Basic Power Research Articles

Optimization of Power Prediction of BP Network with Improved Pelican Algorithm

Abstract In view of the large fluctuation of photovoltaic output power affected by different weather, accurate prediction of photovoltaic output power is particularly important for the safe and stable operation of power system. Firstly, the pelican optimization algorithm ( POA ) is improved in the following three aspects : adding Circle chaotic map to make the population evenly distributed, introducing mutation factor to expand the search range of pelican when approaching prey, adding adaptive weight and firefly disturbance to avoid falling into local optimum in the water surface flight stage ; then, in order to improve the prediction accuracy of BP algorithm, the improved pelican algorithm ( IPOA ) is used to optimize the weights and thresholds of BP neural network, and the IPOA-BP photovoltaic power prediction model is built to improve the accuracy of power prediction. Finally, this paper tests the prediction performance of IPOA-BP, POA-BP and basic BP power prediction models in sunny, cloudy and rainy days through experiments. The experimental results demonstrate that the IPOA-BP prediction model outperforms both the POA-BP and traditional BP neural network models under various weather conditions.

A novel ensemble deep reinforcement learning model for short‐term load forecasting based on Q‐learning dynamic model selection

AbstractShort‐term load forecasting is critical for power system planning and operations, and ensemble forecasting methods for electricity loads have been shown to be effective in obtaining accurate forecasts. However, the weights in ensemble prediction models are usually preset based on the overall performance after training, which prevents the model from adapting in the face of different scenarios, limiting the improvement of prediction performance. In order to improve the accurateness and validity of the ensemble prediction method further, this paper proposes an ensemble deep reinforcement learning approach using Q‐learning dynamic weight assignment to consider local behaviours caused by changes in the external environment. Firstly, the variational mode decomposition is used to reduce the non‐stationarity of the original data by decomposing the load sequence. Then, the recurrent neural network (RNN), long short‐term memory (LSTM), and gated recurrent unit (GRU) are selected as the basic power load predictors. Finally, the optimal weights are ensembled for the three sub‐predictors by the optimal weights generated using the Q‐learning algorithm, and the final results are obtained by combining their respective predictions. The results show that the forecasting capability of the proposed method outperforms all sub‐models and several baseline ensemble forecasting methods.

Studies in fractal–fractional operators with examples

By using the generalization of the gamma function (p-gamma function: Γp(.)), we introduce a generalization of the fractal–fractional calculus which is called p-fractal fractional calculus. We extend the proposed operators into the symmetric complex domain, specifically the open unit disk. Normalization for each operator is formulated. This allows us to explore the most important geometric properties. Examples are illustrated including the basic power functions.

Proposal of an Original Methodology to Evaluate the Performance of Chipper Machines

Wood fuel from the agroforestry sector is one of the main strategies cited by the EU for reducing energetic dependance on foreign markets. Its sustainability, both economic and environmental, can be improved through the optimization of harvesting and chipping operations. This study was focused on the dynamic and energetic balance of the chipping phase carried out by a chipper operated by the power-take-off (PTO) of a medium-power tractor. Both machines were equipped with sensors for real-time monitoring of fuel consumption, PTO torque and speed, trunk diameter and working time during the comminution of 61 poplar trees grown in a medium rotation coppice system. The data analysis was carried out on the entire dataset (about 29,000 records) without considering their belonging to different trees. By means of proper data ordinations, it has been possible to define all the intervals in which the chipping stopped (e.g., between two trees) and to exclude them from the intervals of actual chipping. This has allowed forcomputation of operative and actual working time, as well as of the basic power required to operate the chipper and the power for actual chipping. Subsequently, the parameter values observed during actual chipping were related to the cutting diameters measured at the same instant. Subsequently, the dataset was divided according to seven diameter classes, and, for each class, the descriptive statistical indices of working time, work productivity, CO2 emissions, energy requirement and fuel consumption were calculated. Eventually, the correlation between the variations in trunk diameter and other parameters was verified both on the whole dataset and based on the class average values. The analysis made it possible to identify the conditions of greatest efficiency for the chipper. More generally, the method could help to increase the accuracy of measurements aimed at characterizing the performance of chippers from the point of view of dynamic energy requirements as well as in relation to different wood species.

