Power electronics converter with impedance measurement, energy transfer system and hybrid system comprising such a converter

Abstract

The invention relates to a power electronics converter suitable for transferring energy from an electrical energy source (S) such as an electrochemical electrical energy production source to an output device (DS) such as an electrochemical energy storage device. The converter is configured to receive input electrical quantities from the source and to supply appropriate electrical quantities to the output device. The converter according to the invention comprises n conversion arms (BC1,...BCx,... BCn) connected in parallel between its input IN and its output OUT and regulation means configured to control the operation of each conversion arm in real time. The converter according to the invention thus exhibits very good stability and is insensitive to interference. The converter also comprises means for determining an input and / or output impedance of the converter.

Description

[0001] DESCRIPTION

[0002] Title of the invention: Electronic power converter with impedance measurement, energy transfer system and hybrid system comprising such a converter

[0003] STATE OF THE ART

[0004] The invention relates to the transfer of energy from an electrical energy source to an output device. The source is for example an electrochemical source for producing electrical energy, for example a fuel cell, a supercapacitor, a battery, etc. The output device is for example a storage element such as an electrochemical device for storing electrical energy, commonly called a "storage battery" or even more simply a "battery". The output device can also be a distribution network, a motor, etc. The invention finds an application in particular for the production of SPAC (Fuel Cell Systems), comprising a fuel cell type source coupled to a DC / DC converter, an output device (battery, energy network, etc.) which can then be connected to the output of the SPAC.The invention also finds an application for the production of hybrid SPACs comprising, connected together, a fuel cell type source, a DC / DC converter and a storage element such as a battery, an output device (motor, etc.) which can then be connected to the output of the Hybrid SPAC.

[0005] The invention relates more particularly to optimizing the operation of the converter and monitoring the operation of the energy source and / or monitoring the operation of the output device.

[0006] An electrochemical source such as a fuel cell has a non-linear operation that evolves as energy is transferred. Similarly, an electrochemical storage device such as a storage battery has a non-linear charge or discharge cycle, the parameters of which evolve in particular according to the level of electrical charge or its duration of use. Thus, in order to optimize the transfer of electrical energy, it is necessary to adjust the operation of the converter in real time, especially when the source and / or the output device has / have a non-linear operation. Furthermore, monitoring of the input and / or output impedance of the converter is necessary in real time to ensure a correct and optimal transfer of energy through the source - converter - output device chain.

[0007] In a known manner, a converter is configured to receive on an input terminal I first and second electrical input quantities (lin, Vin) of current and / or voltage supplied by the source and is configured to supply on an output terminal OUT of the converter first and second electrical output quantities (lout, Vout) of current and / or voltage adapted to the output device.The converter conventionally comprises a conversion circuit and a regulation device; the conversion circuit is configured to provide the output device with the first output electrical quantity as a function of the first input electrical quantity that it receives from the source and as a function of regulation control signals; the regulation circuit produces the regulation control signals as a function of a measured value of the first input electrical quantity (lin) and as a function of an offset between an expected value (V*out) of the second output electrical quantity of the converter and a measured value of the second output electrical quantity (Vout), measured on the output terminal OUT.The first input electrical quantity, the current or the voltage, is thus regulated in real time according to the expected value of the second output electrical quantity, the voltage or the current, so that the first output quantity and the second output quantity are adapted to the output device. Depending on the input and / or output electrical quantities, the converter may be a step-up converter, a step-down converter or a buck-boost converter. It generally comprises a plurality of power switches connected in series or in parallel according to a conventional electronic scheme chosen according to the quantity to be converted and the desired conversion ratio.The signals applied to the switch controls are adjusted in real time according to the regulation control signals provided by the regulation circuit so as to adjust in real time the conversion ratio between the input IN and the output OUT of the converter. The regulation circuit typically comprises circuits for measuring the input and / or output quantities, analog or digital filters and analog or digital correction circuits.

[0008] In practice, it is found that, on such converters, the implementation of means for measuring impedance at the source terminals or at the output device terminals is difficult.

