Railway photovoltaic energy storing system and control method for regenerative braking energy recovery

Abstract

The invention discloses a railway photovoltaic energy storing system and control method for regenerative braking energy recovery. Real-time online detection and processing are carried out on all kindsof running data of a photovoltaic side, traction side and energy storing side, a comprehensive judgement is carried out on running conditions based on a calculation result, control schemes under multiple scenes are selected through a judging result, an energy storing unit is taken as an energy transferring station, the coordinated control of a back-to-back converter, photovoltaic power generationunit and energy storing unit is achieved, and the electric energy elective exchange under the multiple scenes is completed. The system and method are conductive for photovoltaic power energy nearby consumption and railway system green development, can effectively recover the regenerative braking energy of haulage motors and the photovoltaic power energy which cannot be consumed, increases systemeconomic benefits, stabilizes photovoltaic side output and power energy fluctuation of the traction side under the regenerative braking conditions, and compensates for negative sequence functions of atraction power supply system.

Description

technical field [0001] The invention belongs to the technical field of electrified railways, in particular to a railway photovoltaic energy storage system and a control method for regenerative braking energy recovery. Background technique [0002] In recent years, under the background of Energy Internet, various industries have gradually changed the current energy utilization mode to establish a greener, safer and sustainable new energy utilization mode. Among them, the electrified railway system has attracted extensive attention because of its huge energy consumption. Due to the extremely extensive geographical location of the railway network, a large amount of renewable energy is distributed along the way, which provides convenience for its nearby consumption. The advantages of easy decentralized layout are very popular, and some researches have carried out preliminary explorations on the access form of photovoltaic access to traction power supply system. [0003] Since ...

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Problems solved by technology

[0003] Since mainstream AC drive locomotives have regenerative characteristics, megawatt-level regenerative braking electric energy will be generated during the braking process. This part of energy will be used by the locomotive in the traction state in the same electric arm, and the excess part will be directly passed through the traction transformer. Return to the power system, but the current policy of the power sector adopts the punitive charging method of "return and return", which cannot produce direct economic benefits

At the same time, during the photovoltaic connection process, this part of the braking electric energy may also appear the phenomenon that the power flow is reversed and sent to the photovoltaic side

On the other hand, the output of the photovoltaic power generation system is significantly affected by the external weather, and the double intermittent and fluctuation of photovoltaic and traction loads will cause the photovoltaic power generation system to There is a phenomenon of excess photovoltaic power output, and there is currently no relevant policy to support photovoltaic power generation systems to send power back to the power system through traction substations

[0004] In the prior art, although there is a photovoltaic power generation system that uses back-to-back structure converters to directly connect to the electrified railway traction power supply system, and at the same time uses the energy storage device as a transfer station to stabilize the output power of the photovoltaic system, no similar control method has been seen yet. A technical solution that can be used to recover the regenerative braking electric energy of locomotives at the same time; although there is a scheme that uses the energy storage device alone to recover the braking electric energy of locomotives, there is no technical solution that is integrated with the photovoltaic power generation system

In the existing technology, it is impossible to maintain the safe and stable operation of the system while stabilizing the dual intermittency and volatility of photovoltaic and traction loads, and it is impossible to effectively recover the braking energy of the locomotive and the photovoltaic power that cannot be absorbed, and the energy utilization rate is extremely low

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