JP5250953B2 - Power storage circuit - Google Patents

Description

  The present invention relates to a power storage circuit using a power storage element that charges and discharges electric power.

  In recent years, automobiles equipped with an idling stop function for stopping the engine drive when the vehicle stops and an electric power steering for reducing the engine load have been put on the market in order to consider the environment and improve fuel efficiency. In addition, hybrid systems and electric turbo systems for actively supplementing engine driving are expected to become popular in the future. Further, various proposals from conventional mechanical hydraulic control to electrical hydraulic control have also been made for vehicle braking.

  In this way, the power required for automobiles in the future tends to increase significantly. However, it is difficult to supply a large amount of power instantaneously with a battery that is a conventional power supply source. When the battery becomes abnormal, the system may not work.

  On the other hand, for example, Patent Document 1 proposes a power storage circuit as an auxiliary power source that can sufficiently supply power including when the battery is abnormal.

  FIG. 4 is a schematic circuit diagram of such a storage circuit. A capacitor cell 110 composed of a large-capacity electric double layer capacitor is used for the storage element. A capacitor pack 112 is configured by connecting a plurality of these in series. Since the capacitor pack 112 is connected to a power source such as a battery, the capacitor cell 110 is charged by this power source.

  Each capacitor cell 110 is connected in parallel with a load such as a balance resistor 114 in order to balance the voltage between both ends thereof. A relay switch 116 is connected between each capacitor cell 110 and each balance resistor 114. The relay switch 116 includes a normally-open relay contact 116a that forms a switch portion and an electromagnetic coil 116b that drives the switch portion. Each electromagnetic coil 116b is connected in parallel between the power source and the ground, and the accessory switch 118 is connected to the power source side. Therefore, when the accessory switch 118 is turned on, all the electromagnetic coils 116b are driven and the relay switch 116 is turned on.

  Next, a schematic operation of such a power storage circuit will be described.

  When the vehicle is started, the accessory switch 118 is turned on by the ignition key. As a result, as described above, all the relay switches 116 are turned on, and the capacitor cell 110 and the balance resistor 114 are connected in parallel. Accordingly, power is applied to each capacitor cell 110, charging starts, and the balance resistor 114 is connected, so that the voltage across each capacitor cell 110 is automatically adjusted to be equal. The Thereby, it is possible to prevent the capacitor cell 110 from being overcharged and to extend its life.

Next, when the vehicle is stopped, the accessory switch 118 is turned off. As a result, all the relay switches 116 are turned off, and the capacitor cell 110 and the balance resistor 114 are disconnected. As a result, since each capacitor cell 110 is independent of the wiring, it is in a state of retaining the charge that was charged before the vehicle stopped. As a result, unnecessary discharge from the capacitor cell 110 is prevented, and power storage is continued for a long time. By such an operation, it becomes possible to supply electric power provided when the engine is restarted.
JP-A-10-201091

  According to the above storage circuit, it is possible to prevent overcharge of the capacitor cell 110 and extend its life, or to suppress unnecessary discharge of the capacitor cell 110 when the vehicle is stopped and to supply power when the engine is restarted. If the capacitor cell 110 is left for a long time while being charged when stopped, a spontaneous discharge occurs, and the voltage at both ends gradually decreases. At this time, since the capacitor cell 110 has variations in characteristics, the voltage across the capacitor cell 110 due to natural discharge also varies. When the vehicle is started in this state, the relay switch 116 is turned on and the balance resistor 114 is connected to the capacitor cell 110, so that the voltage across the capacitor cell 110 is automatically set to a constant value by the balance resistor 114. Although it is adjusted, when the vehicle is left for a long time, depending on the variation width of the self-discharge of the capacitor cell 110, the time until the voltage balance at the time of starting the vehicle becomes constant (hereinafter referred to as the balance time). It will be an order of several hours and will become long. In the meantime, some of the capacitor cells 110 may be in an overvoltage state, thereby shortening the life, and thus the reliability may be lowered.

