Characteristics Of Power Sources Research Articles

Robust Bi-Level Planning Method for Multi-Source Systems Integrated With Offshore Wind Farms Considering Prediction Errors

Considering the economy, reliability, and output characteristics of multiple power sources (MPS) and energy storage (ES) comprehensively, a multi-source system integrated with offshore wind farms (OWFs) and its construction cost, and operating and maintenance cost model are established. The system is mainly composed of OWFs, thermal power plants, gas turbine power plants, and pumped hydro storage plants. Given the economy of the power system and offshore wind power accommodation, a bi-level optimal capacity configuration and operation scheduling method is proposed for the multi-source system integrated with OWF clusters with the objective function of optimal total cost. Then, a robust bi-level planning method for the multi-source system integrated with OWFs considering the dual uncertainty of load and offshore wind power prediction is proposed, in which the upper and lower models are solved by an improved particle swarm optimization (PSO) algorithm and CPLEX solver, respectively. Based on the method, the cost-optimal capacity configuration and operation scheduling scheme of an MPS and ES can be obtained. Finally, an OWF group in Shandong Province is taken as an example to check the validity and feasibility of the proposed method.

Model-Based Design and Optimization of Passive Shoulder Exoskeletons

Abstract To physically assist workers in reducing musculoskeletal strain or to develop motor skills for patients with neuromuscular disabilities, recent research has focused on exoskeletons. Designing exoskeletons is challenging due to the complex human geometric structure, the human-exoskeleton wrench interaction, the kinematic constraints, and the selection of power source characteristics. This study concentrates on modeling a 3D multibody upper-limb human-exoskeleton, developing a procedure of analyzing optimal assistive torque profiles, and optimizing the passive mechanism features for desired tasks. The optimization objective is minimizing the human joint torques. Differential-algebraic equations (DAEs) of motion have been generated and solved to simulate the complex closed-loop multibody dynamics. Three different tasks have been considered, which are common in industrial environments: object manipulation, over-head work, and static pointing. The resulting assistive exoskeleton's elevation joint torque profile decreases the specific task's human shoulder torque in computer simulations. The exoskeleton is not versatile or optimal for different dynamic tasks since the passive mechanism produces a specific torque for a given elevation angle. We concluded that designing a fully passive exoskeleton for a wide range of dynamic applications is impossible.

Effect of U-Flex-to-Install and Dynamic U-Flexing on Li-Ion Battery State of Health Degradation Subjected to Varying Fold Orientations, Folding Speeds, Depths of Charge, C-Rates, and Temperatures

Abstract The demand for wearable consumer electronics, fitness accessories, and biomedical equipment has led to the growth research and development of thin flexible batteries. Wearable equipment and other asset monitoring applications require conformal installation of power sources on nonplanar surfaces. For power sources in wearable electronics, durability to sustain repetitive mechanical stresses induced by human body motion is paramount along with the usual desirable power source characteristics. Previous research documenting the reliability of statically and dynamically folded power sources is scarce and does not follow standardized test protocols. Particularly, the use of manual stressing for mechanical folding of the power sources instead of a mechanical test setup is a key shortcoming in existing literature. Data are lacking on battery life cycling and in situ mechanical stress-testing of the power sources including their impact of performance and reliability. This study aims to overcome these deficiencies by testing a commercial Li-ion power source under static as well as dynamic folding. Furthermore, the fold orientation and its fold speed are varied to evaluate the effect of different mechanical stress topologies on the power source. Finally, a regression model was developed to capture the effect of these use parameters on battery capacity degradation.

Algorithm for Optimizing the Parameters of the Combined Power Supply System for Electrical Unmanned Aerial Vehicles

In addition to the existing algorithms, an algorithm has been developed to optimize the parameters of a combined power supply system for unmanned aerial vehicles (UAVs) with an electric motor, which allows taking into account specific conditions and modes of use of UAVs. The characteristics of chemical power sources are given, which should be taken into account when choosing the most preferred type of chemical power source. A scheme for distributing energy consumption in the UAV power supply system has been developed and the features of its functioning have been noted.

