Protection method of DC regional power distribution network for medium voltage DC power supply

Abstract

The invention belongs to the field of marine electric power system protection, and particularly relates to a method for protecting medium-voltage direct-current power supply direct current zone distribution networks. The method solves the problem that selective protection can not be achieved through an existing protection method. According to the method, the selection protection on an annular direct current is achieved through coordinated protection of DC / AC / DC power transformation modules and direct current breakers, the short-circuit fault is accurately and rapidly removed, and meanwhile the cost pressure, such as the economy cost pressure, the size cost pressure and the weight cost pressure, caused by universal use of the direct current breakers on buses is avoided. The selective protection of low-voltage alternating-current distribution networks and low-voltage direct-current distribution networks is achieved through the coordinated protection of the transformation modules and inferior breakers, faults are limited inside a zone, the superior direct current buses are not influenced, and the power supply continuity of a marine electric power system to daily loads is remarkably improved.

Description

technical field [0001] The invention belongs to the field of ship power systems, and in particular relates to a DC regional power distribution network protection method for medium-voltage direct current power supply, which is suitable for the selective protection of a DC regional power distribution network using a 700V class DC bus. Background technique [0002] The integrated power system uses the idea of ​​power integration to realize the unified dispatch of electric energy, mainly including six modules of power generation, power distribution, power transformation, propulsion, energy storage, and monitoring / management, which is the development direction of the future ship power system. Due to its advantages in power density, volume weight, electromagnetic compatibility, vibration and noise, medium voltage DC will gradually replace medium voltage AC as the standard form of power generation modules. [0003] As for the power distribution module, its main task is to transmit ...

AI Technical Summary

Problems solved by technology

[0006] For the protection of the low-voltage AC network and the low-voltage DC network, the traditional power distribution network is generally powered by a generator, and the circuit breaker is set according to the time-current principle to achieve coordinated protection. The working characteristics of the device are essentially different from those of the generator. Considering the cost, volume, weight and other factors of the device, under the limited design margin, its output overcurrent capability is only 2 to 3 times the rated current, which may not be able to provide for the lower circuit breaker. Sufficient short-circuit current to cut off the short circuit, resulting in the loss of power to the entire network

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