Distance Protection Research Articles

Social Distance Violation Detection

This paper presents a strategy for social distancing location utilising deep learning to gauge the distance between individuals to decrease the effect of the Covid pandemic. This app was created to make individuals aware of keeping a protected distance with one another by assessing a video feed. The video outline from the camera is utilised as information, and the item identification model in view of the YOLOv3 calculation was utilised for pedestrian location. The distance between individuals can be estimated and any disregarding sets of individuals in the showcase will be shown with a red casing and red line. The proposed strategy was approved on a pre-recorded video of people on foot strolling in the city. The outcome shows that the proposed technique can decide the social separating measures between various individuals in the video. The created strategy can be additionally evolved as a recognition based application.

Monitored air pollutants from waste-to-energy facilities in China: Human health risk, and buffer distance assessment

China is progressively using incineration to manage municipal solid waste (MSW). However, the associated air pollution and health risks have received little attention. Furthermore, the current buffer protection may no longer significantly mitigate people's exposure to harmful air pollutants. Consequently, this study explores the emission characteristics of five monitored pollutants PM, SO2, NOx, CO, and HCl, as well as heavy metals generated by 510 incineration plants. The hazard index (HI) assessment included Cd, As, Cr, Ni, Pb, and Hg, whereas the cancer risk (CR) included Cd, As, Cr, and Ni. Our results show a decreasing trend in the total emissions of PM, SO2, and CO from 2015 to 2020. At 1 km downwind, the national average HI was 1.06, slightly above the recommended HI threshold (HI ≤ 1). In addition, the national average CR was beyond the safe level of 1 × 10−4 (CR = 5.69 × 10−3). The multicriteria decision tool, RAFSI, indicates 1.5 km as the best alternative buffer protection distance for an acceptable risk level. This finding suggests a potential reevaluation of the minimum buffer distance.

Investigation of using dynamic phasors for improving the speed of distance protection

The application of dynamic phasors (DPs) in overhead line protection was investigated. Equations to estimate the fault loop inductance and resistance were derived using the principles of DPs. A systematic amplitude comparator-based line distance protection scheme was developed using the equations derived to estimate the fault loop inductance and resistance. A least-squares-based DP extraction method that mitigates the effect of decaying dc components was used to extract the DPs and their derivatives from time-domain signals. The performance of the algorithm was investigated using a power system simulated in PSCAD/EMTDC. Testing under different fault scenarios with different fault locations, fault resistance, and fault inception angles showed that the proposed line distance protection scheme is capable of operating successfully for forward and reverse faults, short circuits and high impedance faults, evolving fault conditions, and under a wide range of source impedance ratios. The operating time of the proposed scheme was compared with the standard quadrilateral relay, and the results showed that the operating times of the proposed scheme are faster for close-in phase-to-ground faults but not significantly improved for phase-to-phase and three-phase faults compared to the standard quadrilateral distance relay.

Transmission Line Distance Protection Algorithm Based on Bayesian Inference

This paper presents a distance protection method based on estimating the resistances and inductances seen by the relay using a least-squares (LS) approach combined with the application of Bayesian inference (BI) to determine fault probabilities in the protected zone over time. The use of BI in the presented algorithm increases the security and reliability of the LS-based line protection approach, which, although fast, may yield impedance estimates with numerical inaccuracies and therefore configures a solution capable of detecting faults internal to the protected zone rapidly and dependably. The authors tested the proposed algorithm using data sets obtained from transmission line fault simulations performed in Alternative Transients Program (ATP), which considered noisy measurements, current transformer (CT) saturation, capacitive-coupling voltage transformer (CCVT) transients, switching onto fault, close-in faults, frequency variations, uncertainties in the line’s parameters, and power swings. Furthermore, the authors tested the presented method against measurements recorded by field protection equipment during seventy-nine actual fault events on four existing 500 [kV] lines. The results indicate that the proposed algorithm is a fast, secure, and reliable distance protection solution and that using BI to the LS-based distance protection approach increases security while maintaining fast fault detection.

