System and method for regulating resonant inverters

• US 20050265058A1
• Filed: 05/25/2004
• Published: 12/01/2005
• Est. Priority Date: 05/25/2004
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Stevanovic, Ljubisa Dragoljub, Zane, Regan Andrew
• Granted Patent: US 7,262,981 B2
• Time in Patent Office: Days
• US Class Current: 363/131
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A technique is provided for direct digital phase control of resonant inverters based on sensing of one or more parameters of the resonant inverter. The resonant inverter control system includes a switching circuit for applying power signals to the resonant inverter and a sensor for sensing one or more parameters of the resonant inverter. The one or more parameters are representative of a phase angle. The resonant inverter control system also includes a comparator for comparing the one or more parameters to a reference value and a digital controller for determining timing of the one or more parameters and for regulating operation of the switching circuit based upon the timing of the one or more parameters.

Claims

1. A resonant inverter control system comprising:

a switching circuit for applying power signals to a resonant inverter;

a sensor for sensing one or more parameters of the resonant inverter, the one or more parameters being representative of a phase angle;

a comparator for comparing the one or more parameters to a reference value;

a digital controller for determining timing of the one or more parameters and for regulating operation of the switching circuit based upon the timing of the one or more parameters.

2. The resonant inverter control system of claim 1, wherein the one or more parameters comprise at least one of inductor voltage, inductor current, load voltage, and load current.

3. The resonant inverter control system of claim 1, wherein the sensor comprises at least one of a current sensor and a voltage sensor.

4. The resonant inverter control system of claim 1, wherein the reference value is a ground value.

5. The resonant inverter control system of claim 1, further comprising a regulating circuit adapted to provide a phase command representative of a desired phase angle.

6. The resonant inverter control system of claim 5, wherein the phase command is in a range of 0 degree to 90 degrees.

7. The resonant inverter control system of claim 1, wherein the timing of the one or more parameters comprises at least one of switching time, delay time, and duty time.

8. The resonant inverter control system of claim 7, wherein the switching time is the time between two consecutive rising edges at zero-crossings of the one or more parameters.

9. The resonant inverter control system of claim 7, wherein the delay time and the duty time are dependent on the switching time.

10. The resonant inverter control system of claim 1, wherein the comparator and the digital controller is selected based upon control speed.

11. A method for regulating a resonant inverter, the method comprising:

sensing one or more parameters of the resonant inverter, the one or more parameters being representative of a phase angle;

comparing the one or more parameters to a reference value;

determining timing of the one or more parameters; and

regulating the resonant inverter via a switching circuit based upon the timing of the one or more parameters.

12. The method of claim 11, wherein the one or more parameters comprises at least one of inductor voltage, inductor current, load voltage, and load current.

13. The method of claim 11, wherein the timing of the one or more parameters comprises at least one of switching time, delay time, and duty time.

14. A method for regulating a resonant inverter, the method comprising:

detecting zero-crossings of an inductor voltage;

recording a time interval between two zero-crossings;

determining a delay time and a duty time from the zero-crossings; and

regulating the resonant inverter via a switching circuit based upon the delay time and the duty time.

15. The method of claim 14, further comprising turning off a low side gate and turning on a high side gate of the switching circuit via a gate driver after a time interval substantially equivalent to the delay time.

16. The method of claim 14, further comprising turning off a high side gate and turning on a low side gate of the switching circuit via a gate driver after a time interval substantially equivalent to the duty time.

17. A method for regulating a resonant inverter, the method comprising:

detecting zero-crossings of an inductor current;

recording a time interval between two zero-crossings;

determining a delay time from the zero-crossings; and

regulating the resonant inverter via a switching circuit based upon the delay time.

18. The method of claim 17, further comprising turning off a high side gate and turning on a low side gate of the switching circuit via a gate driver after a time interval substantially equivalent to the delay time.

19. The method of claim 17, further comprising turning off a low side gate and turning on a high side gate of the switching circuit via a gate driver after a time interval substantially equivalent to half the switching time.

20. A tangible, machine readable media, comprising:

code adapted to sense one or more parameters of a resonant inverter, the one or more parameters being representative of a phase angle;

code adapted to compare the one or more parameters to a reference value;

code adapted to determine timing of the one or more parameters; and

code adapted to regulate the resonant inverter via a switching circuit based upon the timing of the one or more parameters.