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.

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.

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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.

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.