Economic Operation Mode Research Articles

Optimum management of microgrid generation containing distributed generation sources and energy storage devices by considering uncertainties

In recent years, the financial and energy crises have made the economical and safe operation of distribution microgrids one of the main challenges for operators. In this regard, the optimal distribution of the microgrid, considering the favorable indicators of Generation and consumption, significantly improves the quality of the development and economic operation of electricity grids. On the other hand, distribution microgrids have many problems and complications due to the presence of DG sources and the uncertainties caused by them in Generation and consumption, such as the inability to solve optimal load distribution using common and common calculation methods. Therefore, grid technical indicators such as voltage deviation and losses in solving load distribution add to the complexity of related issues. To solve the challenges raised in the distribution microgrid, this paper proposes an optimal load distribution model that models the uncertainties in the distribution microgrids using the Monte Carlo method. Using meta-heuristic algorithms, the optimal Generation function by modeling grid security constraints such as voltage deviation, losses, and a load limit of the system should be in economic operation mode, and then the power distribution equations should be solved. The battery can supply 1 kW of active power to the system at a cost of 1 unit/kW during the high cost period if it absorbs 1 kW of active power at a cost of 0.92 units/kW during the low cost period. Additionally, the active and reactive power losses have been decreased to 0.3kW and 0.2kW, respectively, by utilizing the suggested methodology. The simulation results show that the proposed method performs satisfactorily and that the modeling is simulated in MATLAB software.

Research on the spatial effect of digital economy development on urban carbon reduction

Cities are one of the main sources of regional carbon emissions, and reducing urban carbon emission is the key to reducing emissions. The digital economy has transformed the economic operation mode, and it is a significant approach to support the “dual carbon goals” (carbon peaking and carbon neutrality). This article considers the externalities of the digital economy and carbon emissions. And we use spatial econometric models to analyze the effectiveness of digital economy in empowering carbon emissions reduction. Besides, we explore the static and dynamic spillover effects, and use spatial Durbin panel quantile model to analyze the digital economy’s heterogeneity on carbon emissions. Research has shown that the digital economy has a remarkable carbon reduction effect, and the conclusion remains valid after considering robustness tests such as replacing the weight matrices, calculation methods, and proxy variables. The analysis of static and dynamic spillover effects indicates that the degree of the digital economy’s impact on carbon emissions are significantly different. Heterogeneity analysis shows that as the digital economy develops from a low level to a high level, its impact on carbon emissions also shifts from positive promotion to negative suppression. This paper proposes a policy reference to help the development of digital economy and promote carbon neutrality in the face of severe environmental challenges.

Research on optimal power flow of AC/DC hybrid system for civil more electric aircraft

Modern civil more electric aircraft often use AC/DC systems instead of AC systems to reduce the weight of the power system. Compared with the AC/DC system of the land power grid, the aircraft power system needs to pursue economic operation mode under more complex security constraints. This paper establishes the optimal power flow model of the AC/DC hybrid system of more electric aircraft, which takes minimizing the active power loss of the line as the optimization objective, including the steady-state operation constraints and security constraints of the AC/DC system. The interior point method and prediction correction interior point method are used to solve the model. Then, based on the simplified steady-state model of the B787 power system, the model and algorithm are verified by experiments. The experimental results show that by optimizing the power flow distribution of the power system, the power utilization efficiency of the system has been significantly improved, and its stability and reliability can also be better guaranteed.

