DC transformer series side bus capacitor voltage-sharing device and voltage-sharing method

Abstract

The invention relates to a DC transformer series side bus capacitor voltage-sharing device and voltage-sharing method. The voltage-sharing device comprises a switching power supply, a control board card and a fan. The switching power supply acquires electric energy from the bus capacitor and supplies power to the control board card and the fan. Before the direct-current transformer is started, thecontrol board card collects the voltage of the bus capacitor, and when the voltage of the bus capacitor is smaller than the rated voltage, the rotating speed of the fan is controlled to decrease. When the voltage of the bus capacitor is higher than the rated voltage, the rotating speed of the fan is controlled to increase, and the fan is a heat dissipation fan of the direct-current transformer power module. According to the invention, the heat dissipation fan when the DC transformer power module operates normally is reused for static voltage sharing of the bus capacitor on the series side ofthe direct-current transformer, the efficiency of the whole direct-current transformer is improved, electrical elements of a power module of the direct-current transformer are reduced, the cost is reduced, the power density of the direct-current transformer is improved, and the control method is simple, effective and easy to implement.

Description

technical field [0001] The invention relates to the technical field of direct current distribution networks, in particular to a voltage equalization device and a voltage equalization method for bus capacitors on the series side of a direct current transformer. Background technique [0002] With the development of DC distribution technology, the demonstration and demonstration systems related to DC distribution network are gradually increasing. As an important DC equipment, DC transformer has been widely used in actual DC distribution network projects. The DC transformer that realizes the power transmission of the medium-voltage DC grid and the low-voltage DC grid, due to the limitation of the voltage of the power device, the device usually adopts the topology of the medium-voltage side in series and the low-voltage side in parallel (that is, the ISOP topology). [0003] For the DC transformer of ISOP topology, the control board of the power module usually uses switching powe...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a voltage equalizing device and method for bus capacitors on the series side of a DC transformer, which stabilizes the voltage of the DC bus by controlling the speed of the fan, and is used to solve the problem of the DC bus passing through the voltage equalizing resistor and the bus capacitor in the prior art. In parallel, the resistors continue to consume power and the resistors heat up

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