Power System Transmission Research Articles

An efficient transmission algorithm for power grid data suitable for autonomous multi-robot systems

Under the power environment of Internet of things used in autonomous multi-robot systems, due to the influence of various actual environmental factors, the security protection method based on security partition and physical isolation of nodes is difficult to fully meet the information security protection requirements of the power system, and the network threats such as impersonation, eavesdropping, and dexterity on communication links are still difficult to avoid. In order to improve the security of node data transmission in autonomous multi-robot power systems, reducing network energy consumption has become the bottleneck of network application and development. In this paper, we propose an Improved Effective Clustering Algorithm (IECA) and transmission algorithm of power grid data based on autonomous multi-robot systems. The distance between nodes sending data to the next-hop node is equivalent to the energy model. The remaining energy in the cluster head node sending data in the next hop is recorded, and the remaining energy is subtracted from the equivalent energy to find a maximum value. The corresponding node of the maximum value is taken as the number of nodes According to the received node. Compared with the LEACH algorithm and GAF algorithm, this algorithm can not only extend the lifetime of nodes but also has more efficient performance.

Application of small-scale compressed air energy storage in the daily operation of an active distribution system

While compressed air energy storage (CAES) has many applications in the field of generation and transmission power systems based on the state-of-the-art, this paper proposes the application of small-scale CAESs (SCAESs) in form of a storage aggregator in the daily operation of an active distribution system (ADS), joining the distribution system operator (DSO) for the participation in the day-ahead (DA) wholesale market. An innovative two-agent modeling approach is formulated. The first agent is responsible for aggregating SCAES units and the profit maximization of the aggregator is based on the distribution local marginal price. The DSO as the second agent receives the DA scheduling from the independent SCAES aggregator and is thus responsible for the secure operation of the ADS, utilizing solar and dispatchable distributed generation (DG) as well as purchasing power from the wholesale market. Linear programming is used for the formulation and optimization of the SCAES aggregator, while a bi-objective optimization algorithm (with the objectives of minimum operating cost as well as minimum power loss and emissions in different scenarios) is employed for DSO scheduling. The results show that the CAES aggregator can offer a considerable impact for power loss reduction, specifically, when diesel generators are not committed in the system operation (i.e., where emission has very low values between 10,000 and 12000 kg). Additionally, the CAES aggregator could reduce the operation costs of the grid in a wide range of operations, even though for the scenario in which the CAES units are not under the control of the DSO anymore and also are scheduled to maximize their own profit. Moreover, results demonstrated that CAES units can be a significant voltage control device for a distribution grid with different objectives. Finally, some conclusions are duly drawn.

Assessment and Integration of Renewable Energy Resources Installations with Reactive Power Compensator in Indian Utility Power System Network

Renewable energy (RE) resource assessment is essential for planners and investors to increase its penetration capacity, and improve social and economic security. Integration of renewable power generations (RPGs) and reactive power compensators (RPCs) offer potential benefits to the existing power system network by providing a prospect for voltage control, reduction in power losses, sustainability, and reliability improvement. There are proven outcomes with these RPGs and RPCs placement in distribution systems. This work proposes a candidature location and sizing of RPGs and RPCs optimally in the Indian utility transmission power system network. The foremost purpose of this integrated operation at multiple nodes is to increase the performance of the power system concerning power loss and voltage deviation reductions, and voltage stability improvement. The loss sensitivity factor (LSF) based particle swarm optimization (PSO) technique is adapted for finding the candidature locations and sizing the RPGs and RPCs under five different configurations. Simulation outcomes display the proposed methodology can lead to extensive performance enhancement in the power system towards the sustainable development of electric energy transactions. Further, renewable resource assessment is carried out to find the viability of the candidature locations. The potential of wind and solar energy resources is assessed widely and suitable tools are used to evaluate the power extraction through RE at these selected locations. The results show that the candidature locations have great potential to evacuate the energy, which can effectively improve the existing power system technically and economically. Additionally, it is attested that the RPGs can also be utilized for power system enhancement.

