JP2011155718A - Charging/discharging device - Google Patents

Abstract

To optimize the charge amount of each of a plurality of single cells with high efficiency.
In a control unit 24 of a charge / discharge adjustment unit 20, for each of a plurality of unit cells 2, it is determined whether the unit cell is charged, discharged, or not both charged and discharged. Information of the determination result is transmitted to each of the plurality of charge / discharge management units 30. And the control part 33 of the some charging / discharging management unit 30 carries out on-off control of each switching part 23 based on the information of the received determination result, respectively.
[Selection] Figure 1

Description

  The present invention relates to a charging / discharging device that charges and discharges each of a plurality of unit cells via a transformer, and more particularly to a method for optimizing the charge amount of each unit cell.

  For example, Patent Document 1 discloses an apparatus for equalizing output voltages of a plurality of cells connected in series. This apparatus includes a plurality of first closed circuits and a second closed circuit. I have. Specifically, each first closed circuit includes any one of a plurality of single cells connected in series, one of a plurality of secondary windings magnetically coupled to each other, and a switching element. Is done. The second closed circuit is composed of a unit cell different from the plurality of unit cells, a secondary winding that is magnetically coupled to the plurality of secondary windings, and a switching element. . Then, the output voltages of the plurality of single cells connected in series are equalized by alternately turning on and off each of the switching elements in the plurality of first closed circuits and the switching elements in the second closed circuit.

JP 2002-223528 A

  However, in the method disclosed in Patent Document 1, since all the switching elements on the secondary winding side are collectively turned on / off, switching connected to a single cell that does not require equalization of output voltage is performed. There is an inconvenience that even an element is controlled on and off. For this reason, there is a problem that the power transfer efficiency is poor because of a large switch power loss.

  The present invention has been made in view of such circumstances, and an object of the present invention is to optimize the charge amount of each of the plurality of single cells with high efficiency.

  This invention is a charging / discharging apparatus which charges / discharges each of several cell through a transformer for solving this subject. This charging / discharging device is provided for each unit cell, each of which includes a plurality of switching means interposed between the unit cell and the transformer winding, and a plurality of charging / discharging control units for each of the plurality of switching units. Discharge management means and charge / discharge adjustment means for judging whether to charge, discharge, or not charge / discharge each of the plurality of unit cells, with each of the unit cells being determined. In this case, the charge / discharge adjustment unit transmits a determination result to each of the plurality of charge / discharge management units, and the plurality of charge / discharge management units turn on / off each individual switching unit based on the received determination result. Control.

  The present invention may further include a power source and main switching means interposed between the power source and the transformer winding. In this case, it is preferable that the charging / discharging adjusting unit controls on / off of the main switching unit and transmits the determination result to each charging / discharging managing unit via the transformer.

  In the present invention, the charge / discharge adjustment means transmits the determination result to each charge / discharge management means via the transformer by performing on / off control of the main switching means at a frequency higher than the switching frequency at the time of charging / discharging the power. It is desirable.

  Further, in the present invention, it is preferable that the charge / discharge adjustment unit controls on / off of the main switching unit and transmits an address signal indicating the location of the unit cell and a determination result signal indicating the determination result. Here, the determination result signal can include a charge / discharge signal indicating whether charging / discharging is performed or charging / discharging, and a charge / discharge amount signal indicating the charge / discharge amount. Note that the determination result signal may further include a charge amount signal indicating a target state of charge (SOC).

  Further, in the present invention, when the plurality of charge / discharge management means receives the address signal and the determination result signal, each of the switching means is controlled to turn on / off, and the received address signal and the determination result signal are returned to the charge / discharge adjustment means. It is preferable.

  According to the present invention, since individual switching means can be controlled independently, it is possible to selectively control the switching means corresponding to any single cell that needs to exchange power. Therefore, it is possible to minimize the number of switching means that are operated in accordance with power transfer. As a result, power loss associated with the switching operation can be reduced, and the optimization operation can be performed with high efficiency.

The schematic diagram which shows the structure of the hybrid vehicle to which the charging / discharging apparatus 10 concerning 1st Embodiment was applied. Explanatory drawing which shows the structure of the charging / discharging adjustment unit 20 typically. Explanatory drawing which shows the structure of the charge / discharge management unit 30 typically. Explanatory drawing explaining operation | movement of the charging / discharging apparatus 10 concerning 1st Embodiment. Illustration of communication frames FM, FS Explanatory drawing explaining operation | movement of the charging / discharging apparatus 10 concerning 1st Embodiment. Explanatory drawing explaining the operation | movement as a modification of the charging / discharging apparatus 10 of 1st Embodiment. The schematic diagram which shows the principal part of the structure of the charging / discharging apparatus 10 concerning 2nd Embodiment. The schematic diagram which shows the structure as a modification of the charging / discharging apparatus 10 concerning 2nd Embodiment.

(First embodiment)
FIG. 1 is a schematic diagram illustrating a configuration of a hybrid vehicle to which the charge / discharge device 10 according to the first embodiment is applied. In this hybrid vehicle, the electric power from the assembled battery 1 functioning as a battery is voltage-converted by the DC / DC converter 3 and then output to the inverter 4, and the inverter 4 receives the DC power supplied from the DC / DC converter 3. Is converted into three-phase AC power and output to the motor 5. Further, the three-phase AC power generated by the generator 6 driven by the power of an engine (not shown) or the three-phase AC power generated by the regenerative operation of the motor 3 is converted into DC power by the inverter 4, This direct-current power is voltage-converted by the DC / DC converter 3 and then charged to the assembled battery 1. A charging circuit 7 is provided between the DC / DC converter 3 and the assembled battery 1, and the charging circuit 7 controls the upper limit charging voltage so that the individual cells 2 are not overcharged. Or, control is performed so that the current supplied to the assembled battery 1 does not exceed a certain level.

  Here, the assembled battery 1 is configured by connecting a plurality of unit cells 2 in series. As each unit cell 2, for example, a lithium ion battery can be used. In the present embodiment, the cell 2 is composed of a single battery element, but may be composed of a plurality of battery elements connected in parallel or in series with each other.

