Switch control

Patent metadata

Field	Value
Publication number	US-2021159780-A1
Application number	US-202016950707-A
Country	US
Kind code	A1
Filing date	Nov 17, 2020
Priority date	Nov 25, 2019
Publication date	May 27, 2021
Grant date	—

Abstract

A method of controlling first and second switches of a switching cell, including measuring a current flowing through the first switch when the first switch is controlled to the off state, and setting a switching dead time according to the measurement.

First claim

What is claimed is:

1 . A method of controlling first and second switches of a switching cell, wherein the first and second switches are series-coupled, and wherein the first switch comprises a diode, coupling terminals of the first switch and oriented to conduct a current supplied or received by the switching cell when the first and second switches are simultaneously in the off state, the method comprising measuring a current flowing through the first switch when the first switch is controlled to the off state, and setting a switching dead time according to the measurement,
wherein the setting comprises determining a value representative of an integral of a value resulting from the measurement during an integration period,
and wherein said setting comprises searching for a value of the switching dead time for which the value representative of the integral exhibits an extremum.

2 . The method according to claim 1 , wherein the measurement is performed when the second switch is controlled to the on state.

3 . The method according to claim 1 , wherein a duration of the integration period is predefined and/or in the range from 0.1% to 50% of a switching cycle time, and/or greater than or equal to a duration between two successive zero crossings of the current flowing through the first switch.

4 . The method according to claim 1 , wherein the integration period starts at a time when said value resulting from the measurement is representative of a zero value of the current flowing through the first switch.

5 . The method according to claim 1 , further comprising another measurement of another current flowing through the second switch when the second switch is controlled to the off state, wherein the setting of said switching dead time also takes into account said other measurement, and/or wherein the setting of another switching dead time is performed according to said measurement and/or to said other measurement.

6 . A device configured to implement the method according to claim 1 .

7 . A switching cell comprising the device according to claim 6 and the first and second switches.

8 . The cell according to claim 7 , comprising a sensor configured to measure the current flowing through the first switch.

9 . The cell according to claim 8 , wherein said sensor comprises a magnetic-type sensor, preferably a transformer.

10 . The cell according to claim 8 , comprising a third switch coupling output terminals of said sensor and, preferably, controlled by a same control signal as the first switch.

11 . The cell according to claim 8 , wherein said device comprises:
a comparator circuit and a link between an input of the comparator circuit and said sensor, another input of the comparator circuit being coupled to a first node of application of a fixed potential; a monostable circuit having a trigger input coupled to an output of the comparator circuit; a multiplexer controlled by the monostable circuit and having an input coupled to said sensor; and an integrator circuit having an input coupled to an output of the multiplexer, the integrator circuit preferably comprising a resistor and a capacitor in series between said input of the integrator circuit and the first node or another node of application of a fixed potential.

12 . The cell according to claim 11 , wherein:
said link comprises another multiplexer having an input coupled to said sensor and an output coupled to said input of the comparator circuit, said other multiplexer having another input coupled to the first node or to a second node of application of a fixed potential; and another monostable circuit has a trigger input coupled to the output of said monostable circuit and controls said other multiplexer.

13 . A switched-mode converter comprising at least one device according to claim 6 .

14 . A switched-mode converter comprising at least one cell according to claim 7 .

Assignees

• Commissariat A Ienergie Atomique Et Aux Energies Alternatives

Inventors

• Lefevre Guillaume
• Piquet-Boisson Guillaume

Classifications

• Y02B70/10

  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 title

• H02M1/38 Primary

  Means for preventing simultaneous conduction of switches · CPC title

• H02M1/083

  for the ignition at the zero crossing of the voltage or the current · CPC title

• H02M1/0009

  Devices or circuits for detecting current in a converter · CPC title

• H02M3/158

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