Load characteristic-based classification low-voltage load shedding method and system

Abstract

The invention relates to a load characteristic-based classification low-voltage load shedding method and system. The load characteristic-based classification low-voltage load shedding method comprises the following steps of 1) analyzing dynamic response characteristic of a load to obtain a Q-V relation characteristic curve of load reactive power changing with a voltage; 2) making an initial low-voltage load shedding scheme according to an existing method by taking a dynamic motor load as a basic load; 3) determining replacement parameters of the load under different voltage levels according to the Q-V relation characteristic curve; 4) proposing a mode of configuring the classification low-voltage load shedding measure to remove each load capacity according to the replacement coefficients; and 5) verifying and determining a final classification low-voltage load shedding scheme by simulation calculation. The technical scheme lies in that the defect of an existing low-voltage load shedding measure is made up, and a risk of large-area failure of a power grid is reduced.

Description

technical field [0001] The invention relates to the technical field of power system stability control, in particular to a classified low-voltage load shedding method based on load characteristics and a system thereof. Background technique [0002] Large-scale load centers in my country, such as Beijing, Shanghai, and Guangdong, all have the following things in common: (1) Due to the constraints of energy, environmental protection and land resources, there are fewer and fewer power plants in the central load area, and the proportion of power transmission outside the area is increasing . (2) The proportion of air-conditioning load in the load center is increasing, and its number increases and decreases sharply with the weather, which is difficult to predict. (3) The number of parallel devices (parallel capacitor compensation devices, filters, etc.) for capacitive intermittent regulation in the power grid is huge. (4) With the wide application of power electronics technology, ...

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Problems solved by technology

(2) The proportion of air-conditioning load in the load center is increasing, and its number increases and decreases sharply with weather changes, which is difficult to predict

(4) With the wide application of power electronics technology, the sensitivity of many loads to voltage is reduced, similar to the property of constant power, which is not conducive to the recovery of voltage

However, when the power grid actually formulates the low-voltage load shedding scheme, it still adopts the method and mode similar to the low-frequency load shedding configuration. The reasons are as follows: (1) The load element itself is uncertain and time-varying; (2) The difference in dynamic characteristics of various load elements makes the comprehensive load characteristics of the receiving side also have uncertainty and time-varying; ( 3) The low-voltage load shedding scheme required by the grid side is difficult to implement on the user side at the end of the distribution network; (4) The low-voltage load shedding scheme needs to be verified through dynamic simulation to verify the effectiveness of the scheme and parameters, although it has been widely used in voltage stability research. Recognize the importance and necessity of classified low-voltage load shedding schemes, but due to the delay in the development of simulation programs, most of the current research is still limited to the influence of certain comprehensive load model characteristics

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