  In order to avoid this, a configuration may be adopted in which voltage balance is intermittently obtained when the vehicle is stopped after use. On the other hand, in the conventional power storage circuit, an example is described in which a manual operation is performed by a push button switch (not shown) provided in the passenger compartment when the vehicle is stopped. Had the problem of being extremely difficult.

  The present invention solves the above-described conventional problems, and provides a power storage circuit that can suppress unnecessary discharge of a power storage element and can achieve high reliability by automatically performing an intermittent voltage balance operation. Objective.

In order to solve the above-described conventional problems, a power storage circuit of the present invention includes a power storage element unit including a plurality of capacitor power storage elements in which external power is charged and discharged by an external charge / discharge circuit, and the power storage element. A balance circuit having switch means connected in parallel; a control circuit for detecting the voltage of the power storage element to control on / off of the switch means; and a switch element for turning on / off power supply from the power storage element unit to the control circuit; , Wherein the control circuit turns off the switch element, stops the control circuit, and turns off the switch means. A second step in which the control circuit is activated by turning on the switch element by an external activation signal; and the switch means And a third step of making the voltage balance of the power storage element constant, and when the voltage balance becomes constant, the process returns to the first step, and the start signal is used to perform the second step and the third step. The control circuit is stopped until the signal is received .

Thus, since the time of end of use is not supplied power to the control circuit, but the switch means is turned off, power is supplied to the more controlled circuit activation signal is intermittently transmitted from the outside at the time of stopping, the electric storage device Voltage balance can be taken. As a result, the object can be achieved.

  According to the power storage circuit of the present invention, since the power of the power storage element is not consumed when stopped, unnecessary discharge of the power storage element can be suppressed, and the voltage balance is intermittently made constant. Thus, a storage circuit capable of ensuring high reliability can be realized.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Here, a case where the power storage circuit is applied to a vehicle will be described.

(Embodiment 1)
FIG. 1 is a block circuit diagram of a power storage circuit according to Embodiment 1 of the present invention.

  In FIG. 1, a power storage element 1 that charges and discharges electric power includes an electric double layer capacitor, and a plurality of these are connected in series to form a power storage element unit 2. A balance circuit 3 is connected to each of the storage elements 1 in parallel. The balance circuit 3 is composed of a circuit in which a switch means 5 made of a transistor and a resistor 7 are connected in series. For this reason, when the switch means 5 is turned on, the resistor 7 is connected to both ends of the power storage element 1, and as a result of the discharge by the resistor 7, the voltage of the power storage element 1 can be controlled to decrease.

  The balance circuit 3 is connected to a voltage monitor selection switch 9 that selects voltages V1 to Vn (n is the number of the storage elements 1 + 1) at one end thereof. The voltage monitor selection switch 9 is configured by a multiplexer, for example, and has a function of selecting one of the voltages V1 to Vn by a voltage selection signal SLV indicating which voltage V1 to Vn is selected. Further, the voltage monitor selection switch 9 has a floating configuration in which none of the voltages V1 to Vn is selected when the supply of the power supply voltage (DC5V in the first embodiment) is cut off. As a result, when the power source of the voltage monitor selection switch 9 is turned off at the time of stopping, both ends of each balance circuit 3 are all insulated by the voltage monitor selection switch 9. Thus, the electricity storage element 1 can be prevented from being discharged.

  A balance circuit selection switch 11 is connected to the on / off control terminal of each switch means 5 (the base terminal of the transistor in the first embodiment). The balance circuit selection switch 11 is also composed of, for example, a multiplexer, and an arbitrary switch means 5 is selected by a switch means selection signal SLB indicating which switch means 5 is to be selected, and a control circuit (described later) is selected. ) To transmit the ON signal Hi. As a result, any balance circuit 3 can be operated according to the voltage balance state of the power storage elements 1, so that a voltage balance can be individually achieved for each power storage element 1.

