JP5960070B2 - Power supply - Google Patents

Description

  The present invention relates to a power supply device applied to a power supply system including a plurality of assembled batteries as a series connection body of unit batteries which are one or a plurality of adjacent battery cells.

  Conventionally, as seen in the following Patent Document 1, it is applied to a power supply system including a plurality of batteries, and the connection states of these batteries are connected in series or in parallel according to the required voltage of the inverter that is the power supply destination of these batteries. 2. Description of the Related Art A power supply device including a plurality of switches for switching to is known.

JP 2008-67432 A

  By the way, when the connection state of a plurality of batteries is switched from a series connection to a parallel connection by operating a plurality of switches, if the difference in the voltage between the terminals of the plurality of batteries is large, the voltage between the terminals is high from the battery with the low voltage between the terminals. A large current can flow to the battery. At this time, the reliability of the battery may be reduced.

  The present invention has been made to solve the above-described problems, and the object thereof is applied to a power supply system including a plurality of assembled batteries, and the reliability of the assembled batteries is reduced when the assembled batteries are switched to parallel connection. An object of the present invention is to provide a power supply device that can suitably avoid this.

In order to solve the above problems, the present invention provides an assembled battery (10 as a series connection body of unit batteries (Cij; i = 1, 2: j = 1 to N) which are one or a plurality of adjacent battery cells. , 20), and a charge / discharge circuit (Spij, 40) having power storage means (40, 40a, 40b) for storing electrical energy, and transferring charges between the power storage means and the unit cell. Snij, Lα, Lβ) and switching means (R1 to R4) for switching the connection state of the plurality of battery packs in order to connect at least two of the battery packs in series or in parallel, and the switching means Prior to switching the battery pack to parallel connection, battery pack equalization means for equalizing the voltage between the terminals of the battery packs to be switched to parallel connection via the power storage means is provided. .

  In the above invention, by providing the assembled battery equalizing means, it is possible to equalize the inter-terminal voltages of the assembled batteries switched to parallel connection before switching at least two of the plurality of assembled batteries to parallel connection. For this reason, when an assembled battery is switched to parallel connection, it can be avoided that a large current flows from an assembled battery having a high inter-terminal voltage to an assembled battery having a low inter-terminal voltage, and thus a decrease in reliability of the assembled battery can be avoided. .

  Furthermore, in the said invention, in order to equalize the voltage between terminals of the assembled batteries which divert the charging / discharging circuit which has an electrical storage means, and switch to parallel connection, the number of additional components for equalizing the said voltage between terminals is reduced. You can also

1 is a system configuration diagram according to a first embodiment. FIG. The flowchart which shows the procedure of the cell voltage equalization process concerning the embodiment. The flowchart which shows the procedure of the serial connection switching process concerning the embodiment. The flowchart which shows the procedure of the parallel connection switching process and battery voltage equalization process concerning the embodiment. The flowchart which shows the procedure of the charging voltage gradual increase process concerning the embodiment. The flowchart which shows the procedure of the charging voltage gradual reduction process concerning the embodiment. The time chart which shows the battery voltage equalization process concerning the embodiment. The time chart which shows the battery voltage equalization process concerning the embodiment. The system block diagram concerning 2nd Embodiment. The system block diagram concerning 3rd Embodiment. The time chart which shows the ground-fault current suppression process concerning the embodiment. The system block diagram concerning 4th Embodiment. The flowchart which shows the procedure of the output voltage adjustment process concerning the embodiment.

(First embodiment)
Hereinafter, a first embodiment in which an electric power supply device according to the present invention is applied to an electric vehicle including only a rotating machine as an in-vehicle main unit will be described with reference to the drawings.

  As shown in FIG. 1, the first battery 10 and the second battery 20 can be electrically connected to an inverter 32 (three-phase inverter) via a main relay SMR and a smoothing capacitor 30. Here, the inverter 32 has a function of converting DC power supplied from the first battery 10 and the second battery 20 into AC power and supplying the AC power to the motor generator 34 (three-phase rotating machine). Further, the main relay SMR has a function of electrically opening and closing between the first battery 10 and the second battery 20 and the inverter 32. The main relay SMR is closed (on) by, for example, turning on an ignition switch by a user of the vehicle. Incidentally, the rotor of the motor generator 34 is connected to the drive wheels 36.

  The first battery 10 and the second battery 20 are assembled batteries constituting an in-vehicle high voltage system and serving as a power source for the motor generator 34 and the like. The first battery 10 and the second battery 20 are a series connection body of a plurality of adjacent single cells (battery cells), and the voltage between the terminals becomes a predetermined high voltage (for example, several hundred volts). Here, the voltage between terminals of one battery cell is, for example, several volts. In addition, the negative terminal of the second battery 20 is connected to a grounding part (for example, a part having a vehicle body potential). In the present embodiment, the number of battery cells constituting each of the first battery 10 and the second battery 20 is set to be equal to each other, so that the terminal voltages of these batteries 10 and 20 are set to be equal to each other. ing. In the present embodiment, lithium ion secondary batteries are used as the first battery 10 and the second battery 20.

  Incidentally, in the present embodiment, hereinafter, the battery cells constituting the first battery 10 are referred to as 1j battery cells (j = 1 to N), and the battery cells constituting the second battery 20 are referred to as 2j batteries. It will be referred to as a cell.

  The power supply device includes a charge / discharge circuit. The charge / discharge circuit includes a capacitor 40 as “electric storage means”, a first electric path Lα, a second electric path Lβ, a p-side switching element Spij (i = 1, 2) as “positive electrode side opening / closing means”, and An n-side switching element Snij as “negative electrode side opening / closing means” is provided. Specifically, the first electric path Lα is connected to one end of the capacitor 40, and the second electric path Lβ is connected to the other end. The path connecting the positive electrode terminal of the ij-th battery cell Cij and the first electrical path Lα is provided with the ij-th p-side switching element Spij that opens and closes the path, and the ij-th battery cell Cij A path connecting the negative electrode terminal and the second electrical path Lβ is provided with an ij-th n-side switching element Snij that opens and closes the path. Incidentally, the capacitance of the capacitor 40 is such that when the charging voltage of the capacitor 40 matches the normal terminal voltage of the first battery 10 or the second battery 20, the first battery 10 or the second battery 20. The charging energy amount is set to be very small.

  In the present embodiment, a pair of N-channel MOSFETs whose sources are short-circuited with each other are used as the switching elements Spij and Snij. Here, the short circuit between the sources is a setting for facilitating an on operation or an open operation (off operation) of the pair of N-channel MOSFETs. In other words, since the N-channel MOSFET is turned on / off by the gate potential with respect to the source, the sources of the pair of N-channel MOSFETs can be made the same by short-circuiting the sources, and thus the on / off operation can be performed in a single manner. Can be performed by an open / close operation signal (voltage signal).

