Transmission System Research Articles

Observation of multifunctional robust topological states based on asymmetric C4 photonic crystals

Recent advancements in high-order topological insulators have heralded new opportunities for the innovation and utilization of optical devices. This paper presents a composite asymmetric C4 photonic crystal to achieve multifunctional, robust topological states. Through detailed analysis of the fine changes in the topological bandgap induced by distortion parameters, we facilitate the realization of topological edge states in wavelength division multiplexing applications. We utilize both trivial and nontrivial properties of the topological bandgap to precisely manipulate zero-dimensional angular states, one-dimensional topological boundary states, and two-dimensional body states. Through simulations and experimental results, our advanced asymmetric C4 photonic crystal structure demonstrates superior robustness for the transmission of topological edge states. Our research paves the way for the deployment of more robust topological boundary state transmission systems and advances the application potential of higher-order topological states.

2D-convolutional neural network based fault detection and classification of transmission lines using scalogram images

The reliable operation of power transmission systems is essential for maintaining the stability and efficiency of the electrical grid. Rapid and accurate detection of faults in transmission lines is crucial for minimizing downtime and preventing cascading failures. This research presents a novel approach to fault detection and classification in transmission lines employing 2D Convolutional Neural Networks (2D-CNN).The proposed methodology leverages the inherent spatial characteristics of fault signals, converting them as 2D scalogram images for input to the CNN model. By converting fault signals into scalogram representations, the network can capture both temporal and frequency domain features, enabling a more comprehensive analysis of fault patterns. The 2D-CNN architecture is designed to automatically learn hierarchical features, allowing for effective discrimination between different fault types. To evaluate the performance of the proposed approach, extensive simulations and experiments were conducted using MATLAB/SIMULINK modeled transmission line data. The results demonstrate the superior fault detection accuracy and classification capabilities of the 2D-CNN model. The performance of the proposed model is evaluated using 10-fold cross-validation, and its effectiveness is assessed by comparing it with current state-of-the-art techniques. Proposed 2D-CNN model has evidenced an accuracy of 99.9074 with ideal dataset for 12- class fault classification and performing consistently in presence of noise, having an accuracy of 99.629 %,99.72 % and 99.814 % in 20.30 and 40 dB noises respectively. The proposed model also verified in high resistance fault condition. The model exhibits robustness to noise and is capable of generalizing well to various fault scenarios. The proposed methodology offers a scalable and efficient solution for transmission line fault analysis, paving the way for the integration of advanced machine learning techniques into the operation and maintenance of power transmission infrastructure.

Event-Based Distributed Finite-Time Secondary Control for Multiterminal DC Transmission Systems: Restores Average Voltage and Achieves Power Sharing

Event-Based Distributed Finite-Time Secondary Control for Multiterminal DC Transmission Systems: Restores Average Voltage and Achieves Power Sharing

Resilient and Fast Block Transmission System for Scalable Hyperledger Fabric Blockchain in Multi-Cloud Environments

Resilient and Fast Block Transmission System for Scalable Hyperledger Fabric Blockchain in Multi-Cloud Environments

Active Inertia Extended Resonance Ratio Control for Permanent Magnetic Coupling Transmission System

Active Inertia Extended Resonance Ratio Control for Permanent Magnetic Coupling Transmission System

RANCANG BANGUN TRANSMIS MESIN PERONTOK 3600 RPM BERBASIS MOTOR BENSIN

A rice threshing machine is the process of separating rice from its stems, so that reducing rice agricultural yields is very strategic in supporting rice production. Modification of the tool which previously used a slamming system, resulted in the yield of grain containing quite high levels of grain. The aim of this research is to design the transmission rotation to make the belt pulley and shaft more effective. The rice threshing machine transmission system consists of a pulley and belt with various belt sizes. The appearance of the pulley for calculations is adjusted to a pulley size of 10 inches = 25.4cm. Then the belt that connects the 10 inch/25.4cm pulley and the 9.74cm A58 belt is the belt that connects the pulley and the shaft. Based on the results of transmission performance testing with power and planning moment of 5.8164 kW and pulley planning moment of 1573.65 kg.mm from type A, the calculation of driver pulley rotation = 3 inches (d1) and motor rotation = 3600 rpm (n1) can be used rpm of the drive pulley when it is not loaded and when working, namely the rpm of the drive pulley when it is not loaded is 1080 rpm. Furthermore, the pulley rpm when working is 9.75\ rpm\ and\ The design power of the shaft is 4.92\ for the shear stress that occurs on the shaft of 0.838 kg/mm which is smaller than the allowable shear stress with a value of 5.16 kg/mm. so that the power and moment of planning the shaft with a diameter that can be used safely.

