Rail transport traction system and energy feedback system thereof

Abstract

The invention discloses a rail transport traction system and an energy feedback system thereof, the energy feedback system comprising: N energy feedback modules, wherein a negative end of each energyfeedback module is connected to a negative end of a DC bus, a positive end of each energy feedback module is connected to a positive end of the DC bus, and each energy feedback module comprises M serially-connected DCDC modules and M energy storage units connected to the corresponding the M serially-connected DCDC modules; and a control unit, wherein by controlling the DCDC module, the control unit causes the M energy storage units to absorb energy of the DC bus or to release the energy to the DC bus, so that a voltage of the DC bus is within a preset voltage range. The system is formed by using multiple energy feedback modules connected in parallel, wherein each energy feedback module is formed by a plurality of serially-connected DCDC modules, thereby effectively reducing the withstand voltage level of a single DCDC module and the power level of each energy feedback module, at the same time, improving the flexibility of the system for power requirements.

Description

technical field [0001] The invention relates to the technical field of rail transit, in particular to an energy feedback system of a rail transit traction system and a rail transit traction system. Background technique [0002] At present, the rail transit system mainly adopts the DC traction power supply method, generally through the 12-pulse or 24-pulse uncontrolled rectifier, the AC power of the grid is rectified into DC power with a voltage level of 750V and 1500V, and the power is supplied to the train. [0003] Due to the one-way flow characteristic of the current of the uncontrolled rectifier, a large amount of energy generated by the train during braking cannot be fed back to the grid, resulting in an increase in the DC bus voltage in the rail traction system. In order to maintain the stability of the DC bus voltage, it is necessary to absorb the energy generated when the train brakes. For the energy generated during train braking, there are currently various techni...

AI Technical Summary

Problems solved by technology

In order to ensure the safety of energy recovery, it is necessary to ensure that the devices in a single DCDC module can meet the withstand voltage level above 750V / 1500V, but this will lead to a substantial increase in the size and cost of the system, and because the power of a single DCDC module is fixed, If the power is too small, it will not be able to meet the high-power traction requirements; if the power is too high, when applied to a low-power rail traction system, the system may not be able to operate at the optimal power point, so it cannot be well suited for In rail transit systems of different power levels

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