Search

EP-4571335-B1 - METHOD FOR DETERMINING A REMAINING LIFETIME OF AN ENERGY STORAGE UNIT; ENERGY STORAGE MANAGEMENT DEVICE; AND SYSTEM

EP4571335B1EP 4571335 B1EP4571335 B1EP 4571335B1EP-4571335-B1

Inventors

  • SCHEMEL, BERTRAM
  • Türke, Florian

Dates

Publication Date
20260506
Application Date
20231213

Claims (15)

  1. A computer-implemented method (1000) for determining a remaining lifetime of an energy storage unit, the method comprising: acquiring (S1100) a temperature of the energy storage unit, an electrical current supplied from or to the energy storage unit and a terminal voltage of the energy storage unit; estimating (S1200) a state of charge, SoC, and a present value of an energy storage parameter of the energy storage unit based on the temperature, the electrical current and the terminal voltage; deriving (S1300) an aging model of the energy storage unit based on the SoC and the temperature, wherein the aging model is indicative of a predicted time evolution of the energy storage parameter of the energy storage unit; and determining (S1400) the remaining lifetime based on the derived aging model, the present value of the energy storage parameter and an initial value of the energy storage parameter; wherein the method (1000) further comprises at least one of: adjusting an electrical current supplied to the energy storage unit based on the remaining lifetime such that the SoC of the energy storage unit is within a target SoC range associated with a desired remaining lifetime; adjusting an electrical current supplied to the energy storage unit based on the remaining lifetime such that the temperature of the energy storage unit is within a target temperature range associated with a desired remaining lifetime; and controlling a temperature regulation device to heat or cool the energy storage unit based on the remaining lifetime such that the temperature of the energy storage unit is within a target temperature range associated with a desired remaining lifetime.
  2. The method (1000) according to claim 1, wherein acquiring the temperature, electrical current and terminal voltage, and estimating the SoC are performed for multiple points in time, and the aging model is derived based on the SoC and the temperature at one or more of the multiple points in time.
  3. The method (1000) according to any one of claims 1 or 2, wherein the aging model is derived based on the SoC and the temperature at a present point in time of the multiple points in time.
  4. The method (1000) according to any one of claims 1 or 2, wherein the aging model is derived based on an average SoC and an average temperature over two or more of the multiple points in time.
  5. The method (1000) according to any one of claims 1 to 4, wherein the aging model is based on an aging factor having a functional dependency on the SoC and the temperature of the energy storage unit.
  6. The method (1000) according to claim 5, wherein parameters in the functional dependency are determined by a regression based on a plurality of measurement points.
  7. The method (1000) according to claim 6, wherein each of the plurality of measurement points comprises a reference aging parameter associated with a given combination of SoC and temperature, wherein the reference aging parameter is derived based on a measured time evolution of the energy storage parameter of a corresponding reference energy storage unit.
  8. The method (1000) according to any one of claims 1 to 7, wherein the energy storage unit is a supercapacitor.
  9. The method (1000) according to any one of claims 1 to 7, wherein the energy storage unit is a battery.
  10. The method (1000) according to any one of claims 1 to 9, further comprising at least one of: outputting, on a graphical user interface, the remaining lifetime of the energy storage unit; scheduling replacement of the energy storage unit based on the remaining lifetime.
  11. An energy storage management device configured to perform the method (1000) according to any one of claims 1 to 10.
  12. A system comprising: an energy storage unit; and an energy storage management device according to claim 11.
  13. The system according to claim 12, further comprising: a system controller configured to transmit, to the energy storage management device, a desired remaining lifetime; and wherein the energy storage management device is configured to transmit, to the system controller, at least one of a target SoC range and a target temperature range required to reach the desired remaining lifetime.
  14. The system according to claim 13, further comprising: a power converter configured to supply electrical current from or to the energy storage unit; and wherein the system controller is configured to control the power converter to adjust an electrical current supplied from or to the energy storage unit based on the remaining lifetime such that the SoC is within the target SoC range associated with a desired remaining lifetime.
  15. The system according to any one of claims 13 or 14, further comprising: a temperature regulation device configured to heat and/or cool the energy storage unit; and wherein the system controller is configured to control the temperature regulation device to heat or cool the energy storage unit based on the remaining lifetime such that the temperature of the energy storage unit is within the target temperature range associated with a desired remaining lifetime.

