Offshore wind power alternating current grid-connected system design method and device

Abstract

The invention discloses an offshore wind power alternating current grid-connected system design method and device. A power grid side impedance mathematical model and a power supply side impedance mathematical model of an offshore wind power alternating current grid-connected system are obtained through determining a small signal sequence impedance equivalent model of the offshore wind power alternating current grid-connected system; then, a Bode diagram of the power grid side impedance and the power supply side impedance is drawn to obtain the phase margin of the system, if the phase margin does not reach a threshold value, preset parameters influencing the phase margin of the offshore wind power alternating current grid-connected system are adjusted, so that the phase margin of the offshore wind power alternating current grid-connected system reaches the threshold value. A rigorous theoretical basis is provided, the system parameters can be accurately adjusted, design redundancy and waste are avoided, the risk of super-synchronous oscillation can be thoroughly eliminated, and it is ensured that super-synchronous oscillation does not occur, so that the oscillation risk caused by super-synchronous oscillation of the offshore wind power alternating-current grid-connected system is reduced, and the operation reliability of the offshore wind power alternating-current grid-connected system is improved.

Description

technical field [0001] The invention relates to the technical field of offshore wind power, in particular to a design method and device for an AC grid-connected system of offshore wind power. Background technique [0002] Offshore wind power grid-connected system is a unit or station that converts offshore wind energy into electrical energy through blades, mechanical transmission equipment generators, converters and other equipment, and can generate electricity through AC or DC transmission. A system for delivering electrical energy to the onshore grid. [0003] The supersynchronous oscillation that occurs in the offshore wind power AC grid-connected system is a kind of broadband oscillation, and the oscillation frequency ranges from the power frequency to twice the power frequency, that is, 50 Hz to 100 Hz. Due to the influence of the phase-locked loop of the unit converter, the impedance characteristics of the offshore wind turbine appear as a capacitor with negative damp...

AI Technical Summary

Problems solved by technology

At present, there is no system design method that has a theoretical basis to effectively prevent the phenomenon of supersynchronous oscillation in the offshore wind power AC grid-connected system, and cannot reduce the risk of oscillation caused by the supersynchronous oscillation of offshore wind power.

Images