METHOD FOR VERIFYING THE CONFORMITY OF AN ELECTRICAL POWER CONVERTER

Abstract

The method comprises the steps of: a) (SF1) determining, for a plurality of converter operating points (P11, …P1n, …P1N) and parameter values ​​(PD1), a maximum power command (Fmax) and a minimum power command (Fmin) representative of the upper and lower power command limits between which the converter gain curve is considered to conform to nominal characteristics, and storing these maximum and minimum commands for the plurality of operating points and parameter values; b) (SF2) during converter operation, for several operating points and parameter values, comparing an effective converter power command (Fe) to the corresponding stored maximum and minimum commands and detecting overshoots (DFmax, DFmin); and c) (SF3) deciding on conformity (INf_CF1) based on the detected overshoots. Figure 1

Description

Title of the invention: METHOD FOR VERIFYING THE CONFORMITY OF AN ELECTRICAL POWER CONVERTER

[0001] The present invention relates generally to the field of electrical power converters. More particularly, the invention relates to a method for verifying the conformity of the gain curve of an electrical power converter.

[0002] Electrical power converters are essential components for the energy transformation of our societies towards a low-carbon economy. Thus, the transport sector, which is the source of a significant proportion of polluting emissions and greenhouse gas emissions, is experiencing increasing electrification of the various transport systems, and significant technological developments in the field of electrical power conversion.

[0003] Electrical converters of various types are integrated, as essential functional components, in electrified motor vehicles, of hybrid and all-electric types, as well as in electrical charging systems such as electrical charging stations and robots, of the conduction (wired) or electromagnetic induction type. Electrical power supply networks, in particular those dedicated to electric mobility, will in the future integrate a greater number of electrical power converters for their connection to the future intelligent electrical network, known as "smart grid" in English.

[0004] Optimizing energy performance and the functional availability of equipment requires effective preventive maintenance of electrical power converters.

[0005] In the state of the art, it is known to monitor the temperature of certain critical components of a converter during operation and to apply a degraded mode, or to diagnose a breakdown, when the measured temperature is excessive. It is also known to monitor the input electrical voltage of the converter during operation. The conformity of the converter with expected nominal characteristics is verified in the factory, at the end of the manufacturing line.

[0006] Studies, simulations and tests carried out by the inventive entity have highlighted the benefit of verifying during operation the conformity of an electrical power converter with one or more expected performances thereof. Verifying conformity during operation has appeared to be a useful tool for detecting breakdowns early, or even anticipating them, at benefit from effective preventive maintenance, and for better functional management of the converter, for example, by adapting the applied control strategy.

[0007] The present invention aims to provide a new method for verifying the conformity of the gain curve of an electrical power converter, this method being able to be implemented not only in the factory, at the end of manufacture of the converter, but also throughout the life of the converter, in different life phases, including in real time during operating phases.

[0008] According to a first aspect, the invention relates to a method for verifying the conformity of a gain curve of an electrical power converter.According to the invention, the method comprises the steps of: a) determining, for a plurality of predetermined operating points of the converter and predetermined parameter values, a maximum power command and a minimum power command representative of upper and lower power control limits between which the gain curve is considered to be in conformity with nominal gain curve characteristics, and storing the maximum and minimum power commands for the plurality of operating points and parameter values; b) during operation of the converter, for several of the operating points and parameter values, comparing an actual power command of the converter with the corresponding stored maximum and minimum power commands and detecting overshoots; and c) deciding conformity from the detected overshoots.

[0009] According to a particular embodiment, for verifying the conformity of a gain curve of an electrical power converter of the frequency-controlled type, the maximum, minimum and effective power commands are frequency power commands.

[0010] According to a particular characteristic, for an electrical power converter of the frequency-controlled type, the predetermined parameters comprise one or more parameters from among an input current, an output current, an input voltage, an output voltage, an output load, a temperature, and a fixed duty cycle.

[0011] According to another particular embodiment, for the verification of conformity of a gain curve of an electrical power converter of the type controlled by the duty cycle, the maximum, minimum and effective power commands are power commands by the duty cycle.

