Alternating-current and direct-current power distribution network system load flow computing method based on droop control

Abstract

The invention provides an alternating-current and direct-current power distribution network system load flow computing method based on droop control. The method includes the following steps that firstly, initialization computing of a sagging curve is carried out; secondly, direct-current power of a direct-current power distribution system is updated through the Newton algorithm; thirdly, according to the updated direct-current power, a middle node voltage equation of an alternating-current power distribution system is solved, and droop characteristics are led into the alternating-current power distribution system; fourthly, whether alternating-current power flow and direct-current power flow converge or not is judged, if no, the second step continues for iterative computation till the alternating-current power flow and the direct-current power flow converge at the same time, and meanwhile a result is output. The invention provides the power flow mixing computing method suitable for a multi-terminal interconnection alternating-current and direct-current power distribution system adopting droop control, the gauss algorithm is adopted in the alternating-current power distribution system, and the Newton algorithm is adopted in the direct-current power distribution system. Meanwhile, the advantage that the gauss algorithm is little in calculation quantity and the advantage that the Newton algorithm is good in convergence are both taken into consideration, the problem that power flow does not converge is avoided, and the practicality level of power flow computing is improved.

Description

technical field [0001] The invention relates to a method for calculating the power flow of a distribution network system, in particular to a method for calculating the power flow of an AC / DC distribution network system based on droop control, and belongs to the technical field of power distribution system power flow calculation. Background technique [0002] With the rapid development of my country's economy, the traditional AC distribution network has encountered many development bottlenecks due to the increasing high-density load. The AC distribution network will face a series of power quality problems such as large line losses, tight power supply corridors, instantaneous voltage drops, voltage fluctuations, grid harmonics, and three-phase imbalances. Relevant studies have shown that DC distribution network has better performance than AC distribution network in terms of transmission capacity, controllability and improvement of power supply quality. The use of DC power dis...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the deficiencies of the prior art, the present invention proposes a droop control-based AC / DC distribution network system power flow calculation method, which can effectively improve the power flow calculation by avoiding the problem that the power flow solution deviates greatly from the droop curve, resulting in non-convergence of the power flow. The actual power grid and the practical level of the future large power grid

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