Switching converter control

Abstract

Switching converter control The present description relates to a method for controlling a converter comprising two H-bridges (110, 120) connected by a transformer (130), in which: repetitions of two switching sequences between several states are applied respectively to the two bridges; and the two sequences are generated from the same value representative of a difference between switching times of the two sequences: for a value of a ratio between voltages (V1, V2) at the terminals of the two bridges greater than a transformation ratio (n) of the transformer (130); and for a value of the ratio between the voltages less than the transformation ratio. Figure for the abstract: Fig. 1

Claims

Claims

1. A method of controlling a converter comprising two H-bridges (110, 120) connected by a transformer (130), the transformer having a winding (131) connecting together two nodes (141, 142) of one (110) of the H-bridges and another winding (132) connecting together two nodes (151, 152) of the other (120) of the H-bridges, the nodes (141, 142, 151, 152) being series connection nodes of the bidirectional voltage switches (T11H, T11L; T12H, T12L; T21H, T21L; T22H, T22L) of the respective branches (111, 112, 121, 122) of the H-bridges, wherein: - repetitions of two sequences (SA, SB) switching between several states (P, O, N) are applied respectively to the two bridges;and - the two sequences are generated from the same value (x, x') representative of a difference between switching times of the two sequences, said same value being chosen according to whether a ratio between the respective voltages (VI, V2) at the terminals of the H-bridges is greater or less than the transformation ratio (n) of the transformer.;

2. Method according to claim 1, in which switching times of the sequences (tAl, tA2, tBl, tB2, tB3, tB4) are calculated from a setpoint (P*) representative of a power to be transferred between the bridges, and the two sequences (SA, SB) are generated from said same representative value (x, x') for the same values ​​of a ratio between said setpoint (P*) and a product of said voltages (VI, V2).

3. Method according to claim 2, in which: - the setpoint (P*) is calculated as a function of a value (Vvi) of a voltage (VI) received by one of the bridges; and - preferably, the received voltage (VI) is alternating and the setpoint is calculated so that the converter has a PFC type operation.

4. Method according to claim 2 or 3, in which said switching instants result from calculations based on an equality between: - the power represented by the setpoint (P*); and - a power calculated from a model of the converter and from the voltage values ​​(VI, V2) at the terminals of the bridges.

5. Method according to claim 4, wherein said calculations are further based on a desired equality between values ​​(iO) of a current (1135) in the transformer (130) at a switching instant of one of the two sequences and at a switching instant of the other of the two sequences.

6. Method according to claim 4 or 5, in which, for each of said calculations, a frequency (f) common to said repetitions is chosen prior to the calculation.

7. Method according to any one of claims 1 to 6, in which, in each of the sequences (SA, SB), input and output switches of a given state (P, N) are located symmetrically with respect to a reference instant (tAS, tBS), the reference instants of the two sequences having between them a phase difference (d0).

8. Method according to claim 7, wherein the sequences (SA, SB) are generated on the basis of opposite desired values ​​of said phase difference (d0) for inverse values ​​of a ratio between the voltage ratio (VI, V2) and the transformation ratio (n).

9. A method according to claim 7 or 8, wherein said phase difference (d0) has opposite signs for two opposite directions of energy flow between the bridges (110, 120).

10. Method according to any one of claims 1 to 9, in which: - the two sequences (SA, SB) each comprise two respective switching cycles (SA1, SA2, SB1, SB2) of two branches (111, 112, 121, 122) of the bridge to which the sequence is applied; - the cycles of a first (SB) of the two sequences are out of phase with each other; and - the cycles of a second (SA) of the two sequences are inverse to each other.

11. Method according to claim 10, in which the cycles of the first (SB) and / or second of the two sequences have a duty cycle substantially equal to 0.

5.

12. A method according to claim 10 or 11, wherein the voltages (VI, V2) of said ratio between voltages are respectively those of a first of the bridges and of a second of the bridges, and the first and second of the bridges are switched respectively: - according to the first (SB) and second (SA) of the two sequences when the value of the ratio between voltages is greater than the transformation ratio (n); and - according to the second (SA) and first (SB) of the two sequences when the value of the ratio between voltages is lower than the transformation ratio (n).

13. A method according to any one of claims 10 to 12, wherein: - one of the states (P) of the first (SB) of the two sequences corresponds to a given direction of application of a voltage (VI, V2) to the transformer (130) by the bridge (110, 120) to which the first of the two sequences is applied; and - the first (SB) of the two sequences evolves during the same half-wave of an AC voltage (VI) at the terminals of one of the bridges, so that: • during at least a first period of time (810, 812), input and output switching of said one of the states occurs at the same state (N, P) of the second of the two sequences (SA); and • during at least a second period of time (820, 854), input and output switching of said one of the states occurs at states different from the second of the two sequences.

14.

15. Device (180) configured to implement a method according to any one of claims 1 to 13. Converter (100) comprising a device according to claim 14.

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