  The signal line Li (j + 1) is connected to the positive terminal of the ijth battery cell Cij, and the signal line Lij is connected to the negative terminal of the ijth battery cell Cij. That is, except for the signal lines Li1 and LiN, the signal line on the negative terminal side of the battery cell on the high potential side and the signal line on the positive terminal side of the battery cell on the low potential side among the adjacent battery cells are shared. Has been. Note that the voltage of the ij-th battery cell Cij is taken into the control circuit 38 via the signal lines Lij and Li (j + 1).

  Then, the structure for switching the connection state of the 1st battery 10 and the 2nd battery 20 is demonstrated.

  In the present embodiment, a pair of connection points (hereinafter referred to as a first connection point TL1 and a second connection point TL2) are provided on both sides of the main relay SMR on the side opposite to the inverter 32. When the first battery 10 and the second battery 20 are connected in series, the positive terminal of the first battery 10 that is the assembled battery on the highest potential side is connected to the first connection point TL1, The negative terminal of one battery 10 is connected to a second connection point TL2 via a fourth relay R4 described later. In addition, between the first battery 10 and the second battery 20 that are adjacent to each other, a gap between the negative terminal of the first battery 10 and the positive terminal of the second battery 20 is “first opening / closing means”. It is opened and closed by the first relay R1.

  The positive electrode terminal of the second battery 20 and the first connection point TL1 are opened and closed by a second relay R2 as “second opening / closing means”. In addition, the negative electrode terminal of the second battery 20 and the second connection point TL2 are opened and closed by a third relay R3 as “third opening / closing means”. Furthermore, the negative electrode terminal of the first battery 10 and the second connection point TL2 are opened / closed by the fourth relay R4 as “fourth opening / closing means”.

  The control circuit 38 is mainly composed of a microcomputer, and turns on and off the ijth p-side switching element Spij, the ijth n-side switching element Snij, the first to fourth relays R1 to R4, and the main relay SMR. .

  Next, the cell voltage equalization process according to the present embodiment will be described with reference to FIG. This process is a process for reducing variations in the voltage between terminals of N battery cells constituting each of the first battery 10 and the second battery 20 in order to increase the cruising distance of the vehicle.

  FIG. 2 shows the procedure of the cell voltage equalization process. This process is repeatedly executed by the control circuit 38 at a predetermined cycle, for example, in different periods for the first battery 10 and the second battery 20.

  In this series of processes, first, in step S10, the voltages Vi1 to ViN of the N battery cells Ci1 to CiN are detected.

  In subsequent step S12, based on the detection value in step S10, the battery cell having the highest voltage between terminals (hereinafter referred to as the highest voltage cell Cmax) and the voltage between terminals being the lowest among N battery cells Ci1 to CiN. A battery cell (hereinafter, the lowest voltage cell Cmin) is selected.

  In subsequent step S14, it is determined whether or not the potential difference between the inter-terminal voltage Vmax of the highest voltage cell Cmax and the inter-terminal voltage Vmin of the lowest voltage cell Cmin exceeds a specified value Ve (> 0). This process is a phenomenon in which the voltage between the terminals of the battery cell fluctuates (hunting) when the process is executed in a situation where the variation in the voltage between the terminals of the battery cell is small and it is not necessary to execute the cell voltage equalization process. ).

  If an affirmative determination is made in step S14, the process proceeds to step S16, and a plurality of battery cells Cdis that are power supply sources including the highest voltage cell Cmax are selected. In the present embodiment, three battery cells including the highest voltage cell Cmax are selected as the battery cell Cdis of the power supply source. Specifically, when the highest voltage cell Cmax is Cir (r = 1, 2,..., N), basically, the highest voltage cell Cir and a pair of battery cells Ci (r) adjacent to the highest voltage cell Cir. -1) and Ci (r + 1) are selected as the battery cells Cdis of the power supply source. However, when “r = 1” (the highest voltage cell Cmax is Ci1), there is no battery cell adjacent to the negative electrode terminal side of the highest voltage cell Cmax. Select Ci3. Further, when “r = N” (the highest voltage cell Cmax is CiN), there is no battery cell adjacent to the positive electrode terminal side of the highest voltage cell Cmax, and therefore, the battery cell Ci ( N-2) to CiN are selected. In the present embodiment, the process of this step and step S12 constitutes “unit battery selection means”.

  By selecting a plurality of power supply source battery cells Cdis in this step, the charging current supplied from the capacitor 40 to the power supply destination battery cell can be increased during the discharge process described later, and the battery cell terminal It is possible to shorten the time required for equalizing the inter-voltage.

  In the subsequent step S18, the charging process of the capacitor 40 is started. Here, the charging process turns on the p-side switching element connected to the positive electrode terminal and the n-side switching element connected to the negative electrode terminal of both ends of the series connection body of the battery cells of the selected power supply source. It becomes processing to do. Here, for example, the charging process when the highest voltage cell Cmax is the battery cell Ci (N−1) is performed by the iNth p-side switching element SpiN and the i (N−2) th nth switching element Sni ( N-2) is turned on. Accordingly, the battery cell Ci (N-2) to CiN are connected in series, the iN-th p-side switching element SpiN, the first electric path Lα, the capacitor 40, the second electric path Lβ, and the i (N-2). ) Of the n-side switching element Sni (N-2) is formed, and charging of the capacitor 40 is started.

  In subsequent step S20, the process waits until the first specified time T1 elapses after the charging process in step S18 is started. Here, the first specified time T1 is set to a time when it is assumed that the charging of the capacitor 40 is completed by the electric energy of the battery cell Cdis of the power supply source. Specifically, it can be set by the method described below.

  The voltage V (t) between terminals of the capacitor 40 can be expressed by the following equation (eq1), and the charging current i (t) of the capacitor 40 can be expressed by the following equation (eq2).

上式（ｅｑ１），（ｅｑ２）において、「Ｖ０」はコンデンサ４０の端子間電圧の初期値を示し、「Ｅ」は電力供給元の電池セルＣｄｉｓの端子間電圧を示し、「ｔ」はコンデンサ４０の充電処理が開始されてからの経過時間を示し、「Ｒ」は充電処理時に形成される上記閉回路の抵抗（電力供給元の電池セルＣｄｉｓの内部抵抗、スイッチング素子ＳｐｉＮ，Ｓｎｉ（Ｎ−２）のオン抵抗、配線抵抗及びコンデンサ４０のＥＳＲを含む抵抗）を示し、「Ｃ」はコンデンサ４０の静電容量を示す。

In the above equations (eq1) and (eq2), “V0” indicates the initial value of the voltage across the capacitor 40, “E” indicates the voltage across the battery cell Cdis as the power supply source, and “t” indicates the capacitor. 40 represents the elapsed time since the start of the charging process, and “R” represents the resistance of the closed circuit formed during the charging process (the internal resistance of the battery cell Cdis of the power supply source, the switching elements SpiN, Sni (N− 2), the on-resistance, the wiring resistance, and the resistance including ESR of the capacitor 40), and “C” indicates the capacitance of the capacitor 40.

