A Control Method of Multi-circuit DC Additional Frequency Limiting Controller

Abstract

An embodiment of the invention discloses a control method of a multi-circuit direct current additional frequency limit controller, and applicable to a multi-circuit direct current system with an asynchronous networking sending end. The control method comprises the steps of pre-setting a regulation and control initial frequency threshold value <delta>f<on> and a regulation and control ending frequency threshold value <delta>f<off>, calculating frequency deviation <delta>f, and determining whether the frequency deviation <delta>f is greater than the regulation and control initial frequency threshold value <delta>f<on> or not; and if so, reasonably setting conveying power of each-circuit direct current based on a "stepped type" control strategy specific to the multi-circuit direct current of the synchronous networking. The embodiment of the invention discloses the control method of the multi-circuit direct current additional frequency limit controller; the multi-circuit direct current additional frequency limit controller is reasonably set based on the "stepped type" control strategy; sequential regulation and control in the frequency rising process can be performed in different stages and steps; and the over-regulation problem caused by synchronous and orderless regulation and control actions of each direct current in FLC (frequency limit control) in the power grid fault condition is avoided, so that controllability on the direct current regulation and control is ensured.

Description

Technical field [0001] The invention relates to the technical field of power system stability control, in particular to a control method of a multi-circuit DC additional frequency limit controller. Background technique [0002] The HVDC system has the advantages of large capacity and long-distance power transmission. At present, my country’s "West-to-East Power Transmission" project has adopted a parallel transmission method of HVDC and AC systems. In the AC and DC parallel mode, the AC and DC systems in the grid will have mutual influence, that is, if the DC system fails, the AC system will also be affected. In order to avoid grid accidents caused by the mutual influence of AC and DC systems due to DC faults, two or more power grids can be connected asynchronously. For example, my country will realize asynchronous networking between Yunnan Power Grid and Southern Power Grid. [0003] In the asynchronous grid connection mode, if a DC blocking failure occurs, the frequency stabilit...

AI Technical Summary

Problems solved by technology

[0006] In the embodiment of the present invention, a multi-circuit DC additional frequency limit controller control method is provided to solve the problem of system current over-regulation caused by the "swarming" control action of each DC FLC in the prior art

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