JP6517092B2 - Battery charger, battery diagnostic device using the same, and battery regenerator - Google Patents

Description

  The present invention, for example, a battery charger capable of efficiently charging a battery such as a lead storage battery, a nickel hydrogen secondary battery, a lithium battery and the like, and diagnosing the deterioration state of the battery using this battery charger And a battery regenerator capable of recovering a deteriorated battery.

  In a battery-powered electric vehicle such as a forklift, a golf cart, or an in-building electric vehicle, when used for many years, the battery failure suddenly occurs and becomes unusable, which may cause problems in transportation work and the like.

  Also, in so-called electric vehicles (battery-type electric vehicles), which are strongly expected as a solution to environmental problems in recent years, there is a concern that a battery failure may suddenly occur as in the case of these electric vehicles.

  Especially in the case of an electric car, unlike an electric powered vehicle such as a forklift or a golf cart, it does not run only within a specific range, but also travels on public roads, etc., causing such a sudden battery failure. In some cases, it may lead to traffic accidents.

  In addition, mobile phones, PHS base stations, data centers, public facilities such as hospitals, etc. are equipped with an emergency battery in case of an abnormality in the power supply at the time of disaster or power failure, etc. In the case of emergency batteries, sudden failure will have a great social impact.

  With regard to batteries that cause a great deal of trouble when this kind of failure occurs, measures such as replacement with new batteries are carried out regularly, and many batteries have been discarded, and there are concerns about environmental impact. is there.

  For this reason, although it is required to extend the life of the battery, the prevention of the battery deterioration is not sufficiently performed. In daily maintenance of the battery, etc., it is significant to detect the deterioration of the battery at an early stage and to carry out the recovery procedure of the battery.

  In recent years, evaluation of charge acceptance performance has been adopted as an indication of battery performance. The deterioration of the battery causes the charge acceptance performance of the battery to deteriorate due to the following reasons, and the electrode becomes in a state of sleeping. For example, there may be cell inversion due to overdischarge of the battery, occurrence of sulfation due to deep discharge, or thermal runaway due to an increase in battery temperature when the battery is charged. In addition, it is also one of the causes that the varia occurs in the electrode and the abnormal substance adheres to the surface of the bolus.

When the charge acceptance performance of the battery is deteriorated due to such a cause, conventionally, the cause of the failure is identified, and the recovery and regeneration of the battery are attempted by taking a countermeasure according to the symptom.
The applicant has invented a battery regenerator and a battery charger as disclosed in Patent Documents 1 and 2 in order to perform such recovery and regeneration of the battery.

In the battery regenerator disclosed in Patent Document 1, the battery is regenerated by repeatedly charging and discharging the battery in which the number of times of discharge reaches a predetermined number of times set in advance.
By repeating charging and discharging in this manner, symptoms such as sulfation and balia can be eliminated, and a battery that has become difficult to use can be regenerated to be in a normally usable state.

  Further, in the battery charger disclosed in Patent Document 2, when the battery is charged, the battery is analyzed based on the charging signal, and the charging algorithm is automatically switched according to the state of the battery, the predetermined number of times or the predetermined The battery is repeatedly charged until the full charge completion condition is satisfied.

  By charging while switching the charging algorithm in this manner, charging can be performed efficiently, the load on the battery can be reduced, and the effect of extending the life of the battery can be obtained.

JP, 2009-284571, A International Publication No. 2012/053487

  As described above, even the battery charger and the battery regenerator disclosed in Patent Literatures 1 and 2 can perform charging for prolonging the life of the battery, regeneration of the deteriorated battery, and the like, but only a lot of electricity It only injects the battery, and the charging algorithm has not been optimized.

  Further, the charge acceptance performance of the battery is limited by the capacity of each battery, and even if the charge amount is increased beyond the capacity, the battery can not be effectively charged but becomes heat and eventually the electrode will be damaged.

  Furthermore, when the battery is deteriorated, the charge acceptance performance is also reduced, and only the charge amount less than the normal capacity can be accepted. Therefore, in the conventional charger, sufficient charging can not be performed, and even if the battery is fully charged, the battery may be exhausted earlier than expected.

  It should be noted that not only removal of the cause of the charging failure as described above but also elimination of abnormal ion concentration distribution in the electrolyte during charging, and further local void (dryout phenomenon in the electrolyte impregnated mat etc. The charge acceptance performance can also be improved by eliminating the problem (1) or improving the conductivity of the boundary layer between the active material and the grit.

