SOFT-SWITCHING HIGH VOLTAGE POWER CONVERTER

• US 20140049990A1
• Filed: 04/08/2013
• Published: 02/20/2014
• Est. Priority Date: 08/14/2012
• Status: Active Grant

• Current Assignee: Rudolf Limpaecher
• Original Assignee: Rudolf Limpaecher
• Inventors: Limpaecher, Rudolf
• Granted Patent: US 8,824,179 B2
• Time in Patent Office: Days
• US Class Current: 363/15
• CPC Class Codes: H02J 3/36 Arrangements for transfer of electric power between ac networks via a high-tension dc link
• 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 1/0074 Plural converter units whose inputs are connected in series
• CPC Class Codes: H02M 1/0077 Plural converter units whose outputs are connected in series
• CPC Class Codes: H02M 3/24 by static converters
• CPC Class Codes: H02M 3/33584 Bidirectional converters
• 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
• CPC Class Codes: Y02E 60/60 Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Abstract

In a general aspect, a charge transfer includes a transformer including a plurality of primary windings and a plurality of galvanically isolated secondary windings, a first plurality of resonant converters having input terminals connected in series to an input power terminal and having output terminals connected to different primary windings of the plurality of primary windings, a second plurality of resonant converters having input terminals connected to different secondary windings of the plurality of secondary windings and having output terminals connected to a galvanically isolated power terminal, and a control system for controlling a transfer of electric charge between the input power terminal and the galvanically isolated output power terminal including controlling a first plurality of switches of the first plurality of resonant converters and a second plurality of switches of the second plurality of resonant converters in a zero current soft switching mode.

Claims

1. A charge transfer apparatus for transferring an electric charge between an input power terminal and a galvanically isolated output power terminal comprising:

a transformer including a plurality of primary windings and a plurality of galvanically isolated secondary windings;

a first plurality of resonant converters having input terminals connected in series to the input power terminal and having output terminals connected to different primary windings of the plurality of primary windings;

a second plurality of resonant converters having input terminals connected to different secondary windings of the plurality of secondary windings and having output terminals connected to the galvanically isolated power terminal;

a control system for controlling the transfer of electric charge between the input power terminal and the galvanically isolated output power terminal including controlling a first plurality of switches of the first plurality of resonant converters and a second plurality of switches of the second plurality of resonant converters in a zero current soft switching mode.

2. The apparatus of claim 1 wherein the input terminal is configured to receive voltages in the range of 600V to 1000 kV.

3. The apparatus of claim 1 wherein the control system controls the first and second plurality of switches according to a predefined switching sequence.

4. The apparatus of claim 1 wherein the transformer is a high frequency transformer operable at frequencies up to 50 kHz.

5. The apparatus of claim 1 further comprising a plurality of transformers, each including a plurality of primary windings and a plurality of galvanically isolated secondary windings.

6. The apparatus of claim 1 further configured for transferring charge bidirectionally between the input terminal and the galvanically isolated output power terminal.

7. The apparatus of claim 1 wherein the output terminals of the second plurality of resonant converters are connected in series to the galvanically isolated output power terminal.

8. The apparatus of claim 1 wherein the input power terminal is a DC power terminal and the galvanically isolated output power terminal is a DC power terminal.

9. The apparatus of claim 1 wherein the input power terminal is a DC power terminal and the galvanically isolated output power terminal is an AC power terminal.

10. The apparatus of claim 1 wherein the input power terminal is an AC power terminal and the galvanically isolated output power terminal is a DC power terminal.

11. The apparatus of claim 1 wherein the input power terminal is an AC power terminal and the galvanically isolated output power terminal is an AC power terminal.

12. An n phase charge transfer apparatus including:

n charge transfer apparatuses connected to an AC grid, each charge transfer apparatus of the n charge transfer apparatuses including;

a transformer including a plurality of primary windings and a plurality of galvanically isolated secondary windings;

a first plurality of resonant converters having input terminals connected in series to the input power terminal and having output terminals connected to different primary windings of the plurality of primary windings;

a second plurality of resonant converters having input terminals connected to different secondary windings of the plurality of secondary windings and having output terminals connected to the galvanically isolated power terminal;

a control system for controlling the transfer of electric charge between the input power terminal and the galvanically isolated output power terminal including controlling a first plurality of switches of the first plurality of resonant converters and a second plurality of switches of the second plurality of resonant converters in a zero current soft switching mode;

wherein a smallest difference in phase angle of operation between the n charge transfer apparatuses is 360 degrees/n and the control systems of each of the n charge transfer apparatuses are configured to coordinate the n charge transfer apparatuses to operate as an n phase charge transfer apparatus.

13. The n phase charge transfer apparatus of claim 12 wherein n equals three, the three phase charge transfer apparatus is connected to the AC grid in a parallel DELTA configuration, and the control systems of the three charge transfer apparatuses are configured to operate the three charge transfer apparatuses as a three phase AC to AC transformer.

14. The n phase charge transfer apparatus of claim 12 wherein n equals 3 and the n phase charge transfer apparatus is connected to the AC grid in a rotating open DELTA configuration.

15. The n phase charge transfer apparatus of claim 12 wherein the input terminals of each of the first and second pluralities of resonant converters are AC terminals and the galvanically isolated output power terminals of each of the first and second pluralities of resonant converters are DC terminals.

16. The n phase charge transfer apparatus of claim 12 wherein the input terminals of each of the first and second pluralities of resonant converters are DC terminals and the galvanically isolated output power terminals of each of the first and second pluralities of resonant converters are AC terminals.

17. The n phase charge transfer apparatus of claim 12 wherein the control system is configured to operate the system as a VAR compensator.