  A control circuit 13 is connected to the voltage monitor selection switch 9 and the balance circuit selection switch 11. The control circuit 13 includes a microcomputer and a peripheral circuit (none of which is shown) that generates various signals such as the ON signal Hi and transmits / receives them, and as described above, the voltage selection signal of the voltage monitor selection switch 9. The SLV, the switch selection signal SLB of the balance circuit selection switch 11 and the ON signal Hi are transmitted, and the voltage (one of V1 to Vn) selected by the voltage monitor selection switch 9 is set to the two resistors 15 and 17. The voltage signal Vin as the midpoint voltage when the resistance is divided is received. Therefore, the voltage signal Vin has a value proportional to the voltage Vi (i = 1 to n). The control circuit 13 is provided with other terminals for transmission / reception, which will be sequentially described.

  The driving power (the voltage is set to DC5V) for the voltage monitor selection switch 9, the balance circuit selection switch 11, and the control circuit 13 is supplied when the switch element 19 is turned on. The on / off operation of the switch element 19 is controlled by an external activation signal Wake described later or a power control signal Lo of the control circuit 13.

  The switch element 19 is composed of, for example, a P-channel MOSFET, and its source terminal S is connected to the highest voltage V1 of the power storage element 1. Further, the first resistor 21 is connected between the source terminal S and the gate terminal G. The gate terminal G is connected to the control circuit 13 through the second resistor 23. On the other hand, a regulator 27 that generates a constant voltage (DC 5 V) is connected to the drain terminal D via a diode 25 for preventing backflow. As a result, a constant voltage of DC5V is obtained from the voltage V1 and supplied to the voltage monitor selection switch 9, the balance circuit selection switch 11, and the drive voltage input terminal 29 of the control circuit 13. Accordingly, the voltage supply of DC 5V is controlled by turning on / off the switch element 19.

  A starting isolation type signal transmission means 31 is connected to a connection point between the control circuit 13 and the second resistor 23. The start-up insulated signal transmission means 31 is composed of, for example, a photocoupler, and a connection point between the control circuit 13 and the second resistor 23 is connected to the collector side of the phototransistor 33. The emitter side of the phototransistor 33 is connected to the ground.

  On the other hand, an external control circuit 37 is connected to the anode side of the light emitting diode 35 of the start-up insulated signal transmission means 31. The external control circuit 37 is composed of a microcomputer and peripheral circuits like the control circuit 13 and is used for vehicle control including charge / discharge control of the power storage element unit 2. An activation signal Wake is transmitted from the external control circuit 37 to the light emitting diode 35. The cathode side of the light emitting diode 35 is connected to the ground via a resistor 39.

  The external control circuit 37 is driven with a constant voltage of DC5V, like the control circuit 13, but this power source converts the output voltage of the battery 41 of the low voltage system (for example, DC12V) mounted on the vehicle into DC5V by the regulator 42. Supply. Therefore, power is obtained from a power source independent of the control circuit 13. Note that a low voltage load 44 is connected to the battery 41 via a battery ignition switch 43. The battery ignition switch 43 has a function of transmitting an ignition signal IG indicating the ignition on / off state. In the configuration shown in FIG. Sending.

  The external control circuit 37 and the control circuit 13 exchange data with each other. First, transmission from the control circuit 13 to the external control circuit 37 is performed by the data transmission insulated signal transmission means 45. The configuration of the data transmission insulated signal transmission means 45 is the same as that of the startup insulated signal transmission means 31, but the positions of the phototransistor 47 and the light emitting diode 49 are reversed.

  A specific data transmission method is as follows. First, voltage data and the like of the storage element 1 are transmitted from the control circuit 13 to the light emitting diode 49 as a data signal Dout. In response to this, the phototransistor 47 is turned on / off according to the data signal to return to the electric signal, and is input to the external control circuit 37 as the data signal Din.

  Similarly, the reception from the external control circuit 37 to the control circuit 13 is performed by the data receiving insulated signal transmission means 51. The configuration of the data reception insulated signal transmission means 51 is the same as the configuration of the startup insulation signal transmission means 31.

  A specific data receiving method is as follows. First, data such as a voltage data transmission request for the storage element 1 is transmitted from the external control circuit 37 to the light emitting diode 53 as a data signal Dout. In response to this, the phototransistor 55 is turned on / off in response to the data signal to return to the electric signal and input to the control circuit 13 as the data signal Din. By such control, transmission / reception between the control circuit 13 and the external control circuit 37 is performed.