Description

TECHNICAL FIELD The present disclosure relates to a method for determining a remaining lifetime of an energy storage unit, and to a corresponding energy storage management device and system. BACKGROUND An energy storage unit is an electronic piece of equipment that stores energy produced at one time for use at a later time. As an example, energy can be stored in various forms such as a chemical and/or an electrical potential. In this manner, the energy storage unit may help in accommodate a discrepancy between a demand for the energy and a production of the energy. As an example, energy storage units play an increasingly crucial role in modern energy grid systems by compensating an offset between peaks in production by renewable energy sources, such as wind and solar, and periods of high demand. Further examples in which energy storage units find application includes mobile devices such as laptops and smartphones, electric vehicles such as electric cars and drones, IoT (internet of things) devices such as sensors and smart home devices, medical devices such as pacemakers and hearing aids, and the like. Examples for an energy storage unit include a battery, a capacitor, and the like. Capacitors are used in various applications requiring many rapid charge and discharge cycles. As an example, capacitors may be used in automobiles, buses, trucks, trains, ships, industrial robots, cranes, elevators, and the like, where they are used for regenerative braking, short-term energy storage, or burst-mode power delivery. As another example, capacitors may be mounted on printed circuit boards where they may be used to absorb spikes in power delivered to an electronic component, thereby creating a constant steady stream of electricity required to power the electronic component. The properties of capacitors allow them to accept and deliver electric charge much faster compared to batteries, and to tolerate many more charge and discharge cycles compared to rechargeable batteries. Over time, as the energy storage unit ages, its ability to store energy may degrade. Typically, a degree of this degradation is indicated by a state of health, SoH, of the energy storage unit. The SoH describes a present ability to store energy as a percentage value with respect to a rated ability of the energy storage unit (e.g. as provided by a manufacturer). That means that the SoH has an initial value of 100% at the beginning of the lifetime of the energy storage unit (i.e. at the time of manufacture), and a final value of practically 0% at the end of the lifetime. Variability in manufacturing may cause the initial value to deviate from 100% to a certain extent (e.g. usually at the order to 5% or less). Typically, the end of the lifetime may be identified with a different value of the SoH greater than 0%. As an example, the end of the lifetime may be identified with a SoH value of 80% or even higher for performance-critical applications. A common technique to estimate the SoH of an energy storage unit is the so-called Miner rule in which stress and/or fatigue damages caused during charge-discharge cycles of the energy storage unit are linearly accumulated. US 2023/278463 A1 discloses that the health of a battery within an electric or hybrid electric vehicle may be estimated by receiving battery condition signals from a battery monitoring system within the vehicle. The received battery condition signals are used to estimate an SOH (state of health) of the battery and an SOC (state of charge) of the battery. The estimated SOH and the estimated SOC are used in combination with a degradation model to estimate one or more of a capacity loss-related parameter and a internal resistance-related parameter, which are then used to estimate a RUL (remaining useful life) value and/or a CBW (cumulative battery wear cost) value. MESBAHI TEDJANI ET AL: "Advanced Model of Hybrid Energy Storage System Integrating Lithium-Ion Battery and Supercapacitor for Electric Vehicle Applications", IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, IEEE SERVICE CENTER, PISCATAWAY, NJ, USA, vol. 68, no. 5, 15 April 2020, pages 3962-3972, XP011836567 deals with the advanced electrothermal modeling of a hybrid energy storage system integrating lithium-ion batteries and supercapacitors. The objective is to allow the aging aspects of the components of this system to be taken into account. The development of a model including the electrothermal behaviors makes it possible to evaluate the progressive degradation of the performance of the hybrid energy storage system. SUMMARY However, the SoH is only able to indicate a remaining lifetime of the energy storage unit in relative terms. The remaining lifetime refers to an amount of time until the end of the lifetime of the energy storage unit. In other words, knowing the SoH may not be sufficient to predict, in absolute terms, at which point in time (e.g. a calendar date) the end of the lifetime will be reached. Furthermore, even if a refere