[0012] According to a particular characteristic, for an electrical power converter of the type controlled by the duty cycle, the predetermined parameters comprise one or more parameters from among an input current, an output current, a voltage input, output voltage, output load, temperature, and fixed working frequency.

[0013] The invention also relates to an electrical power converter comprising an electronic power circuit and a control computer, in which the control computer comprises a memory storing program instructions for implementing the method briefly described above.

[0014] According to a particular embodiment, the converter is of the power factor correction type, called “PFC”, and / or of the direct current connection type, called “DC / DC”, and / or of the direct-alternating inverter type, called “DC / AC”.

[0015] The invention also relates to an electrified vehicle, an electric charging station for an electrified vehicle and an electric charging robot for an electrified vehicle comprising an electric power converter as indicated above.

[0016] Other advantages and characteristics of the present invention will appear more clearly on reading the detailed description below of several particular embodiments of the invention, with reference to the appended drawings, in which:

[0017] [Fig. 1] is a flowchart illustrating a particular embodiment of the method according to the invention.

[0018] [Fig.2] is another flowchart illustrating another particular embodiment of the method according to the invention.

[0019] [Fig. 3] is a block diagram of a particular embodiment of an electrical power converter in which the method according to the invention is implemented.

[0020] Generally speaking, the method of the invention is applicable for verifying the conformity of one or more gain curves of an electrical power converter, as a function of internal and external parameters having an influence on this curve, such as for example the temperature, the output load of the converter, its working frequency, the applied input voltage, the output voltage of the converter, the drifts of certain components and others. By gain curve of the electrical power converter, we will understand a voltage gain curve or a current gain curve thereof.

[0021] The method of the invention makes it possible to verify that the converter provides a gain curve in accordance with the nominal characteristics thereof, those defined during the design of the converter. This gain curve depends in particular on the design choices of the internal architecture of the converter, essentially relating to the inductance, the capacitor and the electronic power switches (typically "MOSFET" transistors) included in the converter, the type of cooling and others, as well as external parameters, such as temperature, voltage, current and others, and internal parameters such as the tolerances on ca- characteristics of components and drifts.

[0022] Thus, taking into account the known tolerances and drifts on the components, it is possible to theoretically determine maximum and minimum gain values ​​as a function of dimensioning parameters such as temperature, voltage, current and others. When the effective gain value is between the aforementioned maximum and minimum gain values, the converter is compliant. Otherwise, the converter is not compliant.

[0023] Depending on whether the electrical power converter is of the type having a frequency power control (with a fixed duty cycle) or a power control by the duty cycle (with a fixed frequency), the maximum and minimum gain values ​​which have been determined as indicated above correspond to maximum and minimum theoretical control frequencies or maximum and minimum theoretical control duty cycles, respectively. These maximum and minimum theoretical control frequencies, or maximum and minimum theoretical control duty cycles, are representative of upper and lower power control limits between which, for a considered operating point and current values ​​of the dimensioning parameters, the gain curve is considered to be in accordance with the nominal characteristics of the gain curve defined during the design of the converter.Thus, in accordance with the invention, for the conformity check, the effective control frequency for each operating point considered is compared with the corresponding maximum and minimum theoretical control frequencies, or the effective control duty cycle with the corresponding maximum and minimum theoretical control duty cycles, depending on the type of power control. A conformity decision is then taken on the basis of the detected overshoots.

[0024] [Fig. 1] illustrates a first example of embodiment of the method of the invention for verifying a voltage gain curve Gv=Vs / Ve of a frequency-controlled converter, of the resonant type, with Vs and Ve being respectively the output voltage and the input voltage of the converter.

[0025] As visible in [Fig. 1], the method here essentially comprises three main steps SF1 to SF3.

[0026] The method considers different operating points Pli, ...Pin, ...PIN of the converter to which correspond pairs of input and output voltages (Vel, Vsl), ... (Ven, Vsn), ... (VeN, VsN) determining gain values.