[0009] DESCRIPTION OF THE INVENTION

[0010] The present invention aims to overcome the drawbacks described above of known converters. To this end, the invention proposes a new electronic power converter suitable for transferring energy from a source (S) of electrical energy such as an electrochemical source for producing electrical energy to an output device (DS) such as an electrochemical energy storage device, converter configured to receive on an input terminal (IN) first and second electrical input quantities (lin, Vin, ) of current and voltage supplied by the source and configured to supply on an output terminal (OUT) of the converter first and second electrical output quantities (lout, Vout) of current and voltage adapted to the output device.

[0011] According to the invention, the converter comprises n regulated conversion arms connected in parallel between the input terminal IN and the output terminal OUT of the converter, n being an integer greater than or equal to two, each conversion arm (BCx) being configured to receive from the source a fraction (I in_x) of the first input electrical quantity, to control said fraction of the first input electrical quantity (lin_x) to the second output electrical quantity (Vout) and to supply the output device with a fraction (lout_x) of the first output electrical quantity (lout) adapted to the output device.

[0012] According to the invention, the converter also comprises means for determining an impedance, said impedance determining means comprising:

[0013] - a disturbance circuit arranged to produce and supply to an input of one of the conversion arms (BCx) a disturbance waveform (Px) comprising a harmonic component at at least one predefined frequency

[0014] - a processing means configured to measure the input electrical quantities (lin, Vin) of the converter and determine an input impedance of the converter at the predefined frequency as a function of the measured values ​​of the input electrical quantities and / or to measure output electrical quantities (lout, Vout) of the converter and determine an output impedance of the converter at the predefined frequency as a function of the measured values ​​of the output electrical quantities.

[0015] The invention thus proposes a converter comprising n regulated conversion arms connected in parallel and whose input is controlled by the voltage and current requirements of the output device, n being greater than or equal to two. If, during operation, one of the conversion arms experiences a disturbance affecting the energy transfer, the other conversion arm(s) are not disturbed and continue to operate optimally, ensuring the stability of the entire converter and guaranteeing optimal energy transfer to the output device.Furthermore, in the impedance determining means of the converter according to the invention, the disturbance waveform is applied to one conversion arm only, so that the other regulated conversion arms are not disturbed; the other regulated conversion arms continue to operate optimally, ensuring the overall stability of the converter and guaranteeing optimal energy transfer to the output device.

[0016] The disturbance waveform applied to the input of an arm of the converter results in a disturbance waveform at the input and output of the converter. The impedance values ​​determined for the predefined frequency(ies) at the input of the converter (therefore at the output of the source) and / or at the output of the converter (therefore at the input of the output device) provide information on the operation of the converter, but also on the operation of the source and on the operation of the output device. In particular, they make it possible to detect possible operating faults in the source-converter-output device transfer chain or in one of the components of said chain, to plan maintenance operations on one or other of the components of said chain, and even to modify the converter control means in real time.

[0017] According to one embodiment, to control the fraction of the first input electrical quantity (I in_x) to the second output electrical quantity (Vout) and to provide the output device with a fraction (lout_x) of the first output electrical quantity (lout) adapted to the output device, each conversion arm comprises control means (CCx, MRx) configured to measure a value (l°in_x) of said fraction of the first input electrical quantity (lin_x) and configured to control said fraction (lin_x) of the first input electrical quantity as a function of the measured value (l°in_x) of said fraction of the first input electrical quantity and of the second output electrical quantity (Vout).

[0018] The invention also relates to an energy transfer system comprising, connected together, an electrical energy source such as an electrochemical source for producing electrical energy and a converter as described above, an input terminal IN of the converter being connected to an output terminal of the source, and an output terminal of the converter being intended to be connected to an input terminal of an output device such as an electrochemical energy storage device. The invention finally relates to a hybrid system comprising an energy transfer system as described above, an output terminal of the converter being connected to an input terminal of an output device such as an electrochemical energy storage device.

[0019] BRIEF DESCRIPTION OF THE FIGURES

[0020] Other characteristics and advantages of the invention will appear on reading the detailed description below of embodiments of the invention, given by way of example only, and with reference to the appended drawings in which:

[0021] - Fig. 1 shows a schematic diagram of a converter according to the invention

[0022] - Fig. 2 shows an embodiment of an essential element of the invention

[0023] - Fig. 3 shows an embodiment of another essential element of the invention

[0024] - Fig. 4 shows signals present at the terminals of a converter according to the invention.