Intrasegmental recombination as an evolutionary force of Lassa fever virus.

Lassa fever (LF), caused by Lassa virus (LASV), is one of the most dangerous diseases to public health. Homologous recombination (HR) is a basic genetic power driving biological evolution. However, as a negative-stranded RNA virus, it is unknown whether HR occurs between LASVs and its influence on the outbreak of LF. In this study, after analyzing 575 S and 433 L segments of LASV collected in Africa, we found that LASV can achieve HR in both of its segments. Interestingly, although the length of S segment is less than half of the L segment, the proportion of LASVs with S recombinants is significantly higher than that with L recombinants. These results suggest that HR may be a feature of LASV, which can be set by natural selection to produce beneficial or eliminate harmful mutations for the virus, so it plays a role in LASV evolution during the outbreak of LF.

Heavy Blimp-Based Simulation Research of Integral Tower Technology

The power industry is the primary energy through the power generation equipment into electricity, and then through the transmission, transformation and distribution system to supply users as energy as the industrial sector, for the industrial and national economy and other sectors to provide basic power, is the first sector of national economic development[1]. As an important link to ensure the normal operation of the power industry, the importance of the power transmission system is self-evident[2]. The transmission tower, as the cornerstone to ensure the normal operation of the transmission system, has a large construction workload and faces problems such as complex construction environment and construction safety risks. Therefore, how to ensure the safe construction of transmission line in complex terrain is of great significance to power system construction. At present, in the construction of transmission tower, the suspension pole group tower and the whole lifting tower are the two main tower construction methods widely used. However, the pylon group tower has a great safety risk[3-4]. The State Grid has been trying to optimise the suspension of the tower. Secondly, due to the inconvenience of transportation, it is difficult for heavy lifting equipment to reach the construction site, which makes it difficult to promote the whole tower scheme using heavy lifting equipment in the mountainous terrain. In addition, the current construction of the tower group lacks scientific calculation and analysis of the force and deformation of the tower and key construction components, and there are hidden dangers such as overload and excessive deformation. Therefore, a new type of tower formation is needed to avoid the risk of personnel working at high altitudes and problems such as the inability of large heavy equipment to reach the construction site in mountainous areas[5]. In this paper, simulation technology is studied against the background of integral tower technology based on airship.

Research on Intelligent Monitoring System of Intelligent Transmission Line Based on Computer Internet of Things Technology

The author proposes an intelligent early-warning system for preventing external damage of transmission lines. The system uses TI-TMS320DM6446 as the core, the peripheral circuit configuration and video monitoring; The moving objects captured by PTZ camera are detected and identified by using mixed Gaussian model, background difference and minimum tangent matrix, and alarm signals are provided. According to the particularity of the power supply of the equipment on the transmission line, the basic power management of the system is analyzed in detail. A reliable power management scheme is designed. The practical application proves that this method has good real-time performance and has obvious effect on preventing power cable damage by force.

A Review of Polymer-Based Environment-Induced Nanogenerators: Power Generation Performance and Polymer Material Manipulations.

Natural environment hosts a considerable amount of accessible energy, comprising mechanical, thermal, and chemical potentials. Environment-induced nanogenerators are nanomaterial-based electronic chips that capture environmental energy and convert it into electricity in an environmentally friendly way. Polymers, characterized by their superior flexibility, lightweight, and ease of processing, are considered viable materials. In this paper, a thorough review and comparison of various polymer-based nanogenerators were provided, focusing on their power generation principles, key materials, power density and stability, and performance modulation methods. The latest developed nanogenerators mainly include triboelectric nanogenerators (TriboENG), piezoelectric nanogenerators (PENG), thermoelectric nanogenerators (ThermoENG), osmotic power nanogenerator (OPNG), and moist-electric generators (MENG). Potential practical applications of polymer-based nanogenerator were also summarized. The review found that polymer nanogenerators can harness a variety of energy sources, with the basic power generation mechanism centered on displacement/conduction currents induced by dipole/ion polarization, due to the non-uniform distribution of physical fields within the polymers. The performance enhancement should mainly start from strengthening the ion mobility and positive/negative ion separation in polymer materials. The development of ionic hydrogel and hydrogel matrix composites is promising for future nanogenerators and can also enable multi-energy collaborative power generation. In addition, enhancing the uneven distribution of temperature, concentration, and pressure induced by surrounding environment within polymer materials can also effectively improve output performance. Finally, the challenges faced by polymer-based nanogenerators and directions for future development were prospected.

