Distributed Power Supply System Research Articles

Testing Algorithms for Controlling the Distributed Power Supply System of a Railway Signal Box

Trends in the use of renewable energy sources to power buildings do not bypass objects for which maintaining a power supply is critical. This also applies to railway signal boxes. The aim of the research work was to test the multisource power supply system for a railway signal box with power electronic converter systems and a DC bus, built as part of the research project. The assumption for powering the railway signal box building was to use renewable sources, energy storage devices, and a 3 kV DC traction network as the second required power supply grid. Both power grids were connected by power electronic converters, and the power values of the converters were set based on the calculated power balance values using the values measured at the system nodes and the set constraints. The tests primarily tested the response of the power supply system to changes in load power and power generated by the photovoltaic source, as well as the charge level of the energy storage devices. The correctness of the control algorithm’s operation was assessed based on the recorded power values in the power supply system nodes. The tests were carried out for 60 scenarios that covered all normal and emergency operating conditions. During the tests, delays in response to changes in the power supplied to the converters and the values of circular power flow between the power grid connections were recorded. The recorded delays ranged from 2 to about 50 s and the circular power flows did not exceed 1500 W. Based on the results of the tests, it was found necessary to improve the power measurement system in the power supply system nodes and to improve the quality of communication and the transmission time of measurement data transmission time.

Визначення проєктних параметрів системи керування енергетичних космі-чних апаратів для безконтактного живлення космічної індустріальної платформи

The study of the features of near-Earth space industrialization is a promising line in space science. The scientific development of this line is rather deep, and it is carried out both at a theoretical conceptual level and at an experimental level by trying various technological processes onboard the International Space Station. One of the lines of this concept is the study of the features of designing a power system for a space industrial platform. The power system is of the distributed type, which provides for the combined use of power generation modules onboard the space industrial platform itself and an orbital constellation of power spacecraft. In its turn, the use of power spacecraft with contactless electric power transmission to a space industrial platform is intended for highly power-intensive technological processes. In view of the aforesaid, the goal of this paper is to study the features of controlling the power spacecraft of the distributed power supply system of a space industrial platform in such a way as to provide the synchronization of their operating modes with the operation sequence of the space industrial platform. A power spacecraft’s angular motion controllers are synthesized for a solar battery charging mode, a receiving spacecraft aperture pointing mode, and a waiting mode. Methodological recommendations are given on synthesizing the operation schedules of the power spacecraft of the distributed power supply system in such a way as to provide their synchronization with the operation schedules of the space industrial platform. The design parameters to be chosen in designing spacecraft for contactless power transmission to a space industrial platform are identified.

Design of Power Supply for Distributed Aero-engine Intelligent Control System

Compared with centralized power supply system architecture, distributed power supply architecture can better meet the requirements of distributed aero-engine intelligent control systems. The design of distributed power supply topology plays a vitally important role in the distributed power supply system. The paper presents an engineering design method of distributed power supply for the distributed control system in a certain aero-engine. The distributed power supply topology is developed. Based on this topology, the bus voltage level and the current of the distributed intelligent nodes are designed. The optimal selection method of transmission cable types between intelligent nodes is also provided based on the equivalent circuit of a distributed power supply system. The results show that the cable transmission loss and voltage drop meet the design specifications of electrical cable. The proposed distributed power scheme for the distributed engine control system results in minimal modifications, smaller transmission current, and lighter cables.

Design of voltage stabilizing control for a hybrid microgrid with state constraints based on the switching system

With the application and development of new energy generation technology and distributed power supply system, AC-DC hybrid microgrid has the comprehensive advantages of AC microgrid and DC microgrid, and it is significant to study the voltage stability of hybrid microgrid. Based on the switching system theory, the voltage stability control of the ac-dc hybrid micro-grid in grid-connected and the off-grid operation mode are studied in this paper. Considering that the AC and DC bus voltages of the microgrid are constrained in practical engineering applications, the Backstepping controller is designed by using the barrier Lyapunov function and Backstepping method. Considering that the equivalent resistance in the system can not be accurately measured and combined with adaptive control, it is more practical for practical engineering applications.

Restoration Strategy of Distributed Power Supply in Distribution Network Based on Genetic Algorithm

Nowadays, the penetration of distributed power in distribution network increases the complexity of power supply restoration. For the recovery of the traditional method in the field of distributed power supply system restore deficiency, the improving measures are put forward based on the many kinds of operation constraints, proposes the mathematical model of multi-objective optimization. In addition to conventional constraints in the mathematical model, will also be the network structure and branch power flow constraints into consideration. In view of the model, using the rough set theory, a multi-objective optimization problem into a single objective problem, and on this basis, considering the characteristic of radial network and the characteristics of the different load, by using genetic algorithm to reconstruct network, finally through the corresponding example recovery strategy is feasible and efficient.

