JP2017011978A - Battery charger and battery diagnostic device using the same and battery regenerator - Google Patents

Abstract

By optimizing the charging algorithm, the load on the battery is small, the charging can be performed efficiently in a short time, and more charging can be performed compared to a conventional charger. Provided is a battery charger capable of extending the life of the battery. A strong constant current charging step for performing constant current charging with a current of 0.06 CA to 0.25 CA, and a constant current charging with a current of 0.01 CA to 0.05 of the current in the strong constant current charging step. A constant current charging step, a constant current charging step in the loop in which constant current charging is performed with a current of 0.06 CA to 0.25 CA, and a constant current of 0.01 CA to 0.05 CA in the strong constant current charging in the loop. A loop charging process in which a weak constant current charging process in a loop for performing charging is alternately repeated by a predetermined number of loops and a constant voltage charging process for performing constant voltage charging are sequentially executed. [Selection] Figure 2

Description

  The present invention provides, for example, a battery charger that can efficiently charge a battery such as a lead storage battery, a nickel hydride secondary battery, or a lithium battery, and a diagnosis of a deterioration state of the battery using the battery charger. The present invention relates to a battery diagnosis device capable of recovering and a battery regenerator capable of recovering a deteriorated battery.

  In an electric vehicle using a battery as a power source, such as a forklift, a golf cart, and a premises electric vehicle, if it is used for many years, the battery suddenly breaks down and becomes unusable, which may cause problems in transportation work.

  In addition, so-called electric vehicles (battery-type electric vehicles), which are strongly expected as mitigation measures for environmental problems in recent years, have a concern that a battery failure may suddenly occur as in these electric vehicles.

  In particular, in the case of an electric vehicle, unlike electric vehicles such as forklifts and golf carts, it does not travel only within a specific range, but also travels on public roads. 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 emergency batteries in the event of a power failure such as a disaster or power outage. Even for an emergency battery, if a failure occurs suddenly, it will have a great social impact.

  For such batteries that cause a lot of trouble when a failure occurs, measures such as periodically replacing them with new ones are taken, many batteries are discarded, and there are concerns about environmental impact. is there.

  For this reason, although the life extension of the battery is required, the battery deterioration prevention has not been sufficiently performed. In daily maintenance of a battery, it is meaningful to detect battery deterioration at an early stage and perform a battery recovery procedure.

  In recent years, evaluation based on charge acceptance performance has been adopted as an indicator of battery performance. The deterioration of the battery causes the battery charge acceptance performance to deteriorate due to the following causes, and the electrodes are in a sleeping state. For example, cell reversal due to overdischarge of the battery, generation of sulfation due to deep discharge, or heat escape due to increase in battery temperature when the battery is charged may occur. Another cause is the occurrence of burria on the electrodes and the adhesion of abnormal substances to the bolus surface.

When the charge acceptance performance of the battery is lowered due to such a cause, conventionally, after identifying the cause of the failure and taking a countermeasure according to the symptom, the battery can be recovered and regenerated.
The present inventor has invented a battery regenerator and a battery charger as disclosed in Patent Documents 1 and 2 in order to recover and regenerate such a battery.

In the battery regenerator disclosed in Patent Document 1, the battery is regenerated by repeatedly charging and discharging the battery when the number of discharges reaches a predetermined number set in advance.
By repeatedly charging and discharging in this manner, symptoms such as sulfation and vaglia can be resolved, and a battery that has become difficult to use can be regenerated and brought into 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, while the predetermined number of times or the predetermined number The battery is repeatedly charged until the full charge completion condition is satisfied.

  By performing charging while switching the charging algorithm in this way, it is possible to efficiently charge, reduce the load on the battery, and obtain the effect of extending the life of the battery.

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

  As described above, the battery charger and the battery regenerator disclosed in Patent Documents 1 and 2 were able to perform charging to extend the life of the battery or regenerate a deteriorated battery. Only the battery was injected, and the charging algorithm was not optimized.

  In addition, 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, it is not effectively charged but becomes heat, and eventually the electrode is damaged.

  Furthermore, when the battery deteriorates, the charge acceptance performance also declines, and only a charge amount less than the normal capacity can be accepted. For this reason, in the conventional charger, sufficient charge cannot be performed, and even if the battery is fully charged, the battery may run out earlier than expected.