Покращення динамічних властивостей засобу рухомості озброєння шляхом встановлення дизельних двигунів при проведенні модернізації

This article examines the possibilities of improving the dynamic properties of a weapon vehicle by installing diesel engines during modernization. It proposes a number of practical measures to achieve this goal, such as replacing a gasoline engine with a diesel engine.The article conducts a comparative analysis of the traction and dynamic characteristics of the basic gasoline power unit and the diesel power unit installed after modernization on the example of APCS 70. The necessity of modernization by replacing gasoline engines with diesel units is substantiated by means of a comparative traction and dynamic calculation and economic indicators of power units. A comparative analysis of fuel consumption is carried out and the power of the power units is compared. The disadvantages of using gasoline power units are analyzed. According to the results of the calculations, the optimal ratio of parameters that determine the dynamic properties of the vehicle of the weapon is achieved.For the calculation of the main indicators of traction and speed properties of the prototype, the numerical values of the design parameters of the APCS 70 product, which are given in the reference literature, are used.The modernization discussed in this article involves further refinement of the APCS 70's power plant compartment, which is located in the aft part of the hull. It contains two ZMZ 4905 power units assembled with clutches and gearboxes mounted on a common frame. The gasoline power units are replaced with clutch assemblies and 4-speed transmissions. Diesel power units are assembled with clutches, equipped with 5-speed gearboxes and are installed with minor modifications to the standard subframe on which the units are mounted. In turn, the replacement of the power units entails further modifications to the cooling system, fuel supply, exhaust system, engine heating system, as well as part of the electrical equipment of the power units. The transfer case and subsequent transmission of the product remain unchanged.The research provides valuable information for military equipment specialists and engineers interested in improving the performance of combat vehicles.

Numerical and Experimental Study on Preheating Burner Characteristics for Peak Shaving

With the proportion of renewable energy power in the electricity market gradually increasing, coal-fired power is transforming from primary to basic power, with it providing peak and frequency shaving. However, most current methods for peaking below 50% load have been applied industrially, sacrificing the efficiency of the unit. This is not in line with the goals of energy conservation and emission reduction. Therefore, this study proposes a new preheating-based peaking method. This study experimentally and simulatively explores the flow characteristics, pyrolysis gas law, and NOx emission characteristics of a preheating burner at 40–100% load. The results show that the burner has a significant preheating effect, producing high-temperature char and large amounts of pyrolysis gas. As the load decreases, the burner exit temperature increases, whereas the airflow stiffness decreases. There is little variation in the pyrolysis gas concentration between 40% and 100% loads. The NOx concentration at the burner outlet increases and the reduction efficiency decreases with decreasing load. At 40% load, NOx emissions are 91.53 mg/Nm3 and the reduction efficiency reaches 95.9%. Therefore, preheating is an economical, stable, and low-NOx-emission-peaking method. This study provides theoretical guidance for the application of preheating burners for the 40–100% load peaking of coal-fired units.

Analysis and Comparison Between Different Methods of Current Reference Generation for Active Filters Control.

In modern distribution systems the proliferation of non-linear loads results in a deterioration of the quality of voltage waveforms at the point of common coupling (PCC) of various consumers. Therefore, power-conditioning equipment is becoming more important for electric utilities and their customers. With the rapid development of semiconductor devices in power and control circuits, a new generation of equipment for power quality, the active power filters, has been developed. Their advantages over conventional means are more flexibility and very fast control response. The control of an active filter comprises two major parts: the reference current computation and the current control. There are two fundamental methods of generating the reference current: (i) frequency–domain methods, based on the Fourier analysis and (ii) time-domain analyze, based on the theory of instantaneous imaginary power in the three-phase circuits, often called p-q theory. The paper begins by presenting the principle of active filtering and the basic instantaneous imaginary power theory. In the hypothesis of a distorted and/or unsymmetrical load voltage system, the p-q theory has proven limitations; consequently the paper reviews and evaluates other two reference current calculation methods. Finally a comparative analyze of the three methods features is carried out.

