Power Supply Equipment Research Articles

Optimal power dispatch method for wind farms considering service quality and available power

AbstractThis paper proposes an active and reactive power dispatch method for a wind farms (WF) considering the real‐time service quality and the available power to achieve the fair power allocation within the WF. The goal is to ensure operational safety while meeting the power demand instructions from the dispatch centre. This paper generates WF service quality metrics based on real‐time monitoring data of key components to characterize the operational stability of the wind turbines (WTs). Specifically, service quality metrics related to active/reactive power are constructed separately to improve the accuracy of service quality assessment and power dispatch. The available power is then integrated into the service quality metrics to derive active/reactive power allocation factors, considering operational safety and power margin. Active power allocation is constrained by the power demand instructions, while reactive power allocation aims to maintain the WT terminal voltage within a feasible range. The proposed method can ensure the fair power allocation within WFs to meet the requirements of equipment reliability, voltage safety, and power supply simultaneously, which can improve resource utilization and avoid the potential failure. Case studies in MATLAB/Simulink confirm the effectiveness of the proposed method.

Day-ahead optimal dispatch method of integrated electric-heat-cool-gas energy system based on N-1 safety criterion

With the continuous development of integrated energy system and the deepening of the coupling relationship between multiple energy flows, the safe and stable operation of the system has received widespread attention. At present, the security of integrated energy system is mostly researched from the perspective of power grid and rarely researched from the perspective of equipment. This study proposes a day-ahead optimal dispatch method of integrated electric-heat-cool-gas energy system based on N-1 safety criterion, which ensures the normal operation of integrated energy system after the failure of a power supply equipment by increasing appropriate amount of power supply. In this study, the changes in equipment power and operating cost before and after equipment failure under the dispatch method considering N-1 safety criterion and the changes in equipment power and operating cost before and after equipment failure under the dispatch method without considering N-1 safety criterion are investigated by numerical simulation. The results show that when a power supply equipment fails, the average daily loss of load is 6139.99 kW for the dispatch method without considering the N-1 safety criterion and the average daily loss of load is 0 kW for the dispatch method considering the N-1 safety criterion. Therefore, the dispatch method considering the N-1 safety criterion performs better in terms of reliability. When a power supply equipment fails, the average operating cost is 5127.71 USD for the dispatch method without considering the N-1 safety criterion and the average operating cost is 4125.56 USD for the dispatch method considering the N-1 safety criterion. Therefore, the dispatch method considering the N-1 safety criterion performs better in terms of economy.

Calculation of the main operational characteristics of a tethered high-altitude ship-based system

Objectives. Currently, UAVs are actively used in many military and civilian fields such as object surveillance, telecommunications, radar, photography, video recording, and mapping, etc. The main disadvantage of autonomous UAVs is their limited operating time. The long-term operation of UAVs on ships can be ensured by tethered high-altitude systems in which the power supply of engines and equipment is provided from the onboard energy source through a thin cable tether. This paper aims to select and justify the appearance of such system, as well as to calculate the required performance characteristics.Methods. The study used methods of systemic and functional analysis of tethered system parameters, as well as methods and models of the theory of relations and measurement.Results. The issues of design and implementation of new generation tethered high-altitude ship-based systems were considered. A rational type of aerodynamic design for unmanned aerial vehicles was determined based on existing tethered platforms. The optimal architecture of the tethered system was defined and justified. The paper presents the appearance and solution for placement onboard the ship, and describes its operation. The main initial parameters for designing high-altitude systems such as take-off weight, optimal lift altitude, maximum power required for operation, structure of the energy transfer system, as well as deployment and lift time to the design altitude were selected and calculated.Conclusions. The methodology for calculating the necessary characteristics described in the paper can be used for developing and evaluating tethered high-altitude systems. These systems are capable of performing a wide range of tasks, without requiring a separate storage and launch location, which is especially important in the ship environment. The system presented herein possesses significant advantages over well-known analogues.

