Radial System Research Articles

Analysis of the stability of automatic tracking of super maneuvering air objects by radio technical tracking systems of the multichannel radar

Multichannel tracking radars with phased antenna arrays are widely used to track air targets. The use of a phased array in combination with digital computing technology allows to control the radar radiation pattern and track several targets in the time distribution mode. Air target tracking in a multichannel radar is provided by subsystems for measuring range, radial velocity and angular coordinates, in most cases, without adaptation to the external influence characteristics. When tracking supermaneuverable air targets, such as 5th and so-called 4++ generation fighters, there is a decrease in the accuracy and stability of tracking relative to the area without maneuver. If the tracking system algorithms are tuned to a low intensity of maneuvering or its absence, a significant increase in the error of tracking the aircraft in the maneuvering section will lead to disruption of auto tracking due to a significant dynamic component of the error. The stability of auto-tracking of maneuvering targets by subsystems of range, radial velocity, and angular coordinates with fixed parameters for the case when the setting of the parameters of the tracking system algorithms coincide with the characteristics of the external influence is analyzes in the paper. The influence of the observation model parameters, the stochastic model of the target movement with exponentially correlated values of the target acceleration, and the measurement period of the target coordinates on the potential tracking accuracy by radio technical tracking systems of the multichannel radar is investigated. To assess the stability of auto-tracking, it is proposed to use the equivalent aperture size of the discriminating characteristic. The influence of the parameters of the target movement stochastic model, the observation model, and the measurement period of the target coordinates on the stability of auto-tracking in terms of range, radial velocity, and angular coordinates is estimated. It is shown that the "weak link" is the radial velocity tracking system. As a result of the research carried out, it becomes possible to further assess the feasibility of adapting the auto-tracking systems to the target maneuvering characteristics and to develop recommendations for choosing the measurement period of the target coordinates.

A Transfer Function Model Development for Reconstructing Radial Pulse Pressure Waveforms Using Non-Invasively Measured Pulses by a Robotic Tonometry System.

The primary goal of this study is to develop a mathematical model that can establish a transfer function relationship between the “external” pulse pressures measured by a tonometer and the “internal” pulse pressure in the artery. The purpose of the model is to accurately estimate and rebuild the internal pulse pressure waveforms using arterial tonometry measurements. To develop and validate a model without human subjects and operators for consistency, this study employs a radial pulse generation system, a robotic tonometry system, and a write model with an artificial skin and vessel. A transfer function model is developed using the results of the pulse testing and the mechanical characterization testing of the skin and vessel. To evaluate the model, the pulse waveforms are first reconstructed for various reference pulses using the model with tonometry data. They are then compared with pulse waveforms acquired by internal measurement (by the built-in pressure sensor in the vessel) the external measurement (the on-skin measurement by the robotic tonometry system). The results show that the model-produced pulse waveforms coinciding well with the internal pulse waveforms with small relative errors, indicating the effectiveness of the model in reproducing the actual pulse pressures inside the vessel.

Nanoliquid Jet Impingement Heat Transfer for a Phase Change Material Embedded Radial Heating System

Abstract Nanoliquid impingement heat transfer with a phase change material (PCM) installed radial system is considered. The study is performed by using the finite element method for various values of Reynolds numbers (100 ≤ Re ≤ 300), height of PCM (0.25H ≤ hpcm ≤ 0.75H), and plate spacing (0.15H ≤ hs ≤ 0.40H). Different configurations using water, nanoliquid, and nanoliquid + PCM are compared in terms of heat transfer improvement. Thermal performance is improved by using PCM, while best performance is achieved with nanoliquid and PCM-installed configuration. At Re = 100 and Re = 300, heat transfer improvements of 26% and 25.5% are achieved with the nanoliquid + PCM system as compared to water without PCM. The height of the PCM layer also influences the heat transfer dynamic behavior, while there is 12.6% variation in the spatial average heat transfer of the target surface with the lowest and highest PCM heights while discharging time increases by about 76.5%. As the spacing between the plates decreases, average heat transfer rises and there is 38% variation.