[0025] DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0026] As stated previously, the invention relates to a converter and an energy transfer system. The converter is a power electronic converter suitable for transferring energy from an electrical energy source such as an electrochemical source for producing electrical energy to an output device such as an electrochemical energy storage device. A block diagram of such a system is shown in Figure 1. The converter is configured to receive on an input terminal IN first and second input electrical quantities lin, Vin of current and / or voltage supplied by the source and is configured to supply on an output terminal OUT of the converter first and second output electrical quantities lout, Vout of current and / or voltage adapted to the output device.

[0027] According to the invention (figure 1), the converter comprises n regulated conversion arms BC1, ...BCx, ...BCn connected in parallel between the input terminal IN and the output terminal OUT of the converter. Each regulated conversion arm BCx of rank x is configured to receive from the source a fraction I in_x of the first input electrical quantity lin, to slave said fraction of the first input electrical quantity I in_x to the second output electrical quantity Vout and to supply to the output device a fraction lout_x of the first output electrical quantity lout adapted to the output device; n is an integer greater than or equal to two and x is an integer between 1 and n.

[0028] In the example shown, each regulated conversion arm comprises a conversion circuit CCI, ..., CCn, coupled to a regulation device MRI, ..., MRn together forming control means (CCx, MRx) configured to measure a value (l°in_x) of the fraction of the first input electrical quantity (I in_x) received from the source and configured to control said fraction (lin_x) of the first input electrical quantity as a function of the measured value (l°in_x) of said fraction of the first input electrical quantity and of the second output electrical quantity (Vout). For the sake of balance between the conversion arms of the electrical power to be transferred to the output device, all the conversion circuits CCI, ..., CCn are similar here, and all the regulation devices MRI, ..., MRn are also similar. The regulation devices MRI, ...MRn, each control the first electrical quantity at the input of the associated conversion circuit CCI, ..., CCn so that linl = ...lin_x = ... I_in_n = lin / n to guarantee a balanced power transfer between the n conversion arms.

[0029] Figure 2 details as an example a boost converter type CCx conversion circuit produced according to a conventional scheme based on two electronic switches controllable by an inductance. In one example, a controllable switch is produced in a conventional manner, by a diode and a transistor connected in parallel. Other electrical schemes for controllable switches are of course conceivable. Also conventionally, such a converter is controlled by a PWM (Pulse Width Modulation) type control, by rectangular, complementary, periodic digital signals RCx with a duty cycle Dx, each of the signals controlling the opening or closing of one of the switches of the CCx conversion circuit. In the example shown of a conversion circuit comprising two controlled switches, two signals RCxl, RCx2 are produced for each conversion circuit.The amplitude of the DC signal at the converter output is adjusted by adjusting the duty cycle of the control signals. Smoothing of the DC signal supplied at the output is obtained by adjusting the frequency of the control signals RCxl, RCx2 (switching frequency) and / or the duty cycle Dx. Other conversion circuits can of course be used, for example buck converter circuits, or a combination of a step-up circuit and a step-down circuit. The control of these conversion circuits is similar, although the number of control signals can vary depending on the type of conversion circuit chosen. The choice of conversion circuits is made in a conventional manner depending on the electrical quantities available at the source output and the electrical quantities expected by the output device.

[0030] In the example shown, the converter also comprises an MRO regulation control means. The MRO regulation control means is configured:

[0031] - to measure a value V°out of the second electrical output quantity Vout,

[0032] - to determine, for each conversion arm of rank x (BCx) an expected value I * in_x of a fraction of rank x I i n_x of the first input electrical quantity lin as a function of an offset V*out - V°out between an expected value V*out of the second output electrical quantity Vout and the measured value V°out of said second output electrical quantity Vout, and

[0033] - to provide the expected value of rank x I * in_x of the fraction of rank x I in_x of the first electrical input quantity lin to the conversion arm of rank x. In the concrete example of a battery-type output device that we are trying to charge, the expected value V*out is the nominal value at full load for the output device.

