由于大量新型电力电子设备在微电网中的应用，以及微电网中负载的非线性特点

Due to the application of a large number of new power electronic equipment in the microgrid and the non-linear characteristics of the load in the microgrid, the harmonic problem is particularly prominent in the power quality problem of the microgrid. The management of harmonics depends on accurate harmonic detection technology. Therefore, accurate detection of harmonics in the microgrid is also the current key research direction. The detection of harmonics must be fast and accurate, in addition, it must meet certain economic requirements. The current detection methods for power system harmonics are: fast Fourier transform detection method, instantaneous reactive power theory method, neural network-based detection method and wavelet analysis detection method. Harmonic detection theory has been able to be realized in practice, but there is still room for research progress to make it more perfect. For example, when the Fourier transform method is used to detect harmonics in the power grid, there will be spectrum side leakage and fence phenomena in the process of signal analysis, and it is very difficult to locate the occurrence and end time of transient signals; The detection method of the power power theory, its control circuit and detection algorithm are relatively complex, and its detection accuracy is greatly affected by the filter, which has certain limitations.

Because of the application of a large number of new power electronic equipment in the microgrid, as well as the nonlinear characteristics of the load in the microgrid, the harmonic problem is particularly prominent in the power quality problem of the microgrid, and the control of harmonics relies on precise harmonic detection technology, so the precise detection of harmonics in the microgrid is also the focus of research. The detection of harmonics should be fast and accurate, and certain economic requirements should be met. At present, the detection methods of the harmonics of power system are: rapid Fourier transformation detection method, instantaneous reactive power theory method, neural network-based detection method and wavelet analysis detection method. Harmonic detection theory can be realized in practice, but there is still room for research and progress to make it more perfect. For example, when using the Fourier transformation method to detect the harmonics of the power grid, there will be spectrum side leakage and the appearance of fence phenomenon in the process of signal analysis, and it is very difficult to locate the occurrence and end time of transient signals;

Due to the application of a large number of new power electronic equipment in the microgrid and the nonlinear characteristics of the load in the microgrid, the harmonic problem is particularly prominent in the power quality problem of the microgrid. The treatment of harmonic depends on the accurate harmonic detection technology, so the accurate detection of harmonic in the microgrid is also the current research direction. The detection of harmonics should be fast and accurate, and also meet certain economic requirements. At present, the detection methods of power system harmonic mainly include: Fast Fourier transform detection method, instantaneous reactive power theory method, neural network based detection method and wavelet analysis detection method. Harmonic detection theory can be realized in practice, but there is still room for research and progress to make it more perfect. For example, when using the Fourier transform method to detect the harmonic of the power grid, there will be spectrum side leakage and fence phenomenon in the process of signal analysis, and it is very difficult to locate the occurrence and end time of the transient signal; the detection method based on the instantaneous reactive power theory has relatively complex control circuit and detection algorithm, and its detection accuracy is greatly affected by the filter , with certain limitations.