Power Supply Equipment Research Articles

Methodology of development and test of the electrical rocket propulsion system for telecommunication spacecraft Yamal-200 (to the 15th anniversary of operation in space)

The article summarizes the results of a 15-year operation of the Yamal-202 telecommunication spacecraft in geostationary orbit. The review of using electrical rocket engines in spacecraft in domestic and foreign projects is made. The questions of methodology for developing and testing the electrical rocket propulsion system for the Yamal-200 spacecraft are considered including features of the RSC Energia stand base, specific features of the equipment and methodology for filling tanks with working fluid such as xenon. Special attention is paid to the preliminary joint test of the power supply and control equipment with thruster modules in order to justify the long-term operation of electrical rocket engines. In the analysis of the 15-year operation of the electrical rocket propulsion system the initial operation phase of the spacecraft is shown with the cruise mode of electrical rocket thruster modules for installation at operating points 49 and 90 EL with the corresponding operating time of all thruster modules. The final data on the operating time of thruster modules KA-201 for 10.5 and KA-202 – for 15 years of operation is presented that gives significant statistics on the use of engines СПД-70. The estimate of the remaining mass of the working fluid and the capability of further operation of the electrical rocket propulsion system is made. Key words: geostationary orbit, electrical rocket engine, thruster module, united propulsion system, predelivery checkout tests, filling with working fluid.

Study on bidirectional fluid-solid coupling characteristics of reactor coolant pump under steady-state condition

The AP1000 reactor coolant pump is a vertical shielded-mixed flow pump, is the most important coolant power supply and energy exchange equipment in nuclear reactor primary circuit system, whose steady-state and transient performance affect the safety of the whole nuclear island. Moreover, safety demonstration of reactor coolant pump is the most important step to judge whether it can be practiced, among which software simulation is the first step of theoretical verification. This paper mainly introduces the fluid-solid coupling simulation method applied to reactor coolant pump, studying the feasibility of simulation results based on workbench fluid-solid coupling technology. The study found that: for the unsteady calculations of the pure liquid media, the average head of the reactor coolant pump with bidirectional fluid-solid coupling decreases to a certain extent. And the coupling result is closer to the real experimental value. The large stress and deformation of rotor under different flow conditions are mainly distributed on impeller and idler, and the stress concentration mainly occurs at the junction of front cover plate and blade outlet. Among the factors that affect the dynamic stress change of rotor, the pressure load takes a dominant position.

НЕЛИНЕЙНАЯ МОДЕЛЬ СИСТЕМЫ ЭЛЕКТРОПИТАНИЯ ПОГРУЖНЫХ ОБЪЕКТОВ С УЧЕТОМ ИЗМЕНЕНИЯ ДЛИНЫ КАБЕЛЬ-ТРОСА

Актуальность работы определяется необходимостью создания адекватных математических моделей систем электропитания сложного погружного технологического оборудования, например электроцентробежных насосов и автономных подводных аппаратов, получающих энергию переменного тока по достаточно протяженной кабельной линии. Приемлемая адекватность характеристик модели и реальной системы электропитания данного класса объектов может быть достигнута в результате учета изменяемой длины кабельной линии и различных режимов работы погружного оборудования. Использование передаточных функций в качестве промежуточных моделей основных элементов системы электропитания и операторного метода является достаточно приемлемым решением для адекватного отражения процессов изменения напряжения на нагрузке. Далее путем преобразования передаточной функции записывается нелинейная математическая модель системы электропитания в пространстве переменных состояния, которая позволяет аналитическим образом решить задачу робастной стабилизации неизмеряемого напряжения на полезной электромеханической нагрузке. Цель работы: построение нелинейной математической модели системы электропитания с передачей энергии переменного тока по кабель-тросу с учетом изменения его длины в пространстве переменных состояния. Методы: операторный метод, методы пространства состояния и математического моделирования. Результаты. Разработана методика определения параметров устройства компенсации реактивной мощности в кабель-тросе для увеличения его пропускной способности при передаче мощности на дальние расстояния при повышенной частоте. Определена аналитическая зависимость, позволяющая рассчитать индуктивность компенсирующего устройства во всем диапазоне изменения длины кабель-троса. Для построения оптимального регулятора получены полиномы, позволяющие определять коэффициенты передаточных функций при изменении длины кабеля и сопротивления нагрузки системы электропитания. На основании передаточных функций, полученных для различных режимов работы системы электропитания, определены параметры схемы замещения, позволяющей записать нелинейную математическую модель системы электропитания пониженного порядка. Проведена сравнительная оценка результатов моделирования системы электропитания с передачей энергии переменного тока по кабель-тросу, подтверждающая возможность ее описания моделью пониженного порядка в пространстве состояний. Выводы. В работе предложена методика определения параметров устройства компенсации реактивной мощности, позволяющего увеличить пропускную способность кабель-троса. На основании передаточных функций, коэффициенты которых зависят от длины кабель-троса, записана упрощенная нелинейная математическая модель системы электропитания погружного технологического оборудования. В результате полученная модель системы электропитания может быть использована для последующего синтеза оптимального регулятора напряжения в классе нелинейных систем управления.

