Fault ride-through control method and system for flexible direct current sending-out system of new energy island

Abstract

The invention discloses a fault ride-through control method and system for a flexible direct current sending-out system of a new energy island. The method comprises the following steps: when a flexible direct current power grid is faulty: a flexible direct current convertor station sends a control signal to energy storage equipment according to a detected fault type, and the energy storage equipment performs power control according to the control signal; when the fault of the flexible direct current power grid is cleared away: the flexible direct current convertor station sends an active control signal to a new energy power station according to a recovery condition of the flexible direct current power grid; the new energy power station controls generator tripping of a wind turbine generator according to the active control signal; the energy storage equipment controls sent active power according to an output of the faulty new energy power station and the conveying capacity of the flexible direct current power grid, so as to complete fault ride-through. The fault ride-through control method disclosed by the invention realizes quick control over the power; after the fault is restored,protection is turned on to cut off surplus wind power according to a refinement control requirement, so as to complete the ride-through.

Description

technical field [0001] The present invention relates to the technical field of new energy fault ride-through control for isolated island transmission, in particular to a fault ride-through control method and system for a new energy island flexible direct transmission system. Background technique [0002] The traditional long-distance transmission of large-scale wind power, regardless of the traditional LCC type DC or AC, requires strong synchronous power support at the sending end, and sometimes even needs to provide support at the receiving end. And with the transformation of the national energy strategy, the difficulty lies in the development of wind power and the development of traditional synchronous power. For millisecond-level control wind turbines, it is difficult to respond to relevant control requirements in a timely manner when the island is connected to the flexible DC grid. Especially after the DC grid fails and some DC lines are cut off, it is necessary to quick...

AI Technical Summary

Problems solved by technology

For millisecond-level control wind turbines, it is difficult to respond to relevant control requirements in a timely manner when the island is connected to the flexible DC grid. Especially after the DC grid fails and some DC lines are cut off, it is necessary to quickly limit the wind power injected into the flexible DC system. The existing wind turbines Both power control and protection cut-off schemes are difficult to meet the requirements of 6-8ms power reduction control

In addition, installing energy-consuming devices on the AC-side busbars of the flexible HVDC converter station to control the active power injected into the converter station will cause the loss of wind power during faults and affect wind power consumption.

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