JP4151662B2 - Control method and control device for charge voltage equalization circuit of battery pack - Google Patents

Description

  The present invention relates to a control method and a control device for a charge voltage equalization circuit of an assembled battery.

Recently, as a secondary battery used in a hybrid vehicle or an electric vehicle, a lithium battery has attracted attention because it has a high energy density, can be reduced in size and weight, and has less heat generation. However, in a hybrid vehicle or an electric vehicle, it is necessary to drive a driving motor with electric power, so the battery must be set to a high voltage (about 300V). Creating voltage.
In order to improve the battery life and efficiently use the extracted power, it is necessary to maintain the charging voltage of the battery within a certain range. In particular, when an assembled battery is composed of a lithium battery using an organic electrolyte, charging between unit cells due to a sealing phenomenon such as a nickel cadmium battery or a nickel metal hydride battery using a water-soluble electrolyte. Since there is no equalization effect that equalizes the voltage, even if the charge voltage at both ends of the assembled battery in which a large number of cells are connected in series is controlled, the charge voltage of each individual cell will vary depending on its characteristics and ambient temperature. Due to the difference, it does not converge to the same value, but varies and overcharged and overdischarged cells appear. For this reason, when an assembled battery is constituted by a lithium battery, a method of controlling the charging voltage of the assembled battery and simultaneously controlling the charging voltage of a single cell is employed.

For example, in Patent Document 1, a plurality of cells are connected in series to constitute a block, and a plurality of blocks are further connected to constitute a set of assembled battery modules. Then, the charge voltage of the single cell is equalized for each block, and the voltage of each block is also equalized for the block.
As a method of equalization, as shown in FIG. 8, a method is adopted in which cells having a high voltage are discharged so as to align with the voltages of the cells having a low voltage. FIG. 8 shows an example of equalization of a single cell in one block, and it can be seen that the charge voltage of 7 cells varies is equalized to the cell having the lowest charge voltage. It is to be noted that the equalization of each cell group is equalized to the lowest voltage block as in the case of equalization of a single cell.
Here, the invention disclosed in Patent Document 1 is characterized in that the cell discharge current for equalizing the cell voltage is made larger than the block discharge current for equalizing the blocks. This is because by making the cell discharge current larger than the block discharge current, the cell voltage is adjusted to a predetermined voltage earlier than the block voltage, which is efficient and can suppress unnecessary discharge of the cell.
Japanese Patent Application No. 2004-225827

However, in the case of the above conventional example, if the cell equalization discharge circuit has an abnormality (contact failure, disconnection, ON fixation, etc.) and the voltage of a specific cell in the block decreases, the cell equalization in the block is Since the other cells are discharged so as to be aligned with the cell having the lowest charging voltage, all the cells in the block continue to be discharged as shown in FIG. 9, and the block voltage is also lowered. It will be. Furthermore, since the equalization is performed for each block, the discharge is repeated so as to match the voltage of the abnormal block where the voltage decreases, and the voltage of the assembled battery module does not converge and continues to decrease abnormally.
Further, in the equalization in each block, the block equalization is performed according to the block including the abnormal cell. However, as shown in FIG. 6B, the voltage difference between the normal block and the abnormal block gradually widens as shown in FIG. Reaches the upper and lower limits of the SOC control range, and the battery cannot be charged / discharged.

  The present invention has been made to solve the above problems, and in the case where the cell voltage in the block is excessively decreased due to poor contact, disconnection, sticking, or other abnormality of the cell equalization discharge circuit. Another object of the present invention is to provide a control method and a control device for an equalized charge / discharge circuit of an assembled battery that suppresses voltage variation between blocks, approximates normal equalization operation, and maintains the performance of the assembled battery. .