Імпульсні перетворювачі зі зниженою пульсацією вихідного струму

When developing pulse converters, in order to ensure a low level of output current ripples, one should seek a compromise between the overall size of the elements and acceptable losses in them, while taking into account the dynamic characteristics of power sources as closed systems with feedback. Using multiphase pulse converters can help solve the said problem, but will not ensure a low level of output current ripples in a wide range of the duty cycle of the control pulses. This study aims to find a pulse converter topology capable of ensuring the reduction of the output current ripples, while maintaining the power and volume of the structure. The paper demonstrates the relevance of the study of pulse converters aimed at obtaining a low-ripple output current for powering sensitive loads and gives an overview of ways to reduce the ripples and the most common topologies of converters. The authors describe the results of the practical application of the developed experimental stand and analyze the obtained dependences of the output current ripples on the volumes of the power sections of the converters of different topologies under the same power and frequency. Recommendations are given for choosing the type of converter in each specific case in terms of reducing ripples.

Parametric study on AC square waveform welding

The quality and productivity of submerged arc welding (SAW) products are significantly influenced by the power source characteristics (i.e., direct current or alternating current power source). One of the latest developments in the SAW power sources is alternating current (AC) square. The square waveform provides fast polarity reversal from positive to a negative peak which resolves the problem of arc extinguish that occurs during polarity cross-over in sine or triangular waveform. This paper presents the parametric study of AC square waveform arc SAW of heat resistant steel. The effects of change in process variables, namely frequency, electrode negative (EN) ratio, current, and welding speed, on the process outcomes such as bead width, penetration depth, deposition rate, and flux consumption rate are observed through experimentation. All the outcomes follow a non-linear trend except deposition rate, which follows almost a linear trend with the variation in welding current. The bead width, penetration depth, and deposition rate increased with the increase of current, whereas the bead width decreased with the rise of EN ratio and welding speed. The deposition rate follows an increasing trend with an increased EN ratio and a decreasing trend with welding speed. A similar observation is noticed in the case of penetration depth which increases with the increase of welding speed and decreases with the increases of EN ratio. Concerning each parameter studied, the flux consumption rate shows a parabolic variation, i.e., first increases and then falls. The frequency does not have much impact on the process outcomes. A comparison of AC welds with those obtained with direct current is presented concerning the attributes mentioned above. The parametric study results in this investigation are corroborated with the physics of the process to make them more useful for industrial application. The key finding of this investigation is that the AC square arc welding can maintain penetration at a higher welding speed, which significantly improves the productivity.

An ameliorative whale optimization algorithm (AWOA) for HES energy management strategy optimization

To reduce energy consumption and emissions as well as maximize the energy utilization rate in a hybrid electric ship (HES), this study has proposed an ameliorative whale optimization algorithm (AWOA) to optimize the fuzzy rules for ship’s hybrid power system which consists of a fuel cell, an accumulator battery and a super-capacitor. In this paper, firstly, the hybrid power system model of the ship has been established based on the characteristics of various power sources. Next, combining with difference algorithm, an AWOA is introduced to tackle the problem of being easily trapped into a local optimum when using whale optimization algorithm (WOA) alone. The effectiveness of the enhanced optimization method is validated by using ten different test functions. Finally, a simulation is performed to verify the effectiveness of the proposed method using the MATLAB platform. Comparing to other energy management strategies, the proposed AMOA strategy can minimize energy consumption, enhance the energy efficiency, and maintain favorable economic benefits in the meantime.

Bioinspired Triboelectric Soft Robot Driven by Mechanical Energy

AbstractA sustainable power source is a key technical challenge for practical applications of electrically responsive soft robots, especially the required voltage is over several thousand volts. Here, a practicable new technology, triboelectric soft robot (TESR) system with the primary characteristics of power source from mechanical energy, is developed. At its heart is TESR with bioinspired architectures made of soft‐deformable body and two triboelectric adhesion feet, which is driven and accurately controlled through triboelectric effect, while reaching maximum crawling speeds of 14.9 mm s−1 on the acrylic surface. The characteristics of the TESR, including displacement and force, are tested and simulated under the power of a rotary freestanding triboelectric nanogenerator (RF‐TENG). Crawling of TESR is successfully realized on different materials surfaces and different angle slopes under the driven of RF‐TENG. Furthermore, a real‐time visual monitoring platform, in which TESR carries a micro camera to transmit images in a long narrow tunnel, is also achieved successfully, indicating that it can be used for fast diagnosis in an area inaccessible to human beings in the future. This study offers a new insight into the sustainable power source technologies suitable for electrically responsive soft robots and contributes to expanding the applicability of TENGs.