  These can be achieved by charging in the critical charge state of the battery, but in the conventional charger, charge control in the critical charge state is not performed, and the battery will be damaged.

  In addition, since the capacity of an emergency battery is large and causes a transportation problem, it is difficult to play back the battery in the center back type. For this reason, on-site regeneration or battery activation is effective.

  In the present invention, by optimizing the charging algorithm, the supercritical charge state is formed, and the sleeping electrode is activated to improve the charge acceptance performance, and the charge power does not become heat, and the effective charge amount is increased. It is an object of the present invention to provide a battery charger capable of improving and efficiently charging in a short time, restoring cell balance, and extending battery life.

  Another object of the present invention is to provide a battery diagnostic device capable of diagnosing the state of a battery using such a battery charger, and a battery regenerator capable of performing regeneration of a deteriorated battery.

The present invention was invented to solve the problems in the prior art as described above, and the battery charger of the present invention is
Battery charging means for charging the connected battery;
Signal analysis means for analyzing the battery based on the charging signal sent from the battery charging means;
Control means for controlling charging by the battery charging means based on an analysis result in the signal analysis means;
A battery charger with
The control means
Strong constant current charging process for constant current charging with a current of 0.06 CA to 0.25 CA;
A weak constant current charging step of performing constant current charging with a current of 0.01 CA to 0.05 CA of the current in the strong constant current charging step;
In-loop strong constant current charging process in which constant current charging is performed by a current of 0.0.06 CA to 0.25 CA, and in-loop weak fixing in which constant current charging is performed by a current of 0.01 CA to 0.05 CA in strong constant current charging in loop A loop charging step of alternately repeating the current charging step for a predetermined number of loops;
Constant voltage charging process for constant voltage charging;
Are sequentially executed.

With such a battery charger,
The control means
Preferably, the loop charging process is configured to be performed in multiples.

Moreover,
The control means
In the strong constant current charging process and the weak constant current charging process, it is preferable that the process be ended when it is determined that the charge voltage of the battery exceeds the full charge voltage of the battery. .

Moreover,
The control means
In the in-loop strong constant current charging process and the in-loop weak constant current charging process, when it is determined that the charging voltage of the battery exceeds the supercritical charging voltage of the battery, the loop charging process is ended. It is preferable that it is comprised.

Also, the battery diagnostic device of the present invention is
A battery charger according to any of the above;
A battery discharger for discharging the battery;
Equipped with
The control means
Before the step of the strong constant current charging step, a discharging step of discharging the battery for a predetermined time by the battery discharger is performed;
The signal analysis means
While the strong constant current charging process, the weak constant current charging process, and the loop charging process are being performed, the charging voltage of each cell of the battery is measured;
The battery may be diagnosed based on a change in the charging voltage.

Also, the battery regenerator of the present invention is
A battery charger according to any of the above;
A battery discharger for discharging the battery;
Equipped with
The control means
The battery may be regenerated by repeatedly charging and discharging the battery using the battery charger and the battery discharger.

  According to the present invention, it is possible to perform charging at a supercritical charging voltage which can not be achieved by the conventional battery charger, and it is possible to maximize the charge acceptance performance and to activate the sleeping electrode.

  Furthermore, in order to reduce the load on the battery, charging near the supercritical charging voltage (in-loop strong constant current charging) and in-loop weak constant current charging are repeated. The battery can be regenerated in a short time, the electrodes can be activated, and the battery life can be extended.

  Further, by setting a plurality of charge termination conditions and abnormality detection conditions, fine charge control can be performed in the supercritical charge state, and charge acceptance performance can be effectively improved without damaging the battery. It can be charged.

  In addition, a battery diagnostic using such a battery charger is capable of detecting a significant difference that occurs in changes in charging voltage per cell when charging the battery, and at the same time as charging the battery, the battery balance of the battery. Diagnosis can be performed, and battery deterioration can be detected early.

  Further, in the battery regenerator using the battery charger of the present invention, by performing charge control in the supercritical charge state, it is possible to restore the cell balance of a delicate nickel hydrogen battery, lithium ion battery or the like.

