Power converter having integrated capacitor-blocked transistor cells

Patent metadata

Field	Value
Publication number	US-9525348-B1
Application number	US-201514814914-A
Country	US
Kind code	B1
Filing date	Jul 31, 2015
Priority date	Jul 31, 2015
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A converter for connecting a voltage source to a load includes a plurality of ICBT (integrated capacitor blocked transistor) cells configured as switches and connected in series to form a series connection path, a main capacitor connected across the series connection path, and a controller. Each ICBT cell includes a main transistor disposed in the series connection path and a series connected auxiliary transistor and auxiliary capacitor coupled in parallel with the main transistor. The controller is operable to develop a voltage across the main capacitor which exceeds a voltage rating of the ICBT cells, by switching the ICBT cells so as to commutate current within the individual ICBT cells without the ICBT cells providing active power to the load so that power flow is from the voltage source, to the main capacitor, to the load and not through the auxiliary transistors and the auxiliary capacitors.

First claim

What is claimed is:

1. A converter for connecting a voltage source to a load, the converter comprising:
a plurality of ICBT (integrated capacitor blocked transistor) cells configured as switches and connected in series to form a series connection path, each ICBT cell comprising a main transistor disposed in the series connection path and a series connected auxiliary transistor and auxiliary capacitor coupled in parallel with the main transistor;
a main capacitor connected across the series connection path, the main capacitor having a greater energy-power ratio as expressed in J/kVA than the auxiliary capacitors of the ICBT cells; and
a controller operable to develop a voltage across the main capacitor which exceeds a voltage rating of the ICBT cells, by switching the ICBT cells so as to commutate current within the individual ICBT cells without the ICBT cells providing active power to the load so that power flow is from the voltage source, to the main capacitor, to the load and not through the auxiliary transistors and the auxiliary capacitors.

2. The converter of claim 1 , wherein the controller is operable to switch the main transistor and the auxiliary transistor of each ICBT cell in a complementary way with a first dead time between turning off one of the main transistors of each ICBT cell and turning on the auxiliary transistor within the same ICBT cell and with a second dead time between turning-off the main transistors of an arm carrying current and turning-on the main transistors of the same arm or an arm where the current is to commute.

3. The converter of claim 2 , wherein the first dead time is larger than the second dead time.

4. The converter of claim 1 , wherein each ICBT cell comprises a first diode in parallel with the auxiliary transistor of that ICBT cell, and wherein the auxiliary capacitor of each ICBT cell is charged through the first diode of that ICBT cell and remains fully charged with at most slight perturbations during switching of that ICBT cell.

5. The converter of claim 4 , wherein a voltage of the auxiliary capacitor of each ICBT cell is imposed on the main transistor of that ICBT cell when the auxiliary transistor is closed so as to ensure voltage balance across the ICBT cells without the controller having to provide voltage balancing control for the ICBT cells.

6. The converter of claim 1 , wherein the auxiliary capacitors of the ICBT cells have an aggregated size less than 1 J/kVA.

7. The converter of claim 1 , wherein the auxiliary transistor and the main transistor of each ICBT cell have the same voltage rating and the auxiliary transistor has a current rating not larger than ⅓ of the main transistor.

8. The converter of claim 1 , wherein the auxiliary transistor and the main transistor of each ICBT cell are IGBTs (insulated gate bipolar transistors).

9. The converter of claim 1 , wherein the auxiliary transistor and the main transistor of each ICBT cell are power MOSFETs (metal oxide semiconductor field effect transistors).

10. The converter of claim 1 , wherein the auxiliary transistor and the main transistor of each ICBT cell are GaN transistors.

11. The converter of claim 1 , wherein the auxiliary transistor and the main transistor of each ICBT cell are SiC transistors or a combination Si and SiC.

12. The converter of claim 1 , wherein:
the converter is a buck DC-DC converter;
one or more first ones of the ICBT cells are electrically connected between a first terminal of the voltage source and a first terminal of an inductor;
a second terminal of the inductor is electrically connected to a first terminal of the main capacitor;
a second terminal of the main capacitor is electrically connected to a second terminal of the voltage source; and
one or more second ones of the ICBT cells are electrically connected between the first terminal of the inductor and the second terminal of the capacitor.

13. The converter of claim 12 , wherein:
at least two first ones of the ICBT cells are electrically connected between the first terminal of the voltage source and the first terminal of the inductor;
at least two second ones of the ICBT cells are electrically connected between the first terminal of the inductor and the second terminal of the capacitor; and
the controller operates open-loop without voltage balancing control for the ICBT cells.

14. The converter of claim 1 , wherein:
the converter is a H-bridge voltage DC voltage source inverter having a first output terminal and a second output terminal;
one or more first ones of the ICBT cells are electrically connected between a first terminal of the main capacitor and the first output terminal and one or more second ones of the ICBT cells are electrically connected between the first output terminal and a second terminal of the main capacitor to form a first phase of the H-bridge voltage DC voltage source inverter; and
one or more third ones of the ICBT cells are electrically connected between the first terminal of the main capacitor and the second output terminal and one or more fourth ones of the ICBT cells are electrically connected between the second output terminal and the second terminal of the main capacitor to form a second phase of the H-bridge voltage DC voltage source inverter.

15. The converter of claim 14 , wherein:
at least two first ones of the ICBT cells are connected in series to form a first phase arm of the first phase;
at least two second ones of the ICBT cells are connected in series to form a second phase arm of the first phase;
at least two third ones of the ICBT cells are connected in series to form a first phase arm of the second phase;
at least two fourth ones of the ICBT cells are connected in series to form a second phase arm of the second phase; and
the controller operates open-loop without voltage balancing control for the ICBT cells.

16. The converter of claim 1 , wherein the controller is operable to switch the ICBT cells using open-loop control without providing voltage balancing control for the ICBT cells.

17. A method of voltage conversion between a voltage source and a load, the method comprising:
connecting a plurality of ICBT (integrated capacitor blocked transistor) cells configured as switches in series to form a series connection path, each ICBT cell comprising a main transistor disposed in the series connection path and a series connected auxiliary transistor and auxiliary capacitor coupled in parallel with the main transistor;
connecting a main capacitor across the series connection path, the main capacitor having a greater energy-power ratio as expressed in J/kVA than the auxiliary capacitors of the ICBT cells; and
developing a voltage across the main capacitor which exceeds a voltage rating of the ICBT cells, by switching the ICBT cells so as to commutate current within the individual ICBT cells without the ICBT cells providing active power to the load so that power flow is from the voltage source, to the main capacitor, to the load and not through the auxiliary transistors and the auxiliary capacitors.

18. The method of claim 17 , wherein switching the ICBT cells so as to commutate current within the individual ICBT cells without the ICBT cells providing active power to the load comprises:
switching the main transistor and the auxiliary transistor of each ICBT cell in a complementary way with a first dead time between turning off one of the main transistors of each ICBT cell and turning on the auxiliary transistor within the same ICBT cell and with a second dead time between turning-off the main transistors of an arm

Assignees

• Abb Technology Ag
• Abb Schweiz Ag

Inventors

• Aeloiza Eddy
• Canales Francisco
• Burgos Rolando

Classifications

• H02M3/158 Primary

  including plural semiconductor devices as final control devices for a single load · CPC title

• H02M7/4835

  comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage · CPC title

• H02M7/48

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title