A security and stability risk quantitative assessment method considering the uncertainty of new energy

Abstract

The invention discloses a security and stability risk quantitative assessment method that takes into account the uncertainty of new energy. The first step is to obtain basic power grid information; and the second step is to calculate the frequency, voltage and power angle stability of the power grid under different grid-connected output scenarios of new energy. Safety-constrained new energy maximum low penetration and maximum off-grid capacity Step 3: Based on offline analysis of new energy with different grid-connected output scenarios, the grid can withstand the maximum low-throughput and maximum off-grid capacity of new energy, and conduct online new energy output Match the scenarios and methods, and calculate the actual low-penetration amount P of the new energy that takes into account the low-penetration and high-penetration values ​​of the new energy power station under different expected faults lc , off-net quantity P tw Step 4: Calculate the security and stability risk quantification index η and λ taking into account the uncertainty of low penetration and off-grid of new energy under different expected faults, so as to determine the most serious fault of the power grid. The invention fully considers the uncertainty of new energy, quantifies the risk of fault operation, and can effectively guide the safe and stable operation of the power grid.

Description

technical field [0001] The invention relates to a security and stability risk quantitative assessment method taking into account the uncertainty of new energy, and belongs to the technical field of power system security and stability control. Background technique [0002] With the large-scale connection of new energy and direct current to the power grid in recent years, a large number of new energy sources have replaced conventional power sources, the primary frequency regulation capability and dynamic reactive power support of the power grid have declined, the moment of inertia of the system has been greatly reduced, and the frequency and voltage stability and anti-disturbance capabilities have deteriorated. At the same time, the volatility of new energy output makes it more difficult to pre-control the section during the operation of the all-clean energy grid. Under certain operating conditions, it will lead to the problem that the security control strategy is not suitable...

AI Technical Summary

Problems solved by technology

[0002] With the large-scale access of new energy and DC to the power grid in recent years, a large number of new energy sources have replaced conventional power sources, the power grid's primary frequency regulation capability and dynamic reactive power support have declined, the system's moment of inertia has been greatly reduced, and frequency, voltage stability and anti-disturbance capabilities have deteriorated

At the same time, the fluctuation of new energy output makes it more difficult to pre-control the section when the clean energy grid is running

Under certain operating conditions, it will lead to the problem that the safety control strategy is not suitable or the amount of measures is insufficient, and the operation control of the power grid is facing new challenges

[0003] The source network characteristics and fault evolution characteristics of modern power systems have undergone tremendous changes, and the uncertainty of new energy output and transient evolution characteristics has made it difficult to adapt to the traditional severe fault risk assessment

Large-scale new energy grid integration and demand-side interaction will bring more complexity, uncertainty and risk to the operation of large power grids

[0004] At present, power planning and operation departments usually use deterministic methods to evaluate system stability, but this method ignores the impact of unrestricted faults on system instability risk

In the past, the three lines of defense established based on the evolution of deterministic events had insufficient control and caused secondary stability problems. It is urgent to carry out quantitative analysis of the severity of faults under the influence of new energy output and transient evolution of new energy after failures.

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