data in the field is slower to protect components from interference by 0.01 s. However, overall the overcurrent relay settings on the generator at the Poso 1 PLTA are still in good condition.

A DRL-Based Satellite Service Allocation Method in LEO Satellite Networks

Satellite computing represents a recent computational paradigm in the development of low Earth orbit (LEO) satellites. It aims to augment the capabilities of LEO satellites beyond their current transparent relay functions by enabling real-time processing, thereby providing low-latency computational services to end users. In LEO constellations, a significant deployment of computationally capable satellites is orchestrated to offer enhanced computational resources. Challenges arise in the optimal allocation of terminal services to the most suitable satellite due to overlapping coverage among neighboring satellites, compounded by constraints on satellite energy and computational resources. The satellite service allocation (SSA) problem is recognized as NP-hard, yet assessing allocation methods through results allows for the application of deep reinforcement learning (DRL) to obtain improved solutions, partially addressing the SSA challenge. In this paper, we introduce a satellite computing capability model to quantify satellite computational resources. A DRL model is proposed to address service demands, computational resources, and resolve service allocation conflicts, strategically placing each service on appropriate servers. Through simulation experiments, numerical results demonstrate the superiority of our proposed method over baseline approaches in service allocation and satellite resource utilization, showcasing advancements in this field.

Evaluation of Transformer Protection System Coordination at ULTG Jeneponto

Power transformers are essential components in electrical power systems as they transform electrical quantities. In practical terms, electrical power systems may experience disturbances such as short-circuit faults, either between phases or to ground. One type of relay used to accommodate these faults is the Over Current Relay (OCR) for phase-to-phase faults and the Ground Fault Relay (GFR) for ground faults. This research evaluates the coordination settings of transformer protection systems at PT PLN (Persero) ULTG Jeneponto by analyzing the characteristics plot of each transformer unit. The evaluation results reveal intersecting characteristics on the high voltage (HV) and medium voltage (MV) sides of Transformers #3 Tallasa and #3 Bulukumba. By implementing recommended settings for these two transformer units, anomalies can be addressed, and the protection system can coordinate effectively.

Optimal Coordination Of Multiple Setting Group Type Overcurrent Relays

Relay coordination optimization issues are multi-objective, multi-constrained problems that aim to reduce each relay's operation time while satisfying all relevant constraints. Fulfillment of the coordination time interval (CTI) and time limitations for relay operations are the coordination constraints. To solve coordination optimization issues, decision-making variables are defined such that the objective function is minimized with due satisfaction of necessary constraints. The majority of the most recent research that is currently available defines relay coordination for fixed network topologies, but in practice, it varies for a variety of reasons, including maintenance and element failures. Over current relays now have the capability of storing multiple relay settings but the number of relay settings that can be stored in relays is far less than the possible number of network configurations, which is why a suitable clustering technique such as K-Means can be used to cluster out various network topologies using a proper clustering index. Because both the objective function and the constraints are time dependent, time dependent attributes such as average relay operating time are used as the clustering index instead of the conventional index fault current deviation.

Assessment of Adaptive Coordinated Control of Overcurrent Relay Using Novel Multi-Trial Vector-Based Differential Evolution Algorithm

In this work, we use a unique multi-trial vector-based differentiation algorithm to examine the dynamically coordinated management of over current relays (OCRs) in substations. OCRs are significant for substation protection, and their coordinated control is essential for different sections experiencing varying current levels. Numerous optimization and AI techniques have been explored by researchers to enhance OCR coordinated control performance. This study introduces adaptive control for automatic coordination time adjustment based on forecasting, particularly focusing on integrating wind energy systems with and without reactors in substations. Accurate forecasting is vital for effective adaptive OCR control; hence, a novel multi-trial vector-based evolutionary (MTDE) algorithm is proposed for wind energy forecasting. MATLAB is used for the analysis, comparing the performance of artificial neural network (ANN)-based wind energy forecasting. The proposed method employs ANN for wind energy forecasting in a 110/22KV substation, enhancing OCR coordinated control based on wind energy integration. The ANN is trained using Mean Square Error (MSE), and its weights are tuned using MTDE for improved forecasting accuracy. Simulation results show that the MTDE-tuned ANN significantly enhances wind energy forecasting accuracy compared to conventional ANN, enabling superior adaptive coordinated OCR control, and thereby improving substation protection under fault conditions.

Cyber-Immune Line Current Differential Relays

Cyber-Immune Line Current Differential Relays

Optimal overcurrent relay coordination: Balancing costs, time performance and generator placement in fault current limiter optimization

AbstractThe integration of synchronous generators (SG) to the grid will present serious problems in some instances. The increase in fault current level is one of the most crucial issues, which causes miscoordination between directional over current relays (DOCRs), in addition to putting excessive pressure on the circuit breakers. This research uses the Fault Current Limiters (FCL) to restore coordination, without changing the settings of DOCRs, by reducing the level of fault current in the grid. The main goal of this research is to find the optimal size, location, and number of FCLs at the minimum cost and with the least operation time for the relays, using Jellyfish Search Optimisation (JSO) algorithm. This can be achieved through three different approaches. The first one is optimizing the location, number, and impedance size of the FCL by minimising a cost function. The second approach involves optimizing the backup relay operation time. A combination of the two previous approaches is used as the third approach. The outstanding feature of this research is that it considers the optimal location of DG and FCL while optimizing the operation times of DOCRs, which is a new framework.