Recent Advances of STATCOM in Power Transmission Lines – A Review

Internal Liability of power system transmission lines influenced by the turbulences owing to catastrophic disasters. In order to achieve Constant Voltage Stability at both ends of the transmission lines, Static Synchronous Compensator (STATCOM) is imperative. Voltage source Converter mechanisms augment with switching frequency control methodologies are widely adopted to regulate the reactive power. By deliberating IEEE Standards, the minimization of Total Harmonic Distortion (THD) is conceivable with STATCOM. This paper depicts the advancement of VSC based STATCOM approaches and the methodologies to minimize the switching losses. Economical management of High-Power ratings systems is also discussed in this paper

Reliability tracking method of power system equipment based on Embedded Internet of things technology

Power equipment is one of the most important transmission and transformation equipment in power system. Improving the reliability of power equipment is of great significance to the safe and reliable operation of the whole power grid. A reliability tracking method of power system equipment based on Embedded Internet of things technology is proposed. The minimum cut set algorithm of reliability index based on Embedded Internet of things technology is given. In this paper, a fault tree analysis method for power system equipment unreliability index is proposed. According to the analysis of equipment structure, component function and failure mode, the fault tree model of power system equipment is established, and the reliability tracking calculation example is analyzed. Experiments show that the method can track the order stably, determine the key components that affect the reliability of the equipment, and identify the weak links of the equipment.

Local dynamic frequency response using domestic electric vehicles

There is an increasing interest to penetrate low carbon vehicles into the transport system. Take the Great Britain (GB) as an example, the number of electric and plug-in hybrid vehicles will make up to at least half of new vehicle sales. Electric vehicles (EVs) are expected to contribute to the ancillary services of the frequency response because EVs can provide immediate frequency response and sustain its response for considerable period of time. This paper addresses the design of a Dynamic Vehicle Grid Support (DVGS) control algorithm for the provision of local frequency response. The DVGS considers a dynamic relationship between the state of charge of EVs and frequency set-points. Thus, it can be installed locally avoiding the cost and the time delay associated with the communication system between EVs and the control centre. The DVGS control algorithm was demonstrated using the reduced GB transmission power system model with a reduced system inertia. The simulation results showed that the EVs are promising assets for the provision of frequency response and reducing the rate of change of frequency (RoCoF). Moreover, EVs can be controlled geographically to provide the zonal frequency response, reducing the dependency on the power from the spinning reserve, especially with a reduced system inertia. The financial benefits of using the aggregated DVGS for firm frequency response (FFR) service in the GB is calculated.

Investigating Small Modular Reactor's Design Limits for Its Flexible Operation With Photovoltaic Generation in Microcommunities

Abstract Use of flexible and dispatchable generation from the small modular reactors (SMRs) in combination with the nondispatchable generation from renewable energy systems (RES) can be an effective alternative to pursue the mandate of replacing the fossil-fuel based electricity with the carbon-neutral energy systems in the remote microcommunities. This paper evaluates the feasibility of SMRs' flexible operations in microcommunities with the photovoltaic (PV) generation as a case study. Considering the design limits of SMRs for (a) the range of net change in electrical power output and (b) the ramp rates of net change in turbine power, a power system study is conducted to cover the three aspects of flexible operations, namely: (1) Planned load-following, (2) Unplanned load-following, and (3) Frequency regulation. A generic governor model in power system simulator for engineering (PSS/E), a power system transmission and planning software, is adapted to incorporate the operating limits of the reactor for the dynamic simulation. The multitimescale approach, combining (a) steady-state time-series power flow analysis and (b) dynamic simulations with high-resolution solar irradiation datasets, is proposed to assess the implications of SMR's design limits. The results obtained on an existing remote feeder with three sets of operating limits—namely, the conventional, advanced and extreme limits of ramp rates juxtapose the SMRs' performance, given the challenging operating conditions with PV generation in remote locations. The results indicate that the SMR under study can accommodate the highest permissible PV penetration obtained by the hosting capacity analysis of the feeder under the clear sky conditions. However, dynamic simulations with the extreme PV variabilities show that the PV penetration level should be further limited so that the maximum deviations in SMR power levels stay within 40% of its rated capacity. SMR provides adequate frequency support for the PV penetration of up to 50% of the feeder maximum demand in this study.