Analysis of Energy Losses in the Novel Distributed Power Supply System for Trams

The traction substation in conventional power supply systems for trams is a bottleneck of the system. It requires the connection with medium-voltage grid, demands high values of instant power and its centralized topology generates additional energy losses. Since the availability of low-power photovoltaic (PV) generation is increasing in the utility system, we propose to replace conventional substations with a distributed system of low-power devices cooperating with low-voltage grid and PV installations owned by individual households. The proposed in this article distributed power supply system for trams (DPSS-T) consists of multiple traction aggregators (TAs) equipped with energy storage devices (ESDs) which are distributed along the tram line. In order to evaluate the benefits of applying DPSS-T this proposed system was compared with the conventional topology regarding the energy losses in terms of annual operation. Moreover, the following aspects have been studied for the wide range EDS sizes and PV generation: PV energy injection into the power utility system, the utilization of installed ESD, and the contribution of PV generation in energy consumed by traction vehicles. At the same time, the energy management for this new topology has been proposed. The ESDs are charged with relatively low power, between tram runs and discharged with full power during the runs. The suggested energy management eliminates peaks in substation power demand. The obtained results show that despite the fact that the proposed DPSS-T is supplied from low-voltage grid the energy losses are reduced by 58%–69%.

A Phase-Shift Control Method of Triple-Active-Bridge Converter for Reducing Power Loss Under Light Load Condition

This paper presents a phase-shift control method of a triple-active-bridge converter for distributed power supply systems with multiple batteries. The experimental results show that the reactive power through the transformer can be suppressed under a wide range of conditions. The proposed phase-shift control method improves the light load loss at 500W by approximately 30% compared to the conventional method. In addition, according to the power-transmission characteristics of the proposed method, for applications in which a voltage source connected to an input port is attached and detached, the power supply and demand can be adjusted between each output port while gradually lowering the charge of the input port by utilizing the characteristics of the charging operation. Therefore, the converter can continue to operate regardless of the attachment and detachment of the input port-voltage source.

Recent advances in polyaniline-based micro-supercapacitors.

The rapid development of the Internet of Things (IoTs) and proliferation of wearable electronics have significantly stimulated the pursuit of distributed power supply systems that are small and light. Accordingly, micro-supercapacitors (MSCs) have recently attracted tremendous research interest due to their high power density, good energy density, long cycling life, and rapid charge/discharge rate delivered in a limited volume and area. As an emerging class of electrochemical energy storage devices, MSCs using polyaniline (PANI) electrodes are envisaged to bridge the gap between carbonaceous MSCs and micro-batteries, leading to a high power density together with improved energy density. However, despite the intensive development of PANI-based MSCs in the past few decades, a comprehensive review focusing on the chemical properties and synthesis of PANI, working mechanisms, design principles, and electrochemical performances of MSCs is lacking. Thus, herein, we summarize the recent advances in PANI-based MSCs using a wide range of electrode materials. Firstly, the fundamentals of MSCs are outlined including their working principle, device design, fabrication technology, and performance metrics. Then, the working principle and synthesis methods of PANI are discussed. Afterward, MSCs based on various PANI materials including pure PANI, PANI hydrogel, and PANI composites are discussed in detail. Lastly, concluding remarks and perspectives on their future development are presented. This review can present new ideas and give rise to new opportunities for the design of high-performance miniaturized PANI-based MSCs that underpin the sustainable prosperity of the approaching IoTs era.

Модель керування рухом космічних розподілених енергетичних систем

The goal of this article is to develop a generalized mathematical model for controlling the motion of the spacecraft of a space industrial platform’s distributed power system. Space industrialization is one of the promising lines of industrial development in the world. The development of space industrial technologies will allow one to solve a number of problems in the production of unique products unavailable under terrestrial conditions. The main types of these products include semiconductor materials, materials made by 3D printing in microgravity, space modules of sunshade systems, space metallurgy products, space debris processing products, and high-purity space biology substances. Taking this into account, a certain amount of electricity is required for the manufacture of one or another product. Given that some space industrial processes can consume a significant amount of electricity, a space industrial platform's own power generation may not be sufficient. Because of this, it was proposed to use additional energy resources through the development of a distributed power supply system for a space industrial platform. A group of power spacecraft is envisaged to collect and accumulate electric energy and transmit it in a contactless way to the receivers of the space industrial platform. The article presents mathematical models for the analysis of the orbital, angular, and relative motion of power spacecraft and receiver spacecraft. Algorithms are proposed for calculating the parameters of the power spacecraft orientation and stabilization system. A generalized model is constructed for determining the maximum distance and time interval of power spacecraft to platform electric power transmission using microwave radiation. The model developed allows one to choose the power spacecraft design parameters at the stage of conceptual design of space industrial platform power systems.

