Inverter controller and refrigerating and air-conditioning unit

An inverter controller controlling an inverter main circuit which drives a load such as a motor by converting a direct current power of a direct current power source into an alternating current power, the inverter controller comprising:

• a PWM signal generating part which generates a PWM signal to control on-off of a plurality of switching elements configuring the inverter main circuit;
• an operating state detecting part which detects an operating state of the load based on a direct current bus voltage of the inverter main circuit, a motor current which flows between the inverter main circuit and the load and an operation instruction to the load;
• a gate resistance selecting signal generating part which generates a gate resistance selecting signal corresponding to the operating state of the load;
• and
• a gate resistance selecting part which selects gate resistances connected to gate terminals of the switching elements of the inverter main circuit by using the gate resistance selecting signal.