Direct-driven wind power subsynchronous oscillation inhibition method based on network side control loop optimization

Abstract

The invention relates to a direct-driven wind power subsynchronous oscillation inhibition method based on network side control loop optimization. The method comprises steps that step 1, in a direct-driven blower fan network side control loop, a component igd of an inverter control loop current at a d axis and a correction igd' of an expression described in specifications are acquired through measurement; step 2, the correction current igd' of the control loop is filtered to acquire a subsynchronous component igdsub of the current igd'; step 3, according to time delay caused by filtering, a voltage signal Usub fed back to a voltage outer ring is acquired after phase compensation; and step 4, a PI controller is established, the voltage signal Usub fed back to the voltage outer ring, a DC capacitor voltage Udc and a DC reference voltage Uref are all taken as input variables of the outer ring PI controller, and subsynchronous oscillation inhibition is carried out. The method is advantaged in that extra equipment and complex control links are not needed, oscillation of each subsynchronous frequency band can be inhibited, and the method has a wide application scope.

Description

technical field [0001] The invention belongs to the field of power systems, and relates to wind power grid-connected operation and control technology, in particular to a direct-drive wind power subsynchronous oscillation suppression method based on grid-side control loop optimization. Background technique [0002] At present, the large-scale centralized grid-connected transmission of wind power has become the most extensive form of wind power transmission, and the direct-drive wind turbine has gradually become one of the mainstream models due to its advantages of simple structure, high efficiency and high reliability. [0003] However, there is a large risk of subsynchronous oscillation in the cluster wind power series supplementary transmission system. Therefore, when the direct-drive wind turbine interacts with the weak AC grid, power oscillations in the subsynchronous frequency range (2-50Hz) may occur in the system from time to time, and the subsynchronous Synchronous os...

AI Technical Summary

Problems solved by technology

Therefore, the traditional suppression measures based on extracting and utilizing the subsynchronous component in the speed signal are not suitable for the suppression of direct drive wind power subsynchronous oscillation.

The internal mechanism of the subsynchronous oscillation of the direct drive fan is not very clear, and the frequency range of the subsynchronous oscillation is also difficult to predict

The current subsynchronous oscillation suppression measures generally control the SVG or SVC to generate a current that suppresses the subsynchronous oscillation and inject it into the system to eliminate the subsynchronous oscillation, but these suppression measures generally require expensive equipment and complicated control processes. There are also problems such as mismatched control strategies, slow response and insignificant effects, which make it difficult to fundamentally solve the subsynchronous oscillation of direct-drive wind power.

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