With the continuous growth of demand for heavy-duty railway transportation, the operational energy consumption of its traction power supply system is increasing, and the problem of significant waste of regenerative braking energy in trains is becoming increasingly prominent. To improve the energy efficiency and economy of the system, this paper studies the integration of a hybrid energy storage system consisting of batteries and supercapacitors into the traction power supply system to achieve efficient recovery and utilization of regenerative braking energy. With the goal of reducing the daily operating costs of hybrid energy storage systems and minimizing energy interaction with external power grids, an optimization scheduling model was constructed that comprehensively considers the random scenario constraints of system safety and stable operation. The multi-objective particle swarm algorithm was used to solve the model. The simulation results have verified that the proposed strategy can effectively coordinate the economic operation and electricity autonomy of the system while ensuring system reliability, providing a feasible solution for energy conservation and consumption reduction of heavy-duty railways.

With the development of wireless power transfer technology, dynamic wireless power transfer (DWPT) technology can meet the requirements of "charging while walking" electric vehicles and reduce the waiting time for load charging, so dynamic wireless power transfer has attracted more and more attention from scholars at home and abroad. In this paper, we refer to the literature on DWPT in recent years, introduce the principle of DWPT, analyze and summarize the five aspects of segmented power supply mode, coupling mechanism design, coil detection and switching control mode, system power and efficiency optimization control strategy, and compensation network design, analyze the recent research progress in the above five aspects, and finally summarize and prospect.

Integrating renewables into railway traction power systems via RPC causes instability due to high VSC penetration. Traditional impedance analysis methods are inadequate for these complex, multi-port systems, facing challenges in modeling (frequency coupling, AC/DC coupling) and overly conservative MIMO criteria. This paper presents an improved, low-conservatism stability criterion using the Gerschgorin circle theorem. By utilizing the intersection of two independent circle sets derived from L(s) and L1(s), the method reduces conservatism and enables robust stability analysis of "gray box" systems without solving for eigenvalues.

Against the background of the development of the aviation industry and the intensified demand for flight simulators, the electric steering load system has attracted much attention for its ability to achieve realistic aircraft feedback force sensing and reduce the design and flight training costs. As to how to achieve realistic feedback force sensing of electric steering load system, force sensing servo control has become the key technology to solve the development of flight simulators. However, how to achieve realistic force sensing control of electric manoeuvre load system is still a major challenge. In this paper, the two core objectives of the electric manoeuvring load system, namely realism and stability, are reviewed. Firstly, it briefly describes the current application status and research status of electric load manipulation systems at home and abroad. Then, its basic functions and system models are discussed; in addition, three control strategies of the electric manipulated load system are introduced. Finally, the research direction of force sensing simulation of electric manipulated load system is prospected in the light of the existing control strategies. This review can provide references and insights for future force sensing control of electric manipulated load systems.

This paper proposes a dynamic trend calculation method for traction power supply system of high-speed railroad based on vehicle-network coupling. By establishing the contact network chain equivalent circuit model, external power supply, traction substation, autotransformer and shunt components of the mathematical model, and fully consider the impedance of the traction network caused by the train movement of the dynamic changes, put forward a dynamic chain circuit model that can reflect the real-time power distribution of the train. The voltage and power distribution characteristics of the system under different train operating conditions are investigated by continuous linear current calculation method. Simulation results show that the method can accurately simulate the electrical characteristics of each line in the traction power supply system, and can effectively capture the impact of train position changes on the system voltage and power, verifying the effectiveness and convergence of its application in complex electrified railroad systems. The research in this paper provides an important theoretical basis for further optimizing the design of traction power supply system of high-speed railroads and improving its operational efficiency.

The proposal of dynamic wireless charging (DWC) provides a new idea for the development of new energy vehicles, that is, charging while driving the car to reduce unnecessary waiting time, because in the process of electric vehicle driving, the mutual inductance coefficient between the coils will inevitably change greatly, resulting in the system in an unhealthy working state for a long time and the output power can’t be stabilized within the rated range. In recent years, a large number of research methods have been proposed to address the problem of power fluctuations. These methods can be broken down into three main areas: changing the coil structure, optimizing compensation, and applying a controller to stabilize the output power. In this paper, the mutual inductance and voltage fluctuation problems of dynamic wireless power transfer (DWPT) systems are analyzed, and then the current research progress on magnetic coil structure, compensation network topology and control scheme is expounded, and finally the research progress is summarized and prospected.