Review and Performance Evaluation of Photovoltaic Array Fault Detection and Diagnosis Techniques

The environmentally clean nature of solar photovoltaic (PV) technology causes PV power generation to be embraced by all countries across the globe. Consequently, installation and utilization of PV power systems have seen much growth in recent years. Although PV arrays of such systems are robust, they are not immune to faults. To guarantee reliable power supply, economic returns, and safety of both humans and equipment, highly accurate fault detection, diagnosis, and interruption devices are required. In this paper, an overview of four major PV array faults and their causes are presented. Specifically, ground fault, line-line fault, arc fault, and hot spot fault have been covered. Next, conventional and advanced fault detection and diagnosis (FDD) techniques for managing these faults are reviewed. Moreover, a single evaluation metric has been proposed and utilized to evaluate the performances of the advanced FDD techniques. Finally, based on the papers reviewed, PV array fault management future trends and possible recommendations have been outlined.

A Novel, Low-Cost and Reliable Workbench for Optimal Voltage Distribution on Piezoelectric Array Actuators

The vibration control of structures is a valuable technique to increase their integrity and life-cycle. Among smart materials, the passive and active control systems based on piezoelectric elements have been studied in depth. Since the size and location of the piezo-elements on the structure are relevant matters for the damping efficiency, many works have focused on their placement optimization. Under certain circumstances, some structures may be excited by more vibration modes at the same time; hence, the signal conditioning system of the piezoelectric actuators must be capable of adjusting the driving signal in terms of voltage distribution, frequencies and associated amplitudes in order to maximize the damping efficiency. Moreover, in some applications, it could be useful to individually control each actuator therefore tailor-made power supply and signal generation systems are often necessary. This work suggests a low-cost and reliable workbench that overcomes the afore mentioned problems. The system consists of: (1) two arrays of 13 piezoceramic plates which have been glued on an aluminium beam, (2) ad hoc power supply equipment, and (3) mechanical relays arrays managed by a microcontroller for the individual handling of their operating modes. Furthermore, an Arduino board and an in-house software have been implemented in order to perform a task on each relay that is in turn wired to a single piezoelectric plate (PP). The performance of the developed system is evaluated in terms of noise and distortion of the testing signal measured at different points of the workbench. The results show that the proposed workbench may represent a good trade-off between affordability, accuracy and reliability and it can be used for several research purposes.

A Compact Proton Injector Based on the Electron Cyclotron Resonance

A proton injector based on electron cyclotron resonance is described. It can operate for a long time without the need to apply a high voltage to its power-supply equipment without providing a coolant. For a supplied microwave power of ~150 W, the extracted ion current in a continuous mode was 17 mA at an energy of 45 keV and a proton content of 68%. The proton-beam divergence was 0.4°, and the normalized rms emittance was e = 0.13π mm mrad.