FIG. 1 is a block diagram for explaining the configuration of an embodiment of the battery charger according to the present invention. FIG. 2 is a flow chart for explaining a charging algorithm of the battery charger 10. FIG. 3 is a sub-flowchart for explaining the loop charging algorithm of FIG. FIG. 4 is a graph showing temporal changes in charging voltage and charging current when charging is performed using the battery charger 10. FIG. 5 is a graph in which the range during constant voltage charging in the graph of FIG. 4 is enlarged. FIG. 6 is a graph comparing the charge-discharge characteristics of the battery when charged by the conventional battery charger and the charge-discharge characteristics of the battery when charged by the battery charger of this embodiment. FIG. 7 is a schematic configuration view for explaining the configuration in one embodiment of the battery diagnostic device of the present invention. FIG. 8 is a flowchart for explaining the flow of performing battery diagnosis by the battery diagnostic device. FIG. 9 is a graph showing changes in charging voltage of the battery used when performing battery diagnosis by the battery diagnostic device. FIG. 10 is a schematic configuration view for explaining a configuration in one embodiment of the battery regenerator according to the present invention.

Hereinafter, embodiments (examples) of the present invention will be described in more detail based on the drawings.
FIG. 1 is a block diagram for explaining the configuration of an embodiment of the battery charger according to the present invention.

  As shown in FIG. 1, the battery charger 10 is connected to the battery 50, and analyzes the battery based on a battery charging means 20 for charging the battery 50 and a charging signal sent from the battery charging means 20. A signal analysis means 30 and a control means 40 for controlling the charge by the battery charging means 20 based on the analysis result in the signal analysis means 30 are provided.

  As the charging signal sent from the battery charging means 20, the battery voltage (hereinafter referred to as "charging voltage") at the time of charging the battery 50, the current flowing to the battery (hereinafter referred to as "charging current"), etc. It may be used as a signal, or the charging voltage or the charging current may be transmitted as a digital signal through an AD conversion circuit (not shown).

  When the signal sent from the battery charging means 20 is a charging voltage or charging current, for example, it is interposed between the battery charging means 20 and the signal analysis means 30 via a shunt or a voltage divider. As the electrical signal flowing to the signal analysis means 30, only a necessary and sufficient amount can be taken out.

  Also, when the signal sent from the battery charging means 20 is a digital signal, for example, a digital transmitting / receiving device for transmitting / receiving the digital signal as it is, or transmitting / receiving as a signal with error code correction function. A digital transmission / reception device with an error code correction function can be used.

  The battery charging unit 20 includes a power supply unit for supplying electric power, and a transformer for transforming charge current and charge voltage. The battery charging unit 20 is not limited to the configuration of the present embodiment, and for example, a switching power supply using PWM (Pulse Width Modulation) control or the like can also be used.

  Further, as the signal analysis means 30, as a means capable of analyzing the battery based on the signal sent from the battery charging means 20, for example, a microcomputer, a custom IC, an FPGA (Field Programmable Gate Array), etc. It can be used. The signal analysis unit 30 may be a computer such as a personal computer or a server provided outside the battery charger 10.

  Further, as the control means 40, for example, a microcomputer or a custom as a means capable of controlling the battery charging means 20 based on the analysis result by the signal analysis means 30, and changing the charging current or the charging voltage to the battery 50. An IC, an FPGA (Field Programmable Gate Array), or the like may be used, or a computer such as a personal computer or a server provided outside the battery charger 10 may be used. The control means 40 can also be configured as an integral unit with the signal analysis means 30.

  In addition, the control means 40 may be incorporated in the battery charging means 20. That is, the control means 40 may be a single device, may be integral with the battery charging means 20, or may be integral with the signal analysis means 30.

  Further, the control means 40 is provided with data storage means 42 for storing, as data, charging signals such as charging voltage and charging current sent from the battery charging means 20 and elapsed time during charging.

  The data storage means 42 stores data such as charge signals obtained at the time of charging performed in the past and elapsed time during charging, etc. The condition can be diagnosed.

  In addition, the signal analysis means 30 can be provided with an abnormality warning means 32 for notifying of an abnormality when, for example, a charging abnormality occurs. As the abnormality warning means 32, for example, a means for notifying by sound such as a buzzer, a means for notifying by light such as a lamp, a means combining them, a display means not shown such as a liquid crystal display, etc. can be used.

  Further, when a computer or the like is used as the signal analysis means 30, for example, an alarm may be displayed on a display connected to the computer. Furthermore, an alarm can be displayed on a mobile terminal such as a smartphone, a tablet, or a laptop computer via the Internet or a LAN (Local Area Network).

In the battery charger 10 of this embodiment configured as described above, the battery 50 is charged as follows.
2 is a flowchart for explaining the charging algorithm of the battery charger 10, FIG. 3 is a subflowchart for explaining the algorithm of the loop charging of FIG. 2, and FIG. 4 is a charging using the battery charger 10. It is a graph which shows the time change of the charge voltage at the time of performing, and charge current.

