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Zhongping Yang

Bio: Zhongping Yang is an academic researcher from Beijing Jiaotong University. The author has contributed to research in topics: Regenerative brake & Energy storage. The author has an hindex of 6, co-authored 50 publications receiving 125 citations.

Papers
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Journal ArticleDOI
TL;DR: Simulation and experimental results show that the proposed cooperative control strategy for multiple ESSs based on multiagent deep reinforcement learning optimizes the energy distribution between different SCESSs and trains, and improves the overall energy saving effect of the multi-SCESSs.
Abstract: Nowadays, the stationary energy storage systems (ESSs) are widely introduced to recover the regenerative braking energy in urban rail systems. And the multiple ESSs along the line, substations, traction, and braking trains in the traction power system make up a multienergy coupling system, whose energy efficiency is expected to be improved. With the aim of power flow optimization, a cooperative control strategy for multiple ESSs based on multiagent deep reinforcement learning is proposed in this article. Under the distributed control structure, the decision process of multiple ESS agents is formulated as a fully cooperative Markov game, in which each ESS makes independent decision and cooperates to improve the overall energy saving effect. And the value decomposition network, which decomposes the joint state-action value into value functions across agents, is adopted to stabilize the multiagent learning process. Three train operation scenarios are presented in simulation, and the power flow distributions are analyzed quantitatively to better evaluate the performance of the proposed cooperative strategy. A power hardware-in-the-loop (PHIL) experimental platform, which integrates the RT-LAB simulator and physical supercapacitor-based energy storage system (SCESS) is developed in this article to emulate the dc traction power system with multitrain operation. Based on the PHIL platform, the proposed cooperative control strategy is implemented experimentally. Both simulation and experimental results show that in comparison with genetic algorithm (GA), the proposed strategy optimizes the energy distribution between different SCESSs and trains, and improves the overall energy saving effect of the multi-SCESSs.

47 citations

Journal ArticleDOI
27 Sep 2018
TL;DR: In this paper, common data-driven prognostic methods for IGBT RUL are summarized and four common problems of these schemes are presented and discussed.
Abstract: Power converters with insulated gate bipolar transistor(IGBT) are widely used in diverse industrial applications such as traction systems. As the IGBT is one of the most fragile components in power electronics converter, remaining useful life(RUL) prognostic of IGBT is important to guarantee system reliability. This paper presents a review of data-driven prognostic for IGBT RUL. In this paper, common data-driven prognostic methods are summarized. Features of data-driven prognostic approaches of IGBT are discussed, and main approaches are compared to each other. Four common problems of these schemes are presented and discussed. In addition, some other desirable studies to improve IGBT RUL estimation are proposed.

33 citations

Journal ArticleDOI
TL;DR: The results show that the proposed BESS control strategy can effectively realize energy transfer and achieve energy saving and voltage stability, and also can effectively reduce the peak power of traction substation, bring more economic benefits.
Abstract: In order to reduce the peak power of traction substation as much as possible and make better use of the configu-ration capacity of battery energy storage system (BESS) in urban rail transit, a BESS control strategy based on energy transfer is proposed. Based on the actual subway line data, the load characteristics of urban rail transit with different departure intervals are analyzed by using the simulation platform of urban rail transit traction power supply system. Then, based on the characteristics of urban rail traffic load and the high energy density of the battery, the SOC dynamic adjustment module and discharge threshold dynamic adjustment module were added. The discharge threshold is dynamically adjusted according to the SOC of the battery, and part of regenerative braking energy absorbed by the energy storage device is transferred from off-peak/flat peak period to peak period for release. The simulation model and 90 kW physical platform are used to verify the proposed control strategy, and the results show that the control strategy can effectively realize energy transfer. Not only can achieve energy saving and voltage stability, but also can effectively reduce the peak power of traction substation, bring more economic benefits.

30 citations

Journal ArticleDOI
TL;DR: By coordinated control with a wayside supercapacitor, the residual regenerative braking energy can be absorbed even in special cases, and this strategy can effectively reduce the system loss by adjusting the DC voltage on the inverter-side.
Abstract: In order to absorb the regenerative braking energy of trains, supercapacitor energy storage systems (ESS) are widely used in subways. Although wayside ESS are widely used, because of the influence of no-load voltage, and so on, a wayside ESS cannot absorb all the regenerative braking energy in some special cases, and the brake resistor is still activated, which leading to the wasting of energy. In order to completely replace the on-board brake resistor, this paper configures a certain on-board super-capacitor, and based on a DC-side series super-capacitor topology, proposes a hierarchical optimization energy management strategy (EMS). The EMS is divided into three layers: Firstly, the strategy can increase the inverter-side voltage in a short time without changing the traction network voltage, and improve the train braking characteristic curve by utilizing the short-time overvoltage capability of the inverter and the motor; Secondly, by coordinated control with a wayside supercapacitor, the residual regenerative braking energy can be absorbed even in special cases; Finally, based on loss calculation and current prediction, this strategy can effectively reduce the system loss by adjusting the DC voltage on the inverter-side. The proposed control strategy is validated through RT-LAB experiment, and the experimental results agree well with the theory.