  The charging / discharging device 10 according to the present embodiment is a device that charges and discharges each of a plurality of batteries via a transformer. In the present embodiment, the assembled battery 1 is configured for the assembled battery 1 as a battery. The charging / discharging regarding the some cell 2 to control is controlled. Specifically, the charging / discharging device 10 is used between any single cells 2 in a non-charging operation except for a charging operation in which the power generated by the generator 6 or the regenerative power generated by the motor 5 is charged to the assembled battery 1. By transferring power, the state of charge (SOC) of each unit cell 2 is adjusted, and thereby the amount of charge of each unit cell 2 is optimized.

  The charging / discharging device 10 is mainly configured by a charging / discharging adjustment unit 20, a plurality of charging / discharging management units 30, and a transformer 40. The plurality of charge / discharge adjustment units 20 are provided corresponding to the individual single cells 2 so as to have a one-to-one relationship with the single cells 2 constituting the assembled battery 1. A plurality of windings 41 corresponding to each charge / discharge management unit 30 and a winding 42 corresponding to the charge / discharge adjustment unit 20 are wound around a common magnetic core of the transformer 40.

  Here, the windings 41 of the individual charge / discharge management units 30 are wound to have the same polarity (winding direction), and the windings 41 are magnetically coupled to each other. The winding 42 of the charge / discharge adjustment unit 20 is wound so as to have the same polarity as the winding 41 of each charge / discharge management unit 30 and is magnetically coupled to each winding 41. Each winding 41 functions as a primary winding when power is output from the unit cell 2 connected to itself to another unit cell 2 or the power source 21, and is connected to the other unit cell 2 or the power source 21 to itself. It also functions as a secondary winding when power is input to the unit cell 2 to be operated. On the other hand, the winding 42 functions as a primary winding when power is output from the power source 21 to the single battery 2, and also functions as a secondary winding when power is input from the single battery 2 to the power source 21. The windings 41 and 42 also have a function as a communication path for transmitting a signal between the charge / discharge adjustment unit 20 and each charge / discharge management unit 30.

  FIG. 2 is an explanatory diagram schematically showing the configuration of the charge / discharge adjustment unit 20. The charge / discharge adjustment unit 20 comprehensively controls the operation of each charge / discharge management unit 30. Specifically, the charge / discharge adjustment unit 20 transmits a signal to / from each charge / discharge management unit 30 via the transformer 40, so that the state of the unit cell 2 associated with each charge / discharge management unit 30 is determined. , And the charge / discharge management unit 30 is controlled based on the result of acquisition to optimize the charge amount of each unit cell 2.

  Further, the charge / discharge adjustment unit 20 transmits and receives power via the transformer 40 as necessary. Thereby, the charging / discharging adjustment unit 20 charges the power from one of the single cells 2 to the power source 21, or outputs the power charged in the power source 21 as the charging power in one of the single cells 2. can do.

  The charge / discharge adjustment unit 20 includes a power source 21, a switching unit (main switching unit) 23, a control unit (charge / discharge adjustment unit) 24, and a voltage detection unit 25.

  The power source 21 is a DC power source and is a rechargeable secondary battery. The power source 21 can charge the power discharged from any one of the cells 2 or can discharge the power charged by itself as charging power for any of the cells 2. As the power source 21, for example, a low-voltage battery (for example, a 12V lead storage battery) mounted on a hybrid vehicle can be used. A power line is connected to both the positive and negative terminals of the power source 21, and the power source 21 and the winding 42 are connected to each other via a pair of power lines.

  A capacitor C for smoothing the power supply voltage of the power source 21 is provided between the positive power line and the negative power line, and each power line is for removing high frequency noise. An inductor L is provided.

  The switching unit 23 is provided in a power line between the power source 21 and the winding 42, and switches the conduction state by opening and closing the power line (on / off operation). The switching unit 23 includes a bridge circuit including four transistors Tr1 to Tr4 (for example, FET: Field effect transistor). In this bridge circuit, the positive side of the power source 21 is connected between the transistors Tr1 and Tr2, and the negative side of the power source 21 is connected between the transistors Tr3 and Tr4. One terminal side of the winding 42 is connected between the transistors Tr1 and Tr3, and the other terminal side of the winding 42 is connected between the transistors Tr2 and Tr4. Further, body diodes D1 to D4 are connected in antiparallel to each of the transistors Tr1 to Tr4. Each of the transistors Tr1 to Tr4 is connected to the control unit 24, and is controlled to be turned on / off by a signal from the control unit 24.

  The control unit 24 controls the switching unit 23 to communicate with each of the charge / discharge management units 30 and to exchange power with an arbitrary unit cell 2 as necessary. As the control unit 24, a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used. The control unit 24 operates with power supplied from the power source 21.

  A detection signal detected by the voltage detection unit 25 is input to the control unit 24. The voltage detection unit 25 is a comparator with hysteresis, for example, and is connected in parallel to the winding 42. The voltage detection unit 25 outputs a detection signal (pulse signal) corresponding to the winding voltage when the output voltage changes according to the winding voltage appearing in the winding 42. The detection signal output from the voltage detection unit 25 is branched into two systems and then input to the control unit 24. A detection signal passing through one system is input to the control unit 24 as it is, and a detection signal passing through the other system is input to the control unit 24 after passing through the filter circuit 26. The filter circuit 26 has a function as a high-pass filter, and allows a signal having a frequency component equal to or higher than a predetermined frequency among detection signals output from the voltage detection unit 25 to pass therethrough. The filter circuit 26 may be a band pass filter, and the signal may be modulated.

  When this is functionally grasped, the control unit 24 includes a reception unit 24a, a phase detection unit 24b, a charge / discharge adjustment unit 24c, a transmission unit 24d, and a switch control unit 24e.

  The receiving unit 24a receives the high-frequency component detection signal that has passed through the filter circuit 26, and outputs the reception result to the charge / discharge adjusting unit 24c. As will be described later, among the detection signals output from the voltage detection unit 25, the detection signal corresponding to the high frequency component corresponds to a signal transmitted from the charge / discharge management unit 30 side.

  The phase detection unit 24b detects the rise or fall of the voltage of the detection signal based on the detection signal output from the voltage detection unit 25, and outputs the detection result to the charge / discharge adjustment unit 24c.