  When charging of the battery 50 is started (S10), first, strong constant current charging is performed (S20). In strong constant current charging, constant current charging is performed with a current of 0.06 CA to 0.25 CA, preferably 0.10 CA to 0.20 CA, based on the nominal capacity of the battery 50.

  As shown in FIG. 4, by performing strong constant current charging on the battery 50, the charging voltage (battery voltage) gradually rises. During this time, the signal analysis means 30 sequentially monitors the charging voltage of the battery 50, and the control means 40 determines whether the charging voltage satisfies the charge end condition described later (S30).

  When the charge voltage satisfies the charge termination condition, charging is continued for a predetermined time (S40), and then charging is stopped for a predetermined first pause time (S50). When the battery 50 is charged, the ion concentration gradient becomes large in the vicinity of the electrode of the battery 50 due to the charging reaction, so that the first pause time can be appropriately set as the time for uniforming this.

Next, weak constant current charging is performed (S60). In weak constant current charging, constant current charging is performed with a current of about 0.01 CA to 0.05 CA.
As shown in FIG. 4, by performing weak constant current charging on the battery 50, the charging voltage (battery voltage), which has once dropped at the time of stopping charging, gradually rises. During this time, the signal analysis means 30 sequentially monitors the charging voltage of the battery 50, and determines whether the charging voltage satisfies the charging end condition described later of the battery 50 (S70).

  When the charge voltage satisfies the charge termination condition, charging is continued for a predetermined time (S80), and then charging is stopped for a predetermined second pause time (S90). The second pause time is preferably the same as the first pause time, but may be shorter or longer than the first pause time.

  Next, loop charging is performed (S100). The loop charging is performed by repeating strong constant current charging and weak constant current charging, with S105 to S140 shown in FIG. 3 as one charge cycle.

  First, charging conditions for loop charging are set (S105). Here, the charge condition includes the magnitude of the charge current in the in-loop strong constant current charge and the in-loop weak constant current charge described later, and the charge end condition described later.

  The charge termination condition can be appropriately selected from the conditions to be described later, and can be set by combining a plurality of charge termination conditions. Note that the charge end condition may be changed for each loop, may be changed each time the loop charge is performed a predetermined number of loop times, or may be changed when the charge end condition is abnormally ended during the loop charge. May be resumed.

  In the in-loop strong constant current charging in the loop charging, constant current charging is performed with a current of about 0.06 CA to 0.25 CA, as in the case of the strong constant current charging in S20 described above (S110).

  By performing the strong constant current charging and the weak constant current charging as in S20 to S80, the battery 50 is in a state where the charging is almost completed. Therefore, by performing in-loop strong constant current charging, the charging voltage (battery voltage) rises higher than the normal full charging voltage, and an overvoltage occurs.

  Generally, it is said that overcharging under such an overvoltage condition shortens the life of the battery and causes a failure, but in the present invention, the charging voltage is up to the supercritical charging voltage of the battery 50. I am trying to rise.

  The critical charge voltage refers to the charge voltage when the charge reaction of the battery electrode is kept in the radical state in the fully charged state of the battery. Here, the dry out phenomenon in which the ion state of the electrolyte becomes a complex complex state is eliminated. Specifically, for a lead battery with a full charge voltage of 2.5 V per cell, 2.7 V is the critical charge voltage. The supercritical charging voltage is 2.9 V which is about 8% higher than the critical charging voltage. Thus, for a 12 volt lead battery (6 cells), the supercritical voltage is 17.5 volts.

  In addition, in the case of a nickel hydrogen battery in which the full charge voltage per cell is 1.38 V, the critical charge voltage is 1.42 to 1.45 V, and the supercritical charge voltage is 1.46 to 1.49 V. Thus, for a 12 cell nickel hydrogen battery, the supercritical charging voltage is 17.5 to 17.9 V, for a 20 cell nickel hydrogen battery, a supercritical charging voltage is 29.2 to 29.6 V, nickel for 188 cells In the case of a hydrogen battery, the supercritical charging voltage is 274-280V.

  The full charge voltage of the battery, the critical charge voltage, and the supercritical charge voltage have temperature dependency, and these voltages become high when the battery temperature is low, while these voltages are high when the temperature is high. The critical charging voltage and the supercritical charging voltage described above are only examples because they become lower, and can be changed as appropriate depending on the type of battery and the use conditions.

That is, in the signal analysis means 30, the charging voltage of the battery 50 is sequentially monitored, and it is determined whether the charging voltage exceeds the supercritical charging voltage of the battery 50 (S115).
Then, when the charging voltage exceeds the supercritical charging voltage, the charging is stopped only for a predetermined third pause time (S120). The third pause time is preferably the same as the second pause time.