Research on source-load frequency response control strategy of distributed generation system

Abstract Distributed power generation, as an effective form of new energy power generation, has attracted extensive attention. However, due to the lack of physical inertia support, the stability of the distributed power supply system is threatened. Aiming at the problem of low inertia and weak damping in distributed systems, a source-load frequency response control strategy is proposed in this paper. Firstly, this paper introduces the structure and working mode of the distributed power generation system, and the system frequency characteristics are theoretically analyzed. Then, based on the operating characteristics of the conventional power system, the generator is simulated through the distributed power generation, the load-side converter is coupled to the grid frequency and further the source-load frequency response control strategy is achieved that taps the potential of frequency adjustment capability of the load side through frequency coupling control to provide auxiliary inertia support for the system, and this paper illustrates the source-load frequency adjustment response mechanism in detail. Compared with the conventional single frequency response control, the control strategy proposed in this paper can effectively alleviate the frequency adjustment pressure of distributed units, reduce the capacity of energy storage equipment due to frequency adjustment and improve the efficiency of system operation. Finally, through the simulation analysis of the distributed power generation system, the effectiveness of the control strategy proposed in this paper is verified.

Energy Characteristics of the DC Distributed Power Supply Systems

Currently the circuit technology of the DC traction power supply system cannot provide the necessary requirements for introduction of high-speed traffic. Numbers of measures and tools have been developed to improve the traction lines that no longer meet current requirements. One of the most promising means for strengthening the traction DC lines is transition to the distributed power supply of the rolling stock. In this article, a comparative analysis was carried out of energy indicators of the classic centralized power system and distributed power systems with use of one aggregate traction substation and with use of the solar generators. That comparative analysis of these systems was performed on a simulation model with the same parameters of the traction line and rolling stock.

Forecasting the impact on the environment of generating sources in agricultural production

The development of rural electrification is aimed at distributed energy, i.e. availability of autonomous sources of electricity and heat generation. Generation sources can use coal, fuel oil, gas, local and alternative energy sources as fuel and energy resources. This causes additional emissions of pollutants. Prediction of negative impact on the environment depends on the quantity and quality of emissions during the operation of various types of installations that generate electric and thermal energy. The purpose of the study is to select and substantiate the most attractive method for predicting the impact on the environment of generating sources in agricultural production. The widespread introduction of distributed energy using local and renewable energy sources will significantly reduce emissions of pollutants due to a decrease in energy intensity, matching the required load with the capacity of generation sources, using the most energy efficient sources, and widespread introduction of renewable energy sources. In this regard, it is advisable to forecast the impacts by the scenario method considering the implementation of the proposed distributed power supply system. The implementation of measures developed considering the analysis of the forecast of the negative impact on the environment of generating plants in agricultural enterprises will reduce the negative impact on the environment by introducing energy-efficient technologies into the energy balance of the enterprise, as well as increase production by up to 20% and increase sustainability. rural areas.

Smart charging of mobile electric vehicles

The paper proposes to create a digital economy for the development of electric charging networks of mass-use road transport in a business environment, in fact, these are mechanisms of public-private partnership. To go along the path of purchasing electric charging stations of Korean, Japanese, and German manufacturers and placing them for their own money on communications of Federal or territorial highways or in organizations and enterprises of various forms of ownership is a poorly managed and not rational process. It is proposed to move away from the schemes of location of specific electric charging stations and switch to the schemes of non-powered sockets. The technical solution refers to the technical means of electric charging (recharging) of mobile electric vehicles. The goal is to reduce the cost of creating a network electric charging infrastructure for electric vehicles. The technical result is the ability to ensure the charging mode of the electric vehicle directly from the existing distributed power supply system in space, by using the phase state modes of the electric connector cable that is powered or not powered by electric current. Based on the materials of the paper, patents of Russia and Kazakhstan were obtained.