Mode Selection and Resource Allocation Algorithm in Energy-Harvesting D2D Heterogeneous Network

With the rapid increase of smart mobile devices and the improvement of people's demand for wireless communication, the insufficient system capacity and shortage of spectrum resources is gradually emerging. The current wireless communication technology is facing enormous challenges. Device-to-Device (D2D) technology has become a key technology in the future 5G network, with its flexible working mode, low energy consumption, low latency and high capacity, etc. At the same time, D2D communication devices are usually powered by batteries and have a limited lifetime. The lack of spectrum resources and the single power supply for D2D User Equipment (DUE) have become an important issue for mobile communication. Energy harvesting (EH) can provide the power supply. The joint problem of mode selection and resource allocation is challenging issues in energy harvesting D2D heterogeneous networks (EH-DHNs). In this paper, mode selection and resource allocation problem with DUEs multiplexing cellular user equipments (CUEs) uplink spectrum resources for EH-DHNs is investigated. Our object is to maximize the system throughput, and the energy harvesting constraint and the quality of service of CUEs are considered. In order to tackle these issues. The mode selection and resource allocation system throughput maximization problem in EH-DHN is formulated. The formulated problem is solved by the convex optimization theory and greedy strategy. We proposed a Mode Selection and Resource Allocation algorithm (MSRA). In order to illustrate the advantage of the MSRA algorithm, we compared it with other algorithms. We also analyzed the convergence of the MSRA and the performance with different system configurations on system throughput. Comparison shows that the MSRA algorithm can improve system throughput effectively.

An External Archive‐Based Constrained State Transition Algorithm for Optimal Power Dispatch

This paper proposes an external archive‐based constrained state transition algorithm (EA‐CSTA) with a preference trade‐off strategy for solving the power dispatch optimization problem in the electrochemical process of zinc (EPZ). The optimal power dispatch problem aims to obtain the optimal current density schedule to minimize the cost of power consumption with some rigorous technology and production constraints. The current density of each production equipment in different power stages is restricted by technology and production requirements. In addition, electricity price and current density are considered comprehensively to influence the cost of power consumption. In the process of optimization, technology and production restrictions are difficult to be satisfied, which are modeled as nonconvex equality constraints in the power dispatch optimization problem. Moreover, multiple production equipment and different power supply stages increase the amount of decision variables. In order to solve this problem, an external archive‐based constrained state transition algorithm (EA‐CSTA) is proposed. The external archive strategy is adopted for maintaining the diversity of solutions to increase the probability of finding the optima of power dispatch optimization problem. Moreover, a preference trade‐off strategy is designed to improve the global search performance of EA‐CSTA, and the translation transformation in state transition algorithm is modified to improve the local search ability of EA‐CSTA. Finally, the experimental results indicate that the proposed method is more efficient compared with other approaches in previous papers for the optimal power dispatch. Furthermore, the proposed method significantly reduces the cost of power consumption, which not only guides the production process of zinc electrolysis but also alleviates the pressure of the power grid load.

Efficient, Secure, and Privacy-Preserving PMIPv6 Protocol for V2G Networks

To ensure seamless communication between mobile electric vehicles (EVs) and EV power supply equipment, support for ubiquitous and transparent mobile IP communications is essential in vehicle-to-grid (V2G) networks. However, it initiates a range of privacy-related challenges as it is possible to track connected EVs through their mobile IP addresses. Recent studies are mostly dedicated to solving authentication and privacy issues in V2G networks in general. Yet, they do not tackle the security and privacy challenges resulting from enabling mobile IP communications. To address these challenges, this paper proposes an efficient, secure, and privacy-preserving proxy mobile IPv6 (ESP-PMIPv6) protocol for the protection of mobile IP communication in V2G networks. ESP-PMIPv6 enables authorised EVs to acquire a mobile IPv6 address and access the V2G network in a secure and privacy-preserving manner. While ESP-PMIPv6 offers mutual authentication, identity anonymity, and location unlinkability for the mobile EVs, it also achieves authorised traceability of misbehaving EVs through a novel collaborative tracking scheme. Formal and informal security analyses are conducted to prove that ESP-PMIPv6 meets these security and privacy goals. In addition, via a simulated assessment, ESP-PMIPv6 is proven to achieve low authentication latency, low handover delay, and low packet loss rate in comparison with the PMIPv6 protocol.