OPTIMIZATION OF COMPRESSOR STATION LOADING AT VARIABLE COSTS OF TRANSPORTED GAS

During the operation of the gas pipeline system of the Russian Federation, a significant share of natural gas is consumed for the own needs of compressor stations of main gas pipelines.According to Gazprom's reporting, the share of natural gas for technological and fuel needs reaches 7 % of the production volume. The inefficient use of natural gas can be reduced by energy saving measures implementation.Energy saving issues are important not only for Gazprom PJSC, but also for the country's economy as a whole. The highest priority of the «Energy Strategy of Russia for the Period up to 2035» and «The Concept of Energy Saving and Energy Efficiency Improvement of Gazprom PJSC» is the maximal realization of all available energy saving potential.Saving of energy resources can be achieved by organization of their efficient con-sumption, the use of innovative energy-saving technologies and equipment, reduction of losses and gas consumption for the own needs of compressor stations.The article presents the results of the analysis of the parameters of natural gas pumping through the Chelyabinsk – Petrovsk main gas pipeline on the 112–292 km section operated by Gazprom Transgaz Ufa LLC.It has been established that the monthly unevenness of the gas supply through the gas pipeline under consideration varies from 0.062 to 0.195. As a result, in many modes, the compressor station, regardless of any possible schemes for switching on gas pumping units, does not allow the planned gas pumping mode to be ensured without bypassing part of the gas through the recirculation circuit of the station.One of the solutions to this problem is the installation of a recirculating valve, which allows to provide the required volume of gas flow through the recirculation line, while providing an economical mode of operation of the compressor station.

The Rise of Invisible Economy and its Philosophical Reflection

Since the new century, the progress of science and technology and the rational transformation of its achievements have brought about the rapid rise of intangible economy. The knowledge-based, image-based, programmatic, and branded nature of capital, as well as the spillover, sharing, and unstable ownership of products, are its prominent features. The rise of intangible economy has overturned the traditional economic operation mode in various fields such as economic structure, industrial pattern, organizational mode, and labor form, and has also triggered philosophical thinking about this new economic paradigm: data elements have become the first production factor with ontological significance, and the elasticity of labor mode has brought about the spiritual illusion of free and autonomous labor, and social polarization is rapidly intensifying.

Preparation of wells using an electrohydraulic drill and modeling of heat transfer processes in heat transfer elements of a heat pump

The article discusses the use of innovative electrohydraulic technology in the preparation of vertical ground heat exchangers to create heat supply using heat pumps. The discharge energy in the operating range varied E=900÷2600 J. The most economical mode of operation of the electrohydraulic installation is carried out with the following parameters: discharge voltage 30÷51 kV, capacitor bank capacity 2 µF and interelectrode distance 8÷15 mm. It is determined that the optimal energy of destruction of natural materials depends on their thickness. Based on the research, the limits of the electrophysical parameters of the approach were established, at which the concentrated destruction of hard rocks – the main stones ‒ begins. The effective amount of energy for the destruction of stones with a thickness of 53 mm is 900 J. For stones with a thickness of 78 mm, there should be 2600 J. If to increase the energy of the discharges to 1837 J, the process of complete destruction of the stones is underway. Using an electro hydraulic drill, we have prepared vertical wells up to 25 m deep. In the future, we have installed special temperature sensors along the length of the pipes, inside the well. Using a software product (Temp Keeper), data from temperature sensors are received in real time. This program allows to visually monitor temperature changes occurring at a local point. Temperature and time dependences are also obtained at coolant velocities of 0.2÷0.4 m/s. A significant decrease in the temperature in the well and at the outlet was observed at a coolant velocity of 0.35 m/s for one hour. The study conducted on the basis of the data obtained enables to achieve higher optimal drilling performance compared to conventional installations

The Impact of Digital Economy on Circulation Efficiency: Empirical Evidence from China's Postal Industry

With the rapid development of digital technology, the traditional economic operation mode has been completely changed. Digital economy has become a new driving force for world economic growth. In the context of the new development model, accelerating the development of digital economy, deepening circulation reform and improving circulation efficiency have important theoretical and practical significance for stabilizing the national economic cycle. In order to explore the influence of the development of digital economy on the efficiency of circulation industry, this paper firstly expounds the basis of dividing the circulation industry from the theoretical level based on Marx's circular economy theory, and puts forward the mechanism of the influence of digital economy on the circulation efficiency. The DEA-Malmquist model is used to calculate the productivity of the total factors of the postal industry to represent the circulation efficiency. The regression results show that the development of digital economy has significantly improved the circulation efficiency of China's postal industry.