Prospects for the development of charger-discharge devices of spacecraft power supply systems

Power supply system (PSS) is designed to ensure uninterrupted autonomous power supply of on-board equipment in all modes and at all stages during the active life of spacecraft. Lots of PSS makes up a significant proportion of the mass spacecraft and improvement of specific energy characteristics PSS this leads to a synergistic effect when the mass and energy consumption resources available for the payload are simultaneously increased, which increases efficiency of spacecraft generally. The article considers the evolution of structural and circuit solutions for PSS spacecraft, its energy-converting equipment and the effect of these changes on energy-mass characteristics PSS. It is shown that a significant effect on energy and mass characteristics PSS provide structural and circuit design solutions for charger and discharge devices of energy-converting equipment and the choice of voltage value accumulator batteries (AB). The development of the element base, the creation of programmable digital devices capable of functioning under the influence of space factors and the emergence of new circuit design and management solutions for pulse converters that have occurred in the last decade opens up new opportunities for improvement of the PSS of spacecraft. In the article as a charger and discharge device PSS reviewed pulse voltage converter (PVC) with a new modulation strategy, with the ability to reverse the flow of energy and the ability to work in a step-up mode with high efficiency. Its application as a single charger-discharge device (CDD) allows for a significant improvement in performance CDD and PSS in general, such as efficiency, energy mass, reliability and a number of others. Ability PVC to reverse the flow of energy and the possibility of working in a step-up mode opens up the possibility to abandon the use of AB with a voltage lower than the voltage at the main output PSS and switch to using AB with an average discharge voltage close to the voltage at the main output PSS. Such a structural and circuit design solution CDD and AB will allow you to increase efficiency of CDD up to 99 % and additionally improve energy and mass characteristics PSS.

Recent Progress on Built-in Wave Energy Converters: A Review

A built-in wave energy converter (BI-WEC) is a type of WEC that is fully encapsulated within a floating body that is easy to integrate and promotes reliability. Significant advantages in integration and reliability make BI-WECs a promising pathway to achieve an in situ power supply for massive distributed marine equipment (such as ships, buoys, or USVs). A comprehensive review of the recent advances in built-in wave energy converters can help address the most relevant issues in BI-WEC development. This study enumerates recent progress on BI-WECs (energy capture, power take-off, and control) and summarizes the characteristics of various designs. Different design philosophies and technical pathways can be better understood through the classification and analysis offered by this study. This review helps to form a basic understanding of BI-WEC development to achieve in situ power sustainability for a large amount of distributed marine equipment in long-term sustained marine operations.

Study on the Design of Valve Base Insulation and Power Supply Transformer for High-Voltage DC Circuit Breaker

Abstract High-voltage DC circuit breaker is a key piece of equipment to building DC power grids. DC circuit breakers need to support and isolate from high voltage to ground through valve-based equipment and use valve-based power supply transformer to continuously supply energy to high potential components, the electrical performance of these two equipment determines whether DC circuit breakers and DC networks can be operated safely and reliably. For this reason, this paper carries out the research on the insulation capability of the valve base and the performance of the power supply transformer, such as the design and simulation of electric and thermal fields, as well as the test program. Firstly, the insulation design and simulation study of the valve base as a whole is carried out, and the design optimization of the equipotential scheme of the top homogeneous tubular bus, diagonal pull insulator and hydroelectric pole is completed. Secondly, the design and simulation verification of the thermal field distribution of the energy-supply transformer, the overvoltage between the ends of the output windings and the optimization scheme, and the short-circuit impedance were carried out. Finally, the insulation performance of the valve base, the temperature rise of the energy supply transformer, the overvoltage simulation of the output winding and the short-circuit characteristics were tested. The results show that: after optimization, the maximum field strength of the homogenizer is 2.3kV/mm, and the overall maximum field strength of the valve base is 2.61 kV/mm on the diagonal insulator, and there is no pressure difference between the water circuit and the fittings using the three-pin vertically distributed hydropower electrode scheme; the temperature rise of the supply transformer in the simulation and the actual measurement is 27K and less than 30K; by means of the parallel connection of the MOV, the overvoltage of the output winding of the power supply transformer under voltage impulse is effectively reduced to -1.8kV; the measured short-circuit impedance of the power supply transformer is 69.5%. The optimized design of DC circuit breaker valve base and power supply transformer can operate safely, and effectively support the construction of DC circuit breaker and DC power network.

