Introduction and Practical Use of Energy Storage System with Lithium-ion Battery for DC Traction Power Supply System

In order to absorb the regenerative power and to reduce the peak input power of a train-in other words, to smooth the input power of the train-in this paper we repot a frequency-domain-based power controlling strategy for energy storage of hybrid electric railway vehicles. Applying a loss-compensating method by using a disturbance observer improves the energy while keeping ability of this controller. However, that loss compensating method requires precise voltage-energy characteristics of the supercapacitor (SC) to estimate the correct loss. Hence, nonlinearity of the capacitance of the SC becomes a problem because it causes an error in the estimated loss. Therefore, this paper presents a method to measure the voltage-energy characteristics precisely of the SC that has a voltage dependence on the capacitance. A method to implement those characteristics into controllers is also proposed. The loss compensating method is applied to a controller by using the proposed method, and its effectiveness is verified by a small-scale experimental system.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Implementation method of loss observer to power controller for overhead line and supercapacitor hybrid electric railway vehicle

Saito

Kondo

2016

“…Furthermore, as the DC traction power supply system is a low‐voltage/high‐current system, as mentioned in Section 2.2, the transmission distance of high‐current regenerative power is limited. For effective utilization of residual regenerative power, regenerative inverters and energy storage systems are used in DC traction power supply systems in Japan .…”

Section: Peculiarities Of Railway Systemmentioning

confidence: 99%

Recent trends in power electronics applications as solutions in electric railways

Hayashiya

Kondo

2020

Self Cite

Certain applications of power electronics for railway vehicle traction systems and fixed installations are reviewed and future possibilities considering technical and social trends around railway industry are mentioned in this paper. First of all, some particularities of railway load and traction power supply system are summarized as problems to be solved by power electronics technologies. Such technologies for fixed installations and vehicle traction systems are presented and future possibilities for higher performance, minimization, and improved resilience of railway system are pointed out. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

“…Urban rail transit as an effective measure to solve the contradiction between passenger supply and demand with the advantage of green, convenient, fast and large-capacity has become the main investment and development direction of modern urban construction [1,2]. The DC power supply is generally accepted by urban railway transit system.…”

Section: Introductionmentioning

confidence: 99%

Modeling and Analysis of Transformer DC Bias Current Caused by Metro Stray Current

Zhang

et al. 2020

The metro stray current leaked during the subway operation causes the nearby earth surface potential to change, so that the various neutral‐grounded transformers to be at different earth surface potentials, resulting transformer DC bias. In order to analyze the influence of metro stray current on transformer DC bias, the polarization potential monitoring data in metro traction power supply system and neutral point current of nearby transformer were compared, and the positive correlation characteristics between the two were pointed out. By studying the stray current leakage reason in the metro traction power supply system and the circulation path causing transformer DC bias, the mechanism of the transformer DC bias under the subway operating environment was revealed. Based on the discrete model of the stray current distribution, considering the mechanism of stray current on DC bias, the equivalent resistance model of the transformer DC bias caused by metro stray current was built with double‐end power supply environment. Then the calculation formula of transformer neutral point current changing with subway operating conditions was derived, the numerical calculation of DC bias current of transformer caused by metro stray current was realized. The validity of the proposed model was verified by current distribution, electromagnetic field, grounding and soil structure analysis, the simulation results showed that the proposed model can calculate the stray current distribution and the nearby transformer DC bias current with high accuracy, which provided a quantitative analysis method for studying the correlation between metro stray current and transformer DC bias phenomenon. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.