An Extensive Study Using the Beetle Swarm Method to Optimize Single and Multiple Objectives of Various Optimal Power Flow Problems

An electric energy generation system, under the economic operation mode, is an imperative mission in the power system function. This article deals with the use of beetle swarm optimization algorithm (BSOA), for optimal power flow (OPF) solution, in an effective approach. BSOA is a competent optimization technique, to handle multimodal, nonlinear, and nondifferentiable objective functions. The proposed OPF is modeled by numerous objective functions, formulations with constraints, examined with thirty-one different cases, on the three distinguished test systems (IEEE 30, 57, and 118-bus), using single and weighted sum multiobjectives. Six new multiobjective cases are also studied. The control variables, such as real generation of power, tap setting ratio of transformers, bus voltages magnitudes, and the values of shunt capacitor, are also optimized. Potency and robustness of this proposed method were investigated and evaluated with more recent findings reported in the literature. This extensive study revealed the preeminence of the presented technique, applied to OPF problem, with intricate and nonsmooth objective functions.

Model Predictive Control Based Coordinated Voltage Control for Offshore Radial DC-connected Wind Farms

In this study, a coordinated voltage control strategy based on model predictive control (MPC) is proposed for offshore radial DC-connected wind farms. Two control modes are designed in this strategy. In the economic operation mode, the wind farm controller generates optimal active power references as well as bus voltage references of medium-voltage collector for DC-connected wind turbine (DCWT) systems and high-voltage DC/DC converters, where the goal is to minimize power losses inside the wind farm and ensure that voltages are within a feasible range, all while tracking the power references. In the voltage control mode, the main control objective for the wind farm controller is to minimize voltage deviations from the rated voltage. With the MPC, the control objective and operation constraints can be explicitly represented in the optimization problem while considering the dynamic response of the DCWT system. In addition, a sensitivity coefficient calculation method for radial DC-connected wind farms is developed to improve computational efficiency. Finally, DC-connected wind farms with 20 wind turbines are used to demonstrate the performance of the proposed strategy.

Research on optimization strategy of transformer economic operation mode considering digital twin technology

Considering the overall environment of the power field, power transformer is one of the most important energy consuming devices in the substation, and the digital analysis technology of power transformer carbon footprint has become one of the hot issues. Taking a certain brand power transformer as an example, the no-load loss, load loss and stray loss of power transformer under different load conditions are calculated and analyzed by using electromagnetic finite element numerical analysis method, and then the digital twin model of power transformer is built. Combined with the digital twin model of power transformer, the carbon footprint of transformer is analyzed. Finally, the economic load coefficient of transformer is determined, and the optimal economic operation mode of substation is established. This method can provide a scientific basis for the construction of digital, low-carbon and energy-saving substations, while meeting the optimal efficiency and the fastest solution.

STUDY OF THE INFLUENCE OF CHANGING THE PARAMETERS OF BRUSHLESS MAGNETOELECTRIC MOTORS OF THE RETURN-ROTARY MOTION ON THEIR CHARACTERISTICS

The paper presents the results of studies on the influence of changing the parameters of a specialized brushless magne-toelectric motor on its characteristics in the mode of return-rotary motion. The frequency dependencies of the amplitude of the rotor oscillation angle, the effective value of the stator current, the efficiency index of the motor operation mode, the amplitude of the angular speed of the rotor oscillations, the amplitude of the stator voltage, the total value of losses in the motor are given. The dependences of the resonant frequency of mechanical oscillations on the changing values of the elasticity coefficient, the moment of inertia, and temperature-dependent parameters are determined. The depend-ence of the maximum value of the efficiency of the return-rotary motion motor on the viscosity coefficient of the me-chanical load is obtained. It is shown that the most economical mode of operation of the motor is provided under the condition of resonance of mechanical oscillations. Ref. 11, fig. 5.