High Electron Mobility Ge1−xSnx(x > 10%) Folding Space Charge Zone Schottky Diode for Microwave Wireless Power Transfer

The microwave wireless power transfer is a power transmission device that breaks through the limitation of the transmission line, and is helpful for handling equipment power supply problems in complex scenes. Thus, it has a wide array of applications. This paper focuses on the research and design of the core components of the receiving part of the microwave wireless power transfer, it optimizes the material physical parameters and geometrical parameters of the device to improve the energy conversion efficiency. First, we using the ADS simulation tool, the relationship between the electrical parameters of the schottky diode and the energy conversion efficiency is obtained by adjusting the SPICE parameters of the schottky diode. The optimal design principle is proposed, which lays a theoretical foundation for the optimization design of the subsequent high energy conversion efficiency rectifier device. Second, basing on the diode rectification principle and the theoretical basis obtained in the first part, a GeSn folded space charge on the insulating layer is proposed. Using the device simulation tool Silvaco to adjust the physical parameters of the device material and the geometrical parameters, the device structure of the GeSnOI folded space charge region Schottky diode is obtained. The results show that compared with the traditional structure Ge schottky diode, the folded space charge region schottky diode optimized in this paper has the advantage of significantly improving its energy conversion efficiency, and the energy conversion efficiency is improved by 8.1%.

Research on High Voltage Capacitor Voltage Drop Device

With the advent of smart grid, smart transmission lines as an important part of smart grid gradually entered the construction. In view of this, installing various testing equipment on the transmission line tower is the basic work of building intelligent transmission line. However, limited by geographical conditions or insulation conditions, there are few low-voltage power supply near the transmission line towers. It is a big problem to supply power to the low-voltage detection equipment on the towers. In this paper, a new method of capacitive buck charging for transmission line towers is proposed. A special high voltage line capacitor and voltage transformer are used in series to extract energy directly from the high voltage line. The insulator string is used as the insulation support of the overvoltage of the transmission line, and the line capacitor and voltage transformer are connected in parallel. Stable energy output is obtained to achieve reliable power supply for transmission line tower monitoring equipment. However, the power supply will inevitably suffer from lightning strikes if it is exposed to nature for a long time. Therefore, it is of great practical significance to study the transient characteristics of Lightning Overvoltage in capacitor power supply system and to study its protection technology to ensure its safe and reliable operation.

Design of Street Light Intelligent Control System Based on ZigBee and FPGA

Urban street lights are an indispensable infrastructure to ensure the safety of citizens. The energy consumed by street lighting system lighting is considerable for saving lighting energy and management costs by improving the management and control system of street lights. Street light intelligent control system, making use of modern technologies such as network communication, computer, automatic control, etc., is built based on ZigBee and FPGA. The system can realize real-time remote intelligent monitoring of the single lamp, single pole and internal power supply equipment of the street light system. On the one hand, it can realize it through monitoring of the host computer software and using a variety of control methods to optimize street lighting; on the other hand, it can realize it through the intelligent control system for its real-time data acquisition, analysis and fault warning of system operation status. The management personnel can perform some related operations by managing the street light system through the computer in the monitoring center, or logging in to the management system through the intelligent network terminal.

Optimization Method With Prediction-Based Maintenance Strategy for Traction Power Supply Equipment Based on Risk Quantification

A prediction-based maintenance (PBM) strategy can save resources while simultaneously guaranteeing the traction power supply system (TPSS) operates in a stable and reliable condition. Based on risk quantification, this paper presents a method to assess maintenance needs and optimize the PBM strategy for traction power supply equipment (TPSE). This method utilizes historical maintenance information and the fault record of the TPSE as inputs to a fault prediction model based on a Bayesian classifier. By comparing the prediction results with the actual equipment operation state, statistical parameters are obtained to calculate the reliability and economic indices for the maintenance strategies. The comprehensive maintenance risk is then quantified by integrating the dynamic inspection and fault risk costs for the TPSE. The minimum comprehensive risk is selected as the optimization objective, and the criterion for fault prediction spurs from the optimization results are used to form the PBM strategy. Practical maintenance information and fault record data of 27.5-kV vacuum circuit breakers for a TPSS are used to verify the proposed method. The results show that, by fully utilizing the current data, this method can predict equipment faults by considering multiple factors, and it can quantify the risk for a particular PBM strategy, which is also applicable to similar large-scale traction power supply facilities. To improve the PBM strategy, the approach optimizes fault prediction criteria to achieve a minimum comprehensive maintenance risk. The proposed method can provide effective data and confidence for decision makers in implementing PBM for TPSS.

