A dynamic model of electric power network and its construction method

Abstract

The invention discloses a power grid dynamic model and a construction method thereof. The model comprises a simulated generator set, a simulated transmission line, a simulated transformer bank, a simulated load and a forced zero sequence current distributor, wherein the simulated transmission line simulates distribution parameters of an original transmission line by adopting an equivalent chain circuit and piecewise concentrated parameters, the forced zero sequence current distributor is connected in series to the simulated transmission line and comprises a core unit and four phases of transmission lines, and the four phases of transmission lines are wound on the core unit and have equal wound number and same wound direction; and the forced zero sequence current distributor is used for enabling a zero sequence current value synthesized by three phases of current A, B and C to be equal to that measured on the N phase but opposite in direction. The constructed model can comprehensively and truly reflect various operating conditions of the original transmission line, and well solves the problems in complex power grid dynamic simulation experiments.

Description

technical field [0001] The invention belongs to the field of power system test research, and more specifically relates to a dynamic model of a power network and a construction method thereof. Background technique [0002] The power system is a complex dynamic system. When the power system fails, the system changes from one state to another, accompanied by a complex electromagnetic transient process. However, in the research of dynamic simulation experiments, when the power system has asymmetric loads and faults, the zero-sequence current value of the A, B, and C three-phase current measured on the single circuit line is different from the zero-sequence current value measured on the N-phase. Again, such a model cannot truly reflect the dynamics of the prototype system. [0003] Some scholars studied the development of the small current grounding system experimental platform and the development of experimental content, and introduced the wiring and equipment selection of the ...

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Problems solved by technology

[0004] Aiming at the above defects or improvement needs of the prior art, the present invention provides a power network dynamic model and its construction method, thus solving the problem of zero-sequence current caused by the use of N-phase transmission lines to simulate the ground network of the prototype power system in the existing power network dynamic model The technical problem that the value is not equal to the zero-sequence current value synthesized by the A, B, and C three-phase currents

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