Multi-object optimal configuration of energy storage-photovoltaic capacity in AC/DC active distribution network

Abstract The AC/DC active distribution network is considered as an efficient way to achieve intelligent use of electricity. However, the economical configuration of distributed generation is critical for system economic operation. In the power distribution network, the economic operation mode of the photovoltaic power generation, storage battery and load are established firstly. Considering the cost of equipment installation, replacement, operation and maintenance, power purchase cost, and power sales profit, the use life of battery and security constraint, a multi-object economics evaluation function is then established. By optimizing the install capacity of distributed power generation, the operating economy of the distribution network is significantly improved. Finally, using the operating data of the partner-type intelligent power generation system in Lianyungang, the total cost of the operating state is calculated to determine the optimal capacity allocation scheme of the system, and the effectiveness of the proposed capacity allocation method is verified.

Development of China's Internet of Things Industry from the Perspective of Industrial Economics

Industrial economics is generated on the basis of the in-depth development of the industry. It is generated under the wide application of Internet technology, mainly to optimize the economic operation mode between industrial structure, development and construction. Under this background, the Internet of Things industry is also developing gradually.

Research of Economic Operation and Control Strategy for PV-Storage-Charging Integrated Power Station

This paper proposes an economic operation mode and control strategy for an PV-storage-charging integrated power station. By optimizing the capacity configuration and analyzing the mechanism relationship of its various operating modes, this paper establishes the system model including PV system power, energy storage SOC and charging spot power, and gives its economic operation constraints. Based on statistical analysis of historical data, the strategy optimizes the operation mode dynamically to control the grid power flow and balance the system power supply and load. Simulation results verify the economic and stable operation of this strategy.

Study on Integrated Energy System Scheduling Optimization Based on Runoff Algorithm

With the advancement of economic globalization, set energy production, supply and use of integrated energy system has become the current social indispensable material base, its advantage is to utilize the energy such as natural gas, wind energy, solar energy is transformed into each other basic conditions, based on the use of renewable function between the electric energy development model, in order to reduce harmful emissions and effectively promote the consumption of energy storage, supply and its efficiency for the development goals, finally realizes the comprehensive optimization of energy system operation and development. However, the practice based on integrated energy scheduling can not achieve the best expected results, and there is a paradox between the theoretical basis and the fact. Therefore, based on the study of integrated energy system scheduling optimization, combined with different research status at home and abroad, this paper proposes a runoff algorithm to realize the economic operation mode of energy system, in order to solve the problems in the implementation process of integrated energy system scheduling, and promote the development trend of high efficiency and stability.

Evaluation of natural gas saving measures in public educational institutions

The article analyzes the data of gas consumption for the heating periods and confirms that for the actual outdoor air temperatures there is a decrease in gas consumption. Necessary heat loads and gas consumption were determined to ensure the required indoor air temperature in the premises of the educational buildings with the proposed mode of gas savings by lowering the indoor air temperature, the so-called economical mode of operation of the boiler room. The theoretical economy of gas from lowering the temperature regime is determined. To increase the accuracy of the experiment, the comparison of the amount of gas consumed was performed in terms of working and non-working periods of the day. Based on these studies, it should be noted that the actual plot can be used to determine the actual gas savings in real conditions.

Дослідження експлуатаційного режиму свердловин водозабору та водогону

Наведено результати гідравлічних досліджень експлуатаційних режимів роботи водогону на ділянці від водозабору до підвищувальної насосної станції. Визначено та обґрунтовано режим експлуатації водогону на підставі гідравлічних досліджень і експлуатаційних показників роботи свердловин. Через наявність рельєфного водорозділу траса водогону за довжиною знижується від водозабору на 52 м до підвищувальної насосної станції. З'ясовано експлуатаційний режим роботи насосів свердловин включно з фактичним їх напором. Встановлено, що експлуатаційний напір насосів свердловин, який становить 30 м, є надлишковим для цих умов. Отож, доцільно замінити та модернізувати насоси свердловин на насоси з нижчим напором, та вищим коефіцієнтом корисної дії. З'ясовано наявність безнапірної і напірної течії води у водогоні залежно від величини подачі води. Встановлено, що безнапірна течія характерна для витрат води, близьких до середньогодинних у діапазоні 3000-4000 м3/год. За більших витрат води у водогоні наявний напірний режим течії. Визначено необхідний напір насосів свердловин з урахуванням режиму роботи водогону. Величина подачі води у водогоні насосами свердловин водозабору і подача води підвищувальною насосною станцією переважно не збігаються, тому тиск води у водогоні змінний. Обґрунтовано доцільність експлуатації свердловин у режимі з перервою роботи насосів свердловин на 2 год за добу. Відтак водогін, у межах водозабірних свердловин, спорожниться і режим роботи свердловинних насосів буде в області малих напорів та більшої подачі води. Внаслідок цього зменшиться витрата електроенергії. Виконано порівняння економічності експлуатації насоса ЕЦВ 12-255-30 та насоса SP 270-1L-G. Запропонований режим роботи свердловин дає можливість зменшення експлуатаційних витрат електроенергії.