  Among the components described above, the power storage circuit 57 is configured by components surrounded by a thick dotted line in FIG. Further, a main power source 59 that is a power source for charging the power storage element 1 is connected to the power storage circuit 57 via a main power source ignition switch 61 and a charge / discharge circuit 63 of the power storage element 1. Here, the main power source 59 is composed of a high-voltage secondary battery (for example, a nickel metal hydride battery or a lithium ion battery). Therefore, a high-voltage load 65 such as a starter or a vehicle driving motor for a hybrid vehicle is also connected to the output of the main power source ignition switch 61. Further, since the charge / discharge circuit 63 is controlled by the external control circuit 37, wiring for transmitting the charge / discharge control signal cont is connected between the two. Note that the charge / discharge circuit 63 is configured to completely turn off the input and output when stopped. Further, since the main power ignition switch 61 is on / off controlled in response to the ignition signal IG from the battery ignition switch 43, wiring for this purpose is connected between the two.

  Note that the ground of the power storage circuit 57 is configured independently of the grounds of the other components (the ground symbols in FIG. 1 are shown as different from each other). As a result, the storage circuit 57 is independent of other circuit configurations in combination with the use of the starting isolation signal transmission means 31, the data transmission isolation signal transmission means 45, and the data reception isolation signal transmission means 51. It will be. As a result, for example, when the power storage circuit 57 fails, it can be replaced with a non-defective power storage circuit 57 very easily.

  Furthermore, although the configuration in which only one power storage circuit 57 is provided in the first embodiment, a plurality of power storage circuits 57 are provided according to the power specifications required by the load 65, and one external control circuit 37 is provided. It is good also as a structure controlled by. In this case, since the power storage circuit 57 is independent from other circuit configurations, a plurality of power storage circuits 57 can be connected with a very simple configuration.

  Next, the operation of the power storage circuit 57 will be described.

  First, the battery ignition switch 43 is turned on to start the vehicle. As a result, power is supplied to the low-voltage load 44 and the main power ignition switch 61 is also turned on, and power is supplied to the load 65. For example, the starter operates to drive the engine to drive the vehicle. Startup is performed. At the same time, an ignition signal IG indicating an ON state is transmitted from the battery ignition switch 43 to the external control circuit 37. As a result, the charge / discharge control signal cont is transmitted to the charge / discharge circuit 63 to instruct to start charging the power storage element 1 of the power storage circuit 57.

  Further, the external control circuit 37 transmits an activation signal Wake to activate the power storage circuit 57. As a result, the light emitting diode 35 of the start-up insulated signal transmission means 31 is turned on, and the phototransistor 33 is also turned on.

  Here, until the phototransistor 33 is turned on, the input / output of the charge / discharge circuit 63 is completely turned off, so that the highest voltage V1 of the power storage element 1 is applied to the source terminal S of the switch element 19. The source terminal S is connected to the gate terminal G via the first resistor 21, and the gate terminal G is connected to the control circuit 13 via the second resistor 23, but the control circuit 13 is driven. When not, the connection point between the second resistor 23 and the control circuit 13 is in an electrically floating state. Therefore, since the source terminal S and the gate terminal G become equal voltage V1, the switch element 19 is in an OFF state.

  When the phototransistor 33 is turned on at this time, the connection point between the second resistor 23 and the control circuit 13 is connected to the ground via the phototransistor 33. As a result, the voltage at the gate terminal G is lower than the voltage V1 according to the resistance values of the first resistor 21 and the second resistor 23 with respect to the voltage V1 at the source terminal S. As a result, an ON signal is input to the gate terminal G, so that the switch element 19 is turned ON. Therefore, since the voltage V1 is applied to the regulator 27 via the diode 25, the regulator 27 outputs a constant voltage (DC5V). This voltage is supplied to the control circuit 13, the voltage monitor selection switch 9, and the balance circuit selection switch 11, and the storage circuit 57 is activated. As a result, the control circuit 13 keeps the switch element 19 on and keeps supplying a constant voltage, so that the voltage at the connection point between the second resistor 23 and the control circuit 13 is maintained at the ground level. To the ground level.

