Detection of Nonlinear Behavior in Voltage Source Converter Control in Wind Farms Based on Higher-Order Spectral Analysis

• DOI: 10.48550/arxiv.2210.09187
• Publication Date: 2022-01-01
• Authors: Zetian Zheng; Chen Shen
• Keywords: Bicoherence; Trispectrum; Describing function; Oscillation (cell signaling)

In recent years, the sub-synchronous oscillation (SSO) accidents caused by wind power have received extensive attention. A method is needed to distinguish if nonlinear behavior exists in recorded equal-amplitude accident waveforms, so that different methods can be adopted analyze mechanism of oscillation. The theory higher-order statistics (HOS) has become a powerful tool for detection (DNB) production quality control since 1960s. However, HOS analysis been applied mechanical condition monitoring and fault diagnosis, even after being introduced into system farms. This paper focuses on voltage source converter (VSC) systems farms tries detect bilateral or unilateral saturation hard limits based analysis. First, traditional describing function extended obtain more frequency domain information, hereby harmonic characteristics limit are studied. Then bispectrum trispectrum as HOS, which bicoherence tricoherence spectrums eliminate effects from linear parts VSC system. effectiveness DNB classification strictly proved its detailed calculation estimation process illustrated. Finally, proposed demonstrated further discussed through simulation results.