Numerička analiza titrajnog odziva dalekovoda velikog raspona prijenosnih vodova izazvanog vjetrom

Based on the engineering background related to ±800 kV ultra-high voltage (UHV) transmission lines spanning the Yellow River, finite element models were developed for single-tower and transmission tower-line systems, with their wind-induced responses under wind loads were simulated and analysed. In addition, the coupling effect in a large-span transmission tower line system was investigated. The results showed that the natural vibration frequency of the tower-line system was slightly lower than that of a single tower and that the torsional natural frequency was the most significantly reduced. The transmission tower-line system has a maximum displacement of 1.92 times that of a single tower when the wind angle is 0°. The maximum axial force and stress in the tower-line system are 1.6 times and 1.37 times higher than those in a single tower. The interaction between the tower and wires significantly affects the wind-induced response of the tower body. Hence, considering the dynamic coupling effect of the tower-line transmission system is important when designing a tower.

All-optical combinational logical units featuring fifth-order cascade

Modern computational technologies are increasingly encountering significant limitations, driving a shift towards alternative paradigms such as optical computing. In this study, we introduce novel all-optical combinational logic units based on diffractive neural networks (D2NNs), designed to perform high-order logical operations both efficiently and swiftly using only two modulation layers. This innovative design offers increased processing speed, improved energy efficiency, robust environmental stability, and high error tolerance, making it exceptionally well-suited for a broad spectrum of applications in optical computing and communications. By leveraging transfer learning, we successfully developed a fifth-order cascaded combinational logic circuit for practical information transmission system. Furthermore, we reveal a pioneering application of our device in Optical Time Division Multiplexing (OTDM), demonstrating its capability to manage high-speed data transfer seamlessly without the need for electronic conversion. Extensive simulations and experimental validations highlight the potential of our model as a foundational technology for future optical computing architectures, paving the way toward more sustainable and efficient optical data processing platforms.

Reactive Power Compensation for Standalone Hybrid Power System Using Facts Devices

Reactive power compensation is essential in hybrid grid-connected systems because power electronic inverters utilized for supplying DC energy into the grid causes a reduction in the overall power factor of the power systems. Due to the ability to provide a reliable and efficient power supply to remote and off-grid areas, hybrid power systems are growing in popularity. It can provide greater opportunities for operational growth by combining economic and technology advancement. To meet the demand for electrical energy in both regular and critical situations, operators must be in charge of the power systems reliable and secure operation. The primary objective of the work is to control the reactive power flow in a grid-connected hybrid renewable energy system (PV-wind-battery). The power quality problems that these systems frequently experience include voltage sags, harmonics, and flicker. A FACTS device Unified Power Quality controller (UPQC) with a Genetic Algorithm based PI controller is suggested to handle these power quality issues. In order to improve the performance of the power system, the proposed optimization approaches are used to tune the UPQC in a multiline transmission system. The model was developed with the help of the MATLAB/Simulink work framework.

Heterogeneous radio frequency/underwater optical wireless communication relaying systems with MIMO scheme

This paper studies a cooperative relay transmission system within the framework of Multiple-Input Multiple-Output Radio Frequency/Underwater Optical Wireless Communication (MIMO-RF/UOWC), aiming to establish sea-based heterogeneous networks. In this setup, the RF links obey κ-μ fading, while the UOWC links undergo the generalized Gamma fading with the pointing error impairments. The relay operates under an Amplify-and-Forward (AF) protocol. Additionally, the attenuation caused by the Absorption and Scattering (AaS) is considered in UOWC links. The work yields precise results for the Average Channel Capacity (ACC), Outage Probability (OP), and average Bit Error Rate (BER). Furthermore, to reveal deeper insights, bounds on the ACC and asymptotic results for the OP and average BER are derived. The findings highlight the superior performance of MIMO-RF/UOWC AF systems compared to Single-Input-Single-Output (SISO)-RF/UOWC AF systems. Various factors affecting the Diversity Gain (DG) of the MIMO-RF/UOWC AF system include the number of antennas/apertures, fading parameters of both links, and pointing error parameters. Moreover, while an increase in the AaS effect can result in significant attenuation, it does not determine the achievable DG of the proposed MIMO-RF/UOWC AF relaying system.