[0027] Step SF1 is a step prior to the actual conformity check. In this step SF1, for the different operating points considered P1, ... P1, ... P1N of the converter, maximum and minimum theoretical control frequencies, Fmax and Fmin, are determined, taking into account the tolerances and drifts, depending on PDI dimensioning parameters, such as the input and output voltages Ve and Vs of the converter, the output load LD of the converter, the temperature T, the fixed duty cycle RC of the converter and others if applicable. The determined values ​​of control frequencies Fmax and Fmin are stored in memory, for example in the form of a multidimensional map CATL

[0028] Step SF2 is a step of taking measurements and comparing for the different operating points Pli, ... Pin, ... PIN intended to collect data for a decision on the conformity of the gain curve Gv of the converter.For each operating point considered Pin, the processing process implementing the method of the invention reads the current value of the effective control frequency Fe and retrieves from the aforementioned CAT1 map the theoretical frequencies Fmax and Fmin corresponding to the current values ​​of the PDI dimensioning parameters for the operating point Pin. The effective frequency Fe is compared with the theoretical frequencies Fmax and Fmin. The overshoots by the effective frequency Fe of the maximum and minimum theoretical frequencies Fmax and Fmin are indicated by overshoot information DFmax and DFmin, respectively. The overshoot information DFmax, DFmin, are the data used for the decision on the conformity of the gain curve Gv of the converter.

[0029] In step SF3, the processing process uses the overshoot information DFmax, DFmin, collected in step SF2, so as to decide on the conformity or non-conformity of the gain curve Gv. Different decision methods may be used depending on the application. Thus, for example, a non-conformity decision may be taken on the basis of the amplitude of the overshoots, the number of overshoots over a predefined duration or on another basis, by using the information DFmax, DFmin. The information INF_CF1 provided by step SF3 indicates the conformity or non-conformity of the gain curve Gv of the converter.

[0030] [Fig.2] illustrates a second example embodiment of the method of the invention for verifying a current gain curve Gc=Is / Ie of a converter controlled by the duty cycle, with Is and Ie being respectively the output current and the input current of the converter.

[0031] As visible in [Fig.2], the method here essentially comprises three main steps SRI to SR3.

[0032] The method considers different operating points P21, ... P2n, ... P2N of the converter to which correspond pairs of input and output currents (lel, Isl), ... (len, Isn), ... (leN, IsN) determining gain values.

[0033] The SRI step is a step prior to the actual conformity check. In this SRI step, for the different operating points considered P21, ... P2n, ... P2N of the converter, duty cycles are determined. theoretical maximum and minimum control, RCmax and RCmin, taking into account tolerances and drifts, according to dimensioning parameters PD2, such as the input and output currents Ie and Is of the converter, the output load LD of the converter, the temperature T, the fixed working frequency F of the converter and others if applicable. The determined values ​​of control duty cycles RCmax and RCmin are stored in memory, for example in the form of a multidimensional map CAT2.

[0034] Step SR2 is a measurement collection and comparison step for the different operating points P21, ... P2n, ... P2N intended to collect data for a decision on the conformity of the gain curve Gc of the converter. For each operating point considered P2n, the processing process implementing the method of the invention reads the current value of the effective control duty cycle RCe and retrieves from the aforementioned CAT2 map the theoretical duty cycles RCmax and RCmin corresponding to the current values ​​of the dimensioning parameters PD2 for the operating point P2n. The effective duty cycle RCe is compared with the theoretical duty cycles RCmax and RCmin. Exceedances by the effective duty cycle RCe of the maximum and minimum theoretical duty cycles RCmax and RCmin are indicated by exceedance information DRmax and DRmin, respectively.The DRmax, DRmin overshoot information is the data used for the decision on the conformity of the converter gain curve Gc.

[0035] In step SR3, the processing process uses the DRmax, DRmin overshoot information collected in step SR2, so as to decide on the conformity or non-conformity of the gain curve Gc. Different decision methods may be used depending on the application. Thus, for example, a non-conformity decision may be taken on the basis of the amplitude of the overshoots, the number of overshoots over a predefined duration or on another basis, by using the DRmax, DRmin information. The INF_CF2 information provided by step SR3 indicates the conformity or non-conformity of the gain curve Gc of the converter.

[0036] With particular reference to [Fig. 3], a particular embodiment PW_CONV of an electrical power converter is now described in which the method of the invention is implemented. The converter PW_CONV is considered here as being a voltage converter controlled by the duty cycle.