  The charge / discharge adjustment unit 24 c grasps the state of the unit cell 2 detected by each charge / discharge management unit 30 based on the reception result output from the reception unit 24 a, that is, the signal from the charge / discharge management unit 30. To do. Then, the charge / discharge adjustment unit 24c determines whether each unit cell 2 is to be determined, whether the unit cell 2 is charged, discharged, or not both charged and discharged. This determination is made in consideration of the states of all the unit cells 2 constituting the assembled battery 1 from the viewpoint of optimizing the charge amount of each unit cell 2. For example, in this optimization, the charge amount of all the unit cells 2 is equalized, or a plurality of unit cells 2 are classified according to their capacities, and each unit cell belonging to the group is classified for each classified group. The charge amount of 2 is made uniform.

  The charge / discharge adjustment unit 24c also determines the charge amount for the unit cell 2 to be charged, and also determines the discharge amount for the unit cell 2 to be discharged. This charge / discharge amount is a parameter indicating an increase / decrease amount of the charge amount based on the current charge amount (SOC) of the unit cell 2 to be charged / discharged, and the target of the unit cell 2 to be charged / discharged Various indirect parameters capable of defining the charge / discharge amount, such as the amount of charge (SOC), or a combination of these may be included. The charge / discharge adjustment unit 24c basically performs power transfer between the single cells 2, that is, between the single cell 2 to be charged and the single cell 2 to be discharged. The charge / discharge amount is determined as follows. The unit cell 2 to be charged and the unit cell 2 to be discharged are not only in a one-to-one relationship, but may have a one-to-many or many-to-many relationship. In this case, the total discharge amount and the charge amount are Set to correspond. Then, the charge / discharge adjustment unit 24c transmits the determination result to each of the plurality of charge / discharge management units 30 via the transmission unit 24d.

  In addition, the charge / discharge adjustment unit 24c controls the switching unit 23 via the switch control unit 24e according to the detection result of the phase detection unit 24b, thereby charging the power source 21 with the power from the unit cell 2, The power stored in the power source 21 is output to the unit cell 2. As a result, when the voltage difference between the single cells 2 to be charged / discharged is small and it is inappropriate or inefficient to transfer power between the single cells 2 due to a winding error, the power between the single cells 2 When the exchange is performed via the power source 21 or when the charge amount or discharge amount on the unit cell 2 side is uneven, this uneven charge / discharge amount can be efficiently covered with the voltage or power of the power source 21. .

  The transmission unit 24d performs on / off control of the switching unit 23 via the switch control unit 24e based on the transmission information output from the charge / discharge adjustment unit 24c. The transmission unit 24d generates a pulse signal corresponding to transmission information by, for example, PWM-modulating the switching unit 23 via the switch control unit 24e, and thereby generates individual charge / discharge management units 30 via the transformer 40. Various information is transmitted as signals.

  The switch control unit 24e performs on / off control of the switching unit 23 in accordance with an instruction from the charge / discharge adjustment unit 24c or an instruction from the transmission unit 24d. Specifically, the switch control unit 24e controls the transistors Tr1 and Tr4 to turn on, whereby a drain current flows through the transistors Tr1 and Tr4, thereby applying a voltage to the winding 42 (positive phase on control). ). On the other hand, when the transistors Tr1 and Tr4 are turned off, no drain current flows through the transistors Tr1 and Tr4, so that no voltage is applied to the winding 42 (positive phase off control). On the other hand, when the transistors Tr2 and Tr3 are turned on, a drain current flows through the transistors Tr2 and Tr3, thereby applying a reverse polarity voltage to the winding 42 (reverse phase on control). On the other hand, when the transistors Tr2 and Tr3 are turned off, no drain current flows through the transistors Tr2 and Tr3, so that no voltage is applied to the winding 42 (reverse phase off control).

  FIG. 3 is an explanatory diagram schematically showing the configuration of the charge / discharge management unit 30. The charge / discharge management unit 30 detects the state of the unit cell 2 associated with itself, or performs charge / discharge of the unit cell 2 via the transformer 40. The charge / discharge management unit 30 transmits and receives signals to and from the charge / discharge adjustment unit 20 via the transformer 40. Through the transmission / reception of this signal, the charge / discharge management unit 30 notifies the charge / discharge adjustment unit 20 of the detected state of the unit cell 2, or acquires information that is a premise of charge / discharge control from the charge / discharge adjustment unit 20. .

  The charge / discharge management unit 30 includes a switching unit (switching unit) 32, a control unit (charge / discharge management unit) 33, a state detection unit 34, and a voltage detection unit 35. In the charge / discharge management unit 30, power lines are connected to both the positive and negative terminals of the unit cell 2, and the unit cell 2 and the winding 41 are connected to each other via a pair of power lines. In addition, a capacitor C for smoothing the power supply voltage of the unit cell 2 is provided between the positive power line and the negative power line, and each power line is for removing high frequency noise. Inductor L is provided.

  The switching unit 32 is provided in a power line between the unit cell 2 and the winding 41, and switches the conduction state by opening and closing the power line (on / off operation). Similar to the switching unit 23 described above, the switching unit 32 is configured by a bridge circuit including four transistors Tr1 to Tr4 (for example, FET: Field effect transistor). Each of the transistors Tr1 to Tr4 is connected to the control unit 33, and is controlled to be turned on / off by a signal from the control unit 33.

  The control unit 33 controls the switching unit 32 to communicate with the charge / discharge adjustment unit 20 and to exchange power with other unit cells 2 or the power source 21. As the control unit 33, a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used. The control unit 33 operates with electric power supplied from the unit cell 2 associated with itself.

  A detection signal detected by the state detection unit 34 and the voltage detection unit 35 is input to the control unit 33. The state detection unit 34 detects the state of the unit cell 2. The state of the unit cell 2 detected by the state detection unit 34 according to the present embodiment is typically a voltage, but it is also possible to detect current and temperature in addition to this. Similarly to the voltage detection unit 25 of the charge / discharge adjustment unit 20, the voltage detection unit 35 changes the output voltage according to the winding voltage appearing in the winding 41, thereby detecting the detection signal according to the winding voltage change. (Pulse signal) is output. The detection signal output from the voltage detection unit 25 is input to the control unit 33 as it is, and is input to the control unit 33 after passing through the filter circuit 36. The filter circuit 36 has a function as a high-pass filter, and allows a signal having a frequency component equal to or higher than a predetermined frequency among detection signals output from the voltage detection unit 35 to pass therethrough. The filter circuit 36 may be a bandpass filter, and the signal may be modulated.