  In addition to eliminating the causes of charging obstacles as described above, the distribution of abnormal ion concentration in the electrolyte during charging is eliminated, and local voids (dry-out phenomenon) in the electrolyte-impregnated mat are also eliminated. ) Or by improving the conductivity of the boundary layer between the active material and the grit surface, the charge acceptance performance can be improved.

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

  In addition, an emergency battery or the like has a large capacity and causes a transportation problem, so that it is difficult to regenerate the battery in the center back type. For this reason, on-site reproduction or battery activation is effective.

  In the present invention, by optimizing the charging algorithm, a supercritical charging state is formed and the sleeping electrode is activated to improve the charge acceptance performance, and the effective charge amount is increased without the charging power becoming heat. It is an object of the present invention to provide a battery charger that can improve and efficiently charge in a short time, restore cell balance, and extend battery life.

  Another object of the present invention is to provide a battery diagnostic device capable of diagnosing the state of the battery using such a battery charger and a battery regenerator capable of regenerating 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;
Based on the charging signal sent from the battery charging means, signal analysis means for analyzing the battery,
Control means for controlling charging by the battery charging means based on the analysis result in the signal analyzing means;
A battery charger comprising:
The control means includes
A strong constant current charging step of performing 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 step in which constant current charging is performed with a current of 0.006 CA to 0.25 CA, and in-loop weak constant charging in which constant current charging is performed with a current of 0.01 CA to 0.05 CA of in-loop strong constant current charging A loop charging step that alternately repeats the current charging step by a predetermined number of loops;
A constant voltage charging process for performing constant voltage charging;
Are sequentially executed.

With such a battery charger,
The control means is
It is preferable that the loop charging step is configured to be performed in a multiple manner.

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

Moreover,
The control means includes
In the in-loop strong constant current charging step and the in-loop weak constant current charging step, when it is determined that the charging voltage of the battery exceeds the supercritical charging voltage of the battery, the loop charging step is terminated. It is preferable to be configured.

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;
With
The control means includes
Before the strong constant current charging step, performing a discharging step of discharging the battery for a predetermined time by the battery discharger,
The signal analysis means includes
While the strong constant current charging step, the weak constant current charging step, and the loop charging step are being performed, the charging voltage for each cell of the battery is measured,
The battery is diagnosed based on a change in the charging voltage.

The battery regenerator of the present invention is
A battery charger according to any of the above,
A battery discharger for discharging the battery;
With
The control means includes
The battery is 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 that cannot be achieved by a conventional battery charger, 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 (strong constant current charging in the loop) and weak constant current charging in the loop are repeated, so the battery will not break down, rather The battery can be regenerated in a short time, the electrode can be activated, and the battery life can be extended.

  In addition, by setting multiple charge termination conditions and abnormality detection conditions, it is possible to perform fine charge control in a supercritical charge state, effectively improving charge acceptance performance without damaging the battery. Charging can be performed.

  In addition, a battery diagnostic device using such a battery charger can detect a significant difference that occurs in a change in the charging voltage for each cell when the battery is charged. Diagnosis can be performed and battery deterioration can be detected at an early stage.

  Moreover, in the battery regenerator using the battery charger of the present invention, the cell balance of a delicate nickel metal hydride battery or lithium ion battery can be recovered by performing charge control in a supercritical charge state.

FIG. 1 is a block diagram for explaining the configuration of an embodiment of a battery charger according to the present invention. FIG. 2 is a flowchart 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 changes over time in the 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 with a conventional battery charger and the charge-discharge characteristics of the battery when charged with the battery charger of the present embodiment. FIG. 7 is a schematic configuration diagram for explaining a configuration in an 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 a change in the charging voltage of the battery used when the battery diagnosis is performed by the battery diagnosis device. FIG. 10 is a schematic configuration diagram for explaining a configuration in an embodiment of the battery regenerator of the present invention.

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

  As shown in FIG. 1, the battery charger 10 is connected to the battery 50, and the battery charging unit 20 that charges the battery 50, and analyzes the battery based on the charging signal sent from the battery charging unit 20. A signal analysis unit 30 and a control unit 40 that controls charging by the battery charging unit 20 based on the analysis result of the signal analysis unit 30 are provided.

  As a charging signal sent from the battery charging means 20, a battery voltage (hereinafter referred to as “charging voltage”) at the time of charging the battery 50, a current flowing through the battery (hereinafter referred to as “charging current”), and the like are used as they are. The charging voltage or charging current may be transmitted as a digital signal via an AD conversion circuit (not shown).