«ГЕОПОЛИТИЧЕСКИЕ РЕВОЛЮЦИИ» КАК МЕХАНИЗМ ТРАНСФОРМАЦИИ ТЕРРИТОРИАЛЬНОЙ СТРУКТУРЫ РОССИИ XVI–XIX вв.

Based on comparing the models of territorial development of the statehood in the West and in Russia, the article identifies civilization features of the Russian state’s development, which have been determined, in essential moments, by the unique spatial-geographical and cultural-historical conditions of Eurasia. Geopolitically vulnerable position of Russia, starting from its earliest state prototype — Kievan Rus’, the openness and amorphous character of its borders facing the habitat areas of warlike steppe nomads, combined to determine the historically prolonged and complex process of stabilizing its state territory. The latter’s development not only took shape of its expansion or contraction but implied the substantial changes in the basic power configuration, as well as in the functional and strategic role of individual lands and regions. Under these conditions, one of the main directions of Russia’s state development had to become the improvement and stabilization of its geopolitical position, together with the formation of a territorial structure that would best meet these tasks. The groupings of events and processes associated with deep qualitative transformations of these areas of the state development are suggested to be defined as “geopolitical revolutions”. The content of this concept, motivations and mechanisms of the “geopolitical revolution” are analyzed using the example of the forced transformation of the territorial foundations of the Russian statehood during the 12th–16th centuries. For the Imperial era of the Russian history, it is proposed to distinguish three critically important periods of transformation which, having as the basis a similar and successively inherited “program” of actions, fall under the characteristics of the “geopolitical revolution”. This concept, making it possible to systematize historical material better and highlight the dominants of the state development, could serve as the basis for a comprehensive periodization of the Russian history.

Performance Enhancement of the Basic Solar Chimney Power Plant Integrated with an Adsorption Cooling System with Heat Recovery from the Condenser

In a previous work, a solar chimney power plant integrated with a solid sorption cooling system for power and cold cogeneration was developed. This prior work showed that reusing the heat released from the adsorption bed enhances the system’s utilization of solar energy and increases the turbine’s output power. In the present paper, a subsequent modification to the arrangement and operation of the preceding system is introduced. The primary objective of the modification is to enhance performance and increase the plant’s capacity to effectively harness the available solar radiation. The method involves placing the condenser tubes at the solar collector entrance. Therefore, the airflow captures the condenser-released heat before it enters the collector. The modified configuration and operation of the system are discussed. A dynamic mathematical model is established to simulate the hybrid system’s operation and evaluate its parameters. The obtained results show that a 5.95% increase in output power can be achieved by recovering the heat of condensation. Furthermore, the modified system attains a 6% increase in solar-to-electricity conversion efficiency compared with the basic system. The findings suggest that the modified system, which recycles condenser heat, provides noticeable enhanced performance compared with the basic system.

Ocena powojennej administracji lokalnej w latach 1944-1947 w kronikach parafialnych ks. Józefa Mroczkowskiego z Oleszyc oraz ks. Romana Penca proboszcza w Przeworsku

Assessment of the post-war administration in the years 1944–1947 in the parish chronicles of Rev. Józef Mroczkowski from Oleszyce and Rev. Roman Penc, parish priest in Przeworsk The article deals with the image of post-war administration in the eyes of the authors of the parish chronicles from Oleszyce and Przeworsk. The influence of administration on life of both authors was examined, and a comparison was made of administration in both chronicles at the same time. Its assessment in the period up to 1947 is completely different for both circuit breakers. Rev. Penc from Przeworsk was struck as a foreign element imposed on the authorities. Rev. Mroczkowski from Oleszyce, who operates in an area where the main threat of the OUN/UPA exists, has a completely different opinion about the supreme authorities. A counterweight to the Ukrainian underground are Home Army soldiers, who are expected to join the ranks of citizen militias, as well as district and municipal administrations. He is also the author of the Oleszyce family chronicle, which is responsible for its development because it includes members of the Polish anti-communist conspiracy. In comparison to the situation in Przeworsk, this power is not exerted oppressively towards the parish priest. What’s more, Rev. Mroczkowski co-created it himself, sitting on the Presidium of the District National Council in Lubaczów. The situation changed dramatically in 1947, when the administration in Oleszyce, as in the entire Lubaczów district, was taken over by communists. Since then, the threats of both chroniclers, as well as their basic power, being active.

