Protective Relay Settings Research Articles

Enhancing Grid Resiliency in High Fire or Flood Risk Areas: Integrating Protective Relay Settings, Broken Conductor Detection, and Grid Hardening for Climate-Induced Event Preparedness

Enhancing Grid Resiliency in High Fire or Flood Risk Areas: Integrating Protective Relay Settings, Broken Conductor Detection, and Grid Hardening for Climate-Induced Event Preparedness

Neural Network-Based Aggregated Equivalent Modeling of Distributed Photovoltaic External Characteristics of Faults

Distributed power networks have a large number of photovoltaic power sources. The bidirection of power flow, different transient control strategies, and installation locations make the transient characteristics highly complex and unpredictable. The vast network of the distribution system makes it almost impossible to predict the electrical quantities of each branch. Reasonable aggregation modeling of the distribution network can greatly simplify the network topology, facilitating transient control and the setting of relay protection settings. An aggregated equivalent modeling method based on the LSTM neural network for distributed PV fault external characteristics is proposed. This method equates the complex distribution network to a highly nonlinear but controllable current source. The method can output the I–V curves of equivalent PV system parallel points under any output power and is able to predict the fault characteristics of the equivalent system after a voltage drop at the parallel point. Compared to traditional mechanistic modeling, this method does not require specific modeling of complex physical systems and is able to accurately map the strong nonlinear inputs and outputs of distribution networks. The established LSTM model first uses a one-dimensional convolutional layer for feature extraction of the PV power coefficients (input), and then two hidden layers are utilized to process the sequence data; the vectors are mapped into a sequence of external characteristic curves (output) in a fully connected layer. A typical distribution network is built based on the traditional PV power model, and a large number of different output combinations are selected for simulation to provide an effective training set and validation set data for LSTM model training. By using the training set data, the weights and offset coefficients of each layer of the LSTM are continuously optimized until the model with the smallest overall error is obtained, which is the optimal model. Finally, the optimal model is utilized to establish an equivalent distribution network system, different degrees of voltage drops are set up at the grid-connected points, the fault characteristics are compared with those of the complete model, and the simulation results can prove the reliability and practicality of the proposed method.

Review on Coordination of Time Overcurrent Relays in Electrical Distribution Network

Integration of distributed generators in micro grid causes bidirectional current flow as a result of the need for readjustment of the setting of the overcurrent protective relays in the electrical network. Adaptive coordination is one of the solutions that adjust the setting of protective relays according to the dynamics of the distribution network. Various algorithms had been reported on the adaptive coordination of time overcurrent relays. This paper reports a survey about the coordination of time overcurrent relays in micro grid electrical distribution network. The review found that there is limited research on distributed control rules of the multi agent coordination of protection relays. Furthermore, it was found that the trend of coordination algorithms focused on the nature inspired algorithms.

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.

Power Compatibility of Induction Motors in Industrial Grids Containing Synchronous Generators

Starting an induction motor causes voltage sag in the industrial grid that may disturb the operation of grid equipment. Direct-on-line starting is the simplest and most cost-effective method for starting induction motors, but also the most problematic. Large industries often use internal power plants with synchronous generators and starting powerful motors may impact the generator operations. The synchronous generators could be operated with the automatic or manual mode of voltage control. As the operation experience proves, the generator voltage control mode has a significant impact on the transient behaviours in the industrial power grid when starting a large induction motor. This article presents a case study of the synchronous generator tripping within a true medium-voltage industrial grid during the direct-on-line starting of a large induction motor driving the feed water pump. An analysis of the generator protection logs after the tripping showed that the synchronous generator was controlled in manual mode and its protection relay settings were exceeded. The transients initiated by induction motor starts were studied for possible configurations and operating conditions of the grid using a model developed on the Matlab/Simulink Software platform. The simulations have shown that concern about starting large motors in industrial grids containing internal synchronous generators needs to be solved considering the grid configurations and the coordination of generator protection and control devices.

Research and application of relay protection setting calculation for SFC system of pumped storage power station

Pumped storage is a key way to meet the regulatory needs of the power system. Currently, SFC starting has become the main starting method for large pumped storage power plants. This article introduces the typical structure and operation principle of SFC in pumped storage power plants. Based on existing guidelines, the relay protection configuration and setting principles of the SFC system in pumped storage power plants are elaborated. Starting from engineering practice, a relay protection setting calculation scheme for SFC input and output transformers is proposed and put into operation on site, ensuring the reliable and stable operation of the SFC system in pumped storage power plants.