Efficiency Estimation of Hybrid Electrotechnical Complex for Non-Sinusoidal Signals Level Correction in Autonomous Power Supply Systems for Oil Fields

Actuality of highest harmonics hybrid compensation in currents and voltages was gained to improve efficiency of oil fields power supply equipment. A positive effect is achieved due to implementation of active and passive filters in centralized and autonomous power supply systems with high percentage of non-linear loads. There was an observed structure of the hybrid electrotechnical complex based on a parallel active filter and two passive filters that were set for elimination of the 5th and 7th current harmonics that were generated by non-linear load represented as a power converter. This scheme was adapted for the use with a frequency-controlled electric drive due to adjustment of the parallel filter DC link and non-linear load of the frequency converter. There were developed mathematical and computer simulation models of the observed hybrid electrotechnical complex with the common DC link for the conditions of autonomous power supply at the oil field object. The control system of the autonomous electrotechnical complex hybrid part was develop. It contains phase converters and a dead space width disposal variable of relay controllers during generation of control pulses. Analyses of non-sinusoidal level adjustment efficiency of voltage and current signals were conducted after simulation of the hybrid electrotechnical complex. The calculations of technical-and-economic indices and efficiency usage were performed taking into account implementation of the hybrid electrotechnical complex into industrial power supply systems. The obtained results prove that the developed hybrid electrotechnical complex with the common DC link for the autonomous power supply of oil fields in the DG networks is efficient, reliable and can be installed in the existing power supply systems.

High purity high yield tandem B and T helper cell isolation for qRT-PCR analysis suitable for basically equipped laboratories

BackgroundMalaria is still a major health problem in sub-Saharan Africa and south-east Asia, but research on malaria in low-income countries can be a challenge due to the lack of laboratory equipment. In addition, severe malaria mainly affects very young children, which limits the amount of blood available for research purposes. Thus, there is a need for protocols that yield a maximum of information from a minimum amount of blood, which are operable in basically equipped laboratories.ResultsA protocol for tandem B and T helper (Th) cell isolation directly from whole blood, and a freezer-independent sample preservation method compatible with the warm and humid climate of malaria regions was established and validated. The protocol thereby circumvents the need of high-technology centrifuges and unimpeachable power supply for peripheral blood mononuclear cell isolation. Both purity and yield are excellent. Depending on the expression level of the genes of interest, between 2 and 5 ml of blood are adequate for reliable qRT-PCR results from both B and Th cells of healthy paediatric donors as well as paediatric malaria patients.ConclusionThis protocol for high purity high yield B cell and Th cell isolation and sample storage for subsequent qRT-PCR analysis from a minimal amount of blood is contrivable with basic equipment and independent of continuous power supply. Thus, it is likely to be of avail for many scientists performing malaria research in rural institutes or hospitals, and thus in countries where malaria is most prevalent.

Reliability assessment for traction power supply system based on Quantification of Margins and Uncertainties

The traction power supply is a crucial part of high-speed rail network. A failure of the traction power supply system may lead to delay or outage of high-speed trains that will not only have direct impact on the entire operation schedule but will also cause tremendous losses. Therefore, the reliability assessment of the traction power supply system is extremely important to ensure the transportation quality of high-speed trains and improve the economy. This paper presents a reliability evaluation method for the traction power supply system based on Quantification of Margins and Uncertainties (QMU). Firstly, the characteristics of the traction power supply equipment and system are combined to establish the observation list and then the performance channel for the equipment and system is determined. Finally, the confidence factor is calculated and the reliability of the equipment and system quantified by the quantification of the performance margin and uncertainty. In order to validate the effectiveness of the proposed method, simulations are conducted using practical operation data from a China traction power supply system. The simulation results demonstrate that the proposed reliability assessment method can account for the uncertainty and quantify the system reliability index. The proposed method has good applicability and can be used to effectively evaluate the reliability of the traction power supply system.

