Converter device and uninterruptible power supply equipped with such a device

• US 20110193412A1
• Filed: 01/19/2011
• Published: 08/11/2011
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• Current Assignee: Mge Ups
• Original Assignee: Mge Ups
• Inventors: Lacarnoy, Alain
• Granted Patent: US 8,598,749 B2
• Time in Patent Office: Days
• US Class Current: 307/75
• CPC Class Codes: H02M 1/0095 Hybrid converter topologies, e.g. NPC mixed with flying capacitor, thyristor converter mixed with MMC or charge pump mixed with buck
• CPC Class Codes: H02M 7/483 Converters with outputs that each can have more than two voltages levels
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters

Abstract

A converter to supply an AC voltage on a modulated signal output comprising two switching units each provided with a DC voltage input and a switching output to supply pulses varying between the voltage on the input in a first switched state, and a reference voltage in a second switched state, each switching unit comprising a first switch connected between the input and the switching output to establish said first switched state, said device comprising, for each switching unit, a second switch connected between said switching output and said modulated signal output to activate said switching unit, and a third switch connected between the input of said switching unit and the modulated signal output.

An uninterruptible power supply provided with this converter.

Claims

1. A converter device enabling an AC voltage and current to be supplied by filtering pulses obtained on a modulated signal output from three substantially DC voltages available on a reference voltage line and on two DC voltage inputs of opposite signs respectively from two switching units,

each switching unit comprising a switching output to supply pulses having an amplitude varying between the voltage on the input of said switching unit, in a first switched state of said switching unit, and the voltage on said reference voltage line, in a second switched state of said switching unit,

each switching unit comprising a first switch connected between the input and the switching output of said switching unit to establish said first switched state by closing of said first switch,

said device comprising, for each switching unit, a second switch associated with said switching unit, connected between said switching unit and said modulated signal output to activate said switching unit by closing of said second switch,

wherein, for each switching unit, said device comprises a third switch connected between the input of said switching unit and the modulated signal output, said first switch being controlled in such a way as to switch from the first switched state to the second switched state, in one direction or the other, keeping said third switch open, said third switch being controlled to be closed during at least a part of the duration of said first switched state.

2. The device according to the claim 1, wherein each switching unit further comprises a diode connected between the reference voltage line and the switching output of said switching unit to establish the second switched state when the first switch is open.

5. The device according to claim 1, wherein the second switch associated with each switching unit is arranged between the switching output of said switching unit and the modulated signal output.

6. The device according to claim 1, wherein the first, second and third switches comprise transistors.

7. The device according to claim 6, wherein the first, second and third switches comprise diodes connected in parallel with respectively each of the transistors of said switches and directed so as to be on when said transistor is reverse-biased.

8. The device according to the claim 7, wherein the transistors of the first, second and third switches are insulated gate bipolar transistors.

9. The device according to the claim 6, wherein the transistors of the first switches are silicon carbide field effect transistors, and the second and third switches comprise diodes connected in parallel with respectively each of the transistors of said switches and directed so as to be on when said transistor is reverse-biased.

10. The device according to the claim 7, wherein the transistor of the first switch of each switching unit s a MOS field effect transistor, the second switch associated with said switching unit comprising several series-connected diodes in parallel with the transistor of said second switch and directed so as to be on when said transistor is reverse-biased.

11. The device according to the claim 7, comprising a fifth switch connected between the reference voltage line and the modulated signal output.

12. The device according to the claim 11, wherein the fifth switch comprises two MOS field effect transistors connected in series and directed so as to conduct the current in opposite directions, said fifth switch comprising, for each of said two transistors, a diode (connected in parallel on said transistor and directed so as to be on when said transistor is reverse-biased.

13. The device according to claim 1, comprising for each switching unit:

first control means acting on the first switch of said switching unit to close or open said first switch to switch from the first switched state to the second switched state, in one direction or the other, while keeping the third switch open,

second control means acting on the third switch of said switching unit to close said third switch after switching from the second switched state to the first switched state.

14. An uninterruptible power supply comprising a power supply input on which an AC input voltage is applied, a rectifier connected to said input, two substantially DC voltage lines of opposite signs connected on output from said rectifier, an inverter connected to said substantially DC voltage lines and comprising an output designed to supply a secured voltage, wherein said inverter is a converter device according to claim 1 and supplies a AC secured voltage from substantially DC voltages.

3. The device according to the claim I, wherein each switching unit further comprises a fourth switch connected between the reference voltage line and the switching output of said switching unit to establish the second switched state when the first switch is open.

4. The device according to the claim 3, wherein the fourth switch of each switching unit is provided with a transistor and a diode connected in parallel on said transistor and directed so as to be on when said transistor is reverse-biased.