JP2000209786A - Charging/discharging device for electric power storing means and manufacture of electric power storing means using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To collectively charge a plurality of electric power storing means from an AC power source and collectively discharge the storing means to the power source by providing a plurality of power converters, one of the secondary windings of which are connected to the AC side of a transformer having secondary windings and the DC sides of which are respectively connected to a plurality of electric power storing means, to an AC power source. SOLUTION: A plurality of windings are connected in series on the primary side of a transformer 2 and AC power source 1 is connected to both ends of the connected windings. In addition, the secondary-side outputs of the transformer 2 are respectively outputted to a plurality of cells through (n) sets of AC-DC converters 3. The AC power source 1 converts a DC voltage which is obtained by rectifying the AC voltage of three-phase commercial power supply 101 by means of a rectifier diode converter 102 and smoothing the rectified voltage by means of a smoothing capacitor 103 into an AC voltage having a desired frequency by means of a full-bridge converter 104. Then the power source 1 converts the AC voltage into a DC voltage and supplies charging currents to secondary batteries 4-6. The secondary-side currents of the transformer 2 are collectively controlled by means of the converter 104 by making the primary-side current of the transformer 2 coincident with a command value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging / discharging device for power storage means and a method for manufacturing power storage means using the same.

[0002]

2. Description of the Related Art In a lithium ion secondary battery or a nickel hydride secondary battery, for example, a charging process of a unit cell, a charging and discharging process, etc. for the purpose of inspecting the assembled secondary battery or activating a chemical reaction. Is applied. Conventionally, in charging and discharging of batteries after such assembling, if a defective battery is detected, it is necessary to individually select the batteries.Therefore, an independent charging and discharging power supply is provided for each battery to perform charging and discharging. Running. In particular, in the case of a lithium ion secondary battery, it is necessary to perform not only constant current charging but also constant voltage charging at the time of charging, and therefore, an individual charging power supply system capable of setting a charging current and a charging voltage for each battery is used. . On the other hand, when each individual secondary battery is used as a storage battery for an electric vehicle or power storage, an assembled battery in which the cells are connected in series is connected. Charge and discharge to extract power. In addition, when charging or discharging batteries in a state of being connected in series, the same charging current flows through each battery. appear. In particular, in lithium ion secondary batteries,
It is necessary to charge each battery voltage while maintaining it below a predetermined value. For this reason, there is known a method of charging / discharging using assembled batteries in a multi-series state, as in the technique described in JP-A-8-88944. In order to suppress the variation of each battery in the series connection state, each battery is corrected by providing an individual power supply.

[0003]

However, when individual cells are charged or discharged by individual charging / discharging power supplies, a charging / discharging power supply proportional to the number of cells to be charged or discharged simultaneously is required. Become. In particular, in a charging / discharging device for the purpose of activating or inspecting a secondary battery after assembly, a series of charging / discharging processes takes several hours or more. It is necessary to charge and discharge a large number of cells at the same time using the charge / discharge power supply.
For this reason, there is a problem that a large number of individual charge / discharge power supplies are required, though each unit cell may be charged / discharged with the same current and voltage pattern.

Further, as in an application to an electric vehicle or a storage battery for storing electric power, a plurality of cells are connected in series to form an assembled battery. In this state, charging and discharging are performed by a power source for collective charging or discharging. In such a method, a circuit for bypassing a defective battery detected during charging / discharging is required for each individual battery. Also, in order to compensate for voltage variations due to variations in the capacity of individual cells and charge or discharge so that the voltage of each cell becomes uniform, a separate charge / discharge power source is required for each battery. Become. In particular, in the case of lithium ion secondary batteries, while accurately measuring each battery voltage,
It is necessary to execute charging and discharging. In a state where the individual cells are connected in series, the voltage of each cell must be detected by a differential potential, and there is also a problem that a circuit for voltage detection becomes complicated.

[0005] Further, when a plurality of batteries are connected in parallel and charged and discharged, charging and discharging may occur due to variations in the capacity of each battery.
Alternatively, the discharge current is not uniform, each battery cannot be fully charged, and an additional circuit for detecting and disconnecting a defective battery is required.

The present invention has been made in consideration of the above problems.

[0007]

According to the present invention, there is provided a charge / discharge device for power storage means, comprising: an AC power source; a transformer having a primary winding and a plurality of secondary windings to which the AC power source is connected; And a plurality of power converters, each of which is connected to one of the plurality of secondary windings, and each DC side is connected to one of the plurality of power storage means.

According to the present invention, since the power storage means is connected to each of the plurality of secondary windings of the transformer connected to the AC power supply, the AC power supply collectively charges or stores the power in the plurality of power storage means. Batch discharge from the means to the AC power supply becomes possible.

