Short-circuit current calculation method for double-fed wind power generation system by considering different slips

Abstract

The invention discloses a short-circuit current calculation method for a double-fed wind power generation system by considering different slips. Double-fed wind power generators are divided into two types based on slips: a type with large slip and a type with small slip. The double-fed wind power generator in the type with large slip takes positive sequence equivalent impedance as a positive sequence equivalent model, and the double-fed wind power generator in the type with small slip adopts equivalent potential to be serially connected with positive sequence equivalent impedance to be taken as a positive sequence equivalent model; next, negative sequence equivalent impedance is taken as a negative sequence equivalent model of the double-fed wind power generator; and finally, by performing joint solving on the positive sequence equivalent impedance, the negative sequence equivalent impedance of the double-fed wind power generator and an equivalent circuit of an electric power system, the short-circuit current of the double-fed wind power generation system is worked out. By considering influence of different slips to short-circuit calculation sequence component models of the double-fed wind power generators, the short-circuit calculation models for the double-fed wind power generators of different slips are established, so that short-circuit current calculation accuracy of the double-fed wind power generation system is improved.

Description

technical field [0001] The invention relates to the field of short-circuit calculation of a power system after wind power is connected, and more particularly relates to a calculation method for short-circuit current of a doubly-fed wind power generation system considering different slips. Background technique [0002] Wind power is the main force of renewable energy power generation and is considered to be an effective alternative to traditional fossil energy power generation. In some regional power grids, its installed capacity has exceeded 10% of the total system power capacity. Doubly-fed wind turbines are the main equipment for wind power generation, accounting for more than 50% of wind power grid-connected capacity. The stator of the asynchronous motor of the double-fed wind turbine is directly connected to the grid, and the rotor winding is connected to the grid through a back-to-back converter. Under normal operating conditions, the rotor converter feeds the stator ...

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Problems solved by technology

Therefore, the short-circuit calculation model of the conventional asynchronous motor cannot accurately calculate the short-circuit current of the double-fed wind power generation system, which restricts the research in the fields of power system planning and design, relay protection setting calculation, etc.

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