Based on the comparison and analysis of the economic characteristics of transformers in an operating substation

The technical parameters of transformer are the basic data for analyzing and calculating the comparative analysis of transformer economic characteristics, The comparative analysis of transformer economic characteristics is to seek for reducing transformer active power and improving its operating efficiency, That is to reduce the transformer loss rate, And reduce the reactive power loss of the transformer. The active power loss, reactive power loss and integrated power loss of transformer are calculated. The quantitative calculation formula of economic operation mode of transformer in substation is obtained through analysis, The economic operation mode arrangement and load adjustment can be carried out for the transformer of a certain substation, The purpose of economic operation of transformer and reduction of network loss can be achieved.

Experimental Study on Melting Process in an Industrial Level Molten Salt Tank

Thermal energy storage (TES) is an important part of concentrating solar power (CSP) plants. The primary advantage of TES in CSP plants is the ability to dispatch electrical output to match peak demand periods and reduce the levelized cost of electricity. The major challenge of the molten salt is its high freezing point, leading to additional complicating freeze protection. This paper presents the experimental results of melting process of a mixed nitrate salt with a melting temperature of 115°C in a 20 m3 industrial level tank. Twenty electrical heaters inside the tank are used to heat the salt with a total maximum input power of 240 kW. In order to ensure a safe and fast melting process, the whole process adopted an operating strategy of combining automatic control with manual control. The whole melting process lasted for 314 hours. The salt temperature showed the greatest increase in the first 38 hours. Finally, an economic operation mode of molten salt heat storage tank was obtained.

MODELING THE FLOW DISTRIBUTION AND CONTROL VODOPJANIKHA STATIONS ON MASTROIANNI STAGE

In this article the tasks of modeling the flow distribution are considered, and since the consumers of this system are pumping stations, the first place is put forward not social (as in the second rise), and economic (energy) criteria. The water pressure at the pump inlets is determined by the geodesic levels of the pumps. In wells can be installed various pumping equipment, different in pressure and performance, resulting in a significant difference in the pressure produced by the pumping equipment. In the wells can be installed various pumping equipment, different in pressure and performance, as a result of which there is a significant difference in the pressure generated by the pumping equipment. The article presents a transformed version of the nonlinear and linear models of operational management as applied to water-lifting stations. The governance model allows tracking the transition of the system to a new state and the change of parameters along individual lines within this transition. Herewith, if from two wells the water supply to the manifold increases in accordance with a given forecast, then from the third - the water supply decreases. According to the results of modeling of water supply stations can be built throttle characteristic. The synthesis of throttle characteristics obtained on the basis of the operational control model allows for the operational control of the water supply modes to the clean water tank, which is an alternative to direct modeling. Both methods can be implemented as part of the operation of automated control systems for pump stations I and II lifting. The most interesting is the scheme of water supply stations without back pressure with the predominant location of wells with less powerful submersible pumps closer to the area of low pressures in the collector nodes. The results of numerical simulation are presented in the form of throttle characteristics, that is, the dependence of the flow rate of water supplied from a well by a submersible pump through a choke, on its hydraulic resistance coefficient. Due to the throttle characteristics, it is possible to determine the extremely high value of the water flow entering the clean water tank, as well as the possibility of modeling the most economical mode of operation of wells.