  Here, according to the above equations (eq1) and (eq2), the transition of the inter-terminal voltage v (t) of the capacitor 40 and the charging current i (t) of the capacitor 40 since the charging process is started is grasped. Can do. Therefore, for example, the first specified time T1 can be set based on the time constant “RC” (more specifically, for example, the first specified time T1 can be set to the time constant “RC”). In addition, for example, in the above equation (eq2), the time calculated under the condition “i (t) = 0” can be set as the first specified time T1.

  In the subsequent step S22, the charging process of the capacitor 40 is completed by switching the switching element turned on in the process of step S18 to the off operation.

  In the subsequent step S24, the discharging process of the capacitor 40 is started. In the present embodiment, the power supply destination battery cell is only the minimum voltage cell Cmin. Then, in the discharge process, when the lowest voltage cell Cmin of the power supply destination is Ciq (q = 1, 2,..., N), the iqth p-side switching element Spiq and the iqth n-side switching element Sniq are turned on. It becomes processing to do. Here, for example, the discharge process when the lowest voltage cell Cmin is the battery cell Ci1 is a process of turning on the i1th p-side switching element Spi1 and the i1th n-side switching element Sni1. Accordingly, a closed circuit including the capacitor 40, the first electric path Lα, the i1th p-side switching element Spi1, the battery cell Ci1, the i1th n-side switching element Sni1 and the second electric path Lβ is formed, and the capacitor The electric energy stored in 40 is discharged and the battery cell Ci1 is charged.

  Incidentally, in the discharge process, the battery cell as the power supply destination may overlap with some of the battery cells Cdis as the power supply source.

  In subsequent step S26, the process waits until the second specified time T2 elapses after the discharge process in step S24 is started. Here, the second specified time T2 is set to a time when it is assumed that charging of the minimum voltage cell Cmin is completed by the electrical energy stored in the capacitor 40. Specifically, the second specified time T2 can be set by a method similar to the method described in the previous step S20. Here, in the above formulas (eq1) and (eq2), the initial value “V0” of the terminal voltage of the capacitor 40 and the terminal voltage “E” of the battery cell are interchanged.

  In subsequent step S28, the discharge process is terminated by switching the switching element turned on in the process of step S24 to the off operation.

  If a negative determination is made in step S14, or if the process in step S28 is completed, this series of processes is temporarily terminated.

  By the way, the cell voltage equalization process is actually a process for reducing variations in voltage between terminals of modules connected in series of a plurality of adjacent battery cells, and between battery cells constituting each of these modules. And processing for reducing variations in the voltage between terminals. For this reason, in this embodiment, a battery cell or a module corresponds to a “unit battery”. Here, the equalization of the inter-terminal voltage between the modules is performed by the same method as the equalization of the inter-terminal voltage between the battery cells, and thus detailed description thereof is omitted.

  Next, the connection state switching process according to the present embodiment will be described.

  This process is performed in accordance with the required output of the motor generator 34 in order to switch the connection state of the first battery 10 and the second battery 20 from series connection to parallel connection, or from parallel connection to series connection. The relays R1 to R4 and the like are turned on / off.

  First, the serial connection switching process for switching the first battery 10 and the second battery 20 from the parallel connection to the serial connection in the connection state switching process will be described with reference to FIG. FIG. 3 is a flowchart showing the procedure of the above process. This process is repeatedly executed by the control circuit 38 at a predetermined cycle, for example. The situation in which this process is executed is a situation in which the first battery 10 and the second battery 20 are connected in parallel. Here, the situation where these batteries 10 and 20 are connected in parallel is a situation where the first relay R1 is turned off and the second to fourth relays R2 to R4 are turned on.

  In this series of processes, first, in step S30, it is determined whether or not there is a serial connection request for the first battery 10 and the second battery 20. Here, whether or not there is a serial connection request may be determined based on, for example, whether or not the required output of the motor generator 34 is equal to or higher than the first predetermined output.

  If an affirmative determination is made in step S30, the process proceeds to step S32 to turn off the main relay SMR.

  In subsequent step S34, the second relay R2 and the fourth relay R4 are turned off. In step S36, the first relay R1 is turned on. Accordingly, the first relay R1 and the third relay R3 are turned on, and the second relay R2 and the fourth relay R4 are turned off, so that the first connection point TL1 and the second connection point TL2 are turned on. As a pair of terminals, the connection state of the first battery 10 and the second battery 20 is switched from parallel connection to series connection. Incidentally, in the present embodiment, the processes of steps S34 and S36 constitute “first operation means”.

  In the subsequent step S38, the main relay SMR is turned on.

  If a negative determination is made in step S30, or if the process in step S38 is completed, this series of processes is temporarily terminated.

  Subsequently, in the connection state switching process, the parallel connection switching process for switching the first battery 10 and the second battery 20 from the serial connection to the parallel connection, and the battery voltage equalization executed prior to switching from the series connection to the parallel connection Processing will be described. The battery voltage equalization process is performed between terminals of the batteries 10 and 20 on the condition that the absolute value of the difference between the voltage between the terminals of the first battery 10 and the voltage between the terminals of the second battery 20 exceeds the threshold voltage. This is a process for reducing variations in voltage. This process is a process for avoiding a large current flowing through the closed circuit including the batteries 10 and 20 when the connection state of the batteries 10 and 20 is switched from the serial connection to the parallel connection.

  FIG. 4 shows the procedure of the parallel connection switching process and the battery voltage equalization process. This process is repeatedly executed by the control circuit 38 at a predetermined cycle, for example.

  In this series of processing, first, in step S40, it is determined whether or not there is a parallel connection request. Here, whether or not there is a parallel connection request may be determined based on, for example, whether or not the request output of the motor generator 34 is less than the second predetermined output. Note that the second predetermined output and the first predetermined output may be set to the same value, or the second predetermined output may be set to a value slightly lower than the first predetermined output.

  If an affirmative determination is made in step S40, the process proceeds to step S42, and the main relay SMR is turned off. In step S44, the first relay R1 and the third relay R3 are turned off.

  In the subsequent step S46, the voltage V1 between the terminals of the first battery 10 (potential difference between the negative terminal of the eleventh battery cell C11 and the positive terminal of the first N battery cell C1N), and the voltage between the terminals of the second battery 20. V2 (potential difference between the negative terminal of the twenty-first battery cell C21 and the positive terminal of the second N battery cell C2N) is detected, and whether or not the absolute value of the voltage difference ΔV between these terminals exceeds the threshold voltage Vth. to decide. Here, the threshold voltage Vth is set from the viewpoint that the current flowing between the batteries 10 and 20 is sufficiently small when the connection state of the first battery 10 and the second battery 20 is switched to parallel connection, Specifically, for example, it is set to about the voltage between terminals of one battery cell.

