Method for energy management of hybrid energy storage devices

Abstract

The present invention relates to a method for energy management of a hybrid energy storage device in a stationary or mobile system, in order to allow optimal sizing of said system, the hybrid energy storage device comprising at least one main energy source such as a battery, at least one auxiliary energy source such as a super-capacitor, and at least one converter.

Description

[0001] METHOD FOR ENERGY MANAGEMENT OF HYBRID ENERGY STORAGE DEVICES

[0002] Technical field of the invention

[0003] The field of the invention is that of energy management algorithms for energy storage devices and falls within the scope of improving the sizing, performance and lifetime of such devices. More particularly, these are energy management strategy algorithms (usually known as "Energy Management Strategy" and designated by the English acronym EMS), these algorithms being intended for the energy management of storage systems of the Li-ion battery / supercapacitor (SC) type.

[0004] Technical background

[0005] In any engineering problem, dimensioning is crucial in product design. It allows defining and estimating the dimensions, volume, mass, cost of an object or any other technical characteristics based on specifications. The latter will allow the operating point(s) to be determined, as well as the system constraints. Thus, from a certain number of more or less complex calculations, a more or less precise estimate can be given as to the dimensions of the materials or the number of components that must be used. This dimensioning step is essential because it provides a methodology when designing an object, thus saving significant time and money. Usually, dimensioning is coupled with modeling. The latter allows the object to be digitally recreated based on the dimensioning carried out and its operation to be verified.Slight adjustments can then be made to the modeling to correct the various discrepancies.

[0006] In the case of a hybrid energy storage device with at least one main energy source and at least one auxiliary energy source, and in particular a hybrid source of the Li-ion battery / supercapacitor type with semi-active architecture on the supercapacitor side, it is the battery, the supercapacitors as well as the converter (which is a power converter) which must be sized.

[0007] In the rest of the text, supercapacitors will be referred to by the acronym SC usually used in this technical field.

[0008] In the scientific literature, we find different sizing methods. Thus, Araujo [1]proposes for example an optimization algorithm coupled with energy management in order to determine the number of battery cells and SC. A rule-based energy management strategy (designated by the acronym SGE) (strategy according to a frequency method), as well as an optimization problem are used. However, in addition to being dedicated to an active architecture, this method does not take into account the real-time nature of the SGE for the optimization-based method. Zhang [2] uses wavelet transforms in its sizing to define the power sharing. It then considers mass, cost and the state of health (SOH) of the battery as objectives in its sizing algorithm. To converge, a genetic algorithm (NSGA-II) is used. Gonzalez [3]takes into account battery degradation in order to size the energy storage devices of the hybrid source. Ostadi [4] uses a particle swarm optimization algorithm (usually referred to by the acronym PSO) to determine the number of battery cells and SCs. In this study, only the price of the hybrid source is the variable to be minimized. Herrera [5] will also adopt this same idea and apply its dimensioning for a tramway, with a slightly more complex architecture comprising two converter units, both coupled to a supercapacitor module. Xiong [6] uses dynamic programming for the control strategy and uses a second PSO-based optimization loop to determine the parameters of its dynamic programming algorithm. Trieste [7]presents a sizing study of a three-arm interleaved boost converter, as well as the associated supercapacitors. However, there is no information on battery sizing in his study.

[0009] The sizing presented above is generally based on optimization problems coupled with energy management. Indeed, it is unthinkable to dissociate the two, as the efficiency of an EMS influences the performance of a hybrid source. However, in order to respect the real-time nature of the EMS and the embedded system aspect, it is necessary that the algorithm in question is adapted: which is not the case for dynamic programming (DP) for example. It should also be noted that in most existing works, no information concerning the sizing of the converter is mentioned. Moreover, the sizing most often targets active architectures.