РАЗРАБОТКА МЕТОДИКИ ОПРЕДЕЛЕНИЯ МЕСТА ОДНОФАЗНОГО ЗАМЫКАНИЯ НА ЗЕМЛЮ ВОЗДУШНОЙ ЛИНИИ ЭЛЕКТРОПЕРЕДАЧИ НАПРЯЖЕНИЕМ 6(10) кВ С УЧЕТОМ КЛИМАТИЧЕСКИХ ФАКТОРОВ

Актуальность. Одной из основных причин высокой аварийности и отключений в распределенных системах электроснабжения 6(10) кВ кустов нефтяных скважин являются повреждения воздушных линий электропередачи вследствие однофазных замыканий на землю. Широко проводимые исследования по определению места возникновения однофазного замыкания на землю установили корреляцию между точностью определения и большим количеством изменяющихся факторов, таких как параметры режима работы, параметры воздушной линии электропередачи, вид повреждения, величина переходного сопротивления, сопротивление грунта и прочие, принимая их усреднённые значения, не зависимо от изменения климатических условий. Нормирование технических средств определения места возникновения однофазного замыкания на землю по инструментальным погрешностям без учёта методической составляющей обуславливает погрешность определения места повреждения, достигающую 30 %. Таким образом, актуальны исследования, направленные на определение первичных параметров ЛЭП и минимизацию методической погрешности определения места повреждения ЛЭП с учётом климатических факторов. Цель исследования заключается в повышении точности определения места возникновения однофазного замыкания на землю линии электропередачи 6(10) кВ путём разработки методики, учитывающей влияние климатических факторов. Методы. Учтены основные физические процессы распространения электромагнитной волны в линии электропередачи. Использованы основные положения теории электрических цепей и электромагнитного поля; алгоритмы пакета MATLAB Simulink. Результаты. Разработан алгоритм, позволяющий определить расстояние от понижающих подстанций 6(10)/0,4 кВ до места возникновения однофазного замыкания на землю в распределительных сетях кустов нефтяных скважин с учетом конструктивных особенностей линии электропередачи и климатических факторов. Разработана в среде MATLAB Simulink имитационная модель распределительной сети 10 кВ, питающей кусты нефтяных скважин, учитывающая зависимость первичных параметров линии электропередачи от климатических факторов и удельного сопротивления грунта.

Stability Problems in Designing Aggregated and Distributed Systems of Secondary Power Supplies

In this paper, we show that, when operating in the stand-alone mode, self-oscillating modes, due to the interaction of subsystems, are possible in aggregated (composite, complex) power supplies and distributed power supply systems (DPSs) that use the “bus” approach and consist of stable modules with large margins of stability in amplitude and phase of loopback gain of negative feedback. The self-excitation of the system is shown to be due to the complex nature of the input and output impedances and the negative active (real) component of the input impedance of the output DPS subsystem. The negative nature of the active component of the input impedance of the output (load) subsystem with stabilized output voltage, i.e., with negative feedback, is due to the falling nature of its input current–voltage characteristic. The design of aggregated devices and DPSs is shown to require a systematic approach, provided that the properties and interactions of subsystems are taken into account.

Influence of distributed power supply in distributed power distribution network

In distribution networks with distributed power supplies, distributed power supplies can also be used as backup power sources to support the grid. If a distribution network contains multiple distributed power sources, the distribution network becomes a complex power grid with multiple power supplies. When a short-circuit fault occurs at a certain point on the power distribution network, the size, direction and duration of the short-circuit current are no longer single due to the existence of distributed power, and will vary with the location and capacity of the distributed power supply system. The change, in turn, affects the current in the grid, resulting in the generation and propagation of additional current. This power grid of power electronics will cause problems such as excessive standard mis-operation, abnormal heating of the converter and component burnout, and communication system failure. It is of great and practical significance to study the influence of distributed power in distributed power distribution networks.

Development of a method for determining the location of a single line-to-ground fault of an overhead power line with voltage of 6(10) kV considering climatic factors

One of the main causes of the high accidents and outages rate in 6(10)-kV distributed power supply systems of oil well clusters is damage to overhead power lines due to single line-to-ground faults. Widely conducted studies to locate a single line-to-ground fault have established a correlation between the accuracy of determination and a large number of changing factors, such as operating mode parameters, overhead power line parameters, type of damage, transition resistance, soil resistance, and others. Rationing of technical means for determining the location of a single line-to-ground fault by instrumental errors without taking into account the methodological component translates into the error in locating the damage up to 30%. Thus, relevant research is aimed at determining the primary parameters of power lines and minimizing the methodological error in determining the location of damaged power lines, considering climatic factors. The study takes into account the basic physical processes of propagation of an electromagnetic wave in the power line. The main principles of the theory of electrical circuits and the electromagnetic field and MATLAB Simulink package algorithms are used. As part of the study, a technique has been developed that allows determining the distance from 6(10)/0.4-kV substations to a single line-to-ground fault location in distribution networks of oil well clusters taking into account climatic factors. A simulation model of a 10-kV distribution network supplying oil well clusters was developed in MATLAB Simulink, taking into account the dependence of the primary power line parameters on climatic factors and soil resistivity.

