Continuous power flow method of alternating current and direct current power system considering wind power randomness

Abstract

The invention discloses a continuous power flow method of an alternating current and direct current power system considering wind power randomness. Specific to the problem existing in stability calculation of a static voltage of a wind power plant-containing alternating current and direct current hybrid power transmission system, a Monte carlo method is adopted creatively to obtain a function relation between wind power output and voltage collapse point load margin through fitting; a calculation formula of voltage collapse point load margin expectation is deduced according to an air speed weibull distribution function, a relation between wind power output and power and a fitted function; the effectiveness of the method is verified on an improved IEEE9 node system; compared with the conventional Monte carlo method, the continuous power flow method disclosed by the invention is higher in accuracy and higher in speed; influence to the voltage collapse point load margin expectation from a direct current variable control value and air speed probability distribution parameters k, c values is further analyzed; and the method also can perform analysis on load margin of different load output directions conveniently, so that a direct current control value can be reasonably set by an operator according to the current air speed distribution condition so as to regulate an operating way favorably.

Description

technical field [0001] The invention belongs to the field of safe and stable operation of power systems, and proposes a continuous power flow (CPF) calculation method for an AC / DC hybrid transmission system considering the randomness of wind power. Background technique [0002] With the continuous development of DC transmission technology, the interconnection of AC and DC grids will become the basic form of my country's grid framework. At the same time, with the continuous expansion of wind power scale, the random uncertainty of wind power has a greater impact on the static voltage stability of the power grid. The impact of HVDC transmission and wind power access on the static voltage of the power system has attracted extensive attention. [0003] The continuum power flow method can easily obtain the PV curve of the system, and the "nose point" of the PV curve is the collapse point of the system voltage, from which the power transmission capacity of the system can be obtain...

AI Technical Summary

Problems solved by technology

In the research on the static voltage stability of the AC-DC system with wind farms in the literature "Calculation of Available Transmission Capacity of Power Grid Including VSC_HVDC Grid-connected Offshore Wind Farms", the deterministic value of wind power is mainly processed without considering the impact of randomness

The literature "Regional Transmission Capacity Calculation of Large-Scale Wind Power Transmitted by DC" uses Monte Carlo method and clustering method to analyze the influence of randomness of wind power, but it may cause some data features to be lost

[0004] The aforementioned literature analyzes the voltage stability of AC and DC systems based on deterministic scenarios. When wind power is connected to the power system, the output of wind turbines is random and uncertain, and the deterministic voltage stability analysis method cannot fully reflect the system operation. state

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