A multi-objective optimisation of relay protection settings in distribution networks based on improved grey wolf algorithm

A multi-objective optimisation of relay protection settings in distribution networks based on improved grey wolf algorithm

A multi-objective optimisation of relay protection settings in distribution networks based on improved grey wolf algorithm

A multi-objective optimisation of relay protection settings in distribution networks based on improved grey wolf algorithm

Protection Relay Setting based on Overcurrent Phenomena in Commercial Building

Nowadays, every single distribution system needs to install an appropriate relay to keep the system safe. The operational and commonly recommended relay for distribution systems is the overcurrent (OC) relay. Throughout the distribution system, the protective relay is one of the methods that can detect and protect the location according to its observation from any fault from abnormal activity. Note that time coordination between the protective equipment relay needs to be a minimum of time interruption to prevent faults occurs. The ideal setting for all coordination protection relays is necessary to protect the device against electrical failure and interference. This paper analyzes the real results data collected for the selected commercial building of an OC relay implemented in a distribution board for high voltage and low voltage downward at a commercial building. All the parameters need to be clarified first before testing has been made and measurement is carried out using the MICROTEST 860 set. Based on the analysis, it proves that according to the IEC Standard of 0.10-time multiplier Setting (TMS) is practical to be used to obtain the operation time in seconds for the current curve set. Other than that, the results show that the normal inverse curve from manual calculation results is more accurate compared to the service setting (SS) made based on the incoming setting in a real commercial building. The case study for OC relay setting is related between current injection and time-tripping, which complies with the IEC 60255-3 standard using its formula. This method was applied to determine the characteristics of the curve. Hence, this research successfully determined the proper methods for the OC relay setting for the power distribution system. Besides, the feasibility and efficiency of OC relay data transmission are tested and checked successfully to implement the measurement method in the relay coordination study.

Overcurrent and ground fault relay protection settings at tranformator-1 150kV/20kV Braga substation

The occurrence of a malfunction at the substation results in power outages and losses in the electrical energy distribution system to consumers. Many tests are carried out to see the performance of the protection system, including the parameters of the over current relay (OCR) and ground fault relay (GFR) in the electrical energy distribution system. This research aims to analyze OCR and GFR values, analyze OCR setting, drop-off, and pick-up values, and analyze OCR time characteristics using DigSilent Power Factory 15.1 software based on existing equipment specification data at the Braga substation. The results show an OCR accuracy level of around 94% on the 20 kV and 150 kV sides. Meanwhile, 92.39% on the 20 kV GFR side and 94.87% on the 150 kV side. The setting value for the pick-up current is 0.92 A on the 20 kV side of the GFR and the drop-off current is 0.85 A on the 150 kV side with a pick-up current of 0.39 A and a drop-up current of 0.37 A. Setting a value on the 20kV side is greater than on the 150 kV side due to the difference in current transformer ratio values. The simulation results show that the OCR and GFR characteristic curves on both sides meet the criteria for a protection system with good performance.

Relay Protection Setting Calculation of Power Transformer Based on ETAP

The conventional relay protection setting calculation method considers the internal interference of the transformer and obtains the setting value quickly, which leads to large harmonic interference of the transformer and affects the secondary setting calculation results. Therefore, the setting calculation method of the power transformer relay protection based on the Electrical Transient Analysis Program (ETAP) is designed. The harmonic transfer characteristics of the power transformer are extracted, and the harmonic interference of the power transformer is proposed. Then the ETAP software is adopted to establish the calculation principle of the power transformer relay protection setting and improve the calculation accuracy of the secondary setting. Through comparative experiments, it is verified that the second fixed value of the algorithm is close to the actual fixed value and can be applied to real life.

Multi-objective Optimization of Relay Protection Setting Based on MOAHA Algorithm

With the expansion of the power grid scale, more and more relay protection devices exist in the power system, and the optimization of node protection setting values has also begun to receive attention. Conventional genetic algorithm is mainly used in the current multi-objective optimization solution of relay protection fixed value, and its multi-objective optimization procedure is relatively complicated, resulting in low optimization solution efficiency. Therefore, applying the multi-objective artificial hummingbird algorithm (MOAHA) to the optimization process is proposed to obtain a new fixed-value multi-objective optimization method for relay protection. According to the set value requirements of the relay protection, a multi-objective optimization model of the set value of the relay protection is established, and the constraints are determined. Regarding the grid vulnerability coefficient, calculate the weighting factor corresponding to each constraint condition. Then, the multi-objective artificial hummingbird algorithm is applied to design a simple multi-objective optimization mode, including two stages of self-search and guided search to obtain fixed-value optimization results. The results of the example analysis show that the proposed optimization method only needs 20 iterations to output the optimal solution, and the average time spent to obtain the optimal solution is 17.6s. It can play a prominent role in the global optimization and tuning of relay protection in large power systems.

