Distance Protection Research Articles

NEOLOGISMS THAT APPEARED IN THE VOCABULARY OF KAZAKHSTANIS DURING THE CORONAVIRUS PANDEMIC

All languages on the planet are responsible for various social situations and phenomena that occur in society. The Kazakh language is also constantly developing, replenishing, and changing. Every day, new words appear in his vocabulary, become obsolete, some of them are out of Use, and some of them change in meaning and are updated again. The recent pandemic and the current epidemiological situation in the country have also affected the language. The covid-19 coronavirus infection pandemic and restrictive measures have brought significant changes to the public life of the whole world, including Kazakhstan, as well as gave an impetus to the formation of new names through the internal resources of the language, the productivity of some wordforming tools, the rapid flow of language processes. In fact, Corona has added new terms to the vocabulary of all languages of the world. Along with the pandemic, many words such as social immunity, masks, vaccinations, distance protection, covid, etc.have entered the vocabulary of Kazakhstanis. The article analyzes neologisms related to the coronavirus pandemic that have appeared in the Kazakh language or whose meaning has been updated. Lexical innovations of the coronavirus era, such as coronaviruses, coronaviruses, and coronaviruses, appeared in the language in 2020 and in a short period of time entered the common language and took a place among the words that form a combination with a high frequency of use.

NEOLOGISMS THAT APPEARED IN THE VOCABULARY OF KAZAKHSTANIS DURING THE CORONAVIRUS PANDEMIC

All languages on the planet are responsible for various social situations and phenomena that occur in society. The Kazakh language is also constantly developing, replenishing, and changing. Every day, new words appear in his vocabulary, become obsolete, some of them are out of Use, and some of them change in meaning and are updated again. The recent pandemic and the current epidemiological situation in the country have also affected the language. The covid-19 coronavirus infection pandemic and restrictive measures have brought significant changes to the public life of the whole world, including Kazakhstan, as well as gave an impetus to the formation of new names through the internal resources of the language, the productivity of some wordforming tools, the rapid flow of language processes. In fact, Corona has added new terms to the vocabulary of all languages of the world. Along with the pandemic, many words such as social immunity, masks, vaccinations, distance protection, covid, etc.have entered the vocabulary of Kazakhstanis. The article analyzes neologisms related to the coronavirus pandemic that have appeared in the Kazakh language or whose meaning has been updated. Lexical innovations of the coronavirus era, such as coronaviruses, coronaviruses, and coronaviruses, appeared in the language in 2020 and in a short period of time entered the common language and took a place among the words that form a combination with a high frequency of use.

A novel distance protection for MMC-HVDC lines based on the equivalent capacitance voltage

The present protection configuration for MMC-HVDC transmission line is not perfect enough due to poor reliability and insufficient protection types. Some works have been done on distance protection methods for DC lines. However, they encounter the problems of discriminating the zero-voltage fault or dependency on simulation. To overcome the problems above, this paper proposes a novel distance protection principle for MMC-HVDC lines based on the equivalent capacitance voltage (ECV). It is proved that the ECV of MMC will keep its polarity unchanged within a short period after the DC fault. And a further fault characteristic analysis indicates that the compensating voltage of the DC line has opposite polarity with ECV under the internal fault while has the same polarity under the external fault. Thus, the faults can be discriminated based on the polarity of compensating voltage during the short period after fault occurrence. Comprehensive simulation results have validated the effectiveness and strong robustness of the new method. The proposed distance protection stands out for its clear setting criterion, powerful anti-noise ability, independency of boundary and accurate response under the zero-voltage fault. It can offer a duplication and supplement to the traveling-wave protection.

Taylor series based protection starting element for STATCOM compensated transmission line

• Non-unit protection of STATCOM-compensated lines irrespective of compensation mode and level. • Taylor series based detection index using current signal to detect faults. • Accurate identification and discrimination of fault and non-fault events. • Adaptive threshold technique immune to power system structure. • The executional burden time is near about 5 ms. In the presence of nonlinear response created by power electronics-based compensators, reliable fault detection and classification by distance protection relays is a major concern. The static synchronous compensator (STATCOM) has dynamic characteristics that causes stability and protection issues. A Taylor Series-based strategy is proposed for addressing this issue. A detection index computed using Taylor Series and adaptive thresholding technique is employed such that unerring fault detection is achieved wherein faulty phases of a shunt compensated transmission line are well pointed out. Various fault and non-fault cases considering critical power system conditions are analysed for power systems with varying configurations modelled using EMTDC/PSCAD. A comparison of the current detection method to recently proposed techniques reveals the benefits and feasibility of the presented detection strategy, which has been proved to be accurate and efficient.