[0034] Figure 3 details an exemplary embodiment of the MRO regulation control means. MRO has an input connected to the output terminal S of the converter to receive the second electrical output quantity Vout. The MRO control means here comprises:

[0035] - a measuring device 11, for measuring the value V°out of the second electrical output quantity Vout;

[0036] - a subtractor 12, comprising a positive input to which the expected value V*out of the second electrical output quantity is applied and a negative input connected to the measuring device 11; the subtractor is here a digital subtractor;

[0037] - a correction device 13, to produce the expected value I *in of the first electrical input quantity;

[0038] - a distribution device 14 for producing the expected values ​​I *in_l, ..., I * in_n of the fractions l_in_l, ...,

[0039] I i n_n of the first electrical input quantity lin; in the example shown, to guarantee balanced power transfer, the expected values ​​are chosen to be equal to each other and equal to I *in_n: I *in_l = I *in_n = I *in / n.

[0040] The measuring device 11 of the MRO control means is produced in a manner known per se. It comprises, for example, associated in series between the input of the converter and the negative input of the subtractor 12, an analog voltmeter for measuring a voltage at the output of the converter, a voltage divider and an analog / digital converter, for adapting the measured analog signal to a digital value appropriate to the negative input of the subtractor 12. The correction device 13 comprises, for example, a calculation circuit configured to determine the expected value I *in (for example a Proportional Integral type circuit) and a limiting circuit configured to limit the amplitude of the determined expected value I *in to an amplitude acceptable for a regulation device MRx.In the concrete example of a non-linear output device such as a battery, the calculation circuit is configured to calculate l*in from a mathematical model of the battery behavior and the V*out - Vout offset. The distribution circuit 14 may be a divide-by-n circuit.

[0041] Figure 3 also details the regulation device MRx associated with the conversion circuit CCx. The regulation device MRx is configured to produce regulation control signals RCx (two signals RCxl, RCx2 here) as a function of an offset I * in_x - ln_x between the expected value I * in_x of the fraction of rank x of the first input electrical quantity lin and the value received from the source of the fraction I in_x of rank x of the first input electrical quantity (lin). The conversion circuit CCx described below is arranged to produce the fraction lout_x of rank x of the first output electrical quantity lout as a function of the regulation control signals. The conversion circuit CCx, coupled to the regulation device MRx, together form the servo-control means of a conversion arm.

[0042] The MRx regulation device has an input connected to an output terminal of the MRO regulation control means and it comprises here (fig. 3):

[0043] - a measuring device 21, for identifying on the input terminal of the conversion circuit CCx, the value of the fraction I in_x of the first electrical input quantity lin received from the source by said conversion circuit;

[0044] - a subtractor 22, comprising a positive input connected to the output of the regulation control means MRO to receive a fraction I *in_x of the expected value I *in of the first electrical input quantity determined by the regulation control means MRO, a negative input connected to an output of the second measuring device 21 and an output on which the offset I * in_x - ln_x between the expected value and the measured value is produced; the subtractor is here a digital subtractor;

[0045] - a correction device 23, for producing the regulation control signals RCxl, RCx2 associated with the conversion circuit CCx; in a concrete example, the correction device is of the Proportional Integral type (commonly called PI corrector).

[0046] The correction device 23 (not detailed in figure 3) may comprise, for example, associated in series:

[0047] - a calculation circuit configured to produce a value of the duty cycle Dx appropriate for correcting the offset determined by the subtractor, in a concrete example, the calculation circuit 23 is configured to calculate Dx from a mathematical model of the behavior of the converter and the offset I *in - I in, - a limiter circuit to limit the value of the duty cycle to a value acceptable by the conversion circuit CCx, and

[0048] - a circuit to translate the value of the duty cycle Dx into regulation control signals, RCxl and RCx2 here.

[0049] The measuring device 21 (not detailed in Figure 3) of the regulation device MRx is also produced in a conventional manner. In one example, it may comprise, associated in series between an input of the conversion circuit CCx and the negative input of the subtractor 22, an analog electronic circuit for measuring the value I in_x of the current at the input of the conversion circuit CCx, a voltage divider and an analog / digital converter, for adapting the measured analog signal to a value appropriate to the negative input of the digital subtractor 22.

