DC side stability analysis method suitable for multi-terminal DC power transmission system

Abstract

The invention discloses a DC side stability analysis method suitable for a multi-terminal DC power transmission system, and the method comprises the steps: S1, building a mathematic model, including aDC side system equation and a control equation, of the multi-terminal DC power transmission system under the action of droop control; S2, linearizing a steady-state operation point of the multi-terminal DC power transmission system to obtain a linearized stability analysis model of the mathematical model, and obtaining a transfer function between a direct-current variable quantity and a direct-current voltage variable quantity after the multi-terminal DC power transmission system is disturbed; S3, deriving a DC stability criterion of the multi-terminal DC power transmission system based on the transfer function; S4, judging whether a droop parameter set under the current electrical parameter is in a stable range of the multi-terminal direct-current power transmission system or not based on a stability criterion; if the droop parameter exceeds the stable range, adjusting a controller parameter and / or changing an operation point of the DC power transmission system; otherwise, requiringno processing. The method achieves the quick discrimination of the stability of a DC power grid, and facilitates the design or adjustment of the parameters of the controller by a power system operator.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a DC side stability analysis method applicable to a multi-terminal DC transmission system. Background technique [0002] In recent years, with the development of multi-terminal DC transmission (multi-terminal, MTDC) systems, converters based on droop control have attracted extensive attention from scholars and power technicians at home and abroad. Droop control can conveniently realize the power distribution of the DC grid, and is expected to become the mainstream control strategy for multi-terminal DC system converters. But at the same time, the power fluctuation of the grid, the unreasonable design of the controller parameters, and the mutual coupling between the DC transmission network and the controller will bring a series of challenges to the stable operation of the DC grid. Analyzing and judging the stability of the DC power grid under droop control has become a ke...

AI Technical Summary

Problems solved by technology

[0003] The traditional input impedance method and eigenvalue analysis method can judge the stability of the system through numerical calculation, but its disadvantages are that it cannot give the analytical criteria for the stability of the DC power grid, and it is also difficult to analyze the impact of system parameters, control parameters and system operating conditions on the DC power grid. side stability

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