An Efficient Reliability-Based Approach for Evaluating Safe Scaled Distance of Steel Columns under Dynamic Blast Loads

Damage to building load-bearing members (especially columns) under explosions and impact are critical issues for structures, given that they may cause a progressive collapse and remarkably increase the number of potential victims. One of the best ways to deal with this issue is to provide values of safe protective distance (SPD) for the structural members to verify, so that the amount of damage (probability of exceedance low damage) cannot exceed a specified target. Such an approach takes the form of the so-called safe scaled distance (SSD), which can be calculated for general structural members but requires dedicated and expensive studies. This paper presents an improved calculation method, based on structural reliability analysis, to evaluate the minimum SSD for steel columns under dynamic blast loads. An explicit finite element (FE) approach is used with the Monte Carlo simulation (MCS) method to obtain the SSD, as a result of damage probability. The uncertainties associated with blast and material properties are considered using statistical distributions. A parametric study is thus carried out to obtain curves of probability of low damage for a range of H-shaped steel columns with different size and boundaries. Finally, SSD values are detected and used as an extensive databank to propose a practical empirical formulation for evaluating the SSD of blast loaded steel columns with good level of accuracy and high calculation efficiency.

A novel setting-free current frequency based symmetrical fault detection method in the out-of-step oscillation process especial for the 180 degree situation

Accurately detecting the faults occurring in the out-of-step oscillation process and quickly restoring the fault clearing ability of distance protection blocked due to the out-of-step oscillation are important for holding the power system security and stability. However, the detection of three-phase symmetrical fault is full of challenges, especially for the condition that fault occurs at 180 degrees, because the out-of-step center voltage drops to 0, the characteristic distinction between out-of-step oscillation and fault becomes weaker. The traditional and the latest proposed methods easily refuse to operate. Under this background, this paper seeks a breakthrough from the perspective of current frequency change. It discovers the current frequency sudden change mechanism before and after fault, and derives the lower limit of the sudden change of current frequency difference between the two terminal buses of out-of-step center locating electrical component. Based on this, a novel scheme is proposed, which effectively solves the difficult fault detection problem at 180 degrees. In this aspect, it has obvious advantage compared with others. Besides, its setting process is very simple and not affected by the fault points, fault moments, and grounding resistances. It has strong practical engineering value and innovation.

Analysis of wind farm penetration on power swing detection in distance relays

Distance protection plays an essential role in the protection of sub-transmission and transmission lines in power systems. However, power swings have occasionally led to the mal-operation of this type of protection. A significant number of large disturbances, such as blackouts, start with power swings. Thus, improving the circumstances leading to this disruptive phenomenon becomes a great priority. Nowadays, the wind power share of worldwide electricity generation and the use of wind farms have increased. As a result, to predict future events, it is necessary to assess the network in the presence of these renewable sources. In this paper, the effects of the wind resources penetration on power swing have been evaluated. Simulations and analyses have been performed in PSCAD/EMTDC and MATLAB environments, respectively. To provide a comprehensive analysis, maximum power passing through the transmission line and power swing frequency have been utilised as criteria. The results show that wind farms presented acceptable behaviour in the presence of power swing and instability. Therefore, in view point of a power swing, induction generator based wind power plants, compared to synchronous generators, led to better overall conditions. Finally, the effect of fixed and variable speed wind turbines on power swing is compared.

Interference Management for the Coexistence of DTTV and LTE Systems within the Proposed Digital Dividend Band in Nigeria

