Flexible DC power distribution network fault positioning scheme applied to distribution network terminal

Abstract

The invention discloses a flexible DC power distribution network fault positioning scheme applied to a distribution network terminal, and the scheme comprises the steps: calculating the fault break variables of two ends of a monitoring point in a short time window after a fault; calculating a fault signal slope; identifying internal and external faults; obtaining the moment when a fault wave arrives at a monitoring point through empirical mode decomposition; and completing fault distance measurement. Current at two ends of a monitoring point is acquired through a distribution network terminal, current abrupt change in a short time window is calculated, fault abrupt change signals are extracted through a low-pass filter, current abrupt change slope is calculated, after the internal fault is determined, the fault signal is subjected to empirical mode decomposition to calculate the moment when the signal arrives at the monitoring point, and finally fault distance measurement is completed according to the arrival time, so that the problems of high protection configuration requirement, complex network, and large matching difficulty of system control, fault identification and protection of the flexible direct current power distribution network ring topology structure which is widely applied at present are solved.

Description

technical field [0001] The invention relates to the technical field of distribution networks, in particular to a flexible DC distribution network fault location scheme applied to distribution network terminals. Background technique [0002] With the continuous development of distributed power sources such as photovoltaics and wind power, the penetration rate of DC loads such as electric vehicles, household appliances, and smart buildings continues to increase, the gradual promotion of power storage, and the influence of important and sensitive loads on the demand for high-quality power supply, etc. Flexible DC distribution network is more suitable for the development of modern urban distribution network. The current flexible DC technology is facing many challenges. As the most critical part of the power transmission and distribution process, the immaturity of its protection technology has greatly restricted the development of flexible DC distribution networks. [0003] At p...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a flexible DC distribution network fault location scheme applied to distribution network terminals, which has the advantages of fault location and solves the protection configuration requirements of the currently widely used flexible DC distribution network ring topology High, its network is more complex, system control, fault identification and protection cooperation are more difficult, especially in the condition of a large number of distributed power access protection technology is more difficult to achieve, due to the fault characteristics of the DC system, its fault current will quickly rise, which is extremely harmful to the devices in the line, so there are extremely high requirements for fault location and removal speed

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