Quantum Obfuscation of Generalized Quantum Power Functions with Coefficient.

Quantum obfuscation is one of the important primitives in quantum cryptography that can be used to enhance the security of various quantum cryptographic schemes. The research on quantum obfuscation focuses mainly on the obfuscatability of quantum functions. As a primary quantum function, the quantum power function has led to the development of quantum obfuscation because it is applicable to construct new obfuscation applications such as quantum encryption schemes. However, the previous definition of quantum power functions is constrained and cannot be beneficial to the further construction of other quantum functions. Thus, it is essential to extend the definition of the basic quantum power function in a more general manner. In this paper, we provide a formal definition of two quantum power functions called generalized quantum power functions with coefficients, each of which is characterized by a leading coefficient and an exponent that corresponds to either a quantum or classical state, indicating the generality. The first is the quantum power function with a leading coefficient, and the second is the quantum n-th power function, which are both fundamental components of quantum polynomial functions. In addition, obfuscation schemes for the functions are constructed by quantum teleportation and quantum superdense coding, and demonstrations of their obfuscatability are also provided in this paper. This work establishes the fundamental basis for constructing more quantum functions that can be utilized for quantum obfuscation, therefore contributing to the theory of quantum obfuscation.

The reform and practice of art design class Revolution in higher vocational colleges under the background of double high school

In the development of social economy and science and technology innovation, higher vocational colleges in our country in the full implementation of education department and financial department on the implementation of Chinese characteristics in planning the development of the high level of higher vocational schools and professional opinions, the continuous optimization of the art design class course system and education mode, puts forward the effective solutions for specific problems. On the basis of understanding the double-hook background, according to the implementation of vocational art and design curriculum education in recent years, this paper makes clear the practical significance of constructing smart classroom, and deeply discusses how to reform high-quality art and design classroom under the double-high background. The final experimental results prove that the reform of art design class in higher vocational colleges under the background of double high school meets the requirements of modern talent cultivation and can provide basic power for the development of art field.

Theory of Movement of the Sugar Beet Tops in Loading Mechanism, Taking into Account the Influence of the Air Flow

A new design of the haulm harvester with an improved loading mechanism has been developed, which is made in the form of a centrifugal thrower that receives the entire volume of the cut sugar beet tops, as well as an unloading pipe, the end of which is at the level of the vehicle, moving beside the haulm harvester. To substantiate the rational parameters of this loading device, a mathematical model of the movement of a particle along the thrower blade and its exit from the blade was developed in order to simulate further movement along the inner surface of the cylindrical part of the casing and its straight part before entering the vehicle. The resulting differential equation for the movement of a haulm particle along the thrower blade takes into account the influence of the airflow created by the rotation of the thrower, the blades of which capture and accelerate the air in the closed space of the cylindrical casing. The indicated differential equation includes the basic design, kinematic, and power parameters affecting the flow of the studied loading process of the tops. The solution of these differential equations on a PC made it possible to obtain graphic dependencies, with the help of which the rational parameters of the working bodies of the loading mechanism of the haulm harvester were substantiated. As calculations show, an increase in the angular velocity of rotation of the thrower and the length of its blade leads to an increase in the absolute velocity of the haulm particle M from the end of the blade. Thus, by increasing the length of the thrower blade from 0.1 m to 0.35 m and its angular velocity from 10 s−1 to 40 s−1, the absolute velocity increases from 1.2 m s−1 to 16 m s−1. At an angular speed of rotation of the thrower equal to 10 s−1, an increase in the airflow velocity from 5 to 35 m s−1 leads to a smooth linear increase in the relative velocity of particle M, as it moves along the blade of 0.67 to 0.78 m s−1. For a higher angular velocity of rotation of the thrower, equal to 20 s−1, the growth curve of the relative velocity of particle M is more intense at an airflow velocity in the range from 5 to 25 m s−1, approaching the linear law at an airflow velocity of more than 25 m s−1. In this case, the relative velocity varies from 0.9 to 1.4 m s−1.