Storage-Transmission Joint Planning Method to Deal with Insufficient Flexibility and Transmission Congestion

The insufficient power system flexibility and transmission congestion are two fundamental reasons for wind power curtailment. As the scale of the wind power in the power system is growing rapidly, the two factors of wind power curtailment events coexist and have a certain coupling relationship. The configuration of the energy storage system can not only increase the flexibility of the system but also alleviate transmission congestion. Therefore, the joint planning of energy storage and transmission grid that takes into account the flexibility of the system and the transmission congestion is of great significance to solve the wind curtailment. Hence, this paper first decouples the insufficient flexibility and transmission congestion wind power curtailment, and quantitatively analyzes the impact of transmission capacity on the coupling relationship between the two; second, reveals the principle of joint planning of energy storage system and transmission congestion, and constructs an optimization model, and proposes to set up the capacity of the wind power which connects the power network. The solution procedure, which deals with grid planning and the energy storage system optimization in turn, not only ensures the accuracy of the model, but also significantly reduces the calculation cost. Finally, a case study of a wind power base in Northeast China and an improved Garver-6 system are carried out to verify the effectiveness of the proposed method.

Failure Analysis of Power Transformer Based on Transformer Turn Ratio Test and SFRA

A power transformer is one of the most key components of energy transmission and distribution in an electric power system. Inter-turn disturbances or short circuit faults may occur because of insulation degradation between one or more successive turns of the windings. If the fault is not detected early, it may spread to the nearest winding turn and causes permanent damage to the winding. Therefore, it is necessary to detect inter-turn faults to prevent catastrophic failure of the transformer. In this study, failure analysis of a transformer that approaching the catastrophic stage is conducted using sweep frequency response analysis (SFRA) and transformer turns ratio (TTR) testing methods. Correlation between SFRA & TTR tests is analyzed. TTR test before rewinding is > 0.5%, while after rewinding is < 0.5%. 400 VAC voltage is applied, and the output voltage is measured. SFRA and TTR results show that there is a linear correlation for all phases. It can be concluded in this study that the TTR test can be used to detect transformer failure.

Analysis of the Response of Transmission Line Network under Electromagnetic Pulse

Power system transmission line is a very complex network. The response of cable terminal is very different from that of single line. In order to accurately predict the terminal response of the cable under the nuclear electromagnetic pulse, a convenient method is needed to calculate the response of complex network. Based on the state equation method and the extrapolation method, the transmission line is equivalent to the current source or voltage source. Matlab program and Simulink are used to calculate the induced current generated by the cable terminal. The results are compared with those of CST cable studio. The results of CST show that the method is correct.

Public acceptance of renewable electricity generation and transmission network developments: Insights from Ireland

This paper analyses how people’s attitudes towards onshore wind power and overhead transmission lines affect the cost-optimal development of electricity generation mixes, under a high renewable energy policy. A power systems generation and transmission expansion planning model is used for the analysis, combined with a novel additional modelling constraint incorporating public acceptance of energy infrastructure. In the scenarios examined the least cost solutions increase by as much as 33% compared to a base case where the constraint on public acceptance of energy infrastructure is excluded. In the most extreme public acceptance scenario considered, the greatest share of additional costs (>80%) is related to value of lost load, while additional investment and operational costs associated with public acceptance constraints for new energy infrastructure are between 5–6% of base case costs. The results are indicative of the cost that power systems face in reflecting the public’s preferences for new energy infrastructure in generation and grid expansion planning. Power system modelling that ignores the public’s acceptance of new energy infrastructure may offer generation or transmission pathways that are likely to be sub-optimal in practice. • Power system generation and transmission modelling with public preference constraints. • Public generally supportive of wind farms but less so when close to homes. • Power system cost up to 33% higher as public opposition to energy infrastructure increases. • Greatest share of additional costs associated with value of lost load.

Hybrid Control for Power System Based on STATCOM and UPFC with Two 3-level 48-pulse under Different Conditions

This research presents the proposed model, to control the power flow in the transmission power system by applying Unified Power Flow Controller (UPFC), STATCOM and two 3-level 48-puls converter. This hybrid has been used to improve performance and reduce the maximum over shoot which is obtained from proposed model when the fault is occurring or suddenly system changes. The behavior of the system is analyzed under different three cases. The first case, the model is applied to plus load at bus 3. The second case, the model is operating at normal work and the third case, the three phase fault is occurred at bus4. In this research, the performance of system is studied under applied all cases of the current, voltage and power for the system. The numerical results of the proposed model are introduced to show the maximum over shoot and RMS values after applied proposed control at three different cases to prove the suggested model gave a good performance especially, during three phases fault and after fault clearance.

