Drive control device, electrical apparatus and drive control method

A drive control device for controlling drive of an electrical apparatus, which includes a rotor provided on a rotating shaft rotated by an electric motor driven by an inverter for converting a frequency of an AC power supply, comprising:

• a physical amount detection unit for detecting a plurality of physical amounts pertaining to an output of the electric motor;
• a storage unit for storing threshold values for the physical amounts;
• a rotational frequency determination unit for determining whether or not a rotational frequency of the electric motor is equal to or greater than a base rotational frequency;
• a selection unit for selecting a threshold value for each of the physical amounts in accordance with a determination result obtained by the rotational frequency determination unit;
• and
• a control unit for controlling a rotational frequency of the rotating shaft in accordance with a magnitude relationship between a physical amount detected by the physical amount detection unit and a threshold value selected by the selection unit.

A drive control device for controlling drive of an electrical apparatus, which includes a rotor provided on a rotating shaft rotated by an electric motor driven by an inverter for converting a frequency of an AC power supply, comprising:

• a physical amount detection unit for detecting a feature amount pertaining to a torque of the electric motor;
• a threshold value calculation unit for calculating a feature amount threshold value for the feature amount;
• and
• a control unit for controlling, in operating the electric motor at a rotational frequency equal to or greater than a base rotational frequency, a rotational frequency of the rotating shaft in accordance with a magnitude relationship between the feature amount detected by the physical amount detection unit and the feature amount threshold value calculated by the threshold value calculation unit.

A drive control device for controlling drive of an electrical apparatus, which includes a rotor provided on a rotating shaft rotated by an electric motor driven by an inverter for converting a frequency of an AC power supply, comprising:

• a physical amount detection unit for detecting an output of the electric motor;
• a threshold value calculation unit for calculating a power threshold value for the output of the electric motor;
• and
• a control unit for controlling, in operating the electric motor at a rotational frequency equal to or lower than a base rotational frequency, a rotational frequency of the rotating shaft in accordance with a magnitude relationship between the output detected by the physical amount detection unit and the power threshold value calculated by the threshold value calculation unit.

A drive control method for an electrical apparatus, which includes a rotor provided on a rotating shaft rotated by an electric motor driven by an inverter for converting a frequency of an AC power supply, comprising the steps of:

• detecting a plurality of physical amounts pertaining to an output of the electric motor;
• determining, with threshold values for the physical amounts stored, whether or not a rotational frequency of the electric motor is equal to or greater than a base rotational frequency;
• selecting a threshold value for each of the physical amounts in accordance with a determination result obtained in the determining step;
• and
• controlling a rotational frequency of the rotating shaft in accordance with a magnitude relationship between a detected physical amount and a selected threshold value.

A drive control method for an electrical apparatus, which includes a rotor provided on a rotating shaft rotated by an electric motor driven by an inverter for converting a frequency of an AC power supply, comprising the steps of:

• detecting a feature amount pertaining to a torque of the electric motor;
• calculating a feature amount threshold value for the feature amount;
• and
• controlling, in operating the electric motor at a frequency equal to or greater than a base rotational frequency, a rotational frequency of the rotating shaft in accordance with a magnitude relationship between the detected feature amount and the calculated feature amount threshold value.

A drive control method for an electrical apparatus, which includes a rotor provided on a rotating shaft rotated by an electric motor driven by an inverter for converting a frequency of an AC power supply, comprising the steps of:

• detecting an output of the electric motor;
• calculating a power threshold value for the output of the electric motor;
• and
• controlling, in operating the electric motor at a rotational frequency equal to or lower than a base rotational frequency, a rotational frequency of the rotating shaft in accordance with a magnitude relationship between the detected output and the calculated power threshold value.