[0050] According to another aspect of the invention, the converter also comprises means for determining an impedance, the impedance determining means comprising:

[0051] - a disturbance circuit CP arranged to produce and to supply to an input of a regulated conversion arm (BCx) of rank x a disturbance waveform (Px) comprising a harmonic component at at least one predefined frequency

[0052] - a processing means configured to measure the input electrical quantities (lin, Vin) of the converter and determine an input impedance of the converter at the predefined frequency as a function of the measured values ​​of the input electrical quantities and / or to measure output electrical quantities (lout, Vout) of the converter and determine an output impedance of the converter at the predefined frequency as a function of the measured values ​​of the output electrical quantities.

[0053] In the example shown in Figure 3, the disturbance circuit produces a disturbance waveform (or electrical signal) Px which is superimposed on the fraction I * in_x of the expected value of the input electrical quantity received by the regulation device MRx of the conversion arm BCx. And more precisely in this example, the disturbance circuit is a signal generator which produces a digital electrical signal which is applied to a second positive input of the subtractor 22. The disturbance waveform is thus taken into account in the calculation of the offset Px + I *in - lin.

[0054] The input impedance of the converter is equal to the output impedance of the source and the output impedance of the converter is equal to the input impedance of the output device. Since the output impedance of the source provides information about the operating state of the source, determining the input impedance of the converter in real time allows the operating state of the source to be monitored in real time and thus detect a possible fault or particular operating mode of the source. Similarly, since the input impedance of the output device provides information about the operating state of the output device, determining the output impedance of the converter in real time allows the operating state of the output device to be monitored in real time.

[0055] The processing means comprises a device for measuring the input electrical quantities lin, Vin of the converter and / or a device for measuring the output electrical quantities lout, Vout of the converter, and an impedance calculation device.

[0056] The measuring device (not detailed in the figures), at the input or output of the converter, may include for example:

[0057] - a measuring circuit configured to measure the first and second input electrical quantities (lin, Vin) of current and / or voltage, and / or to measure the first and second output electrical quantities (lout, Vout) of current and / or voltage,

[0058] - a device for filtering the measured signals configured to filter a continuous component of said measured signals.

[0059] The filtering device can also be configured to determine, for the predefined frequency or for each predefined frequency, the amplitude of the harmonic component of the first electrical quantity (the current in the example) and the amplitude of the harmonic component of the second electrical quantity (the voltage in the example), at the input and / or at the output.

[0060] The measuring device may also comprise, for example between the measuring circuit and the filtering device, a signal conditioning device configured to adapt, by an appropriate proportionality coefficient, the amplitude of the measured signals and provide measured signals conditioned in a predetermined amplitude range, for example the 0-3 V range, adapted to the filtering device.

[0061] Then, in a conventional manner, the calculation device calculates the impedance at a given frequency from the first electrical quantity (the current here) and the second electrical quantity (the voltage here), for example by applying a calculation method based on a Discrete Fourier Transform (DFT) or a Fast Fourier Transform (FFT). An impedance can be calculated for each harmonic frequency.

[0062] The disturbance circuit CP can be configured to provide a disturbance waveform comprising a plurality of harmonic components, each at a predefined frequency; in this case the processing means is preferably configured to determine an input impedance or an output impedance for the predefined frequency of each component. Depending on the frequency requirements to be tested, the disturbance circuit can thus produce a disturbance waveform comprising a single frequency such as a sinusoidal waveform, or a waveform comprising several harmonic components such as a triangular, square, etc. waveform. In a concrete implementation example, the disturbance circuit can be a digital current source, capable of generating a digital signal whose amplitude is sufficient to generate a disturbance at the output of the converter.

[0063] The disturbance circuit CP may further be arranged to produce a plurality of disturbance waveforms each comprising one or more harmonic components at one or more predefined frequencies, each disturbance waveform being supplied to a single conversion arm; in this case, the processing means is configured to determine an input impedance or an output impedance for each predefined frequency of each disturbance waveform.Adding several disturbance waveforms, each associated with a conversion arm, and each preferably having harmonic frequencies distinct from the harmonic frequencies of the other disturbance waveforms, makes it possible to limit the risks of having on a conversion arm, even punctually, a disturbance of amplitude too large compared to the amplitude of the power signal (defined by lin, Vin) passing through the conversion arm and transferring the electrical power to the output device. This limits the risks of loss of regulation in a conversion arm of the converter.