  The control unit 33 includes a reception unit 33a, a phase detection unit 33b, a charge / discharge control unit 33c, a transmission unit 33d, and a switch control unit 33e when this is functionally grasped. Among these functional elements, the reception unit 33a, the phase detection unit 33b, the transmission unit 33d, and the switch control unit 33e are received among the functional elements constituting the control unit 24 of the charge / discharge adjustment unit 20 described above. The same functions as those of the unit 24a, the phase detection unit 24b, the transmission unit 24d, and the switch control unit 24e are described, and detailed descriptions thereof are omitted.

  The charge / discharge control unit 33c responds to itself by controlling the switching unit 32 via the switch control unit 33e based on the reception result output from the reception unit 33a, that is, the signal from the charge / discharge adjustment unit 20. The charging / discharging of the attached unit cell 2 is controlled. In charge / discharge control, the charge / discharge control unit 33c refers to the detection result output from the phase detection unit 33b as necessary.

  In addition, the charge / discharge control unit 33c transmits the detection result of the state detection unit 34 as a signal to the charge / discharge adjustment unit 20 or receives a signal from the charge / discharge adjustment unit 20 via the transmission unit 33d. Or send a response signal.

  Hereinafter, operation | movement of the charging / discharging apparatus 10 concerning this embodiment is demonstrated. The charge / discharge device 10 optimizes the amount of charge of each unit cell 2 through a communication process performed between the charge / discharge adjustment unit 20 and each charge / discharge management unit 30 and the unit cell 2 performed following this communication process. The charge / discharge process is performed between the two processes, and this operation is repeated with both processes as a set according to the necessity of optimization of the charge amount of each unit cell 2.

  In the description of the operation of the charging / discharging device 10, for convenience, it is assumed that the charge amount needs to be optimized for any two unit cells 2 among the plurality of unit cells 2 constituting the assembled battery 1. The operation related to power transfer between the single cells 2 will be described after the single cell 2 is to be charged and the other single cell 2 is to be discharged. Further, the charge / discharge management unit 30 connected to the unit cell 2 to be charged is referred to as a “charge side charge / discharge management unit 30”, and the charge / discharge management unit 30 connected to the unit cell 2 to be discharged is referred to as “discharge side charge / discharge unit”. It is referred to as “discharge management unit 30”.

  FIG. 4 is an explanatory diagram for explaining the operation of the charge / discharge device 10 according to the present embodiment. In the same figure, (a) is the voltage waveform diagram which combined electric power and a signal. (B) shows the voltage output waveform of the winding 42 provided in the charge / discharge adjustment unit 20, (c) shows the voltage output waveform of the winding 41 provided in the discharge side charge / discharge management unit 30, and (d ) Shows a waveform simulating the gate input voltage of the FET of the switching unit 32 that interfaces with the winding 41 of the charge-side charge / discharge management unit 30.

  A communication process will be described. In this communication process, communication is performed between the charge / discharge adjustment unit 20 and each charge / discharge management unit 30 to grasp the voltage state of each unit cell 2 and charge / discharge connected to the unit cell 2 to be charged / discharged. A charge / discharge instruction is given to the management unit 30. First, a basic communication form between the charge / discharge adjustment unit 20 and the charge / discharge management unit 30 will be described. In this communication process, the switching units 23 and 32 included in the units 20 and 30 are controlled to be in an off state (all of the transistors Tr1 to Tr4 are off) except for a switching operation caused by signal transmission described later.

  First, when the charge / discharge adjustment unit 20 transmits a signal to the charge / discharge management unit 30, the charge / discharge adjustment unit 20 uses a communication frame FM (FM: FM1 to FM3) including various types of information as a charge / discharge management unit. 30. As shown in FIG. 5A, the communication frame FM includes synchronization pattern data, address data, and control signal data. Here, as shown in FIG. 5B, the synchronization pattern data is data for synchronizing the charge / discharge adjustment unit 20 and the charge / discharge management unit 30, for example, the upper 12 bits of the communication frame FM This is the case. The address data is data including address information for identifying the transmission destination and transmission source of the communication frame FM and check bits. For example, 12 bits following the synchronization pattern data of the communication frame FM correspond to this. The control signal data is data including control contents to the charge / discharge management unit 30 and check bits, and corresponds to the lower 18 bits of the communication frame FS.

  In the charge / discharge adjustment unit 20, the charge / discharge adjustment unit 24 c outputs the address of the charge / discharge management unit 30 serving as a transmission destination, its own address as a transmission source, and its control content to the transmission unit 24 d as transmission information. The transmission unit 24d applies a pulse voltage to the winding 42 by performing PWM control of the switching unit 23 via the switch control unit 24e based on the transmission information. Accordingly, the transmission unit 24d transmits the communication frame FM corresponding to the transmission information to each charge / discharge management unit 30 via the transformer 40.

  On the other hand, the charge / discharge management unit 30 receives the communication frame FM transmitted by the charge / discharge adjustment unit 20 via the transformer 40. Specifically, when the communication frame FM is transmitted from the charge / discharge adjustment unit 20, the voltage of the winding 41 appears as a voltage change corresponding to the communication frame FM, and thus this voltage change is detected by the voltage detection unit 35. The The voltage detector 35 outputs a detection signal corresponding to the communication frame FM, which passes through the filter circuit 36 and is received by the receiver 33a. When receiving the detection signal from the voltage detection unit 35, the reception unit 33a extracts each data corresponding to the communication frame FM from the detection signal, and outputs the reception result to the charge / discharge control unit 33c. Based on the reception result, the charge / discharge control unit 33c performs various processes based on the control signal data when the transmission destination of the communication frame FM corresponds to its own address.

  Further, the charge / discharge management unit 30 transmits a communication frame FS (FS: FS1 to FS3) including various information to the charge / discharge adjustment unit 20 in order to send a reply to the charge / discharge adjustment unit 20. As shown in FIG. 5A, the communication frame FS includes address data and control signal data. Here, as shown in FIG. 5C, the address data is data including address information and a check bit for identifying a transmission destination and a transmission source of information, and the upper 12 bits of the communication frame FS correspond to this. . The control signal data is data including a reply content to the charge / discharge adjustment unit 30 and a check bit, and the lower 18 bits of the communication frame FS correspond to this.