Design of voltage and frequency stabilization system for fishing vessel shaft generator based on UPS backup power supply

Abstract A fishing boat shaft generator is a kind of power supply device driven by the main diesel engine, which has the advantage of saving energy compared with a diesel generator and eliminating the need to be equipped with an additional diesel engine, witnessing wide applications in the use of power supply equipment for fishing boats. However, because the shaft generator is mounted on the main diesel engine, the fishing boat encounters bad sea conditions at sea, and the speed of the diesel engine fluctuates, resulting in the instability of the power frequency and voltage sent by the shaft generator, which will endanger the electrical equipment of the fishing vessel in serious cases. In this paper, a design of a voltage and frequency stabilization system for a fishing vessel shaft generator based on a UPS backup power supply was proposed. The system consists of a three-phase shaft generator, inverter, battery, and electrical equipment. The inverter control strategy is introduced, and the battery charge/discharge and DC boost are designed.

Design and Experimental Research of a Lifting-Type Tidal Energy Capture Device

In this study, in order to promote the development of far-reaching marine aquaculture equipment in an intelligent direction and solve the problems related to power supply, a tidal current energy harvesting device for a low-velocity sea area is proposed. For low-velocity waters in farming areas, the device can effectively harness tidal energy to provide a stable power supply to open sea cages. A mathematical model of the Savonius turbine blade is established, and the influence of the distance between the impeller center and the water surface on the energy capture efficiency of the turbine is analyzed through numerical simulation. Using ANSYS2021R1 software, the velocity field of the floating body is simulated, and the overall structure and anchoring system of the power generation device is designed. In order to verify the effectiveness of the power generation device, a test model is built and a physical model test is carried out. The variation in parameters related to the relative distance between the impeller and the water under different flow velocities is tested, and the test data are analyzed. The test results show that the floating body can increase the flow speed by 10%. Optimizing the blade number and order of the S-turbine can capture more than 20% of the energy. Under different flow velocities, the capture power of the impeller first increases and then decreases with increasing distance from the water. When the center of the impeller is one-quarter of the impeller diameter higher than the water surface, the output power of the impeller is at the maximum. This indicates that the proposed power generation device can effectively use tidal energy under different water depth conditions and provide a stable power supply for far-reaching marine aquaculture equipment.

Research on the Effects of Voltage Sags and Harmonics on the Output Characteristics of Switching Power Supply

Switching power supply is widely used in industrial equipment, household appliances, and other fields due to the advantages of high integration and lightweight. Voltage sags can seriously affect the output voltage of switching power supply and the working condition of its power supply equipment; at the same time, the working scenarios of power equipment using switching power supply often have different level of harmonic problems. Considering the continuous innovation of switching power supply technology, the previous analysis and test results on the effect of voltage sags and harmonics on switching power supplies may no longer be applicable. The paper reveals the mechanism of the effect of harmonic alone as well as voltage sag superimposed harmonics on the output voltage of the switching power supply. Then the test research program was developed, and four different brands switching power supplies were selected for the test research, with which the effects of different amplitude voltage sags, harmonics with different frequencies and distortion, as well as voltage sag superimposed harmonics on the output voltage of switching power supplies were investigated. The results show that the tolerance ability of switching power supplies to voltage sags has been improved compared with previous switching power supplies, and the harmonic itself has less effect on the output voltage of switching power supply, but the joint action of harmonics and voltage sags will have a greater effect on the output voltage of switching power supply. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

400 watt Solar Power Generation System (PLTS) as a Power Supply for Information Equipment

