Independent series-parallel-connection modular subway regenerative braking super-capacitor energy storage device

Abstract

The invention relates to a modular subway regenerative braking super-capacitor energy storage device comprising a direct-current touch net, super-capacitor group modules and DC 750-V bidirectional DC/DC modules. The super-capacitor energy storage device is characterized in that one group of super-capacitor group modules and one group of DC 750-V bidirectional DC/DC modules are connected to form one group of regenerative braking modules. Two groups of regenerative braking modules including a first regenerative braking module and a second regenerative braking module are connected in series to the two ends of the direct-current touch net; the first regenerative braking module is connected in parallel with at least one group of regenerative braking modules; and the second regenerative braking module is connected in parallel with at least one group of regenerative braking modules. Because of the plurality of super-capacitor groups connected with each bidirectional DC/DC module independently, the direct series-parallel-connection number of the single super capacitor body is reduced; and on the basis of series connection of the direct-current-side two groups of modules of the DC 750-V bidirectional DC/DC modules, DC 1500-V application is realized and different current requirements are met by direct-current-side parallel connection of multiple groups of DC 750-V bidirectional DC/DC modules. Moreover, the modular subway regenerative braking super-capacitor energy storage device has advantages of high reliability, complete modular design, high efficiency, small size, and flexible meeting of different power needs.

Description

technical field [0001] The invention relates to the technical field of urban rail transit power supply systems, in particular to a modular subway regenerative braking supercapacitor energy storage device. Background technique [0002] In recent years, my country's urban rail transit has developed very rapidly. The existing subway traction power supply method uses a diode rectifier unit to rectify 35 / 33kV medium-voltage AC power into 1500V DC, and supplies power to the traction motor on the subway train through the DC catenary. However, this power supply method can only realize the one-way power flow of electric energy from the grid to the motor, and the motor works in the generator state during the braking process, and the mechanical energy of the train is converted into electric energy. In order to ensure that the DC catenary voltage is within the safe range, the electric energy generated by train braking is basically absorbed by the resistance power consumption method, whi...

AI Technical Summary

Problems solved by technology

However, its supercapacitors are only grouped in series and not grouped in parallel. A large number of monomers need to be directly connected in parallel, and there is a reliability risk caused by uneven shunting between monomers.

Moreover, the bidirectional DC / DC module of this solution does not integrate DC filter inductors and high frequency filter capacitors, and its parameters cannot well match the number of parallel connections of different bidirectional DC / DC modules, which affects the ripple filtering effect

[0006] Existing technical scheme two: In 2010, Feng Jingjing's master's degree thesis of Nanjing University of Aeronautics and Astronautics "Research on Regenerative Braking Energy Absorption and Utilization Technology Based on Supercapacitors", adopted a modularization of four converter modules connected in series on the high voltage side and independently combined on the supercapacitor side Structure, module voltage equalization control is complex

Moreover, this scheme does not consider the problem of parallel expansion of converter modules and super capacitors

[0007] To sum up, none of the existing technical solutions considers the current-sharing consistency problem caused by the parallel connection of a large number of supercapacitors, and there are hidden dangers in reliability.

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