Controller for load drive system

A controller for a load drive system,

• the load drive system comprising:
• a converter configured to boost or lower an output voltage of a DC power supply;
• an inverter configured to transform a DC voltage outputted from the converter into a three-phase AC voltage to be applied onto a load;
• and
• a smoothing capacitor provided in parallel between the converter and the inverter,
• the controller comprising:
• an inverter controller configured to PWM control the inverter with a two-phase modulation;
• and
• a converter controller configured to PWM control the converter,
• wherein a frequency of an inverter carrier signal used by the inverter controller to PWM control the inverter and a frequency of a converter carrier signal used by the converter controller to PWM control the converter are set so that a generation timing of an input current to the inverter and a generation timing of an output current from the converter coincide with each other every one or more cycles of the respective carrier signals, and
• wherein there is provided a correction means configured to, when the generation timing of the input current and the generation timing of the output current do not coincide with each other upon a change of the generation timing of the input current to the inverter with the frequencies of the respective carrier signals unchanged, correct these generation timings so as to coincide with each other.