Power flow obtaining method applicable to AC and DC system

Abstract

The invention discloses a power flow obtaining method applicable to an AC and DC system. The power flow obtaining method comprises the steps of: firstly, establishing an AC and DC power system power flow model including an AC network model, a DC network model and a converter model, then, relaxing the AC and DC power system power flow model to a second-order cone form by adopting a cone relaxationtechnology, and finally, on this basis, obtaining a piecewise linearization AC and DC power system power flow model according to a second-order cone linearization method, wherein the linearization precision can be adjusted through a zooming method and changing of a piecewise number index. According to the power flow obtaining method applicable to the AC and DC system disclosed by the invention, the cone relaxation technology and the second-order cone linearization technology are adopted; the original non-convex nonlinear AC and DC power flow equation is converted into the convex piecewise linearization form; the operation economy of the whole AC and DC system can be improved; and simultaneously, the power flow obtaining method is also more suitable for processing all kinds of operation optimization problems having relatively high timeliness requirements in the power system.

Description

technical field [0001] The invention belongs to the field of electrical engineering, and more specifically relates to a power flow acquisition method suitable for AC and DC systems. Background technique [0002] With the development of voltage source converter and DC transmission technology, my country's power system has gradually evolved into an AC-DC interconnection system. However, the linear DC power flow model of the AC system widely used today considers that the system node voltage is fixed at 1p.u. However, the DC line transmission power requires a voltage difference, so the DC power flow model is no longer applicable to the DC network; Accurate AC-DC power system power flow model takes into account the AC power flow model and the exact model of the converter station. Its mathematical form is too complex, and it is difficult to calculate and solve. It is a non-convex and nonlinear model, and it cannot guarantee the global optimum when used in optimization problems. T...

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Problems solved by technology

[0003] Aiming at the above defects or improvement needs of the prior art, the present invention proposes a power flow acquisition method suitable for AC and DC systems, aiming to effectively solve the optimization problem when applying the original equation, which is difficult to solve by conventional methods and may fall into a local optimal solution The problem

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