  If an affirmative determination is made in step S46, it is determined that the variation in the voltage between the terminals of the first battery 10 and the second battery 20 is large, and the process proceeds to step S47. In step S47, an assembled battery (hereinafter referred to as a high voltage battery) having the highest inter-terminal voltage from among the first battery 10 and the second battery 20 based on the sign of the inter-terminal voltage difference ΔV, and the inter-terminal voltage An assembled battery having the lowest voltage (hereinafter referred to as a low voltage battery) is selected. In this embodiment, the process in this step constitutes “assembled battery selection means”.

  In a succeeding step S48, it is determined whether or not the value of the determination flag F is “0”. Here, the determination flag F indicates that a charging voltage gradual increase process, which will be described later, has not been executed yet by “0”, and indicates that the charging voltage gradual increase process has been completed by “1”.

  When an affirmative determination is made in step S48, the process proceeds to step S50, and charging voltage gradual increase processing is performed. This process is a process of gradually increasing the number of battery cells constituting the high-voltage battery to the capacitor 40 prior to the battery voltage equalization process. This process is a process for avoiding an excessive current flowing in a closed circuit including the high voltage battery and the capacitor 40 when the capacitor 40 is charged by the high voltage battery. That is, for example, when the p-side switching element connected to the positive terminal of the high-voltage battery and the n-side switching element connected to the negative terminal are turned on, the difference between the terminal voltage of the high-voltage battery and the terminal voltage of the capacitor 40 Therefore, there is a concern that an excessive current flows in a closed circuit including the switching element, the high voltage battery, and the capacitor 40. In order to avoid this, charging voltage gradual increase processing is performed.

  FIG. 5 shows the procedure of the charging voltage gradual increase process. This process is repeatedly executed by the control circuit 38 at a predetermined cycle, for example. In this embodiment, this process constitutes “gradual increase means”.

  In this series of processes, first, in step S100, the p-side switching element Spd1 connected to the positive terminal of the battery cell on the lowest potential side constituting the high-voltage battery, and the n-side connected to the negative terminal of the battery cell. The switching element Snd1 is turned on.

  In the subsequent step S102, the parameter k is set to “2”. In step S104, it is determined whether or not the parameter k has exceeded “N”, which is the number of battery cells constituting the high voltage battery.

  If a negative determination is made in step S104, the process proceeds to step S106, and p-side switching connected to the positive terminal of the “k−1” -th battery cell from the lowest potential side among the battery cells constituting the high-voltage battery. The element Spd (k−1) is turned off. In step S108, the p-side switching element Spdk connected to the positive terminal of the kth battery cell from the lowest potential side among the battery cells constituting the high voltage battery is turned on.

  In the subsequent step S110, the process waits until the third specified time T3 elapses after the on-operation of the p-side switching element Spdk is started by the process in step S108. Here, the third specified time T3 is the time when the charging of the capacitor 40 is completed by the electric energy of the series connection body of k battery cells from the low potential side among the battery cells constituting the high voltage battery. Set to Specifically, the third specified time T3 can be set by a method similar to the method described in the process of step S20 of FIG.

  In the subsequent step S112, the parameter k is incremented by 1, and the process returns to step S104.

  If an affirmative determination is made in step S104, the process proceeds to step S114, and the p-side switching element SpdN connected to the positive terminal of the battery cell on the highest potential side among the battery cells constituting the high-voltage battery is the lowest. The n-side switching element Snd1 connected to the negative terminal of the potential-side battery cell is turned off.

  In addition, when the process of step S114 is completed, this series of processes is once complete | finished.

  Returning to FIG. 4, the value of the determination flag F is set to “1” in step S50 after the charging voltage gradual increase process is completed.

  In subsequent step S52, the p-side switching element SpcN connected to the positive electrode terminal of the battery cell on the highest potential side among the battery cells constituting the low voltage battery and the negative electrode terminal of the battery cell on the lowest potential side are connected. The n-side switching element Snc1 is turned on.

  In subsequent step S54, the process waits until the fourth specified time T4 elapses after the switching element SpcN, Snc1 is turned on by the process in step S52. Here, the fourth specified time T4 is set to a time when it is assumed that charging of the low voltage battery is completed by the electric energy stored in the capacitor 40. Specifically, the fourth specified time T4 can be set by a method similar to the method described in the process of step S26 of FIG.

  In subsequent step S56, the switching elements SpcN and Snc1 that have been turned on in the process of step S52 are turned off. Thereafter, the process returns to step S46.

  On the other hand, if it is determined in step S48 that the charging voltage gradual increase process has been completed, the process proceeds to step S58 to connect to the positive terminal of the battery cell on the highest potential side among the battery cells constituting the high voltage battery. The p-side switching element SpdN thus turned on and the n-side switching element Snd1 connected to the negative electrode terminal of the battery cell on the lowest potential side are turned on.

  In the subsequent step S60, the process waits until the fifth specified time T5 elapses after the turning-on operation of the switching elements SpdN and Snd1 is started by the process in step S58. Here, the fifth specified time T5 is set to a time when it is assumed that the charging of the capacitor 40 is completed by the electric energy of the high voltage battery. Specifically, the fifth specified time T5 can be set by a method similar to the method described in the process of step S20 of FIG.

  In the subsequent step S62, the switching elements SpdN and Snd1 that are turned on in the process of step S58 are turned off. Thereafter, the process proceeds to step S52.

  On the other hand, if a negative determination is made in step S46, it is determined that the equalization of the voltage across the terminals of the first battery 10 and the second battery 20 has been completed, and the value of the determination flag F is set to “0”. Proceed to step S64. In step S64, charging voltage gradual reduction processing is performed. This process is a process of gradually decreasing the number of battery cells that constitute the low-voltage battery with respect to the capacitor 40 after the battery voltage equalization process is completed. This process is a process for avoiding an excessive current flowing in the closed circuit including the capacitor 40 when the voltage across the terminals of the capacitor 40 is reduced in preparation for the cell voltage equalization process to be executed later.

  That is, when the voltage of the capacitor 40 is decreased, for example, when the switching elements Spc1 and Snc1 connected to the positive terminal and the negative terminal of the battery cell on the lowest potential side among the battery cells constituting the low voltage battery are turned on, Since the difference between the voltage between the terminals of the battery cell and the voltage between the terminals of the capacitor 40 is large, there is a concern that a large current flows in the closed circuit including the battery cell, the switching element, and the capacitor 40. In order to avoid this, charging voltage gradual reduction processing is performed.

  FIG. 6 shows the procedure of the charging voltage gradual decrease process. This process is repeatedly executed by the control circuit 38 at a predetermined cycle, for example. In this embodiment, this process constitutes “gradual reduction means”.