Panel surya merupakan salah satu energi alternatif yang dapat diperbarui yang dapat digunakan menjadi energi primer dalam membangkitkan energi listik melalui sistem Pembangkit Listrik Tenaga Surya (PLTS). Bahan utama PLTS adalah radiasi yang dihasilkan matahari setiap harinya. Sedangkan energi listrik merupakan kebutuhan primer masyarakat modern, dengan mulai menipisnya sumber energi fosil muncul permasalahan terjadinya krisis energy listrik. Oleh karena itu diperlukan adanya, energi terbarukan menjadi solusi, sebagai pembangkitan listrik tenaga surya sesuai dengan potensi alam di Indonesia yang mencukupi. Sistem pembangkitan listrik tenaga surya (PLTS), berkapasitas 500 watt, sangat cocok dipasang untuk catu daya pada setiap kebutuhan di masyarakat, dengan panel surya 2x100 Wp, solar charger controller 12 Volt - 10 Amper dan baterai deepcycle berkapasitas 100 Ah. Analisis dari sistem PLTS dilapangan akan dilakukan berdasarkan pengujian secara langsung sehingga dapat mengetahui kinerja dari peralatan. Hasil sistem pemasangan PLTS bertujuan untuk mengoprasikan peralatan sistem informasi yang terdiri dari peralatan amplifier dan pengeras suara sebagai sarana aktivitas masyarakat.Data potensi penyinaran matahari di Jogjakarta mencapai rata-rata 7 jam/hari. Nilai pengkuran tegangan tertinggi 18,73 volt dan arus 4,52 amper, dengan intensitas cahaya yang diserap mencapai 110.966 Lux pada cuaca cerah dan nilai terendah mencapai 3.407 Lux. Besar iradiasi matahari yang diterima berbanding lurus dengan besar intensitas cahaya matahari yang dihasilkan dengan besar radiasi terbesar mencapai 877 W/m2 sedangkan radiasi terendah sebesar 27 W/m2. Daya rata – rata panel surya yang dihasilkan mencapai 371,07 watt dan besarnya effisiensi konversi sebesar 97%. Daya charger dari peralatan solar charger controller jenis PWM memiliki rata – rata 227,44 watt dan daya total discharger beban sebesar 167.96 watt memiliki hasil effsiensi 89%.

Outside-to-inside: Efficacy comparation of Mn bulk and surface-doped TiO2{201} in E-fueled solar flow battery system

The all-in-one E-fueled solar flow battery system that can be recharged with liquid fuel is a new type of power system. It can continuously convert solar energy into liquid fuel without relying on external power supply equipments. However, the interface between the photoanode and the electrolyte often exhibits unsteady behavior, resulting in poor performance of the system. In this work, the {201} facets are selected and the impact of two doping treatment strategies for TiO2 {201} photoanode on the performance of the E-fueled solar flow battery system is systematically studied through the I-t curve, linear sweep voltammetry, Mott-Schottky plot. The results show that the un-biased photocharging current of bulk-doped TiO2 can reach 2.7 mA·cm−2 in the battery system test, only relying on the self-built electric field at the interface, and the energy conversion efficiency approaches 2.67 %. In addition, the performance is analyzed by the combination of transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and other characterizations, with the aim of distinguishing the effects of bulk- and surface-doped Mn and accurately revealing the mechanism of their influences from the outside to the inside. Finally, the optimization rules of the un-biased light charging mode of the system are explored.

Design of power supply system for portable aviation inspection equipment

Given that airborne electronic equipment may have a variety of wiring methods and may encounter a set of systems using multiple power supplies, it is necessary to take some measures on the circuit to ensure the normal work of the power supply and the post-circuit. A portable aviation detection equipment power supply system is designed in this paper. The system supports simultaneous access of two power supplies to identify and judge the input power supply and switch between the battery and the external power supply, effectively avoiding the security risks caused by battery backflow current. The battery power is monitored in real-time through the battery power detection circuit and will be reminded when the battery power is too low. Since the circuit uses a MOS tube to control the switching of the power supply, there is almost no voltage drop loss. In addition, the EMC protection circuit is set up at the power supply side to further improve the safety and reliability of the system.