[0010] Summary of the invention

[0011] In order to solve the problems and drawbacks of the prior art, the applicants have developed a method for energy management of a hybrid energy storage device (or also referred to by the terms hybrid source in the rest of the text) in a stationary or mobile system, to allow optimal dimensioning thereof, said hybrid energy storage device comprising at least one main energy source, at least one auxiliary energy source, and at least one converter, said method comprising the following steps:

[0012] - A) a first sizing step including:

[0013] Al) the acquisition of the following input parameters: power cycles of said system (in particular speed and dynamic cycles if the system is a vehicle), and the technology of the main and auxiliary energy sources of said hybrid energy storage device, then

[0014] A2) setting up an energy management strategy using a first predictive control MPC1 to obtain the following output data: the sizing data of said main energy source and said auxiliary energy source required and information relating to said at least one converter (and in particular a power converter);

[0015] - B) a second test step in simulation of the consistency of the output data obtained in step A) comprising the following sub-steps:

[0016] Bl) modeling on the one hand of said main energy source and on the other hand of said auxiliary energy source as well as said at least one power converter serving as an interface between said main and auxiliary energy sources;

[0017] B2) controlling said hybrid energy storage device using an algorithm comprising an energy management loop consisting of a second non-linear MPC2 predictive control (designated by the acronym NMPC2).

[0018] For the purposes of the present invention, the term “converter” means a power converter. If the expected performance is not achieved, the sizing data of the energy sources obtained in step A (for example, the number of battery cells and / or supercapacitors for a Li-ion / SC battery hybrid device) are adjusted and then move on to the last step, after adapting the algorithm of step B2.

[0019] With regard to the first step A) of dimensioning and more particularly the sub-step Al) of acquiring the input parameters, within the meaning of the present invention, the term “technology of the different energy sources of the hybrid energy storage device” means the chemistry (for example in the case of a battery) and / or the typology of the energy sources (for example in the case of a super capacitor SC): in particular, the voltage, the capacity and the resistance of each of the energy sources may be mentioned.

[0020] With regard to the first step A) of dimensioning, and more particularly the sub-step A2) of setting up an energy management strategy, within the meaning of the present invention, dimensioning data for the main and auxiliary energy sources means data such as the voltage, capacity and power of the different energy sources.

[0021] In the case of a hybrid device of the li-ion battery / supercapacitor (or SC) type, the dimensioning data of said first energy source (11) and of said auxiliary energy source would notably include the number of cells of the battery and of the SC. Advantageously, the algorithm of step B2 is separated into two parts comprising:

[0022] • a first part consisting of an internal loop to control the power of the auxiliary energy source, and

[0023] • a second part consisting of an external loop made up of said predictive command NMPC2 (different from the first predictive command MPC1).

[0024] Preferably, the external loop can be calibrated (usually the term "tuned" is used in English) in order to optimize the performance of the hybrid source.

[0025] Advantageously, the method according to the invention may further comprise a third optional step C of testing the algorithm of step B2) on a real system. For this third optional step C, the part relating to the computer hardware usable for implementing the algorithm is chosen according to step B.

[0026] Advantageously, each of the main and auxiliary energy sources can be selected from the group consisting of the following energy sources: batteries (in particular Li-ion batteries, sodium batteries, Li-air batteries and Li-solid batteries), fuel cells, supercapacitors and flywheels.

[0027] Preferably, the primary energy source may be a battery, and preferably a battery selected from the group consisting of Li-ion batteries, sodium batteries, Li-air batteries and Li-solid batteries.

[0028] More preferably, the primary power source may be a Li-ion battery and the auxiliary power source a supercapacitor.

[0029] Advantageously, successive iterations can be carried out between steps A) and B) and, where appropriate, between steps B) and C), when the method according to the invention comprises the optional step C. The method according to the invention can be used in an application such as electric mobility.

[0030] For the purposes of the present invention, electric mobility means systems for transporting people or goods (road, air, sea, rail) but also on-board electrical systems (for example, lifting platforms, garbage truck bins, emergency vehicle ladders, etc.), which may or may not be fitted to electric transport systems.

[0031] The method according to the invention can also be used in the field of stationary applications such as photovoltaics and wind power, for the energy management of a hybrid energy storage device (1) in a stationary system.

[0032] Other advantages and features of the present invention will result from the description which follows, given by way of non-limiting example and with reference to the figures and examples.