RETRACTED: Computer-aided physical training sports injury risk simulation based on embedded image system

In teamwork, injuries occur from time to time. The athlete's body is very important, so the rich experience of teamwork can reduce the injury to the athlete, which is a very important aspect of preventing the risk and mitigating the risk. There are several ways to reduce the risk factors of injury. One is to use positioning method, scientists have developed a 2.4 GHz frequency wireless receiving sensor system, referred to as WSN. This system can effectively monitor indoor and outdoor environment and identify and analyze buried active RF in advance. After several frequency tests, more effective performance is obtained, and the transmission power and signal intensity system are developed. It can generate high-frequency amplitudes, and the transmitted data can create independent labels to receive. However, the difficulty in understanding the subtle differences between different statistical methods and making conclusions that lead to erroneous assumptions has been produced from the data. Therefore, the purpose of this study is to obtain the outline to determine the method used to determine the risk of damage, to predict the movement of injuries while developing the model and the existing evidence to highlight the difference between the association and the prediction associated with damaging it. Sports injuries risk factors research aimed to study the example of the method is evaluated using chopped strains. Injuries resulting from the complex interaction of several risk factors. Develop and adapt and, mental, emotional, social events. Therefore covers education system and the necessary physical activities organized by physical education. In order to create a rough picture of the whole creation and technique. The soap places to students who have used a solvent, is embedded in the grease.

Optimal reactive power dispatch: a bibliometric analysis

Optimal reactive power dispatch (ORPD) plays a significant role in the control and smooth operation of the power system through the enhancement of the network’s reliability, security, and economic aspects. This paper presents a bibliometric and visual analysis of ORPD-related research articles extracted from the Web of Science (WoS) database from its inception to October 29, 2019. A total of 263 articles drawn from 166 journals, published between 1989 and 2019, were retrieved and analysed using Excel, HistCite, and VOSviewer visualisation software. The total number of citations for the 263 articles ranges from 0 to 297. The top three journals with the most significant number of ORPD publications were the International Journal of Electrical Power and Energy Systems, Applied Soft Computing, and two journals qualified for the third place, IEEE Transaction on Power Systems and IET Generation Transmission and Distribution. The most active researcher is Provas Kumar Roy, with nine (9) articles from Kalyani Government Engineering College. The most trending/cited researcher is Yi Jia Cao, with 129 Total Local Citation Scores from Hunan University, Changsha. In terms of contribution by countries, India, China, Iran, and the United States were the most significant contributors with 27.8%, 20.9%, 11.8%, and 8% of the total articles, respectively. The top 5 most frequently used substantive keywords to identify the trending topic and research direction were Particle Swarm Optimisation, Genetic Algorithm, Gravitational Search Algorithm, Linear Programming, Evolutional Algorithm, and Hybrid Algorithm. This study provides a detailed outline and reveals the future research directions for both experienced and novice ORPD researchers to identify research topics, questions, and collaboration partners.

A continuous variable quantum key distribution protocol based on multi-dimensiondata reconciliation with Polar code

The continuous variable quantum key distribution protocol (CV-QKD) has the advantages of easy generation of quantum signals, convenient measurement and high communication capacity. However, the multi-dimensional data reconciliation is mainly implemented by binary LDPC code as quantum error correction code, which is greatly affected by complex environments and the bit error rate is high. In order to solve this problem, acontinuous variable quantum key distribution protocol based onmulti-dimension data reconciliation with Polar code, that can be applied to long-distance transmission in power systems, is proposed. First, we prepare an EPR quantum state, and perform heterodyne detection on one of the quantum states, and obtain the values of two orthogonal components at the same time which is the coherent state of the information carrier. Then the continuous variable quantum key distribution is realized by six steps (i.e., quantum state preparation, gaussian random detection, data filtering, calculation of bit error rate, data reconciliation, privacy amplification).In data reconciliation, we use Polar code as the error correction code and use reverse coding technology to achieve key error correction, which can effectively improve the negotiation efficiency. Numerical simulation verifies the feasibility of the protocol, and the protocol is more efficient than the multi-dimensiondata reconciliation protocol based on LDPC code under the same conditions.