The charging / discharging device of the power storage means according to the present invention includes a device having a charging function, a device having a discharging function, and a device having both functions. As the AC power source, various types that output AC power can be used, but it is preferable that the AC power source has a power converter connected to the primary winding of the transformer. In this case, by controlling the power converter unit so that the current flowing through the primary winding becomes the current command value, charging or discharging of the plurality of power storage units can be controlled collectively. Further, examples of the power storage means include a secondary battery, an assembled battery in which a plurality of unit secondary batteries are connected in series, an electric double layer capacitor, a capacitor, and a fuel cell.

In the charging / discharging device for power storage means according to the present invention as described above, the AC power supply is provided with a power converter section, and further, an electric motor and an inverter supplied with power from the power converter section and driving the motor. , A motor drive system can be constructed. Further, in the charging / discharging device of the power storage means according to the present invention as described above, if an AC power supply is connected to a power system, a power storage system can be constructed.

Next, the method of manufacturing the power storage means according to the present invention comprises the first step of assembling the main bodies of the plurality of power storage means, and the plurality of power sources in the charging / discharging device of the power storage means as described above. A second step of connecting one of the assembled plurality of power storage means to each DC side of the converter, and initially charging the plurality of power storage means by the charging / discharging device of the power storage means according to the present invention. Charging, initial discharge, or aging.
ADVANTAGE OF THE INVENTION According to this invention, in a manufacturing process of a power storage means, it becomes possible to collectively perform initial charging or initial discharging or aging processing of a plurality of power storage means by an AC power supply. Preferably, the AC power supply has a power converter connected to the primary winding of the transformer. In this case, by controlling the power converter unit so that the current flowing through the primary winding becomes the current command value, it is possible to control the initial charging or initial discharging or the aging process of the plurality of power storage units collectively. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a first embodiment according to the present invention, a case in which n (n: 2 or more) secondary batteries are collectively charged will be described below with reference to FIG. In FIG. 1, an output of an AC power supply 1 is connected to a primary side of a transformer 2 as a transformer, and the transformer 2 outputs n secondary windings 201, 202, and 203. Here, the transformer 2 has primary windings of a plurality of transformers connected in series, and the output of the AC power supply 1 is applied to both ends of the primary winding. Each secondary output of the transformer 2 is output to a plurality of unit cells via an AC / DC converter 3 composed of n individual AC / DC converters. AC power supply 1
The AC voltage of the three-phase commercial power supply 101 is rectified by the rectifier diode converter 102 and the output is
Is obtained by converting a DC voltage obtained by smoothing the AC voltage into an AC voltage having a desired frequency by the full bridge converter 104. Here, the voltage of the commercial three-phase power supply is AC200
At V, the DC voltage is about 280V. The full-bridge converter is a semiconductor switching element I
It is constituted by a GBT (Insulated Gate Bipolar Transistor), and the frequency of the AC output voltage is 20 kHz.

The secondary circuit of the transformer 2 includes rectifier diode bridges 311, 321, 33 provided for each battery.
1, and reactors 312, 322, and 332 connected to the DC output of each diode bridge. The AC voltage on the secondary side of the transformer is converted into a DC voltage.
A charging current is supplied to each of the secondary batteries 4, 5, and 6. here,
When the turns ratio of the windings individually coupled on the primary side and the secondary side of the transformer is set to 1: a, the current of the primary side winding connected in series and the output of each output of the transformer secondary side are set. The ratio with the current is a: 1. The primary current of the transformer and the plurality of secondary currents flow while maintaining this relationship regardless of variations in each battery voltage, internal resistance, and the like. Therefore, by controlling the full-bridge converter 104 so that the primary current of the transformer matches a desired command value, the current on the secondary side of the transformer can be controlled collectively. In each of the secondary circuits, switches Y11, Y21, and Y31 for short-circuiting the outputs of the rectifier diode bridges 311, 321, and 331 and switches Y1 for disconnecting the batteries 4, 5, and 6 from each other.
2, Y22, and Y32, respectively, and individual control signals 313, 323, and 3 from the individual control device 304 are provided.
According to 33, these switches are turned on / off.

