Very high frequency switching resonant synchronous rectification
A VHF switching power converter comprising one or more VHF switching frequency resonant synchronous rectifiers receives an output from an inverter and delivers a DC output to a load. The power converter includes a controller for controlling at least one of the one or more VHF switching frequency resonant synchronous rectifiers based on feedback derived from a waveform of at least one of the rectifiers. The controller controls a phase angle of at least one of the rectifiers with a delay locked loop. The power converter delivers a regulated DC output via adjustment of a phase shift between at least one of the one or more rectifiers and the inverter.
1. A power converter having a switching frequency of at least 30 MHz, the power converter comprising:
an inverter stage for receiving an input and generating an inverter output, wherein the inverter stage comprises an inverter switch configured to switch the inverter stage;
a synchronous rectifier stage for receiving the inverter output and for delivering an output of the power converter to a load, wherein the synchronous rectifier stage comprises a synchronous rectifier switch configured to switch the synchronous rectifier stage; and
a controller configured to control the output of the power converter by modulating the at least one of the inverter stage and synchronous rectifier stage on and off at a frequency less than a switching frequency of at least one of the inverter stage and the synchronous rectifier stage, the controller being further configured to adjust, independently of an amount of power delivered to the load, one or more of a duty cycle of the inverter switch, a duty cycle of the synchronous rectifier switch, and a phase between the switching of the inverter switch and the switching of the synchronous rectifier switch.
2. The power converter of claim 1 , wherein the controller is further configured to control switching of at least one of the inverter switch and the synchronous rectifier switch based on at least one of an efficiency of the power converter and achieving a chosen waveform shape.
3. The power converter of claim 1 , wherein the controller is further configured to use feedback combined with the modulating to control at least one of an input of the inverter and an output power provided by the output of the power converter.
4. The power converter of claim 2 , wherein the controller is further configured to switch the at least one of the inverter switch and the synchronous rectifier switch independently of control of the output of the power converter.
5. The power converter of claim 1 , wherein the controller is further configured to control the output of the power converter by modulating the power converter on and off at a frequency less than a switching frequency of at least one of the inverter stage and the synchronous rectifier stage, wherein the power converter is configured to control one or more of the duty cycle of the inverter switch, the duty cycle of the synchronous rectifier switch, and the phase between the switching of the inverter switch and the synchronous rectifier switch based on an efficiency of the power converter and/or based on achieving a chosen waveform shape.
6. The power converter of claim 1 , wherein the controller is further configured to control the switching of the at least one of the inverter switch and the synchronous rectifier switch by at least one switching function parameter that is based on at least one of the following port parameters:
an inverter port voltage,
an inverter port current,
a synchronous rectifier port voltage, and
a synchronous rectifier port current.
7. The power converter of claim 1 , wherein the inverter switch is controlled as a function of at least one of the following:
an inverter port voltage,
an inverter port current,
a synchronous rectifier port voltage, and
a synchronous rectifier port current.
8. The power converter of claim 1 , wherein the synchronous rectifier switch is controlled as a function of at least one of the following:
an inverter port voltage,
an inverter port current,
a synchronous rectifier port voltage, and
a synchronous rectifier port current.
9. The power converter of claim 1 , wherein a the inverter switch is controlled as a function of an average of at least one of the following:
an inverter port voltage,
an inverter port current,
a synchronous rectifier port voltage, and
a synchronous rectifier port current.
10. The power converter of claim 1 , wherein the synchronous rectifier switch is controlled as a function of an average of at least one of the following:
an inverter port voltage,
an inverter port current,
a synchronous rectifier port voltage, and
a synchronous rectifier port current.
11. The power converter of claim 1 , wherein the controller is configured to control switching of at least one of the inverter switch and the synchronous rectifier switch based on parameters of an inverter port and a synchronous rectifier port.
12. The power converter of claim 1 , wherein the controller is configured to control switching of at least one of the inverter switch and the synchronous rectifier switch to achieve zero-voltage switching (ZVS) or near-ZVS.
