Electronic device and method for controlling, with optimized regulation, an electrical energy converter comprising a resonator, associated electrical energy conversion system

Abstract

Electronic device and method for controlling, with optimized regulation, an electrical energy converter comprising a resonator, associated electrical energy conversion system This device (20) for controlling a converter including a resonator and several switches (14), comprises: - a chain (42) for measuring a regulation quantity; - a chain (44) for controlling a switching of the switches (14), to alternate phases at substantially constant voltage and at substantially constant load at the terminals of the resonator, the control chain (44) comprising a loop for regulating a switching instant of a switch;- a synchronization module (40) for simultaneously sending a measurement order to the measurement chain (42) and a control order to the control chain (44), the duration of implementation of the measurement order by the measurement chain (42) being less than that of implementation of the control order by the control chain (44), so that the regulation quantity is measured before switching the switch. Figure for the abstract: Figure 3;

Description

Title of the invention: Electronic device and method for controlling, with optimized regulation, an electrical energy converter comprising a resonator, associated electrical energy conversion system

[0001] The present invention relates to an electronic device for controlling an electrical energy converter capable of converting an input voltage into an output voltage, the converter comprising two input terminals for receiving the input voltage, two output terminals for delivering the output voltage, a resonator, and several switches connected to the resonator.

[0002] The invention also relates to an electrical energy conversion system comprising such a converter and such an electronic device for controlling the converter.

[0003] The invention also relates to a method for controlling such a converter.

[0004] An electronic control device is known comprising a measuring chain configured to measure a regulation quantity of the converter; a control chain configured to control a switching of each of the switches, to alternate phases at substantially constant voltage at the terminals of the resonator and phases at substantially constant load at the terminals of said resonator, the control chain comprising a regulation loop configured to regulate, from the measured regulation quantity, a switching instant of a respective switch.

[0005] Indeed, control strategies, that is to say piloting, of direct-direct or DC-DC converters (from the English Direct Current-Direct Current) with six-phase piezoelectric resonator during a resonance cycle, with alternation of phases with substantially constant voltage at the terminals of the resonator and phases with substantially constant charge at the terminals of said resonator. However, these strategies use digital control, for example based on a component, or circuit, programmable logic, such as an FPGA (from the English Field Programmable Gate Array), which has certain limitations.

[0006] The maximum operating frequency of the controlled converters is limited by the sampling frequency and accuracy of the controller, i.e. of the control device used or the comparison speed in the case of using a comparator to, for example, detect the zero crossing of a current or zero crossing of the voltage derivative and directly actuate switches, as described in the following articles:

[0007] - JJ Piel, JD Boles, JH Lang and DJ Perreault, "Feedback Control for a Pie- zoelectric-Resonator-Based DC-DC Power Concerter” 2021 IEEE 22nd Workshop on Control and Modeling of Power Electronics (COMPEL);

[0008] - B. Pollet, G. Despesse and F. Costa, "A New Non-isolated Low-Power Inductorless Piezoelectric DC-DC Converter" in IEEE Transactions on Power Electronics, vol. 34, no. 11; and

[0009] - M. Touhami, G. Despesse, F. Costa and B. Pollet, “Implementation of Control Strategy for Step-down DC-DC Converter Based on Piezoelectric Resonator" 2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe).

[0010] Direct control of the switches via the control chain from the output of a comparator works up to some 100 kHz, but is no longer possible at a frequency of 10 MHz due to internal delays in the control chain, the delay from sending a control command via the output of the comparator until the actual switching of the corresponding switch then often being longer than the typical duration of the phase concerned.

[0011] The article by EA Stolt, WD Braun and JM Rivas-Davila, "Forward-Zero Cycle Closed-Loop Control of Piezoelectric Resonator DC-DC Converters" 2022 IEEE 23rd Workshop on Control and Modeling for Power Electronics (COMPEL), describes a step-down regulation, maintaining fixed-frequency operation with substantially constant control angles, but short-circuiting the resonator periodically during a complete resonance cycle to adjust the converter output power (burst mode). For example, by removing one resonance cycle out of five, the output power no longer sees power for one resonance period out of five and the energy supplied to the resonator is also reduced, limiting the amplitude of the current in the resonator and therefore the power transmitted over the other four periods.Besides the stability of the regulation which is not obvious, this leads to a current in the piezoelectric resonator higher than the strictly necessary current when the requested power is low compared to the maximum power.

[0012] The aim of the invention is then to propose an electronic control device, and an associated control method, allowing improved control of the electrical energy converter, in particular for an operating frequency greater than 1 MHz, and typically of the order of 10 MHz.

[0013] For this purpose, the invention relates to an electronic device for controlling an electrical energy converter capable of converting an input voltage into an output voltage, the converter comprising two input terminals for receiving the input voltage, two output terminals for delivering the output voltage, a resonator, and several switches connected to the resonator,

[0014] the electronic control device comprising:

[0015] - a measuring chain configured to measure a regulation quantity of the converter;

[0016] - a control chain configured to control a switching of each switches, for alternating phases with substantially constant voltage at the terminals of the resonator and phases with substantially constant charge at the terminals of said resonator,

[0017] the control chain comprising a control loop configured to regulate, from the measured control quantity, a switching instant of a respective switch;

[0018] - a synchronization module configured to simultaneously send a synchronization order measurement of the control quantity to the measuring chain and a control command of the respective switch to the control chain, and

[0019] the duration of implementation of the measurement command by the measuring chain is less than the duration of implementation of the control command by the control chain, so that the control quantity is measured before the switching of the respective switch.

[0020] Measuring the control quantity immediately before, i.e. just before, the actual switching of the respective switch then makes it possible to minimize an error in the control loop. The control quantity is advantageously representative of the voltage across the resonator, and measuring the control quantity just before the switching of the respective switch then makes it possible to minimize the error between the measured voltage and the desired constant voltage of the following phase.

[0021] This then makes it possible to obtain a low-frequency representation of the high-frequency switching error, which facilitates regulation of the conversion system at a lower frequency, independently of the operating speed of the converter.

[0022] According to other advantageous aspects of the invention, the electronic control device comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

[0023] - the respective switch is chosen from the group comprising:

[0024] + one of the switches, called the first switch, connected between one of the terminals input and the resonator, the first switch being switchable between an open position and a closed position in which the input voltage is applied across the resonator;

[0025] + one of the switches, called the second switch, connected between one of the terminals input and the resonator, the second switch being switchable between a position open and a closed position in which the voltage is zero across the resonator;

[0026] + one of the switches, called the third switch, connected between one of the terminals of output and the resonator, the third switch being switchable between an open position and a closed position in which energy from the resonator is returned to the output voltage;

[0027] - the regulation quantity is chosen from the group consisting of: the voltage at terminals of the resonator; the voltage between one of the terminals of the resonator and a reference potential, such as an electrical ground; the voltage across said respective switch; and the voltage between one of the terminals of said respective switch and a reference potential, such as an electrical ground;

[0028] - the measuring chain comprises two measuring probes adapted to measure the two end potentials of the voltage forming the regulation quantity, each measuring probe being adapted to measure a respective potential at a respective end of said voltage;

[0029] the voltage forming the regulation quantity being preferably then obtained by difference between the two end potentials measured respectively by the two measuring probes;

[0030] - the measuring chain comprises a sampling module connected to the two measuring probes; the sampling module comprising a first stage connected to the two measuring probes, a second stage connected to the output of the first stage and a differential unit connected to the output of the second stage; the first stage being configured to generate a first sampling pulse, and the second stage being configured to generate a second sampling pulse after the first sampling pulse; the second sampling pulse having a longer duration than the first sampling pulse;