Development of wood-burning rocket cookstove with forced air-injection

Nearly 40% of the world's population still relies on biomass stoves as their primary cooking source. Indoor cooking with biomass stoves produces harmful emissions such as fine particulate matter (PM2.5) and can result in significant cardiovascular and respiratory disease. Air injection technology, in the forms of over-fire, under-fire, and staged (a combination of under- and over-fire), has been used for decades to reduce emissions in small-scale industrial biomass burners. Recently, researchers have begun integrating air-injection into biomass cookstoves, but the number of studies is limited, and improper air-injection can result in worsening stove performance. In this paper, we develop and analyze three wood-burning biomass rocket stove air-injection strategies using computational fluid dynamics and experiments. We consider over-fire and under-fire air-injection independently, and then develop a staged air-injection system that combines the optimal jet characteristics from the purely over-fire and under-fire systems. Results show that significant performance gains, both in terms of reduced emissions and increased burn-rate are achievable with forced air-injection. For a radial over-fire air injection system, jet momentum flux is found to control fuel and air mixing and is the driving metric for reducing particulate emissions. For the under-fire system, excess air ratio was found to control both the emissions rate and firepower. In a comparison of all three air-injection strategies, over-fire air injection was found to have the largest reduction in emissions, under-fire air injection had the largest increase in firepower and reduction in boiling times, and the staged air injection method achieved both improved emissions and burn-rate. Additionally, the combustion start-up phase was observed to account for the majority of emissions in all forced-draft stoves, and is most sensitive to under-fire injection, remaining an area ripe for improvement.

The efficiency of electric power supply with the transmission of peak loads to distributed generation

A model of a radial power supply system in MatLAB was compiled to perform the research. The transformer substation is represented by a step-down transformer, the load of the substations in the form of a resistance. Electricity is transmitted to the substations along three power transmission lines. The power center is represented by an ideal source. A reserve source of limited power is connected to the remote substation. We made calculations of the voltage drop in the lines, voltage at the inputs of substations and electricity losses for transit. The study of the radial power supply system was performed in the daytime maximum mode; the minimum load mode was performed at night and in the peak load mode. As a result of modeling the operating modes, the indicators of the classical radial power supply scheme were compared with the indicators of the system when the local generation facilities were switched on during the working shift or during peak hours. Connection of reserve sources allows reducing voltage fluctuations along the line and reducing power losses for transit.

The experimental study on the coal rock breaking efficiency of the self-rotating multi-orifice nozzle applied in URRS technique

China has abundant coalbed methane (CBM) reserves, but the production of single well is rather low. The Ultra-short Radius Radial System (URRS) technique can drill multiple radial branch holes with hydraulic jetting to effectively improve the production of single well. The high-pressure jet nozzle plays an important role in URRS technique and the structure of nozzle directly affects the efficiency of radial drilling. This paper adopts the experimental study on breaking coal rock efficiency of the self-rotating multi-orifice nozzle with different structures. The uniaxial compressive strength, tensile strength and shear strength of experimental rock samples were tested and calculated. Using natural coal and briquette rock, number of experiments under submerged conditions were carried out. The effects of nozzle pressure, jetting distance, jetting time and jetting direction on rock breaking effect were studied. The experimental results show that natural coal rock has strong anisotropy and demonstrate the coal rock breaking efficiency of the self-rotating multi-orifice nozzle. The key findings are expected to provide theoretical and technical support for development of CBM reserves by using the URRS technique.