In order to achieve the above-mentioned object, the invention of claim 1 is configured such that a plurality of chargeable / dischargeable cells are connected in series to form a block, and a plurality of the blocks are connected in series to form an assembled battery. In a control method of a charge voltage equalization circuit for a battery pack having a cell equalization circuit that discharges to align the charge voltage in cell units, and a block equalization circuit that discharges to equalize the charge voltage in block units, When the variation in charge voltage of each block is within a predetermined value, the discharge current of the cell equalization circuit is set larger than the discharge current of the block equalization circuit, and the variation in the charge voltage is equal to or greater than a predetermined value In this case, the discharge current of the cell equalization circuit is set to be equal to or lower than the discharge current of the block equalization circuit.

According to the control method of the equalized charging / discharging circuit of the assembled battery according to claim 1 , the charging voltage of each block is compared, and when the variation in the charging voltage is within a certain range, all the cells are in a normal state. Since it is determined that the cell equalization discharge current is set to be larger than the block equalization discharge current, the cell voltage equalization is performed earlier than the equalization between the blocks and ends earlier. An unnecessary voltage drop of the cell can be prevented.
Furthermore, when the variation in the charging voltage of each block being monitored exceeds a certain range, it is determined that there is an abnormality in the cell equalizing discharge circuit of the block where the voltage drop is significant, so the cell equalizing discharge circuit Is set to be equal to or less than the discharge current of the block equalization discharge circuit to prevent excessive discharge of the block having the cell equalization discharge circuit in an abnormal state, and thus abnormal decrease in the charge voltage of the entire assembled battery This makes it possible to operate normally as an assembled battery.

  According to the invention of claim 3, a plurality of chargeable / dischargeable cells are connected in series to form a block, and a plurality of the blocks are connected in series to form an assembled battery, and the charging voltage is arranged in units of each block. In a control apparatus for a charge voltage equalization circuit for an assembled battery having a cell equalization circuit for discharging the battery and having a block equalization circuit for discharging to equalize the charge voltage in units of blocks, the charge voltage of each block When the variation is within a predetermined value, the discharge current of the cell equalization circuit is set larger than the discharge current of the block equalization circuit, and when the variation in the charging voltage is equal to or greater than the predetermined value, the cell equalization Discharge current switching means for setting the discharge current of the circuit to be equal to or lower than the discharge current of the block equalizing circuit is provided.

  The control device for the equalized charge / discharge circuit of the assembled battery according to claim 3 detects an abnormality of the cell equalization discharge circuit according to the degree of variation in the charge voltage of each block, and discharges the cell equalization discharge circuit and the block equalization circuit. Since a switch or other means is provided to control the switching of the magnitude of the current, when normal, priority is given to cell voltage equalization to suppress unnecessary discharge of cells and to operate efficiently, and there is an abnormality in the cell equalization circuit. In the case of occurrence, the switch is configured to change the magnitude relationship of the discharge current to prevent an abnormal voltage drop of the corresponding block and to enable normal operation as an assembled battery.

According to a second aspect of the present invention, in the method for controlling a charge voltage equalizing circuit for an assembled battery according to the first aspect, the cell is a lithium battery. The invention of claim 4 is the control device of the charging voltage equalizing circuit of the assembled battery according to claim 3, wherein the cell is characterized by a lithium battery.

As described above, lithium batteries are attracting attention for use in hybrid vehicles and electric vehicles. However, if they are not used within a certain charging voltage range, the lithium batteries cannot fully function, and in some cases may cause cell failure. .
According to the present invention, it is possible to accurately control the charging voltage of a lithium battery to achieve efficient operation and long life of the battery.