Performance Enhancement of Overcurrent Relay in Distribution Systems by Extending Stability Limits and Considering High-Impedance-Fault

The electric power distribution scheme of a power plant should be analysed to prevent the occurrence of the slightest fault current and improve system reliability during the power production process. Protection relay settings installed on the electricity network should calculate the condition of the generator with various types of fault currents. Installation of relays that do not consider transient stability leads to generator instability even though the fault is eliminated. Therefore, it is necessary to calculate the stability limit while setting the overcurrent relay. However, a failure in the relay setting can occur if the inverse relay cannot protect against a high-impedance fault. Therefore, a method was proposed to determine the stability limit based on a short circuit without impedance and with an applied impedance, and the application of the method was demonstrated through existing settings and resetting conditions in simulation software. A modification relay setting prevented the loss of synchronisation of the generator during fault occurrence. The working time operation was integrated with the definite and inverse overcurrent relays in ANSI 50, 51, standard operating time of the relay, and critical clearing time of the generator. The type of fault used was a three-phase fault, with and without high-impedance. The calculation results demonstrated that this concept can be used to protect lines and generators during a short circuit current.

Analysis of Akangba Transmission substation protection system

The challenges of the Nigeria power system have deprived the yearning electricity consumer access to stable power supply. Apart from the incessant load shedding due to inadequate power generation capacities, poor power system protection design, lack of constant protection system review after several changes to the power network is one of the contributing factors for unstable power system and unplanned outages. The network engineers must devise method of reviewing the protection settings as changes are made to power system components. This motivates the adoption of power system symmetrical fault analysis model presented herein. The model was applied to Akangba Transmission substation using the network planning software (NEPLAN software). The results show the fault current flowing through every part of the network. The effect of network expansion, switching Scenarios /Component changes on the fault current and protection scheme was also verified. Protection engineers must therefore take note of changes in the power network configuration when planning protection coordination and relay setting. The method is interesting and can be used as a template for reviewing protection scheme when changes are made on the power network. This will ensure better power protection management, enhance stable power supply and reduce damage to expensive power components.

Повышение устойчивости заводских электростанций при отделении от энергосистемы в результате внезапного короткого замыкания, сопровождающегося небалансом мощностей

Разработан алгоритм для использования оперативно-диспетчерским персоналом, позволяющий выявить причину нарушения устойчивости заводских электростанций. Предложены рекомендации по корректировке присоединяемой активной и реактивной мощности нагрузки с учетом конечных значений напряжения и частоты в энергосистеме, а также уставок срабатывания релейной защиты. Использование алгоритма позволит повысить эффективность управления аварийными режимами заводских электростанций при отделении от энергосистемы и сократить время простоев от недоотпуска электроэнергии с учетом перспективно изменяемых мощностей.

Short-circuit model of the DFIG considering coordinated control strategy of grid- and rotor-side converters

The short-circuit current calculation is of vital importance for the power system. With a high proportion of new energy sources, the setting of relay protection and the selection of electrical equipment have been severely degraded. An accurate short-circuit current calculation model of new energy source is necessary for the short-circuit calculation of power grid with new energy sources. However, due to the DFIG’s control system is a ”black box”, and an accurate fault characteristics and short-circuit current calculation models of DFIG is difficult to obtained. Currently, for the fault current of the DFIG, lots of research works is carried out under symmetrical fault or the crowbar protection is activated condition. However, under crowbar protection is not activated and unsymmetrical fault condition, there are no unified short-circuit calculation models of DFIG. In this paper, the transient process of DFIG under those condition is analyzed, and mathematical expressions are derived. Moreover, the comprehensive and unified short-circuit calculation models of DFIG have established under different low voltage ride through control conditions. The influence of GSC and slip rate of DFIGs can be considered. The test results show that the LVRT control strategies, the GSC and slip have an important influence on the DFIG’s short-circuit calculation model. The quantitative research results are of important significance for relay protection setting calculation, grid operation and control, and the selection of electrical equipment of power grid with DFIGs.

