Improving quality of electricity generated by grid-tied inverters in solar power plants in low generated power mode using frequency adaptive PWM

Abstract The article presents the results of a study of the dependence of the quality indicators of electricity generated by solar power plants in three-phase electrical networks on the level of generated power. In the course of the study, it was established that when the generated power is reduced, the grid voltage inverters that are part of the solar power plants cause an increase in the share of higher harmonic currents to the electric grid. An analysis of international standards regarding the quality requirements of the generated current was performed, which showed that when the level of generated power decreases, the quality of electric energy decreases and may not meet the requirements of the standard. The algorithm of frequency-adaptive pulse-width modulation is proposed, which allows to improve the quality indicators of the electricity generated by the grid inverter of the voltage of the solar power plant to the electrical grid.