  In addition, it is preferable to comprise so that loop charge S100 may be complete | finished, when abnormality detection conditions which are mentioned later are satisfy | filled during in-loop strong constant current charge (S111).

  Next, in the in-loop weak constant current charging, constant current charging is performed using a current of about 0.01 CA to 0.05 CA in strong constant current charging (S130), as in the above-described weak constant current charging in S50. During this time, the signal analysis means 30 sequentially monitors the charging voltage of the battery 50, and determines whether the charging voltage satisfies the charging end condition of the battery 50 described later (S135).

  Then, if the charge voltage satisfies the charge termination condition, the charging is stopped for a predetermined fourth pause time (S140). The fourth pause time is preferably the same as the third pause time.

  In addition, it is preferable to configure so as to end the loop charge S100 when an abnormality detection condition to be described later is satisfied during in-loop weak constant current charging (S131).

  As described above, by combining the strong constant current charging and the weak constant current charging during the loop charging, in the case of the battery 50 in the early stage of deterioration, the activation of the electrode active material is recovered.

  As shown in FIG. 4, by performing loop charging, the charging voltage during weak constant current charging in the loop gradually increases as the charging cycle is repeated. Then, it is determined whether or not the charge cycle has been executed for a predetermined number of predetermined loop times (S145). If the predetermined number of loops has not been reached, the process returns to S110 in-loop strong constant current charging. The loop charging is continued, and when the loop number is reached, the loop charging is ended (S150).

  In addition, it is preferable to set the charge amount of the battery by loop charge to about 10 to 20% of the whole, and when charge time is used, it is preferable to set loop charge time to about 40 to 60% of total charge time.

In addition, it is desirable that the in-loop strong constant current charge and the in-loop weak constant current charge have a charge amount of 1: 1 to 1: 3.
The in-loop strong constant current charge plays a role of keeping the battery in the supercritical charge state, and the in-loop weak constant current charge plays a role of increasing the effective charge of the battery.

  Thus, charging is efficiently performed in a short time by performing loop charging that alternately performs in-loop strong constant current charging that raises the battery charging voltage to a supercritical charging voltage and weak constant current charging with a small load. While reducing the load on the battery.

  Alternatively, after loop charging is completed, charging may be stopped for a predetermined loop pause time, and charging conditions such as charging current may be changed to perform loop charging (S100) in the next step.

  That is, it is determined whether or not the number of times of loop charging has reached a predetermined number of steps (S155). If the number of steps has not been reached, loop charging of S100 is repeatedly performed. In this case, it is preferable to appropriately change the charge condition for each step, for example, to about half the charge amount of the previous loop charge or to 1.3 times the charge amount.

  As described above, by performing multiple loop charging with different charging conditions, it is possible to finely adjust the level of strength in loop charging, the level of the charging amount for each loop charging, etc., and regenerate the battery to accept the charge. The performance can be restored to effectively charge the battery.

  Although the change of the charge condition may be performed automatically as in the present embodiment, it is manually performed at the timing of the change of the charge condition when transitioning from the loop charge to the next loop charge, etc. The charging conditions may be changed.

Thereafter, constant voltage charging is performed to check the state of charge of the battery 50 (S160). In constant voltage charging, floating charging (float charging) is preferable.
During constant-voltage charging, as shown in FIG. 5, the charging current decreases with time, but the charging current increases in the overcharged state. Therefore, during constant voltage charging, the signal analysis means 30 sequentially monitors the charging current of the battery 50, and determines whether the increase (+ ΔA2) of the charging current exceeds a predetermined charging completion increase value (see FIG. S170).

  Then, when the increase of the charging current exceeds the charging completion increasing value, the charging of the battery 50 is ended (S180).

  According to the battery charger 10 of the present invention configured as described above, charging can be performed in the vicinity of the supercritical charging voltage, which can not be achieved by the conventional battery charger, and activation charging of the battery 50 can be performed.

  Furthermore, in order to reduce the load on the battery 50, charging in the vicinity of the supercritical charging voltage (in-loop strong constant current charging) and weak constant current charging are repeated. Eliminate symptoms such as sulfation and balia, and extend the battery life.

  In addition, as the charge termination condition, a plurality of monitoring parameters as described below are set, and when any one of them is satisfied, charging is efficiently finished in a short time by terminating the charging. The load on can be reduced.