  In the charge / discharge management unit 30, the charge / discharge control unit 33c outputs, as transmission information, the address of the charge / discharge adjustment unit 20 serving as a transmission destination, its own address as a transmission source, and the reply content to the transmission unit 33d. The transmitter 33d applies a pulse voltage to the winding 41 by performing PWM control of the switching unit 32 via the switch controller 33e based on the transmission information. Thereby, the transmission unit 33d transmits the communication frame FS corresponding to the transmission information to the charge / discharge adjustment unit 20 via the transformer 40.

  Then, the charge / discharge adjustment unit 20 receives the communication frame FS transmitted by the charge / discharge management unit 30 via the transformer 40. Since the operation of the charge / discharge adjustment unit 20 when receiving the communication frame FS corresponds to the operation when the charge / discharge management unit 30 receives the communication frame FM, detailed description thereof is omitted.

  In the communication process, the control units 24 and 33 of the units 20 and 30 turn on and off the switching units 23 and 32 at a higher frequency (for example, a basic frequency of 2 MHz) than a switching frequency executed during the charge / discharge process described later. I have control. In the present embodiment, since power transfer and communication are performed via the transformer 40, the switching frequency is differentiated between the power transfer scene and the communication scene, thereby separating the two. Further, in the present embodiment, the switching units 23 and 32 are configured by a bridge circuit composed of four transistors Tr1 to Tr4, so that the on / off control on the positive phase side and the on / off control on the negative phase side are inverted and controlled. By applying a bipolar pulse voltage to each of the windings 41 and 42, a bipolar output of a signal is made possible.

  Referring to FIG. 4 again, based on the communication form as described above, in grasping the voltage state of each unit cell 2, the charge / discharge adjustment unit 20 transmits / receives signals as shown below. By sequentially performing the process on the battery 30, the voltage states of all the cells 2 constituting the battery pack 1 are grasped. First, the charge / discharge adjustment unit 20 transmits a communication frame FM1 whose control content (control signal data) is the detection of the state of the unit cell 2 and the return of the detection result to the target charge / discharge management unit 30. When the charge / discharge management unit 30 receives the communication frame FM <b> 1 from the charge / discharge adjustment unit 20, the charge / discharge management unit 30 detects the voltage state of the unit cell 2 in accordance with an instruction from the charge / discharge adjustment unit 20. Then, the charge / discharge management unit 30 transmits to the charge / discharge adjustment unit 20 a communication frame FS1 having the detection result (the voltage state of the single cell 2) as a reply content (control signal data).

  When the charge / discharge adjustment unit 20 grasps the voltage state of each cell 2 through communication with each charge / discharge management unit 30, the cell 2 is charged or discharged with each cell 2 as a determination target. Or whether to perform both charging and discharging. Thereby, about each single battery 2 which comprises the assembled battery 1, what is not charged / discharged, what is to be charged, its charge amount, what is to be discharged, and its discharge amount are determined. . As described above, when it is assumed that the charge amount needs to be optimized for any two unit cells 2, one unit cell 2 among the plurality of unit cells 2 is charged, and another unit cell 2 is to be discharged, and the remaining unit cell 2 is determined not to perform both charging and discharging.

  Next, the charge / discharge adjustment unit 20 transmits to the discharge-side charge / discharge management unit 30 a communication frame FM2 having the control content (control signal data) as a discharge target and the discharge amount. Here, the amount of discharge included in the control content may be the amount of electric power to be discharged itself, but the corresponding parameter (for example, the number of periodic discharges, the discharge time required for one discharge, The target cell 2 to be discharged may be a target charge amount (SOC)), or information obtained by combining them. Then, the discharge-side charge / discharge management unit 30 charges the communication frame FS2 with the information (for example, transmitted control signal data (echo back)) indicating that the communication frame FM2 has been received as the reply content (control signal data). While transmitting to the discharge adjustment unit 20, according to the control content from the charge / discharge adjustment unit 20, the charge / discharge process described below is performed.

  On the other hand, when the charge / discharge adjustment unit 20 receives the communication frame FM2 from the discharge-side charge / discharge management unit 30, the charge / discharge adjustment unit 20 charges the communication frame FM3, which is a charge target and the control content (control signal data) with the charge amount. It transmits to the discharge management unit 30. The charge side charge / discharge management unit 30 transmits to the charge / discharge adjustment unit 20 a communication frame FS3 whose response content is information indicating that the communication frame FM3 has been received (for example, transmitted control signal data). The charge / discharge process described below is executed in accordance with the control content from the charge / discharge adjustment unit 20.

  Next, the charge / discharge process will be described. In this charging / discharging process, power is transferred between the unit cell 2 to be discharged and the unit cell 2 to be charged via the transformer 40. In the present embodiment, power is transferred through the transformer 40 by a forward method in which power is transferred during on-switching of a circuit on the primary winding side that outputs power.

  In the discharge-side charge / discharge management unit 30, the charge / discharge control unit 33c starts the discharge operation of the unit cell 2 when it is determined that the predetermined period Ta has elapsed since the end of the communication process. This discharge operation is performed based on the discharge amount transmitted from the charge / discharge adjustment unit 20. Specifically, the charge / discharge control unit 33c continuously applies a voltage to the winding 41 for a predetermined period (for example, 100 μsec) by turning on the switching unit 32 via the switch control unit 33e. Then, the charge / discharge control unit 33c performs on / off control of the switching unit 32 via the switch control unit 33e, thereby repeatedly executing the burst-like voltage application operation at a predetermined cycle (for example, 110 μsec) as many times as the number of discharges. . In the present embodiment, the charge / discharge control unit 33c performs the positive phase on control and the reverse phase on control alternately during the on control of the switching unit 32, so that the positive and negative polarities are alternately reversed to the winding 41. The voltage application is performed.

  On the other hand, in the charge-side charge / discharge management unit 30, the charge / discharge control unit 33c starts the charging operation of the unit cell 2 when it is determined that the predetermined period Ta has elapsed since the end of the communication process. Specifically, when the charge / discharge control unit 33c determines the rise of the output pulse of the detection signal from the voltage detection unit 25 based on the detection result from the phase detection unit 33b, the charge / discharge control unit 33c passes the switch control unit 24e. When the switching unit 23 is turned on, and when the falling edge of the output pulse of the detection signal is determined, the switching unit 23 is turned off via the switch control unit 24e. Thereby, the on / off control of the switching unit 23 of the charge side charge / discharge management unit 30 can be performed in synchronization with the on / off control of the switching unit 23 of the discharge side charge / discharge management unit 30. The charge / discharge control unit 33c performs on / off control on the positive phase side or the negative phase side so as to correspond to the voltage polarity appearing alternately in the winding 41.