Pareto Local Search Function for Optimal Placement of DG and Capacitors Banks in Distribution Systems

DGs and capacitor banks are installed to optimize the performance of many distribution networks. Typically, the problem of optimizing the overall performance of the distribution network is examined with multi-objective purposes. Network optimization purposes are usually varied and sometimes contradictory. Therefore, the problem search space is very large due to the variety of purposes. This paper presents a modified Pareto local search function for optimal placement of DGs and capacitor banks. To limit the search space and find Pareto points, a new combination method including Pareto chart and a weight function has been used. The optimal operation of the distribution network is performed by three single objective functions related to the voltage stability index, voltage profile of buses and power loss. In this method, a modified per-unit system is presented to align single objective functions and their weighting coefficients. The network is studied with three different loads. So that, the network is examined in the final stage by increasing the load and reaching bus voltage stability margins. The particle swarm optimization method is applied to solving placement problems. In addition, locating and sizing DG and capacitor banks, tap setting of on load tap changer transformer is adjusted by the proposed method. To show the effectiveness of the purposed method, simulations are applied to 69 bus radial system. The results indicated the favorable advantage of the proposed method to improve the overall performance of the distribution network.

A Novel Analytical Approach for Optimal Placement and Sizing of Distributed Generations in Radial Electrical Energy Distribution Systems

Considering the strong influence of distributed generation (DG) in electric distribution systems and its impact on network voltage losses and stability, a new challenge has appeared for such systems. In this study, a novel analytical algorithm is proposed to distinguish the optimal location and size of DGs in radial distribution networks based on a new combined index (CI) to reduce active power losses and improve system voltage profiles. To obtain the CI, active power losses and voltage stability indexes were used in the proposed approach. The CI index with sensitivity analysis was effective in decreasing power losses and improving voltage stability. Optimal DG size was determined based on a search algorithm to reduce active power losses. The considered scheme was examined through IEEE 12-bus and 33-bus radial distribution test systems (RDTS), and the obtained results were compared and validated in comparison with other available methods. The results and analysis verified the effectiveness of the proposed algorithm in reducing power losses and improving the distribution system voltage profiles by determining the appropriate location and optimal DG size. In IEEE 12 and 33 bus networks, the minimum voltage increased from 0.9434 p.u and 0.9039 p.u to 0.9907 p.u and 0.9402 p.u, respectively. Additionally, the annual cost of energy losses decreased by 78.23% and 64.37%, respectively.

TPCPF: Three-Phase Continuation Power Flow Tool for Voltage Stability Assessment of Distribution Networks With Distributed Energy Resources

This work presents a three-phase unbalanced continuation power flow algorithm for voltage stability assessment of distribution systems with high penetration of distributed energy resources (DERs). Analyzing distribution system voltage stability with DER will allow high penetration of renewable energy necessary for the sustainability goals. The developed algorithm can analyze voltage stability for both the meshed and radial systems and the balanced and unbalanced three-phase distribution systems. The developed tool allows the voltage stability analysis to facilitate the planning, operation, control, and distribution system management. The impact of DER on the voltage stability of several test cases has been analyzed considering constant power (PQ) and regulated-voltage (PV) modes of operation for DER units. Moreover, different voltage stability case studies are presented to demonstrate the impact of unbalance, load increment, and network topology on the maximum loading capacity. Results using the IEEE 13-node feeder, the 18-bus balanced shipboard system, the 13-node CIGRE benchmark system, and the 136-bus redial distribution feeder demonstrate that the developed continuation power flow tool can efficiently perform voltage stability analysis for active distribution systems.

Early Warning Model of Track and Field Sports Injury Based on RBF Neural Network Algorithm

Track and field events are the foundation of sports events. To learn other sports events well, you must also have a certain grasp of track and field events. As the movements of each track and field event become more and more complex, the competition becomes more and more intense, and the technical requirements are getting higher and higher. Therefore, sports injuries are gradually increasing. The prevention of sports injuries is a hot spot in sports medicine. Studies have found that as many as twenty factors can directly or indirectly cause track and field sports injuries. Based on the collected data on the injury-causing factors of elite athletes’ track and field sports, and on the basis of in-depth research on mobile data processing technology and early warning risks, a mobile early warning system and radial system using sports injury risk early warning algorithms, functional design and architecture are proposed. The basis function (RBF) neural network algorithm is released. Research on Early Warning Model of Sports Injury. This article analyzes and evaluates different hazard factors through the method of literature data, expert review and extensive analysis. In the investigation, the various causes of the injury were analyzed in detail, and it was found that most sports injuries were caused by students’ lack of attention, technical errors, insufficient preparation activities, etc., and finally proposed countermeasures to solve the problem, so that the sports injury situation was obtained improve.