[0031] a ratio between the duration of the second sampling pulse and that of the first sampling pulse being preferably greater than 10, more preferably greater than 15, and more preferably still substantially equal to 20;

[0032] the first stage preferably further including a pair of first sampling capacitors and a pair of first switches, each first switch being connected between a respective measuring probe and first capacitor and configured, when switched to the closed position, to allow charging of the respective first capacitor;

[0033] the second stage preferably further including a pair of second sampling capacitors and a pair of second switches, each second switch being connected to a respective second capacitor and configured, when switched to the closed position, to allow charging of the second respective capacitor;

[0034] - when the converter operates at an operating frequency greater than 1 MHz, the control quantity is measured between 0.5 ns and 20 ns, advantageously approximately 1 ns, before switching the respective switch;

[0035] - the resonator is a piezoelectric resonator;

[0036] the piezoelectric resonator preferably being constituted according to one of the constitutions among the group consisting of: a single piezoelectric element; several piezoelectric elements connected in series; several piezoelectric elements connected in parallel; a piezoelectric element and an auxiliary capacitor connected in series; a piezoelectric element and an auxiliary capacitor connected in parallel; and an arrangement of several parallel branches, each branch comprising one or more piezoelectric elements connected in series or an auxiliary capacitor;

[0037] the auxiliary capacitor preferably being of a higher capacity, more preferably at least three times higher, than a reference capacity of the piezoelectric element(s), each piezoelectric element being modeled in the form of a capacitor and a resonant branch connected in parallel to the capacitor, the reference capacity being the capacity of said capacitor;

[0038] - the resonator is an LC resonator comprising an inductor and a capacitor connected in series of the inductance;

[0039] - the simultaneous sending of a measurement order of the regulation quantity to the chain of measurement and a control command of the respective switch to the control chain is carried out for several switch commands during the same resonator resonance cycle; the duration of implementation of the measurement command by the measuring chain being less than the duration of implementation of the control command by the control chain, so that the control quantity is measured before the switching of the respective switch, for these several switch commands during the same resonance cycle;

[0040] these several switch commands during the same resonance cycle preferably being switch closures forming phase starts at substantially constant voltage at the terminals of the resonator;

[0041] - the control device comprises several control assemblies, and the number of control assemblies is equal to the number of switches whose switching is controlled by the control device, each control assembly comprising a respective synchronization module, a measurement chain and a control chain.

[0042] The invention also relates to an electrical energy conversion system comprising:

[0043] - an electrical energy converter capable of converting an input voltage into a output voltage, the converter having two input terminals for receiving the input voltage, two output terminals for delivering the output voltage, a resonator, and several switches connected to the resonator; and

[0044] - an electronic device for controlling the electrical energy converter; the electronic control device being as defined above.

[0045] The invention also relates to a method for controlling an electrical energy converter capable of converting an input voltage into an output voltage, the converter comprising two input terminals for receiving the input voltage, two output terminals for delivering the output voltage, a resonator, and several switches connected to the resonator,

[0046] the method being implemented by an electronic control device and comprising the following steps:

[0047] - measurement, via a measuring chain, of a regulation quantity of the converter;

[0048] - control, via a command chain, of a switching of each of the inter breakers, for alternating phases with substantially constant voltage at the terminals of the resonator and phases with substantially constant charge at the terminals of said resonator,

[0049] the control chain comprising a control loop configured to regulate, from the measured control quantity, a switching instant of a respective switch;

[0050] the method comprising, before the measuring and control steps:

[0051] - synchronization involving the simultaneous sending of a measurement order of the magnitude regulation to the measuring chain and a control order of the respective switch to the control chain, and

[0052] the duration of implementation of the measurement command by the measuring chain is less than the duration of implementation of the control command by the control chain, so that the control quantity is measured before the switching of the respective switch.

[0053] These characteristics and advantages of the invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the appended drawings, in which:

[0054] [Fig-1] [Fig.l] is a schematic representation of an electronic system of electrical energy conversion according to the invention, comprising an electrical energy converter comprising a resonator and several switches connected to the resonator; and an electronic device for controlling the electrical energy converter, the resonator being a piezoelectric resonator;

[0055] [Fig.2] [Fig.2] is a schematic representation of the energy converter electric when the resonator is an LC resonator;

[0056] [Fig.3] [Fig.3] is a schematic representation of the control device of the [Fig.l], this comprising a measurement chain for a regulation quantity of the converter and a control chain for switching each of the switches;

[0057] [Fig.4] [Fig.4] is a detailed view of a sampling module included in the measuring chain of [Fig.3];

[0058] [Fig.5] [Fig.5] is a flowchart of a method, according to the invention, of piloting of an electrical energy converter, the method being implemented by the control device of [Fig.l];

[0059] [Fig.6] [Fig.6] represents curves of the voltage and the intensity at the terminals of the piezoelectric resonator of [Fig.l], in voltage-boosting mode, and respectively in voltage-down mode, of the electrical energy converter; and

[0060] [Fig.7] [Fig.7] represents a curve of the voltage across the terminals of the piezo resonator electrical, a curve of a closing order of one of the switches of the electrical energy converter, a curve of a sampling order of the voltage at the terminals of the resonator and a curve of the sampled voltage.

[0061] In [Fig.l], an electronic electrical energy conversion system 5 comprises an electrical energy converter 10 comprising a resonator 12 and several switches 14 connected to the resonator 12. In the example of [Fig.l], the resonator 12 is a piezoelectric resonator 15, the switches 14 are denoted Kl, K2, K3. In the example of [Fig.2], the resonator 12 is an LLC resonator 18, the switches 14 are denoted S1, S2, S3, S4. In a variant not shown, the resonator 12 is a VHF type LC resonator, and the converter 10 then forms a VHF type LC resonance converter, as for example described in the thesis by Vincent Massavie entitled “VHF converter integrating innovative passive components”, published in 2023 on the HAL platform.

[0062] The conversion system 5 also comprises an electronic device 20 for controlling the electrical energy converter 10.

[0063] The electronic electrical energy conversion system 5 is typically a system for converting into direct electrical energy, such as a direct-direct conversion system capable of converting a first direct electrical energy received at the input into a second direct electrical energy delivered at the output, or even an alternating-direct conversion system capable of converting alternating electrical energy received at the input into direct electrical energy delivered at the output of the conversion system 5. The electrical energy is typically a voltage, or alternatively a current or a power.

[0064] When the electrical energy conversion system 5 is an AC-DC conversion system, the electrical energy conversion system 5 preferably further comprises a voltage rectifier, not shown, connected to the input of the electrical energy converter 10 and capable of rectifying the alternating electrical voltage received at the input of the conversion system 5 to deliver a rectified electrical voltage at the input of the converter 10, the electrical energy converter 10 preferably being a DC-DC converter capable of converting DC electrical energy into another DC electrical energy. The voltage rectifier is for example a rectifier bridge, such as a diode bridge. Alternatively, the voltage rectifier is formed in whole or in part by switches of the converter 10, for example via bidirectional voltage switches.

[0065] Those skilled in the art will observe that these different examples for the conversion system 5, whether it is a DC-DC conversion system or an AC-DC conversion system, are also presented in the documents FR 3 086 471 A1 and FR 3 086 472 A1, in particular with regard to their figures 1 to 3, 10, 15, 17 and 19 to 20.