  When such power transfer ends, in the charge / discharge adjustment unit 20, the charge / discharge adjustment unit 24c determines the elapse of the predetermined period Tb from the end of power transfer based on the information from the phase detection unit 24b, and has been described above. Transition to the communication process. As described above, the charge / discharge time that is periodically executed is, for example, 100 μsec. However, the adjustment of the charge amount of the unit cell 2 targeted for the optimization of the charge amount is about ± 0.2%. Since this is sufficient in many cases, even if the winding is driven by a large power with high winding efficiency, power can be exchanged with sufficiently fine resolution for optimization.

  As described above, according to the present embodiment, in the control unit 24 of the charge / discharge adjustment unit 20, each of the plurality of single cells 2 is determined, and the single cell is charged, discharged, or both charged and discharged. Is determined, and information of the determination result is transmitted to each of the plurality of charge / discharge management units 30. And the control part 33 of the some charging / discharging management unit 30 carries out on-off control of each switching part 23 based on the information of the received determination result, respectively.

  According to this configuration, since the individual switching units 23 can be independently controlled by the plurality of charge / discharge management units 30, the switching unit 23 corresponding to any single cell 2 that needs to exchange power is provided. It can be selectively controlled. When all the switching units corresponding to the assembled battery are collectively controlled, there is a possibility that a switching unit that does not need to be operated may be operated together. Can be suppressed. Therefore, it is possible to minimize the number of switching units 23 to be operated in accordance with power transfer. As a result, it is possible to reduce the power loss associated with the switching operation, improve the efficiency of power transfer and reduce heat generation, and suppress electromagnetic interference (EMI). Moreover, since the electric power which passes the coil | winding 41 with electric power transfer can be enlarged, the core loss (iron loss) of the transformer 40 can be suppressed. Thereby, the amount of charge of each unit cell 2 constituting the assembled battery 1 can be optimized with high efficiency, and the safety and long life of the assembled battery 1 can be improved.

  Moreover, it becomes possible to control these charge / discharge management units 30 centrally by providing the charge / discharge adjustment unit 20 on the relationship which controls the switching part 23 by the several charge / discharge management unit 30 separately, The charge amount of each unit cell 2 can be optimized. Moreover, since the information of the corresponding single battery 2 can be acquired from the plurality of charge / discharge management units 30, the charge amount of each single battery 2 can be optimized while the state of the single battery 2 is fed back. Thereby, the charge amount of each single battery 2 which comprises the assembled battery 1 can be judged in total, and the optimization can be performed accurately.

  Further, according to the present embodiment, in the charge / discharge adjustment unit 20, the control unit 24 performs on / off control of the switching unit 32 and transmits the determination result to each charge / discharge management unit 30 via the transformer 40.

  According to this configuration, signal transmission between the charge / discharge adjustment unit 20 and the charge / discharge management unit 30 can be performed via the transformer 40 that transmits and receives power. Thereby, since it is not necessary to provide a signal line or the like necessary for communication between the units 20 and 30, it is possible to improve the maintenance such as simplification of the apparatus configuration and replacement of the units 20 and 30. In addition, since the withstand voltage can be provided by the winding of the transformer 40, it is not necessary to use a high withstand voltage circuit or IC as each unit 20 and 30, so that an inexpensive apparatus configuration can be realized. In addition, since the individual charge / discharge management units 30 are connected in parallel to each other, even if any one of the unit cell 2 or the charge / discharge management unit 30 fails, as compared with the configuration in which all are connected in series, The possibility of losing the overall function is low, and the reliability of the device can be improved.

  Further, according to the present embodiment, in the charge / discharge adjustment unit 20, the control unit 24 performs on / off control of the switching unit 23 at a frequency higher than the switching frequency at the time of charge / discharge of electric power, thereby determining the determination result of the transformer 40. To each charge / discharge management unit 30.

  According to such a configuration, it is possible to clearly distinguish between power transmission and reception and communication, so that power transmission and communication can be made compatible via the transformer 40. Further, since the communication frequency is high, the communication power input to the transformer 40 can be reduced by the effect of the self-inductance of the transformer 40, and the magnetic permeability of the transformer core is higher than that in the case of power transfer with a low frequency. Therefore, the communication power passing through the transformer 40 is reduced, so that EMI countermeasures can be realized with a simple circuit configuration.

  Further, according to the present embodiment, in the charge / discharge adjustment unit 20, the control unit 24 controls the on / off of the switching unit 23 to locate the single cell 2 (specifically, charge / discharge to which the single cell 2 is connected). An address signal indicating the address of the management unit 30 and a determination result signal indicating the determination result are transmitted. In this case, the determination result signal includes a charge / discharge signal indicating whether charging / discharging is performed or charging / discharging, and a charge / discharge amount signal indicating the charge / discharge amount. Thereby, it is possible to notify the charge / discharge management unit 30 of the necessity of charge / discharge of the unit cell 2 connected to itself.

  Further, in the plurality of charge / discharge management units 30, when the control unit 33 receives the address signal and the determination result signal, the control unit 33 performs on / off control of each switching unit 32, and the received address signal and the determination result signal are charged and discharged. Reply to 20. According to such a configuration, it is determined whether or not the communication from the charge / discharge adjustment unit 20 side has been reliably transmitted to the desired charge / discharge management unit 30 by performing a reply in each charge / discharge management unit 30. be able to.

  In the present embodiment, power transfer between the single cells 2 is performed by a forward method. According to the forward method, since a large current can be taken out, power can be exchanged with high efficiency.

  Moreover, in each unit 20 and 30, switching part 23 and 32 is comprised by the bridge circuit which consists of four switching elements. According to such a configuration, voltages having different polarities can be applied to the windings 41 and 42, so that the polarity (winding direction) of the windings 41 and 42 can be substantially switched. As a result, it is possible to switch the power transfer method between the forward method and the flyback method described later. Thereby, electric power transfer can be performed accurately.

