Wind power plant cable insulation online monitoring method and device

Abstract

The invention relates to a wind power plant cable insulation online monitoring method and device. The method comprises the steps of obtaining the inherent high-frequency resonant frequency of a wind power plant through the voltage and current values of an AC bus of the wind power plant, judging whether a cable is aged or not, calculating a high-frequency resonant frequency value through employing a particle swarm algorithm under the condition that the cable is aged, and obtaining the aging degree of the monitored cable according to a calculation result. According to the online monitoring method and device provided by the invention, cable insulation aging monitoring is carried out by utilizing inherent high-frequency resonance in a wind power plant system, whether the cable is aged or not can be quickly and accurately judged only by acquiring voltage and current information on the bus in the wind power plant without additionally installing a sensor, and when the cable is aged, the high-frequency resonant frequency value is calculated by adopting the particle swarm algorithm, so that quantitative estimation of the aging degree is realized.

Description

technical field [0001] The invention relates to the technical field of on-line monitoring of cable insulation status, in particular to a method and device for on-line monitoring of cable insulation in a wind farm. Background technique [0002] The energy crisis has promoted the rapid development of the wind power industry. As of the end of 2019, the total installed capacity of wind power in the world has reached 650.8GW, and it is still rising. Among them, more than 50% of the installed wind power capacity is achieved by double-fed wind turbines. For wind farms, especially offshore wind farms, the cable system is the main way of power transmission. However, cables in wind farms are more prone to aging than cables in traditional power grids due to the following reasons: (1) Due to the variability of wind speed, the current of wind farms is often between the minimum and maximum values ​​in a short period of time The rapid change makes the cable insulation withstand a large ...

AI Technical Summary

Problems solved by technology

[0004] Disadvantages of the partial discharge method: (1) It is difficult to quantitatively estimate the degree of aging; (2) High-frequency measurement devices are required, and sensors need to be distributed, resulting in high measurement costs; (3) Susceptible to harmonic interference in the system

In wind farms with doubly-fed wind turbines as the main body, there are often abundant harmonic components, which will greatly reduce the accuracy of the partial discharge method

Disadvantages of the method based on time-frequency domain reflection: (1) The monitoring accuracy is limited, and it is mostly used for locating system faults, and it is difficult to describe the overall change of insulation parameters; (2) Additional signal injection and measurement devices are required, and the cost is high. Difficult to install in wind farms

Images