Double-end DC power distribution network fault positioning method based on current adaptive control

Abstract

The invention discloses a double-end DC power distribution network fault positioning method based on current adaptive control, and the method is characterized in that the fault method comprises the following steps: S1, constructing a double-end flexible DC power distribution network model; S2, taking fault detection and countermeasures; S3, performing system sampling; S4, obtaining a calculation formula; and S5, calculating a final fault distance. According to the fault positioning method, transition resistance is eliminated through a double-end method, the high transition resistance interference resistance is achieved, fault current self-adaption control is adopted, the actual fault current at the control mode switching moment is extracted as the peak value of a reference signal, the zero crossing point of the reference signal is still unchanged, and the P I adjusting time can be greatly shortened. The current active control accuracy is improved, the error between different sampling points can be effectively reduced through molecular denominator unary linear regression analysis of traditional double-end method fault positioning, and the fault positioning precision is greatly improved.

Description

technical field [0001] The invention relates to a fault detection technology for a flexible direct current distribution network, in particular to a fault location method for a double-terminal direct current distribution network based on current self-adaptive control. Background technique [0002] In recent years, with the development of power electronics technology, the flexible DC distribution network can achieve independent control of active and reactive power, large power transmission capacity, and reduce distributed power generation such as photovoltaics and wind power due to its low line cost and low loss. The intermediate link of power supply and DC load access to the grid, further reducing access costs, improving power conversion efficiency, and improving power quality have become important development directions for future urban smart power distribution. [0003] At present, most of the flexible DC power distribution projects that have been built use cable lines with...

AI Technical Summary

Problems solved by technology

However, the effects of transition resistance, uneven distribution of line parameters and calculation errors of differential terms cannot be ignored

The double-ended method can eliminate the influence of the transition resistance on the ranging accuracy, and use the information of each sampling point to calculate the fault distance once, but the denominator term introduced by the double-ended method will appear zero-crossing, which brings numerical stability problems

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