Multi-port grid-shaped modularized multi-level direct-current converter

Abstract

The invention provides a multi-port grid-shaped modularized multi-level direct-current converter. According to the multi-port grid-shaped modularized multi-level direct-current converter, the connection mode that completely same non-isolated DC-DC converter modules are connected in parallel at the same stage and the output ends of the DC-DC converters at different stages are sequentially connected in series is adopted, and Buck-Boost modules are selected as single DC-DC converter modules; the multi-port converter generally has a relatively strong coupling effect between ports, so that each DC-DC converter further comprises a control loop, so that multi-port decoupling control can be realized. The modules in the converter have identical circuit structures and electrical parameters, standardized production and assembly can be realized, and current sharing and voltage sharing among the modules can be realized. According to the multi-port grid-shaped modularized multi-level direct-current converter topological structure, on the basis of meeting port characteristic requirements and device voltage and current stress balanced distribution, the optimal design of minimum filling of the number of modules in a grid structure is achieved, and flexible expansion of the number of ports, the voltage level and the power capacity can be achieved.

Description

technical field [0001] The invention belongs to the field of power transmission and distribution of electric power systems, and in particular relates to a multi-port grid-shaped modular multi-level DC converter. Background technique [0002] New energy is a sustainable energy source. Distributed new energy power generation is a power generation method different from traditional energy. Although it can be discovered, it has obvious intermittency, and there are many voltage levels and large power fluctuations. It needs medium and low voltage direct current. The network effectively interconnects multiple power sources and loads to achieve optimal energy allocation. The multi-port DC / DC converter (Multiple Port DC / DC Converter, MPC) can quickly realize the power matching between the power supply and the load with different voltages and different internal resistances, effectively reducing the number of converters used in the power grid, and facilitating voltage and power The cen...

AI Technical Summary

Problems solved by technology

The disadvantage of the common bus type MPC is that the circuits are independent of each other, resulting in a large number of devices used, low utilization rate, and uneven stress distribution of switching devices; device multiplexing MPC still does not solve the uneven distribution of device voltage and current stress and the stress of some devices is too high The problem

In the switched capacitor MPC network, the capacitor voltages at all levels cannot be independently controlled, and the charging and discharging process between the capacitors is directly connected in parallel, which will generate large current spikes and device losses

[0004] Due to the limitation of device stress and topological structure, the non-isolated MPC in the existing technology cannot meet the rapid development needs of the number of ports, voltage level, and power capacity of medium and low voltage DC systems such as distributed new energy power generation to a certain extent, and cannot be formed. Efficient, flexible and expandable modular topology and control method

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