Converter-based low voltage ride through control system of wind generating set

Abstract

The invention relates to a converter-based low voltage ride through control system of a wind generating set, comprising a converter, a converter controller and a low voltage ride through main controller, wherein the converter and an auxiliary circuit breaker are connected in series to form a controlled branch circuit; a main circuit breaker between the wind generating set and a grid is connected in parallel with the controlled branch circuit; a direct current positive electrode bus bar and a direct current negative electrode bus bar are arranged between a rectifier and an inverter; a capacitor and an unloading resistor are connected between the direct current positive electrode bus bar and the direct current negative electrode bus bar; the unloading resistor and the capacitor are connected in parallel; the unloading resistor and a controlled valve are connected in series; the controlled valve is connected with the converter controller; a grid end is connected to an alternating current voltage detector; a direct current voltage detector is connected between the direct current positive electrode bus bar and the direct current negative electrode bus bar; the alternating current voltage detector and the direct current voltage detector are both connected with the low voltage ride through main controller; and the low voltage ride through main controller is connected with the converter controller, the main circuit breaker and the auxiliary circuit breaker. The invention is effectively adapted to occasions where the depth voltage dips and has favorable stability.

Description

technical field [0001] The invention relates to a low-voltage ride-through control system of a wind power generating set. Background technique [0002] With the continuous increase of installed capacity of wind turbines, the operation of wind power systems in the event of grid failures has become particularly important. At the same time, grid guidelines require wind turbines not to operate off-grid within a certain range of instantaneous grid voltage drops. Because the voltage drop will bring a series of transient processes to the motor, such as overvoltage, overcurrent, or speed increase, etc., which will seriously endanger the safe operation of the fan itself and its control system. Therefore, in general, if the power grid fails, the fan When passive self-protection is implemented, it will be disconnected immediately, regardless of the duration and severity of the fault, so that the safety of the fan can be guaranteed to the greatest extent. It is acceptable when the grid...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the deficiencies of the existing low voltage ride-through control mode of the wind power generating set that cannot adapt to deep voltage dips and poor stability

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