A fault current controller and control method for DC distribution network

Abstract

The invention relates to a fault current controller of a DC power distribution network. The fault current controller comprises a filtering loop, a series converter loop and a parallel converter loop,wherein the filtering loop comprises an LCL filter, the series converter loop comprises a full-bridge circuit, and the parallel converter loop comprises a DC / DC circuit. Under a steady-state condition, the fault current controller can be used for compensating temporary rising and temporary reduction of a voltage of a circuit and pulse; and under a fault condition, the fault current controller canbe used for providing current-limiting inductance and a reverse voltage, voltage adjustment of the DC power distribution network is comprehensively achieved, various functions of fault current limiting and blocking is achieved, and the application efficiency of the fault current controller is improved.

Description

technical field [0001] The invention relates to a fault current controller and a control method of a direct current distribution network, belonging to the technical field of direct current distribution networks. Background technique [0002] Compared with the AC distribution network, the DC distribution network has better performance in terms of transmission capacity, controllability, and power supply quality improvement. It can effectively improve the power supply capacity and power quality, and quickly and independently control active and reactive power. Power, reduce the use of power electronic converters, reduce power loss and operating costs, coordinate the contradiction between large power grids and distributed power, give full play to the value and benefits of distributed energy, and also help enterprises to adopt more energy-saving technology to improve energy efficiency. Therefore, the DC distribution network with reliability, safety, stability and economy has huge...

AI Technical Summary

Problems solved by technology

Therefore, power flow control, voltage compensation and fault current limitation in DC distribution network are important technical issues that must be faced and solved in its future development. Patent CN 201510179145.7 gives the DC power flow controller topology, and patent CN201610638360.3 gives the DC Current limiting device topology, the patent CN201710258530.X provides a DC fault blocking topology, but none of them involve the function reuse of DC equipment

Among the key technologies that need to be solved in the DC distribution network, power flow control and voltage compensation require long-term regulation, and the corresponding key equipment needs to be connected to the power grid for a long time, while the "number of short-circuit faults" and "duration" in the DC power grid Compared with its normal operation time, its ratio is very low. At the same time, the DC power grid has a high limit on the rate of rise of the fault current, which makes the cost of the current limiting device relatively high, which creates contradictions with its low operating frequency, low utilization rate, and long-term idleness.

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