  In this series of processes, first, in step S200, the n-side switching element Snc1 connected to the negative terminal of the low-voltage battery is turned on.

  In the subsequent step S202, the parameter k is set to “N”. In step S204, it is determined whether or not the parameter k is “1”.

  If a negative determination is made in step S204, the process proceeds to step S206, and the p-side switching element Spck connected to the positive terminal of the kth battery cell from the lowest potential side among the battery cells constituting the low voltage battery is turned off. After that, in step S208, the p-side switching element Spc (k-1) connected to the positive terminal of the "k-1" th battery cell from the lowest potential side is turned on.

  In the subsequent step S210, the process waits until the sixth specified time T6 elapses after the on-operation of the p-side switching element Spc (k-1) is started by the process in step S208. Here, the sixth specified time T6 is the interval between terminals of the series connection body of the “k−1” battery cells from the lowest potential side among the battery cells constituting the low voltage battery. It is set to the time when it is assumed that the voltage has dropped.

  In the subsequent step S212, the parameter k is decremented by 1, and the process returns to step S204.

  If an affirmative determination is made in step S204, the process proceeds to step S214, and the p-side switching element Spc1 connected to the positive terminal of the battery cell on the lowest potential side among the battery cells constituting the low-voltage battery, and the lowest The n-side switching element Snc1 connected to the negative terminal of the potential-side battery cell is turned off.

  In addition, when the process of step S214 is completed, this series of processes is once complete | finished.

  Returning to the description of FIG. 4, in the subsequent step S66, the second to fourth relays R2 to R4 are turned on. Thus, the first relay R1 is turned off and the second to fourth relays R2 to R4 are turned on, and the first connection point TL1 and the second connection point TL2 are used as a pair of terminals. The connection state of the battery 10 and the second battery 20 is switched to the parallel connection. In the present embodiment, the process of this step and step S44 constitutes a “second operating means”.

  In the subsequent step S68, the main relay SMR is turned on.

  If a negative determination is made in step S40, or if the process of step S68 is completed, this series of processes is temporarily terminated.

  Incidentally, in the present embodiment, the processes in steps S46 to S48 and S52 to S62 are performed by switching the p-side switching element Spij and the n-side switching element Snij from the high voltage battery to the low voltage battery via the capacitor 40. Thus, the “assembled battery equalizing means” is configured to move the electric charge and thereby equalize the voltage between the terminals of the first battery 10 and the second battery 20.

  Next, FIG. 7 and FIG. 8 show an example of the battery voltage equalization processing according to the present embodiment. Here, FIG. 7 shows the transition of the voltage Vc between the terminals of the capacitor 40 when the battery voltage equalization process or the like is performed, and FIG. 8 shows the first battery 10 when the battery voltage equalization process is performed. The transition of the inter-terminal voltage V1 and the inter-terminal voltage V2 of the second battery 20 is shown. 7 and 8, the high voltage battery is the first battery 10 and the low voltage battery is the second battery 20.

  As shown in FIG. 7, the charging voltage gradual increase process is started at time t1 prior to the battery voltage equalization process. As a result, the terminal voltage Vc of the capacitor 40 gradually increases, and then the terminal voltage Vc of the capacitor 40 increases to the terminal voltage V1 of the first battery 10 at time t2.

  Then, at time t2, the battery voltage equalization process is started. Thereafter, at time t3 when it is determined that the absolute value of the difference ΔV between the terminal voltage V1 of the first battery 10 and the terminal voltage V2 of the second battery 20 is equal to or lower than the threshold voltage Vth (see FIG. 8), the battery voltage The equalization process is completed, and the charging voltage gradual reduction process is started. Thereby, the inter-terminal voltage Vc of the capacitor 40 gradually decreases, and then at the time t4, the inter-terminal voltage Vc of the capacitor 40 decreases to the inter-terminal voltage C0 of one battery cell constituting the second battery 20.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) Prior to switching the first battery 10 and the second battery 20 to parallel connection, a battery voltage equalization process was performed. For this reason, when the first battery 10 and the second battery 20 are switched to the parallel connection, it is possible to avoid a large current from flowing between the batteries 10 and 20, thereby reducing the reliability of the batteries 10 and 20. Can be avoided.

  Furthermore, in the present embodiment, the charge / discharge circuit that uses the equalization of the voltage between the terminals of the first battery 10 and the second battery 20 in the cell voltage equalization process is used. For this reason, the number of additional components of the power supply device for equalizing the voltage between the terminals of the first battery 10 and the second battery 20 can also be reduced.

  (2) A charging voltage gradual increase process was performed. According to this process, since the number of battery cells constituting the high-voltage battery with respect to the capacitor 40 can be increased one by one, the voltage between the terminals of the capacitor 40 can be gradually increased. Thereby, the voltage between the terminals of the first battery 10 and the second battery 20 can be equalized without causing an excessive current to flow, and as a result, power loss due to equalization can be reduced.

  (3) The charging voltage was gradually reduced. According to this process, when the voltage between the terminals of the capacitor 40 is decreased, the sudden decrease in the number of battery cells connected to the capacitor 40 can be avoided, and the sudden decrease in the voltage between the terminals of the capacitor 40 can be avoided. Thereby, the voltage between the terminals of the capacitor 40 can be reduced without flowing an excessive current.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the first embodiment, the capacitor 40 used in the cell voltage equalization process is shared by the first battery 10 and the second battery 20. In the present embodiment, the capacitors used in the above processing are provided separately for the first battery 10 and the second battery 20.

  FIG. 9 shows a system configuration according to the present embodiment. In FIG. 9, the same members as those shown in FIG. 1 are given the same reference numerals for the sake of convenience.

  As illustrated, in the present embodiment, a first capacitor 40a and a second capacitor 40b are provided as capacitors used in the cell voltage equalization process. Here, the first capacitor 40 a is provided corresponding to the first battery 10, and the second capacitor 40 b is provided corresponding to the second battery 20.

  The fifth relay R5 opens and closes between the connection point of the eleventh p-side switching element Sp11 and the connection point of the second N-side switching element Sp2N in the first electrical path Lα. In addition, the sixth relay R6 opens and closes the connection point between the eleventh n-side switching element Sn11 and the connection point between the second N-th switching element Sn2N in the second electric path Lβ. The fifth relay R5 and the sixth relay R6 are turned on and off by the control circuit 38.

  One end of the first capacitor 40a is connected to the first j-side p-side switching element Sp1j of the first electrical path Lα relative to the fifth relay R5, and the sixth relay of the second electrical path Lβ is connected to the sixth relay. The other end of the first capacitor 40a is connected to the first j-side switching element Sn1j side of R6. In addition, one end of the second capacitor 40b is connected to the second j-side switching element Sp2j side of the first electrical path Lα from the second relay R5, and the sixth electrical path Lβ is connected to the sixth electrical path Lα. The other end of the second capacitor 40b is connected to the second j-side switching element Sn2j side of the relay R6.