(1) Normal full charge detection For example, charging is terminated when the battery 50 is fully charged by detecting the charge amount, or after full charge detection, charging is performed for a predetermined time Tc using a timer. Charging can be terminated at the same time.

(2) Detection of -ΔV2 If the maximum battery voltage at the n-th charging falls below the maximum battery voltage at the n-1st charging during loop charging, the value is detected as -ΔV2 When -.DELTA.V2 becomes larger than a predetermined set value, it is determined that the full charge condition is satisfied, and charging can be completed.

  As described above, when -.DELTA.V2 becomes large, it can be determined that the battery can not be charged any more, that is, it can be determined that the battery has reached the charging limit, so the battery charging is normally terminated. be able to.

  The set value of −ΔV 2 can be appropriately set according to the type of battery and rated voltage, but for example, in the case of a battery rated at 48 V, 0.1 V (as battery voltage) as the average value of all cell voltages 2 to 2.5 V). It should be noted that the detection of -.DELTA.V2 as described above can be performed in any of a lead battery, a nickel hydrogen battery, and a lithium ion battery.

(3) Detection of -ΔV3 If the maximum battery voltage at the nth charge (m <n) is lower than the maximum battery voltage at the mth charge during loop charge, the value is When the .DELTA.V3 becomes larger than a predetermined set value, it is determined that the full charge condition is satisfied, and charging can be completed.

  As described above, when -.DELTA.V3 becomes large, it can be determined that the battery can not be charged any more, that is, it can be determined that the battery has reached the charging limit, so the battery charging is normally ended. be able to.

  The set value of -ΔV3 can be appropriately set according to the type of battery and the rated voltage. For example, in the case of a battery rated at 48 V, the average value of all the cell voltages is 0.1 V (as the battery voltage 2 to 2.5 V). It should be noted that detection of -.DELTA.V3 as described above can be performed in any of a lead battery, a nickel hydrogen battery, and a lithium ion battery.

(4) Detection of -ΔAH1 If the charge amount during loop charge decreases compared to the charge amount during loop charge of the previous step, the difference is detected as -ΔAH1 and -ΔAH1 is greater than a predetermined tolerance value If it also becomes large, it is determined that the full charge condition is satisfied, and charging can be completed.

(5) Detection of ΔAH1 When the charge amount during loop charge increases compared to the charge amount during loop charge of the previous step, the difference is detected as ΔAH1 and ΔAH1 becomes larger than a predetermined allowable value In this case, it is determined that the full charge condition is satisfied, and charging can be completed.

  By setting such a full charge condition and setting the following abnormality detection condition, when an abnormality occurs during charging, charging can be terminated and the battery 50 can be prevented from being damaged. .

(1) Detection of -.DELTA.V If the battery voltage drops during charging, the value is detected as -.DELTA.V, and if -.DELTA.V becomes larger than a predetermined set value, it is detected as abnormal. , To stop charging.

  The set value of −ΔV can be appropriately set according to the type of battery and the rated voltage. For example, in the case of a battery rated at 48 V, the average value of all the cell voltages is 0.1 V (as the battery voltage 2 V to about 2.5 V). In addition, it is often common to a nickel hydrogen battery that-(DELTA) V is detected like this.

(2) Detection of + ΔV During constant voltage charging, if the battery voltage suddenly rises, the value is detected as + ΔV, and if this + ΔV becomes larger than a predetermined set value, it is detected as abnormal. To stop charging.

  The set value of + ΔV can be appropriately set according to the type of battery and rated voltage. For example, in the case of a battery rated at 48 V, the average value of all cell voltages is 0.12 V (3 V as a battery voltage) Degree). Note that detection of + ΔV in this manner is particularly frequent in lithium ion batteries.

(3) Detection of + ΔA During constant voltage charging, the value of the current flowing to the battery may increase rapidly. This amount of increase is detected as ΔA, and when this ΔA becomes larger than a predetermined set value, it is detected as abnormal and charging is stopped.

  The set value of + ΔA can be appropriately set according to the type of battery and the current value at the time of constant current charging, but for example, in the case of a battery with a rated capacity of 400 AH, about 5 to 10 A it can. Note that the detection of + ΔA in this manner is particularly frequent in a nickel hydrogen battery.

(4) Detection of Vu The lower limit voltage Vu of the battery 50 is set, and when the charging voltage of the battery 50 falls below the lower limit voltage Vu, it is detected as abnormal and the charging is stopped.

(5) Detection of Vh The upper limit voltage Vh of the battery 50 is set, and when the charging voltage of the battery 50 exceeds the upper limit voltage Vh, it is detected as abnormal and the charging is stopped.