[0033] Brief description of the figures

[0034] [Fig. 1] - Figure 1 is a schematic representation of the implementation of an EMS type energy management strategy (for “Energy Management Strategy”) known to those skilled in the art;

[0035] [Fig. 2] - Figure 2 is a schematic representation of the implementation of an energy management strategy according to the method according to the invention in the case of a particular example of a hybrid storage device of the Li-ion battery / supercapacitor type.

[0036] [Fig. 3] - Figure 3 comprises two diagrams representing respectively the models used for the predictive control NMPC2 of the battery 11 and the supercapacitors 12, in which the battery is considered as a voltage source in series with a resistor (left part of Figure 3) and the supercapacitors are represented by a capacitor in series with a resistor (right part of Figure 3);

[0037] [Fig. 4] - Figure 4 is a block diagram of the algorithm of sub-step B2) according to the non-linear NMPC2 predictive control;

[0038] [Fig.5] - Figure 5 is a block diagram of the hybrid source control.

[0039] Detailed description of the figures

[0040] Figure 1 schematically represents the implementation of an energy management strategy of the EMS type (for "Energy Management Strategy") known to those skilled in the art. To improve the performance of the batteries, their lifespan as well as their sizing, it is known to associate a High Energy Li-ion battery 110 with a supercapacitor (SC) 120, to obtain in particular an energy storage device 10 with a high specific energy and therefore a long autonomy, and a high specific power and therefore a high dynamic range. One has a high specific energy (long autonomy) while the other has a high specific power (high dynamic range). The two energy sources 110, 111 must be connected together via one or more power converters (not shown in Figure 1) in order to allow active power sharing between the battery 110 and the supercapacitors 111.The hybrid energy storage device 10 shown in FIG. 1 powers a thruster 22.

[0041] Figure 2 is a schematic representation of the implementation of an energy management strategy according to the method according to the invention in the case of a hybrid energy storage device 1 of the Li-ion battery 11 / supercapacitor 12 type with a converter 13.

[0042] In the particular case illustrated in Figure 2, the hybrid energy storage device 1, which is embedded in a mobile device 2, comprises as main energy source a Li-ion battery 11 and a supercapacitor 12 as auxiliary energy source and a power converter 13 interacting with a microprocessor 3 on which is embedded an optimization-based EMS algorithm, based on MPC (“Model Predictive Control”).

[0043] The hybrid energy storage device 1 supplies a system 2 comprising (in the particular case illustrated in FIG. 2) an electric motor 21, a thruster 22 and an inverter 23, this system 2 supplied by the hybrid device 1 constituting the load to which the hybrid device 1 will have to supply power in order to operate.

[0044] Figures 3 to 5, relating respectively to the second predictive control NMPC2 (figure 4) and to the models used for NMPC2 (figure 3) and to a block diagram of the control of the hybrid source 1, are commented on in relation to the method according to the invention. This comprises the following steps:

[0045] - A) a first sizing step including:

[0046] Al) acquiring the following input parameters: the number of battery cells 11 and supercapacitor 12 required and information relating to the power converter 13, and the technology of the battery 11 and supercapacitor 12;

[0047] A2) the implementation of an energy management strategy using a first predictive control MPC1 to obtain the following output data: the sizing data of the battery 11 and the supercapacitor 12 required (number of cells) and information relating to the converter 13; - B) a second test step in simulation of the consistency of the output data obtained in step A) comprising the following sub-steps:

[0048] Bl) modeling on the one hand of the battery 11 and on the other hand of the supercapacitor 12 as well as of the power converter 13 serving as an interface between the battery 11 and the supercapacitor 12;

[0049] B2) controlling said hybrid energy storage device 1 using an algorithm comprising an energy management loop consisting of a second non-linear predictive control NMPC2.

[0050] First step A of sizing

[0051] Acquisition Al) of input parameters

[0052] Power cycles can come from measurements made on the target system to be sized, or they can come from measured or standardized speed cycles. From the speed cycles and the dynamic system model, it is possible to estimate the different power cycles of the system. The different data of the energy storage devices are retrieved from the datasheets of the different components. They can be chosen arbitrarily or defined according to specifications.