  As described above, according to the control method and the control device for the charge voltage equalization circuit of the assembled battery of the present invention, the charge voltage of the battery of the assembled battery is controlled within a predetermined range to efficiently operate the assembled battery. At the same time, even if the cell continues to discharge due to an abnormality in the cell equalization circuit, the battery voltage is prevented from dropping abnormally, and the normal operation is performed even when there is an abnormality. Can continue.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a control method and a control device for an assembled battery charge voltage equalization circuit according to the present invention will be described below based on Example 1 and Example 2 that refer to an assembled battery charge voltage equalization circuit of a hybrid vehicle. .
(Example 1)
FIG. 1 shows an example of a schematic configuration of an apparatus to which a method for controlling an equalization charge / discharge circuit of a battery pack according to the present invention is applied. 1 is a charge voltage equalization circuit, 2 is a cell equalization circuit, 3 Is a block equalization circuit. A block equalization circuit control unit 4 is connected to the block equalization circuit 3. Reference numeral 5 is an inverter, 6 is a motor generator, and 10 is an assembled battery.
The assembled battery 10 is configured by connecting block 1, block 2,..., Block n in series.
Each block has a plurality of single cells connected in series. In addition, the positive electrode terminal A and the negative electrode terminal A ′ of the assembled battery 10 are connected to the motor generator 6 via the inverter 5.
The cell equalization circuit 2 includes a cell equalization circuit (1), a cell equalization circuit (2),..., A cell equalization circuit (n), and the block equalization circuit 3 includes a block equalization circuit (1), The block equalizing circuit (2),..., Is composed of a block equalizing circuit (n).

In this configuration, the cell equalization circuit (1) to the cell equalization circuit (n) are connected to the corresponding block 1 to block n, respectively, and a high voltage is set so that the charging voltage for each cell is made uniform in each block. It is a circuit that discharges and equalizes cells.
The block equalization circuit (1) to the block equalization circuit (n) are connected to the corresponding blocks 1 to n, respectively, detect the voltages of the blocks 1 to n, and control the block equalization circuit. This is a circuit that discharges and equalizes high voltage blocks so that the voltages of the blocks 1 to n are made uniform based on the command of the unit 4.

Next, a specific configuration of the cell equalization circuit 2 will be described. Since the cell equalization circuit (1) to the cell equalization circuit (n) all have the same configuration, the cell equalization circuit (2) will be described.
FIG. 2 shows the cell equalization circuit (2) connected to the block 2 constituting the assembled battery 1.
The cell equalization circuit (2) includes a block voltage dividing circuit 20, comparison circuits 21 to 23, logic circuits 24 and 25, transistors 21 to 24, resistors R21 to 24, and a cell discharge inhibition circuit 26. It is configured.
In this embodiment, the block 2 to which the cell equalization circuit (2) is connected is a unit in which four unit cells (C21 to C24) are connected in series.

  The block voltage dividing circuit 20 is configured by connecting resistors 20a to 20d having the same resistance value in series. One end of the resistor 20a is connected to the positive terminal of the block 2 and one end of the resistor 20d is connected to the negative terminal. With this configuration, the voltage of the block 2 is equally divided according to the number of cells, and is output as an average cell voltage of the block 2 to the comparison circuits 21 to 23.

The comparison circuits 21 to 23 and the logic circuits 24 and 25 compare the cell voltages of the cells C21 to C24 with the average cell voltage output from the block voltage dividing circuit 20, and control the transistors TR21 to TR24 to turn on / off the average cell. This is a circuit for discharging a cell having a voltage higher than the voltage.
The two input terminals (Er1, Ec1) of the comparison circuit 21 are connected to the connection point of the resistors 20a and 20b and the negative terminal of the cell C21, respectively. The comparison circuit 21 is based on the two input data, and the transistor TR21. ON / OFF control is performed to discharge and adjust the voltage of the cell C21.
Similarly, the comparison circuit 23 inputs and compares the cell voltage of the cell C24 and the average cell voltage output from the block voltage dividing circuit 20, and based on the result, the transistor TR24 is controlled to be turned on / off to control the cell C24. Adjust the voltage by discharging.

The logic circuit 24 performs ON / OFF control of the transistor TR22 based on the outputs of the comparison circuits 21 and 22, and discharges and adjusts the voltage of the cell C22. The input terminals S1L and S1H of the logic circuit 24 are connected to the output terminals S1L and S1H of the comparison circuit 21, and the input terminals S2L and S2H are connected to the output terminals S2L and S2H of the comparison circuit 22, respectively. The output terminal SD2 is connected to the transistor TR22.
Similarly, the logic circuit 25 controls ON / OFF of the transistor TR23 based on the outputs of the comparison circuits 22 and 23 to discharge and adjust the voltage of the cell C23.