Investigation on the triaxial creep characteristic of coarse granular materials with different initial void ratios

The creep deformation of coarse granular materials is closely related to the state of creep stress and the degree of compaction. A serious of triaxial creep tests using the single-line method were carried out to investigate the influence of initial void ratio and triaxial stress state on the creep deformation and creep strain direction of coarse granular materials. The test results primarily indicate that the creep strain increases with an increase in initial void ratio under identical stress conditions, and the volumetric creep strain decreases with an increase in stress ratio under high confining pressure conditions. Furthermore, the variation in the initial void ratio has little influence on the direction of creep strain under the same creep stress state. The effect of generalized stress on the final creep strain and creep dilation ratio were further discussed. It was observed that the final deviatoric creep strain exhibits a stronger correlation with the deviatoric stress q compared to the mean normal stress p. Additionally, the creep dilatancy decreases with an increase in stress magnitude under identical stress ratio conditions. Based on the test results, a computation model for the final deviatoric creep strain with the consideration of initial void ratio and creep stress was proposed by modifying a basic power function with deviatoric stress q as the variable. After that, a modified stress-dilatancy equation for coarse granular materials was used to predict the direction of strain during creep process. Finally, the final volumetric creep strain was indirectly calculated by integrated the computation model for the final deviatoric creep strain and the creep stress-dilatancy equation. The reasonable of the proposed model was verified through a comparison of computation results and test results.

Modernization of the instrumentation requirements to support ISO noise test standards

ISO TC43/SC1/WG28 develops the basic machinery noise test standards for products and equipment. This includes the determination of sound power levels in the ISO 3740 series and the measurement of operator/bystander sound pressure levels in the ISO 11200 series. The instrumentation requirements for these standards have historically been based on a reference the sound level meter standard, IEC 61672, supplemented by another to IEC 61260 for fractional octave filters. Both IEC standards are fundamentally based on the concept of the measurement system being a packaged sound level meter. Many modern implementations of these standards no longer use a sound level meter. Many now use multi-channel, computerized instrumentation systems and custom software. These systems provide measurement equivalence to the IEC sound level measurement standards. However, they don’t fully comply with all of the requirements in these IEC standards. Many acoustic testing programs have chosen to ignore these non-complianceissues, have implemented systems that are more efficient, lower measurement uncertainty and provide measurement equivalence to IEC 61672 and IEC 61260. As industry has already decided to implement these systems, there is a need to develop modernized instrumentation requirements to support the basic sound power and sound pressure level measurement standards using current technology.

A Multilayer Software-Defined System for High-Performance Electric Vehicle Energy Conversion

A multi-layer software-defined architecture is developed based on a type of elementary power module to improve the energy conversion performance of electric vehicle (EV) system. The proposed structure is composed of three layers: (1) application function layer for the interfaces with various types of electrified loads/sources and the corresponding control functions, such as single/three-phase grid, battery, motor, resistor; (2) elementary module layer for providing desired number of basic power module with local functions of variable frequency soft switching (VFSS) and model predictive control (MPC) to increase the efficiency with better transient performance; (3) interconnection management layer for the coordination and interconnection between the application function layer and elementary module layer to construct the complete power converter topology with desired number of elementary power module for the satisfaction of the interfaced load/source. The merits of the designed architecture include the reconfigurability to be suitable for different types of EV applications, all non-isolated topologies with common mode noise attenuation capability, improved efficiency and dynamic performance by VFSS and MPC of the elementary power module, high accuracy and robustness of the multi-layer control without being influenced by the parametric modeling error from various applications. The proposed multi-layer architecture is validated with experimental tests.