  When the signal sent from the battery charging means 20 is a charging voltage, a charging current, or the like, for example, between the battery charging means 20 and the signal analysis means 30 via a shunt or a voltage divider. A necessary and sufficient amount of electrical signals flowing through the signal analyzing means 30 can be extracted.

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

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

  Further, as the signal analyzing means 30, as 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. Can be used. Note that the signal analysis means 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, as means for controlling the battery charging means 20 based on the analysis result by the signal analysis means 30 and changing the charging current or charging voltage to the battery 50, for example, a microcomputer or a custom 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 be configured as an apparatus integrated with the signal analysis means 30.

  Further, the control means 40 may be incorporated in the battery charging means 20. That is, the control unit 40 may be a single device, or may be integrated with the battery charging unit 20 or may be integrated with the signal analysis unit 30.

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

  The data storage means 42 stores data such as a charging signal obtained at the time of charging performed in the past and an elapsed time during charging. Based on these data, the signal analyzing means 30 stores the data of the battery 50. The condition can be diagnosed.

  Further, the signal analysis means 30 can be provided with an abnormality alarm means 32 for notifying abnormality when a charging abnormality occurs. As the abnormality alarm means 32, for example, means for notifying by sound such as a buzzer, means for notifying by light such as a lamp, a means combining them, a display means (not shown) such as a liquid crystal display, or the like 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 or the like 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 the present 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 sub-flowchart for explaining the loop charging algorithm of FIG. 2, and FIG. It is a graph which shows the time change of the charging voltage and charging current at the time of performing.

  When charging of the battery 50 is started (S10), first, strong constant current charging is performed (S20). In the 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, the charging voltage (battery voltage) is gradually increased by charging the battery 50 with a strong constant current. During this time, the signal analyzing means 30 sequentially monitors the charging voltage of the battery 50, and the control means 40 determines whether or not the charging voltage satisfies a charging termination condition described later (S30).

  If the charging voltage satisfies the charging termination condition, the charging is continued for a predetermined time (S40), and then the charging is stopped for a predetermined first pause time (S50). Note that, when the battery 50 is charged, the ion concentration gradient increases in the vicinity of the electrode of the battery 50 due to the charging reaction, and therefore the first pause time can be appropriately set as the time for equalizing the ion concentration gradient.

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) once lowered when the charging is stopped gradually increases. During this time, the signal analyzing means 30 sequentially monitors the charging voltage of the battery 50, and determines whether or not the charging voltage satisfies a charging termination condition described later of the battery 50 (S70).

  If the charging voltage satisfies the charging termination condition, the charging is continued for a predetermined time (S80), and then the charging is stopped for a predetermined second rest 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). In the loop charging, S105 to S140 shown in FIG. 3 are performed as one charging cycle, and the strong constant current charging and the weak constant current charging are repeated.

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

  The charge termination condition can be appropriately selected from the conditions described later, and a plurality of charge termination conditions can be set in combination. The charging end condition may be changed for each loop, or is changed every time the loop charging is performed for a predetermined number of loops, or the charging end condition is changed when the loop ends abnormally during the loop charging. May be resumed.

  In the in-loop strong constant current charge in the loop charge, the constant current charge is performed with a current of about 0.06 CA to 0.25 CA, similarly to the strong constant current charge 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 almost fully charged. For this reason, by performing strong constant current charging in the loop, the charging voltage (battery voltage) rises higher than the normal full charging voltage, and an overvoltage occurs.

  In general, it is said that overcharge in a state where such an overvoltage occurs shortens the life of the battery and causes failure, but in the present invention, the charge voltage reaches the supercritical charge voltage of the battery 50. I try to rise.

  The critical charging voltage refers to a charging voltage when the charging reaction of the battery electrode is maintained in a radical state when the battery is fully charged. Here, the electrolyte is in a state of eliminating the dry-out phenomenon in which the ionic state of the electrolyte becomes a complex complex state. Specifically, for a lead battery having a full charge voltage of 2.5 V per cell, 2.7 V is the critical charge voltage. The supercritical charging voltage is set to 2.9 V, which is about 8% higher than the critical charging voltage. Therefore, in the case of a 12V lead battery (6 cells), the supercritical voltage is 17.5V.