This paper seeks to present the Interference Management for the Coexistence of DTTV and LTE Systems within the proposed digital dividend band in Nigeria. The study focused on LTE Down-link (DL) signal from the nearest cell site interfering with the Digital Terrestrial Television (DTTV) fixed outdoor receiving antenna in Port Harcourt, Nigeria. The qualitative signal analysis of the DTTV systems is essential as DTTV system cannot start to operate in the newly formed frequency band without the evaluation of the possible harmful influence of the coexisting systems. This research work investigated the Compatibility of the two systems and the Probability of interference of Channel 17 (490MHz) and Channel 51 (693MHz) when DTTV and LTE systems coexist within the proposed Digital Dividend band. A test-bed approach method was adopted for the generation of the required simulation data. Star Time transmitting Station in Port Harcourt and Smile LTE 4G Communication LTE Base Station (eNBs) Network also in Port Harcourt were adopted as the Victim Link Transmitter (VLT) and Interfering Link Transmitter (ILT) respectively. Data was obtained, analyzed, and evaluated. It was observed from the simulation result that the probability of interference is a function of the separation distance between ILT and VLR. The Compatibility analysis result shows that the resulting C/I is above the protection criteria (19dB), that is there’s a minimal rate of interference. Hence, the interference issue can be managed when the two systems coexist in700MHz band. It was also established that DTTV channel 51 suffers more interference when compared with DTTV channel 17 for the same separation distance. The study recommended the minimum protection distance approach (Interference Avoidance method) as the interference management techniques when DTTV and LTE systems coexist in the proposed digital dividend (700MHz) band in Nigeria.

Modeling the environmental, health, and safety aspects of xylene isomer emission from storage tanks in petrochemical industries, Iran.

The release of xylene isomers from storage tanks poses a significant threat to petrochemical industries, and their safe transportation and storage is a widely researched topic. This paper focused on modeling the environmental, health, and safety effects of P-xylene and O-xylene leakage from storage tanks via Areal Locations of Hazardous Atmospheres (ALOHA) and Wireless Information System for Emergency Responders (WISER). The meteorological data of the area, characteristics of the tanks, and the roughness of the land surrounding the tanks were used to run the ALOHA model. The dispersion distances of P-xylene and O-xylene toxic and flammable vapor clouds were estimated according to the Immediately Dangerous to Life or Health (IDLH) and lower explosive limit (LEL) criteria. Also, the levels of thermal radiation due to the burning of P-xylene and O-xylene were estimated. The results showed that in the cold seasons, the IDLH was a maximum distance of 62m and 45m for P-xylene and O-xylene, respectively. The LEL criteria were 10% with a magnitude of 1100ppm for a maximum distance of 54m and 35m for P-xylene and O-xylene, respectively. The maximum distance of 20m for O-xylene based on the results of the LEL criteria of 60% (6600ppm) was attained in the warm seasons. They are potentially lethal within 60s at 21m (10.0kW/m2) when burned. The WISER software predicted the protective distance for xylene isomers to be about 300m. The results show that creating a protective zone around the P-xylene and O-xylene tanks with a radius of 54m is necessary to reduce hazards.

Power-Based Concept for Current Injection by Inverter-Interfaced Distributed Generations during Transmission-Network Faults

This paper analyzes the influence of inverter-interfaced distributed generations’ (IIDGs) response during transmission network faults. The simplest and safest solution is to switch IIDGs off during network faults without impacting the network voltages. A more elaborate and efficient concept, required by national grid codes, is based on controlling the IIDGs’ currents, involving positive- and negative-sequence voltage measured at the connection point. In this way the magnitude and phase of the injected currents can be adjusted, although the generated power will depend on the actual line voltages at the connection point. Therefore, an improved concept is proposed to adjust IIDGs’ fault current injection through the required active and reactive power, employing the same voltage characteristics. The proposed, i.e., power-based concept, is more definite than the current-based one, since the required power will always be generated. The discussed concepts for the fault current injection by IIDGs were tested in different 110-kV networks with loop and radial topologies, and for different short-circuit capabilities of the aggregated network supply. Based on extensive numerical calculations, the power-based concept during transmission networks faults generates more reactive power compared to the current-based concept. However, the voltage support by IIDGs during transmission networks faults, regardless of the concept being used, is influenced mainly by the short-circuit capability of the aggregated network supply. As regards distance protection operation, it is influenced additionally by the network topology, i.e., in radial network topology, the remote relay’s operation can be delayed due to a largely seen impedance.

Power swing detecting method using principal components analysis

During power swing, the distance protection is easily affected by the oscillations of voltage and current which may lead to the mal-operation of the protection. Therefore, a power swing detecting unit is needed to cooperate with distance protection. In this paper, a power swing detecting method based on the difference between the structure of transmission line under fault situations and that under power swing situations is proposed. Principal component analysis is deployed to process the voltage and current data to extract the structure feature of the transmission line under power swing and fault situations. To test the effectiveness of the proposed method, a simulation system is built in PSCAD/EMTDC and different disturbance scenarios are done. The test results indicate that the proposed method can reliably distinguish between power swing and fault situations. Besides, a comparison between the proposed method and methods mentioned in other works is been done. The comparison results show that the proposed method has an advantage in operating speed and is less affected by measuring noise.