A nonlinear hysteresis compensation control of hydro-viscous drive in air transport operations

The Hydro-Viscous Drive (HVD) speed regulating system finds extensive application in air transport transmission systems to regulate the stepless speed or conduct overload protection. However, its intrinsic hysteretic behaviors, such as the asymmetric hysteretic and dead zone, could introduce inaccuracy and delay in control applications, posing challenges to system regulation. This paper investigates a Nonlinear Hysteresis Compensation Control (NHCC) that consists of two parts to control the HVD output speed by operating the valve under different engine operating conditions. In the first part, the Inverse Hysteresis Compensator (IHC) based on major loop data is introduced for the asymmetric hysteresis characterization and compensation of the HVD speed control system of the power generation and distribution, which aims to reduce the hysteresis and dead zone effect and expand the effective input range. In the second part, the Active Disturbance Rejection Controller (ADRC) is employed to mitigate the hysteresis effects of the compensated system and remove the steady-state error, which allows real-time compensation of the estimated perturbations as state feedback to achieve the required performance. An experimental laboratory station has been fabricated to evaluate the proposed method. The test results show that the NHCC method can regulate the fan speed to the desired value (|e|< 45 r/min at steady state) and broaden the effective input range to the full range under different engine conditions. Besides, the proposed control method can reduce the non-linearity of the input and output curves (from 18% to 4%) and compensate for the asymmetric hysteresis (from 38% to 5%).

Principle and pressure loss experiment of electro-hydraulic slide-rotary direction valve in single-pump and multi-motor hydraulic system

To better realize direction control of the single-pump double-motor hydraulic system and simplify the system, structure and principle of a six-position six-way direction control valve was proposed, which the valve spool has two motion modes: sliding and rotating. Using this valve, the inner and outer motors can work independently and simultaneously. The pressure loss of the valve was tested by building a transmission system, and the experiment results were compared with theoretical analysis. The results show that the performance of the valve working in left and right positions is better than that in meso-position, and the maximum pressure loss occurred in meso-position. Under the rated flow, the maximum pressure loss is 0.331 MPa. Then the characteristic curve of flow-pressure loss and the relationship of pressure loss among oil ports are obtained. In the same conditions, except that the oil inlet pressure loss in the meso-position is greater than the oil outlet pressure loss, the oil inlet pressure loss in the left and right positions are less than the oil outlet pressure loss, the pressure loss in the forward position is less than the pressure loss in the reverse position. The experiment verifies the correctness and feasibility of the structure and principle.

Field trial of stable radio frequency transfer system in 200 km metropolitan optical fiber link.

In this paper, we demonstrate stable radio frequency (RF) transfer via metropolitan optical fiber link in the Beijing area. The phase variation of the RF signal is compensated by a phase conjugation method incorporating two high-performance phase-locked loops. The wavelength conversion module extends the transmission length to 200 km with only two parallel 50 km dark optical fibers available. We optimize the configuration of dispersion compensation and optical amplification due to the high loss (0.31 dB/km) of the optical fiber link. At the same time, comparative experiments verify the short-term instability limitation that arises from the group velocity dispersion of the optical fiber link. The measured standard Allan deviation of the 2.4GHz RF transmission system with dispersion compensation is 4.5 × 10-14/1 and 2.6 × 10-17/20 000s, which is superior to that of the reference rubidium clock. The short-term instability of the system is deteriorated to 2.5 × 10-13/1s without dispersion compensation.

Rigid-flexible coupling dynamic-assisted imbalanced fault diagnosis for helicopter tail transmission system

Helicopters operate in extreme environments, complicating the balanced and accurate acquisition of operational data. Predicting high-precision failures in helicopter tail-drive systems is particularly challenging due to severe data imbalances. To address this, a fault diagnosis method based on rigid-flexible coupling dynamics is proposed. A high-precision simulation model generates source domain data samples, validated by comparing the frequency domain components and RMS values of simulated and tested vibration responses under healthy conditions. An adaptive Local Maximum Mean Discrepancy (LMMD) mechanism aligns features between simulated and tested data. Additionally, the Coordinate-Separable Convolutional ResNet (CSC-ResNet) network is proposed to efficiently learn high-dimensional feature knowledge. Results show the proposed method outperforms others in fault diagnosis accuracy and smoothness, offering a new perspective for fault diagnosis of helicopter tail transmission systems.

Experimental and numerical studies on the propagation paths of gear root cracks

Gear bending fatigue failure has a significant impact on the operational performance of advanced machinery, such as electric vehicles and wind turbines, potentially leading to failures and catastrophic consequences for transmission systems. Several methods are currently used to predict gear crack propagation; however, a comprehensive comparison of their accuracy and efficiency in predicting crack paths is lacking. In this study, the propagation path of root cracks in commonly used automotive gears was investigated using finite element (FE) analysis and experimental testing. Three mixed crack path prediction criteria were integrated to predict the gear root crack propagation using the commercial software ABAQUS by user-defined Python script. The impacts of gear crack parameters, including the gear initial crack length, on gear root crack propagation behaviour were analysed. The simulations were verified by the gear bending fatigue test using a single tooth bending test device. The results indicate that the simulation outcomes align with the experimental tests, demonstrating that all three criteria are effective in predicting gear root crack propagation behaviours.

