Power system short circuit current attenuation calculating method based on coordinate transformation

Abstract

The invention relates to a power system short circuit current attenuation calculating method based on coordinate transformation. The method includes the following steps 1) acquiring an initial node voltage equation, and correcting the initial node voltage equation to obtain the corrected node voltage equation; 2) performing the real-number expression on the corrected node voltage equation; 3) obtaining the network equation of a rotary motor by the coordinate transformation according to the real-numbered node voltage equation, and respectively obtaining the equivalent injection current equation of a generator and the corresponding node of the motor according to the network equation of the rotary motor; 4) respectively obtaining the attenuation potentials of the generator and the motor according to the potentials of the generator and motor before the short circuit and the calculation equation of the rotary motor stator current; 5) calculating the short-circuit voltage of each node according to the attenuation potentials of the generator and the motor; and 6) acquiring the short circuit current of the short circuit nodes. Compared with the prior art, the power system short circuit current attenuation calculating method has the advantages of comprehensive consideration, accurate calculation, and closeness to reality.

Description

technical field [0001] The invention relates to a method for obtaining short-circuit current, in particular to a method for calculating the attenuation of short-circuit current in a power system based on coordinate transformation. Background technique [0002] At present, the conventional short-circuit current calculation adopted by domestic electric power enterprises only calculates the periodic component of short-circuit current, but cannot calculate the attenuation of the short-circuit current periodic component. Although the traditional short-circuit current calculation curve method can calculate the attenuation of the short-circuit current periodic component, but In this method, the load is equivalent to a static load, and the typical operation mode of the power system specified in advance is used instead of the actual operation state. [0003] When the commercial power system simulation software commonly used by power grid enterprises calculates the short-circuit curre...

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Problems solved by technology

[0002] At present, the conventional short-circuit current calculation adopted by domestic electric power enterprises only calculates the periodic component of short-circuit current, but cannot calculate the attenuation of the short-circuit current periodic component. Although the traditional short-circuit current calculation curve method can calculate the attenuation of the short-circuit current periodic component, but In this method, the load is equivalent to a static load, and the typical operation mode of the power system specified in advance is used instead of the actual operation state

[0003] When the commercial power system simulation software commonly used by power grid enterprises calculates the short-circuit current, PSASP ignores the influence of the load; the BPA program can consider the comprehensive load including the induction motor, but can only calculate the initial effective value of the periodic component; although the BKDY module of PSS / E can calculate The attenuation of the periodic component of the short-circuit current, but this method equates the load to a static load. The transient stability calculation function of the above-mentioned simulation software can calculate the attenuation of the periodic component by solving the differential equation of the entire system. However, the data preparation is cumbersome and the amount of calculation Too large, generally not used for engineering calculation of short-circuit current

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