METHOD OF STABILIZING OUTPUT VOLTAGE OF MULTILEVEL VOLTAGE INVERTER Russian patent published in 2020 - IPC H02M5/451 

FIELD: power electronics.

SUBSTANCE: invention relates to power electronics and can be used for construction of centralized power supply systems requiring stabilization of output voltage at change of parameters of primary and secondary power supply networks in a wide range. Method can be implemented in a frequency converter with n adjustable control system of direct current links (DCL), on the basis of which k=2n+1 levels of inverter input voltage are generated. For inverter output voltage curve, shape of which is considered to be optimum, inverter input voltage levels are rated values, as well as switching moments of power switches of inverter, additionally control system discretely with constant frequency, which is higher than output frequency of multilevel inverter by at least 360 times, measuring values of output voltages of DC links, based on which their effective values are calculated, measuring value of output voltage of inverter on load, calculating its effective value and calculating deviation of output voltage from rated voltage, when deviation of the output voltage of the permissible value exceeds the value of variation of switching moments of power inverters of the inverter as the difference between squares of the actual values of output and nominal voltages referred to the square of the actual value of the output voltage of the nth link of direct current and multiplied by π/2, and correcting switching moments of power switches of inverter by value of calculated variation. Method combines speed of output voltage stabilization process due to PWM and process of stabilization of voltage levels of multilevel inverter along DCL converter circuits.

EFFECT: increased efficiency of output voltage stabilization system of multilevel voltage inverter.

1 cl, 2 dwg