  Next, the cell voltage equalization process according to the present embodiment will be described.

  In the present embodiment, cell voltage equalization processing is performed for the first battery 10 using the first capacitor 40a, and cell voltage equalization processing is performed for the second battery 20 using the second capacitor 40b. I do. In this embodiment, the cell voltage equalization process of each of the first battery 10 and the second battery 20 is performed simultaneously by turning off the fifth relay R5 and the sixth relay R6. According to such a configuration, the equalization of the voltage between the terminals of the battery cells constituting each of the batteries 10 and 20 can be quickly completed.

  In the present embodiment, the battery voltage equalization process may be performed, for example, in a situation where the fifth relay R5 and the sixth relay R6 are turned on.

  According to the present embodiment described above, in addition to the effect obtained in the first embodiment, an effect that the cell voltage equalization process can be completed quickly can be obtained.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In this embodiment, when the 1st battery 10 and the 2nd battery 20 are switched to parallel connection, suppression of the ground fault electric current which flows from the negative electrode terminal of the 1st battery 10 to a grounding part is aimed at.

  FIG. 10 shows a system configuration according to the present embodiment. In FIG. 10, the same members as those shown in FIG. 1 are denoted by the same reference numerals for the sake of convenience.

  As illustrated, in the present embodiment, the second electrical path Lβ side of both ends of the capacitor 40 and the grounding part are connected via a switching element 42 as “fifth opening / closing means”. The switching element 42 is turned on and off by the control circuit 38. In the present embodiment, a pair of N-channel MOSFETs whose sources are short-circuited with each other are used as the switching element 42.

  Then, the ground fault current suppression process concerning this embodiment is demonstrated.

  Before the first battery 10 and the second battery 20 are switched to the parallel connection, the first to fourth relays R1 to R4 are turned off (for example, the completion of the process in step S44 of FIG. 4 above). In the latter case, the potential (ground voltage) of the negative terminal of the first battery 10 with respect to the potential of the grounded part may increase. In this case, if the third relay R3 is turned on to switch the first battery 10 and the second battery 20 to the parallel connection, a ground fault current may flow from the negative terminal of the first battery 10 to the grounded portion. There is. In order to deal with such a problem, a ground fault current suppression process is performed. In the present embodiment, this process constitutes a “processing unit”.

  In the present embodiment, as the above process, the switching element 42 is intermittently turned on before the first battery 10 and the second battery 20 are switched to the parallel connection (for example, after completion of step S44 in FIG. 4). Perform the process.

  FIG. 11 shows a ground fault current suppression process according to the present embodiment. Here, FIG. 11A shows the transition of the operation state of the eleventh n-side switching element Sn11, and FIG. 11B shows the transition of the operation state of the switching element 42.

  Prior to switching to parallel connection, the eleventh n-side switching element Sn11 is turned on and the switching element 42 is turned on intermittently at times t1 to t2, as shown in the figure. According to the intermittent ON operation of the switching element 42, it is possible to reduce the ground voltage of the negative terminal while reducing the current flowing from the negative terminal side of the first battery 10 to the grounded part via the switching element 42. it can. For this reason, it can suppress that a ground fault current flows when the 1st battery 10 and the 2nd battery 20 are switched to parallel connection after that in time t3.

  The time during which the switching element 42 is intermittently turned on may be a fixed time or may be a time until it is determined that the ground voltage detected by the control circuit 38 has become less than a predetermined value. When the switching element 42 is intermittently turned on, the gate voltage of the switching element 42 is a MOSFET in a non-saturated region where the drain current increases as the voltage between the drain and the source of the MOSFET constituting the switching element 42 increases. Is set to drive the voltage. That is, the on-resistance of this element when the switching element 42 is turned on is substantially zero.

  Incidentally, in the present embodiment, the battery voltage equalization process is performed after the switching element 42 is returned to the OFF operation.

  According to the present embodiment described above, in addition to the effects obtained in the first embodiment, a ground fault current flows when the first battery 10 and the second battery 20 are switched to parallel connection. The effect that can be suppressed can be obtained.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, the power supply device is applied to a hybrid vehicle including a rotating machine and an internal combustion engine as an in-vehicle main machine.

  FIG. 12 shows a system configuration according to the present embodiment. In FIG. 12, the same members as those shown in FIG. 1 are given the same reference numerals for the sake of convenience. In the present embodiment, the main relay SMR is referred to as a first main relay SMR1.

  As shown in the figure, in the present embodiment, an engine 43 is provided as an in-vehicle main machine in addition to the motor generator 34. The rotor of the motor generator 34 and the crankshaft of the engine 43 are connected to the drive wheels 36 via the power split mechanism 44.

  In the present embodiment, in addition to the first battery 10 and the second battery 20, a main storage battery (hereinafter referred to as a main battery 46) different from these batteries 10 and 20 is provided as a power source for the motor generator 34. . In the present embodiment, the main battery 46 is basically used as a power source for the motor generator 34, and the first battery 10 and the second battery 20 are provided for the purpose of increasing the cruising distance of the vehicle. The main battery 46 may be, for example, a lithium ion secondary battery or a nickel hydride secondary battery.

  Main battery 46 is connected to motor generator 34 via boost converter 50 and inverter 32. Here, boost converter 50 includes smoothing capacitor 30, a pair of switching elements Scp and Scn (IGBT) connected in parallel to smoothing capacitor 30, and a connection point between the pair of switching elements Scp and Scn and a positive terminal of main battery 46. And a reactor 52 are provided. Specifically, the boost converter 50 has a function of boosting the output voltage (for example, “288V”) of the main battery 46 up to a predetermined voltage (for example, “666V”) by turning on / off the switching elements Scp, Scn. The output voltage of boost converter 50 (voltage between terminals of smoothing capacitor 30) is detected by voltage sensor 54. The detection value of the voltage sensor 54 is input to the control circuit 38.

  Note that free wheel diodes Dcp and Dcn are connected in antiparallel to the switching elements Scp and Scn, respectively. Further, the main battery 46 and the boost converter 50 are opened and closed by the second main relay SMR2. The second main relay SMR2 is turned on, for example, when a user of the vehicle turns on an ignition switch.

  Incidentally, in this embodiment, the switching elements Scp and Scn and the second main relay SMR2 are turned on and off by the control circuit 38. However, the present invention is not limited to this, and the switching elements Scp and Scn and the second main relay SMR2 may be operated by a control circuit different from the control circuit 38.

  Next, the output voltage adjustment process will be described with reference to FIG. Here, FIG. 13 is a flowchart showing the procedure of the vehicle control process including the output voltage adjustment process. The above processing is repeatedly executed by the control circuit 38 at a predetermined cycle, for example.