[0066] The electrical energy converter 10 is preferably a DC-DC converter, and is also called a DC-DC converter. The DC-DC converter generally has the role of regulating a supply voltage Vout of a load 22 to a stable value, by being powered by an energy source 24 providing a substantially DC voltage Vin. The energy source 24 is for example a battery or a solar panel.

[0067] The electrical energy converter 10 is then configured to raise the value of the DC voltage between its input and its output, and is then also called a step-up DC-DC converter, or a high-step-up DC-DC converter; or is configured to lower the value of the DC voltage between its input and its output, and is then called a step-down DC-DC converter, with also a variant of a high-step-down DC-DC converter.

[0068] When the electrical energy converter 10 is a step-down DC-DC converter, the value of the input voltage typically corresponds to the voltage Vin of the energy source 24, and the value of the output voltage corresponds to the voltage Vout across the terminals of the load 22, the voltage Vin then being greater than the voltage Vout.

[0069] When the electrical energy converter 10 is a step-up DC-DC converter, the value of the input voltage also typically corresponds to the voltage Vin of the energy source 24, and the value of the output voltage corresponds to the voltage Vout across the terminals of the load 22, the voltage Vin then being lower than the voltage Vout.

[0070] When the electrical energy converter 10 is a strongly step-down DC-DC converter, the value of the input voltage corresponds for example to the voltage difference (Vin-Vout), and the output voltage value corresponds for example to the voltage Vout, the voltage difference (Vin-Vout) being significantly greater than the voltage Vout.

[0071] When the electrical energy converter 10 is a step-down DC-DC converter, according to a step-down variant, the value of the input voltage corresponds for example to the voltage difference (Vin-Vout), and the value of the output voltage corresponds to the voltage Vout across the terminals of the load 22, the voltage difference (Vin-V out) being greater than the voltage Vout.

[0072] The converter 10 comprises several switches 14 capable of being controlled to alternate phases at substantially constant voltage and phases at substantially constant load at the terminals of the resonator 12. This alternation of phases at substantially constant voltage and phases at substantially constant load is typically carried out within periods of substantially constant duration corresponding to the operating frequency of the converter 10, depending on an oscillation frequency, also called natural frequency or vibration frequency, of the resonator 12. The phases at substantially constant load make it possible, in steady state or permanent operation, to pass from one constant voltage to another and to close the switches which must be closed when the voltage at their terminals is preferably zero in order to have a so-called zero voltage switching, also called ZVS switching (from the English Zero Voltage Switching).

[0073] Each switch 14 comprises for example a transistor and an antiparallel diode (not shown) intrinsic to the transistor.

[0074] The transistor is, for example, an insulated gate field effect transistor, also called MOSFET (from the English Metal Oxide Semiconductor Field Effect Transistor). Alternatively, the transistor is a bipolar transistor; an insulated gate bipolar transistor, also called IGBT (from the English Insulated Gate Bipolar Transistor); a silicon (Si) based transistor, a GaN (from the English Gallium Nitride) based transistor; a silicon carbide (SiC) based transistor, or a diamond based transistor, or a thyristor, or a mechanical switch, such as a MEMS (from the English MicroElectroMechanical System) micro-switch.

[0075] By substantially constant charge, we mean an exchange of a charge with the outside which is less than 30% of the charge which would have been exchanged with the outside if the voltage had been kept constant. In other words, by substantially constant charge, we mean a variation in charge less than 30% of the charge which would have been exchanged with the outside of the resonator 12 if the voltage across the terminals of the resonator 12 had been kept constant over the time period considered.

[0076] By substantially open electrical circuit, we mean a circuit in which a possible leakage current leads to a variation in charge of the resonator 12 of less than 30% of the charge which would have been exchanged with the exterior of the resonator 12 if the voltage across the terminals of the resonator 12 had been kept constant over the time period considered.

[0077] By substantially constant voltage, we mean a voltage variation of less than 20%, preferably less than 10%, of the input or output voltage of the converter 10. For example, if the input voltage of the converter 10 is equal to 100V, then the voltage variation during each phase at substantially constant voltage, i.e. on each step at substantially constant voltage, is less than 20% of this voltage, i.e. less than 20V; preferably less than 10% of this voltage, i.e. less than 10V.

[0078] In the example of [Fig. 1], the control device 20 is configured to operate the piezoelectric material of the piezoelectric resonator 15 at its resonance in order to exploit charge transfer phases making it possible to dispense with the use of an inductive element, while regulating the output voltage by maintaining the resonance of the piezoelectric material, i.e. with repeated switching cycles at an operating frequency dependent on the oscillation frequency of the piezoelectric resonator 15, and by adjusting the durations of the respective switching phases within the resonance cycle.

[0079] As known per se, the mechanical oscillation of the piezoelectric resonator 15 is approximately sinusoidal. An increase or decrease in the energy stored over a period leads respectively to an increase or decrease in the oscillation amplitude.Furthermore, during a phase with substantially constant charge at the terminals of the piezoelectric resonator 15, that is to say when the piezoelectric resonator 15 is placed in a substantially open electrical circuit, with a low exchange of electrical charges between the piezoelectric resonator 15 and the exterior, an increase in the amplitude of the oscillations causes an increase in the speed of variation of the voltage Vp at the terminals of the piezoelectric resonator 15, and during a phase with substantially constant voltage at the terminals of the piezoelectric resonator 15, this increase in oscillation amplitude leads to an increase in the current exchanged between the piezoelectric resonator 15 and the exterior.

[0080] In the example of [Fig. 1], a first switch Kl is connected between one of the input terminals and the piezoelectric resonator 15, the first switch Kl being switchable between an open position and a closed position in which the input voltage Vin is applied to the terminals of the piezoelectric resonator 15.

[0081] A second switch K2 is connected across the piezoelectric resonator 15, the second switch K2 being switchable between an open position and a closed position in which the voltage is zero across the piezoelectric resonator. electric 15.

[0082] A third switch K3 is connected between one of the output terminals and the piezoelectric resonator 15, the third switch K3 being switchable between an open position and a closed position in which energy from the piezoelectric resonator 15 is returned to the output voltage Vout.

[0083] The oscillation frequency is the frequency at which the resonator 12, such as the piezoelectric resonator 15, oscillates and consequently its current IL on its motional branch (RLC branch) of its equivalent model around the selected resonance mode. The current IL can be deduced either by observing the evolution of the voltage Vp when the resonator is isolated or by observing its output current Ip during the constant voltage phases. The conversion cycle is synchronized with a mechanical movement of the piezoelectric resonator 15, and the control frequency is then set to the mechanical oscillation frequency. In practice, this oscillation frequency depends on the operating point of the converter 10: values ​​of the three voltage steps and the output current.Depending on the operating point, this oscillation frequency typically varies between the so-called series resonance frequency of the piezoelectric (cos=l / 'V(LC) where L and C correspond to the inductance and capacitance of a resonant branch 25 described below) and the so-called parallel resonance frequency of the piezoelectric (cop=l / 'V(L*C*Cp / (C+Cp))), also respectively called the resonance frequency and antiresonance frequency of the piezoelectric resonator 15. The operating frequency of the converter 10 is then between these two resonance and antiresonance frequencies of the piezoelectric resonator 15. The operating point varies slowly with respect to the oscillation frequency of the piezoelectric resonator 15. The operating point typically varies at less than 10kHz, while the oscillation frequency of the piezoelectric resonator 15 is typically greater than or equal to 100kHz.As a result, the operating frequency of the converter 10 changes little from one period to the next.

