Electric power system risk assessment method based on deterministic analysis

Abstract

The invention discloses an electric power system risk assessment method based on the deterministic analysis. The tide current shifting and node voltage changing caused after a system is disturbed are comprehensively taken into consideration, and a more thorough power grid vulnerability comprehensive analysis index is put forward. The method comprises the following steps that firstly, a system topological structure is analyzed, the tide current distribution of the system after stable running and disturbing is calculated and comprises active tide current and reactive tide current of branch circuits, node voltages and a phase angle difference of the node voltages; secondly, assessment indexes in an assessment system are calculated and comprise a pre-risk assessment factor and a network comprehensive risk assessment factor; thirdly, risk assessment is carried out on an electric power system according to the set index levels. According to the electric power system risk assessment method, the system risk information is more comprehensively reflected, a unified index risk decision is made for tide current threshold-crossing, voltage instability and cascading failure possibly existing in the system, and operators can make rapid and accurate judgment and take measures to guarantee safe and stable running of the system in time.

Description

technical field [0001] The invention relates to a power system risk assessment method based on deterministic analysis, which relates to the field of power grid risk assessment. Background technique [0002] In recent years, there have been many large-scale power outages around the world, which have caused a very large impact. Most of these accidents are due to the large-scale power flow transfer caused by the failure of one or several operating components, which leads to overload tripping of some lines, voltage collapse, and then cascading failures. In fact, in the initial stage of power flow transfer, not all lines will be overloaded, but only part of the power flow will change sharply, even causing chain trips. The power system is a complex nonlinear system. How to discover these vulnerable parts in time after the system is disturbed, that is, to identify the key nodes and lines in the power grid, has important applied research value. [0003] In the previous determinist...

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Problems solved by technology

In fact, when the power grid fails, the disconnection of a line will inevitably transfer the power flow of this line to other lines, so that the active power flow of the other lines may increase significantly, and the resulting increase in current will also make the power flow of the transmission line unusable. The power loss increases, which increases the voltage loss on the line. When there is no sufficient reactive power compensation, the node voltage will inevitably drop, and even a voltage collapse will occur in severe cases, which will also lead to large-scale power outages in the power grid.

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