A Detailed Testing Procedure of Numerical Differential Protection Relay for EHV Auto Transformer

In power systems, the programmable numerical differential relays are widely used for the protection of generators, bus bars, transformers, shunt reactors, and transmission lines. Retrofitting of relays is the need of the hour because lack of proper testing techniques and misunderstanding of vital procedures may result in under performance of the overall protection system. Lack of relay’s proper testing provokes an unpredictability in its behavior, that may prompt tripping of a healthy power system. Therefore, the main contribution of the paper is to prepare a step-by-step comprehensive procedural guideline for practical implementation of relay testing procedures and a detailed insight analysis of relay’s settings for the protection of an Extra High Voltage (EHV) auto transformer. The experimental results are scrutinized to document a detailed theoretical and technical analysis. Moreover, the paper also covers shortcomings of existing literature by documenting specialized literature that covers all aspects of protection relays, i.e., from basics of electromechanical domain to the technicalities of the numerical differential relay covering its detailed testing from different reputed manufacturers. A secondary injection relay test set is used for detailed testing of differential relay under test, and the S1 Agile software is used for protection relay settings, configuration modification, and detailed analysis.

Setting and Testing of the Out-of-Step Protection at Mongolian Transmission System

Modern distance relays have integrated numerous protection functions, including power-swing blocking and out-of-step or pole-slip tripping functions. The main purpose of the power-swing blocking function is to differentiate faults from power swings and block distance or other relay elements from operating during stable or unstable power swings. Most power-swing blocking elements are based on traditional methods that monitor the positive sequence impedance rate. The required settings for the power-swing blocking elements could be difficult to calculate in many applications, particularly those where fast swings can be expected. For these cases, extensive stability studies are necessary to determine the fastest rate of possible power swings. This paper presents a detailed step-by-step method for settings calculation of out-of-step (OOS) protection, both blocking and tripping functions considering a generic two-source system. Then the method is applied to define the protection relay settings installed at the interconnection between the Russian and Mongolian power systems, as it is crucial to feed the demand-rich Mongolian power system. In this paper, a specific impedance method is used for defining the OOS protection settings. This paper innovates by testing the settings using the recordings of the major events of 15 September 2018 in two approaches: hybrid co-simulation and cyber-physical. Both tests have demonstrated the appropriate performance of the proposed settings and proving the proposed methodology works appropriately.

The Calculation Method of Ice Melting Schemes’ Relay Protection Settings and Clarification of the Ice Depositions Control Method on Steel Lightning Protection Wires

The method of current values calculation of overcurrent and undercurrent relay protections included in the complex of relay protection of ice melting schemes by alternating current on steel lightning protection wires of overhead transmission lines is analysed. A comparison with the generally accepted method, called the element-by-element method, is made. The element-by-element method is based on using the parameters of all the elements included in the ice melting scheme to calculate the maximum and minimum melting currents, from which the corresponding protections must be adjusted. These parameters have a significant variation, especially the active and internal reactive resistances of steel lightning protection wires at alternating current, what increases the calculation error. The proposed method, called the recalculation method, is based on the use of the trial melting mode parameters, carried out annually in the autumn season on lightning protection wires, with a duration up to 2 minutes. In difference to the usual practice, the trial melting has to be carried out 2 times with different currents. According to the parameters of the mode the settings of relay protection are recalculated using the given methods. The methodological and additional errors of the new method are estimated, that shows proposed method advantage. The parameters of the trial melting mode can be used to specify the methodology for remote control of ice formation (the length of the ice formation zone).

Improvement of Midle Voltage Network Protection System at Kualanamu International Airport

The electricity grid protection system at Kualanamu International Airport is urgently needed. The purpose of protection in addition to maintaining the reliability and stability of the electric power system also functions to detect disturbances, prevent damage to equipment (equipment & networks), protect humans and minimize outages in the event of a system disturbance. flight safety operations, services to passengers, operations, and equipment work at Kualanamu Airport. Safety or protection settings are based on the characteristics of the protection installed in the distribution system, which greatly affects working time, from the protection security area if there is a failure in the main protection. determine the setting of the overcurrent relay against overcurrent disturbances that may occur due to short circuit faults. To simplify the calculation of the disturbance analysis, it is simulated using the Electric Transient and Analysis Program (ETAP) Power Station12.6 software. The relay protection that is used and set is the overcurrent relay at the Kualanamu Airport Medium Voltage Network Sub Station. This relay functions to protect fault currents against ground-phase, ground-phase, ground-phase, and 3-phase. The protection relay setting refers to the provisions in force at PLN, namely for the interruption time of the 20 kV network disturbance at the substation from the time of a disturbance to the extinction of the electric arc by the opening of the power circuit breaker (PMT) the feeder is: less than or equal to 400 milliseconds and for ground-phase short circuit faults NGR12 maximum disconnection time of 500 milliseconds, NGR40 maximum disconnection time of 1000 milliseconds.