The transistors TR21 to TR24 are switching elements for discharging the cells C21 to C24 by short-circuiting based on outputs of the comparison circuits 21 to 23 and the logic circuits 24 and 25. The resistors R21 to R24 are current limiting elements for limiting the discharge current when the transistors TR21 to TR24 short-circuit the cells C21 to C24 to discharge them.
The base of the transistor TR21 is the output terminal S1L of the comparison circuit 21, the base of TR22 is the output terminal SD2 of the logic circuit 24, the base of TR23 is the output terminal SD3 of the logic circuit 25, and the base of TR24 is the output terminal of the comparison circuit 23. Each is connected to S3H, and performs a switching operation based on the output of the comparison circuit or the logic circuit.

  The cell discharge inhibition circuit 26 is a circuit that inhibits the discharge of the cells C21 to C24 by turning off the transistors TR21 to TR24 based on a command from the block equalization circuit control unit 4. The cell discharge inhibition circuit 26 includes diodes 26a to 26d, resistors 26e to 26h, and a photocoupler 26i. The anode of the diode 26a is connected to the connection point between the output terminal S1L of the comparison circuit 21 and the transistor TR21. The anode of the diode 26b is connected to the connection point between the output terminal SD2 of the logic circuit 24 and the transistor TR22, and the anode of the diode 26c is connected to the connection point of the output terminal SD3 of the logic circuit 25 and the transistor TR23. The anode of the diode 26d is connected to the connection point between the output terminal SD3 of the logic circuit 25 and the transistor TR23. The cathode of each diode is connected to a photocoupler 26i via resistors 26e to 26h. The input terminal of the photocoupler 26 i is connected to the block equalization circuit control unit 4, one end of the output terminal is connected to the resistors 26 e to 26 h, and the other end is connected to the negative terminal of the block 2.

Next, a specific configuration of the block equalization circuit 3 will be described. FIG. 3 shows the block equalization circuit 3 connected to the blocks 1 to n constituting the assembled battery 10.
As shown in FIG. 3, the block equalization circuit 3 includes block voltage detection circuits VSG1 to VSGn, transistors TR1 to TRn, resistors R1 to Rn, and photocouplers PC1 to PCn.

The block voltage detection circuits VSG1 to VSGn are circuits provided in the corresponding blocks 1 to n, respectively, and detect the voltage of each block and send it to the block equalization circuit control unit 4.
Two input terminals of the block voltage detection circuits VSG1 to VSGn are connected to the positive and negative terminals of the blocks 1 to n, respectively. The outputs of the block voltage detection circuits VSG1 to VSGn are connected to the block equalization circuit control unit 4 via the output terminals OUT1 to OUTn.

The transistors TR1 to TRn are switching elements for short-circuiting and discharging the blocks 1 to n, and the resistors R1 to Rn are respectively connected when the transistors TR1 to TRn short-circuiting the blocks 1 to n and discharging. It is a current limiting element for limiting the discharge current flowing through the block. The bases of the transistors TR1 to TRn are connected to the output terminals of the photocouplers PC1 to PCn, the collectors are connected to the positive terminals of the blocks 1 to n via the resistors R1 to Rn, and the emitters are connected to the negative terminals of the blocks 1 to n, respectively. Yes.
The photocouplers PC1 to PCn are connected at their input terminals to the decoder output of the block equalization circuit control unit 4, and based on the output of the block equalization circuit control unit 4, the transistors TR1 to TRn are ON / OFF-controlled elements. And the output end are electrically disconnected.

  As shown in FIG. 4, the specific configuration of the block equalization circuit control unit 4 includes a multiplexer 41, an AD converter 42, a microcomputer 43, and a decoder 44.

The multiplexer 41 is a circuit that inputs the detection voltages of the blocks 1 to n, selects one of them, and sends it to the AD converter 42. Input terminals VSIN1 to VSINn of the multiplexer 41 are connected to output terminals VSOUT1 to VSOUTn of the block voltage detection circuits VSG1 to VSGn, respectively.
The AD converter 42 AD converts the detection voltages of the blocks 1 to n selected by the multiplexer 41 and outputs the converted voltages to the microcomputer 43.