  Thereafter, the storage element 1 is charged with the power of the main power supply 59 via the charge / discharge circuit 63. At this time, the external control circuit 37 transmits a voltage data transmission request signal Dout to the power storage circuit 57. As a result, the control circuit 13 transmits the voltage selection signal SLV to the voltage monitor selection switch 9. The voltage monitor selection switch 9 selects a voltage (any one of V1 to Vn) designated by the voltage selection signal SLV, and the control circuit 13 reads the voltage signal Vin. Such an operation is repeated to read data of all voltages V1 to Vn. All voltage data is transmitted from the control circuit 13 to the external control circuit 37 through the data transmission insulating signal transmission means 45 as the data signal Dout. The external control circuit 37 continues to charge the power storage element 1 while controlling the charge / discharge circuit 63 so as to satisfy the optimum condition from the obtained voltage data until the battery is fully charged.

  When the storage element 1 is fully charged, the external control circuit 37 issues a command to stop charging to the charge / discharge circuit 63. Thereby, start-up of the electrical storage circuit 57 is completed.

  Next, it is assumed that the load 65 that consumes a large current operates. As a result, the main power supply 59 causes a voltage drop and cannot supply power to the load 65 with a stable voltage. Therefore, the electric power of the storage element 1 is supplied to the load 65 through the charge / discharge circuit 63 so as to compensate for the voltage drop. As a result, a stable voltage can be continuously supplied to the load 65 even if a voltage drop occurs.

  When the consumption of the large current is finished, the voltage of the main power supply 59 returns, and then the power storage element 1 is fully charged again to prepare for the next voltage drop compensation.

  As described above, when the storage element unit 2 is charged by the charge / discharge circuit 63 during the operation of the storage circuit 57, the control circuit 13 uses the voltage monitor selection switch 9 and the balance circuit selection switch 11 to control the storage element 1. Control the voltage balance to be constant.

  Next, a case will be described in which the use of the vehicle is terminated and the battery ignition switch 43 is turned off. As a result, the main power source ignition switch 61 is also turned off, so that the power supply to the load 65 is cut off and an ignition signal IG indicating the ignition off state is transmitted to the external control circuit 37. Note that the electric power of the battery 41 is always supplied through the regulator 42 in order to perform the minimum necessary control even when the external control circuit 37 is stopped. As a result, the external control circuit 37 transmits a charge / discharge control signal cont and issues a command to completely turn off the input / output of the charge / discharge circuit 63. As a result, the power storage element 1 becomes independent from the wiring system of the main power supply 59. Therefore, unnecessary discharge of the electricity storage element 1 is suppressed.

  At this time, since the control circuit 13 is still driven by the electric power of the power storage element 1, the connection point between the second resistor 23 and the control circuit 13 is electrically floated to stop this. As a result, since the source voltage and the gate voltage of the switch element 19 become equal as described above, the switch element 19 is turned off, and the control circuit 13, the voltage monitor selection switch 9, and the balance circuit selection switch 11 are all turned off. become. Thereby, since the voltage monitor selection switch 9 has a floating configuration, none of the voltages V1 to Vn is selected. Further, the start-up insulated signal transmission means 31, the data transmission insulated signal transmission means 45, and the data reception insulated signal transmission means 51 are not directly connected to the wiring system of the external control circuit 37. From these things, since the electrical storage element 1 will be in the electrically floating state, unnecessary discharge is not performed.

  If the vehicle is left in this state, the discharge from the circuit connected to the power storage element 1 is extremely suppressed, but self-discharge due to the internal resistance of the power storage element 1 occurs. As a result, the voltage across the storage element 1 gradually decreases, but at this time, a difference occurs in the voltage drop rate due to the internal resistance variation of the storage element 1, and the voltage value across the storage element 1 varies. . Therefore, in order to reduce variation, the following voltage balance operation is automatically performed for each predetermined condition (for example, once a day).