(6) Detection of Tt The charging upper limit time Tt is set, and when the charging time of the battery 50 exceeds the charging upper limit time Tt, it is detected as abnormal and the charging is stopped.

(7) Detection of Tlc The loop charge upper limit time Tlc during loop charge is set, and if the loop charge time exceeds the loop charge upper limit time Tlc, it is detected as abnormal and the charge is discontinued. .

(8) Detection of Al If the charging current falls below the lower limit current Al during constant voltage charging, it is detected as abnormal and charging is stopped.

(9) Detection of Vo A predetermined overvoltage monitoring start voltage V ₀ is set, and the charging voltage does not rise to the full charge voltage Vc of the battery 50 even if a predetermined time has elapsed after reaching the overvoltage monitoring start voltage Vo. To be detected as abnormal and to stop charging.

  By setting a plurality of charge termination conditions and abnormality detection conditions in this manner, fine charge control can be performed in the supercritical charge state, and the charge acceptance performance can be improved without damaging the battery 50. Charging can be performed.

  In this embodiment, when the abnormality detection condition is satisfied, the loop charge S100 is ended, and when the number of loop charges does not reach the predetermined number of steps in S155, the loop charge S100 is performed again. However, if it is dangerous to continue charging, the charging itself may be stopped.

  Immediately after the start of charging, the charging voltage of the battery 50 is in a transient state, and the voltage change is not stable. Therefore, it is preferable to set a predetermined charge transition time Tn and not to determine the charge end condition and the abnormality detection condition until the charge transition time Tn elapses from the charge start.

  FIG. 6 is a graph comparing the charge acceptance characteristic of the battery 50 when charged by the conventional battery charger and the charge acceptance characteristic of the battery 50 when charged by the battery charger of the present embodiment. a) is a graph which shows the relationship between the charge amount at the time of charge, and a voltage, FIG.6 (b) is a graph which shows the relationship between the discharge amount at the time of discharge, and a voltage.

  In addition, in FIG. 6, V, VV, and VVV charged using the conventional charger, discharged the battery, and measured the charge-discharge characteristic. On the other hand, M was charged using the battery charger 10 of this embodiment, and the battery was discharged to measure charge-discharge characteristics.

Note that V is a weak current, VV is a medium current, and VV is a result when charged with a large current.
As shown in FIG. 6, charging with medium current can perform more effective charging than charging with high current, and furthermore, charging slowly with low current is more than charging with medium current. It is possible to charge effectively. That is, the charge acceptance performance is better if charging is performed slowly with slow current.

  On the other hand, when the battery charger 50 of the present embodiment is used, even if charging is performed by medium current at the time of initial strong constant current charging, charging is performed by weak current using a conventional battery charger. More power can be charged and more power can be output as compared to the case where That is, the charge acceptance performance is better when charging is performed using the battery charger 10 of the present embodiment than charging using a conventional battery charger and a slow current. This is an effect of slowly charging in the loop at low constant current charging in the supercritical charging state.

  In addition, in M which is a present Example, although loop charge which combined strong constant current charge and weak constant current charge is performed, for example, loop charge of only strong constant current charge (strong constant current charge and charge suspension) It is estimated that the charge acceptance amount is smaller than M according to the present embodiment in the repetition) and in the loop charging with only the weak constant current charge (the repetition of the weak constant current charge and the charge suspension). That is, loop charging combining strong constant current charging and weak constant current charging can most activate the battery.

  FIG. 7 is a schematic configuration diagram for explaining the configuration of an embodiment of the battery diagnostic device of the present invention, and FIG. 8 is a flowchart for explaining the flow of performing battery diagnosis by the battery diagnostic device.

The battery diagnostic device 60 includes a battery charger 10 and a battery discharger 62 for discharging the battery 50.
Although control means may be provided in the battery discharger 62 for controlling discharge of the battery 50 by the battery discharger 62, in the present embodiment, the control means 40 of the battery charger 10 controls the battery discharger 62. Are configured to

  As in this embodiment, in order to use as the battery diagnostic device 60, in the control means 40, the battery charge means 20, the signal analysis means 30, and the battery discharger 62 are controlled as follows. .

  When the battery diagnosis is started (S200), first, the battery discharger 62 discharges for a predetermined time (S210). Thereby, discharge is performed according to the depth of discharge which each cell of battery 50 has.