Next, operation waveforms are shown in FIG. The full bridge converter 104 outputs an alternating voltage having a high frequency of 20 kHz. As shown in FIG. 2A, by comparing a triangular carrier signal having the same frequency as the output frequency of the full-bridge converter 104 with a signal representing the positive voltage command and the negative voltage command, the gate of the IGBT is obtained. The drive signals s1, s2, s3, and s4 are obtained. Where s
1 and s3, s2 and s4 each have a non-lap period of about several μs in order to turn on / off complementarily.
By driving the IGBT of the full bridge converter 104 with this signal, an AC voltage shown in FIG. 2C is obtained. This AC output has a peak value of Vdc and a period of 50μ.
At s, the conduction ratio becomes a rectangular wave voltage proportional to the magnitude of the positive and negative voltage commands. FIGS. 3A and 3B show examples of AC voltage waveforms when the conduction ratio is changed. By applying this AC voltage to the primary side of the transformer 2, a voltage obtained by dividing the primary side voltage by the number n of multiple series is output to each secondary side output. The voltage sharing of the secondary side output is determined depending on each battery voltage and the like. This secondary voltage is rectified by the rectifier diode bridges 311, 321, and 331 and converted into a DC voltage.
2, 322, 332 to allow a charging current to flow. When viewed from the full bridge converter 104, the batteries of the secondary circuit of the transformer 2 are connected in series via an alternating current. Therefore, the current flowing to the primary side and the charging current to the batteries connected to each secondary circuit have a relationship of the turns ratio, and the charging current for each battery varies in battery voltage and internal resistance for each battery. Are equal. Therefore, by controlling the current of the full bridge converter 104, the charging current to each battery can be controlled. The waveforms of the AC current on the primary side of the transformer and the charging current to each battery at this time are shown in FIGS. Thus, the charging current and the AC current on the primary side of the transformer are obtained by turning on s4 and s1 or s2 and s3 in the gate signal to the full bridge converter 104.
Are matched during the period when they are on. Therefore, the alternating current is
As shown in (f), the current is detected by the current detector 105 (CT in this embodiment) in synchronization with the minimum amplitude point (valley of the triangular carrier signal) of the carrier signal for gate signal generation, and the detected value is obtained. By holding the current until the next detection point, the charging current to each battery can be detected from the AC current on the primary side of the transformer. By controlling the duty ratio of the full-bridge converter using the current detection value of the transformer primary side so that the current detection value becomes the charging current command value, the charging of the secondary battery connected to the transformer secondary side is performed. The current can be controlled to the same value of the charging current among the batteries even if there is a variation in the voltage and internal resistance of each battery. Here, since the secondary side of the transformer is insulated, each of the batteries can be individually grounded on one side of the terminal to a common potential, so that the battery voltage can be detected with respect to the common potential for each battery.

Next, in this embodiment, since the batteries are charged in a state of being connected in series via a transformer, if a defective battery is detected during charging, the battery is disconnected from the secondary circuit, and It is necessary to continue charging other batteries. In addition, when the battery voltage varies during charging, it is necessary to individually bypass the charging current of each battery and adjust the charging current for each battery. The operation waveform at this time is shown in FIG. Now, full bridge converter 104
Is the output current of Ic, and the charging current to each battery is I1, I2,
..., In. Here, the switch Y1 on each secondary circuit side
1, Y21 and Y31 are off and switches Y12 and Y2
2. When Y32 is on, each battery is charged normally.
On the other hand, by turning on the switch Y11 of the first secondary circuit, the corresponding secondary circuit can be short-circuited, the charging current flows to the switch Y11 side, and the battery 4 can be bypassed. After the bypass, by turning off the switch Y22,
The battery can be disconnected from the charging circuit. Here, a power MOSFET (Metal Oxide Semiconductor) is used as the switch Y11.
By using a semiconductor switching element such as an onductor field effect transistor), the bypass of each battery current can be finely controlled, thereby compensating the current of each secondary circuit. By turning on / off the switches Y11, Y21, Y31 individually, the full-bridge converter 10
4, the load varies, but by controlling the output current of the full-bridge converter 104, the output current of the full-bridge converter 104 can be controlled to a desired value.

As described above in detail, according to the present embodiment, a plurality of batteries on the secondary side of the transformer can be collectively charged in a series connection state by the transformer having the primary side connected in multiple series. There is an advantage that the circuit configuration is simplified as compared with the case where charging is performed individually with each power supply. Further, since the battery is charged in a state where the battery voltages are connected in series, there is an advantage that a plurality of batteries can be collectively charged without increasing the current, and the batch charging can be efficiently performed. Also, since the batteries connected to the secondary side of the transformer are each insulated,
The voltage of each battery can be measured against a common potential,
There is also an advantage that measurement of a plurality of battery voltages is easy. Also, by detecting the current on the primary side of the transformer in synchronization with the switching operation of the full-bridge converter, and using the result to control the magnitude of the output current of the full-bridge converter to match the desired charging current command value. There is an advantage that the charging current can be controlled collectively regardless of the number of secondary circuits. Further, since the value of the substantially middle point of the current ripple due to the duty ratio control of the full bridge converter can be detected as the current detection value, there is an advantage that the current detection in which the influence of the current ripple of the charging current is removed can be executed. Further, according to the present embodiment, any battery in which a failure is detected can be disconnected from the charging circuit even during charging, so that the defective battery can be disconnected while charging other batteries is continued. In addition, there is an advantage that the charging current of each battery is individually compensated for by using a function of bypassing the charging current, so that variations in battery voltage can be corrected.

