Motor drive control including varying DC bus voltages, converter and inverter switching frequencies, and motor speed for thermal mitigation

A refrigeration system, comprising:

• a compressor motor;
• an inverter configured to convert a direct current (DC) bus voltage to an alternating current (AC) voltage and supply the AC voltage to the compressor motor;
• a converter configured to convert a DC input voltage to the DC bus voltage;
• and
• a control module configured to
• obtain at least one of a temperature of the control module or an ambient temperature;
• and
• based on the at least one of the temperature of the control module or the ambient temperature, reduce the DC bus voltage and at least one of (i) reduce a switching frequency of the inverter, or (ii) reduce a switching frequency of the converter.

A method of operating a refrigeration system, comprising:

• convert via a converter a direct current (DC) input voltage to a DC bus voltage, wherein the converter is a DC-to-DC boost converter;
• converting the DC bus voltage to an alternating current (AC) voltage and supplying the AC voltage to drive a compressor motor;
• detecting a temperature of the converter;
• obtaining an ambient temperature;
• and
• in response to (i) the temperature of the converter exceeding a predetermined threshold, and (ii) the ambient temperature being within a first predetermined temperature range, reducing a switching frequency from a first switching frequency to a second switching frequency and reducing the DC bus voltage from a first DC bus voltage to a second DC bus voltage, wherein the switching frequency is a switching frequency of a switch of the converter.

A refrigeration system, comprising:

• a compressor motor;
• an inverter configured to convert a direct current (DC) bus voltage to an alternating current (AC) voltage and supply the AC voltage to the compressor motor;
• a converter configured to convert a DC input voltage to the DC bus voltage;
• and
• a control module configured to
• obtain at least one of a temperature of the inverter, a temperature of the control module, or an ambient temperature;
• and
• based on the at least one of the temperature of the inverter, the temperature of the control module, or the ambient temperature, reduce the DC bus voltage and reduce a switching frequency of the converter.