[0053] Energy management strategy A2)

[0054] Regarding the implementation of an energy management strategy (step A2) using a first predictive control MPC1, this is based on a simple model to solve the optimization problem. In the context of the present invention, a model described below is used where the energy is nothing other than the integral of the power. A minus sign is added to equations (1) and (2) in order to simulate the behavior of an energy storage device: the energy output reduces the capacity of the energy storage device 1. In the final control of this model, the battery 11 is acted on indirectly to control the hybrid energy storage device according to the invention 1.

[0055] Therefore, the battery power Pbat is the control variable.

[0056] We then seek to express the power P scof said supercapacitor 12 (also designated by the acronym SC), depending on the control variable and P v which is the power demanded by the load, which is considered here as a disturbance variable.

[0057] We note t m , the total duration of the mission.

[0058] We then seek to minimize a cost function (hereinafter referred to as J), in order to allow the supercapacitor 12 (or SC) to recharge at a reference energy on the one hand, and to penalize the Pbat command, which results in the following cost equation (equation (5)):

[0059] The constraints are as follows: with :

[0060] J defining the cost function,

[0061] - N p defining the prediction horizon,

[0062] - Wdi and Wd2 defining the weights of the cost function J,

[0063] - Esc defining the energy of SC 12,

[0064] - Escref defining the reference energy of the SC 12, i.e. the energy to which the SCs must recharge once they have supplied or absorbed energy; the role of the SCs is to act as buffers and must always be able to supply and / or absorb current;

[0065] (k+i |k) corresponds to the predicted value of the variable at time k + i, based on the information at time k,

[0066] - Pbmin and Pbmax, the minimum and maximum limits of battery power 11.

[0067] The variables wai and Wd2 are used to adjust the cost function J by choosing to emphasize one term rather than another. Given the different orders of magnitude between the energy of the SC 12 and the power of the battery 11, i.e. Esc and Pbat, it is necessary to normalize the cost function J using the weights wai and Wd2.

[0068] We choose to normalize the cost function J around 1, so that: (7) with :

[0069] - Pv max defining the maximum power requested by the load corresponding to the system supplied by the hybrid source (and designated in the rest of the description by the load): the load is controlled and the hybrid source will have to supply power to operate the load

[0070] - Early Ev defining the total energy required by the load, and

[0071] - wdl and wd2 defining the weights of the cost function J.

[0072] Having no specific constraints at the sizing level, the power limits of battery 11 remained free. They will nevertheless be taken into consideration during simulation and implementation on the system. Finally, the sampling frequency (Fe) is fixed at 0.5Hz and N p = N c= 20 (with Np designating the prediction horizon and Ne designating the control horizon). The control horizon will be the same as the prediction horizon. The prediction time will therefore be 10 seconds given that the acceleration phases are generally short (around ten seconds). In addition, the acquisition of measurements on embedded systems is generally of the order of a second. The sampling frequency Fe must not be too low for fear of having a value of N p too high and thus encounter an optimization problem that is too complex to solve. As for the load's power demand, it is considered constant in the future when solving the optimization problem (the power demand is not known in advance). Thus, if at time k, a power of 10 kW is measured, the latter will be considered constant from k to k + Np, when predicting and solving the cost function J.

[0073] Second step B) of simulation of the consistency of output data from step A)

[0074] Modeling B 1) of the hybrid source (battery 11 and SC 12)

[0075] When modeling the hybrid source, several elements must be taken into account. The main goal of this step is to confirm the dimensioning of the hybrid source and to certify whether it is truly functional. The aim is to validate the energy operation of the system over one or more speed and power cycles. Thus, the accuracy of the mathematical equations is a determining factor in the choice of the model for each element of the hybrid source. However, the time constants are disparate within the hybrid source itself: for the converter: of the order of a microsecond, for the supercapacitor: of the order of a second, for the battery: of the order of a minute,

[0076] In addition, the time of observation of the speed or power cycle (from twenty minutes to several hours).