  Since the external control circuit 37 is always operating, the external control circuit 37 measures the predetermined time. When the predetermined time elapses, the external control circuit 37 issues a start signal Wake. As a result, the control circuit 13 receives the activation signal Wake and performs exactly the same operation as that when the power storage circuit 57 is activated, so that the switch element 19 is turned on. As a result, the electric power of the electric storage element 1 is stabilized at a constant voltage (DC5V) by the regulator 27, and the electric storage circuit 57 is activated.

  Next, the control circuit 13 controls the voltage monitor selection switch 9 to detect the voltages V1 to Vn. The method is also exactly the same as that at the time of starting the power storage circuit 57 described above. The control circuit 13 obtains the voltage across each power storage element 1 from the obtained voltage data and controls the balance circuit selection switch 11 to operate the balance circuit 3 of the power storage element 1 having a high voltage across both ends. Specifically, first, the balance circuit selection switch 11 transmits a switch means selection signal SLB for selecting the switch means 5 of the target storage element 1. As a result, the balance circuit selection switch 11 transmits the switch means on signal Tri (i = 1 to n−1) to the selected switch means 5. As a result, the selected switch means 5 is turned on, the electric power of the storage element 1 is discharged through the resistor 7 and the voltage is lowered.

  Such an operation is repeated, and the voltage balance becomes constant when the voltages at both ends of all the power storage elements 1 become equal. Thus, the voltage balance operation is completed. At this time, similarly to the end of the vehicle use, the control circuit 13 turns off the switch element 19 by electrically floating the connection point with the second resistor 23. As a result, the operation of the power storage circuit 57 is stopped, and the state is the same as when the power is stopped.

  Since the voltage balance of the electricity storage device 1 is intermittently made constant in this way, the possibility of overvoltage to the electricity storage device 1 due to charging in a state where the voltage balance is lost at the start of the vehicle can be reduced. High reliability can be obtained.

  However, if the voltage of the storage element 1 is overdischarged by the voltage detection operation, the control circuit 13 transmits an overdischarge signal to the external control circuit 37 via the data transmission insulating signal transmission means 45. At the same time, the voltage balancing operation is stopped in order to avoid shortening the life of the electricity storage device 1. By receiving the overdischarge signal, the external control circuit 37 does not transmit a start signal Wake for every predetermined time thereafter, and ensures reliability by warning the driver that the vehicle is overdischarged when the vehicle is started. Yes.

  With the above configuration and operation, unnecessary discharge of the electricity storage device 1 during stoppage is suppressed as much as possible, and the intermittent voltage monitoring operation and voltage balancing operation are automatically performed to reduce the possibility of overvoltage and overdischarge. A power storage circuit with high reliability was realized.

(Embodiment 2)
FIG. 2 is a block circuit diagram of a power storage circuit according to Embodiment 2 of the present invention.

  2, the same components as those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted. That is, the parts that characterize the configuration of FIG. 2 are as follows.

  1) The power storage component 73 was connected to the drive voltage input terminal 29 of the control circuit 13.

  2) The control circuit 13 is made to maintain the power saving state when stopped by the power of the power storage component 73. The power storage component 73 has a capacity value that allows the control circuit 13 to maintain a power saving state for about one month.

  3) Along with this, the activation signal Wake generated from the external control circuit 37 is transmitted to the activation terminal 75 of the control circuit 13. For this purpose, the collector terminal of the phototransistor 33 is connected to the output of the regulator 27, the resistor 77 is connected to the emitter terminal of the phototransistor 33, and the connection point between the emitter terminal and the resistor 77 is the start terminal 75 of the control circuit 13. Connected to.

  4) A selection switch power switch 79 for controlling on / off the power to the voltage monitor selection switch 9 and the balance circuit selection switch 11 by the control circuit 13 is provided.

  Other configurations are the same as those in the first embodiment. The power storage component 73 may be a capacitor or a secondary battery, but in the second embodiment, a capacitor having a capacitance value of several farads is used.

  Next, the operation of the power storage circuit 57 having such a configuration will be described focusing on differences from the first embodiment.

  First, when the battery ignition switch 43 is turned on by starting the vehicle, the main power supply ignition switch 61 is turned on to drive the engine, and the external control circuit 37 transmits a charge / discharge control signal cont to the charge / discharge circuit 63, A command is issued to start charging the power storage element 1. This operation is the same as in the first embodiment.