[0084] Generally, the total number of phases at substantially constant voltage during a resonance cycle is greater than or equal to one in a nominal operating mode of the converter 10.

[0085] In the example of [Fig.l] where the resonator 12 is the piezoelectric resonator 15, this total number of phases at substantially constant voltage is equal to three in nominal operating mode of the converter 10. Generally speaking, when the resonator 12 is the piezoelectric resonator 15, the total number of phases at substantially constant voltage during a resonance cycle is typically greater than or equal to three.

[0086] In the example of [Fig.2] where the resonator 12 is the LLC resonator 18, the total number of phases at substantially constant voltage is equal to two in operating mode. nominal operation of the converter 10. Generally, when the resonator 12 is the LLC resonator 18, the total number of substantially constant voltage phases during a resonance cycle is typically greater than or equal to two. The two substantially constant voltage phases typically correspond to +Vin and -Vin; or +Vin / 2 and -Vin / 2, where Vin represents the input voltage of the converter 10.

[0087] When in a variant not shown, the resonator 12 is the VHF type LC resonator, there is typically a single phase at substantially constant voltage in the nominal operating mode of the converter 10, and the converter 10 then typically comprises a single switch 14.

[0088] The piezoelectric resonator 15 is known per se, and is typically modeled, close to the resonance mode used, in the form of a capacitor Cp and the resonant branch 25 connected in parallel with the capacitor Cp, the capacitor Cp and the resonant branch 25 being connected between first 26 and second 27 electrodes of the piezoelectric resonator 15. The first 26 and second 27 electrodes form the terminals of the piezoelectric resonator 15.

[0089] In the example of [Fig.l], the piezoelectric resonator 15 comprises a single piezoelectric element.

[0090] In a variant not shown, the piezoelectric resonator 15 comprises several piezoelectric elements connected in series. Alternatively, the piezoelectric resonator 15 comprises several piezoelectric elements connected in parallel. Alternatively, the piezoelectric resonator 15 comprises a piezoelectric element and an auxiliary capacitor connected in series. Alternatively, the piezoelectric resonator 15 comprises a piezoelectric element and an auxiliary capacitor connected in parallel. As a further variant, the piezoelectric resonator 15 comprises an arrangement of several parallel branches, each branch comprising one or more piezoelectric elements connected in series or an auxiliary capacitor.

[0091] According to the variants concerned, the auxiliary capacitor is advantageously of greater capacity, more preferably at least three times greater, than a reference capacity of the piezoelectric element(s), such as the capacity of the capacitor Cp in the example of [Fig.l], each piezoelectric element being modeled in the form of a capacitor and a resonant branch connected in parallel with the capacitor, the reference capacity being the capacity of said capacitor.

[0092] In the example of [Fig.l], the first switch K1 is connected between a positive input terminal and the first electrode 26 of the resonator 15, the second switch K2 is connected between the first 26 and second 27 electrodes of the piezoelectric resonator 15, and the third switch K3 is connected between the first electrode 26 of the resonator 15 and a positive output terminal and the resonator 15. By positive terminal, those skilled in the art will understand that this is the terminal of positive polarity, that is, which is at the highest potential of the input voltage Vin, respectively of the output voltage Vout. In the example of [Fig.l], the negative input and output terminals are connected to an electrical ground GND.

[0093] The resonant branch 25 is typically an RLC branch formed of an auxiliary capacitor, a resistor and an inductor connected in series (not shown). The voltage Vp across the terminals of the piezoelectric resonator 15 then typically corresponds to the voltage across the terminals of the capacitor Cp.

[0094] The capacity of the auxiliary capacitor is advantageously greater than the capacity of the capacitor Cp, in particular at least three times greater.

[0095] In the example of [Fig.2], the resonator 12 is the LLC resonator 18, and the converter 10 then forms an LLC resonant converter. The switches 14 are denoted S1, S2, S3, S4.

[0096] The LLC resonant converter comprises a switching circuit 30, an LLC resonator 18 and a rectifier 32.

[0097] The switching circuit 30 is, for example, in the form of a full bridge, also called an H-bridge, as seen in [Fig.2], or a half-bridge (not shown). The switching circuit 30 receives the voltage Vin as input.

[0098] The switching circuit 30, in its H-bridge form, comprises for example four transistors 34 forming the switches 14, also denoted S1, S2, S3, S4. The transistors 34 are for example MOSFET transistors, such as N-type MOSFET transistors.

[0099] The LLC resonator 18 is connected to the output of the switching circuit 30, and is capable of receiving a voltage signal Vcm as input. The LLC resonator 18 comprises two inductors L and a capacitor C connected according to a known arrangement to form the LLC resonator. Advantageously, the LLC resonator 18 further comprises a transformer 36, connected to the output of the LLC arrangement and capable of delivering a voltage Vu. Those skilled in the art will observe that the inductance L parallel to the input of the transformer is all or part formed by the magnetizing inductance of the transformer and the inductance L in series is formed by all or part of the leakage inductance of the transformer. Those skilled in the art will also observe that the two inductances L are not necessarily identical and of the same value.

[0100] The rectifier 32 is connected to the output of the LLC resonator 18, and then able to receive the voltage Vu as input. The rectifier 32 is configured to rectify an alternating voltage into the direct voltage Vout at the output. In the example of [Fig.2], the rectifier 32 is in the form of a diode bridge 38, such as a four-diode bridge 38.

[0101] The control device 20 is configured to control the electrical energy converter 10, and in particular the switching of the switches 14 of the energy converter.

[0102] In the example of [Fig.3], the control device 20 comprises a synchronization module 40, a measuring chain 42 and a control chain 44 for a respective switch 14.

[0103] Advantageously, the control device 20 comprises a synchronization module 40, a measurement chain 42 and a control chain 44 for each of the respective switches 14. In other words, in the example of [Fig.l] where the energy converter 10 comprises three switches 14, the control device 20 then advantageously comprises three control assemblies, namely a control assembly for each respective switch 14, each control assembly comprising a respective synchronization module 40, a measurement chain 42 and a control chain 44.

[0104] More generally, the control device 20 comprises several control assemblies, and the number of control assemblies is equal to the number of switches 14 whose switching is controlled by the control device 20. The number of synchronization modules 40, the number of measurement chains 42 and the number of control chains 44 are then each equal to the number of switches 14 controlled by the control device 20.

[0105] The synchronization module 40, the measurement chain 42 and the control chain 44 are for example each produced in the form of an electronic circuit comprising one or more electronic components, and in particular comparators when comparisons are carried out.

[0106] Alternatively, the synchronization module 40, the measurement chain 42, and the control chain 44 are each produced in the form of a programmable logic component, such as an FPGA (Field Programmable Gate Array) or in the form of an integrated circuit, such as an ASIC (Application Specific Integrated Circuit) or in the form of a computer, such as a microcontroller, a processor. As a further alternative, the synchronization module 40, the measurement chain 42 and the control chain 44 are implemented together within a single hardware component, such as a single programmable logic component, a single integrated circuit, or a single computer.

[0107] Advantageously, the synchronization module 40, the measurement chain 42, and the control chain 44 are each produced using the same technology.

[0108] Advantageously, the synchronization module 40, the measurement chain 42, and the control chain 44 are each produced on the same substrate, for example on the same silicon substrate.

