Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
  • H02J7/50—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries acting upon multiple batteries simultaneously or sequentially
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
  • H02J7/50—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries acting upon multiple batteries simultaneously or sequentially
  • H02J7/52—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries acting upon multiple batteries simultaneously or sequentially for charge balancing, e.g. equalisation of charge between batteries
  • H02J7/56—Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
  • G01R31/378—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] specially adapted for the type of battery or accumulator
  • G01R31/379—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] specially adapted for the type of battery or accumulator for lead-acid batteries
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
  • G01R31/392—Determining battery ageing or deterioration, e.g. state of health
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
  • G01R31/396—Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Definitions

• the invention relates to a method for managing a battery of rechargeable batteries comprising a sequential charging cycle of the batteries of the park in order of priority and an analysis of the state of charge of the batteries.
• the batteries of a park are usually recharged simultaneously or successively so as to keep them permanently charged.
• Intelligent charge management of each battery requires to take into account in particular the state of charge (SOC or "state of charge” in English) of each battery.
• a battery has, with time, a decrease in its capacity. This decrease is a function of the conditions of use of the battery and its importance is generally difficult to evaluate without a capacity measurement.
• a battery is considered defective and must be replaced when its capacity becomes less than 80% of its nominal or initial capacity. Intelligent management of a battery of batteries therefore also requires taking into consideration the state of health (SOH) of each of the batteries.
• SOH state of health
• priority is given to the most charged battery, to quickly provide a fully charged battery.
• the charge level of the batteries is determined by a measurement of the voltage of the batteries at rest. After a sequential charging of all the batteries for predetermined times, the priority criteria are reviewed if necessary, in particular when a battery is added or removed from the charger or when the priority battery has completed its charging cycle. The end of the charging cycle is determined by the duration of the charge, the temperature and / or the voltage of the charged battery.
• US Pat. No. 5,057,762 also describes the determination of the state of charge of batteries intended to be charged by the same charger, to define a sequence of priority for the sequential charging of these batteries.
• the state of charge of a battery is determined by measuring the voltage at the terminals of this battery in charge during a given period (2 minutes for 2 batteries). During this period, the batteries are successively charged with a high current, called “fast charge current”, while the other batteries are charged with a low current, called “slow charge current”. At the end of this period, the state of charge of the batteries is compared and, as before, the priority is given to the most charged battery, to charge one of the batteries as quickly as possible.
• WO-A-00/75678 and US Pat. No. 6,255,801 describe methods for determining the capacity and / or age of a battery according to electrical parameters, peak voltage and plateau voltage. , representative of a whiplash effect occurring at the beginning of discharge of a battery when it is fully charged.
• US Pat. No. 6,489,743 describes a method of managing a power plant, more particularly a power plant comprising batteries connected to photovoltaic modules.
• a regulator controls the charge of the batteries so as to load them successively to the maximum, taking into account their state of charge, when the source of solar energy is available.
• the control of the state of charge of the batteries is based on the quantity of ampere hours injected into each of the batteries.
• WO-A-2006/003287 discloses a method for establishing a load priority criterion according to the state of health of the batteries.
• the diagnosis of the state of health of the batteries is determined from electrical parameters representative of a whiplash effect in discharge, the effect observed at the beginning of discharge of a fully charged battery. This process makes it possible to recharge more frequently the batteries considered in bad condition following this diagnosis, even to recommend its replacement.
• the object of the invention is to provide a method for managing a battery of rechargeable batteries that does not have the drawbacks of the known systems and, more particularly, a method making it possible to optimize the management of the battery bank.
• FIGS 1 to 4 illustrate, in the form of flow charts, a particular embodiment of a management method according to the invention.
• FIG. 5 represents, as a function of time, the variations of the voltage U at the terminals of a fully discharged battery during a partial charge.
• FIG. 6 represents, as a function of time, the variations of the voltage Ucell at the terminals of an element of a battery during a partial charge, respectively after a complete discharge (in solid line) and after an incomplete discharge (in dashed lines).
• FIG. 7 represents the evolution of the electric parameters of a whiplash effect under load, during partial charges carried out under conditions similar to 0.1 C 10 , following discharges interrupted respectively at voltage thresholds of 1 , 95 V (curve A1), 1.90 V (curve A2), 1.80 V (curve A3), and 1.70 V (curve A4).
• FIG. 8 represents the evolution of the electrical parameters of a whiplash effect under load, during partial charges performed under conditions similar to 0.1 C 10 , as a result of discharges interrupted at the same voltage threshold of 1 , 75 V and respectively performed at 0.2C current regimes 10 (curve A5), 0.1C 10 (curve A6) and 0.01 C 10 (curve A7).
• FIG. 9 represents the evolution of the electric parameters of a whiplash effect in charge in the case of a non-degraded discharged battery (in solid line) and in the case of the same discharged and degraded battery (in dotted lines) .