Design of a radial ultrasonic horn for plastic welding using finite element analysis

In this paper, a radial ultrasonic horn is designed by finite element analysis. Three different modes are obtained corresponding to specific natural frequencies. The distribution of amplitude and stresses of resonant mode shape are investigated. The 7075 aluminum grade is utilized for fabricating the radial ultrasonic horn. The ultrasonic sewing machine using the radial horn is established. The measured frequencies of the simulated and machined results are compared. Two kinds of polyvinyl chloride (PVC) tarpaulin fabrics with densities of 220 g sqm−1 and 320 g sqm−1 are welded by the radial ultrasonic welding system. Two patterns of the rollers are utilized for testing the welding ability of the machine. The ultrasonic power, air pressure, and the velocity of the roller are set at 1500 W, 3 kg cm−2, and 6 m min−1, respectively. Good welding joints are achieved. The tensile strengths of welding joints of two tarpaulin sheets are measured as 144.9 g mm−1 and 134.6 g mm−1, respectively.

Reactive Power Support in Radial Distribution Network Using Mine Blast Algorithm

The passive power distribution networks are prone to imperfect voltage profile and higher power losses, especially at the far end of long feeders. The capacitor placement is studied in this article using a novel Mine Blast Algorithm (MBA). The voltage profile improvement and reduction in the net annual cost are also considered along with minimizing the power loss. The optimization problem is formulated and solved in two steps. Firstly, the Voltage Stability Index (VSI) is used to rank the nodes for placement of the capacitors. Secondly, from the priority list of nodes in the previous step, the MBA is utilized to provide the optimal location and sizes of the capacitors ensuring loss minimization, voltage profile improvement, and reduced net annual cost. Finally, the results are tested on 33 and 69 radial node systems in MATLAB. The results for the considered variables are presented which show a significant improvement in active and reactive power loss reduction and voltage profile with lesser reactive power injection.

Protection Coordination Method Using Symmetrical Components in Loop Distribution System

Power utilities worldwide commonly use the radial distribution system because of its advantages of being simple in structure and having relatively inexpensive installation costs. It has a disadvantage in that its power supply reliability is low because the load side of the fault section will suffer from an outage in the event of a fault in the system. However, recently, with ICT (Information and Communication Technologies) development, system reliability is required to be high as the outage-susceptible loads increase. In addition, the increase in the connection of distributed resources such as renewable energy and electric vehicles is making it impossible to predict the power flow and reducing line utilization. Therefore, a loop power distribution system is proposed as a measure to solve this problem. Because all buses (nodes) in a loop distribution system have two or more power supply routes, they are more reliable than the radial system. It allows them to improve line utilization by connecting lines with different load peak times. However, in the case of a fault in the loop distribution system, the fault current is supplied from both directions, making it impossible to properly isolate the fault section with the protection method of the conventional distribution system. The permissive overreach transfer trip (POTT) method using communication to compensate for the limitations of conventional protection devices, and the other method using directional distance relay, is proposed. However, these methods operate by determining the direction of the fault current but have a disadvantage. It is difficult to detect a fault due to the effects of ground faults and distributed generation (DG) occurring in other lines. Therefore, in this paper, we propose a protection coordination algorithm that uses the negative-sequence component of voltage and current that occur when an unbalanced fault occurs, rather than the determination of the directionality and use of communication. To validate this, we configured a system using PSCAD/EMTDC (Manitoba Hydro International Ltd., Winnipeg, Manitoba, Canada), a system analysis program package and verified the results depending on the type of faults with the proposed algorithm.