[0109] The synchronization module 40 is configured to simultaneously send a measurement order for a regulation quantity to the measurement chain 42 and a control order for a switch 14 to the control chain 44, the control order being more precisely sent to a unit 54 for controlling a respective switch 14, the control unit 54 being included in the control chain 44.

[0110] The measuring chain 42 is configured to, in the event of receipt of a measurement order from the synchronization module 40, carry out the measurement of a regulation quantity of the converter 10.

[0111] The regulation quantity is for example chosen from the group consisting of: the voltage Vp, Vcm at the terminals of the resonator 12; the voltage between one of the terminals of the resonator 12 and a reference potential, such as an electrical ground GND; the voltage at the terminals of said respective switch 14; and the voltage between one of the terminals of said respective switch 14 and a reference potential, such as the electrical ground GND.

[0112] The control chain 44 is configured to, in the event of receipt of a control order from the synchronization module 40, control a switching of each of the switches 14 in order to alternate phases at substantially constant voltage and phases at substantially constant charge at the terminals of said resonator 12.

[0113] A first duration Di of implementation of the measurement order by the measurement chain 42 is less than a second duration D2 of implementation of the control order by the control chain 44.

[0114] The difference between the first duration Di and the second duration D2 is characterized by the difference between the propagation times within the electrical or electronic elements of the measurement chain 42 and the control chain 44.

[0115] For example, the first duration Di is between 2 and 100 ns; and the second duration D2 is between 1 and 99 ns. The difference (Di - D2) between the first duration Di and the second duration D2 is typically less than 20 ns, and advantageously less than 5 ns.

[0116] The control variable is preferably measured just before switching the respective switch 14. For example, the control variable is measured substantially 1 ns before switching the respective switch 14.

[0117] The measuring chain 42 comprises two measuring probes 46, such as Kelvin probes, each being present at a respective terminal of the resonator 12 and a sampling module 48 and a unit 49 for controlling the sampling module 48, visible in [Fig.3].

[0118] The measurement probes 46 are configured to measure a potential Vp+ at a first terminal of the resonator 12, such as the first electrode 26, and a potential Vp at a second terminal of the resonator 12, such as the second electrode 27, as shown in [Fig.4]. Alternatively, the measurement probes 46 are configured to measure the potential difference at the terminals of one of the switches.

[0119] The sampling module 48 is connected to the output of the two measuring probes 46, and is then able to receive the potentials Vp+ and Vp as input.

[0120] The sampling module 48 is capable of delivering a voltage Vsamp, Vsamp corresponding to the voltage between the potentials Vp+ and Vp, i.e. to a subtraction between the sampled values ​​of the potentials Vp+ and Vp.

[0121] In the example of [Fig.3], the control chain 44 comprises a corrector 50, a generator 52 of a control signal and a unit 54 for controlling a respective switch 14.

[0122] The control device 20 advantageously comprises a control chain 44 as visible in [Fig.3] for each switch 14 of the converter 10.

[0123] The corrector 50 is typically configured to perform a regulation of the switching control of a respective switch 14, by receiving as input the voltage Vsamp from the sampling module 48, by calculating an error e between this voltage Vsamp and a target voltage, and then by performing an integration of this error e.

[0124] The corrector 50 comprises for example an operational amplifier 50A, a resistor 50B and a feedback loop with a capacitor 50C. The feedback loop connects the output of the operational amplifier 50A to its negative input. The electrical resistor 40B is connected between the input of the corrector 50 receiving the voltage Vsamp and the negative input of the operational amplifier 50A. This is an integrator type corrector, but of course other types of correctors can be used, for example proportional-integral, proportional-integral-derivative.

[0125] The control signal generator 52 is connected to the output of the corrector 50, and is configured to generate control signals for the switch 14, namely a periodic control signal for opening the switch 14, and respectively a periodic control signal for closing the switch 14, this as a function of the signal at the output of the corrector 50.

[0126] The control unit 54 is connected to the output of the generator 52 via the synchronization module 40, and is then able to receive as input the opening or closing control signal, respectively, from the generator 52.

[0127] The control unit 54 is connected to the input of the switch 14, the control device 20 of which is described here, and is configured to apply the opening control signal, or respectively the closing control signal, to a control electrode of the switch 14, such as a gate electrode when the switch 14 comprises a transistor such as a MOSFET or an IGBT.

[0128] Advantageously, the control unit 49 is configured to adjust more finely the time difference between a sampling instant tsa and a switching instant tcom which is later than the sampling instant tsa, by adding a time delay duration Dtemp to the first duration Di of implementation of the measurement order by the measuring chain 42.

[0129] According to this complement, the sampling instant tsa then verifies the following equation:

[0130] [Math.l] tsa ~ 6) D\ Dtemp

[0131] where tsa represents the sampling time,

[0132] to represents a synchronization instant between the measurement order and the control order, i.e. the instant at which the synchronization module 40 is configured to simultaneously send the measurement order and the control order,

[0133] Di represents the first duration of implementation of the measurement order by the measurement chain 42, and

[0134] Dtemp represents the time delay duration.

[0135] The switching instant tcom typically verifies the following equation:

[0136] [Math.2] tcom — h) + ^2

[0137] where tcom represents the switching time,

[0138] t0 represents the synchronization instant, and

[0139] D2 represents the second duration of implementation of the control order by the control chain 44.

[0140] The time delay duration Dtemp is preferably predefined, for example by means of a prior simulation of the measurement chain 42 on the one hand, and of the control unit 54 and the switch 14 on the other hand; and in particular by means of a prior simulation of the first duration Di of implementation of the measurement order by the measurement chain 42 on the one hand, and of the second duration D2 of implementation of the control order by the control chain 44 on the other hand. Those skilled in the art will observe that the corrector 50 and the control signal generator 52 have no impact on the second duration D2.

[0141] The time delay Dtemp then typically verifies the following equation:

[0142] [Math.3] Dtemp ~ D^ - D j - A

[0143] where Dtemp represents the time delay duration,

[0144] Di represents the first duration,

[0145] D2 represents the second duration, and

[0146] A represents a target time difference, i.e. a desired time difference, between the sampling instant U and the switching instant tcOm.

[0147] The target time difference A is for example between 1 and 20 ns, for example substantially equal to 2 ns.

[0148] The control unit 49 is connected to the output of the synchronization module 40, and is capable of delivering two sampling signals 0i and 02, namely a first signal sampling signal c^and a second sampling signal 02, to the sampling module 48, these first and second sampling signals ¢1, 02, being control signals of sampling stages 62, 64, as described hereinafter in more detail.

[0149] As seen in [Fig.4], the sampling module 48 comprises a sampling unit 58 and a differential unit 60.

[0150] The sampling unit 58 is connected to the two measuring probes 46 and to the control unit 49, and then capable of receiving as input the voltages Vp+ and Vp, as well as the sampling signals 0i and 02.

[0151] The sampling unit 58 comprises a first sampling stage 62 and a second sampling stage 64.

[0152] The first sampling stage 62 is connected to the two measurement probes 46 to receive the voltages Vp+ and Vp as input, and to the control unit 49 to receive the first sampling signal "^forming a control signal for the first sampling stage 62.

[0153] The first sampling stage 62 is configured to sample the voltages Vp+ and Vp over a very short duration, for example over a duration of one nanosecond.

[0154] The first sampling stage 62 comprises for example four transistors M1, M2, M3 and M4, two inversion logic gates 66 and two capacitors C1 and C2.