Protection for 330 kV transmission line and recommendation for Nigerian transmission system: a review

The transmission line is an integral part of the electrical power system; however, a fault has a negative impact on the system, like blackout, power loss, financial losses, and socio-economic impact. This fault occurs due to ageing conductors, lightning stroke, switching surge and human interference. We reviewed the protection scheme implemented in the Nigerian transmission network, which has challenges relating to the environment's terrain and a long-distance transmission line of about 20,000 km. The different approach of fault classification, detection and location was analysed and critically summarised. This review paper proposes a hybrid Artificial Neural Network and distance protection scheme that can automatically identify, locate, isolate, predict, correct faults, and real-time monitor and control the entire network. It can also detect the shortest possible trip time of 0.02 s and 0.03 s of line current and fault losses, respectively, during fault to avert damage on the line. However, this method has its challenges, such as the volume of data generated from load flow analysis, training time, and the total distance covered by the network. However, these can be averted by segmenting the entire network for easy evaluation and monitoring to achieve set goals.

A feasibility study of using Manufacturing Message Specification report gateway model for IEC61850 inter-substation type-1 messaging over Wide Area Network

This paper presents a feasibility study of using TCP-based MMS report gateway model for transmitting type-1 messages over WAN. In IEC61850-90-5:2012, the Standard suggests to use UDP-based R-GOOSE for exchanging the type-1 messages, i.e. trip signals and other fast messages defined in the Standard, over WAN. However, due to the cyclic retransmission inherited from GOOSE, R-GOOSE messages are repeatedly sent to the network and thus pose unnecessary traffic to the WAN. With the proposed model, unnecessary re-transmissions can be eliminated. It can preserve bandwidth for more IEDs being imposed on the existing smart grid. To achieve this task, two IEC61850-based gateways for translating GOOSE Messages to and from the MMS report over WAN have been modeled and implemented. The authors then make use of an HLA-complied co-simulation platform to simulate a distance protection scenario through the gateways to investigate the communication latency with different links speed and utilization rate of WAN. Simulated results show that the proposed MMS report gateway model works well for different WAN link speed from DS3 to 1000BaseX. Simulation results further indicate that introducing QoS control to the WAN routers is an effective method to warrant the latency for satisfying the IEC61850 standard requirement. The result from this feasibility study reveals that the TCP-based MMS report gateway model indeed can be used as an extended feature for transmitting type-1 messages between substations over WAN. Furthermore, this method is suitable for connecting more IEC61850-based DER to the existing smart grid involving WAN.

Evaluation of HVDC system's impact and quantification of synchronous compensation for distance protection

This paper presents a comprehensive evaluation of the HVDC system's impact on distance protection via systematic and realistic experimental tests, along with theoretical analysis of the root causes of the identified compromised protection performance. A methodology for quantifying the impact of Synchronous Compensation (SC) in supporting the distance protection operation is also established. In this work, the performance of two widely used physical distance protection relays have been evaluated using a realistic Hardware'In'the'Loop (HIL) testing environment, where a total of 480 cases have been tested under a wide range of system scenarios. Representative cases with compromised protection performance are selected, where issues of under/over'reach, faulted phase selection and impedance measurement are identified and analysed. Furthermore, a method for quantifying the required SC level to address the under/over'reach issues resulting from HVDC systems is presented. The method establishes the relationship between the angle difference of the two'end fault current infeeds of the protected line and the SC level. Based on this relationship, the required SC capacity to constrain the angle difference within a targeted limit can be estimated, which offers a useful tool for system operators to appropriately size the SC's capacity with additional valuable insights from the distance protection perspective.

Accident type analysis and consequence simulation of LNG terminals equipment and facilities

A new round of energy change, energy clean and low carbon development become an inevitable trend. In the adjustment of energy structure, natural gas becomes the strongest growth carrier and LNG reserve peak regulation is of great significance. Building liquefied natural gas receiving center to secure domestic natural gas supply has become the main target, task and key work. Through the simulation of various equipment and facilities in the LNG terminal under different leakage scenarios, the accident scenarios are selected according to the protection distance criteria, the simulation of steam diffusion, pool fire, jet fire and explosion is carried out, and the influence range of consequences is obtained. The thesis provides a theoretical basis for the quantitative risk assessment for LNG terminal accident and the prediction of emergencies, having positive guiding significance for risk management and emergency disposal of new or operating LNG terminals.