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

  Note that the full charge voltage, critical charge voltage, and supercritical charge voltage of the battery have temperature dependence, and these voltages increase when the battery temperature is low, while these voltages increase when the temperature is high. Therefore, the above-described critical charging voltage and supercritical charging voltage are merely examples, and can be appropriately changed depending on the type of battery, use conditions, and the like.

That is, the signal analysis means 30 sequentially monitors the charging voltage of the battery 50, and determines whether or not the charging voltage exceeds the supercritical charging voltage of the battery 50 (S115).
When the charging voltage exceeds the supercritical charging voltage, the charging is stopped 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 that the loop charging S100 is terminated when an abnormality detection condition described later is satisfied during the strong constant current charging in the loop (S111).

  Next, in the weak constant current charging in the loop, the constant current charging is performed with a current of about 0.01 CA to 0.05 CA of the strong constant current charging, similarly to the weak constant current charging in S50 described above (S130). During this time, the signal analyzing means 30 sequentially monitors the charging voltage of the battery 50, and determines whether or not the charging voltage satisfies a charging termination condition described later (S135).

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

  It should be noted that, when an abnormality detection condition described later is satisfied during the weak constant current charging in the loop (S131), the loop charging S100 is preferably terminated.

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

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

  Note that the charge amount of the battery by loop charging is preferably about 10 to 20% of the whole, and in terms of charging time, the loop charging time is preferably about 40 to 60% of the total charging time.

Further, it is desirable that the in-loop strong constant current charging and the in-loop weak constant current charging be in a charge amount of 1: 1 to 1: 3.
The strong constant current charge in the loop plays a role of maintaining the battery in a supercritical charge state, and the weak constant current charge in the loop plays a role of increasing the effective charge amount of the battery.

  In this way, charging is efficiently performed in a short time by performing loop charging that alternately performs strong constant current charging in the loop that raises the charging voltage of the battery to the supercritical charging voltage and weak constant current charging with a small load. In addition, the load on the battery can be reduced.

  Note that after the loop charging is finished, the charging is stopped for a predetermined loop pause time, and then the charging conditions such as the charging current are changed, and the loop charging (S100) of the next step can be performed.

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

  In this way, by performing multiple loop charging with different charging conditions, the level of strength in loop charging and the level of charge amount for each loop charging can be finely adjusted, and the battery is regenerated and accepted. The performance can be restored and the battery can be effectively charged.

  The charging condition may be changed automatically as in the present embodiment, but manually at a timing such as when the charging condition is changed when shifting from loop charging to the next loop charging. 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 when an overcharged state occurs. Therefore, during constant voltage charging, the signal analysis means 30 sequentially monitors the charging current of the battery 50 and determines whether or not the increase in charging current (+ ΔA2) exceeds a predetermined charging completion increase value ( S170).

  When the increase in the charging current exceeds the charging completion increase value, the charging of the battery 50 is terminated (S180).

  According to the battery charger 10 of the present invention configured as described above, it is possible to perform charging near the supercritical charging voltage, which is not possible with the conventional battery charger, and to perform activation charging of the battery 50.

  Furthermore, in order to reduce the load on the battery 50, charging in the vicinity of the supercritical charging voltage (strong constant current charging in the loop) and weak constant current charging are repeated, so the battery 50 is not damaged, rather Can eliminate symptoms such as sulfation and baria and extend battery life.

  In addition, as the charge termination condition, the following multiple monitoring parameters are set, and charging is terminated in an efficient manner in a short time by charging the battery when either of them is satisfied. The load on can be reduced.

(1) Ordinary full charge detection For example, when the battery 50 is fully charged by detecting the amount of charge, charging is completed for a predetermined time Tc using a timer after the full charge is detected. The charging can be terminated at the point in time.

(2) Detection of -ΔV2 When the maximum battery voltage at the nth charging is lower than the maximum battery voltage at the n-1th charging during the loop charging, the value is detected as -ΔV2. When -ΔV2 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 −ΔV2 becomes large, it can be determined that the battery cannot be charged any more, that is, the charging limit is reached. be able to.

  The set value of -ΔV2 can be set as appropriate depending on the type of battery and the rated voltage. For example, in the case of a battery with a rating of 48V, an average value of all cell voltages is 0.1V (as a battery voltage). 2 to 2.5V). The detection of -ΔV2 can occur in any of a lead battery, a nickel metal hydride battery, and a lithium ion battery.