A Novel Driving Scheme for Three-Phase Bearingless Induction Machine with Split Winding

In order to reduce the costs of implementing the radial position control system of a three-phase bearingless machine with split winding, this article proposes a driving method that uses only two phases of the system instead of the three-phase traditional one. It reduces from six to four the number of inverter legs, drivers, sensors, and current controllers necessary to drive and control the system. To justify the proposal, this new power and control configuration was applied to a 250 W machine controlled by a digital signal processor (DSP). The results obtained demonstrated that it is possible to carry out the radial position control through two phases, without loss of performance in relation to the conventional three-phase drive and control system.

Voltage profile improvement and losses minimization for Hayin Rigasa radial network Kaduna using distributed generation

This research work has presented the application of distributed generation (DG) units in a simultaneous placement approach on IEEE 33 radial test systems for validation of the technique with further implementation on 56-Bus Hayin Rigasa feeder. The genetic algorithm (GA) is employed in obtaining the optimal sizes and load loss sensitivity index for locations of the DGs for entire active and reactive power loss reduction. The voltage profile index is computed for each bus of the networks to ascertain the weakest voltage bus of the network before and after DG and circuit breaker allocation. The simultaneous placement approach of the DGs is tested with the IEEE 33-bus test networks and Hayin Rigasa feeder network and the results obtained are confirmed by comparing with the results gotten from separate DGs allocation on the networks. For IEEE 33-bus system, the simultaneous allocation of DGs and of optimal sizes 750 kW, 800 kW and at locations of buses 2 and 6 respectively, lead to a 66.49 % and 68.64 % drop in active and reactive power loss and 3.02 % improvement in voltage profile. For the 56-bus Hayin Rigasa network in Kaduna distribution network, the simultaneous placement of DGs of sizes 1,470 kW and 1490 kW at locations of bus 16 and 23 respectively, lead to a 79.54 % and 73.98 % drop in active and reactive power loss and 15.94 % improvement in voltage profile. From results comparison, it is evident that the allocation of DGs using the combination GA and load loss sensitivity index, gives an improved performance in relations to power loss reduction and voltage profile improvements of networks when compared to without DGs.

Design and planning of a distribution system using renewable technologies in a rural area of Pakistan

The inclusion of renewable energy sources in a distribution system to form a dispersed or decentralized generation network has gained tremendous progress in recent years. The architecture of the distribution system has the potential to serve as a microgrid during an islanding operation connected directly to the load center while excited fully by renewable technologies. This paper deals with planning and designing of a medium voltage power distribution system in a rural area of Pakistan affluent with abundant reserves of renewable sources of electricity. Two types of distribution system architectures, namely radial and ring systems, are simulated using a power flow algorithm with three types of renewable generation technologies: solar, wind, and biogas. The theoretical study involves realistic parameters such as total houses, estimated load, distance of the load from proposed generation site, solar irradiance, wind speed, and biogas reserves. As a result, transformer losses, line losses, power factor, and voltage profile across the load are evaluated for both system types and compared. It is concluded that the ring system maintains better voltage profile, higher power factor, and less transformer and line losses as compared to the radial system. All the relevant construction details together with the electrical and operational parameters of the power system need to be processed accurately in a computer program. Such a program has been modeled as part of this research with embedded methods and conditions outlined in this paper.

Genetic Algorithms and Satin Bowerbird Optimization for optimal allocation of distributed generators in radial system

