Automatic Calculation Method of Load Resonant Frequency of Photovoltaic Power Supply

Abstract

The resonance phenomenon of photovoltaic power supply load makes the output voltage of grid-connected photovoltaic power supply system difficult to keep stable, which brings trouble to power supply. Therefore, it is necessary to study the automatic calculation method of load resonance frequency of photovoltaic power supply, so as to detect the load resonance frequency of photovoltaic power supply in real time, thereby ensuring the normal operation of photovoltaic power supply system. The load resonance frequency of photovoltaic power supply is divided into steady-state load resonance frequency and dynamic load resonance frequency. The mathematical model of load resonant circuit of photovoltaic power supply is established by calculating algorithm of load resonant frequency of photovoltaic power supply in steady state, and load resonant frequency of photovoltaic power supply in steady state is calculated. The resonance detection algorithm based on wavelet transform and Hilbert-Huang transform is used to analyze and calculate the load resonance frequency after detecting the resonance signal of photovoltaic power system. The experimental results show that the resonant frequency of photovoltaic power supply load calculated by this method is not much different from the actual resonant frequency of photovoltaic power supply load, and the error range is between-0.30% and 0.49%. Therefore, this method can keep the load resonance frequency of the photovoltaic power supply the same as the RF transmission resonance frequency, and can ensure the normal operation of the photovoltaic power supply.