[0155] The transistors M1 and M2 are connected at the input to a first measuring probe 46, and capable of receiving the voltage Vp+ at the input.

[0156] The first sampling signal ¢1 is applied directly to the control electrode of the transistor M1, and is applied to the control electrode of the transistor M2 via the inversion logic gate 66.

[0157] Transistors Ml and M2 are connected to capacitor Cl by their first conduction electrodes. Transistors Ml and M2 are configured to, when in the closed position, allow the capacitor CL to charge.

[0158] The transistors M3 and M4 are connected at the input to a second measuring probe 46, and capable of receiving the voltage Vp at the input.

[0159] The first sampling signal ¢1 is applied directly to the control electrode of transistor M3, and is applied to the control electrode of transistor M4 via the inversion logic gate 66.

[0160] Transistors M3 and M4 are connected to capacitor C2 by their first conduction electrodes. Transistors M3 and M4 are configured to, when in the closed position, allow charging of capacitor C2.

[0161] In the example of [Fig.4], transistors M1 and M3 are N-type insulated gate field effect transistors (more commonly called MOSFETs); transistors M2 and M4 are insulated gate field effect transistors (more commonly called MOSFETs) named MOSFET) of type P, which explains the use of the inversion logic gates 66 for the control of the transistors M2 and M4.

[0162] The first sampling stage 58 is capable of delivering a voltage VC1 across the terminals of the capacitor C1 and a voltage VC2 across the terminals of the capacitor C2.

[0163] The second sampling stage 64 is connected to the output of the first sampling stage 62, and then able to receive the voltages Vci and Vc2.

[0164] The second sampling stage 64 is configured to sample the output voltages of the first sampling stage 62 over a longer duration, for example over a duration of ten nanoseconds.

[0165] The second sampling stage 64 comprises for example four transistors M5, M6, M7 and M8, two inversion logic gates 66 and two capacitors C3 and C4.

[0166] Transistors M5 and M6 are connected at the input to capacitor Cl, and are then able to receive voltage Vci at the input.

[0167] The second sampling signal 4>2 is applied directly to the control electrode of M5, and is applied to the control electrode of M6 via the inversion logic gate 66.

[0168] Transistors M5 and M6 are connected to capacitor C3 by their first conduction electrodes. Transistors M5 and M6 are configured to, when in the closed position, allow charging of capacitor C3.

[0169] Transistors M7 and M8 are connected at the input to capacitor C2, and then able to receive at the input the voltage VC2-

[0170] The second sampling signal ¢2 is applied directly to the control electrode of M7, and is applied to the control electrode of M8 via the inversion logic gate 66.

[0171] Transistors M7 and M8 are connected to capacitor C4 by their first conduction electrodes. Transistors M7 and M8 are configured to, when in the closed position, allow charging of capacitor C4.

[0172] The second sampling stage 64 is capable of delivering a voltage Vsampi across the terminals of the capacitor C3 and a voltage Vsamp2 across the terminals of the capacitor C4.

[0173] In the example [Fig.4], transistors M5 and M7 are N-type insulated gate field effect transistors (more commonly called MOSFETs); transistors M6 and M8 are P-type insulated gate field effect transistors (more commonly called MOSFETs), which explains the use of inversion logic gates 66 for controlling transistors M6 and M8.

[0174] The ratio between the sampling signal 0i and the sampling signal 02 is preferably greater than 10, more preferably greater than 15, and more preferably still substantially equal to 20.

[0175] The differential unit 60 is connected to the output of the second sampling stage 64 and then able to receive as input the voltages Vsampi and

[0176] The differential unit 60 is intended to deliver a voltage Vsamp resulting from the difference between the voltages Vsampi and Vsamp2.

[0177] The differential unit 60 comprises for example an operational amplifier 68, three electrical resistors 70 and a feedback loop with another electrical resistor 70. The feedback loop connects the output of the operational amplifier 68 to its negative input. A first of the three resistors 70 is connected between the voltage Vsampi and the negative input of the operational amplifier. A second of the three resistors 70 is connected between the voltage Vsamp2 and the positive input of the operational amplifier 68. A third of the three resistors 70 is connected between the potential Vmc of the circuit and the positive input of the operational amplifier 68.

[0178] Advantageously, the values ​​of the resistors 70 are all substantially equal so that Vsamp is equal to Vsampi - Vsamp2.

[0179] The first sampling signal 0b, for example, of a duration substantially equal to 1 ns, then activates four transistors M1, M2, M3 and M4, charging the two sampling capacitors C1 and C2 with the values ​​of the voltages Vp+ and Vp. Independently of the measured error, the sampling is always carried out before the switching of the corresponding switch 14. For example, the first sampling signal ¢1 is generated by the control unit 49 a few nanoseconds (> 2 ns) before the switching of the corresponding switch 14, that is to say a few nanoseconds, for example substantially 2 ns, before the switching instant tcom.

[0180] The second sampling signal 02 is delayed relative to the first sampling signal 0b for example by approximately 20 ns, and has a longer active duration than the first sampling signal 0b for example by a duration substantially equal to 10 ns, with a rise / fall time higher than that of the first sampling signal 0b in order to reduce the variations due to the charge injected on the sampled voltages Vsampi and Vsamp2. The sampled signals are then subtracted using the differential unit 60, for example the operational amplifier 68 in subtractor configuration, with a gain of 1. This assembly also adds a common mode Vmc to the voltage Vsamp.

[0181] The first sampling stage 62 must sample over a very short duration (1 ns for example), which implies transistors Ml to M4 large enough to be able to charge the capacitors Cl, C2 over such a short time. The control of these transistors Ml to M4 requires bringing / removing a large quantity of charge on their control electrode. The injection / removal of this large charge disturbs the source potential of these transistors and therefore the voltage across the capacitors Cl, C2, namely a first disturbance in one direction on closing, then a second disturbance in the other direction on closing. disturbance in the other direction at opening. This would be harmful for the second sampling stage 64 and the differential unit 60 which would be noisy; however, the first and second disturbances compensate for each other (disturbance in one direction, then in the other) and the voltage across the capacitors C1, C2 is stable over the rest of the period.

[0182] The second sampling stage 64 then samples the voltage across the capacitors C1, C2 over a stable voltage time zone. This second sampling is much less constrained and can be done over a much longer duration, such as 10ns, which makes it possible to use much smaller transistors M5 to M8 which require much fewer charges to be controlled, charges which do not or only slightly disturb the voltage across the capacitors C3 and C4. The differential unit 60 at the output of the capacitors C3 and C4 is then not or only slightly disturbed.

[0183] The nominal operation of a cycle of the converter 10 comprising a piezoelectric resonator 15 will now be described with regard to [Fig.6] showing the successive phases of a resonance cycle of the piezoelectric resonator, according to a generic format corresponding to different operating modes of the converter 10, namely a first operating mode F1, also called voltage-boosting mode; and a second operating mode F2, also called voltage-stepping mode.

[0184] [Fig.6] then represents the evolution of the current [3*IL of the normalized current IL in amplitude circulating in the piezoelectric resonator 15 visible in [Fig.l]; of the voltage Vp at the terminals of the piezoelectric resonator 15; and of the mechanical deformation of the piezoelectric resonator 15, represented by the curve DM; this during a resonance cycle and for two operating modes of the converter 10, namely the first operating mode Fl in voltage booster, and the second operating mode F2 in voltage step-down. With [3=-1 in voltage booster operating mode Fl; and [3=+l in voltage step-down operating mode F2.