  In this series of processes, first, in step S70, it is determined whether or not the vehicle is to be traveled only by the motor generator 34 (hereinafter referred to as EV travel).

  If a negative determination is made in step S70, it is determined that both the motor generator 34 and the engine 43 are to be traveled using the travel power source (hereinafter referred to as HV travel), and the process proceeds to step S72. In step S72, the first main relay SMR1 is turned off so that the motor generator 34 is powered only by the main battery 46.

  On the other hand, when an affirmative determination is made in step S70, it is determined that the EV travel is performed, and the process proceeds to step S74. In step S74, the first main relay SMR1 is turned on so that the motor generator 34 is powered by the main battery 46, the first battery 10, and the second battery 20.

  In the subsequent step S76, the output voltage adjustment process is performed. In this process, the absolute value of the difference between the output voltage Vs of the first battery 10 and the second battery 20 connected in series or in parallel and the output voltage Vm of the boost converter 50 detected by the voltage sensor 54 is predetermined. This is a process for operating the boost converter 50 so as to be equal to or less than the value γ. In this process, the difference between the output voltage of the boost converter 50 and the output voltages of the first battery 10 and the second battery 20 is increased, so that the first battery 10 and the second battery 20 and the main battery 46 are increased. Is a process for avoiding a current from flowing from one to the other. In this embodiment, the process of this step constitutes “voltage operating means”.

  In addition, when the process of step S72, S76 is completed, this series of processes is once complete | finished.

  By the way, according to the present embodiment in which the main battery 46 is provided, the first main relay SMR1 is temporarily turned off when the first battery 10 and the second battery 20 are switched to the serial connection or the parallel connection. However, the motor generator 34 can be driven by using the main battery 46 as a power source to drive the vehicle.

  According to this embodiment described above, in addition to the effects obtained in the first embodiment, the following effects can be obtained.

  (4) An output voltage adjustment process was performed. For this reason, it is possible to avoid a current from flowing from one of the first battery 10 and the second battery 20 and the main battery 46 during EV travel.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  -"Switching means" is not restricted to what changes the connection state of a some assembled battery in order to connect all the some assembled batteries with which an electric power supply system is equipped in series connection or parallel connection. For example, in a power supply system provided with three or more assembled batteries, the connection state of the plurality of assembled batteries is switched to be a part of the plurality of assembled batteries and to connect two or more in series or in parallel. There may be.

  -"Unit battery selection means" is not restricted to what was illustrated to the said 1st Embodiment. For example, a unit battery higher than the average voltage of a plurality of unit batteries may be selected as the unit battery of the power supply source, and a unit battery lower than the average voltage may be selected as the unit battery of the power supply destination. .

  Further, the numbers of the power supply source and the power supply destination selected by the “unit battery selection unit” may be variably set without being fixed. Specifically, for example, the larger the charging current to the power supply destination unit battery in one cycle of the pair of charging and discharging processes, the more the number of power supply unit cells and the power supply unit battery. What is necessary is just to variably set the number of these unit batteries so that the absolute value of the difference of the numbers becomes large.

  The number of power supply source unit batteries selected by the “unit battery selection unit” is not limited to three, but may be other than that. Further, the number of unit batteries as power supply destinations is not limited to one and may be plural. Further, the number of unit batteries as power supply destinations may be larger than the number of unit batteries as power supply sources.

  -The application of the "charge / discharge circuit" is not limited to equalization of the voltage between terminals of battery cells constituting an assembled battery. For example, when the temperature of an assembled battery is low, you may use for the use which raises the temperature of an assembled battery by repeating charging / discharging process between battery cells or between modules. In this case, the larger the charge / discharge current, the greater the amount of heat generated by the internal resistance of the battery cell, and the higher the rate of temperature rise. For this reason, as the temperature of the assembled battery is lower, the number of power supply source battery cells may be increased, or the number of power supply destination battery cells may be decreased.

  In addition, the application of the “charge / discharge circuit” is not limited to the transfer of electric charge from the unit battery of the power supply source to the unit battery of the power supply destination via the power storage unit. For example, a process of opening and closing the p-side and n-side switching elements Spij and Snij so that an AC voltage is applied to the power storage means may be performed. According to this process, the DC voltage of the assembled battery can be converted into an AC voltage, and the converted AC voltage can be output to the outside via the storage means.

  The “assembled battery equalizing means” is not limited to that exemplified in the first embodiment. For example, in a power supply system including three or more assembled batteries, the battery voltage having the highest voltage between terminals as a high-voltage battery and the battery voltage having the lowest voltage between terminals as a low-voltage battery among these assembled batteries. An equalization process may be performed. Here, it is determined that the difference between the voltage between the terminals of the high-voltage battery and the voltage between the terminals of the low-voltage battery among the three or more assembled batteries is equal to or lower than the threshold voltage Vth. It may be determined that the equalization is completed.

  As the “charge / discharge circuit”, a p-side switching element Spij is connected to each positive electrode terminal of the plurality of battery cells Cij constituting the battery, and an n-side switching element is connected to each negative electrode terminal of the plurality of battery cells Cij. It is not restricted to what Snij is connected to. For example, as shown in FIG. 2 of Japanese Patent Application No. 2012-231554, a charge / discharge circuit that aims to reduce the number of p-side switching elements spij and n-side switching elements Snij may be used.

  The “processing unit” is not limited to that exemplified in the third embodiment. For example, prior to switching to parallel connection, a process of increasing the resistance value of the switching element 42 while turning on the switching element 42 may be performed. This can be realized by setting the gate voltage of the switching element 42 to a voltage that drives the switching element 42 in the saturation region. Here, the saturation region is a region where the drain current is constant regardless of the magnitude of the drain-source voltage of the MOSFET constituting the switching element 42.

  Further, the “processing means” is not limited to the one that performs the ground fault current suppression process every time switching to parallel connection. For example, prior to switching the first battery 10 and the second battery 20 to parallel connection, the potential difference between the negative terminal of the first battery 10 and the negative terminal of the second battery 20 is detected by the control circuit 38 and detected. The ground fault current suppression process may be performed only when it is determined that the potential difference (ground voltage) is greater than or equal to a predetermined value.

  In the third embodiment, the negative terminal of the first battery 10 may be connected to the ground part. In this case, for example, the negative electrode terminal of the second battery 20 may be connected to the ground portion via the twenty-first n-side switching element Sn21 and the switching element 42.

  Further, in the third embodiment, when three or more battery packs are provided, each of the negative battery terminals and grounding parts of the battery packs other than the battery pack in which the negative electrode terminal is connected to the grounding part among the plurality of battery packs. What is necessary is just to employ | adopt the structure which opens and closes between these by the switching element for earth fault current suppression.

  In the fourth embodiment, only the sub battery may be used during EV travel. In this case, the output voltage adjustment process is not necessary.