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

  As described above, when −ΔV3 becomes large, it can be determined that the battery cannot be charged any more, that is, the state where the charging limit is reached. 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 with a rating of 48V, the average value of all cell voltages is 0.1V (as the battery voltage). 2 to 2.5V). The detection of -ΔV3 can occur in any of a lead battery, a nickel metal hydride battery, and a lithium ion battery.

(4) Detection of -ΔAH1 When the charge amount during the loop charge is smaller than the charge amount during the loop charge of the previous step, the difference is detected as -ΔAH1, and -ΔAH1 is greater than the predetermined allowable value. If it becomes larger, it is determined that the full charge condition is satisfied, and charging can be completed.

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

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

(1) Detection of -ΔV If the battery voltage drops during charging, the value is detected as -ΔV, and if this -ΔV is larger than a predetermined set value, it is detected as abnormal. , Stop charging.

  The set value of -ΔV can be set as appropriate according to the type of battery and the rated voltage. For example, in the case of a battery with a rating of 48V, the average value of all cell voltages is 0.1V (as the battery voltage). 2V to 2.5V). Note that detection of -ΔV in this way is particularly common in nickel metal hydride batteries.

(2) Detection of + ΔV If the battery voltage suddenly rises during constant voltage charging, the value is detected as + ΔV, and if this + ΔV is greater than a preset value, it is detected as abnormal. And stop charging.

  The set value of + ΔV can be set as appropriate depending on the type of battery and the rated voltage. For example, in the case of a battery with a rating of 48V, the average value of all cell voltages is 0.12V (the battery voltage is 3V). Degree). Such detection of + ΔV is particularly common in lithium ion batteries.

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

  The set value of + ΔA can be set as appropriate depending on the type of battery and the current value during constant current charging. For example, in the case of a battery with a rated capacity of 400 AH, it may be about 5 to 10 A. it can. Note that + ΔA is detected in this way, particularly in nickel metal hydride batteries.

(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 An 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 an abnormality and charging is stopped.

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

(7) Detection of Tlc A loop charging upper limit time Tlc during loop charging is set, and when the loop charging time exceeds the loop charging upper limit time Tlc, it is detected as an abnormality and charging is stopped. .

(8) Detection of Al During charging at a constant voltage, if the charging current falls below the lower limit current Al, it is detected as an abnormality and charging is stopped.

(9) Detection of Vo When a predetermined overvoltage monitoring start voltage V ₀ is set and the charging voltage does not increase to the full charge voltage Vc of the battery 50 even after a predetermined time has elapsed after reaching the overvoltage monitoring start voltage Vo Is detected as abnormal and charging is stopped.

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

  In the present embodiment, when the abnormality detection condition is satisfied, the loop charging S100 is terminated, and when the number of loop charging has not reached the predetermined number of steps in S155, the loop charging S100 is performed again. However, the charging itself may be stopped when it is dangerous to continue charging.

  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. For this reason, it is preferable that a predetermined charging transient time Tn is set and the charging end condition and the abnormality detection condition are not determined until the charging transient time Tn elapses from the start of charging.

  FIG. 6 is a graph comparing the charge acceptance characteristics of the battery 50 when charged with a conventional battery charger and the charge acceptance characteristics of the battery 50 when charged with the battery charger of this embodiment. FIG. 6A is a graph showing the relationship between the charge amount during charging and the voltage, and FIG. 6B is a graph showing the relationship between the discharge amount during discharge and the voltage.

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

V is a result of charging with a weak current, VV is a medium current, and VVV is a large current.
As shown in FIG. 6, it is possible to charge more effectively when charging with a medium current than when charging with a high current, and more when charging slowly with a weak current than when charging with a medium current. Can be charged effectively. That is, the charge acceptance performance is better when charging is performed slowly over a weak current.

  On the other hand, when the battery charger 50 of the present embodiment is used, even if charging is performed with a medium current at the time of initial strong constant current charging, charging is performed with a weak current using a conventional battery charger. More power can be charged and more power can be output than in the case of performing the above. That is, the charge acceptance performance is superior when charging is performed using the battery charger 10 of this embodiment, rather than charging slowly with a weak current using a conventional battery charger. This is an effect of slowly charging in the weak constant current charging in the loop in the supercritical charging state.