[0185] By convention, a first switching time instant, denoted tb, corresponds to the closing of the first switch Ki for the first mode F1, respectively of the third switch K3 for the second mode F2, and the voltage Vp across the terminals of the piezoelectric resonator 15 is then substantially constant and equal to the input voltage Vin according to the first mode F1, or to the output voltage Vout according to the second mode F2. At this first switching time instant ti then begins a first phase I lasting until the opening of the switch which was closed at the first switching time instant tb.

[0186] A second switching time instant, noted t2, corresponds to the opening of the first switch Ki for the first mode Fl, respectively of the third in switch K3 for the second mode F2, and the voltage Vp across the terminals of the piezoelectric resonator 15 then changes from a previous voltage Vin according to the first mode Fl, or Vout according to the second mode F2, to an open circuit position. At this second switching time instant t2 then begins a second phase II lasting until a time instant t3 corresponding to a zero crossing of the current IL flowing in the piezoelectric resonator 15. Previously, the time instant t2 has been defined so that at the time instant t3, the voltage Vp across the terminals of the piezoelectric resonator 15 reaches a value corresponding to the value allowing zero voltage switching of the corresponding switch.

[0187] At time instant t3, a third phase III begins, at substantially constant voltage at zero value according to the first mode Fl via the closing of the second switch K2, or the input voltage Vin according to the second mode F2 via the closing of the first switch Kb and lasts until a time instant t4 which forms an adjustment parameter of the converter 10, this time instant t4 making it possible to define the voltage, the current or even the desired power at the output of the converter 10.

[0188] The time instant t4 then corresponds to the end of the third phase III and to the instant at which the second switch K2 according to the first mode F1, or respectively the first switch Ki according to the second mode F2, must then be open, the time instant t4 forming a fourth switching time instant corresponding to the opening of the second switch K2 according to the first mode F1, or respectively of the first switch Ki according to the second mode F2.

[0189] At the fourth switching time instant, a fourth phase IV begins, corresponding to a phase with a substantially constant load, or else in a substantially open circuit, this fourth phase IV lasting until a time instant t5 defined by the transition to a new predefined value of the voltage Vp at the terminals of the piezoelectric resonator 15. When the converter 10 comprises three switches K i, K2, K3 capable of being controlled to alternate phases with a substantially constant voltage and phases with a substantially constant load at the terminals of the piezoelectric resonator 15, the time instant t5 forming the end of the fourth phase IV typically corresponds to the closing of the third switch K3 according to the first mode F1, or respectively of the second switch K2 according to the second mode F2, the time instant t5 then forming a fifth switching time instant.

[0190] At the time instant t5 then begins a fifth phase V corresponding to a phase at substantially constant voltage at the output voltage Vout according to the first mode Fl via the closing of the third switch K3, or at the zero value according to the second mode F2 via the closing of the second switch K2. This fifth phase V lasts until a time instant to, or again until a time instant t6 modulo the period T of the resonance cycle defined by the zero crossing of the current IL flowing in the piezoelectric resonator 15, and according to a monotony opposite to that of the zero crossing at the time instant t3. By convention, the time instant t6 is equal to the sum of the time instant t0 and the period T of the resonance cycle, and is also noted (t0+T).

[0191] In the example of [Fig.6], the time instant t6 corresponds to the end of a resonance cycle of the piezoelectric resonator 15, the cycle represented having been defined in relation to the time instants of zero crossing of the current IL flowing in the piezoelectric resonator 15, and not in relation to the first switching time instant tb

[0192] The time instant t0, or the time instant t6, is obtained via the opening of the third switch K3 according to the first mode F1, or respectively of the second switch K2 according to the second mode F2, and then forms a sixth switching time instant.

[0193] From the zero crossing of the current IL flowing in the piezoelectric resonator 15 then begins a sixth phase VI corresponding to a phase with substantially constant charge, this sixth phase VI phase flowing between the time instant t6 and the time instant t6+ti, or between the time instant t0 and the time instant ti in the example of [Fig.6], it being understood that the time instant t6 corresponds to the time instant t0 to within one resonance cycle. The end of this sixth phase VI corresponds to the moment when the voltage Vp at the terminals of the piezoelectric resonator 15 reaches the input voltage Vin according to the first mode Fl, or to the output voltage Vout according to the second mode F2.

[0194] The method for controlling an electrical energy converter 10 via the control device 20 will now be described with reference to the flowchart of [Fig.5], the method comprising three distinct steps.

[0195] The method which will follow is advantageously implemented before each substantially constant voltage level, that is to say before each substantially constant voltage phase, and for the respective switch 14 associated with this substantially constant voltage level, as explained previously.

[0196] During the first step 100, the synchronization module 40 simultaneously sends to the measuring chain 42 an order to measure the regulation quantity and to the control chain 44 an order to control the respective switch 14.

[0197] During the second step 110, after receiving the measurement order from the synchronization module 40, the measurement chain 42 measures the regulation quantity of the converter 10. The measurement of the regulation quantity is then carried out at the sampling instant tsa.

[0198] The regulation quantity of the converter 10 is typically chosen from the group consisting of: the voltage across the terminals of the resonator 12; the voltage between one terminals of the resonator 12 and a reference potential, such as an electrical ground; the voltage across said respective switch 14; the voltage between one of the terminals of said respective switch 14 and a reference potential, such as an electrical ground.

[0199] During the third step 120, after receiving the control order from the synchronization module 40, the control chain 44 controls the respective switch 14. The control of the switch 14 is then effective at the switching instant tcom

[0200] Advantageously, the control unit 49 adjusts more finely the time difference between the sampling instant tsa and the switching instant tcom subsequent to the sampling instant tsa, by adding the time delay duration Dtemp to the first duration Di of implementation of the measurement order by the measurement chain 42.

[0201] The switching instant tcom then occurs just after the sampling instant tsa, the target time difference A, i.e. the desired time difference, between the sampling instant tsa and the switching instant tcom being advantageously between 0.5 and 20 ns, for example substantially equal to 2 ns.

[0202] The regulation of the converter 10 is then more precise, this being carried out during the subsequent plateau at substantially constant voltage from the value of the regulation quantity measured just before the start of this plateau.

[0203] [Fig.7] represents a curve 200 of the control order received by the respective switch 14 (in the example 12V corresponds to an opening order and 5V to a closing order), a curve 210 of the sampling signal forming the measurement order of the regulation quantity, a curve 220 of the voltage Vp across the resonator 12, and a curve 230 of the measured value of the regulation quantity. In the example of [Fig.7], the regulation quantity is the voltage Vp across the resonator 12.

[0204] Those skilled in the art will then observe that the sampling order occurs immediately before the closing of the respective switch 14, the measured quantity visible on the curve 230 is then equal to the value of the voltage Vp across the terminals of the resonator 12 just before the closing of the respective switch 14.

[0205] It is thus understood that the electronic control device 20 and the control method according to the invention allow better regulation with a more precise measurement of the regulation quantity just before at least one instant of closure of a respective switch 14, and preferably before each instant of closure of switch 14. This better regulation then allows improved control of the electrical energy converter 10.

[0206] Advantageously, the values ​​of the regulation quantity are measured systematically and periodically before the successive closing times of the switches. 14, that is to say before each start of phase at substantially constant voltage.