• the management method according to the invention can be implemented in a control device by any appropriate means, and more particularly at means of a microprocessor in which the different steps of the management method are programmed.
• step F1 For an N battery bank, B1 is assigned to the 1 st battery charging, B2 to the next, and so on up to BN Ia last battery, the N batteries of the park are then loaded sequentially in this order priority, from B1 to BN (step F2).
• the control device checks, in a known manner, during the sequential charging cycle, whether the batteries have reached a predetermined discharge level, that is to say if they reach a predetermined discharge end criterion. for example a predetermined low threshold of voltage.
• a predetermined discharge level for example a predetermined low threshold of voltage.
• a battery is completely discharged, it is preferably at least temporarily disconnected from the discharge system, that is to say it is no longer allowed to undergo discharge. On the other hand, it can possibly still undergo a complete charge if its load revolution intervenes later during the current sequential charging cycle.
• the corresponding information in particular the number K of fully discharged batteries and their identity, is then stored. If, at the end of the sequential charging cycle, several batteries are completely discharged, the control circuit goes to a step (F3) management of K fully discharged batteries before returning to a new sequential charging step.
• the control circuit At the end of a cycle of sequential charging of the batteries, the control circuit first checks (F4) whether at least one battery is totally discharged (K ⁇ O?) . If this is not the case (output No of F4), the control circuit loops back to step F2 and launches a new cycle of sequential charging of the batteries, without having modified the order of priority.
• the control circuit can, in a preferred embodiment, loop back to step F1, which can set a new arbitrary order of priority.
• the control circuit checks (F5) if more than one battery is completely discharged (K> 1?) . If this is not the case (F5 No output), it means that only one battery is completely discharged.
• the control circuit loops back to step F2 and initiates a new cycle of sequential charging of the batteries taking account of the new priority order, that is to say recharging first the fully discharged battery.
• control circuit goes to the step F3 for managing the K discharged batteries before returning to a new sequential charging step. This then takes into account a possible new order of priority established at the end of this process, described in more detail below, with reference to Figure 2.
• the management of the discharged K batteries starts, in a step F7, with a simultaneous partial charge of all the totally discharged batteries, preferably for a period of predetermined duration, for example for one hour. .
• electrical parameters representative of a charging boost effect are measured for each of the recharged batteries. These measures are then used by the control circuit to analyze, in a step F8, the state of charge and the state of health of these K batteries.
• step F7 The simultaneous charging of fully discharged batteries during step F7 makes it possible to ensure that these batteries are charged under similar conditions, for example as regards the current and / or the temperature, and thus to ensure the reliability of the diagnosis. established during the analysis of their state of charge and / or health during step F8.
• the charging conditions do not need to be controlled to ensure a reliable diagnosis of the state of the batteries.
• the state of charge of these K batteries is then used to update, in a step F9, the load priority order, which will be used during the next sequential charging cycle (F2).
• the analysis of the state of charge of the batteries comprises the comparison of the discharge depth of the different batteries recharged simultaneously. This depth of discharge is more particularly representative of the state of the matter of fully discharged batteries.
• the order of priority is then preferably modified (F9) to load, in the next sequential charging cycle, the most deeply discharged batteries.
• step F10 The analysis of the state of health of the batteries partially and simultaneously recharged during the step F7 makes it possible, among other things, to detect the defective batteries.
• This state of health can be used, in a step F10, to trigger maintenance actions and / or replacement of defective batteries.
• a maintenance action of step F10 may consist in adapting the charging strategy according to the state of health of each battery.
• the steps F9 and F10 are performed in parallel, they may possibly be carried out successively.
• FIG. 3 illustrates in greater detail, in flow chart form, a particular embodiment of step F2 of sequential charging of the batteries according to the order of priority in effect (from B1 to BN).
• This example is applicable in particular in installations in which the energy is not necessarily permanently available for charging the battery bank, for example in the case of a hybrid photovoltaic or photovoltaic installation with a diesel generator.
• the sequential load starts, in a step F11, by the initial setting to 1 of an index x, making it possible to take account of the order of priority in force.
• the control circuit checks the availability of charge energy. If this energy is available (Yes output of F12), the charge of the Bx battery starts (F13).
• the control circuit periodically checks (F14) whether the charge of the battery Bx is complete, that is, whether a predetermined end of charge criterion is reached. If this is not the case (output No of F14), it loops back to step F12, to check the availability of the charging energy.
• the control circuit proceeds, in a step F17, to a control of the batteries in discharge, so as to detect if some batteries are totally discharged. If none of the batteries are completely discharged (No output of F18), the control circuit loops back to step F12, to resume the current load when the charging energy becomes available again (output Yes of F12). On the other hand, if at least one of the batteries is discharged (Yes output of F18), the control circuit disconnects it from the discharge system, only allowing it to undergo a full charge if its turn occurs in the current sequential charging cycle. . The control circuit stores the number K of fully discharged batteries and their identities before going back to step F12.
