Implementation method of novel software phase-locked loop used for signaling virtual channel (SVC) control system

Abstract

The invention discloses an implementation method of a novel software phase-locked loop used for a signaling virtual channel (SVC) control system. The implementation method of the novel software phase-locked loop used for the SVC control system utilizes a phase-locked principle based on an instantaneous reactive power theory, achieves a software phase-locked module by coding in a digital signal processer (DSP) unit, replaces a complex integration link by a field programmable gate array (FPGA) counter, produces a phase-locked angle theta, enables the software phase-locked module to match with a phase-locked counter and achieves a phase-locked function. Under the conditions of voltage unbalance, voltage dropping and frequency discontinuity, the implementation method of the novel software phase-locked loop used for the SVC control system is still capable of rapidly and reliably achieving phase locking. A software phase-locked loop module calculates a correction angle of each phase according to a system sample and a condition of calculating delay and unbalanced three-phase voltage. The SVC control system triggers the control on the basis of each phase correction angle, reduces trigger error of a thyristor and improves system control accuracy. The implementation method of the novel software phase-locked loop used for the SVC control system is easy to achieve, is capable of being conveniently connected with other modules in the SVC control system, is simple and enables parameters to be conveniently modified and possesses good generality and expandability.

Description

technical field [0001] The invention relates to a method for realizing a novel software phase-locked loop used in an SVC control system, and belongs to the technical field of power electronics. Background technique [0002] With the development of the national economy and the advancement of modern technology, the load of the power grid has increased sharply, and the requirements for the inductive reactive power of the power grid have also increased day by day, especially the impact load and non-linear load capacity such as reversible large-scale rolling mills and steel-making electric arc furnaces. Increase, coupled with the commonly used power electronics technology, causes voltage waveform distortion, voltage fluctuation flicker and three-phase unbalance to occur in the power grid, resulting in adverse effects such as reduced power quality, reduced power factor of the power grid, and increased network loss. Static reactive power compensation equipment (SVC) is generally co...

AI Technical Summary

Problems solved by technology

[0004] In terms of phase-locked loop methods, the traditional phase-locked methods include analog phase-locked loops relying on hardware, open-loop phase-locked loops relying on αβ coordinates calculated by software, and Fourier decomposition phase-locked loops. In order to suppress the influence of negative sequence voltage under unbalanced voltage conditions, the dq phase-locked loop generally uses the 100Hz component attenuation coefficient as the PI controller design index, so there is also the problem of slow response speed. shortcoming

Images