US Patent 12077031 Variable speed for transport englineless refrigeration unit

A transportation refrigeration unit for cooling a cargo compartment includes a compressor configured to compress a refrigerant, a compressor motor configured to drive the compressor, an evaporator heat exchanger operatively coupled to the compressor and an evaporator fan configured to provide return airflow from a return air intake and flow the return airflow over the evaporator heat exchanger. A drive unit is configured to deliver variable frequency electrical power between a minimum frequency and a maximum frequency to the compressor motor and the evaporator fan. A frequency of the electrical power is based on one or more sensed parameters of the transportation refrigeration unit.