System for controlling operation of an HVAC system

1. A control system for a compressor assembly of an heating, ventilation, and air conditioning (HVAC) system, the control system comprising:

a control assembly configured to operationally connect to a compressor assembly of an HVAC system, wherein the control assembly is configured to vary a capacity of a compressor unit of the compressor assembly;

wherein the control assembly comprises a controller configured to vary the input power delivered to the compressor unit;

wherein the controller is configured to:

determine, when the compressor unit is operating in a first operating state in the HVAC system, a power factor ratio, an input voltage, and an input current of the compressor unit, the power factor ratio being a ratio of power delivered to the compressor unit relative to power consumed by the compressor unit;

determine, based on the power factor ratio, the input voltage, and the input current of the first operating state, a power of the compressor;

determine a pressure of the compressor unit operating in the first operating state, wherein the pressure of the compressor unit is determined by calculating the pressure of the compressor unit as a function of the power of the compressor, outdoor temperature, indoor temperature, and indoor airflow rate; and

determine, based on the pressure of the compressor unit, that there is a problem with the compressor unit.

2. The control system of claim 1 , wherein the pressure of the compressor unit is selected from a suction pressure and a discharge pressure of the compressor unit.

3. The control system of claim 1 , wherein the controller generates an operating signal based on the pressure of the compressor unit.

4. The control system of claim 3 , wherein the operating signal generated by the controller is a command configured to vary the capacity of the compressor assembly from a first capacity of the first operating state to a second capacity of a second operating state.

5. The control system of claim 4 , wherein varying the capacity of the compressor assembly from the first capacity of the first operating state to the second capacity of a second operating state comprises varying the input power delivered to the compressor unit.

6. The control system of claim 3 , wherein the operating signal generated by the controller is a command configured to store, display, or communicate a predicted pressure.

7. The control system of claim 3 , wherein the control assembly further comprises:

an electrical power converter operationally connected to the controller, wherein the power converter is configured to adjust the input power to the compressor unit; and

wherein the controller is configured to determine the first operating state based on information received from the electrical power converter.

8. The control system of claim 7 , wherein electrical power converter comprises an inverter configured to drive the compressor unit.

9. The control system of claim 1 , wherein the pressure of the compressor unit is further calculated as a function of indoor supply air temperature.

10. A method for controlling operation of a compressor assembly of a heating, ventilation, and air conditioning (HVAC) system, the method comprising:

providing a control assembly configured to operationally connect to a compressor assembly of an HVAC system, wherein the control assembly is configured to vary a capacity of a compressor unit of the compressor assembly;

determining, when the compressor unit is operating in a first operating state in the HVAC system, a power factor ratio, an input voltage, and an input current, the power factor ratio being a ratio of power delivered to the compressor unit relative to power consumed by the compressor unit;

determining, based on the power factor ratio, the input voltage, and the input current of the first operating state, a power of the compressor;

determining a pressure of the compressor unit operating in the first operating state, wherein the pressure of the compressor unit is determined by calculating the pressure of the compressor unit as a function of the power of the compressor, outdoor temperature, indoor temperature and indoor airflow rate; and

determining, based on the pressure of the compressor unit, that there is a problem with the compressor unit.

11. The method of claim 10 , wherein the pressure of the compressor unit is selected from a suction pressure and a discharge pressure of the compressor unit.

12. The method of claim 10 , further comprising generating, by the controller, an operating signal based on the pressure of the compressor unit.

13. The method of claim 11 , wherein the operating signal generated by the controller is a command configured to vary the capacity of the compressor assembly from a first capacity of the first operating state to a second capacity of a second operating state.

14. The method of claim 13 , wherein varying the capacity of the compressor assembly from the first capacity of the first operating state to the second capacity of a second operating state comprises varying the input power delivered to the compressor unit.

15. The method of claim 12 , wherein the operating signal generated by the controller is a command configured to store, display, or communicate the predicted pressure.

16. The method of claim 12 , further comprising:

providing an electrical power converter operationally connected to the controller, wherein the power converter is configured to adjust the input power to the compressor unit; and

determining, by the controller, the first operating state of the compressor unit based on information received from the electrical power converter.

17. The method of claim 10 , wherein

the pressure of the compressor unit is further calculated as a function of indoor supply air temperature.