Experimental Investigation of Surge Propagation Characteristics on a Substation Grounding System

With the correct choice of the arrester by voltage class and compliance with the calculated protective distance without taking into account the propagation velocity of the current wave on the grounding grid, overvoltages exceeding discharge or residual voltage may occur on the protected equipment, in particular the transformer. Thus, when calculating the installation of the arrester that protects the substation from incoming lightning surges from a transmission lines, it is necessary to take into account the propagation of the current wave on the grounding grid. The propagation velocity of electromagnetic waves in a 150 kV substations grounding grid was measured. The measured wave propagation velocities are in the range of 50–100⋅106 m/s. Thus, the obtained velocity of wave propagation on the grounding grid used in service is several times less than the speed of light. The measured value correlates well with similar experiments conducted for buried conductors located in soils with similar parameters and the results of mathematical modeling for a grounding grid having similar dimensions and mesh size.

Human-Machine Differentiation in Speed and Separation Monitoring for Improved Efficiency in Human-Robot Collaboration.

Human–robot collaborative applications have been receiving increasing attention in industrial applications. The efficiency of the applications is often quite low compared to traditional robotic applications without human interaction. Especially for applications that use speed and separation monitoring, there is potential to increase the efficiency with a cost-effective and easy to implement method. In this paper, we proposed to add human–machine differentiation to the speed and separation monitoring in human–robot collaborative applications. The formula for the protective separation distance was extended with a variable for the kind of object that approaches the robot. Different sensors for differentiation of human and non-human objects are presented. Thermal cameras are used to take measurements in a proof of concept. Through differentiation of human and non-human objects, it is possible to decrease the protective separation distance between the robot and the object and therefore increase the overall efficiency of the collaborative application.

Study on Online Dispatching Defensive Strategy for Power Grid Considering Expected Circuit Breaker Fault Set

In order to prevent serious blackouts caused by cascading faults, a defense strategy which considers the expected circuit breaker fault set is proposed for online despatching that is applied to power grid protection. In this paper, the multi-stage game model has been established to study the online defense strategy of circuit breaker failure from the perspective of attacker and defender. From the perspective of attacker in the power grid, the initial expected fault set based on the circuit breaker defect prediction is taken as the initial action. Considering the two factors that the removal of the power flow transfer branch and the incorrect operation of the zone III distance protection because of hidden fault. Then, a strategic space for the attacker is formed by using the risk theory predict the operation of power grid. From the perspective of the defender, a method for adjusting the power system using sensitivity control and adaptive adjustment of the backup protection setting is proposed. The paper finds the optimal strategy for both parties through defining the profit function. Finally, the IEEE 39-bus system is taken as an example to analyze the model, and the simulation results verify the feasibility of the article model.

A distance protection scheme for HVDC transmission lines based on the Steady-state parameter model

To improve the performance of the protection scheme for HVDC lines, a novel distance backup protection scheme is proposed in this paper. First, it is proved that the DC line model can be equivalent to lumped parameter model during the steady-state. Based on the equivalent model, the fault distance can be calculated, and the criterion of the distance relay is implemented. Secondly, a directional relay based on the transient currents is added to solve the dead zone problem of distance protection. Finally, a ± 800 kV HVDC system is built in PSCAD/EMTDC simulation environment to test the performance of the protection. Comprehensive test studies show that the proposed protection scheme can correctly distinguish internal faults from external faults. Besides, the proposed protection has a clear setting principle, low requirements of the calculation amount and sampling rate.

Influence of venting coefficient on disastrous effects of aluminium powder explosions

Aluminium powder has a very high risk of explosion. To clarify the disastrous effects of the overpressure and high temperatures during an aluminium powder explosion in a constrained space and the distribution of the outdoor safe distance, the explosion and venting processes of aluminium dust in a large-scale building were investigated under different venting coefficients, Kv (Kv = Av/Ap), using computational fluid dynamics (CFD). The results show that although an increase in the venting coefficient can reduce the indoor overpressure and explosion temperature, it can also increase the distance up to which the outdoor overpressure and high temperature can cause damage. Moreover, the distance up to which explosion overpressures can be harmful to personnel and buildings increases with an increase in the venting coefficient. Hence, the safe outdoor distance may be more than 1.5–2 times the fire safe distance listed in the Chinese Code for fire protection design of buildings. The high-temperature damage caused by the explosion also increases with an increase in the venting coefficient. Therefore, the current explosion safety protection distances for aluminium powder production sites need to be revised.