Next, a second embodiment of the present invention will be described with reference to FIG. Reactors 312, 322, and 332 are connected to the outputs of each battery, 4, 5, and 6, respectively.
The output is converted to full bridge converters 315, 325, 3
At 35, the voltage is converted to an AC voltage and supplied to a plurality of secondary windings of a transformer. Here, the full bridge converter is constituted by a power MOSFET. Transformer 2
Primary windings are connected in series with the corresponding secondary windings, and the primary output voltage is
7. The booster chopper operation of the control circuit 108 reduces the power charged in each battery to the smoothing capacitor 10
3. Regenerate to the power supply 101 via the regenerative converter 109 and the reactor 110. FIG. 7 shows the gate signals of the full-bridge converters 315, 325, and 335 and the gate signal of the converter 107 for each battery at this time. As shown in FIGS. 7 (c) and 7 (d), converter 107 has a negative chopper cycle at a predetermined chopper cycle.
The gate signals s3 and s4 of the GBT element are turned on / off.
Here, during the ON period of s3 and s4, the battery on the secondary side of the transformer is in a short-circuit state via the reactors 312, 322 and 332. On the other hand, during the off periods of s3 and s4, the power accumulated in the reactor of each battery is reduced by the smoothing capacitor 103.
Released to the side. Here, the full bridge converters 315, 325, and 335 for each battery convert the DC voltage of each battery into an AC voltage having a fixed frequency and magnitude (the magnitude of the AC voltage is proportional to the battery voltage). Convert to
For this reason, as shown in FIGS. 7A and 7B, the same gate signal is given to the full-bridge converters of all the batteries in synchronization with the carrier signal for generating a gate signal of the converter 107. In addition, full bridge converter 315,
When the power MOSFETs 325 and 335 are turned on / off, a short-circuit period signal for short-circuiting the upper and lower arms is given. Thus, the current of the reactor of each battery can be controlled continuously even when the polarity of the AC current is switched between positive and negative. Further, by setting this short-circuit signal so as to synchronize with the on-period of the chopper control signal of converter 107, a short-circuit period for switching the polarity of the full-bridge converter can be provided in the on-period of the boost chopper. This allows
The battery voltage can be AC-converted for each battery without affecting the step-up chopper operation, and discharge can be performed collectively in a state where the batteries are connected in multiple series by the transformer 2. Also, at the time of discharging, in synchronization with the ON period of the boost chopper,
By detecting the AC current on the primary side of the transformer, a current value corresponding to the discharge current of each battery can be executed by detecting the current on the primary side of the transformer. These operations have the same relationship as the detection of the charging current from the primary side of the transformer during the batch charging.

As described in detail above, according to the second embodiment, the step-up chopper control can be executed in a state where the battery voltage is converted into an alternating current and the voltage is connected in series with a transformer. Batch discharge can be performed without providing a discharge power source for the battery, and batch discharge can be performed with simple control. In addition, by synchronizing the gate signal for boost chopper control and the gate signal with the full-bridge converter for converting each battery to AC voltage, the short circuit period accompanying the AC conversion of each battery voltage is affected. There is an advantage that the collective discharge can be performed without any problem.

A third embodiment of the present invention will be described with reference to FIG. Full-bridge converter 104 for batch charging and discharging, full-bridge converters 315, 325, 335 for each battery
However, this is different from the first and second embodiments. In this way, by using both converters as full-bridge converters and controlling gate signals for them, collective charge, collective charge, and separation of defective batteries, collective charge, individual charge control, collective discharge, collective Discharge and individual discharge control can be respectively performed.

As described above, according to the third embodiment, there is an advantage that the charge / discharge control in each operation mode can be switched and executed by controlling each gate signal with the same circuit configuration. .