Perancangan Perancangan Sistem Trasmisi Mesin Pres Hidrolik Kapasitas 3 Ton Dengan Penggerak Motor listrik

Technological advances have encouraged improvements in the industrial sector in developing countries, including Indonesia. This is of course supported by several factors, including the use of modern equipment as a substitute for human labor. It can be said here that the more modern an industry is, the more machine power is used while the less human power is needed. As human needs become increasingly greater, the machine industry is currently also developing very rapidly. Developments in the industrial sector are marked by the creation of various types of machines that can assist human activities. The use of machines can help human activities or work to be more efficient in terms of completion time, as well as reducing the risk of work accidents. Currently, machines are used as tools that have high automation and precision. Therefore, many people use machines for everything, one of which is a pressing machine. A pressing machine is a tool made to compress or press an object, the power source can come from hydraulics, human power, electric motors and others. The aim of this final project is to design a transmission system for a 3 Ton Semi-Automatic Hydraulic Press Machine with an electric motor drive. It can increase the author's knowledge, insight and experience regarding planning a machine. Conclusion Ball bearings with type 6203 require an installation time of 1 minute 35 seconds and removal of 1 minute 32 seconds. Ball bearings of type 6305 receive a pressure of 400 psi to be installed on the shaft, and when released the pressure produced is the same, namely 400 psi to be able to leave the shaft. A type 6206 ball bearing with a shaft length of 77 mm takes 3 minutes 32 seconds to install, while the same shaft length takes 3 minutes 22 seconds to remove from the shaft.

A 2.4-7GHz Dual Band Microstrip Patch Antenna (DBMPA)

We designed a 2.4-7GHz dual-band microstrip patch antenna DB-MPA using electromagnetic field simulation and transmission characteristic (S21) measurements. Optimizing the slot length of the patch surface increased the directional antenna gain at 7 GHz by 3.5 dB compared to 2.48 GHz, reducing the effect of the higher spatial propagation loss of 9 dB at 7 GHz. A transmission system simulation with an antenna component model incorporating S21 data measured with the 2.4-7GHz DB-MPA from 1 to 8 GHz was conducted at a spatial propagation distance of 5 to 40 m to verify the practicality of the 2.4-7GHz DB-MPA

REVIEW OF PARAMETERS INFLUENCING WIRELESS ENERGY TRANSMISSION BY MAGNETIC INDUCTION

In this review article, we present a detailed study and discussion of wireless energy transfer systems based on studies in the literature, with the help of Python programming software. Starting from the basic element of wireless transmission by magnetic induction, i.e. the coil, through a magnetostatic study we have highlighted the impact of geometry, coil misalignment and coil loss factors on these transmission systems. We have also shown that parameters such as coupling coefficient and frequency can improve transmitted power and efficiency. A summary of the latest research in this field will also be given.

The Design of a Long-Distance Signal Transmission System in a Bistatic RCS Testing System

In wireless communication and radar systems, long-distance signal transmission poses significant challenges that affect overall system performance. In this paper, we propose an innovative bistatic radar cross section (RCS) testing system designed to address these challenges, with a particular focus on its long-distance signal transmission capabilities. This system is capable of accurately measuring the RCS of a target and improving multipath channel modeling accuracy by using precise RCS values. The integrated upper computer software extracts amplitude and phase information from received echo signals, processes these data, and provides detailed outputs including the target’s RCS, one-dimensional image, and two-dimensional image. The experimental results obtained prove that this system can not only achieve effective long-distance signal transmission but also substantially enhance the accuracy of RCS measurements, offering reliable support for multipath channel modeling. However, the conclusions drawn are preliminary and require further experimental validation to fully substantiate this system’s performance. Future work will focus on improving system accuracy, minimizing the impact of environmental noise, and optimizing data-processing methods to enhance the efficiency of wireless communication and radar applications.

Analysis of Reactive Power Flow in an Electric Power System

Optimal power flow analysis is a calculation to minimize an objective function, namely generation costs or transmission losses by regulating the active power and reactive power generation of each interconnected power system generator by taking into account certain limits. The growth of industrial loads which are dominated by inductive loads requires a fairly large reactive power supply. This reactive power requirement will of course reduce the available power that can be transmitted to the load. Reactive power flow in transmission lines will reduce the active power distribution capacity required by the load. Reactive power flow that is too large can also cause losses. However, this reactive power is also an important component in the stability of the electric power system. For this reason, the flow of active and reactive power in transmission lines needs to be regulated so that the capacity and stability of the electric power transmission system is maintained.