The application provides a
core temperature balancing modulation method of a three-level
inverter circuit, and belongs to the technical field of power electronic power conversion. The method is applied to a three-level
inverter circuit comprising a first outer tube, a second outer tube, a first inner tube, a second inner tube, a first freewheeling tube and a second freewheeling tube. The
threshold temperature of the outer tube and the
threshold temperature of the inner tube are determined through testing and
simulation, and the outer tube module temperature and the inner tube module temperature are obtained. When the outer tube module temperature exceeds the
threshold temperature of the outer tube and the
temperature difference condition is met, the inner and outer tube mixed modulation mode is entered. In the mode, the outer tube modulation mode and the inner tube modulation mode are switched according to the comparison result of the instantaneous output current and the
current threshold, and the
current threshold is adjusted according to the outer tube module temperature and the inner tube module temperature. Thus, the distribution of high-frequency switching loss of the inner and outer tubes can be dynamically adjusted according to the actual temperature rise state, and the
core temperature balancing effect of the inner and outer tubes is improved.