20 citations

Journal ArticleDOI
TL;DR: This article proposes a rolling optimization strategy (ROS) based on wavelet neural network prediction and dynamic programming (DP) for tram equipped with on-board battery-supercapacitor hybrid energy storage system, and proves the rationality of using RB strategy to replace ROS strategy entirely or partially in some scenarios.
Abstract: This article focuses on the optimization of energy management strategy (EMS) for the tram equipped with on-board battery-supercapacitor hybrid energy storage system. The purposes of the optimization are to prolong the battery life, improve the system efficiency, and realize real-time control. Therefore, based on the analysis of a large number of historical operation data, this article proposes a rolling optimization strategy (ROS) based on wavelet neural network prediction and dynamic programming (DP). Furthermore, this article makes condition construction by analyzing the operation characteristics of the tram, and proposes a hybrid EMS based on line prediction and condition analysis, and the strategy makes a cross use of ROS and rule-based (RB) for simplification, and the parameters in the strategy are optimized. Through the analysis of practical cases, three substrategies are verified respectively, and they show obvious optimization effect on the objective, and compared with the whole process DP, the proposed strategy obtains real-time optimization. At the same time, it proves the rationality of using RB strategy to replace ROS strategy entirely or partially in some scenarios.

16 citations


Cited by
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01 Jan 1992
TL;DR: In this paper, a multilevel commutation cell is introduced for high-voltage power conversion, which can be applied to either choppers or voltage-source inverters and generalized to any number of switches.
Abstract: The authors discuss high-voltage power conversion. Conventional series connection and three-level voltage source inverter techniques are reviewed and compared. A novel versatile multilevel commutation cell is introduced: it is shown that this topology is safer and more simple to control, and delivers purer output waveforms. The authors show how this technique can be applied to either choppers or voltage-source inverters and generalized to any number of switches.<>

1,202 citations

01 Jan 1976
TL;DR: In this paper, an exact and an approximate method for calculating the probability of occurrence of the output event from priority-and (sequential) failure logic is given, which can be used during fault-tree analysis without modification to existing quantitative evaluation techniques.
Abstract: An exact and an approximate method for calculating the probability of occurrence of the output event from priority-AND (sequential) failure logic is given. The approximate method can be used during fault-tree analysis without modification to existing quantitative evaluation techniques. Assumptions made include s-independent, exponentially distributed, non-repairable basic events as input to the priority-AND failure logic.

87 citations

Journal Article
TL;DR: In this paper, a flux-weakening control method based on rotor flux orientation is presented to improve the current tracking capability and output characteristics of the motor torque, and the method is implemented in digital ac spindle driver system.
Abstract: In this paper,a new flux-weakening control method based on rotor flux orientation is presented to improve the current tracking capability and output characteristics of the motor torque,and the method is implemented in digital ac spindle driver system.Using Labview virtual oscilloscope to observe the real-time experimental data,the experimental results show that the method can effectively improve the dynamic response of motor as well as the output characteristics of the motor torque.

81 citations

Journal ArticleDOI
01 Jan 2021
TL;DR: In this article, an alternative straightforward technical route, embedded in the cyber-physical-social system framework, is proposed to evaluate the impact of the detected fault on the plant-wide performance.
Abstract: The intensive research and development efforts directed towards large-scale complex industrial systems in the context of Industry 4.0 indicate that safety and reliability issues pose significant challenges. During online operation, system performance degradation will lead, not only to economic losses, but also potential safety hazards. In the existing research and technical routes, the target of the fault diagnosis systems is to trigger alarms to report the fact of the existence of malfunctions as well as the underlying reasons accurately. However, it remains unanswered how urgent it is to fix it, and what degrees of fault-tolerance, maintenance, and fault recovery are needed. Further analyses are necessary to evaluate the impact of the detected fault on the plant-wide performance. In this article, to enable a more comprehensive and precise description of the plant-wide operational status, the roles of the commonly used performance metrics, the state-of-the-art performance evaluation approaches, as well as the performance-oriented and plant-wide process monitoring techniques are investigated. On this basis, an alternative straightforward technical route, embedded in the cyber-physical-social system framework is proposed. A roadmap including the key research questions, the future research directions, and an outlook about the future vision is presented.

76 citations