Electric electronic multi-infeed power system low-interference stability evaluation method

Abstract

The invention discloses an electric electronic multi-infeed power system low-interference stability evaluation method. An electric electronic equipment reference capacity diagonal matrix is obtained by electric electronic equipment parameters in an electric electronic multi-infeed power system, the matrix is converted into an inverse matrix, a receiving-end AC power grid obtains an equivalent admittance matrix through Thevenin equivalence, and an extended Jacobian matrix is obtained by multiplying the inverse matrix by the equivalent admittance matrix; according to a feature value of the extended Jacobian matrix, the electric electronic multi-infeed power system is equivalent to multiple electric electronic single-infeed power systems, and a generalized short circuit ratio of the electric electronic multi-infeed power system is obtained; and according to the generalized short circuit ratio of the electric electronic multi-infeed power system, low-interference stability is determined. According to the invention, a newly defined generalized short circuit ratio is brought forward, the physical mechanism is clear, and the method can be applied to low-interference stability evaluation of the electric electronic multi-infeed power system and enables the electric electronic multi-infeed power system to run stably.

Description

technical field [0001] The invention relates to a small-disturbance stability evaluation method, in particular to an evaluation method for small-disturbance stability of a power electronic multi-infeed power system. Background technique [0002] With the rapid development of new energy, the proportion of new energy such as photovoltaic power generation and wind power generation in the power structure is increasing. It is inevitable that multiple new energy sources will be connected to the same AC power grid at the receiving end, and a large number of new energy sources will be connected to the power grid using power electronic equipment. , these new energy sources with close electrical distances and the AC receiving end grid together constitute a power electronic multi-infeed power system. When the number and capacity of power electronic devices fed into the AC grid increase, the AC system becomes relatively weaker and its strength decreases, which leads to the intensificati...

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Problems solved by technology

[0005] However, the existing concept of generalized short-circuit ratio is derived based on the static voltage stability problem of multi-feeding traditional DC, and can only deal with the bifurcation problem of the zero-frequency band of traditional DC

For common power electronics (such as VSC type power electronic equipment used in wind power, photovoltaic and light DC, etc.), the multi-infeed AC system is not applicable, nor can it be used to analyze the small disturbance stability characteristics of the system

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