Improvement of the Single-Phase Multifunctional Converter for Combined Electric Power System

摘要

The paper is devoted to the improvement of a single-phase converter for a combined electric power system with a photovoltaic solar battery, ensuring the quality of the current at the point of common coupling in almost the entire range of values and reducing energy losses in the switches of converter. The dependencies of the pulsations amplitude in inverter output current and error for a basic harmonic according to inverter input voltage, modulation frequency and inductance of output reactor are obtained. Introduction of compensating links for elimination of current control loop error is proposed. Voltage regulation at inverter input according to grid voltage and regulation of modulation frequency according to the reference of the grid current to reduce losses of the switches are also proposed. The structure of the converter control system with the change of the parameters setting is developed. The simulation of the system “grid - converter - nonlinear load” with the calculation of power losses is carried out.