Rigorous assessment of existing overhead line gantries for the Elizabeth line

The Elizabeth line will use above-ground sections of existing Great Eastern and Great Western tracks between Stratford and Maidenhead where new overhead line equipment (OLE) and traction power supply will be installed. The OLE is supported by gantries of various types and configurations. In the case of the Great Eastern, the gantries date from the electrification of UK railways in the 1940s. Initial structural assessment carried out had shown that existing gantries on the route were inadequate to carry increased loading from the upgraded OLE. However, a rigorous procedure incorporating detailed non-linear structural analysis was developed that eliminated some of the inherent conservatism in traditional codified approaches. Particular benefit was found in the case of the many types of slender structure where buckling was a governing factor. Using non-linear techniques, it was possible to demonstrate that families of structures were suitable for incorporation in the Crossrail (Elizabeth line) scheme. This paper describes the approach that was used. The project is remarkable for significant programme and cost savings that were accomplished using sophisticated engineering analysis. It is also noteworthy from a sustainability point of view, as it allowed the existing infrastructure to be reused.

Determination of Energy Intensity of Autonomous Power Supplies Taking into Account Interruptible Service of Power Mains

A methodological approach for determining the energy intensity of autonomous power supplies in the presence of interruptible power service due to the overrange of supply quality indices has been considered. The modes of operation of the power supply system have been represented in the form of a Markov chain with discrete states and continuous time. The exponential rule of a working time distribution of the power feeds has been adopted. A marked graph of states of the power supply system that consists of the state electric mains, uninterruptible power supply equipment, and a standby diesel power station has been constructed. The matrix of transition probabilities has been created, and the analytical expressions have been obtained to determine ultimate probabilities. Since the ultimate probabilities are the mean relative residence time of the system in the given state, the analytical expression has been deducted to determine operating time of the storage battery used in the equipment of uninterruptible power supply. The operating time of other standby power supplies can be similarly calculated.

How Dynamic Properties of Inverters Influence Electrode Metal Transfer to the Weld Pool, and Change Structural and Phase Composition of Welded Joints Produced via High Alloyed Electrodes

Covered-electrode arc welding has been currently widely-spread in assembly and maintenance technologies, as soon as it is a reliable tool, which helps get safe permanent joints in critical structural systems applied in Arctic. It is of burning importance to further enhance accuracy in methods which assess the impact of dynamic properties of power supply equipment with various forms of energy conversion on a consumable electrode welding stability and quality. Literature review [1–11] confirms that objectives, aimed at improving critical (in terms of extreme work and low temperatures) metal structures reliability, demand innovative approaches, i.e.:

Failure Risk Interval Estimation of Traction Power Supply Equipment Considering the Impact of Multiple Factors

Quantifying the failure risk of traction power supply equipment (TPSE) is of significant importance to the safe and stable operation of the traction power supply system. This paper proposes a method for conducting failure risk interval estimation for the TPSE while accounting for the impact of multiple factors. This method consists of two parts, i.e., the estimation of failure probability interval, and the analysis and quantification of the failure consequences: 1) based on the historical statistical data of equipment failure, a credal network model of TPSE is constructed. By combining the imprecise Dirichlet model and the inference algorithm of credal network, the probability interval of equipment failure is estimated for a given operational condition and 2) the risk-based failure mode and effects analysis table is established for qualitatively analyzing the failure risk of TPSE. This, coupled with the consideration of equipment failure level, enables the quantification of failure consequences from the perspectives of both economic loss and time loss. Finally, the estimation of equipment’s failure risk interval is obtained by integrating the failure probability interval and the quantitative consequences. A case study is conducted utilizing the failure samples of contact mesh equipment derived from the practical power supply section, so as to verify the validity and usability of the proposed risk interval estimation method and the corresponding indices.