A Nonlinear Controller Based on a High Gain Observer for a Cascade Boost Converter in a Fuel Cell Distributed Power Supply System

This study aims to design a controller for a cascade boost converter connected to a fuel cell in a distributed generator system. Knowing that the fuel cell voltage is too low to satisfy load requirement, and it varies with a nonlinear manner depending on the load current with uncertainties lying on fuel cell operating conditions, we use a DC converter to step up the low voltage and find out a control law to regulate the converter output voltage. Here, a lyapunov stability technique is used to design the nonlinear controller. An average current mode control method is adopted to satisfy the above objective. Moreover, a high gain observer is developed to estimate the converter output current instead of to be captured. Besides, the cascade boost converter is proved to be more suitable for high DC link voltage compared to a single boost converter. Theoretical studies and simulation using Matlab Simpower System tools show that the adaptive controller meets the objectives for what it is designed.

Studying of the power modes in the traction line for ensuring the high-speed traffic

The object of research is the power regimes in traction power systems for both centralized and distributed power when introducing high-speed traffic. The introduction of high-speed traffic on electrified railways of Ukraine has begun a number of restrictions in the applied system of traction power supply of centralized power supply. These include not only the impossibility of providing the necessary voltage level of 2.9 kV, but also the low efficiency of the aggregate power of traction substations. In this case, the applied traction power system does not allow to provide the necessary level of specific power in the traction network. Applicable technical means and measures to strengthen the traction network do not allow, in most cases, to provide regulatory requirements for the organization of high-speed traffic. An analysis of modern research shows that overcoming these disadvantages is possible due to the application of a distributed power supply system to the traction network. To date, sufficient options have been developed for constructing such systems, but in this paper, as an alternative, a system was considered with the distribution of the aggregate power available in the system of centralized power in the inter-substation zone. At the same time it was reasonable to reduce the power of the traction substation to the level of 10 MW. During the study of power regimes in comparable traction power systems, the results of experimental studies and simulation modeling of the operating modes of the comparable systems were used. Calculations were taken into account not only the specifics of the traction load, but also its impact on the load capacity of the contact suspension. As a result of this approach, it has been shown that the distributed traction power system allows to fulfill the regulatory requirements for providing high-speed traffic. With its application, the consumption of electric energy for traction of trains is reduced by 40 %, the specific power of traction network increases by 90 %, and the load factor of traction substations – by 60 %. The proposed innovative approach to providing the necessary power mode in the traction line for the organization of high-speed traffic allows to preserve the existing infrastructure on existing electrified section of direct current. This approach allows the application of various types of electric rolling stock and provides the required capacity of the railways.

PERSPECTIVE TRANSPORT-POWER SYSTEM BASED ON THE INTEGRATION OF MAGLEV-TECHNOLOGY AND DISTRIBUTED PHOTO-ELECTRIC STATION

Purpose. The research main purpose is the perfection of magnetolevitating technology on electrodynamic suspension and providing its functioning on the base of ecologically rational energy systems. It means creation of the MAGLEV transport-power system which uses renewable energy sources (in particular, photoelectric converters) and is connected to national/local networks as an energy user and producer simultaneously. Methodology. Conducted research, analysis and summary conclusions are based both on the results of works on the given subject, and own works of authors. The methods of systems analysis and computer design of components of the large cyber-physical transport-power system were used during research conducting. Findings. The physical-technical foundations of conception of the perspective transport-power system, which includes high-speed ground vehicle on electrodynamic suspension and distributed photo-electric energy complex are developed. The adapt to the performance of the given transport type and guaranteeing its safe functioning in any weather terms. Originality. For the first time authors substantiated the possibility for creation of single transport complex uniting the speed magnetolevitating system and distributed power supply system on the base of sun energy. It is simultaneously the inalienable part of the precision fast-acting control system, working in the real-time mode. Practical value. The offered scientific-technical solution allows on the base of renewable energy source to solve the problems of power supply and a high-speed transport control. Due to the inclusion of the distributed power supply system into local intellectual networks on the SMART-grid technology it gives the possibility to optimize energy consumption of territories neighboring to high-speed way.