Research on Residual Current Protection Model of Distributed Photovoltaic Grid-Connected System Based on Multi-Point Collaboration

In this paper, multifunctional residual current protection strategy and protection early warning technology are studied to solve the problem of traditional two-stage/three-stage coordination failure of residual current protection. A residual current prediction method based on multi-source historical data is proposed, and a multi-point cooperative residual current protection early warning model is constructed. In this paper, the residual current characteristics of typical full-bridge circuits are studied. Coordinate conversion algorithm is adopted. This algorithm requires the construction of virtual vertical signal, so an orthogonal generation circuit of second-order generalized integral circuit is proposed to process the signal. The experimental results show that this algorithm can accurately calculate each component in the power system, and can adapt to the frequency of the power grid and has practical value. The research results of this project can effectively improve the operation rate, operation stability and accuracy of high voltage and large current transformer, which provides guarantee for the reliable operation of high voltage and low voltage power systems.