A study on optimizing the characteristics of lithium-ion battery power source and operating cost for hybrid motorcycle

This study presents a research related to a Plug-in Hybrid Electric Motorcycle (HEM) which renovated from a Honda Lead 110cc with rear wheel is driven by original internal combustion engine and continuously variable transmission, while front wheel is directly-driven by a 48V – 1,000W BLDC Hub-Motor. The research focuses on optimal calculating, designing, prototyping and testing an electric power supply using Lithium-ion (Li-ion) battery pack to replace the lead–acid battery. The simulation and experimental results are able to evaluate the dynamic characteristics and operating cost of HEM. The study has been designed and prototyed a 48V – 33Ah Li-ion battery pack with a Battery Management System (BMS) circuit embeded on the vehicle. The battery pack is 10.84 (kg) weight and 8.11 (l) volume, reduced 30 (kg) and 12.89 liters compared to the lead-acid battery where battery life is greater than 2,000 cycles. In only electric motor mode, the longest distance of the HEM is 78.77 (km) for a half load, only driver, and 65.83 (km) for full load, one driver, and one passenger. Maximum speed is 52.67 (km/h) for a half load and 48.42 (km/h) for full load. In hybrid mode until SOC reduce to 50%, HEM can travel 64.366 (km) for a half load and 54.477 (km) for full load. The fuel consumption in the each case is 2.162 and 2.425 (l/100km), 0.5 liter lower than the original one and 0.3 liter lower than lead-acid battery. The cost of investment in HEM is 56 million VND and the operating cost is 1,106 VND/km, while the original vehicles are 40 million VND and 1,352 (VND/km). For every 1km using hybrid vehicles, 246.88 VND will be saved, after about 3.1 years, it will recoup the spending on investment. At the end of the motorcycle life cycle is about 200,000 km, and 43 million VND will be saved.

Energy Management Strategies for Hybrid Power Systems Considering Dynamic Characteristics of Power Sources

Due to the rising concern of environmental problems, fuel cell hybrid power systems have been proposed to be an ideal substitution to diesel engines. However, the hybrid power system has brought many challenges, one of which is the power splitting among different power generation technologies. In this paper, a wavelet transform and fuzzy logic based energy management strategy is proposed for a fuel cell/battery/ultra-capacitor hybrid power cruiser considering their dynamic characteristics. The energy demand of the cruiser is decoupled into different frequencies by wavelet transform and distributed to different energy sources according to their dynamic characteristics. To ensure long-term reliable operation of the hybrid power system, fuzzy logic is proposed to keep the state of charges of the battery and ultra-capacitor within safe range. The proposed energy management strategy is applied to a hybrid power cruiser in MATLAB/Simulink and two cases are studied considering different initial states of charge of the energy storage system. The results show that the proposed energy management strategy enables the fuel cell to supply about 50% of the high frequency power and reduce the peak power supplied by the fuel cell by 80% - 100% when the initial state of charge of the ultra-capacitor is low, and the fuel cell supplies around 400% higher than the low peak power and 20% of the high peak power when the initial state of charge of the battery is low.

A Three-Dimensional Complex Measurement Model-Based Avionic Radio-Frequency Power Source Health Assessment Method

Health assessment is an important part of PHM technology, which is crucial to product state monitoring and management. With the complexity of product structure and diversification of functions, the product health presents uncertainty under the complex influence of multiple factors. Nowadays, the general health assessment method is relatively simple and only considers the product function completeness, and the assessment effect accuracy still needs to be strengthened in the actual working environment. Most assessment parameters and assessment methods are selected ignoring the impact of environmental changes and operating time performance. Therefore, a new health measurement method for the avionic radio-frequency power source based on a three-dimensional complex measurement model is proposed. Firstly, the product health definition is proposed, and the health connotation is analyzed from three-dimensional aspects containing functional integrity, environmental adaptability, and temporal sustainability. According to the function and structure characteristics of radio-frequency power source, the health characterization parameters are then obtained and the health assessment parameter system is established. Finally, the three-dimensional complex measurement model is given, and the RF power source health assessment is carried out comprehensively from integrity, stability, and reliability aspects. The three-dimensional health assessment method provides a new way to solve the uncertainty of product health state under multiple factor effects, which is conducive to the targeted optimization management strategy.