In this document, the topic of discussion is the combination of two existing algorithms to generate a new hybrid technique. The two algorithms that are subjected to said amalgamation are Genetic Algorithms (GA) and Stain Bowerbird Optimization algorithms (SBO). These two methodologies have profound utility themselves and are used in a multitude of scenarios. The easy application and the constructive outcomes manifested by these two algorithms birthed the idea of their combined usage. Following up on this, the hybrid GASBO was created. GASBO was an optimization approach used to detect and categorize the allotted renewable energy assets in a specific energy generation complex. This was done to regulate the energy dispensing systems otherwise known as ‘distributing’ systems. These renewable resources are reflected by environmental factors and the energy they create is also dependent on their surroundings. Factors like sunlight, rain, waves, and tides etcetera play major roles in determining the outcome of the created energy.Contrary to what it may appear like, the position of the DG sources in the structure affects the outcome a lot. These sources contain fuel cells and photovoltaic cells: in short, devices that can harness energy from a seemingly infinite supply like sunlight. As mentioned before, the GASBO assisted in providing the best location for the system and it also categorized the sources according to their abilities. The potential and position of the sources in the grid are of vast importance. The main purpose of GASBO is to optimize the overall system by improving its efficiency and reducing collateral harm. This shows that GASBO is quite a fundamental tool. It has also been tested on several systems like IEEE 33-bus. The facts in this paper are based on published projects.

Radial shearing speckle pattern interference system based on a spatial light modulator.

We propose a new radial shearing speckle pattern interference system. The introduction of radial shearing and the four-step temporal phase shift are realized using a spatial light modulator to modulate the phase information of the light wavefront. The modulation mode of the spatial light modulator is controlled by programming, and thus the shearing information can be adjusted quickly and arbitrarily according to the actual measurement needs. The interference system no longer has the requirement of the defect direction in nondestructive testing and can simultaneously realize the accurate detection of defects in all directions. The basic principle of radial shearing speckle pattern interferometry and the introduction method of radial shearing are described, and the system feasibility and practicability are verified by experiments.

The Reconfiguration of Network at 20 kV Distribution System Nagan Raya Substation with the Addition of the Krueng Isep Hydroelectric Power Plant

Switching substations are usually supplied from one express feeder which can cause a low level of reliability due to disruption or outage on the express feeder. Also, the lack of power supply at the ends of the network causes voltage drops. One way to solve this problem is to reconfigure the network. In this study, testing was carried out on a distribution system in the Nagan Raya Regency, namely the distribution system of PT. PLN (Persero) ULP Jeuram originally had a radial system. Furthermore, the distribution system was reconfigured with the Krueng Isep hydroelectric power plant which was included in the PLN ULP Jeuram grid so that the system that was originally radial became a loop configuration. The method used in analyzing the network reconfiguration process is to use the ETAP 12.6 application. As a result, after reconfiguring the network the voltage increased from 19.2 kV to 20.7 kV, the highest increase was at the Beutong Substation which reached 1.5 kV and decreased power losses in the network with a total of 188.2 kW and 263.1 kVAR. Furthermore, before the network reconfiguration, ULP Jeuram SAIFI value was 22.25 times/customers and SAIDI values 1337.74 minutes/ customers. However, after reconfiguring the network, ULP Jeuram SAIFI value fell to 15.39 times/customers and SAIDI to 945.6 minutes/customers, resulting in an increase in system reliability by 70.69%. Keyword: Reconfiguration of network, distribution system, hydroelectric power plant, SAIDI, SAIFI

A novel implementation for fractional order capacitor in electrical power system for improving system performance applying marine predator optimization technique

This paper investigates the integration of the fractional-order capacitor on electrical power systems to improve system performance. The system performance problem in this exploration is reducing the losses and improving the voltage profile. For decades, capacitor installation is having a great effect on compensating system reactive power which affects system performance and quality. The novelty in the proposed work is to integrate the fractional capacitor to the power systems as a distributed generator. The study compares the classical capacitor implementation versus the fractional capacitor as a suggested new technology. Due to the complexity of the study to obtain optimal size, parameter, and location of the proposed technologies, Marine predator as a meta-heuristic optimization technique is employed. The proposed methodology can be divided into two parts; a single objective function to study the losses minimization and the voltage improvement individually and the second part is the multi-objective single representation problem to find the optimal solution for both two targets, the losses reduction, and the voltage profile improvement. The proposed fractional capacitor implementation is assimilated to standard IEEE 69 radial system.