  In addition, in embodiment mentioned above, in the charging / discharging apparatus 10, the charging / discharging adjustment unit 20 is set as the independent structure, However, This embodiment is not limited to this. For example, at least one charge / discharge management unit 30 may have the function of the charge / discharge adjustment unit 20, and the charge / discharge management unit 30 may execute the function together with its own function. Further, the function of the power source 21 may be provided to at least one unit cell 2.

  Further, in the above-described embodiment, in the charge / discharge process, the discharge-side charge / discharge management unit 30 periodically performs the discharge operation and determines the discharge timing mainly, but this embodiment is limited to this. Not. For example, as shown in FIG. 6, when the charge / discharge adjustment unit 20 outputs the trigger signal Stg, the charge-side charge / discharge management unit 30 may execute the discharge operation in synchronization with the trigger signal Stg. .

  Moreover, in embodiment mentioned above, the method of power transfer between the single cells 2 was demonstrated in the charging / discharging process. However, the power of the unit cell 2 to be discharged is not only directly charged by the unit cell 2 to be charged, but also once the power source 21 of the charge / discharge adjustment unit 20 is charged, May be charged to the unit cell 2 to be charged. In addition, when the charging power for the unit cell 2 to be charged is insufficient, the power of the power source 21 may be charged to the unit cell 2 to be charged, and conversely, the discharge amount related to the unit cell 2 to be discharged is charged. If the amount is exceeded, the power supply 21 may be charged with surplus power. In this case, the charge / discharge adjustment unit 20 can charge / discharge the power source 21 by controlling the switching unit 23 as in the charge / discharge operation of the charge / discharge management unit 30.

  In the description of the charging / discharging process described above, power transfer through the transformer 40 is performed by the forward method. However, in the power transfer method, power is transferred when the circuit on the primary winding side that outputs power is switched off. You may carry out by a flyback system. Hereinafter, a charge / discharge process using the flyback method will be described.

  FIG. 7 is an explanatory diagram for explaining the operation of the flyback method as a modification of the charge / discharge device 10 of the present embodiment. In the figure, (a) shows the voltage output waveform of the winding 42 corresponding to the charge / discharge adjustment unit 20, (b) shows the switching waveform of the discharge side charge / discharge management unit 30, and (c) shows The switching waveform of the charge side charge / discharge management unit 30 is shown. (D) shows the magnetic flux waveform in the transformer 40, (e) shows the discharge current of the unit cell 2 to be discharged, and (f) shows the charge current of the unit cell 2 to be charged.

  In the discharge-side charge / discharge management unit 30, the charge / discharge control unit 33c starts the discharge operation of the unit cell 2 when it is determined that the predetermined period Ta has elapsed since the end of the communication process. This discharge operation is performed based on the discharge amount transmitted from the charge / discharge adjustment unit 20. Specifically, the charge / discharge control unit 33c controls the switching unit 32 to be turned on via the switch control unit 33e, thereby causing a current to continuously flow through the winding 41 for a predetermined period (for example, 100 μsec), and then switching. The unit 32 is continuously off-controlled for a period corresponding to the on-control. The charge / discharge control unit 33c repeatedly executes such on / off control a number of times corresponding to the amount of discharge. In the present embodiment, the charge / discharge control unit 33c performs on / off control of the switching unit 32 only by, for example, on / off control on the positive phase side.

  On the other hand, in the charge-side charge / discharge management unit 30, the charge / discharge control unit 33c starts the charging operation of the unit cell 2 when it is determined that the predetermined period Ta has elapsed since the end of the communication process. Specifically, the charge / discharge control unit 33c continuously controls the switching unit 32 to be turned off for a predetermined period (a period corresponding to the above-described on-control period of the discharge-side charge / discharge management unit 30) via the switch control unit 33e. Thereafter, by turning on the switching unit 32, a current is continuously supplied to the winding 41 for a period corresponding to the off control. The charge / discharge control unit 33c repeatedly performs such on / off control a number of times corresponding to the amount of charge. In the present embodiment, since the winding direction of the charging-side winding 41 and the discharging-side winding 41 is the same, the charging / discharging control unit 33c performs on / off control of the switching unit 32, for example, in reverse phase Only on-off control on the side.

  According to such a form, power transfer between the single cells 2 (or between the power source 21 and the single cells 2) is performed by a flyback method. Regardless of the primary winding voltage that outputs electric power, the voltage of the secondary winding that inputs electric power can be set, so that the voltage difference between the single cells 2 becomes small, and it is difficult to control power transfer with the forward method. There is an advantage of using the flyback method in the case where the amount of power is transferred or a small amount of electric power is transferred close to the target charge amount.

(Second Embodiment)
FIG. 8 is a schematic diagram illustrating a main part of the configuration of the charge / discharge device 10 according to the second embodiment. The second embodiment is different from that of the first embodiment in the charge / discharge device 10 in the configuration of the switching unit 23 of the charge / discharge adjustment unit 20 and the switching unit 32 of the charge / discharge management unit 30.

  In this embodiment, each switching part 23 and 32 is comprised from one transistor Tr (for example, FET: Field effect transistor) provided in the power line. A body diode D is connected to the transistor Tr in an antiparallel manner. In each unit 20, 30, the transistor Tr is connected to the control units 24, 33, and is on / off controlled by signals from the control units 24, 33.

  Furthermore, in the present embodiment, each unit 20 and 30 has a snubber circuit in which a parallel circuit of a capacitor C and a resistor R is connected in series to the diode D in order to suppress a rapid voltage rise in the circuit. It is connected in parallel to the winding 41.42.

  In the charge / discharge adjustment unit 20, the output voltage is higher than the reference voltage (for example, the voltage of the power source 21) between the power source 21 and the switching unit 23 when power is supplied from the winding 42 side to the power source 21 side. A booster circuit 27 that performs a boosting operation is connected so as to be higher. The booster circuit 27 is provided to realize the charging operation from the single battery 2 to the power supply 21 even in the case where the voltage of the power supply 21 is higher than the voltage of each single battery 2. In this case, it is preferable to provide a step-down circuit that performs a step-down operation in order to prevent an excessive voltage from being applied to the unit cell 2 side when power is supplied from the power source 21 side to the unit cell 2 side. However, in this embodiment, the step-down circuit is omitted by operating the switching unit 23 as a chopper switch of the step-down regulator.