[0077] A trade-off must therefore be made between the precision of the results and the calculation time of the simulation.

[0078] Therefore, the modeling of the hybrid source has been oriented towards an energy model of the system, in which power transfers are evaluated more on long time scales (tens of minutes to a few hours) rather than physical behaviors at the converter scale (microsecond).

[0079] In addition, the modeling of the hybrid source is oriented towards control to best translate the behavior of the hybrid source without compromising the calculation speed of energy management strategies (EMS), in particular those based on optimization which are computationally intensive.

[0080] B2) control of said hybrid energy storage device 1

[0081] Step B2 of controlling said hybrid energy storage device 1 is carried out using an algorithm comprising an energy management loop consisting of a second non-linear predictive control NMPC2. Indeed, due to the different non-linearities of the entire energy storage device 1 (converter, battery), a simple linearization around an operating point would not allow for the best results. In addition, the algorithm used will make it possible to take into account the voltage drop of the battery and the SCs, linked to their internal resistance. The Golchoubian study [9]describes a comparison between a linearized MPC and an NMPC and demonstrates the advantage of the latter (less battery demands). This study considers the battery as a voltage source in series with a resistor and the supercapacitors are represented by a capacitor in series with a resistor (Figure 3). The states of the model are the state of charge of the battery (SOCbat) and the state of charge of the supercapacitors (SOCsc). The SOC of the SCs is defined linearly from the voltage while that of the battery results from the Coulomb counting method. They are defined as follows:

[0082] (10) with

[0083] - SOC sc designating the state of charge of the SC(s) 12

[0084] - SOCbat designating the state of charge of battery 11,

[0085] - SOCbat init designating the initial state of charge of battery 11,

[0086] - Ibat designating the current of battery 11,

[0087] - Vc designating the no-load voltage of the SCs, which corresponds to the voltage at all times across the terminals of the capacitor Csc (see figure 3),

[0088] - Vsc designating the voltage across the terminals of the SC 12 (see figure 3),

[0089] The charge states of battery 11 and SC 12 are defined between 0 and 1. We will take care to express Cbat in As (Ampere seconds). We then deduce:

[0090] Neglecting losses, the powers of the hybrid energy storage device I are expressed as follows: with =

[0091] - Pcharge designating the power required by the load

[0092] - Psc designating the power of the SC(s) 12, - Pbat designating the power of battery 11,

[0093] We then seek to define the power P sc of the SC 12 and the power Pbat of the battery 11 according to their respective voltages and currents:

[0094] For supercapacitors 12

[0095] For battery 11

[0096] (16) (17) with:

[0097] - Ibat designating the current of battery 11,

[0098] - Isc designating the current of the SC 12(s),

[0099] - Vbat designating the voltage of battery 11,

[0100] - Vsc designating the voltage of the SC 12(s),

[0101] - Rbat designating the series resistance of battery 11 (see figure 3),

[0102] - Rsc designating the series resistance of SC 12 (see figure 3),

[0103] - V c designating the voltage across the capacitor Csc of the SC model (see figure 3),

[0104] - Vocv designating the no-load voltage of the battery (see figure 3).

[0105] Using equations (9), (12), (13), (14) and (15), we obtain equation (18) [9] :

[0106] (18) Using equations (16), (17) and (11), we obtain equation (19) [9] :

[0107] The cost function J to minimize is as follows:

[0108] We will therefore seek to control the state of charge of the supercapacitors by minimizing the difference between the estimated SOCsc (i.e. the state of charge of the SCs estimated from the measurement and the model of the hybrid source) and the reference SOCscref (i.e. the reference state of charge of the SCs 12). We will also seek to penalize the battery power. Indeed, we want the battery to be used as little as possible during the operation of the hybrid source. The weights wi and W2 are defined in such a way as to emphasize one objective rather than another. Given the different orders of magnitude between the state of charge of the SC 12 (order of magnitude of 1) and the power of the battery 11 (order of magnitude between 1kW and 10kW), i.e. the SOC sc and Pbat, it is necessary to normalize the cost function using the weights wi and W2, so that each term has a significant action.We will choose to normalize the objective function J around 1 and only the weight W2 must be modified, so that:. with :

[0109] - P max load designating the maximum power required by the load, and

[0110] - W2b designating the weight to be adjusted.