The microcomputer 43 determines a block to be discharged based on the input detection voltages of the block voltage detection circuits VSG1 to VSGn, and outputs it to the decoder 44 for ON / OFF control of the transistors TR1 to TRn as switching elements. To do. Output terminals POUT1 to POUTn of the decoder 44 are respectively connected to PIN1 to PINn which are input terminals of the photocouplers PC1 to PCn of the block equalization circuit 3.
The microcomputer 43 also controls the operation of the cell equalization circuit 2 based on the operation state of the ignition switch and the current value flowing through the assembled battery. Further, the microcomputer 43 also sends out data related to the assembled battery 10 based on the detection voltage of each block, the output of the cell equalization circuit, and the current value.
In addition to the detection voltages of the block voltage detection circuits VSG <b> 1 to VSGn, the microcomputer 43 takes in data on the operation state of the ignition switch and the current value of the assembled battery from the IG terminal and IB terminal. Data on the assembled battery is output from the CMD terminal.

Next, the operation of the invention according to claims 1 and 3 of the present application will be described based on the first embodiment.
A hybrid vehicle travels with the driving force of the engine when traveling at a constant speed with good engine operation efficiency. At this time, when it is determined that the charge amount of the assembled battery is insufficient, the control unit of the vehicle is driven by the engine using the motor generator 6 as a generator in the configuration of the charge voltage equalization circuit of the assembled battery in FIG. Then, the battery pack 10 is controlled to be charged via the inverter 5.
On the other hand, during start-up or full acceleration when the engine operation efficiency is not good, the vehicle travels by driving the motor generator 6 using the assembled battery 10 as a power supply source and the motor as a motor.
Therefore, the assembled battery is charged during constant speed running by the engine, and the charge voltage equalization of the assembled battery is mainly performed while the vehicle is stopped.

FIG. 5 shows the main parts of the cell equalization circuit and the block equalization circuit according to the first and third aspects of the present invention. FIG. 5 shows the discharge of the cell equalization circuit connected to the block 1 and the block equalization circuit. The form of is shown. The block 1 is composed of n single cells connected in series.
The cell equalization circuit compares the cell average voltage in the block with each cell voltage. When the cell voltage is higher than the cell average voltage, the cell equalization circuit operates the discharge circuit provided for each cell (for example, cell 1). R11 and TR11) Finally, all the cells in the block are equalized to the cell average voltage.
As shown in FIGS. 1 and 3, the block equalization circuit is provided with a voltage detection circuit and a discharge circuit for each of a plurality of blocks, and the block equalization circuit controller detects the voltage with the voltage detection circuit. Based on the voltage of each block, each block is discharged so that the voltage is aligned with the block having the lowest voltage to equalize the block voltage.

At this time, the cell (and a) equalizing the discharge current has the following advantages if it is set to be equal to or less than the block equalizing the discharge current (a b).
Figure 6 is a comparison of charge and discharge characteristics of the battery pack system of the present invention and the conventional example in which the abnormality in the cell equalization circuit occurs, FIG. 6 (a), the battery pack system according gun onset bright FIG. 6B shows the charge / discharge characteristics of a conventional assembled battery system. The graph of FIG. 6 shows charge / discharge operations of a typical normal block and an abnormal block among a plurality of blocks for easy understanding. The vertical axis of the graph represents the SOC (charge rate) of the block, and the horizontal axis represents time.
In FIG. 6A, equalization is performed during the first stop (time: 0 → t1). However, since the normal block has high SOC (voltage is high), discharge by the block equalization circuit is performed. on the other hand,
In the abnormal block, the SOC is low (the voltage is low), so that the discharge by the block equalization circuit is not performed, but the discharge by the cell equalization is performed. However, since the cell equalization discharge current is set to be equal to or less than the block equalization discharge current, the SOC decrease rate of the abnormal block is smaller than the SOC decrease rate of the normal block, and the time 0 → t1 During this period, the difference in SOC between both blocks becomes small. Next, during the time t1 → t2, the vehicle is charged while traveling, but since the charging currents flowing through the normal block and the abnormal block are the same, the SOC increase rate is the same as shown in the figure. In the next equalization operation from time t2 to time t3, the difference in SOC between both blocks is further reduced. In this way, the equalization and charging are repeated, and the SOCs of both blocks operate in the direction of convergence.
Therefore, the normal block does not discharge excessively in accordance with the voltage drop of the abnormal block, and operates so that the voltage of the abnormal block approaches the voltage of the normal block, so that the normal function of the assembled battery system can be maintained. .