Distance relaying of Untransposed parallel transmission lines in case of phase-phase inter-circuit faults

• Untransposed parallel transmission lines are targeted for distance relaying. • Phase-phase inter-circuit faults are addressed in the distance relaying. • The ADALINE is developed for an accurate online estimation of the fault distance. • The proposed approach achieves fast fault tripping and an accurate fault location. • It tolerates noisy conditions and properly handles variable fault arc resistance. Distance relays at both circuits of the parallel transmission lines would miscalculate the right fault impedance during inter-circuit faults. This paper deals with the distance relaying of untransposed parallel lines in case of phase-phase inter-circuit faults. It is a challenging case compared to that of transposed lines due to the mutual coupling between all six phases of the line circuits. Considering a phase-phase inter-circuit fault with the fault arc resistance, the line circuit model is analyzed on a time-domain basis. Consequently, a mathematical equation with a linear combination of specified functions is derived. This provides a splendid opportunity to establish an ADAptive LINEar combiner (ADALINE) consistent with the equation derived. The ADALINE with its simple structure gives a fast and accurate online estimation of the fault distance, employing single-end measurements during the inter-circuit faults. Hence, achieving the fault location along with the distance protection is also made possible. The proposed approach is readily implementable without being dependent on the system configuration. It operates robustly against the dynamic fault arc resistance and tolerates the noise contamination. The simulations in PSCAD/EMTDC provide extensive sensitivity analyses validating the proposed approach performance, in respect of both the accuracy and swiftness, for various fault conditions.

An enhanced distance protection algorithm based on characteristics-travelling waves measured from the current for HVDC Lines

It is a vital challenge to perfectly and reliably position high impedance faults and remote end faults in high-voltage direct current (HVDC) transmission lines. Also, distance protection systems are very vulnerable to maloperation under power swing situations and noise interference. These challenges are essential for system stability. This paper succeeded in these challenges with high accuracy, reliability, and stability and without delay in protection startup for single pole-to-ground faults and pole-to-pole faults during ultra-high-speed. The paper presents new employment for the 2nd order of the sequential overlapping difference (SOD) tool to capture transient component characteristics of both terminals of the DC-TL, calculate the fault distance, and identify the faulted pole. Also, it presents novel employment of external disturbances to estimate the fault location. This employment protects the proposed technique from the errors resulting from the mistakes in knowing the transmission line parameters data. The paper studies a bipolar-HVDC-TL system established in (ATP/EMTP). Besides, the proposed algorithm is valid for both single-pole and two-pole operation modes. Also, it suggested an amplification process to magnify the stability margin between normal and abnormal operations. And, it verifies the decision by employing more than information. In addition, the distributed capacitance does not affect it.

Compensating the combined impact of hexagonal phase-shifting transformer and fault resistance on the distance protection

This paper studies the performance of the distance relays for transmission lines equipped with hexagonal phase-shifting transformers (PSTs). PSTs can effectively control the power flow in the transmission lines. However, they alter the operation of the distance protection elements. The influence becomes significant when the fault occurs through a resistance. In this paper, the combined effect of the PST and the fault resistance on the operation of the ground and phase distance relays is considered. The analysis accounts for the effect of the PST not only on near distance relays but also on relays protecting an adjacent line. System analysis is carried out and a compensation technique is derived based on the location of the fault concerning the installation location of the PST. An operation logic is proposed to coordinate the operation of different proposed compensated protection elements. This operation logic helps to select the proper method ensuring the reliability of the protection system. The proposed protection scheme uses the voltage and/or current measurements at the relay point in addition to the transferred PST tap position. Therefore, synchronized voltage and current measurements from different locations are not required. The simulation study conducted with MATLAB/Simulink shows the success of the proposed ground and phase distance elements to account for the combined effect of the PST and the fault resistance.