[0111] The value of the weights of the cost function J can then be refined. By increasing wi, the variation of the voltage of the SC 12 is reduced around its reference voltage. The larger the value of W2b, the more the battery power is minimized. The system constraints are defined so that:

[0112] Pb,,.. ' P... s ■ (22) with :

[0113] - J denoting the cost function (or the objective function), and

[0114] - N p designating the prediction horizon, and

[0115] - wi and W2 the weights of the cost function.

[0116] - SOCscref designating the reference state of charge of the SC 12(s),

[0117] - (k + i|k) corresponds to the predicted value of the variable to which this index is attached

[0118] - and Pbmax, the minimum and maximum limits of battery power 11,

[0119] - SOCsc min and SOCsc max, the minimum and maximum limits of the SOC of SC 12,

[0120] - SOCsc min Ct SOCsc max, the minimum and maximum limits of the battery SOC 11.

[0121] In the context of control B2) of the hybrid energy storage device 1, Pbat is the control variable and P vcan be assimilated as a disturbance. The constraints of the SC SOC will be defined between 1 and 0.5, which corresponds according to equation (9) to the use of 75% of the SC energy. The SOC of the battery is defined in such a way as to have a depth of discharge DOD of 80% (DOD being the acronym in English for "Depth of Discharge"). The variation of SOCbat was set arbitrarily between 0.9 and 0.1. The acaods software was used to solve the MPC. The transition from the NMPC to the internal loop BI requires dividing the battery power by its voltage in order to obtain Ibat. The complete control diagram can be found in Figure 4.

[0122] Figure 5 shows that the algorithm of step B2 is separated into two parts including:

[0123] - a first part consisting of the internal loop BI to control the current of the super capacitor 12, and

[0124] - a second part consisting of the external loop BE made up of said predictive control NMPC2.

[0125] More specifically, these two loops (internal BI and external BE) are cascaded to control converter 13: the internal loop (inspired by the work of Nguyen [8] ) consists of a Proportional Integral corrector (or PI corrector) whose role is to control the input current of the converter 12, i.e. the current of the supercapacitors 12 (internal loop); the external loop (inspired by the work of Golchoubian [9] ) slower than the internal loop, has the role of managing and sharing energy between the two storage systems (battery and SC) and the load.

[0126] A current setpoint will thus be calculated by the external loop and sent to the input of the internal loop in order to control the converter 13 as illustrated in figure 5.

[0127] The method according to the invention therefore makes it possible to improve the power sharing between the battery 11 and the supercapacitor 12 compared to rule-based algorithms. It makes it possible to have better aging indicators and to better manage the constraints on the battery as well as the critical limits of the battery and the SCs (in particular in terms of overcharging and discharges).

[0128] REFERENCES

[0129] 1. RE Araujo, R. De Castro, C. Pinto, P. Melo, and D. Freitas, “Combined sizing and energy management in evs with batteries and supercapacitors” IEEE Transactions on Vehicular Technology, vol. 63, no. 7, pp. 3062-3076, 2014.

[0130] 2. L. Zhang, X. Hu, Z. Wang, F. Sun, J. Deng and DG Dorrell, “Multiobjective Optimal Sizing of Hybrid Energy Storage System for Electric Vehicles” in IEEE Transactions on Vehicular Technology, vol. 67, no. 2, pp. 1027-1035, Feb. 2018,

[0131] 3. J. M. Gonzalez-Gonzalez, S. Martin, P. Lopez, and J. A. Aguado, “Hybrid batteryultracapacitor storage system sizing for renewable energy network integration," IET Renewable Power Generation, vol. 14, pp. 2367{2375, oct 2020.

[0132] 4. A. Ostadi and M. Kazerani, ‘M comparative analysis of optimal sizing of battery-only, ultracapacitor -only, and battery-ultracapacitor hybrid energy storage systems for a city bus" IEEE Transactions on Vehicular Technology, vol. 64, pp. 4449{4460, oct 2015.

