Capacitor charger system and digital control module and isolated acquisition module for such a capacitor charger system

• US 8,797,001 B2
• Filed: 06/30/2009
• Issued: 08/05/2014
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Scandinova Systems AB
• Original Assignee: Scandinova Systems AB
• Inventors: Elmqvist, Klas, Hartman, Carl, Graas, Magnus, Gustafsson, Jonas, Lundgren, Jan, Crewson, Walter Frederick John, Wickstrm, Andreas
• Primary Examiner(s): Fantu, Yalkew
• Application Number:
  US13/378,795
• Publication Number:
  US 20120086410A1
• Time in Patent Office: 1,862 Days
• Field of Search: 320/166, 320/106, 307/109, 363/59, 363/74
• US Class Current: 320/166
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H03K 3/53 by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback H03K3/335 takes precedence

Abstract

The invention relates to a capacitor charger system (100) comprising a capacitor charger module (110), an isolated acquisition module (120), and a digital control module (130). The isolated acquisition module (120) is configured for sampling an output voltage level of said capacitor charger module (110). The digital control module (130) is connected to the isolated acquisition module (120) via a bi-directional link and connected to the capacitor charger module (110) via a control signal interface. The digital control module (130) is configured for generating control signal information and synchronization signal information based on data representative of sampled output voltage levels received via the bi-directional link from the isolated acquisition module. The digital control module (130) is further configured for sending the control signal information to the capacitor charger module (110) via the control signal interface and for sending the synchronization signal information to the isolated acquisition module (120) via the bidirectional link. The capacitor charger module (110) is controlled based on the control signal information from the digital control module, and the isolated acquisition module (120) is configured for performing sampling based on the synchronization signal information.

Claims

1. A capacitor charger system comprising:

a capacitor charger module;

an isolated acquisition module for sampling an output voltage level of said capacitor charger module;

a digital control module, connected to said isolated acquisition module via a bidirectional link and connected to said capacitor charger module via a control signal interface, for generating control signal information and synchronization signal information based on data representative of sampled output voltage levels received via said bidirectional link from said isolated acquisition module, and for sending said control signal information to said capacitor charger module via said control signal interface and for sending said synchronization signal information to said isolated acquisition module via said bi-directional link,

wherein said capacitor charger module is controlled based on said control signal information from said digital control module; and

wherein said isolated acquisition module is configured for performing said sampling based on said synchronization signal information.

2. The capacitor charger system of claim 1, wherein said isolated acquisition module is configured for performing said sampling based on said synchronization signal information at a controlled timing relation to the output pulses of said capacitor charger module.

3. The capacitor charger system of claim 2, wherein said capacitor charger module is a Pulse Width Modulated (PWM) capacitor charger module, and said digital control module is configured for generating said control signal information in the form of a PWM control pattern including PWM control pulses, wherein said isolated acquisition module is configured for performing sampling of an output voltage level of said capacitor charger module in close relation before a next PWM control pulse so that distortions in the output voltage of said capacitor charger module from a previous output pulse have faded down to an acceptable level.

4. The capacitor charger system of claim 2, wherein the output pulse frequency of said capacitor charger module is higher than 10 KHz, and preferably in the order of 25 kHz or higher, and the sampling frequency is at least as high as said output pulse frequency.

5. The capacitor charger system of claim 4, wherein the sampling frequency is higher than 50 kHz, and preferably in the order of 1 MHz or higher.

6. The capacitor charger system of claim 1, wherein said isolated acquisition module is configured for performing sampling isolated from common ground.

7. The capacitor charger system of claim 1, wherein said bi-directional link is a digital optical link, and said isolated acquisition module and said digital control module each includes an optical input/output interface.

8. The capacitor charger system of claim 1, wherein said isolated acquisition module includes a signal acquisition circuit connected to an analog-to-digital converter (ADC)₁ which in turn is connected to a first digital signal processing module, wherein the sampling of said ADC is controlled based on said synchronization signal information.

9. The capacitor charger system of claim 8, wherein said first digital processing module is implemented in a Field Programmable Gate Array (FPGA)₁ an Application Specific Integrated Circuit (ASIC) or a Digital Signal Processor (DSP).

10. The capacitor charger system of claim 1, wherein said digital control module includes a second digital processing module configured for generating control data based on said sampled signal levels received from said isolated acquisition module and a predetermined reference signal level, wherein said digital control module is configured for generating said control signal information based on said control data.

11. The capacitor charger system of claim 10, wherein said capacitor charger module is a Pulse Width Modulated (PWM) capacitor charger module, and said digital control module further includes a driver circuit connected to said second digital processing module for generating said control signal information in the form of a PWM control pattern based on said control data.

12. The capacitor charger system of claim 10, wherein said second digital processing module is implemented in a Field Programmable Gate Array (FPGA)₁ an Application Specific Integrated Circuit (ASIC) or a Digital Signal Processor (DSP).

13. The capacitor charger system of claim 1, wherein the output pulses of said capacitor charger module have a voltage higher than 500 V but lower than 2500 V, and preferably between 900 and 1500 V.

14. A power modulator comprising a capacitor charger system of claim 1.

15. A digital control module for a capacitor charger system, wherein said capacitor charger system has a capacitor charger module and an isolated acquisition module for sampling an output voltage level of said capacitor charger module,

wherein said digital control module is connected to said isolated acquisition module via a bi-directional link and connected to said capacitor charger module via a control signal interface,

wherein said digital control module is configured for generating control signal information and synchronization signal information based on data representative of sampled output voltage levels of said capacitor charger module received via said bidirectional link from said isolated acquisition module,

wherein said digital control module is configured for sending said control signal information to said capacitor charger module via said control signal interface to control the output pulses of the capacitor charger module, and for sending said synchronization signal information to said isolated acquisition module via said bi-directional link to control the sampling operation of said isolated acquisition module.

16. The digital control module of claim 15, wherein said digital control module is configured for generating said synchronization signal information such that said sampling by said isolated acquisition module is performed at a controlled timing relation to the output pulses of said capacitor charger module.

17. The digital control module of claim 16, wherein said digital control module is configured for generating said control signal information in the form of a Pulse Width Modulated (PWM) control pattern including PWM control pulses, and configured for generating said synchronization signal information such that sampling of an output voltage level of said capacitor charger module is performed in close relation before a next PWM control pulse so that distortions in the output voltage of said capacitor charger module from a previous output pulse have faded down to an acceptable level.

18. An isolated acquisition module for a capacitor charger system, wherein said capacitor charger system has a capacitor charger module and a digital control module,

wherein said isolated acquisition module is connected to said digital control module via a bi-directional link, and

wherein said isolated acquisition module is configured for sampling an output voltage level of said capacitor charger module at a controlled timing relation to the output pulses of said capacitor charger module based on synchronization signal information from said digital control module.

19. The isolated acquisition module of claim 18, wherein said capacitor charger module is a Pulse Width Modulated (PWM) capacitor charger module for operation under the control of PWM control pulses, wherein said isolated acquisition module is configured for performing sampling of an output voltage level of said capacitor charger module in close relation before a next PWM control pulse so that distortions in the output voltage of said capacitor charger module from a previous output pulse have faded down to an acceptable level.