With the steady advancement of highway infrastructure, the highway tunnel has been extended to remote areas and mountainous areas. It is difficult to connect to the power grid, the line distance is far, and the construction investment is large. Therefore, the use of distributed photovoltaic system to supply power to the power facilities in the tunnel can effectively reduce the power consumption, save natural resources and promote energy conservation and emission reduction. Based on the shortcomings of the traditional power supply mode of highway tunnel, combined with the application of distributed photovoltaic in highway tunnel in China, this paper analyzes the application advantages of distributed photovoltaic power station for power supply of tunnel lighting system. Finally, taking the actual project as an example, it shows that it has good economic and social benefits.

With the introduction of fractional-order theory, fractional-order circuit theory has shown great advantages in modelling and signal processing, but fractional-order circuits have not yet been deeply studied in the field of wireless power transfer. In this paper, the theory of fractional calculus is introduced firstly, and the fractional capacitance and inductance models are analyzed. On this basis, the current status of the application of fractional-order components and fractional-order circuits is reviewed. Then, the fractional-order wireless power transmission system is introduced, and the fractional-order WPT system is superior to the integer-order WPT system in terms of both fractional-order autonomous circuits and non-autonomous circuits, and finally, the development prospect of the fractional-order WPT system is outlooked.

The traditional way of consuming the regenerative braking energy (RBE) of the suspended train through the braking resistor leads to increasingly prominent problems such as the low utilization rate of the RBE. If we can realize the efficient utilization of RBE in maglev transportation, it will be beneficial to realize energy saving and consumption reduction of maglev traffic and the realization of the 3060 dual carbon goal. This paper analyzes the topology structure and operation principle of the doubly-fed linear motor (DFLM), as well as its energy flow characteristics under different operating states. The topology structure and the corresponding energy management strategy of the RBE utilization system on the stator side, and the feedback energy utilization system on the mover side of the suspended train based on the DFLM are given. The system's feasibility to achieve dynamic power distribution is verified by analyzing the train operating state and the transition conditions between the four operating modes of the stator-side RBE utilization system and the specific operating conditions in the operating mode. A technical method is provided for realizing efficient utilization of the RBE in maglev traffic.

In electrified railways, traction load not only fluctuates between peaks and valleys, but also has a situation of low utilization rate of average load throughout the day and short overload.The traction transformer selects the capacity with the peak load as the demand boundary, which will cause the capacity utilization rate to be low and even lead to the economic decline of the traction power supply system.This article summarizes the existing configuration methods for capacity optimization of traction transformer.Then under the conditions of energy storage and new energy access to traction power supply system, the three aspects are described as follows.Firstly, the energy storage device is connected to the system, which can pull the capacity of traction transformer to achieve peak shifting and valley filling.Then, the possibility of integrated configuration of new energy and traction power supply system to optimize the capacity of traction transformer and the methods of optimal configuration of traction transformer capacity by using new energy such as wind and light are summarized.Finally, this paper discusses the current structure of new energy access to traction power supply system, and it looks forward to the feasibility of new energy access to traction power supply system cooperating with energy storage devices to optimize the capacity of traction transformer.

Recently, the permanent magnet synchronous motor (PMSM) drive system has replaced traditional actuators in more and more occasions, especially in some cutting-edge application areas, the reliability and safety of its drive system are very critical, which requires faults after that, it can detect and solve in time, and even continue to run stably with the failure. Therefore, the fault-tolerant control of the motor through the reconstruction of hardware circuits and software algorithms to ensure the undisturbed operation of the system after a fault has become a hot issue in current research. This article focuses on the four main types of inverter faults, stator winding faults, sensor faults, and permanent magnet demagnetization faults that have the highest failure rates in PMSM drive systems. First, the research results of fault detection and diagnosis technology of PMSM drive system under four fault conditions are described. Then, the research status of active fault-tolerant control technology of the PMSM drive system under different fault conditions are summarized. Finally, the future development of the PMSM drive system fault diagnosis and active fault-tolerant control technology is summarized and prospected based on the research status.