Data-driven robust day-ahead unit commitment model for hydro/thermal/wind/photovoltaic/nuclear power systems

According to the complementary characteristics of various power sources, this paper establishes a data-driven robust day-ahead unit commitment model for a hydro-thermal-wind-photovoltaic-nuclear power system that can be used by the independent system operaters (ISOs). A data-driven robust optimization method based on the robust kernel density estimation (RKDE) is employed to deal with the uncertainties of wind and photovoltaic (PV) power. That is, the distributional information of wind and PV power is extracted by RKDE from the big data, then it is incorporated into the data-driven uncertainty set, and finally a robust optimization model is formed. In view of the facts that the conventional water spillage methods fail to pay equal attention to the benefits of the basin and the individual hydro plants, eight kinds of strategies that can make the water spillages or hydropower curtailments distributed proportionally in each hydro plant are proposed. In addition, the operating model of nuclear power unit involved in peak load regulation is established to promote its operational flexibility. The numerical results and simulation on a modified New England 39-bus system verify the superiority and practicability of the proposed model.

Complex mathematical modelling of mechatronic modules of promising mobile objects

The characteristics of power sources affect the performance of autonomous electrically driven systems, such as unmanned aerial vehicles, aircraft missiles, guided bombs, torpedoes, space and aerospace vehicles, controlled gliding parachutes. The creation of control systems for the aircraft flight control surfaces of autonomous mobile objects is an urgent topic in modern research. This article provides how a mathematical model based on integrated approach is developed for an energy-efficient mechatronic module for control systems of promising mobile objects powered by various current sources; a comparison of the energy and dynamic characteristics of mechatronic modules of promising mobile objects for various power options is made. As a result, a new type of integrated power-supply source based on capacitive energy storage with floating charge from a primary chemical source of current has been developed. The proposed approaches, dependencies and algorithms can be used in the design of highly efficient mechatronic control algorithms for autonomous mobile objects of a new generation.

Optimal two-stage dispatch method of household PV-BESS integrated generation system under time-of-use electricity price

The Photovoltaic (PV) and Battery Energy Storage Systems (BESS) integrated generation system is favored by users, because of the policy support of PV power generation and improvement of the grid-connected electricity price mechanism. And the operating efficiency and economy of the PV-BESS integrated generation system are closely related to the day-ahead dispatch strategy. Therefore, to improve the operating efficiency of the system and user benefit, this paper proposes an optimal two-stage dispatch strategy of household PV-BESS integrated generation system under the market environment of time-of-use (TOU) price strategy and a dynamic adjust strategy to cope with the forecast error. The first stage is the battery charging stage in the TOU price valley time, and the second stage is the PV output power dispatching and battery charge–discharge power scheduling stage in the non-valley time. The strategy combines energy storage strategy with a PV optimal dispatching strategy, to make full use of the double-sided characteristics of power source and load of the battery, thus achieving peak shaving and valley filling and reducing the load difference between peak and valley of the grid. The impact of sunrise time on energy storage strategy is also considered in this study. Then, the models of the two-stage dispatch strategy and the household PV-BESS integrated generation system are established under TOU price. When the PV output power is greater than the load demand, part of the surplus power will be sold to the grid and the other part will be stored in the battery. The ratio of the selling part is defined as the grid-connected ratio, and it is taken as the decision variable, and some factors are taken as the constraint condition, such as battery charge–discharge power, power balance, etc. The objective function is the optimal user benefit, and it is solved by the particle swarm optimization (PSO). When the forecast error happens, the power exchange of battery and the electricity sent to the grid will be adjusted, and the subsequent planning needs to be re-optimized to maintain the optimal dispatch result. Finally, the rationality and effectiveness of the models and strategies are verified by taking the dispatch of the household PV-BESS integrated generation system during a dispatch day under three typical scenarios as an example, and a sensitivity analysis is carried out.