  In addition, in M which is the present embodiment, loop charging combining strong constant current charging and weak constant current charging is performed. For example, loop charging only with strong constant current charging (strong constant current charging and charging suspension) Repeat) or loop charge with only weak constant current charge (repetition of weak constant current charge and charge pause), the charge acceptance amount is estimated to be smaller than M in the present embodiment. That is, the battery can be activated most by loop charging combining strong constant current charging and weak constant current charging.

  FIG. 7 is a schematic configuration diagram for explaining the configuration of one 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.
In order to control the discharge of the battery 50 by the battery discharger 62, a control means may be provided in the battery discharger 62. In this embodiment, the battery discharger 62 is controlled by the control means 40 of the battery charger 10. It is configured to do.

  In order to be used as the battery diagnostic device 60 as in this embodiment, the control means 40 is achieved by controlling the battery charging means 20, the signal analyzing means 30, and the battery discharger 62 as follows. .

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

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

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

  In this way, by analyzing the change in the charging voltage while charging the battery 50, as shown in FIG. 9, when the charging of the battery proceeds, 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 that occurs in the change of the charging voltage for each cell, and the diagnosis of the battery 50 can be performed.

FIG. 10 is a schematic configuration diagram for explaining a configuration in an embodiment of the battery regenerator of the present invention.
Since the battery regenerator 70 can basically have the same configuration as the battery diagnostic unit 60 described above, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

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

With such a battery regenerator 70, it is possible to regenerate the battery so that it can be charged even with a battery that cannot be charged with a conventional charger.
Note that a capacitor may be connected in parallel to the battery cell to perform passive balancing.

As mentioned above, although the preferable Example of this invention was described, this invention is not limited to this,
In the above embodiment, the supercritical charging voltage of a lead battery and a nickel metal hydride battery is given as an example. However, in the battery charger, battery diagnostic device, and battery regenerator of the present invention, for example, a lithium ion battery, a nickel cadmium battery, etc. Can also be used.

  Further, as disclosed in Patent Documents 1 and 2, the present invention is configured to detect an abnormality, and when an excessive load is applied to the battery, the charging is immediately terminated to prevent the battery from being broken. Various modifications can be made without departing from the purpose.

DESCRIPTION OF SYMBOLS 10 Battery charger 20 Battery charging means 30 Signal analysis means 32 Abnormal alarm means 40 Control means 42 Data storage means 50 Battery 60 Battery diagnostic device 62 Battery discharge device 70 Battery regenerator

Claims (7)

Battery charging means for charging the connected battery;
Based on the charging signal sent from the battery charging means, signal analysis means for analyzing the battery,
Control means for controlling charging by the battery charging means based on the analysis result in the signal analyzing means;
A battery charger comprising:
The control means includes
A strong constant current charging step of performing 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 step for performing constant current charging with a current of 0.06 CA to 0.25 CA, and weak in-loop for 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 that alternately repeats the current charging step by a predetermined number of loops;
A constant voltage charging process for performing constant voltage charging;
The battery charger is configured to sequentially execute. The control means includes
The battery charger according to claim 1, wherein the battery charger is configured to multiplex the loop charging process. The control means includes
The preset charging end condition and abnormality detection condition are stored,
The strong constant current charging step, the weak constant current charging step, and the loop charging step are configured to end the step when the charge end condition or the abnormality detection condition is satisfied. The battery charger according to claim 1 or 2. The control means includes
In the strong constant current charging step and the weak constant current charging step, when it is determined that the charging voltage of the battery exceeds the full charging voltage of the battery, the step is terminated. The battery charger according to claim 3. The control means includes
In the in-loop strong constant current charging step and the in-loop weak constant current charging step, when it is determined that the charging voltage of the battery exceeds the supercritical charging voltage of the battery, the loop charging step is terminated. The battery charger according to claim 3 or 4, wherein the battery charger is configured. A battery charger according to any one of claims 1 to 5;
A battery discharger for discharging the battery;
With
The control means includes
Before the strong constant current charging step, performing a discharging step of discharging the battery for a predetermined time by the battery discharger,
The signal analysis means includes
While the strong constant current charging step, the weak constant current charging step, and the loop charging step are being performed, the charging voltage for each cell of the battery is measured,
A battery diagnostic device characterized by diagnosing the battery based on a change in the charging voltage. A battery charger according to any one of claims 1 to 5;
A battery discharger for discharging the battery;
With
The control means includes
A battery regenerator that regenerates the battery by repeatedly charging and discharging the battery using the battery charger and the battery discharger.

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