  Further, the external control circuit 37 transmits an activation signal Wake to activate the power storage circuit 57. As a result, the light emitting diode 35 of the start-up insulated signal transmission means 31 is turned on, and the phototransistor 33 is also turned on.

  Here, the control circuit 13 is in a power saving state until the phototransistor 33 is turned on. The drive voltage to the control circuit 13 at this time is supplied from the power storage component 73. That is, since the control circuit 13 in the power saving state has a very small current consumption, the power storage component 73 having a capacitance value of several farads can be sufficiently driven. In the power saving state, the control circuit 13 turns off the switch element 19 and the selection switch power switch 79 and the phototransistors 33 and 55 are off. Will be supplied only to. As a result, the control circuit 13 can be driven by the power storage component 73 for a long period (about one month).

  When the phototransistor 33 is turned on at this time, the current from the power storage component 73 flows to the ground through the resistor 77, so that a voltage is generated at the emitter terminal of the phototransistor 33. Since this corresponds to the activation signal Wake, the control circuit 13 is returned from the power saving state to the normal operation mode and activated by being input to the activation terminal 75 of the control circuit 13. Thereby, the control circuit 13 immediately turns on the switch element 19 by setting the power control signal Lo to the ground level as in the first embodiment. As a result, the voltage V 1 is converted to DC 5 V by the regulator 27 and input to the drive voltage input terminal 29 of the control circuit 13. Therefore, a stable voltage is supplied thereafter. At the same time, since the power consumed by the power saving state of the control circuit 13 is stored in the power storage component 73 and is fully charged, it is possible to prepare for the next power saving state.

  Further, the control circuit 13 transmits the selection switch power signal SP to turn on the selection switch power switch 79. As a result, power is supplied to the power supply monitor selection switch 9 and the balance circuit selection switch 11.

  With this operation, the power storage circuit 57 is activated. The subsequent operation is the same as that of the first embodiment, and the power storage element 1 is charged by controlling the charge / discharge circuit 63 while monitoring the voltage of each power storage element 1. When the storage element 1 is fully charged, the external control circuit 37 issues a command to stop charging to the charge / discharge circuit 63. Thereby, start-up of the electrical storage circuit 57 is completed.

  Next, when the load 65 that consumes a large current operates, the power of the power storage device 1 is supplied to the load 65 through the charge / discharge circuit 63 so as to compensate for the voltage drop of the main power supply 59. As a result, a stable voltage can be continuously supplied to the load 65 even if a voltage drop occurs. When the consumption of the large current is completed, the voltage of the main power supply 59 returns, and then the power storage device 1 is fully charged again to prepare for the next voltage drop compensation.

  When the storage element unit 2 is charged by the charging / discharging circuit 63, the control circuit 13 controls the voltage balance of the storage element 1 to be constant with the voltage monitor selection switch 9 and the balance circuit selection switch 11. .

  Next, the end of use of the vehicle will be described. When the battery ignition switch 43 is turned off, the main power supply ignition switch 61 is also turned off, the power supply to the load 65 is cut off, and an ignition signal IG indicating the ignition off state is transmitted to the external control circuit 37. The As a result, the external control circuit 37 transmits a charge / discharge control signal cont and issues a command to completely turn off the input / output of the charge / discharge circuit 63. As a result, the power storage element 1 becomes independent from the wiring system of the main power supply 59. Therefore, unnecessary discharge of the electricity storage element 1 is suppressed.

  At this time, the control circuit 13 is still driven by the electric power of the power storage element 1, so that the switch element 19 is turned off by setting the electric power control signal Lo to be electrically floated in order to stop this. . At the same time, the selection switch power switch 79 is also turned off. As a result, as in Embodiment 1, the power storage element 1 is in an electrically floating state, so that unnecessary discharge is not performed. Thereafter, the control circuit 13 enters the power saving state while receiving the power supply from the power storage component 73 and maintains it.