  In the conventional example shown in FIG. 6B, since the cell equalization discharge current is set to be larger than the block equalization discharge current, normalization is performed during the first stop (time: 0 → t1). The SOC difference between the block and the abnormal block is widened, and the SOC difference is further widened by equalization at the next stop (time: t1 → t2). In this case, if both blocks are normal, equalization by the cell equalization circuit ends when equalization to the lowest voltage cell is made, and no further voltage drop occurs, but there is an abnormality in the cell equalization circuit. When this occurs, cell equalization discharge is further performed as shown in the figure, and the SOC of the abnormal block continues to decrease. Eventually, the upper and lower limits of the SOC control range are reached, and the battery cannot be charged or discharged.

(Example 2)
Next, a second embodiment according to the first and third aspects of the invention will be described with reference to FIG. The configuration of the battery pack system in which the second embodiment is implemented is the same as that of the first embodiment and is the configuration shown in FIG.
The second embodiment is different from the first embodiment in that discharge current switching means 31 to 3n are provided in the block equalization circuit 3 as shown in FIG. The same reference numerals are used for circuits or elements common to the first embodiment. Further, with respect to the configuration and operation, the description of the parts common to the first embodiment is omitted except for the parts necessary for the description of the second embodiment.

FIG. 7 shows the block equalization circuit 3 connected to the assembled battery. For the blocks 1 to n constituting the assembled battery, block equalization circuits (1) to (n) are respectively provided. The block equalization circuit includes an equalization discharge circuit and block voltage detection.
If the equalization discharge circuit is, for example, the block equalization circuit (1), the resistor R1, the discharge current switching means 31, and the transistor TR1 are connected in series. The output terminal of the photocoupler PC1 is connected to the base of the transistor TR1, and is driven ON / OFF based on a control signal from the block equalization circuit control unit 4.
The discharge current switching means 31 has a resistor R1a and a switch SW1 connected in parallel, one end connected to the resistor R1, and the other end connected to the collector of the transistor TR1. The switch SW1 is connected to the input terminal SIN1, and the input terminal SIN1 is connected to an output terminal (not shown) of the block equalization circuit controller 4.
The switch SW1 can use the same element as the switching transistor TR1.

Next, the operation of the second embodiment will be described.
In the configuration of FIGS. 1 and 7, when the cell equalization circuit is normal and the battery pack charge voltage equalization circuit is operating normally, the switches SW1 to SWn are open (OFF). Therefore, for example, in the block equalization circuit (1) connected to the block 1, the resistor R1, the resistor R1a, and the transistor TR1 are connected in series. Here, the resistor R1 and the resistor R1a are set so that the block discharge current of the block 1 determined by the combined resistance of the resistor R1 and the resistor R1a is smaller than the cell discharge current.
However, when the detected voltages of the block voltage detection circuits VSG1 to VSGn are compared and monitored by the block equalization circuit control unit 4, when the variation in the detection voltage of each block becomes a predetermined value or more, the discharge current Since the switches SW1 to SWn of the switching means are closed (turned on) on the basis of a command from the block equalization circuit controller 4, the discharge current of each block is determined by the resistors R1 to Rn, respectively. The resistors R1 to Rn are set so that the discharge current of each block is smaller than the cell discharge current.

