Composite low-voltage ride-through control device and control method for wind power generating set

Abstract

A composite low-voltage ride-through control device and control method for a wind power generating set, belonging to the technical field of low-voltage control of wind power generators. It is characterized by the combination of series and parallel compensation. When a low-voltage fault occurs in the power grid, it can realize full-phase compensation for the voltage at the fan port, and store the power that the fan has no time to output to the energy storage element through the series part. Normal and fault The state can compensate the reactive power and harmonics of the system in real time. The device is especially suitable for the units that have been put into operation, and does not need to make any changes to the structure and control of the existing units. The effect and benefit of the present invention is that the fan can be operated normally without being affected by the fault during the grid fault through voltage full-phase compensation, thereby ensuring that the fan will not be disconnected from the grid due to self-protection during the fault, and greatly reducing the impact of electromagnetic oscillation during the fault. Adverse effects and damage to fans. During a fault, it acts as a reactive power source to the grid, which contributes to the rapid recovery of the grid voltage.

Description

technical field [0001] The invention belongs to the field of renewable energy, relates to low-voltage ride-through control technology for wind power generators, and in particular to a composite low-voltage ride-through control device and control method for wind power generators. Background technique [0002] With the rapid increase of wind power, the proportion of wind power in the power system is increasing, and the problems caused by the integration of wind power into the grid have also attracted more and more attention. Low voltage ride through is the most prominent and urgent problem to be solved when wind turbines are connected to the grid. When the system voltage drops due to faults and other reasons, it will bring a series of transient processes to the wind turbine, such as overvoltage, overcurrent, or increase in the speed of the wind turbine, which poses a serious threat to the safety of the wind turbine and its control system. Therefore, under normal circumstances...

AI Technical Summary

Problems solved by technology

The advantage of using CROWBAR is that it can ensure the safety of the excitation frequency converter and accelerate the attenuation of the fault current. The disadvantage is that the DFIG rotor winding will be short-circuited during the operation of the CROWBAR, making DFIG a grid-connected cage-type asynchronous generator, which needs to absorb a large amount of power from the grid. Work power for excitation, which will be very unfavorable for the rapid recovery of power grid faults

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