13. The power converter of claim 1 ,
wherein the power converter comprises a plurality of power converter cells;
wherein the power converter cells are connected in at least one of series and parallel to provide a combined power converter output for delivery to the load,
wherein the inverter stage comprises an inverter stage of at least one of the power converter cells; and
wherein the synchronous rectifier stage comprises a synchronous rectifier stage of at least one of the power converter cells.
14. The power converter of claim 1 , further comprising a connection between the inverter stage and the synchronous rectifier stage, wherein the connection comprises at least one of the following:
a transformer,
a resonant transformer,
a transmission line transformer,
a wide-band transformer, and
a passive transformation network.
15. The power converter of claim 14 , wherein the connection comprises at least one of the following passive transformation networks:
an L-section passive transformation network, and
a Pi-section passive transformation network.
16. The power converter of claim 1 , wherein the inverter stage is configured as at least one of the following inverter classes: Class-Φ2, and Class-E.
17. The power converter of claim 1 , wherein the synchronous rectifier is configured as at least one of the following synchronous rectifier classes: Class-Φ2, and Class-E.
18. The power converter of claim 1 , wherein the controller is configured to control at least one of a phase and a duty ratio of the one or more of the inverter switch and the synchronous rectifier switch using a transfer function that is based on at least one of the following:
a closed-form mathematical solution,
a numerical simulation, and
direct measurement.
19. The power converter of claim 1 , wherein the inverter stage is configured to receive a substantially DC input.
20. The power converter of claim 1 , wherein the synchronous rectifier stage is configured to deliver to the load a substantially DC output.
21. The power converter of claim 1 , wherein the controller is configured to control, independently of an amount of power delivered to the load, the duty cycle of the inverter switch.
22. The power converter of claim 1 , wherein the controller is configured to control, independently of an amount of power delivered to the load, the duty cycle of the synchronous rectifier switch.
23. The power converter of claim 1 , wherein the controller is configured to control, independently of an amount of power delivered to the load, the phase between the switching of the inverter switch and the switching of the synchronous rectifier switch.
24. The power converter of claim 1 , wherein the controller is further configured to:
choose a level of converter performance, wherein the chosen level of converter performance comprises at least one of a chosen level of efficiency and a chosen waveform shape; and
implement at least one transfer function that will result in the chosen level of performance, wherein the at least one transfer function comprises a function of at least one of an inverter stage input voltage and a synchronous rectifier stage output voltage, and wherein the implementing comprises
measuring the at least one of inverter stage input voltage and synchronous rectifier stage output voltage,
applying the measured at least one of inverter stage input voltage and measured synchronous rectifier stage output voltage to the at least one transfer function, and
adjusting switching parameters of at least one of the inverter switch and the synchronous rectifier switch based on the applied at least one transfer function.
25. The power converter of claim 24 ,
wherein the at least one transfer function comprises at least one of the following:
a first transfer function for a duty cycle for the inverter switch,
a second transfer function for a duty cycle for the synchronous rectifier switch, and
a third transfer function for a phase shift between the inverter stage and the synchronous rectifier stage; and
wherein the implementing further comprises adjusting at least one of the duty cycle for the inverter switch, the duty cycle for the synchronous rectifier switch, and the phase shift between the inverter stage and the synchronous rectifier based on the applied at least one transfer function.
26. The power converter of claim 25 , wherein the controller is further configured to control the switching of the at least one of the inverter switch and the synchronous rectifier switch by at least one switching function parameter that is based on at least one of the following port parameters:
an inverter port voltage, an
inverter port current,
a synchronous rectifier port voltage, and a
synchronous rectifier port current.
27. The power converter of claim 24 , wherein the at least one transfer function is based on at least one of the following:
a closed-form mathematical solution,
a numerical simulation, and
direct measurement.
28. The power converter of claim 1 , wherein the controller is configured to control an input of the power converter by modulating at least one of the inverter stage and synchronous rectifier stage on and off at the frequency less than the switching frequency of at least one of the inverter stage and the synchronous rectifier stage.
29. The power converter of claim 1 , wherein the power converter has a switching frequency in a very high frequency (VHF) range.