A fourth embodiment of the present invention will be described with reference to FIG. This embodiment has a configuration in which an individual discharge power source 7 for each battery is added to the first embodiment shown in FIG.
The individual discharge power supply is connected between each output of the individual DC / AC converter 3 (that is, between terminals of each battery) and the smoothing capacitor 103. In addition, the individual discharge power supplies
It consists of a current-controlled insulated switching power supply. In the present configuration, at the time of charging, the batch charging current Ic2 for each battery is
Is supplied. On the other hand, an individual current command value is given to the individual discharge power supply, and Id1, Id2, Id3
Is regenerated from each battery to the smoothing capacitor side. Therefore, the charging current to each battery is a current obtained by subtracting the currents Id1, Id2, Id3 to the individual discharging power supplies from the collective charging current value Ic2. Thus, by operating the individual discharge power supply at the time of batch charging, the charging current of each battery can be corrected according to each battery capacity variation. On the other hand, when each battery is discharged, the discharge currents Id1, Id2, and Id3 can be regenerated from the batteries by the individual discharge power source 7 to the power source 101 side. Thereby, collective charging, individual charging control, and individual discharging can be performed. The operation waveform at this time is shown in FIG.

As described in detail above, according to the fourth embodiment, the compensation including the individual charging control at the time of the batch charging can be executed by the individual discharging power supply for discharging, so that the charging can be performed with a simple circuit configuration. Discharge control can be achieved. In addition, since an individual power supply having a large boost ratio is used for discharging, there is an advantage that discharge control of each battery can be performed in a wide battery voltage range including a state where the battery voltage is low.

Next, a fifth embodiment according to the present invention will be described with reference to FIG.
Shown in The difference from the fourth embodiment of FIG. 9 lies in that a power supply for individual discharge capable of discharging for each battery is added to a charge / discharge device capable of collectively charging / discharging. According to the present embodiment, since the power supply for individual discharge is added to the full-bridge converter capable of batch charge and collective discharge, the power capacity for individual discharge is suppressed to a small capacity that can correct the variation in battery capacity. There is an advantage that you can.

As described above, according to the fifth embodiment, there is an advantage that the power supply for individual discharge can be limited to a small capacity for correcting a variation in capacity.

FIG. 12 shows the configuration of the sixth embodiment according to the present invention.
Shown in In contrast to the third embodiment shown in FIG.
Of each converter 31 and the individual AC / DC converter 3
And the bidirectional chopper circuits 318, 328, and 338 connected between the batteries 4. Here, the transformer 8 has a configuration in which a plurality of secondary windings are connected in parallel to a primary winding, and the transformer 2 is connected in multiple series in the present embodiment, whereas the transformer 2 is connected in multiple series. ing. In the present embodiment, during charging, the AC output voltage of the full bridge converter 104 is output in parallel to a plurality of secondary windings. Here full bridge converter 1
An output voltage set value is instructed at 04, and an AC output voltage is output according to the set value. Individual AC / DC converter 3
Controls the charging and discharging of each battery by individually controlling the charging and discharging of each battery using each output voltage of the transformer 8 as an input. On the other hand, during discharging, the full bridge converter 104
The gate signal for each IGBT is turned off and operates as a rectifier diode bridge. The discharge current of each battery is converted into AC by an individual AC / DC converter 3, and the
Are connected in parallel. Full bridge converter 10
The discharge current of each battery is collectively regenerated to the smoothing capacitor 103 side by the rectifying diode operation of 4, and the power is regenerated to the commercial power supply 101 by the power regeneration converter 109.

FIG. 13 shows operation waveforms at the time of charging in this embodiment. The operations in FIGS. 13A to 13C are the same as those in the multi-series connection system in the first to fifth embodiments, but the output voltage command value for the full bridge converter 104 is directly given as the output voltage set value. Can be Here, the output voltage set value is set according to the magnitude of each battery voltage. That is, since the battery voltage is low at the beginning of charging, the full-bridge converter 1
The output voltage set value for the battery 04 is small, and near the full charge, the output voltage set value is large. On the other hand, in the individual charge / discharge control 307, the current detecting means 319, 329,
339, the charge / discharge current of each battery is detected, and the power of the positive side arm of the bidirectional chopper circuits 318, 328, 339 is detected.
, Mn1 are controlled. This operation waveform is shown in FIG. That is, an individual control amount is calculated as a result of the individual charge / discharge control 307 for each battery, and m1 is obtained by comparing the level with the sawtooth wave.
, Mn1 signals are obtained. Thereby, m1
During the period in which 1, m21,..., Mn1 are off, the AC voltage generated by the full-bridge converter 104 is turned off, so that the charging voltage can be corrected for each battery. The AC output waveform at that time is shown in FIG.
With respect to the output voltage of the full-bridge converter shown in FIG. 13C, the conduction ratio of the AC voltage is corrected by the individual correction amount shown in FIG. By performing this correction for each battery, variations in battery voltages, variations in transformer voltage sharing, and the like are corrected, and compensation is performed so that the charging current to each battery is maintained at a desired value. The waveform of the individual charging current at this time is shown in FIG. As a result, it is possible to constantly control the current flowing through the plurality of secondary circuits connected in multi-parallel via the transformer as in the present embodiment. Even when the charge current of each battery is corrected, the voltage adjustment function of the bidirectional chopper circuits 318, 328, 338 is used.
The charging current to each battery can be controlled.