[0064] Also, to further limit the disturbance of the regulation simultaneously on several BCx conversion arms, the disturbance circuit is configured to produce several disturbance waveforms out of phase with respect to each other, preferably phase shifted by an angle of 360 / n degrees.

[0065] For a converter according to the invention, the choice of the number n of conversion arms in parallel is a compromise between:

[0066] - the complexity of the converter, which increases with the number of conversion arms in parallel,

[0067] - the efficiency of the converter, which also increases with the number of conversion arms: the greater the number of conversion arms and the less effect a disturbance on one conversion arm has on the entire converter, the lower the risk of regulation failure in the converter. In practice, tests carried out with different numbers n have shown that a converter with n equal to four (4) branches is a good compromise and gives satisfactory results. With a converter with 4 conversion arms, the most interesting results were obtained with a disturbance circuit arranged to produce four disturbance waveforms, the second, third and fourth waveforms being phase-shifted by 90°, 180° and 270° respectively with respect to the first disturbance waveform.

[0068] In practice also, apart from the voltage or current measurement circuits, most of the elements (A / D converter, subtractors, filtering device, calculation circuit, etc.) which make up the MRO, MRI, ..., ... MRx, ..., MRn regulation devices and the means for determining an impedance are digital means; implemented for example from a known DSP (Digital Signal Processor) type processor and programs or portions of computer programs configured to carry out the technical functions sought for these devices.

[0069] Figure 4 shows as an example results obtained for measurements carried out on a converter according to the invention used for charging a LiFePO4 type accumulator battery - 45 A. h from a source consisting of a 5 KW power fuel cell. The converter comprises n = 4 identical conversion arms BC1 to BC4 associated in parallel between the input IN and the output OUT of the converter, according to the diagram in Figure 1. Each conversion arm is of the step-up type such as that of Figure 2. The converter is controlled by PWM signals RC1, ...., RCx, ...., RCn with a switching frequency of 250 kHz. The converter provides the load with a continuous charging current lout of the order of 25 A, with a residual oscillation of the order of 1.5 App (for Ampere Peak to Peak or Ampere peak to peak) at the switching frequency.As explained above, in the converter, the MRO regulation control means and the MRI, ..., MRn regulation devices of the conversion arms ensure the regulation of the quantity lout so that it is adapted to the output device (here a battery) and as stable as possible over time.

[0070] A PI disturbance waveform, here sinusoidal, is applied to the conversion arm BC1 and more precisely to the subtractor 22. The disturbance is taken into account by the correction device 23 which modifies the control signals RC1 accordingly. The modification of the signals RC1 then results in a modification of the current lout_l produced by the conversion arm BC1. The modification of the current lout_l affects the current lout = lout_l + .... + lout_n supplied to the output device. The voltage across the output device changes as a function of the current lout and the intrinsic characteristics of the output device. The modifications of the output electrical quantities lout, Vout are reflected on the input electrical quantities lin, Vin via the regulation means.

[0071] Figure 4a shows:

[0072] - the current lin_l flowing in the input inductance of the conversion circuit CCI of the conversion arm BC1 on which the PI disturbance is applied: the current I in_l is a direct current of approximately 15 A on which a sinusoidal oscillation of amplitude approximately 10 App is superimposed.

[0073] - the currents lin_2, 1 in_3 and lin_4, identical, flowing in the input inductance of the conversion circuits CC2, CC3 and CC4 of the conversion arms BC2, BC3 and BC4, (not disturbed by PI): the current is a direct current of approximately 15 A, with a residual oscillation of the order of 1.5 App at the switching frequency. The switching frequency being very high compared to the frequency of the PI disturbance, the graphical representation of the current I in_2 here results in a band with a mid-value of approximately 15 A and an amplitude of 1.5 App.

[0074] It can be noted that the currents I in_2, I n_3 and I in_4 were not or very little disturbed by the PI disturbance, only the current lin_l undergoing the PI disturbance.