  In this state, measurement of the charge voltage of each cell of the battery 50 is started by the signal analysis means 30 (S220), and the battery charger 10 performs strong constant current charging and weak constant current charging of the battery 50 according to the algorithm described above. Charging and loop charging are performed (S220).

  The signal analysis means 30 measures the charging voltage until the charging of the battery 50 is completed. When charging of the battery 50 is completed, the signal analysis means 30 analyzes the change of the charging voltage for each cell (S240).

  As described above, as shown in FIG. 9, when charging the battery proceeds by analyzing the change in the charging voltage while charging the battery 50, the charging voltage at the time of weak constant current charging in the loop is significant. A difference is detected. 7, 12, 20 and 24 are cell numbers of the battery cells.

  The cell balance of the battery 50 can be grasped based on the significant difference generated in the change of the charging voltage for each cell, and the battery 50 can be diagnosed.

FIG. 10 is a schematic configuration view for explaining a configuration in one embodiment of the battery regenerator according to the present invention.
The battery regenerator 70 can be basically configured in the same manner as the battery diagnostic device 60 described above, so the same components are denoted by the same reference numerals and the detailed description thereof will be omitted.

  In the battery regenerator 70 configured as described above, the battery can be regenerated by repeatedly charging and discharging the battery 50 by the control means 40 as disclosed in Patent Document 1.

With such a battery regenerator 70, even if the battery can not be charged by the conventional charger, the battery can be regenerated so as to be chargeable.
A capacitor may be connected in parallel to the battery cell to perform passive balancing.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto.
In the above embodiment, the supercritical charging voltage of the lead battery and the nickel hydrogen battery was mentioned as an example, but in the battery charger, battery diagnostic device, and battery regenerator of the present invention, for example, lithium ion battery, nickel cadmium battery etc. Can also be used.

  Further, as disclosed in Patent Documents 1 and 2, an abnormality is detected, and when an excessive load is applied to the battery, the charging is instantaneously terminated to prevent the failure of the battery. Various modifications are possible without departing from the object of the invention.

DESCRIPTION OF SYMBOLS 10 battery charger 20 battery charge means 30 signal analysis means 32 abnormality alarm means 40 control means 42 data storage means 50 battery 60 battery diagnostic device 62 battery discharger 70 battery regenerator

Claims (7)

Battery charging means for charging the connected battery;
Signal analysis means for analyzing the battery based on the charging signal sent from the battery charging means;
Control means for controlling charging by the battery charging means based on an analysis result in the signal analysis means;
A battery charger with
The control means
Strong constant current charging process for constant current charging with a current of 0.06 CA to 0.25 CA;
A weak constant current charging step of performing constant current charging with a current of 0.01 CA to 0.05 CA of the current in the strong constant current charging step;
In-loop strong constant current charging process performing constant current charging with a current of 0.06 CA to 0.25 CA, and in-loop weak constant performing constant current charging with a current of 0.01 CA to 0.05 CA of in-loop strong constant current charging A loop charging step of alternately repeating the current charging step for a predetermined number of loops;
Constant voltage charging process for constant voltage charging;
A battery charger characterized in that it is configured to perform sequentially. The control means
The battery charger according to claim 1, wherein the battery charger is configured to perform the loop charging process in multiples. The control means
The pre-set charge termination condition and abnormality detection condition are stored,
In the strong constant current charging process, the weak constant current charging process, and the loop charging process, the process is terminated when the charge termination condition or the abnormality detection condition is satisfied. The battery charger according to claim 1 or 2. The control means
In the strong constant current charging process and the weak constant current charging process, when it is determined that the charge voltage of the battery exceeds the full charge voltage of the battery, the process is terminated. The battery charger according to claim 3. The control means
In the in-loop strong constant current charging process and the in-loop weak constant current charging process, when it is determined that the charging voltage of the battery exceeds the supercritical charging voltage of the battery, the loop charging process is ended. A battery charger according to claim 3 or 4, characterized in that it is configured. The battery charger according to any one of claims 1 to 5,
A battery discharger for discharging the battery;
Equipped with
The control means
Before the step of the strong constant current charging step, a discharging step of discharging the battery for a predetermined time by the battery discharger is performed;
The signal analysis means
While the strong constant current charging process, the weak constant current charging process, and the loop charging process are being performed, the charging voltage of each cell of the battery is measured;
A battery diagnostic device that diagnoses the battery based on a change in the charging voltage. The battery charger according to any one of claims 1 to 5,
A battery discharger for discharging the battery;
Equipped with
The control means
A battery regenerator characterized in that the battery is regenerated by repeating charging and discharging of the battery using the battery charger and the battery discharger.

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