On the other hand, FIG. 14 shows an operation waveform at the time of discharging.
Unlike the case of the third embodiment shown in FIG. 8, each full bridge converter 104 operates as a rectifier diode bridge, and the individual AC / DC converter 3 controls the discharge current for each battery by individual control for each battery. Control. Here, at the time of discharging, by turning on / off the gate signals m12, m22,..., Mn2 of the lower arms of the bidirectional chopper circuits 318, 328, 338 provided in the AC / DC converter 3, the battery voltage is reduced. The operation of lowering the voltage is performed. As a result, the discharge current can be individually controlled for each battery. The operation waveform at this time is shown in FIG. here,
The individual control amounts that give the duty ratios of the gate signals m12, m22,..., Mn2 are calculated as a result of the discharge current control in the individual charge / discharge control 307. As a result, collective discharge can be performed by the rectifying diode operation of the full bridge converter 104, and the gate signals m12, m22, and mn2 of the lower arms of the bidirectional chopper circuits 318, 328, and 338 are used.
Even if the battery voltage varies, the discharge current can be controlled to a desired constant value.

As described above in detail, according to the fifth embodiment, a plurality of batteries connected in multi-parallel via the transformer 8 can be charged / discharged collectively, so that the charge / discharge circuit configuration can be simplified. There is an advantage. Also, since the magnetic core can be integrally configured with a transformer in which a plurality of secondary windings are coupled in parallel with the primary winding, there is no need to provide a transformer in proportion to the number of secondary windings. There is also. Providing a bidirectional chopper circuit in each secondary circuit also has the advantage that the charge current and discharge current of each battery can be controlled according to desired command values and can be individually compensated.

Next, a method for manufacturing a secondary battery will be described as an embodiment of the present invention. In the secondary battery manufacturing process, initial charge, discharge, and aging are performed on the assembled battery.

The outline of the manufacturing process of the non-aqueous electrolyte secondary battery will be described below. Such a secondary battery is obtained by coating a positive electrode active material and a negative electrode active material on a predetermined foil, respectively, winding up with a separator in between, inserting into a predetermined can, filling with an electrolytic solution and sealing the can. Assembly is completed. Here, for the positive electrode, first, cobalt lithium lithium and a carbon material-based conductive agent are dissolved in an organic solvent to form a paste, and this mixture is applied to both sides of the aluminum foil. After drying, it is compressed by a roll press.

On the other hand, carbon or graphite is used for the negative electrode agent, and a mixture obtained by mixing with a binder is kneaded and paste, bound to a copper foil, and wound up similarly. Next, in a winding step, both electrodes are wound through a separator and cut. The wound electrode is housed in a battery can, welded to a sealing cap, injected with an electrolytic solution, and then sealed to complete the assembly process of the battery body.

The assembled battery is charged and discharged initially,
Further, an aging process in which the battery is left in a charged state is performed. That is, charging, discharging, and the like are performed on the assembled battery. After first charging to a predetermined voltage, discharging until reaching a predetermined voltage, and then leaving. This provides a method for manufacturing a nonaqueous electrolyte secondary battery capable of confirming the capacity and suppressing deterioration of the charge / discharge cycle of the battery after aging.

The initial charge / discharge device according to the present invention has the advantage that such charge / discharge control can be performed collectively. Here, the charging / discharging characteristics of the multiple batteries are executed as described below. At the time of initial charging, a plurality of test batteries are mounted on the charging / discharging device. The charging / discharging device supplies a charging current to a plurality of batteries according to a predetermined charging current command value. During charging, each battery voltage is measured by the voltage detecting means of the charging / discharging device, and the individual battery voltages sequentially form a charging current bypass circuit from a battery that has reached a predetermined set voltage, and are collectively arranged. The battery voltage can change the current command value for each battery with respect to the charging current. Here, the charging current is set to a constant value on the batch converter side, and is sequentially disconnected from the charging circuit from the charged battery to the predetermined value, and the charging is completed to the last one charged battery. . As a result, at the time of charging and also at the time of discharging, collective discharge control can be performed in a state where each battery voltage is kept constant.