“Distance” in intellectual property protection and MNEs’ foreign subsidiary innovation performance

AbstractDrawing on the institution‐based view of intellectual property (IP) rights, we argue that “distance” in IP protection strength of MNEs’ home and host countries reduces the ability of MNEs to innovate at foreign subsidiary locations. We contend that this logic applies in both directions—i.e., (1) downward direction, when MNEs originating from stronger IP protection regimes innovate in weaker IP protection regimes, and (2) upward direction, when MNEs originating from weaker IP protection regimes innovate in stronger IP protection regimes. Furthermore, we suggest that the negative effect of IP protection distance on foreign subsidiary innovation performance will be moderated by internal (strategic) and external (institutional) conditions, such as the subsidiary experience, subsidiary ownership type (full vs. partial), cultural distance and the extent of scientific labor in the host country. We test the above relationships using a very large panel data set consisting of MNE subsidiary‐level data in the manufacturing industry for 15,246 subsidiaries of 11,284 parent firms, representing 47 home countries and 31 host countries and covering a total of 91,347 observations for the period 2005–2013. Our findings show that (1) the adverse effect of IP protection distance on subsidiary innovation performance applies in both directions; (2) the effect is more intense in case of the downward direction; and (3) the moderating effects vary depending on the direction of IP protection distance.

Parental attitudes in perception of fathers of deaf children

The paper is of an empirical character. The main objective of the study was to diagnose declared attitudes of fathers towards deaf children. The study made use of the Parental Attitude Research Instrument (PARI) by E. Schaefer and L. Bell. The base group comprised 50 fathers of deaf children (FDC). Additionally, a group of 58 randomly selected fathers having only hearing children were examined (control group – FHC). The analysis of results of this study takes into account first general attitudes of the fathers, i.e. proper emotional contact, the attitude of excessive distance and excessive concentration or protection, as well as attitudes towards family and educational roles; thereafter, the subscale scores were averaged to diagnose the intensity of each particular attitude. As a result of the study, it was established that the presence of a deaf child in the family affects the shaping of specific parental attitudes. The age and education of fathers of deaf children were the variables that also affected the shaping of parental attitudes. In summary, the conclusions for pedagogical practice will be discussed.

A Moving Window Numerical Distance Protection Based on Flat-Top Signal Windowing

A Moving Window Numerical Distance Protection Based on Flat-Top Signal Windowing

Superimposed components-based distance protection of lines emanating from DFIG-based wind farms

Type-III wind turbines with doubly fed induction generators (DFIGs) are generally equipped with crowbar circuits in practice to realize the low voltage ride-through (LVRT) during the fault period. Under this situation, DFIGs exhibit significantly different fault behavior by contrast with synchronous generators (SGs). This difference poses inevitable challenges to the existing distance protections that are normally designed based on SGs’ fault signature. In this paper, some easily overlooked issues regarding the superimposed components-based distance protection (SCBDP) when applied in lines emanating from DFIG-based wind farms (WFs) are revealed. It is shown that the unified phase angle property in the additional fault network may be jeopardized in the presence of DFIG-based WFs, thereby resulting in the high probability of failure under the in-zone fault conditions or undesirable operation under the out-of-zone fault conditions for the conventional SCBDP. To address these problems, based on the “phase angle congruency” idea, this paper proposes an improved SCBDP to mitigate the adverse impact of the crowbar-activated DFIGs. By adaptively regulating the phase angle of operating voltage, the improved SCBDP can work properly independent from the fault types and the sizes of crowbar resistance. Also, compared with conventional SCBDP, the improved SCBDP shows higher sensitivity and reliability while inheriting its strong tolerance capability against fault resistance. Extensive simulation results under different fault conditions show the expected performance of the improved SCBDP.

Distance Protection of Transmission Lines in Presence of Inverter-Based Resources: A New Earth Fault Detection Scheme During Asymmetrical Power Swings