Study on Sound Field Distribution Rule for Tank Structures of Large Oil-immersed Transformers

Large oil-immersed transformers are an important part of the transmission and distribution network in power systems. Power transformers are the main noise source of substations. Because of the uneven manufacturing process, aging equipment, long-term operation, and close distance from sensitive points, the problem of transformer noise pollution has become increasingly prominent. In this paper, the transmission and analysis model is established for transformer sound waves on the interface between insulating oil and tank body according to the sound wave propagation rule in complicated medium, and the simplified acoustic simulation model is constructed for large oil-immersed transformers by simulating the vibration noise of transformer core with monopole sound source, with which, the sound field distribution rule inside and outside the transformer tank structure is obtained, and finally, the influence factors for noise distribution are given. The results of the study provide control basis for reducing transformer noise.

Reliability of a Power System With High Penetration of Renewables: A Scenario-Based Study

Reliability is a crucial consideration in the expansion of generation or transmission in a bulk power system, especially in a power grid with a high penetration of renewables. Reliability indices, such as loss of load probability (LOLP), are generally evaluated to determine the adequacy of a bulk power system in the future. When a Monte-Carlo simulation is conducted to evaluate the LOLP, the computational time is long because chronological time-series data are involved. This work proposes a novel scenario-based method for studying the LOLP in a bulk power system with a high penetration of renewables. Scenarios are generated by aggregating Markov states of hourly loads, photovoltaic power generations and wind power generations. The power flow result in each scenario is examined to ensure power balance among demand, supply and losses, so the LOLP can be obtained. This novel scenario-based method is more efficient than the traditional chronological time-series approach because the number of considered scenarios is much smaller than the number of considered time-series cases. A set of realistic data regarding Taiwan power system, consisting of 2078 buses associated with a peak load of 39.178 GW, wind power of 6.938GW and photovoltaic power of 20 GW in 2025 is used to validate the proposed method.

Optimal Location of FACTS Devices in Order to Simultaneously Improving Transmission Losses and Stability Margin Using Artificial Bee Colony Algorithm

It is not possible to use the full capacity of the transmission lines due to voltage limitations and stability issues. Therefore, compensators must be used to improve the transmission line capacity. One of the suggested ways for this purpose is to use flexible alternating current transmission system (FACTS) devices in the power system. The various capabilities of the FACTS devices have made it possible to set different targets to determine their optimal location and position. Some of the most important placement targets include increasing voltage stability, improving voltage profiles, reducing losses, increasing line capacity limit and reducing fuel costs for power plants through optimal power distribution. In this paper, optimal locating of FACTS devices to improve power system stability and transmission line losses reduction. Also, artificial bee colony algorithm is proposed for solving optimization problem. The artificial bee colony algorithm with high accuracy and high convergence speed is suitable for conducting FACTS placement studies. Finally, a comparison was made between the artificial bee colony algorithm and genetic algorithm (GA) and particle swarm optimization (PSO) algorithm. The results indicate that the artificial bee colony algorithm works better than the other algorithms in minimizing the fitness function.

A real-time fault diagnosis system for high-speed power system protection based on machine learning algorithms

This paper puts forward a real-time smart fault diagnosis system (SFDS) intended for high-speed protection of power system transmission lines. This system is based on advanced signal processing techniques, traveling wave theory results, and machine learning algorithms. The simulation results show that the SFDS can provide an accurate internal/external fault discrimination, fault inception time estimation, fault type identification, and fault location. This paper presents also the hardware requirements and software implementation of the SFDS.

Weight Calculation Alternative Methods in Prime’s Algorithm Dedicated for Power System Restoration Strategies

In self-healing grid systems, high utility in the use of greedy algorithms is observed. One of the most popular solutions is based on Prim’s algorithm. In the computation, the power grid is represented as a weighted graph. This paper presents a few possibilities of calculation of the numerical weight of a branch of the graph. The proposition of a modified edge weight calculation based on active power belongs to this group. The other solutions are novel subalgorithms bounded by real power, reactive power, and normalized factor. This factor is a mathematical combination of active and reactive power multiplied by influence coefficients. Requirements necessary for a power system are applied in the considered algorithms. Each of these proposed algorithms includes the power source limits, voltage level at busbars, and power system transmission features, such as transmission lines rated currents and power losses. All mentioned methods were compiled into separate algorithms, which can be used to compute graph model parameters. A simulation model based on Prim’s algorithm was prepared to compare the suitability of presented concepts. All weights of the subalgorithms were compared to each other. That is why different power system restoration strategies may require various methods of calculating weights of the graph’s branches.