  In the present embodiment, the winding 42 corresponding to the charge / discharge adjustment unit 20 and the winding 41 corresponding to the charge / discharge management unit 30 are all wound around the transformer 40 so as to have the same polarity. In this case, power transfer between the single cells 2 and power transfer between the single cells 2 and the power source 21 are performed by the above-described forward method.

  Thus, according to this embodiment, the structure of the switching parts 23 and 32 can be simplified.

  The configuration of the switching units 23 and 32 of the units 20 and 30 may be configured from a single switch as shown in this embodiment (single switch configuration) or as shown in the first embodiment. Alternatively, a bridge circuit composed of four switches may be used (full bridge configuration). The switching units 32 of the plurality of charge / discharge management units 30 may also have a single switch configuration or a full bridge configuration. In this case, the method of power transfer between the two parties is determined according to the combination of the polarities of the windings 41 and 42 corresponding to the units 20 and 30 and the configuration of the switching units 23 and 32. .

Specifically, when the windings 41 and 42 corresponding to the units 20 and 30 have the same polarity, the method of power transfer between the unit cells 2 and between the power source 21 and the unit cell 2 is as follows. Depending on the configuration of the switching units 23 and 32 of the units 20 and 30, the selection can be made as shown in the table below.

  As shown in the table, when the windings 41 and 42 connected to the charge / discharge target are each in the positive phase, the power transmission / reception method is determined according to the configuration of the switching units 23 and 32. Specifically, when both of the switching units 23 and 32 included in the units 20 and 30 have a single switch configuration, the power transfer method is a forward method. On the other hand, when one or both of the switching units 23 and 32 have a full bridge configuration, the power exchange method can select either the forward method or the flyback method.

On the other hand, when the winding 42 corresponding to the charge / discharge adjustment unit 20 has a reverse polarity with respect to the winding 41 corresponding to each charge / discharge management unit 30, between the single cells 2 and the power supply The method of power transfer between the unit 21 and the unit cell 2 can be selected as shown in the following table according to the configuration of the switching units 23 and 32 of the units 20 and 30.

  As shown in the table, in the case of power transfer between the single cells 2, when both of the switching units 32 included in the charge / discharge management unit 30 connected to the charge / discharge target have a single switch configuration, the power transfer method is forward. It becomes a method. On the other hand, when either one or both of the switching units 32 have a full bridge configuration, either the forward method or the flyback method can be selected as the power transfer method. In the case of power transfer between the unit cell 2 and the power source 21, when both the switching units 23 and 32 included in the units 20 and 30 connected to the charge / discharge target have a single switch configuration, The method is a flyback method. On the other hand, when either one or both of the switching units 23 and 32 have a full bridge configuration, the power transmission / reception method to be charged / discharged can be selected from either the forward method or the flyback method.

  Further, as shown in FIG. 9, the plurality of charge / discharge management units 30 are divided into two groups Ga and Gb, and the windings 41 of the charge / discharge management units 30 belonging to one group Ga and the other group Ga are divided. The winding 41 of each charge / discharge management unit 30 to which it belongs may have a reverse polarity. In this case, even when the switching unit 32 has a single switch configuration, power transfer between the single cells 2 belonging to the group Ga and the single cells 2 belonging to the group Gb can be performed by a flyback method. In this case, the switching unit 23 of the charge / discharge adjustment unit 20 has a full bridge configuration, so that the power transfer between the power source 21 and each unit cell 2 is convenient for the flyback method and the forward method. You can choose.

  As mentioned above, although the charging / discharging apparatus concerning embodiment of this invention was demonstrated, this invention is not limited to embodiment mentioned above, It cannot be overemphasized that various deformation | transformation are possible within the scope of the invention. . For example, the charging / discharging device can optimize charging / discharging of each unit cell for an assembled battery that functions as a battery for various devices such as an electric vehicle and a personal computer in addition to a battery for a hybrid vehicle.

DESCRIPTION OF SYMBOLS 1 assembled battery 2 single battery 3 DC / DC converter 4 inverter 5 motor 6 generator 7 charging circuit 10 charging / discharging apparatus 20 charging / discharging adjustment unit 21 power supply 23 switching part 24 control part 24a receiving part 24b phase detection part 24c charging / discharging adjustment part 24d Transmission unit 24e Switch control unit 25 Voltage detection unit 26 Filter circuit 27 Booster circuit 30 Charge / discharge management unit 32 Switching unit 33 Control unit 33a Reception unit 33b Phase detection unit 33c Charge / discharge control unit 33d Transmission unit 33e Switch control unit 34 Status detection Section 35 Voltage detection section 36 Filter circuit 40 Transformer 41 Winding 42 Winding

Claims (6)

A charge / discharge device that charges and discharges each of a plurality of single cells via a transformer,
A plurality of switching means provided for each unit cell, each interposed between the unit cell and the winding of the transformer;
A plurality of charge / discharge management means for controlling on / off of each of the plurality of switching means;
Charge / discharge adjustment means for determining whether to charge, discharge, or perform both charging and discharging, with each of the plurality of unit cells as a determination target,
The charge / discharge adjustment means transmits a determination result to each of the plurality of charge / discharge management means,
The plurality of charge / discharge management means perform on / off control of each of the switching means based on the received determination result. Power supply,
A main switching means interposed between the power source and the transformer winding;
2. The charging / discharging device according to claim 1, wherein the charging / discharging adjusting unit controls on / off of the main switching unit and transmits the determination result to each charging / discharging managing unit via the transformer.   The charge / discharge adjustment means transmits the determination result to each charge / discharge management means via the transformer by performing on / off control of the main switching means at a frequency higher than a switching frequency at the time of charge / discharge of electric power. The charging / discharging device according to claim 2.   4. The charging / discharging adjustment unit according to claim 3, wherein the charging / discharging adjustment unit controls the on / off of the main switching unit to transmit an address signal indicating a location of the unit cell and a determination result signal indicating the determination result. Discharge device.   5. The charge / discharge signal according to claim 4, wherein the determination result signal includes a charge / discharge signal indicating whether charging / discharging is performed or not, and a charge / discharge amount signal indicating a charge / discharge amount. Discharge device.   When the plurality of charge / discharge management means receives an address signal and a determination result signal, each of the switching means is controlled to turn on and off, and the received address signal and the determination result signal are returned to the charge / discharge adjustment means. The charging / discharging device according to claim 4 or 5.

Images