Method and system for active resonant voltage switching

• US 8,861,681 B2
• Filed: 12/17/2010
• Issued: 10/14/2014
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Caiafa, Antonio, Edic, Peter Michael, Wilson, Colin Richard
• Primary Examiner(s): Ho, Allen C.
• Application Number:
  US12/972,156
• Publication Number:
  US 20120155613A1
• Time in Patent Office: 1,397 Days
• Field of Search: 378/91, 378/98.9, 378/98.11, 378/101, 378/103, 378/104, 378/105, 378/111, 378/112, 378/114, 378/115, 378/5, 378/16
• US Class Current: 378/112
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/33573 Full-bridge at primary side of an isolation transformer
• CPC Class Codes: H02M 7/10 arranged for operation in series, e.g. for multiplication of voltage
• CPC Class Codes: H05G 1/10 Power supply arrangements for feeding the X-ray tube supply circuits with converters in general H02M; supply circuits for emitters and amplifiers H04B1/16 - H04B1/1623
• 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

Methods and systems for active resonant voltage switching are provided. One active resonant switching system includes a voltage switching system having one or more active resonant modules to provide a switching voltage output. Each of the resonant modules includes a plurality of switching devices configured to operate in open and closed states to produce first and second voltage level outputs from a voltage input. The resonant modules also include a capacitor connected to the switching devices and configured to receive a discharge energy during a resonant operating cycle when switching an output voltage from the first voltage level to the second voltage level, wherein the capacitor is further configured to restore system energy when switching from the second to first voltage level. The resonant modules further include a resonant inductor configured to transfer energy to and from the capacitor.

Claims

1. A voltage switching system comprising:

a plurality of active resonant modules connected to provide a switching voltage output, the plurality of active resonant modules defining a plurality of switching stages, each active resonant module of the plurality of active resonant modules including;

a plurality of switching devices configured to operate in open and closed states to produce first and second voltage levels as outputs from a voltage input;

first and second capacitors connected to the plurality of switching devices, the first capacitor configured to receive a system discharge energy from the second capacitor during a resonant operating cycle when switching an output voltage from the first voltage level to the second voltage level, wherein the first capacitor is further configured to restore system energy to the second capacitor when switching from the second voltage level to the first voltage level; and

a resonant inductor connected in series between the first and second capacitors, the resonant inductor configured to transfer energy to and from the first and second capacitors.

2. The voltage switching system of claim 1, further comprising an x-ray tube connected to an output of the one or more active resonant modules and configured to provide two different energy spectra when powered by the first and second voltage levels.

3. The voltage switching system of claim 1, wherein the plurality of switching devices are connected in an anti-parallel configuration.

4. The voltage switching system of claim 1, wherein the resonant inductor is connected in series with the capacitor and configured to control a switching speed of the voltage level outputs.

5. The voltage switching system of claim 1, wherein the plurality of switching devices comprise transistors.

6. The voltage switching system of claim 1, wherein the first voltage level is higher than the second voltage level.

7. The voltage switching system of claim 1, wherein the plurality of switching devices is configured to recirculate the system energy stored in the capacitor during a next resonant operating cycle to switch an output voltage from the second voltage level to the first voltage level.

8. The voltage switching system of claim 1, further comprising an additional switching device and diode, wherein the additional switching device is connected in series with the switching devices and two of the switching devices are configured to be in a same state, which is different than a state of the other switching device.

9. The voltage switching system of claim 1, further comprising a power transformer and wherein the plurality of switching devices are connected to secondary windings of the power transformer.

10. The voltage switching system of claim 9, wherein the transformer comprises two primary windings.

11. The voltage switching system of claim 10, further comprising a single inverter connected to the two primary windings.

12. A high voltage generator system comprising:

a voltage source; and

an active resonant circuit connected to the voltage source, the active resonant circuit including a plurality of resonant switching modules configured to output two different voltage levels using resonant switching of a plurality of switching devices in each resonant switching module of the plurality of resonant switching modules, wherein discharged energy is stored and reused during resonant switching cycles, and the plurality of resonant switching modules being rechargeable to operate at the two different voltage levels.

13. The high voltage generator system of claim 12, further comprising an x-ray tube connected to an output of the active resonant circuit and configured to provide two different energy levels when powered by the two different voltage levels.

14. The high voltage generator system of claim 13, wherein the active resonant circuit is integrated with the x-ray tube.

15. The high voltage generator system of claim 13, wherein the active resonant circuit comprises switching devices configured to switch an output between the voltage levels, wherein a switching time for the switching is about 10-100 microseconds or less and further comprising an inductor connected in series with the switching devices to control the switching time.

16. The high voltage generator system of claim 12, further comprising an active resonant interposer circuit and wherein each of the plurality of resonant switching modules comprises a capacitor and the active resonant interposer circuit is configured for active operation such that the capacitor of each of the plurality of resonant switching modules is rechargeable at one or both of a high voltage level and a low voltage level.

17. The high voltage generator system of claim 12, wherein the active resonant circuit is a separate unit being an interposer circuit, the interposer circuit being separate from and coupled to the voltage source.

18. The high voltage generator system of claim 12, wherein the active resonant circuit is integrated with the voltage source.

19. A method for controlling voltage switching, the method comprising:

configuring a plurality of active resonant modules to use a plurality of switching devices in each of the active resonant modules of the plurality of active resonant modules to switch between states during resonance operation;

providing first and second capacitors to store discharged energy during a resonant cycle of the resonance operation and being rechargeable in each of the states, wherein the first capacitor is configured to receive a system discharge energy from the second capacitor during a resonant cycle when switching an output voltage from a first voltage level to a second voltage level, the first capacitor further configured to restore system energy to the second capacitor when switching from the second voltage level to the first voltage level; and

providing a resonant inductor connected in series between the first and the second capacitors, the resonant inductor configured to transfer energy to and from the first and the second capacitors.

20. The method of claim 19, further comprising configuring the plurality of switching devices to recirculate the stored energy during another resonant cycle of the resonance operation.