Method and apparatus for adjusting the reference impedance of a power generator
View Patent ↗A method and apparatus for allowing the user of a power generator coupled to a time-varying load, to define an alternative reference impedance to enable on or more metrics to be provided relative to the alternative reference impedance. The metrics, for example, may provide indicia of performance of the power generator system. One illustrative embodiment provides a power delivery system that applies power to a plasma chamber to create a plasma therein; determines a reference impedance of the plasma at an operating condition; and controls the power delivery system based on the determined reference impedance.
1. A power delivery system for applying power to a load comprising a load impedance, the system comprising:
a power generator comprising a reference impedance configured to apply power to the load; and
a performance assessor electrically coupled to the power generator and the load, the performance assessor configured to,
provide indicia of operational performance of the power delivery system, the indicia of the operational performance being relative dependent upon the reference impedance,
substitute the load impedance for the reference impedance in the indicia of operational performance, and
enable the indicia of the operational performance to be changed to a desirable range.
2. The power delivery system of claim 1 wherein, the performance assessor is further configured to receive the reference impedance of the load from a user of the power generator.
3. The power delivery system of claim 1 wherein the performance assessor further comprises:
a coupler to measure a forward voltage signal and a reflected voltage signal; and
a controller configured to determine a forward power, a reflected power, and the load impedance, wherein each of the forward power, reflected power, and load impedance are based on the forward voltage signal and the reflected voltage signal.
4. The power delivery system of claim 3 wherein the indicia of operational performance is reflected power.
5. The power delivery system of claim 3 wherein the controller is further configured to calculate a reflection coefficient.
6. The power delivery system of claim 3 wherein the controller is further configured to calculate a minimum reflected power.
7. The power delivery system of claim 3 wherein the controller is further configured to calculate a maximum delivered power.
8. A method of managing an application of power with a power generator to a load, comprising:
electrically coupling a performance assessor to the power generator and the load, wherein the power generator comprises a reference impedance;
receiving from the performance assessor an indicia of operational performance of the power delivery system,
receiving from the performance assessor an indication of an effectiveness of the application of power relative to the reference impedance;
receiving an operational load impedance value, the operational load impedance value differing from the reference impedance;
using the operational load impedance value to provide another indication of the effectiveness of the application of power; and
utilizing the another indication of the effectiveness of the application of power to manage the application of power to the load.
9. The method of claim 8 , further including: adjusting the application of power so as to maximize the application of power to the load.
10. The method of claim 8 wherein adjusting the application of power includes:
measuring a forward voltage from the power generator;
measuring a reflected voltage from the load; and
calculating a forward power, a reflected power and the operational load impedance from the measured forward voltage and from the measured reflected voltage.
11. The method of claim 10 further comprising calculating a reflection coefficient.
12. The method of claim 10 further comprising calculating a minimum reflected power.
13. The method of claim 10 further comprising calculating a maximum delivered power.
14. The method of claim 8 , wherein the indication of an effectiveness of the application of power is reflected power.
15. A method of controlling a power generation system, comprising:
providing a power generator, having a predefined reference impedance, the power generator configured to deliver power to a load having an operational impedance different from the predefined reference impedance;
applying power from the power generator to the load; and
determining an operational efficiency of the power generation system with respect to the operational impedance of the load.