• step F2 of sequential charging all the batteries of the park were loaded successively in the order of priority in force at the beginning of this sequential charging cycle, using the available charge energy in the battery. 'installation.
• the control circuit put the totally discharged batteries on standby and memorized their number K and their identity, to then allow the management of the discharged batteries (F3) and the possible modification of the order of priority for the charging cycle. next sequential.
• the control of the batteries may possibly be carried out, permanently or periodically, in parallel with the sequential charging of the batteries or systematically at the end of each sequential charging step, when the batteries are all being discharged.
• the electrical parameters measured during step F7 and used (F8) for the analysis of the state of charge and / or health of the K fully discharged batteries are representative parameters.
• a whiplash effect in charge As illustrated in FIG. 5, which represents the variations, as a function of time t, of the voltage U at the terminals of a battery completely discharged during a partial charge, a whiplash effect under load is observable at the beginning of the charge. a battery previously sufficiently discharged.
• Whiplash charging is characterized by a peak voltage across the battery in a first phase of charging a sufficiently discharged battery, before a voltage drop to a plateau during the next phase.
• FIG. 6 represents the variations, as a function of time, of the voltage Ucell at the terminals of an element of a battery, of the lead-acid type, during a partial charge, respectively after a complete discharge (in continuous line) and after an incomplete discharge (in dotted lines). It appears from this figure that the whiplash effect in charge only appears if and only if the battery is previously sufficiently discharged.
• FIG. 7 represents the evolution of the electrical parameters of a whiplash effect in charge for a lead-acid type battery element, during partial charges carried out under similar conditions, as a result of discharges interrupted respectively at thresholds. with a voltage of 1.95 V (curve A1), 1.90 V (curve A2), 1.80 V (curve A3), and 1.70 V (curve A4).
• curves illustrate the relationship between the parameters representative of a whiplash effect under load and the conditions of the previous discharge, more particularly as a function of the end of discharge voltage threshold, in other words of the depth of discharge reached.
• the more end of discharge voltage threshold is low, that is to say the greater the depth of discharge is important, and the magnitude of the effect of the whiplash under load (Upic and / or ⁇ U) is important.
• FIG. 8 represents the evolution of the electric parameters of a whiplash effect in charge for a battery element, of the lead-acid type, during partial charges carried out under similar conditions, as a result of discharges interrupted at the same 1 threshold voltage, 75 V and respectively performed at 0.2C current regimes 10 (curve A5), 0.1 C- I0 (curve A6), and 0,01C 10 (curve A7).
• curves illustrate the relationship between the parameters representative of a whiplash effect under load and the conditions of the previous discharge, more particularly as a function of the current regime of the previous discharge, in other words depending on the state of the active ingredient of discharged batteries or the depth of discharge reached.
• the lower the rate of the previous discharge ie the greater the use of the active ingredient and the depth of discharge, and the greater the amplitude of the whiplash effect under load. is important.
• FIG. 9 represents the evolution of the electric parameters of a whiplash effect in charge in the case of a non-degraded discharged battery (in solid line) and in the case of the same discharged and degraded battery (in dotted lines) .
• the end of discharge voltage threshold is reached after a small amount of electricity is discharged and whatever the regime of the discharge current used.
• the whiplash effect under load becomes in this case particularly weak, or is no longer observed at all.
• the control circuit in order to analyze the state of charge and health of the K batteries (F8), the control circuit first checks (step F20) for each of the K batteries recharged if a blow effect of Whisk in charge was observed at the beginning of charge. Then, for the batteries for which a boosting effect has been observed (output Yes of F20), the control circuit compares (F21) their depths of discharge. In practice, the comparison of the depths of discharge is carried out by a comparison of the amplitudes of the whiplash effects in charge, the parameters of which were measured during the step (F7) for the different partially charged batteries. As indicated above with reference to FIGS. 7 and 8, the greater the amplitude of the whiplash effect, the more deeply the battery is discharged. This later allows the control circuit, when updating the order of priority (F9, fig.2), to load the most deeply discharged batteries. The batteries are then loaded sequentially in order of priority which depends on the depth of discharge of the different batteries.
• the whiplash effect in charge has not been observed (output No of F20) for a number K1 of analyzed batteries (K1 ⁇ K).
• the control circuit checks, for these K1 batteries, whether the conditions necessary to observe a whiplash effect are met. If this is not the case (output No of F22), the analysis of the state of charge and health of the batteries concerned is not continued. On the other hand, if the observation conditions are met (exit Yes of F22), which is the case for K2 batteries (K2 ⁇ K1) in the example of Figure 4, the batteries concerned are declared defective (F23).