[0075] Figure 4b shows the evolution of the converter's input electrical quantities:

[0076] - the current lin is equal to the sum of the currents flowing in the input inductance of the conversion circuit of each conversion arm BC1 to BC4. Thus, lin has a direct component of the order of 60 A on which is superimposed an alternating component of approximately 10 to 12 App, brought by the PI disturbance via the current l_in_l;

[0077] - the voltage Vin here has a continuous component of the order of 45 V on which is superimposed a very weak alternating component, of the order of 5 Vpp (Volt peak to peak).

[0078] Figure 4c shows the evolution of the converter's output electrical quantities:

[0079] - the current lout is equal to the sum of the currents produced by the conversion circuits CCI to CC4 of each conversion arm BC1 to BC4. lout here has a direct component of the order of 25 A on which is superimposed an alternating component of approximately 2 App, provided by an alternating component of the same amplitude present on the current lout_l supplied by the conversion arm on which the PI disturbance is applied,

[0080] - the voltage Vout here has a direct component of the order of 100 V, on which is superimposed an alternating component of approximately 8 Vpp.

[0081] After filtering the DC components of the Vin, lin signals, the input impedance of the converter at the PI disturbance frequency can be calculated. Similarly, after filtering the DC components of the Vout, lout signals, the output impedance of the converter at the PI disturbance frequency can be calculated.

[0082] In summary, the invention proposes a new power converter particularly suitable for a non-linear electrochemical charge, and a conversion system comprising a non-linear electrochemical energy source and a converter, converter and conversion system which provide in particular the following technical and economic benefits:

[0083] - continuous regulation of the power transfer between the source and the output device,

[0084] - impedance measurement means allowing real-time monitoring of the operation of the source and the load, without the addition of additional means and without disturbing the operation of the converter. Nomenclature

[0085] S, DS electrical energy source and electrical energy storage element

[0086] IN, OUT input terminal and output terminal of the converter lin first electrical quantity (current in the example) input

[0087] I i n_x fraction of the first electrical input quantity on the conversion arm x

[0088] I *in expected value of the first electrical input quantity

[0089] I *in_x expected value of the fraction of the first electrical input quantity on the conversion arm xl°in_x measured value of the fraction of the first electrical input quantity on the conversion arm x

[0090] Vin second electrical quantity (voltage in the example) of input lout first electrical quantity (current in the example) of output lout_x fraction of the first electrical quantity of output

[0091] Vout second electrical quantity (voltage in the example) output

[0092] V*out expected value of the second electrical output quantity

[0093] V°out measured value of the second electrical output quantity n number of regulated conversion arms

[0094] BC1, ...BCx, ... BCn n regulated conversion arms

[0095] RCx regulation control signals

[0096] CCI, Ccx, CCn conversion circuit

[0097] MRI, ...MRx, ...MRn regulation devices, one per conversion circuit

[0098] 21 device for measuring the fraction of rank x of the 1st electrical input quantity (lin_x)

[0099] 22 subtractor

[0100] 23 correction device

[0101] MRO means of regulation control

[0102] 11 device for measuring the second electrical output quantity (Vout)

[0103] 12 subtractor

[0104] 13 correction device

[0105] Ml means to determine an impedance

[0106] CP disturbance circuit processing means device for measuring input quantities (Vin, lin) and / or output quantities (Vout, lout) measuring circuit continuous component filtering device conditioning device impedance calculation device

Claims

DEMANDS 1. Electronic power converter adapted for transferring energy from an electrical energy source (S) such as an electrochemical power generation source to an output device (DS) such as an electrochemical energy storage device, converter configured to receive on an input terminal (IN) first and second electrical input quantities (lin, Vin, ) of current and voltage supplied by the source and configured to supply on an output terminal (OUT) of the converter first and second electrical output quantities (lout, Vout) of current and voltage adapted to the output device, converter comprising n regulated conversion arms connected in parallel between the input terminal IN and the output terminal OUT of the converter, n being an integer greater than or equal to two,each conversion arm (BCx) being configured to receive from the source a fraction (I in_x) of the first electrical input quantity, to control said fraction of the first electrical input quantity (lin_x) to the second electrical output quantity (Vout) and to supply to the output device a fraction (lout_x) of the first electrical output quantity (lout) adapted to the output device, converter also comprising means for determining an impedance, said means for determining impedance comprising:, - a perturbation circuit arranged to produce and supply to an input of a conversion arm (BCx) a perturbation waveform (Px) comprising a harmonic component at at least one predefined frequency - a processing means configured to measure the electrical input quantities (lin, Vin) of the converter and determine an input impedance of the converter at the predefined frequency as a function of the measured values ​​of the electrical input quantities and / or to measure electrical output quantities (lout, Vout) of the converter and determine an output impedance of the converter at the predefined frequency as a function of the measured values ​​of the electrical output quantities.

