Power storage unit of DC electric railway

Abstract

To prevent invalidated regeneration of an electric vehicle and to protect an electric double layer capacitor against overvoltage without requiring a load resistor facility and without increasing the capacity of a capacitor in a power storage unit where electric power supply to a powering electric vehicle and absorption of regenerated power are performed by charging / discharging an electric double layer capacitor using a step up / down chopper. The electric vehicle (2) has a function for reducing a regeneration current from 100% to 0% at the pantograph point voltage of a specified level or above according to that voltage. The control section (4C) of a step up / down chopper (4B) performs invalidated regeneration prevention control for increasing the feeder voltage up to such a level as to actuate regeneration current reducing control function of the electric vehicle (2) when an electric double layer capacitor (4A) is charged up to an arbitrary voltage.

Description

technical field [0001] The present invention relates to an electric power storage unit of a direct current electric rail system that supplies electric power to electric cars and absorbs the regenerated electric power; more particularly, relates to preventing electric cars from regenerative failure when the electric power storage medium is charged to a level exceeding an arbitrary voltage storage unit. Background technique [0002] Generally, not all of the regenerative power generated by the electric vehicle under regenerative braking is used to start and / or accelerate the vehicle, and thus, the unused regenerative power becomes redundant power. In order to obtain effective utilization of excess regenerative power, a system is proposed in which a power storage unit including a power storage medium and a DC / DC converter is provided in parallel with the feeder cable so that the excess regenerative power is absorbed by the power storage medium absorb. [0003] One disadvantag...

AI Technical Summary

Problems solved by technology

However, in this system, the voltage of the feeder cable cannot be lowered if there are no other trams running under electric power

Therefore, in this measure, it is not always possible to reliably protect the capacitor from overvoltage caused by the regenerative power generated by the electric car, and this protection is affected by other operating conditions of the electric car

In addition, when the feeder substation is of a type without devices or functions to control its output voltage such as tap transformers and semiconductor power converters, the above measures are not practical unless a new feeder substation is installed

Therefore, electrical equipment that can practically use the system in Patent Document 2 is limited; thus, if the electrical equipment is of a type that cannot practically use the system, these electrical equipment need to be replaced, which requires a high equipment cost

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