Large power modularized DC power supply apparatus and control method thereof

Abstract

The invention relates to a large-power modularized DC power supply device and a control method thereof. The large-power modularized DC power supply device is composed of three two-way power units and a transformer with zigzag connection. Each two-way power unit includes twelve reverse-conducting IGBTs forming six bridge arms, wherein each bridge arm is connected with primary windings Tx1, Tx2 and Tx3 of the transformer with zigzag connection. A voltage and current sensor is also connected. The AC-side voltage of the two-way power unit is superposed with the phases of fifteen secondary windings in zigzag connection; a filter capacitor is connected between every two phases to generate three-phase symmetrical 18 ladder wave AC line voltages; and the DC sides of the two-way power units are connected with each other in parallel. The power supply device and the control method thereof have the advantages of stable DC output voltage, fast system response, good controllability, and less harmonic wave pollution at the AC sides, and particularly can achieve energy feedback from the DC side to the AC side and two-way energy transmission between the DC side and the AC side, thereby achieving positive effect on energy saving and emission reduction.

Description

technical field [0001] The invention relates to the field of direct current power supply, in particular to a high-power modular direct current power supply device and a control method thereof. Background technique [0002] The field of DC power supply is currently an important industry that is closely related to the national economy and the people's livelihood that the country is vigorously developing. DC power supply devices have important applications in urban rail transit, mine traction, port cranes and other fields, and have broad prospects. However, there are still many problems in the application of the current DC power supply device. The following takes the traction power supply system of urban rail transit as an example to illustrate. [0003] At present, urban rail transit mainly adopts two DC power supply systems of 750V and 1500V, and generally adopts 12-pulse or 24-pulse diode uncontrolled rectification. This power supply method has been used for decades, and h...

AI Technical Summary

Problems solved by technology

However, such devices generally have a small capacity, and the energy that can be stored is limited, which cannot fully meet the needs of energy feedback on the DC side of large-capacity DC power supply systems.

Moreover, the relevant devices are still unmanufacturable in China, and are expensive and costly; using the thyristor inverter device, the DC energy can be converted into AC energy through the inverter device and fed back to the AC side

However, due to the phase-controlled thyristor used in the existing device, when the DC side energy is fed back to the AC side, the harmonic content input from the device to the AC grid is very large, which affects the power supply quality of the AC grid, and there are also shortcomings in use.

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