In the bidirectional LCL type Inductively coupled power transfer (ICPT) system; there are a lot of harmonics in the output current of the primary and secondary side inverter bridge. In order to solve the harmonic problem of bi-directional ICPT system, this paper firstly analyzes the harmonic of bidirectional LCL type ICPT, obtains the proportion of each harmonic amplitude to the fundamental amplitude, and determines the third harmonic as the main harmonic. Secondly, the harmonic elimination method of back injection method is applied to bidirectional ICPT system. After the parameters of frequency selection network are determined by calculation, Matlab / Simulink circuit simulation is built to analyze the output current of primary and secondary sides of bidirectional LCL ICPT system before and after adding frequency selection network and back injection channel. The conclusion shows that in the bidirectional ICPT system, Harmonic extraction and anti-injection method also has visible fixed harmonic elimination effect.

For high-speed rail with high energy consumption, the recovery and utilization of regenerative braking energy is essential to improve the energy consumption of high-speed rail. As a technical link, the energy bidirectional feed inductively coupled power transfer (ICPT) system can realize the regenerative braking energy recovery of the contactless traction power supply system. Furthermore, considering that the braking energy of the high-speed rail is the largest when entering the station during the whole line operation, the braking section of the station is mainly considered. This paper proposes a preset control method for segmented power supply of the energy bidirectional feed ICPT system considering regenerative braking energy recovery. By establishing the steady-state mathematical model of the bidirectional ICPT system, the influence of the internal phase-shift angles φ1 and φ2 and the external phase-shift angle γ on the operating state of the system is analyzed. To realize system synchronization under the operation of EMUs, a train braking model is established through force analysis, and a power preset controller is designed to realize the synchronous control of the power flow of the bilateral system. According to the braking process of the train entering the station, the switching control method of the segment coil under the different conditions of the single train entering the station and the multitrain entering the station is proposed to ensure the reliability and flexibility of the train power supply. The simulation results of the 350 kW ICPT system simulation model show that the system can operate stably when the power transmission simulation is switched, and the transmission efficiency can reach 89%, which proves the feasibility of the control method. Energy-saving estimates show that a single train can recover about 200–300 kWh of electric energy during single braking. The comparison with the measured data verifies the accuracy of the modeling in this paper.

The Mobile Contactless Power Transmission (MCPT) system has a large leakage inductance on both sides and the mutual inductance is easy to fluctuate during the operation, which makes the transmission power and efficiency of the system relatively low. This paper considers the influence of load change, quality factor and coupling coefficient of the MCPT system in the movable process and theoretically analyzes the power transmission characteristics of the MCPT system. Then the power and efficiency transfer characteristics of the two basic compensation methods and the two composite methods are given. Finally, the influence curves of transmission power with frequency, mutual inductance, load and coupling coefficient k under two kinds of composite compensation structures are analyzed. The relationship between coupling coefficient, input quality factor Q(i0) and transmission characteristics under moving conditions is obtained. Using Pspice simulation experiment, the correctness of the theoretical analysis was verified and TS-P compensation method is more suitable for MCPT system.

The regenerative braking energy of high-speed railway accounts for about 10% of traction energy consumption, which will be higher under special conditions. The regenerative braking energy feedback of the contactless traction power supply system needs to be realized by dynamic bidirectional inductively coupled power transfer (ICPT). A novel regenerative braking energy distribution method for the contactless traction power supply system based on dynamic bidirectional energy ICPT (DBEI-ICPT) technology is proposed. Then, the mathematical model of the dynamic bidirectional ICPT technology is established; and the variation of transmission power is analyzed; Theoretical analysis of the system energy distribution and its feedback methods. The relationship between the energy flow and the train running state during braking is carried out. After that, an improved train braking curve and control method based on the ICPT technology is proposed, which can satisfy the requirements of the regenerative braking process before the train enters the station by controlling three phase shift angles of the ICPT technology. The control strategy with feedforward control is introduced into the energy storage system to suppress the bus voltage fluctuation. Besides, a nonlinear disturbance observer (NDO) is introduced to solve the shortcomings of the traditional feedforward control methods that require remote measurement. Finally, the effectiveness of the proposed power supply system as well the control strategy is verified by simulation. Results show that the current feedforward bus voltage regulation control is more suitable for this system for its shorter sampling time and stability.