That is, when the charge voltage equalization circuit is in a normal state, the cell equalization discharge current is set to a value larger than the block equalization discharge current, so that the cell equalization is performed earlier than the block equalization and unnecessary cell It prevents discharge and protects the cell and operates the battery pack efficiently.
However, if the cell voltage continues to drop excessively due to an abnormality in the cell equalization circuit and the voltage of the corresponding block also decreases, the block equalization circuit control unit detects the abnormal drop in the block voltage and Switching the magnitude relationship between the equalization discharge current and the block equalization discharge current, the control of the charge voltage equalization circuit of the assembled battery is brought close to the normal operation, and the normal operation as the assembled battery system can be continued. .

  In the second embodiment, the discharge current switching means is provided in the block equalization circuit 3, but the cell equalization circuit 2 is provided to change the cell equalization discharge current and the block equalization discharge current. The magnitude relationship may be switched. Further, the discharge current switching means may be provided in both the block equalization circuit 3 and the cell equalization circuit 2.

  Further, in the first and second embodiments, the unit cell unit of the cell equalization circuit is targeted to a single cell, but a plurality of single cells are connected in series to form a small block of cells. One equalizing discharge circuit may be connected to the block.

It is explanatory drawing which shows the schematic whole structure in embodiment of this invention. 3 is a circuit diagram of a cell equalization circuit according to Embodiment 1. FIG. FIG. 3 is a circuit diagram of a block equalization circuit according to the first embodiment. FIG. 3 is a block diagram of a block equalization circuit control unit according to the first embodiment. It is explanatory drawing of the cell equalization discharge current of Example 1, and a block equalization discharge current. It is explanatory drawing of the charging / discharging equalization operation | movement of the assembled battery of this invention and a prior art example. FIG. 6 is a circuit diagram of a block equalization circuit according to a second embodiment. It is explanatory drawing of the normal cell equalization operation | movement of a prior art example. It is explanatory drawing of the abnormal cell equalization operation | movement of a prior art example.

Explanation of symbols

1: Charge voltage equalization circuit 2: Cell equalization circuit 3: Block equalization circuit 4: Block equalization circuit control unit 5: Inverter 6: Motor generator 10: Battery pack 20: Block voltage division circuit 21-23: Comparison circuits 24 and 25: Logic circuit 26: Discharge inhibition circuit 31 to 3n: Discharge current switching means 41: Multiplexer 42: AD converter 43: Microcomputer 44: Decoder VSG1 to VSGn: Block voltage detection circuit

Claims (4)

  Cell equalization in which a plurality of chargeable / dischargeable cells are connected in series to form a block, and a plurality of the blocks are connected in series to form an assembled battery, and each block is discharged to equalize the charging voltage in units of cells. In a control method of a charge voltage equalization circuit of an assembled battery having a circuit and a block equalization circuit that discharges in order to align the charge voltage in units of blocks,
  When the variation in charge voltage of each block is within a predetermined value, the discharge current of the cell equalization circuit is set larger than the discharge current of the block equalization circuit, and the variation in the charge voltage is equal to or greater than a predetermined value When the discharge current of the cell equalization circuit is set to be equal to or lower than the discharge current of the block equalization circuit, the control method of the charge voltage equalization circuit of the assembled battery. 2. The method for controlling a charge voltage equalization circuit for an assembled battery according to claim 1, wherein the cell is a lithium battery. Cell equalization in which a plurality of chargeable / dischargeable cells are connected in series to form a block, and a plurality of the blocks are connected in series to form an assembled battery, and each block is discharged to equalize the charging voltage in units of cells. In a control device for a charge voltage equalization circuit of an assembled battery having a circuit and having a block equalization circuit that discharges to equalize the charge voltage in units of blocks,
When the variation in charge voltage of each block is within a predetermined value, the discharge current of the cell equalization circuit is set larger than the discharge current of the block equalization circuit, and the variation in the charge voltage is equal to or greater than a predetermined value In this case, the control device for the charge voltage equalization circuit of the assembled battery, comprising discharge current switching means for setting the discharge current of the cell equalization circuit to be equal to or lower than the discharge current of the block equalization circuit.   The said cell is a lithium battery, The control apparatus of the charging voltage equalization circuit of the assembled battery of Claim 3 characterized by the above-mentioned.

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