[0133] 5. V. Herrera, A. Milo, H. Gaztanaga, I. Etxeberria-otadui, and I. Villarreal, “ Adaptive energy management strategy and optimal sizing applied on a battery-supercapacitor based tramway," Applied Energy, vol. 169, pp. 831-845, 2016

[0134] 6. Rui Xiong, Hongwen He, Fengchun Sun “ Methodology for Optimal Sizing of Hybrid Power System Using particle Swarm Optimization and Dynamic Programming" Energy Procedia, vol. 75, pp. 1895-1900, 2015.

[0135] 7. S. Trieste, S. Hmam, J. C. Olivier, S. Bourguet, and L. Loron, “Techno-economic optimization of a supercapacitor-based energy storage unit chain'. Application on the first quick charge plug-in ferry" Applied Energy, vol. 153, pp. 3-14, sep 2015.

[0136] 8. H. Nguyen, R. German, J. P. F. Trovâo and A. Bouscayrol, "Real-Time Energy Management ofBatery / Siipercapacitor Electric Vehicles Based on an Adaptation of Pontryagin’s Minimum Principle" in IEEE Transactions on Vehicular Technology, vol. 68, no. 1, pp. 203-212, Jan.

[0137] 2019, doi: 10.1109 / TVT.2018.2881057

[0138] 9. P. Golchoubian, N. L. Azad, and K. Ponnambalam, “Stochastic Nonlinear Model Predictive Control of Battery-Supercapacitor Hybrid Energy Storage Systems in Electric Vehicles", vol. 9545, no. c, pp. 1 { 12, 2017.

Claims

CLAIMS 1. A method for managing energy of a hybrid energy storage device (1) in a stationary or mobile system, said hybrid energy storage device (1) comprising at least one main energy source (11), at least one auxiliary energy source (12), and at least one converter (13), said method comprising the following steps: - A) a first sizing step including Al) acquiring the following input parameters: power cycles of said system, and the technology of the main (11) and auxiliary (12) energy sources of said hybrid energy storage device, then A2) setting up an energy management strategy using a first predictive control MPC1 to obtain the following output data: the dimensioning data of said at least one main energy source (11) and said at least one auxiliary energy source (12) required and information relating to said at least one converter (13); - B) a second test step in simulation of the consistency of the output data obtained in step A) comprising the following sub-steps: Bl) modeling on the one hand of said at least one main energy source (11) and on the other hand of said at least one auxiliary energy source (12) as well as said at least one power converter (13) serving as an interface between said main and auxiliary energy sources (H, 12); B2) controlling said hybrid energy storage device (1) using an algorithm comprising an energy management loop consisting of a second predictive control NMPC2.

2. Method according to claim 1, in which the algorithm of step B2) is separated into two parts comprising: - a first part consisting of an internal loop (BI) to control the power of the auxiliary energy source (12), and - a second part consisting of an external loop (BE) made up of said predictive control NMPC2.

3. Method according to any one of claims 1 and 2, further comprising a third optional step C) of testing the algorithm of step B2 on a real system.

4. Method according to any one of claims 1 to 3, wherein each of the main (11) and auxiliary (12) energy sources is chosen from the group consisting of the following energy sources: batteries, fuel cells, supercapacitors and flywheels.

5. Method according to claim 4, wherein the main energy source (11) is a battery, and preferably a battery chosen from the group consisting of Li-ion batteries, sodium batteries, Li-air batteries and Li-solid batteries.

6. The method of claim 5, wherein the main power source (11) is a Li-ion battery and the auxiliary power source (12) is a supercapacitor.

7. Method according to any one of claims 1 to 6, in which successive iterations can be carried out between steps A) and B).

8. Method according to any one of claims 3 to 6, in which successive iterations can be carried out between steps B) and C).

9. Use of the method as defined according to any one of claims 1 to 8 in the field of electric mobility.

10. Use of the method as defined according to any one of claims 1 to 8 in the field of stationary applications, for the energy management of a hybrid energy storage device (1) in a stationary system.

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