HVDC dynamic phasor calculation method and system combined with phase-locked loop

Abstract

The invention relates to an HVDC dynamic phasor calculation method and system combined with a phase-locked loop. A direct current system dynamic phasor model suitable for asymmetric faults is established by analyzing and modeling an HVDC whole system including a phase-locked loop, a converter, a direct current line and a control system, and rapid and accurate calculation of high-voltage direct current transmission transient response is achieved. Compared with a traditional dynamic phasor calculation method, the calculation method is low in time consumption and high in precision, the commutation failure working condition can be solved, closed-loop calculation of the HVDC system is achieved, that is, other electrical quantities such as direct-current voltage, direct-current current, controlled quantity and alternating-current current can be calculated only by inputting three-phase alternating-current voltage, and the model has engineering practical value.

Description

technical field [0001] The invention relates to the field of high-voltage direct current transmission, in particular to an HVDC dynamic phasor calculation method and system combined with a phase-locked loop. Background technique [0002] The characteristics of the reverse distribution of energy resources and power load in my country have enabled the rapid development of high voltage direct current (HVDC) with large capacity and long-distance transmission capabilities. With the continuous increase of DC lines in the system, the AC-DC hybrid system puts forward new requirements for the stable operation and relay protection of the power grid system. Therefore, building a new system model and proposing corresponding calculation methods to accurately and quickly solve the transient response of the HVDC system under various faults has become a hot issue in related fields. [0003] At present, relevant scholars mainly propose four models for HVDC systems: quasi-steady state model,...

AI Technical Summary

Problems solved by technology

The state space model uses algebraic differential equations to describe the working conditions of the converter topology, but there are few related studies and this method needs to model all possible topological situations, so the algorithm complexity is high

Although there is some research on the dynamic phasor model at present, most of them only stay at the theoretical stage due to the lack of modeling of phase-locked loops, DC lines, control systems, etc.

Moreover, the existing dynamic phasor studies all use frequency-domain convolution calculations with high complexity, which offsets the advantages of the rapidity of the dynamic phasor model to a certain extent.

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