[0037] As visible in [Fig.3], the electrical power converter PW_CONV produces a regulated output voltage Vs from an input voltage Ve. The converter PW_CONV essentially comprises a control computer ECU and a power electronic circuit CONV integrating at least one inductor, a capacitor and an electronic power switch (not shown).

[0038] The ECU control computer comprises a memory MEM in which a control software module CTRL_CONV and a conformity management software module MGT_CF are housed.

[0039] The CTRL_CONV control software module is responsible for controlling the switching operations in the CONV power electronic circuit. The CTRL_CONV module typically applies several control strategies depending on the life situation of the PW_CONV converter. The CTRL_CONV module provides one or more CTRL_SW switching control signals for controlling the CONV power electronic circuit. The CTRL_SW switching control signals have an effective duty cycle RCe which is determined using at least one control loop (not shown) to regulate the output voltage Vs of the PW_CONV converter.The CTRL_CONV module receives various input information to perform its function, such as an output voltage setpoint Cons_Vs and effective output voltage and load information Inf_Vs and Inf_LD, as well as other information such as the input voltage Inf_Ve, the fixed working frequency Inf_F and the temperature T. .

[0040] The MGT_CF compliance management software module is dedicated to the implementation of the method of the invention. The execution of code instructions of the MGT_CF module by the ECU calculator allows the implementation of the method of the invention for verifying the compliance of the gain curve (here, Gv=Vs / Ve) of the PW_CONV power electrical converter.

[0041] In this exemplary embodiment, the MGT_CF module notably comprises a CART mapping, comparators C1, C2, and a CF decision function.

[0042] The CART mapping is here a multidimensional mapping which includes data of maximum and minimum theoretical duty cycles Inf_RCmax, Inf_RCmin, for different operating points PI, ... Pn, ... PN of the converter, as a function of dimensioning parameters PD, such as the input and output voltages of the converter, its output load, its fixed working frequency F, and the temperature T, provided here respectively by the information Inf_Ve, Inf_Vs, Inf_LD, Inf_F and Inf_T.

[0043] The comparators C1, C2 are responsible for comparing effective duty cycle information Inf_RCe with the maximum and minimum theoretical duty cycle information Inf_RCmax, Inf_RCmin, for each operating point Pn. Thus, the information Inf_RCe provided by the module CTRL_CONV is compared with the information Inf_RCmax and the information Inf_RCmin. These comparisons make it possible to detect overshoots, informed by overshoot information Inf_DRmax and Inf_DRmin which are provided to the decision function CF.

[0044] The decision function CF uses the overshoot information Inf_DRmax and Inf_DRmin corresponding to different operating points Pn so as to decide on the conformity or non-conformity of the gain curve Gv of the converter. A conformity information INF_CF is provided by the decision function CF and indicates the conformity or non-conformity of the gain curve Gv of the converter. The information INF_CF is used in particular for early detection of failures and preventive maintenance. In addition, as shown in [Fig.3] for this exemplary embodiment, the information INF_CF can also be used by the control module CTRL_CONV to adapt the applied control strategy, for example, by selecting a degraded mode.

[0045] Generally speaking, the invention is applicable for the management of compliance of the gain curve of different types of electrical power converters. Thus, the converter may be of the “alternating / direct” type called “AC / DC”, of the “direct / direct” type called “DC / DC”, of the “direct / alternating” type called “DC / AC”, or even of the “alternating / alternating” type called “AC / AC”. The functional architecture of the electrical power converter may in particular be of the so-called “BUCK” type, of the so-called “BOOST” type, of the so-called “BUCK-BOOST” type, of the so-called “CUK” type or of the so-called “SEPIC” type, but not exclusively.

[0046] More particularly, the implementation of the method of the invention will be particularly advantageous in an electrical power converter of the power factor correction type, called “PFC” (for “Power Factor Correction” in English), as well as in an electrical power converter of the direct current link type, called “DC / DC”, and an electrical power converter of the direct-alternating inverter type, called “DC / AC”.

[0047] The invention provides a simple, easy-to-implement solution for early detection of possible failures in electrical power converters. It makes it possible to improve the availability of the converters and to increase the lifespan of their components. The method of the invention may be implemented in different phases of the life of an electrical power converter, typically in the factory, at the end of its manufacture, and throughout its life, for example at each power-up, but also in real time during operating phases, and other moments of life, depending on the applications.

