Microgrid inverter fault diagnosis method based on wavelet transformation and probabilistic neural network

Abstract

The invention provides a microgrid inverter fault diagnosis method based on wavelet transformation and a probabilistic neural network. The method comprises the steps that firstly, building a fault simulation system of the microgrid inverter on simulation software, then collecting three-phase load currents under different fault types to serve as measurement signals, and extracting fault characteristic signals of the three-phase load currents through a wavelet multi-resolution analysis method; carrying out normalization processing on the extracted fault feature signal to construct a feature vector; and finally, selecting a part of the extracted fault feature vectors as training data to train the PNN model, and when a genetic algorithm is adopted to find an optimal smoothing factor of the probabilistic neural network, and when the inverter has a fault, carrying out fault positioning on a current signal according to the method, thereby realizing fault diagnosis of the microgrid inverter. The method has the advantages that the structure model is simple, determination is easy, the convergence speed is high, a Bayes optimization solution is converged, the sample adding capacity is high, retraining is not needed, the precision is high, the practicability is high, and engineering combination is easy.

Description

technical field [0001] The invention relates to the field of fault diagnosis of power electronics, in particular to a fault diagnosis method for a microgrid inverter based on wavelet transform and probabilistic neural network. Background technique [0002] Today, with the global economy, the rapid development of science and technology and the increasing scale of industrialization. People's demand for energy is increasing day by day. With the continuous depletion of traditional energy sources such as coal and oil and the serious pollution to the environment, countries around the world have gradually realized the importance of energy and the environment. Therefore, vigorously develop clean energy such as solar energy and wind energy. Distributed power generation is an effective way to utilize clean energy, and the microgrid is a low-voltage system composed of distributed power sources, energy storage, and loads. As an important bridge and link between the large power grid a...

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Problems solved by technology

[0005] In order to solve the problem that the types of faults of switching devices of micro-grid inverters are complicated, and the traditional manual search can no longer satisfy the rapid popularization

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