Next, after charging a plurality of battery voltages to a predetermined voltage value, the initial charging is completed, and then the initial discharging is performed.
The discharging is continued until each battery voltage decreases to a predetermined voltage. At this time, the discharge is continued so that the discharge current command value becomes a discharge current common to each battery. Here, even if the battery is discharged with the same discharge current due to variations in battery capacity, etc.,
A difference occurs in the time required to reach the discharge completion voltage.
Also in this case, similarly to the individual disconnection at the time of charging, the battery that has been discharged to the predetermined discharge end voltage is disconnected from the collective discharge state by discharging. This is because, by turning on the bypass circuit on the individual converter side, the discharge current can be bypassed for the corresponding battery, whereby the discharge of each battery can be completed to the discharge end voltage. After the batch charge, discharge, and processing are completed, the battery is disconnected from the charge / discharge circuit and the aging process is started. Next, the voltage that has been reduced during the aging period is charged again to complete the charge / discharge process.

As described in detail above, according to the charging / discharging apparatus or method according to the present invention, in the battery manufacturing process,
Batch initial charge / discharge processing and aging processing can be performed.

Next, as an embodiment of the present invention, a charging / discharging apparatus for assembled batteries connected in multiple series is shown in FIGS. The configuration of the charging / discharging device is the same as that of any of the embodiments described above, except that the battery pack is charged / discharged with respect to the unit cell. In the embodiment of FIG. 15, the assembled batteries are connected in multiple series via a transformer 2 and a full bridge converter 1 is connected.
04 collectively charges and discharges. In the embodiment of FIG. 16, the assembled batteries are connected in multi-parallel via the transformer 8, and are charged and discharged collectively by the full bridge converter 104. FIG.
In the seventh embodiment, the battery packs connected in multiple series via the transformer 13 are connected in multiple parallel, and the full-bridge converter 104 charges and discharges all at once. As described above, even when the cells are assembled batteries connected in multiple series, there is an advantage that a plurality of assembled batteries can be charged / discharged with a simple configuration by collectively charging / discharging via a transformer.

Next, as another embodiment of the present invention, an application example to an electric vehicle is shown in FIGS. In FIG. 18, a plurality of assembled batteries 9, 10, 11 are connected in multiple series via a transformer 2. By discharging the energy of the assembled battery by the collective converter 12, the electric power of the battery is supplied to the induction motor via the converter 12 and the inverter 13 connected to the DC side of the converter 12 via the inverter 13, so that the electric vehicle is driven. Drive. On the other hand, by supplying a DC voltage to the collective converter 12 by the charger 15, the collective converter 12 charges each battery with the charging current via the transformer 2. FIG.
Shows a case where multiple parallel connections are made. According to the present embodiment,
Since a plurality of assembled batteries can be combined and charged and discharged in an insulated state, there is an advantage that the assembled batteries can be divided and managed, and can be individually replaced. Further, there is an advantage that the voltage and the total capacity of the assembled battery can be limited by dividing the assembled battery.

The embodiments shown in FIGS. 18 and 19 can be applied to not only electric vehicles but also various induction motor driving systems. The system according to the present embodiment can be applied to not only an induction motor but also a motor driven by an inverter such as a brushless motor.

Next, as another embodiment of the present invention, an application example to an electric power storage system is shown in FIGS. FIG.
1, the battery packs 9, 10, and 11 serving as power storage means are connected in multiple series by a transformer 2 and linked to a power system 16 via a batch converter 1. FIG. 21 shows a case where the transformer 8 is connected in multiple parallel. According to the present embodiment, there is an advantage that each battery pack is divided and arranged, and replacement for each battery pack is easy.

[0040]

According to the present invention, two or more secondary batteries and their assembled batteries can be charged / discharged collectively, so that individual cells or assembled batteries can be operated by individual charge / discharge power supplies. The charging / discharging device can be configured with a simpler configuration as compared with the case where charging and discharging are performed individually. Further, in the batch charging, since the batteries can be charged or discharged in a state of being connected in multiple series or multiple parallel, charging or discharging can be performed with the output voltage of the charging / discharging converter being high. For this reason, the current capacity of the power element constituting the converter and the copper loss due to the current flowing through the converter can be reduced, and an effective charge / discharge power supply can be formed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a charging power supply according to a first embodiment.

FIG. 2 is an operation waveform of a charging power supply according to the first embodiment.

FIG. 3 is an operation waveform of a charging power supply according to the first embodiment.

FIG. 4 is an operation waveform of a charging power supply according to the first embodiment.

FIG. 5 is an operation waveform of a charging power supply according to the first embodiment.

