Cooperative control system for grid following-grid constructing type converter hybrid system under asymmetric grid fault

Abstract

The invention provides a cooperative control system for a network following-network constructing type converter hybrid system under an asymmetric power grid fault, and relates to the technical field of cooperative control. The system comprises an upper collaborative distribution layer which is used for dynamically distributing a negative sequence support task according to a real-time fault working condition and a converter operation margin; the lower local execution layer is used for uniformly transforming the GFL and the GFM into a controllable negative sequence current source in a negative sequence control domain and executing an upper instruction; the upper collaborative distribution layer is based on a double-loop control structure, an outer loop calculates a total negative sequence current instruction required by the system, and an inner loop distributes the total negative sequence current instruction to a GFL and a GFM based on a dynamic distribution coefficient; and a GFL side control strategy and a GFM side control strategy are configured in the lower local execution layer. The effectiveness, robustness and wide applicability of the transient performance of the GFL-GFM parallel system under the asymmetric fault are improved.

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