Although it is commonly assumed that power swing is symmetrical and will have identical effects on all three-phase voltages and currents, there is another type of power swing, which is asymmetrical and mainly occurs during single-pole tripping (SPT), the impact of which on power systems integrated with the inverter-based resources (IBRs) has not been investigated so far. Since the likelihood of the occurrence of asymmetrical power swing is increasing in today's heavily loaded transmission lines, this article investigates the impact of IBR integration on the performance of distance protection during single-pole tripping. Furthermore, a new scheme is proposed to detect earth faults that occur during asymmetrical power swings to enhance the performance of power swing blocking functions. To do so, the superimposed component of the zero-sequence current during SPT is extracted. Then, the moving average window is used to calculate the average of both zero-sequence current and its superimposed component. Furthermore, to enhance the security of the proposed scheme, a new technique based on the phase angle shift between the three-phase currents is devised to detect the asymmetrical power swing conditions. This article shows that as the penetration level of IBRs increases, the standard reclosing dead-time needs to be revisited otherwise it can create an unstable power swing condition, even during SPT. Moreover, this article shows that the proposed earth fault detection scheme can efficiently detect all single-line-to-ground faults occurring during SPT.

A simplified evaluation of protection distance in areal spectrum sharing

A simplified evaluation of protection distance in areal spectrum sharing

Sharing Studies between 5G IoT Networks and Fixed Service in the 6425-7125 MHz Band with Monte Carlo Simulation Analysis.

This work presents sharing studies between 5G networks and point-to-point fixed service in the 6425–7125 MHz band. In this research, we provide simulations of interference from 5G downlink and uplink to fixed service in the frequency band 6425–7125 MHz. We evaluated several scenarios of interference, which include cross-border scenarios, as well as scenarios of interference within the borders of one administration. The obtained results of this work are presented as protection distance and frequency offsets that are required in order to achieve compatibility between 5G and FS in the 6425–7125 MHz band. The spectrum engineering techniques presented in this research can help different companies and regulatory administrations in their spectrum management and frequency regulation activities and seriously improve the efficiency of implementation for 5G technologies.

Hybrid of Angular and Distance Protection for Coexistence of 5G Base Stations and Satellite Earth Stations

In this study, we investigated the coexistence of the 5G communication network with a fixed-satellite service (FSS) in the 3.5 GHz and 26 GHz frequency bands. We analyzed an angular protection scheme for the FSS Earth station (ES) and 5G base stations (BSs). In addition, we defined the fixed BS-ES relative location, relative distance, and angular changes. The angular protection was integrated into the exclusion and restricted zones proposed by the distance protection scheme for simulation analysis to develop a transmit power control scheme based on the Citizens Broadband Radio Service. Its performances were extensively analyzed through simulations. The proposed scheme was evaluated in practical scenarios: rural macrocells, urban macrocells, and urban microcells, as defined by the 3rd Generation Partnership Project (3GPP). The influence of antenna type was also researched, and BSs with 4 × 4, 8 × 8 and 16 × 16 antenna arrays, as specified by 3GPP, were considered for 5G networks. Finally, the results prove that the angular protection solution can solve the coexistence of the 5G system and the FSS. In addition, when angular protection and distance protection are used simultaneously, the coexistence effect of the two systems can be strengthened. Moreover, this work provides a quantitative perception for selecting system parameters, including an interference margin for the different scenarios and antenna types, the exclusion size, and the reduction area.

Study on structural parameters optimization of a new inclined inserting and hole plate-type combined sand barrier

In this paper, a new double-row sand barrier combined inclined inserting-type and hole plate-type sand barrier is proposed. Based on the Euler two-fluid unsteady model, the protection effect and flow field characteristics of the new sand barrier with different spacings are numerically simulated. The results show that the new sand barrier proposed in this paper has better wind resistance than the double-row hole plate-type sand barrier. The new sand barrier with spacing of 1H provides the longest effective protection distance and better wind protection. And the large spacing increases the air flow across the second-row hole plate-type sand barrier, which will reduce the protective effect of the new combined sand barrier. In addition, the windproof efficiency of the first-row inclined inserting-type sand barrier is 50%, and the windproof efficiency of the second-row hole plate-type sand barrier is 96%. It can be seen that the windproof efficiency of the double-row sand barrier is not twice that of the single-row sand barrier. Taking into account the strong wind and sand environment in Northwest China, the sand resistance effect of the new sand barrier is studied in this paper. The results show that the new sand barrier has better sand resistance effect, so that the sand is mainly deposited in the middle of the new double-row sand barrier and the windward side of the first-row sand barrier, while less deposited in the leeward side of the second-row sand barrier. It indicates that the first row of sand barrier plays the main sand resistance role.