FIG. 6 is a configuration diagram of a discharge power supply according to a second embodiment.

FIG. 7 is an operation waveform of a discharge power supply according to the second embodiment.

FIG. 8 is a configuration diagram of a charge / discharge power supply according to a third embodiment.

FIG. 9 is a configuration diagram of a charge / discharge power supply according to a fourth embodiment.

FIG. 10 shows operation waveforms of the charge / discharge power supply according to the fourth embodiment.

FIG. 11 is a configuration diagram of a charge / discharge power supply according to a fifth embodiment.

FIG. 12 is a configuration diagram of a charge / discharge power supply according to a sixth embodiment.

FIG. 13 shows operation waveforms of the charge / discharge power supply according to the sixth embodiment.

FIG. 14 is an operation waveform of the charge / discharge power supply according to the sixth embodiment.

FIG. 15 is a charging / discharging apparatus for a battery pack according to an embodiment of the present invention.

FIG. 16 is a battery pack charging / discharging apparatus according to an embodiment of the present invention.

FIG. 17 shows a battery pack charging / discharging device according to an embodiment of the present invention.

FIG. 18 is an example of application to an electric vehicle according to an embodiment of the present invention.

FIG. 19 shows an application example to an electric vehicle which is an embodiment of the present invention.

FIG. 20 is an application example of a power storage system according to an embodiment of the present invention.

FIG. 21 is an application example of a power storage system according to an embodiment of the present invention.

[Explanation of symbols]

1. AC power supply 2. Multi-series connected transformer 3. AC / DC converter

Continued on the front page (72) Inventor Kiichi Tokunaga 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Hideki Miyazaki 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture No. 7 Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Akihiko Emori 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory Hitachi, Ltd. EA09 FA06 GA01 GB06 5H030 AA10 AS03 AS08 BB01 BB21

Claims (10)

[Claims] An AC power supply; a transformer having a primary winding to which the AC power supply is connected and a plurality of secondary windings; each AC side being connected to one of the plurality of secondary windings. And a plurality of power converters each of which has a DC side connected to one of the plurality of power storage means. 2. The power supply according to claim 1, wherein the AC power supply has a power converter connected to the primary winding, and the power converter is configured to control a current flowing through the primary winding to a current command value. A charging / discharging device for power storage means, characterized in that the charging / discharging device is controlled as follows. 3. The charging / discharging device for power storage means according to claim 1, wherein said transformer has a plurality of transformer primary windings connected in series. 4. The power converter according to claim 1, wherein the plurality of power converters convert AC power output from the plurality of secondary windings into DC power, and the plurality of power converters are converted by the DC power. A charging / discharging device for a power storage means, wherein the storage means is charged. 5. The AC power supply according to claim 1, wherein the DC power discharged from the plurality of power storage means is converted into AC power by the plurality of power converters, and the AC power is supplied through the transformer. A charge / discharge device for power storage means, wherein the charge / discharge device is regenerated. 6. The AC power supply according to claim 4, further comprising: a power supply connected to one of the plurality of power storage means and discharging from the one of the plurality of power storage means. A charge / discharge device for power storage means, comprising: a plurality of discharge means for regenerating power. 7. The method according to claim 1, wherein each of the plurality of power storage means is a secondary battery, an assembled battery in which a plurality of unit secondary batteries are connected in series, an electric double layer capacitor, a capacitor, and a fuel cell. A charging / discharging device for power storage means, which is any one of the above. 8. An electric motor, an inverter for driving the electric motor, an AC power supply including a power converter unit for supplying electric power to the inverter, a primary winding and a plurality of secondary windings to which the AC power supply is connected. And a plurality of power converters, each AC side of which is connected to one of the plurality of secondary windings, each of which is connected to one DC side of the plurality of power converters. An electric motor drive system, comprising: a plurality of connected power storage units. 9. An AC power supply connected to an AC power system, a transformer having a primary winding and a plurality of secondary windings to which the AC power supply is connected, and a plurality of secondary windings each having an AC side. A plurality of power converters connected to one of the plurality of power converters, and a plurality of power storage units each connected to a DC side of one of the plurality of power converters. Storage system. 10. A first step of assembling a plurality of power storage units, an AC power supply, a transformer having a primary winding to which the AC power supply is connected, and a plurality of secondary windings; And a plurality of power converters, the sides of which are connected to one of the plurality of secondary windings, wherein the plurality of power converters are assembled on the DC side of each of the plurality of power converters. A second step of connecting one of the power storage units; and a third step of performing an initial charge, an initial discharge, or an aging process on the plurality of power storage units by the charging / discharging device. Manufacturing method of power storage means.