Abstract: A power conversion control device includes a modulation-wave generating unit generating a modulation wave based on output voltage phase angle command and modulation factor, a carrier-wave generating unit that, in a case of non-overmodulation state, generates a triangular wave or saw-tooth wave as the carrier wave, and, in a case of overmodulation state, generates, as the carrier wave, a signal fixed to ?1 in a first section that is a predetermined range centering on timing corresponding to a peak position of the modulation wave, generates, as the carrier wave, a signal fixed to +1 in a second section obtained by shifting the first section by a half cycle of the modulation wave, and generates, as the carrier wave, a triangular wave or saw-tooth wave in remaining third section, and a comparing unit that compares the carrier wave and the modulation wave and generates a switching signal.

Abstract: A hybrid-vehicle power generator control apparatus. Based on a difference electric power value, which corresponds to the difference between an electric power generator power command value given by a higher-hierarchy control unit and an output voltage value of an electric power generator, an electric power generator control unit calculates an electric power generator rotation speed command value and based on the calculated electric power generator rotation speed command value, the electric power generator control unit PWM-controls an output of the electric-power conversion system that performs electric conversion between the electric power generator and a battery, so that the rotation speed of the electric power generator is made to keep track of the electric power generator rotation speed command value and the output electric power value of the electric power generator is made to keep track of the electric power generator power command value.

Abstract: An over temperature protection device for electric motors applicable to a railway vehicle driving system that operates a plurality of electric motors in parallel using one or a plurality of inverter devices includes a control device configured to control the operation of an inverter device and a protecting device configured to detect, on the basis of a frequency fs including frequency information at the time when the inverter device is applying control for fixing a ratio of a voltage and a frequency to electric motors and electric currents of at least one phase flowing to the electronic motors, an over temperature that could occur in the electric motors, to generate an over temperature protection signal Tf for protecting the electric motors from the over temperature, and to output the over temperature protection signal Tf to the control device.