[0048] The electrical power converters in which the method of the invention is implemented can be integrated into a large number of equipment and systems, and in particular into electrified vehicles, of the hybrid and all-electric types, as well as the electric charging terminals and robots for these vehicles.

[0049] The invention is not limited to the particular embodiments which have been described here by way of example. In general, a person skilled in the art, depending on the applications of the invention, may make various modifications and variations falling within the scope of protection of the invention.

Claims

1.

2.

3. Claims Method for verifying the conformity of a gain curve (Gv, Gc) of an electrical power converter (PW_CONV), characterized in that it comprises the steps of: a) (SF1, SRI) determining, for a plurality of predetermined operating points (Pli, ...Pin, ...PIN; P21, ...P2n, ...P2N; P1, ...Pn, ...PN) of said converter (PW_CONV) and predetermined parameter values ​​(PDI, PD2, PD), a maximum power command (Fmax, RCmax, Inf_RCmax) and a minimum power command (Fmin, RCmin, Inf_RCmin) representative of upper and lower power control limits between which said gain curve is considered to be in conformity with nominal gain curve characteristics, and storing said maximum (Fmax, RCmax, Inf_RCmax) and minimum (Fmin, RCmin, Inf_RCmin) power commands for the plurality of said operating points (Pli, ...Pin, ...PIN; P21, ...P2n, ...P2N; PI, ...Pn, ...PN) and parameter values ​​(PDI, PD2, PD); b) (SF2, SR2) during operation of said converter (PW_CONV), for several of said operating points (Pli, ...Pin, ...PIN; P21, ...P2n, ...P2N; PI, ...Pn, ...PN) and parameter values ​​(PDI, PD2, PD), compare an effective power command (Fe, RCe, Inf_RCe) of said converter (PW_CONV) with said corresponding stored maximum (Fmax, RCmax, Inf_RCmax) and minimum (Fmin, RCmin, Inf_RCmin) power commands and detect overshoots (DFmax, DFmin; DRmax, DRmin;. Inf_DRmax, Inf_DRmin); and c) (SF3, SR3) decide on said conformity (INF_CF1, INF_CF2, INF_CF) from said detected excesses (DFmax, DFmin; DRmax, DRmin; Inf_DRmax, Inf_DRmin). Method according to claim 1, for verifying the conformity of a gain curve of an electrical power converter of the frequency-controlled type, characterized in that said maximum, minimum and effective power commands (Fmax, Fmin, Fe) are frequency power commands. Method according to claim 2, characterized in that said predetermined parameters comprise one or more parameters from among an input current (Ie), an output current (Is), an input voltage (Ve), an output voltage (Vs), an output load (LD), a temperature (T), and a fixed duty cycle (RC).

4. Method according to claim 1, for verifying the conformity of a gain curve of an electrical power converter of the type controlled by the duty cycle, characterized in that said maximum, minimum and effective power controls (RCmax, RCmin, RCe) are power controls by the duty cycle.

5. Method according to claim 4, characterized in that said predetermined parameters comprise one or more parameters among an input current (Ie), an output current (Is), an input voltage (Ve), an output voltage (Vs), an output load (LD), a temperature (T), and a fixed working frequency (F).

6. Electrical power converter (PW_CONV) comprising a power electronic circuit (CONV) and a control computer (ECU), characterized in that said control computer (ECU) comprises a memory (MEM) storing program instructions (MGT_CF) for implementing the method according to any one of claims 1 to 5.

7. Electrical power converter according to claim 6, characterized in that it is of the power factor correction type, called “PFC”, and / or of the direct current connection type, called “DC / DC”, and / or of the direct-alternating inverter type, called “DC / AC”.

8. Electrified vehicle, characterized in that it comprises an electric power converter (PW_CONV) according to claim 6 or 7.

9. Electric charging station for an electrified vehicle, characterized in that it comprises an electric power converter (PW_CONV) according to claim 6 or 7.

10. Electric recharging robot for an electrified vehicle, characterized in that it comprises an electric power converter (PW_CONV) according to claim 6 or 7.

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