  The “power storage means” is not limited to a capacitor, and may be other means as long as it has a similar function.

  The “assembled battery” is not limited to a secondary battery such as lithium ion, but may be a fuel cell, for example.

  DESCRIPTION OF SYMBOLS 10 ... 1st battery, 20 ... 2nd battery, 40 ... Capacitor, Cij ... Battery cell, Spij ... P side switching element, Snij ... N side switching element, L (alpha) ... 1st electric path | route, L (beta) ... 2nd Electrical path, R1 to R4: first to fourth relays.

Claims (10)

Applied to a power supply system including a plurality of assembled batteries (10, 20) as a series connection body of unit batteries (Cij; i = 1, 2: j = 1 to N) which are one or a plurality of adjacent battery cells. And
A charge / discharge circuit (Spij, Snij, Lα, Lβ) that has electric storage means (40, 40a, 40b) for storing electric energy and moves electric charge between the electric storage means and the unit cell;
Switching means (R1 to R4) for switching the connection state of the plurality of assembled batteries in order to connect at least two of the plurality of assembled batteries in series or in parallel;
Prior to switching the assembled battery to parallel connection by the switching means, an assembled battery equalizing means for equalizing the voltage between the terminals of the assembled batteries switched to the parallel connection via the power storage means;
Equipped with a,
The charge / discharge circuit is
A first electrical path (Lα) connected to one end of the power storage means;
A second electrical path (Lβ) connected to the other end of the power storage means;
Positive-side opening / closing means (Spij) for opening / closing between each positive electrode terminal of the unit battery constituting the assembled battery and the first electric path;
Negative electrode side opening / closing means (Snij) for opening and closing between each negative electrode terminal of the unit battery constituting the assembled battery and the second electric path;
Have
Prior to starting equalization by the assembled battery equalizing means, the number of connections of the unit cells constituting the assembled battery that charges the power storage means among the assembled batteries switched to the parallel connection to the power storage means power supply, characterized in Rukoto includes an incremental unit for increasing by opening and closing the positive electrode side switching means and the negative electrode side switching means corresponding to the assembled battery to charge the unit. The battery pack further comprises an assembled battery selection means for selecting an assembled battery with the highest voltage between terminals and an assembled battery with the lowest voltage between terminals from the assembled batteries to be switched to the parallel connection,
The assembled battery equalizing means moves the electric charge from the highest assembled battery to the lowest assembled battery via the power storage means by opening and closing the positive electrode side opening / closing means and the negative electrode side opening / closing means. The power supply device according to claim 1, wherein a voltage between terminals of the assembled batteries switched to the parallel connection is equalized. The gradual increase means opens and closes the number of connections of the unit battery constituting the highest assembled battery to the power storage means by opening and closing the positive side opening / closing means and the negative side opening / closing means corresponding to the highest assembled battery. power supply device according to claim 2, wherein the benzalkonium is gradually increased.   4. The method according to claim 2, further comprising a gradual decrease means for gradually decreasing the number of connections of the unit cells constituting the lowest assembled battery to the power storage means after the completion of equalization by the assembled battery equalization means. Power supply equipment. For each of the plurality of battery packs, the battery pack further comprises unit battery selection means for selecting a power supply source unit battery and a power supply destination unit battery from among the plurality of unit batteries constituting the battery pack.
2. The charge / discharge circuit moves electric charge from the power supply source unit battery selected by the unit battery selection means to the power supply destination unit battery via the power storage means. The power supply apparatus of any one of -4.   The charge / discharge circuit moves terminals from the unit battery of the power supply source to the unit battery of the power supply destination via the power storage unit, thereby the terminals of the plurality of unit cells constituting the assembled battery. 6. The power supply apparatus according to claim 5, wherein the inter-voltage is equalized.   The power supply apparatus according to claim 6, wherein the power storage unit is individually provided for each of the plurality of assembled batteries. In the case where a plurality of the assembled batteries are connected in series, the positive terminal of the assembled battery (10) on the highest potential side among the plurality of assembled batteries is connected to the first connection point (TL1), and the highest potential is obtained. The negative electrode terminal of the assembled battery on the side is connected to the second connection point (TL2),
The switching means is
In the case where a plurality of the assembled batteries are connected in series, a first opening / closing means (R1) that opens and closes between a negative electrode terminal and a positive electrode terminal of the assembled battery that forms an adjacent pair;
In the case where a plurality of the assembled batteries are connected in series, among the plurality of assembled batteries, a first one that opens and closes between the positive terminal of the assembled battery (20) other than the assembled battery on the highest potential side and the first connection point. Two open / close means (R2);
In the case where a plurality of the assembled batteries are connected in series, a third opening / closing means for opening / closing between the negative connection terminal of the assembled battery (20) on the lowest potential side and the second connection point among the plurality of assembled batteries. (R3),
In the case where a plurality of the assembled batteries are connected in series, a first one that opens and closes between the negative connection terminal of the assembled battery (10) other than the assembled battery on the lowest potential side among the plurality of assembled batteries and the second connection point. 4 open / close means (R4);
The first opening and closing means and the third opening and closing means are closed to switch the connection state of the plurality of assembled batteries to series connection using the first connection point and the second connection point as a pair of terminals. First operating means for opening the second opening and closing means and the fourth opening and closing means;
The first opening / closing means is opened to switch the connection state of the plurality of assembled batteries to parallel connection using the first connection point and the second connection point as a pair of terminals, and the second connection point An opening / closing means, a second operating means for closing the third opening / closing means and the fourth opening / closing means;
The power supply device according to any one of claims 1 to 7 , further comprising: The negative terminal of any one (20) of the plurality of the assembled batteries is connected to the ground part,
A fifth opening / closing means (42) for opening / closing between the negative electrode terminal of the assembled battery (10) other than the assembled battery whose negative electrode terminal is connected to the grounded part and the grounded part among the plurality of assembled batteries;
Prior to switching to parallel connection by the switching means, the process of intermittently closing the fifth opening / closing means, or increasing the resistance value of the fifth opening / closing means while closing the fifth opening / closing means Processing means for performing processing;
The power supply device according to claim 8 , further comprising: Applied to vehicles equipped with a rotating machine (34) as an in-vehicle main machine,
The plurality of assembled batteries are power sources for the in-vehicle main unit,
The vehicle is
A main storage battery (46) which is a storage battery separate from the plurality of the assembled batteries and serves as a power source for the in-vehicle main unit;
A boost converter (50) that boosts the output voltage of the main storage battery and outputs the boosted voltage to the rotating machine;
Further comprising
It further comprises voltage operation means for operating the boost converter so that the absolute value of the difference between the output voltage of the battery pack connected in series or in parallel and the output voltage of the boost converter is equal to or less than a predetermined value. The power supply device according to any one of claims 1 to 9 .

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