A Qualitative Comparison of Distance-Based Protection Approaches for Active Distribution Networks

Objective: This paper presents a qualitative comparison of different recently proposed network protection schemes that are based on the distance function. From this comparison, possible opportunities are identified to develop strategies oriented towards protecting active distribution systems. Methodology: This research is carried out in two parts: the first is to identify the fundamental theoretical aspects of distance protection, its main problems, and a description of the most important aspects of the relevant strategies proposed in recent years. The second part consists of selecting aspects and elaborating a qualitative comparison of the different protection schemes analyzed. This comparison makes it possible to establish the advantages and disadvantages of each of the relevant proposals used in conventional electrical networks or active distribution networks. Results: As a result of this research, the most important aspects to consider in the protection design are identified, which therefore strongly affect its performance. These are summarized in a comparative table, which supports future research related to distance protection in active distribution networks. Conclusions: From this research, it can be stated that the solutions analyzed, despite being relevant within the scope of distance protection applied to active distribution networks, have problems to solve. None of these strategies protects the network for all types of failures in a selective, sensitive, reliable, and cost-effective way while guaranteeing minimum supply interruption to consumers. Funding: This paper is a result from projects 6-20-6 funded by Universidad Tecnológica de Pereira and contract 774-2020 (Integra2023) funded by Minciencias, Colombia.

Urban Green Infrastructure and Green Open Spaces: An Issue of Social Fairness in Times of COVID-19 Crisis

At the time of the restrictions and lockdown during the COVID-19 pandemic, it became apparent how difficult it is for city dwellers to adhere to the prescribed behavioural measures and the protective distance in densely built urban areas. Inner-city parks and green spaces were heavily used for recreational purposes and were thus periodically overcrowded. These observations highlight the need for green open spaces in urban areas, especially in exceptional situations regarding pandemics and climate-related heat periods. Green open spaces and greened buildings help cities and the population cope with the consequences of climate change and have a decisive positive effect on human health and well-being. This paper aims to outline which social issues are related to the availability of green infrastructure close to home and which health consequences need to be considered. The COVID-19 challenges could offer a chance and an opportunity to increase the resilience of cities and their inhabitants in various terms. A cross-disciplinary team of authors (public health, urban and landscape planning, landscaping and vegetation technologies science) describes and discusses challenges and opportunities that arise from this crisis for cities from an inter-disciplinary perspective, concluding that urban green infrastructure helps in two ways: to adapt to climate change and the challenges posed by COVID-19.

Rotating negative-sequence phasors for blocking and unblocking the distance protection during power swings

When power swings occur in transmission lines, the apparent impedance seen by the distance relay can shift toward the protection zone. This may result in unwanted trips in the protection system. This study proposes novel algorithms for detecting power swings and performing power swing blocking (ANSI 68) and unblocking through fault detection during power swings. The algorithms are free of settings and apply mathematical tools employed in commercial relays, such as the Fourier filter and symmetrical components. They are based on an analytical solution originally proposed in this study that demonstrates that negative-sequence phasors present a rotating behavior during a power swing, which can be used as a fundamental principle for power swing detection. The IEEE 9-bus electrical system is implemented in Matlab/Simulink to validate the proposed algorithms. The results show that the proposed algorithms effectively achieve blocking through power swing detection and achieve unblocking through fault detection. The latter function is shown to perform better than two algorithms available in the literature.

A novel instantaneous value based incremental quantities distance protection for AC transmission lines

Conventional distance protection elements are predominantly based on voltage and current phasors. As a result, those elements require the half-cycle/full-cycle time window to estimate the accurate voltage and current phasors. Using information in the transients of voltages and currents is a possible way to improve the distance protection operation speed. To break free of phasor limitations, this paper presents a novel incremental quantities distance protection algorithm based on instantaneous values of voltage and current. Firstly, the instantaneous voltage distribution along the AC transmission line is analysed. Then, the principle of the incremental quantities distance protection is presented. The influence of fault angle on the presented algorithm is also analysed and a solution is proposed to deal with the relative small fault angle conditions. Finally, an extensive simulation results based on PSCAD/EMTDC simulation verify the performance of the presented incremental quantities distance protection.