2. converter according to claim 1 in which each conversion arm comprises control means (CCx, MRx) configured to measure a value (l°in_x) of said fraction of the first electrical input quantity (lin_x) and configured to control said fraction (I in_x) of the first electrical input quantity as a function of the measured value (l°in_x) of said fraction of the first electrical input quantity and of the second electrical output quantity (Vout).

3. Converter according to claim 2 comprising a configured control and regulation (MRO) means: - to measure a value (V°out) of the second electrical output quantity (Vout), - to determine, for each rank x conversion arm (BCx), an expected value (I *in_x) of a rank x fraction of the first input electrical quantity (lin) as a function of an offset (V*out - V°out) between an expected value (V*out) of the second output electrical quantity (Vout) and the measured value (V°out) of said second output electrical quantity (Vout), and - to provide the expected value of rank x (I *i n_x) of the rank x fraction (lin_x) of the first electrical input quantity (lin) to each rank x conversion arm, and converter in which the control means of each rank x conversion arm (BCx), x being a number between 1 and n, comprises: - a control device (MRx) configured to produce control signaling signals (RCx) based on an offset (I * in_x - I n_x) between the expected value (I * in_x) of the x-th fraction of the first input electrical quantity (lin) and the received value from the source of the x-th fraction (I in_x) of the first input electrical quantity (lin), and - a conversion circuit (CCx) arranged to produce the fraction of rank x (lout_x) of the first electrical output quantity (lout) as a function of the control regulation signals.

4. Converter according to claim 3 in which the perturbation circuit is configured to superimpose the perturbation waveform (Px) on the expected value (I *in_x) of the rank fraction x of the first electrical quantity (lin) input.

5. Converter according to any one of the preceding claims, in which n is equal to four.

6. Converter according to any one of the preceding claims, wherein, in the means for determining an impedance, the processing means comprises: - a device for measuring the first and second electrical input quantities (lin, Vin) of current and voltage, and / or a device for measuring the first and second electrical output quantities (lout, Vout) of current and voltage, - a filtering circuit for the measured quantities to filter out a DC component of said measured quantities, and - a calculation circuit configured to determine an input impedance of the converter at the predefined frequency based on the measured values ​​of the input electrical quantities and / or configured to determine an output impedance of the converter at the predefined frequency based on the measured values ​​of the output electrical quantities.

7. Converter according to claim 6, wherein the disturbance circuit is configured to provide a disturbance waveform comprising a plurality of harmonic components at a plurality of predefined frequencies, and wherein the processing means is configured to determine an input impedance or an output impedance for each predefined frequency.

8. Converter according to any one of the preceding claims, wherein: - the perturbation circuit is arranged to produce several perturbation waveforms, each comprising one or more harmonic components at one or more predefined frequencies, each perturbation waveform being supplied to a single conversion arm, and in which - the processing means is configured to determine an input impedance or an output impedance for each predefined frequency of each disturbance waveform.

9. Converter according to the preceding claim in which the disturbance circuit is configured to produce disturbance waveforms out of phase with respect to each other by an angle of 360 / n degrees.

10. Converter according to the preceding claim, wherein n is equal to four, and wherein the disturbance circuit is arranged to produce four disturbance waveforms, a second, a third and a fourth waveform being phase-shifted by 90°, 180° and 270° respectively with respect to a first waveform.

11. Energy transfer system comprising, connected in series, an electrical energy source such as an electrochemical source for the production of electrical energy and a converter according to one of the preceding claims, an input terminal IN of the converter being connected to an output terminal of the source, and an output terminal of the converter being intended to be connected to an input terminal of an output device such as an electrochemical energy storage device.

12. Hybrid system comprising an energy transfer system according to the preceding claim, an output terminal of the converter being connected to an input terminal of an output device such as an electrochemical energy storage device.

Images