Design of passive filter based on magnetic integrated technology for single‐phase grid‐connected inverter

AbstractIn response to the need for smaller and lighter power supply equipment, there has been a push towards higher power density in current power electronic converters. This development aligns well with the requirements of photovoltaic grid‐connected inverters. Among various passive filters utilized in these inverters, the LCL filter stands out as a popular choice. Nevertheless, it should be noted that traditional LCL filters have limited core utilization and exhibit significant redundancy. In view of the above problems, this paper proposes a magnetic integrated passive filter based on ripple transfer technology and carries out volume optimization design. Compared to the conventional LCL filter, the magnetic integrated passive filter offers a reduction in size and weight while preserving its capability to ripples attenuate. Finally, a laboratory prototype with a rated power of 2 kW is built to verify the effectiveness of the proposed magnetic integrated passive filter.

Enhancing technical solutions to reduce fuel energy consumption of drilling equipment during well drilling with air cleaning

Efficient fuel and energy resource utilization in drilling equipment can be attained through strategies such as decreasing the relative consumption in technological systems during well drilling, enhancing the integration of secondary energy resources in the equipment's power supply system, and refining the design of drilling equipment and technologies. This article showcases the outcomes of pilot studies conducted on a diesel power plant within a drilling rig and a device designed for recycling secondary energy resources from a compressor.

Nanosheet Zinc Oxide Synthesized by Solution-Immersion Method for Triboelectric Nanogenerator

Most global problems are being solved by using sustainable energy harvesting technologies to retain the social ecosystem in great condition. The triboelectric nanogenerator (TENG) which is a renewable energy harvesting device, collects the waste mechanical energy from its surroundings and performs the electric signal conversion. TENG have garnered increased attention in recent years by offering prospective use in energy harvesting technology. Particularly, there is a need for flexible energy conversion that serves as a power supply for portable electronic equipment. In this study, ZnO nanosheet thin film prepared on the flexible conductive aluminium foil through a low temperature immersion technique was used to generate electrical energy. The effect of heat treatment on ZnO nanosheet thin film was also investigated on the surface morphology, strutural properties and nanogerator performance. The high density of interconnected ZnO nanosheet were observed before and after heat treatment as confirmed by FESEM studies. The analysis using XRD confirmed that ZnO nanosheet thin film was successfully deposited on the aluminium foil. Additionally, the ZnO nanosheet thin films improved significantly with heat treatment, enhancing their crystalline quality. The triboelectric nanogenerator (TENG) was successfully constructed in contact and separation mode using Kapton tape on top and ZnO nanosheet thin film on the bottom to generate electricity by a force of hand pressing. The output electrical voltage of the device doubled from around 2 V to 4 V after underwent the heat treatment. This study provides an essential insight into fabrication of TENG using the ZnO nanosheet thin film through a clean and effective method for nanogenerator applications.

Generation Coordination and Planning of New Power System Considering Industry Hydrogen Load

Considering the impact of industrial hydrogen load on the consumptive capacity of new energy, it is necessary to research the generation coordination and planning of new power systems considering industry hydrogen load. Firstly, considering the energy consumption in the hydrogen production and storage process, as well as the energy storage for hydrogen addition/use, hydrogen load transfer, and interruptible flexibility, an equivalent electrical load conversion model for multiple forms of hydrogen loads is established. Secondly, considering the impact of industrial hydrogen load on the absorption capacity of new energy, the investment decision-making problem of power supply, hydrogen production, and storage equipment is unified with the operation simulation problem of the system at the planning level, to minimize the annual cost of the system. To reduce the complexity of the model, the proposed model plan to the expansion capacity of various types of power sources from the perspective of power types. Finally, by using actual data from a power grid in a certain province as an example, the results verified the rationality and effectiveness of the model compared with the power grid planning without hydrogen load.