Claims

Claims

1. Electronic device (20) for controlling an electrical energy converter (10) capable of converting an input voltage (Vin) into an output voltage (Vout), the converter (10) comprising two input terminals for receiving the input voltage (Vin), two output terminals for delivering the output voltage (Vout), a resonator (12), and several switches (14) connected to the resonator (12), the electronic control device (20) comprising: - a measuring chain (42) configured to measure a regulation quantity of the converter (10);- a control chain (44) configured to control a switching of each of the switches (14), to alternate phases at substantially constant voltage at the terminals of the resonator (12) and phases at substantially constant load at the terminals of said resonator (12), the control chain (44) comprising a regulation loop configured to regulate, from the measured regulation quantity, a switching instant of a respective switch (14);characterized in that it further comprises: - a synchronization module (40) configured to simultaneously send a measurement order of the regulation quantity to the measurement chain (42) and a control order of the respective switch (14) to the control chain (44), and in that the duration of implementation of the measurement order by the measurement chain (42) is less than the duration of implementation of the control order by the control chain (44), so that the regulation quantity is measured before the switching of the respective switch (14).;

2. Device (20) according to claim 1, wherein the respective switch (14) is selected from the group comprising: - one of the switches (14), called the first switch (K1), connected between one of the input terminals and the resonator (12), the first switch (K1) being switchable between an open position and a closed position in which the input voltage (Vin) is applied to the terminals of the resonator (12); - one of the switches (14), called the second switch (K2), connected between one of the input terminals and the resonator (12), the second in- switch (K2) being switchable between an open position and a closed position in which the voltage is zero across the terminals of the resonator (12); - one of the switches (14), called the third switch (K3), connected between one of the output terminals and the resonator (12), the third switch (K3) being switchable between an open position and a closed position in which energy from the resonator (12) is restored to the output voltage (Vout).

3. Device (20) according to claim 1 or 2, wherein the regulation quantity is selected from the group consisting of: the voltage (Vp) across the resonator (12); the voltage between one of the terminals of the resonator (12) and a reference potential, such as an electrical ground (GND); the voltage across said respective switch (14); and the voltage between one of the terminals of said respective switch (14) and a reference potential, such as an electrical ground (GND).

4. Device (20) according to claim 3, in which the measuring chain (42) comprises two measuring probes (46) adapted to measure the two end potentials of the voltage forming the regulation quantity, each measuring probe (46) being adapted to measure a respective potential at a respective end of said voltage; the voltage (Vsamp) forming the regulation quantity being preferably then obtained by the difference between the two end potentials measured respectively by the two measuring probes (46).

5. Device (20) according to claim 4, wherein the measurement chain (42) comprises a sampling module (48) connected to the two measurement probes (46); the sampling module (48) comprising a first stage (62) connected to the two measurement probes (46), a second stage (64) connected to the output of the first stage (62) and a differential unit (60) connected to the output of the second stage (64); the first stage (62) being configured to generate a first sampling pulse, and the second stage being configured to generate a second sampling pulse after the first sampling pulse; the second sampling pulse having a longer duration than the first sampling pulse;a ratio between the duration of the second sampling pulse and that of the first sampling pulse being preferably greater than 10, more preferably greater than 15, and more preferably still substantially equal to 20; the first stage (62) further preferably including a pair of first sampling capacitors (C1, C2) and a pair of first switches (M1-M2, M3-M4), each first switch (M1-M2, M3-M4) being connected between a measuring probe (46) and a respective first capacitor (C1, C2) and configured, when switched to the closed position, to allow the charging of the respective first capacitor (C1, C2); the second stage (64) further preferably including a pair of second sampling capacitors (C3, C4) and a pair of second switches (M5-M6, M7-M8), each second switch (M5-M6, M7-M8) being connected to a respective second capacitor (C3, C4) and configured, when switched to the closed position, to allow the charging of the respective second capacitor (C3, C4).

6. Device (20) according to any one of the preceding claims, wherein when the converter (10) operates at an operating frequency greater than 1 MHz, the regulation quantity is measured between 0.5 ns and 20 ns, advantageously substantially 1 ns, before switching of the respective switch (14).

7. A device (20) according to any one of claims 1 to 6, wherein the resonator (12) is a piezoelectric resonator (15); the piezoelectric resonator (15) preferably being constituted according to one of the constitutions from the group consisting of: a single piezoelectric element; a plurality of piezoelectric elements connected in series; a plurality of piezoelectric elements connected in parallel; a piezoelectric element and an auxiliary capacitor connected in series; a piezoelectric element and an auxiliary capacitor connected in parallel; and an arrangement of a plurality of parallel branches, each branch comprising one or more piezoelectric elements connected in series or an auxiliary capacitor;the auxiliary capacitor preferably being of a higher capacity, more preferably at least three times higher, than a reference capacity of the piezoelectric element(s), each piezoelectric element being modeled in the form of a capacitor and a resonant branch connected in parallel to the capacitor, the reference capacity being the capacity of said capacitor.;

8. Device (20) according to any one of claims 1 to 6, wherein the resonator (12) is an LC resonator (18) having an in- ductance (L) and a capacitor (C) connected in series with the inductance (L).

9. Device (20) according to any one of the preceding claims, wherein the simultaneous sending of a measurement order of the control quantity to the measuring chain (42) and of a control order of the respective switch (14) to the control chain (44) is carried out for several switch (14) commands during the same resonance cycle of the resonator (12); the duration of implementation of the measurement order by the measuring chain (42) being less than the duration of implementation of the control order by the control chain (44), so that the control quantity is measured before the switching of the respective switch (14), for these several switch (14) commands during the same resonance cycle; these several switch commands (14) during the same resonance cycle preferably being switch closures (14) forming phase starts at substantially constant voltage at the terminals of the resonator (12).

10. Device (20) according to claim 9, wherein the control device (20) comprises several control assemblies, and the number of control assemblies is equal to the number of switches (14) whose switching is controlled by the control device (20), each control assembly comprising a respective synchronization module (40), a measurement chain (42) and a control chain (44).

11. Electrical energy conversion system (5) comprising: - an electrical energy converter (10) capable of converting an input voltage (Vin) into an output voltage (Vout), the converter (10) comprising two input terminals for receiving the input voltage (Vin), two output terminals for delivering the output voltage (Vout), a resonator (12), and several switches (14) connected to the resonator (12); and - an electronic device (20) for controlling the electrical energy converter (10); characterized in that the control device (20) is according to any one of the preceding claims.

12. Method for controlling an electrical energy converter (10) capable of converting an input voltage (Vin) into an output voltage (Vout), the converter (10) comprising two input terminals for receiving the input voltage (Vin), two output terminals for delivering the input voltage (Vout), and two output terminals for delivering the output voltage (Vout). output (Vout), a resonator (12), and several switches (14) connected to the resonator (12), the method being implemented by an electronic control device (20) and comprising the following steps: - measurement (110), via a measuring chain (42), of a regulation quantity of the converter (10); - control (120), via a control chain (44), of a switching of each of the switches (14), to alternate phases at substantially constant voltage at the terminals of the resonator (12) and phases at substantially constant charge at the terminals of said resonator (12), the control chain (44) comprising a control loop configured to regulate, from the measured control quantity, a switching time of a respective switch (14); characterized in that it further comprises, before the measuring and control steps: - a synchronization step (100) comprising the simultaneous sending of a measurement order for the regulation quantity to the measurement chain (42) and a control order for the respective switch (14) to the control chain (44), and in that the duration of implementation of the measuring command by the measuring chain (42) is less than the duration of implementation of the control command by the control chain (44), so that the control variable is measured before the respective switch (14) is switched on.

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