A New Approach to Current Transformer Saturation Compensation for Transmission Line Differential Protection

A non-linear autoregressive network with external inputs (NARX) model to reconstruct the current transformer (CT) secondary waveform distortion in the presence of protected transmission lines is presented. The qualitative analysis carried out on the autonomous model reveals the accurate performance of the current differential relay, because of the ability of the NARX to make accurate predictions and signal reconstruction even when faced with noisy or incomplete datasets. The suggested method uses samples of the line-protected remote current signal to produce a desired waveform. The unsaturated section is artificially expanded because it can estimate up to one sample after saturation with a respectable level of accuracy. The proposed method is evaluated by MATLAB and PSCAD software. The effectiveness of the suggested method for different fault types under varied situations has been proved. The simulation outcome confirms the method’s high accuracy concerning the unusual system conditions in the presence of CT saturation.

Improved Over Current Relay (OCR) Coordination Using Time Multiple Setting (TMS)

Improved Over Current Relay (OCR) Coordination Using Time Multiple Setting (TMS)

Performance comparison of PSO, HGSO, and DE optimization techniques for computation of directional overcurrent relay coordination in power systems

Directional over current relays (DOCRs) have been in use for ensuring the complete protection of the power system network. However, the modern power system is getting complex with the increased penetration of Renewable Energy Source (RES) based distributed generators (DGs), as the current flow become bidirectional. Hence, the system demands faster operation of the protection devices to prevent any major outages. Optimal values of all the DOCR settings viz, TDS and Ip need to be found out such as to minimize the overall time of operation of all the relays in the network. This study focuses on the comparative study of the optimization problem carried out using the prominent optimization algorithms – Particle Swarm Optimization (PSO), Henry Gas Solubility Optimization (HGSO) and Differential Evolution (DE). The ability of techniques is established on IEEE 6 – bus & WSCC 9 – bus test systems for mid-point line faults. The Protection Coordination Problem (PCP) is formulated as non-linear programming (NLP) problem, and the optimal settings of the relays TDS and Ip are achieved using MATLAB R2021a platform and validated the results in POWER WORLD simulator software. The results depict that the HGSO method shows a significant reduction in relays' time of operation compared to PSO, but DE gives superior results compared to other techniques with a minimum computational time.

Improvement the effectiveness of multi-directional low weight solar panel tracking system based on dC relay

Rotating prototypes are utilized to track the sun path and allow solar panels to head towards the sun as long as possible, to growing additional solar power and increasing their efficiency. Therefore, to develop the suggested prototype for Advanced Virtual RISC microcontrollers, the paper suggests that instead of traditional materials like Iron and plastics, it would be possible to use foam polyvinyl chloride material. It can withstand more heat and is capable of reducing the design's weight and energy consumption in comparison to different materials. Furthermore, this work proposes that the sun position tracking is adjusted through a switch operates in a direct current relay to minimize the effects of energy expenditure in control circuits and motors. Consequently, the aforementioned operation will lead to improve the total power system and to set an optimum period for peak direct current relay. Lastly, the advantages of combining solar cells in a series on output voltage from panels are discussed in this work. The experiments revealed that the proposed prototype is more efficient than a static solar system in absorbing higher sunlight, with an average power increase of 34 %. In addition, measurements have shown that the optimal duration of a suggested tracking system can be discretized every 20 minutes in order to achieve maximum efficiency i.e. 34 %. In contrast to a system that monitors continuously, an optimum discretizing time period minimizes 89% of the power used by the moving and microcontroller units.

Enhancing grid protection: The crucial role of resistive-type superconducting fault current limiters in transmission line current differential relays

Superconducting fault current limiters (SFCLs) offer an efficient means of limiting fault currents and supporting system reliability. However, they weaken the fault characteristics and reduce the sensitivity of traditional relay protection. The seamless integration of SFCLs with protective relays remains a complex and under-explored area, impeding their widespread industrial adoption. In parallel, current differential protective (CDP) relays are almost the primary protection for all high-voltage electrical equipment and are the cornerstone of global power system security. This paper fills a critical knowledge gap by researching the intricate interaction between resistive superconducting fault current limiters (R-SFCLs) and current differential protective relays. Our investigation commences with a comprehensive mathematical analysis, while researching the influence of R-SFCLs on CDP operation. Subsequently, we conduct a series of comparative experiments using the Matlab Simulink software platform. These tests evaluate the sensitivity, dependability, and security of CDPs in scenarios with and without R-SFCLs. The simulation results not only confirm the accuracy of our analytical framework but also shed light on the multifaceted relationship between R-SFCLs and CDPs. This research contributes to a deeper understanding of how R-SFCLs can be effectively integrated into power systems, offering a roadmap for enhancing grid protection.

Fault Identification and Protection of Induction Motor Using PLC and SCADA

If not properly maintained, AC induction motors are prone to malfunction. A protective system is put in place to keep an eye on the motor's performance under both normal and trip conditions to remedy this. The system may either modify the input voltage and current to restore normal performance in the event of faults like stator, rotor, bearing, or eccentricity issues or shut down the motor before irreparable harm is done. This guards against sudden shutdowns that could endanger employees, prevents unexpected motor failure, and reduces unforeseen costs. Due to their extensive industrial use, protecting induction motors from overvoltage, overcurrent, under-speed, and overheating is essential. Voltage and current relays, timers, contractors, and other traditional protection techniques are mechanical devices. Both computer-based and PIC-based techniques have fewer mechanical components, although the former needs analog-to-digital conversion cards while the latter does not display the observed electrical parameters. In this work, a PLC based protection technique that does away with contractors, relays, and conversion cards is presented. It keeps an eye on system errors, motor voltages, currents, speed, and temperature while showing alerts on a computer screen. In comparison to conventional, computer, and PIC-based systems, experimental findings show that this PLC-based approach is more precise, efficient, and offers a safer and more visible environment.