A Web-based coordinated control platform for source-grid-load-storage of low-voltage stations

In order to improve the analysis and control ability of power consumption in the station area, a load storage analysis and control platform based on the Django Web framework is built. The platform takes real-time data acquisition, analysis, and optimal scheduling as the core to realize the comprehensive management and control of power supply, load, and energy storage equipment in the station area. The browser/server (B/S) mode is adopted to support a variety of interactive operations. The energy data, analysis results, and control status of the station area can be viewed intuitively. The Django Web framework is used to realize the extensible design. The analysis and control of the station area are realized by calling the optimization algorithm. Based on Bootstrap, the responsive layout is realized to improve the availability and accessibility of the platform. The graphics are drawn on the platform through Canvas technology, and the interaction and visualization effects are realized.

Power supply station equipment status monitoring and evaluation system based on wireless network technology

With the continuous development of the power industry and the acceleration of the process of intelligence, monitoring and analyzing the status of power supply equipment is crucial for ensuring power supply and safety. Traditional power monitoring systems still have certain problems in data transmission. Using wireless network technology (WNT) to detect and analyze the status of power supply station equipment can not only achieve real-time monitoring and remote control, improve equipment operation and management efficiency, but also achieve automated monitoring and analysis of equipment status, providing technical support for the intelligence of power supply station equipment. In order to verify the effectiveness of the WNT-based power supply station equipment status monitoring and analysis system, a comparative experiment was conducted with traditional wired network monitoring methods. The final experimental results show that the average feedback time for testing the WNT power supply station equipment status monitoring and analysis system is 7.71 s, which is 38.22 s shorter than traditional methods. The average fault location accuracy is 95.98 %, which is 35.91 % higher than traditional methods. The average management efficiency is 92.88 %, which is 34.71 % higher than traditional methods. Through testing data, it can be concluded that the power supply station equipment status monitoring and analysis system based on WNT has greater advantages than traditional power equipment monitoring methods.

Inhibiting scar formation via wearable multilayer stacked electret patch: Self‐creation of persistent and customizable DC electric field for fibrogenic activity restriction

AbstractElectrical stimulation has recently received attention as noninvasive treatment in skin wound healing with its outstanding biological property for clinical setting. However, the complexity of equipment for applying appropriate electrical stimulation remains an ongoing challenge. Here, we proposed a strategy for skin scar inhibition by providing electrical stimulation via a multilayer stacked electret (MS‐electret), which can generate direct current (DC) electric field (EF) without any power supply equipment. In addition, the MS‐electret can easily control the intensity of EFs by simply stacking electret layers and maintain stable EF with the surface potential of 3400 V over 5 days owing to the injected charges on the electret surface. We confirmed inhibition of type 1 collagen and α‐SMA expression of human dermal fibroblasts (hDFs) by 90% and 44% in vitro, indicating that the transition of hDFs to myofibroblasts was restricted by applying stable electrical stimulation. We further revealed a 20% significant decrease in the ratio of myofibroblasts caused by the MS‐electret in vivo. These findings present that the MS‐electret is an outstanding candidate for effective skin scar inhibition with a battery‐free, physiological electrical microenvironment, and noninvasive treatment that allows it to prevent external infection.image

Research on Crosstalk Coupling of Trackside Cable in High Speed Railway

The signal and power supply of trackside equipment in Chin’s high-speed railway is usually placed in the trackside trunking to avoid the influence of external harassing signals on the cable. However, due to the different voltage levels of the cables in the trough, strong and weak current cables will produce crosstalk coupling problems, which will affect the quality of train communication and running efficiency, and even endanger the safety of train running. Therefore, it is necessary to accurately analyze the crosstalk coupling problem between the cables in the trough. In this paper, the crosstalk coupling model of trackside cable is established. The Green function method simplifies the trackside trunking model, the crosstalk coupling of the cable in the trackside trunking and the electromagnetic field distribution in the trackside trunking are analyzed by using the method of moments (MOM), and the results of theoretical calculation are verified by simulation experiments.