• the control circuit can trigger maintenance actions and / or replacement of these defective batteries (F10).
• the control circuit distinguishes defective batteries that can continue to be used after a maintenance action of those to be replaced.
• the control circuit checks, in a step F24, if a battery declared defective in the previous step (F23) has already been declared defective before. If this is not the case (output No of F24), the control circuit considers that a maintenance action or rehabilitation can be undertaken.
• Such a maintenance action may consist in resorting to a force load ("boost charge” in English), which generally results in an increase in the high voltage threshold, in a pulsed current load or in a notification to the controller.
• a force load (“boost charge” in English)
• boost charge in English
• user to perform itself a maintenance action of the battery, which can result for example by a check of the electrolyte level and / or additional electrical measurements.
• the management method described above thus makes it possible to ensure intelligent management of a battery bank or of a set of electrochemical cells, ensuring uniform use and aging of the various batteries of the park as well as an optimization of their performance. service life.
• This management method makes it possible to take account of the state of charge batteries, to preferentially charge the deepest discharged batteries, and to take into account the state of health of the batteries, to trigger maintenance actions of the most degraded batteries and / or recommend their replacement. It is thus possible to optimize the reliability and performance of the battery bank.
• the priority criteria are preferably based on a diagnosis of the state of charge of the. batteries, and more particularly on a diagnosis of the state of the active substance of the discharged batteries, which makes it possible to load the most deeply discharged battery according to this diagnosis.
• This management method differs from the existing processes in particular by the nature of the diagnosis of the state of the batteries, which is based on the electrical parameters of a whiplash effect in charge, in particular on the comparison of the amplitudes of the knock-on effects. charging whisk corresponding to different batteries.
• This method has the advantage of taking into account the impact of the conditions of the previous charging and discharging cycles in the diagnosis of state of charge established, to establish this diagnosis not at the end of charge for subsequent refills but at the very beginning of recharging. It is thus possible to take into consideration the entire electrical history of the batteries analyzed.
• the establishment of the diagnosis does not require a discharge and, therefore, loss of energy, and also makes it possible to establish at the same time a diagnosis of the state of health of the batteries analyzed.
• the management method described above and, in particular, the recharging in priority of the most discharged batteries ensure the most homogeneous use possible of each of the batteries of a battery bank. This also makes it possible to avoid any oversizing of the battery bank and thus to reduce the cost of constant performance.
• the term battery used in the above description encompasses both batteries and electrochemical cells.
• the management method described above applies to all types of batteries. It is particularly well suited to ⁇ managing a lead acid battery bank, whose use is common in applications where energy production is intermittent energy to adapt production to demand, by example in photovoltaic applications.
• all types of charging or discharging can be used, taking into account the type of battery and / or the type of application in which this battery is used.
• the voltage across the battery and / or the charging and discharging current are monitored and / or measured during charging and / or discharging.
• all end of charge and end of discharge criteria can be used, based for example on voltage thresholds or voltage and / or current time profiles.
• step F3 may, for example, concern the management of all N batteries in the park and not only the management of the subset constituted by the K batteries discharged. In this case, all the batteries undergo the step of partial charging and measurement of electrical parameters representative of a whiplash charging. It is therefore not essential to detect before, during the sequential charging cycle, the fully discharged batteries. Indeed, step F3 also allows, by analyzing the parameters representative of a boost in charge, to determine whether a battery is discharged or not (using the distinction illustrated in FIG. determine its depth of discharge.
• the analysis of the discharge depth of each of the batteries can, moreover, be used to select the strategies of charge to be used during a subsequent cycle of sequential charging of the batteries.
• load strategy can be used.
• Standard charging strategies typically comprise successive phases during which the load is controlled by current or voltage. These phases are generally interrupted on stopping criteria according to voltage thresholds or charge quantities.
• a new charging strategy based on the depth of discharge, determined on the basis of the electrical parameters representative of a boosted charging effect observed at the beginning of charging a battery, may, for example, consist, for this battery , to add an overload phase following a standard charging procedure, to apply a boost load or a pulsed current.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)
• Secondary Cells (AREA)

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• 2006
  • 2006-05-11 FR FR0604193A patent/FR2901070B1/fr active Active
• 2007
  • 2007-05-11 EP EP07731441A patent/EP2016434A2/de not_active Withdrawn
  • 2007-05-11 WO PCT/FR2007/000800 patent/WO2007132086A2/fr not_active Ceased
  • 2007-05-11 CN CN2007800171094A patent/CN101443672B/zh not_active Expired - Fee Related
  • 2007-05-11 JP JP2009508427A patent/JP5350223B2/ja not_active Expired - Fee Related
  • 2007-05-11 US US12/226,543 patent/US8106632B2/en not_active Expired - Fee Related

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