A Lockable Abnormal Electromagnetic Signal Joint Detection Algorithm

With the development of computers and network technologies, network security has gradually become a global problem. Network security defenses need to be carried out not only on the Internet, but also on other communication media, such as electromagnetic signals. Existing electromagnetic signal communication is easily intercepted or infiltrated. In order to effectively detect the abnormal electromagnetic signal to find out the specific location, then classify it, it is necessary to study the way of communication. The existing electromagnetic signal detection accuracy is low and cannot be located. Considering the characteristics of different power sources in different locations, combined with spark streaming technology and machine learning classification technology, a joint platform for electromagnetic signal anomaly detection based on big data analysis is proposed. The electromagnetic signal is abnormally detected by feature comparison and small signal analysis, and the position and number between the signal sources are determined by three-point positioning and signal attenuation. The experimental results show that the method can detect abnormal electromagnetic signals and classify abnormal electromagnetic signals well, the accuracy rate can reach 95%, and the positioning accuracy can reach 89%.

MATHEMATICAL MODEL OF ENERGY EFFICIENCY OF MECHATRONIC MODULES AND POWER SOURCES FOR PROSPECTIVE MOBILE OBJECTS

Intensive development of equipment contributes to a significant impact on the high level of competitiveness of new samples, improving technologies, and promise of enshrined ideas as well as resource intensity and time of their implementation. The relevance of the scientific paper lies in the fact that in the process of designing drive systems for guiding aviation equipment, one of the important elements is taking into account the limitations on the power source energy storage. The purpose of the scientific paper is to develop a mathematical model of energy efficiency of mechatronic modules and power sources for prospective mobile objects. An integrated approach is used to study the influence of structures and elements of storage devices on the characteristics of power sources in the interest of finding the ways to increase the energy efficiency of the entire drive system for guiding mechatronic modules of aviation systems in general. It has been determined that in order to reduce the weight-size parameters of the power supply source, the stabilizer in the power section, as a rule, is not set. It has been found out that power and information sections of drive systems differ from each other in terms of the stability of the energy coordinates. And stabilized parameters (potential, current) are necessary only for the information channel. With the help of analytical dependencies, the main parameters of the primary source were evaluated depending on the efficiency of the consumer, efficiency of the stabilizer and efficiency of the secondary power source. A method to study the influence of elements of the energy (power) channel on the output power of the power source the mechatronic modules for prospective aviation mobile objects (autonomous aviation drives, guided missiles, guided parachute systems) is being developed.

Study of pulsed arc processes at periodic switching of volt-ampere characteristics of arc power source

Study of pulsed arc processes at periodic switching of volt-ampere characteristics of arc power source

Исследование импульсно-дуговых процессов при периодическом изменении вольт-амперных характеристик источника питания дуги

Исследование импульсно-дуговых процессов при периодическом изменении вольт-амперных характеристик источника питания дуги

Research on Optimal Operation Strategy of Multi-energy Power System Considering Complementary Coordination

Abstract Due to the obvious different characteristics of multi-energy power sources, it is necessary to take into account the economic and safety requirements of the power grid at the same time to achieve optimal operation strategy (OOS). This paper focuses on the OOS of multi-energy power system (MEPS), which contains wind power, cascade hydropower, thermal power, and pumped-storage power. Considering the complementary coordinationc characteristics of different types of energy, a completed set of day-ahead coordinated and optimized operating models of MEPS is established, with multiple optimization objectives of maximizing the safety, economy and renewable energy consumption. In order to solve this complex multi-objective problem, a three-stage solution method based on Benders decomposition is proposed. Through decoupling the safety object and economic object of MEPS, efficient solution of the OOS is achieved. The digital simulation discusses the influence of factors such as the diversity of natural scenarios and the safety requirements of the system operation, and simulation results verify the effectiveness of proposed strategy.

Study of Local Consumption Measures to Yunnan Small Hydropower

Focus on the phenomenon of increasing surplus electricity of small and Medium-sized Hydropower stations in Yunnan Province, After introducing the distribution, capacity, quantity, Production and operation status of YunNan small hydropower and so on. This paper Researched and Analysed the power market、structure of load and energy consumption characteristics to YunNan power system. According to the realities of power source characteristics、structure of load and power market of YunNan power system, the methods that “combination of tobacco with hydropower”、developing electricity consumption for rural residents、market transaction and energy substitution are proposed to promote the local absorption of YunNan small and medium sized hydropower. According to the existing industrial policies and industry data of Yunnan, these measures can effectively promote the local absorption of small hydropower in Yunnan.