多负载ICPT系统是由一个原边发射线圈与多个副边接收线圈构成的无线电能传输系统,能够为多个负载提供电能.由于系统中存在高频逆变电路,使得系统在离散状态与连续状态间不断转换,所以该系统为典型的混杂系统,而副边接收线圈之间的耦合关系又使得建立的模型不准确.针对上述问题,本文利用LCL-S型三负载ICPT系统模型,首先对副边线圈之间的互感进行解耦,然后确定系统的离散状态并对不同离散状态下的电路工作状态进行分析,建立其状态空间模型,最后利用混杂系统理论对其连续状态与离散状态之间的切换关系进行分析,建立了三负载ICPT系统的混杂自动机模型.通过Matlab/Simulink的Stateflow工具箱搭建了仿真模型,分析了在混杂自动机控制下三负载ICPT系统的稳定性及其传输特性.

The traditional rail transit traction power supply system is susceptible to extreme environmental conditions, resulting in a decrease in its safety and reliability. The contactless power supply technology solves the problems caused by the contact between the electric locomotive and the traction network and provides significant advantages for the new rail transit power supply technology. Inductively coupled power transfer (ICPT) technology has become the best choice for contactless power supply technology for rail transit because of its large transmission power and suitable transmission distance. The bidirectional ICPT system solves the traditional traction power supply problem, and can also return the regenerative braking energy of the electric locomotive to the traction net to achieve peak cutting and valley filling, and achieves energy-saving operation. This paper reviews the commonly used topologies, control methods, modeling and optimization methods and looks forward to the application of these key technologies in rail transit applications at the future.

基于感应耦合电能传输(inductively coupled power transfer,ICPT)的非接触式牵引供电系统可以非接触供电方式为列车提供实时牵引电能,是轨道交通领域未来新型牵引供电技术的重要发展方向。首先,阐述了轨道交通实时受流非接触式牵引供电系统的结构和特点,回顾了ICPT技术和轨道交通非接触式牵引供电系统的国内外研究现状。然后,详细分析了基于ICPT的非接触式牵引供电主要关键技术研究成果和存在的问题。最后,结合研究现状对轨道交通非接触式牵引供电系统研究进行了展望。

A new nonlinear decoupling control method without state feedback based on a generalized inverse system of a least squares support vector machine (LS‐SVM) is proposed for a multiple‐input multiple‐output nonlinear discrete system. According to the mathematical model of multivariable nonlinear discrete systems, the reversibility of the LS‐SVM generalized inverse system is analyzed and verified. Using the ability of LS‐SVM to approximate nonlinear functions, the multivariable nonlinear generalized inverse model of stateless feedback can be obtained offline. The generalized inverse system obtained by LS‐SVM identification is connected before the original nonlinear system to decouple the multivariable nonlinear discrete systems into q independent single‐input single‐output pseudolinear subsystems. The theoretical derivation and simulation results show that the presented LS‐SVM generalized inverse decoupling control method can realize the dynamic decoupling of multivariable nonlinear systems. And the pseudolinear composite systems show good dynamic performance. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

The traditional contact power supply method cannot meet the electric vehicle (EV) charging during driving, so it is very necessary to research the Dynamic Bidirectional-Energy-Interaction-Based Wireless Power Transfer (DBEIB-WPT) technology. The WPT technology solves problems such as contact with the power supply sources and loads. Due to its movable nature, the connects and disconnects of the load will cause a change in frequency. However, because of its characteristic that the electric energy can be bidirectional energy transmission with the grid, the electric energy can be feedback to the grid to achieve the purpose of peak clipping and valley filling. This paper reviews the current common compensation topology, coil structure, a variety of dynamic WPT and control methods. Review the domestic and foreign-related research, and some hot issues of dynamic WPT technology: unidirectional/bidirectional feedback topology, modeling idea, resonance compensation, Vehicle-to-grid(V2G), etc. The analysis of these technologies and methods. Finally, discusses the key technologies and deficiencies of the DBEIBWPT technology.