System and method for calculating parameters for a refrigeration system with a variable speed compressor

A method comprising:

• receiving a condenser signal corresponding to at least one of a condenser pressure and a condenser temperature of a condenser connected to a compressor and an evaporator;
• modulating a speed of said compressor with an inverter drive configured to modulate electric power delivered to said compressor;
• receiving electric power data and compressor speed data from said inverter drive;
• receiving a discharge temperature signal from a discharge temperature sensor, said discharge temperature signal corresponding to a temperature of refrigerant exiting said compressor;
• calculating at least one of an evaporator temperature and an evaporator pressure based on said condenser signal, said discharge temperature signal, said electrical power data, and said compressor speed data.

A system comprising:

• a compressor connected to a condenser and an evaporator;
• a condenser sensor that outputs a condenser signal corresponding to at least one of a condenser pressure and a condenser temperature;
• a discharge temperature sensor that outputs a discharge temperature signal corresponding to a temperature of refrigerant exiting said compressor;
• an inverter drive that modulates electric power delivered to said compressor to modulate a speed of said compressor;
• a control module that is connected to said inverter drive, that receives said condenser signal and said discharge temperature signal, that monitors electrical power data and compressor speed data from said inverter drive, and that, to protect said compressor from floodback and overheat conditions, calculates at least one of an evaporator temperature and an evaporator pressure based on said condenser signal, said discharge temperature signal, said electrical power data, and said compressor speed data.

A method comprising:

• receiving a condenser signal corresponding to at least one of a condenser pressure and a condenser temperature of a condenser connected to a compressor and an evaporator;
• modulating a speed of said compressor with an inverter drive configured to modulate electric power delivered to said compressor;
• receiving electric power data and compressor speed data from said inverter drive;
• receiving a discharge temperature signal from a discharge temperature sensor, said discharge temperature signal corresponding to a temperature of refrigerant exiting said compressor;
• and
• to protect said compressor from floodback and overheat conditions, calculating at least one of an evaporator temperature and an evaporator pressure based on said condenser signal, said discharge temperature signal, said electrical power data, and said compressor speed data.