  If the vehicle is left in this state, the voltage value at both ends of the power storage element 1 varies due to the reason described in the first embodiment. Therefore, in order to reduce the variation, the following voltage balance operation is performed for each predetermined condition (for example, 1 Automatically once a day).

  The external control circuit 37 issues a start signal Wake when a predetermined time has elapsed. As a result, the control circuit 13 receives the activation signal Wake and returns to the normal operation mode by performing exactly the same operation as when the power storage circuit 57 is activated. As a result, the control circuit 13 turns on the switch element 19 and the power switch 79 for selection switch. As a result, the electric power of the electric storage element 1 is stabilized at a constant voltage (DC5V) by the regulator 27, and the electric storage circuit 57 is activated.

  Next, the control circuit 13 controls the voltage monitor selection switch 9 in the same manner as in the first embodiment to detect the voltages V1 to Vn, and controls the balance circuit selection switch 11 to store the voltage across the high voltage. 1 balance circuit 3 is operated. Thereby, the electric power of the electrical storage element 1 is discharged and a voltage falls. Such an operation is repeated, and the voltage balance operation is completed when the voltage balance becomes constant. The subsequent operation is the same as that at the end of vehicle use. As a result, the control circuit 13 enters a power saving state, and the storage circuit 57 enters the same state as when stopped.

  Since the voltage balance of the power storage element 1 is intermittently obtained in this way, the possibility of overvoltage of the power storage element 1 due to charging in a state where the voltage balance is lost at the start of the vehicle can be reduced, and high reliability is achieved. Is obtained.

  If an overdischarge of the storage element 1 is detected, the control circuit 13 transmits an overdischarge signal to the external control circuit 37 as in the first embodiment, and the reliability is ensured by stopping the voltage balance operation. ing.

  With the above configuration and operation, unnecessary discharge of the electricity storage device 1 during stoppage is suppressed as much as possible, and the intermittent voltage monitoring operation and voltage balancing operation are automatically performed to reduce the possibility of overvoltage and overdischarge. A power storage circuit with high reliability was realized.

  The second embodiment requires a power storage component 73, a selection switch power switch 79, and the like as compared with the first embodiment, and the configuration is slightly complicated. However, the control circuit 13 at the time of stop is similar to that of the first embodiment. Since the power saving state is maintained without being completely turned off, it is possible to start quickly by the start signal Wake.

  In the first and second embodiments, the power storage elements 1 are connected in series. However, this may be a series-parallel connection according to the required power specifications. A connection circuit diagram of the storage element 1 and the balance circuit 3 in this case is shown in FIGS.

  First, FIG. 3A shows a case where three storage elements 1 are connected in parallel to the balance circuit 3. In this case, the power storage elements 1 are connected in series and parallel as a whole, but the voltages across the three power storage elements 1 in the parallel connection portion thereof are equal, and therefore the balance circuit 3 needs to be connected to each power storage element 1. Instead, it may be connected to any one of the power storage elements 1 having the same voltage at both ends by parallel connection.

  Next, FIG. 3B shows a case where three storage elements 1 connected in parallel to the balance circuit 3 are connected in two stages in series. In this case, among the series-parallel connections of the entire storage element 1, the voltage across the storage element 1 is different at the series connection portion. However, if the storage element 1 has little variation, the variation width is small even when used in series connection. Therefore, it is not necessary to connect the balance circuit 3 to each power storage element 1. Therefore, as shown in FIG. 3B, for example, every six balance circuits 3 may be connected.

  Thus, the balance circuit 3 does not necessarily need to be connected to each power storage element 1, and the balance circuit 3 may be connected to each of the plurality of power storage elements 1 as a group.

  Moreover, although Embodiment 1 and 2 demonstrated the electrical storage circuit as an auxiliary power supply for vehicles as an example, it is applicable not only for vehicles but to a general emergency backup power supply.

  The power storage circuit according to the present invention can suppress unnecessary discharge of the power storage element at the time of stoppage and can obtain high reliability by preventing overvoltage and overdischarge, so that the power storage circuit for an auxiliary power supply for vehicles, an emergency backup power supply, etc. Useful.

1 is a block circuit diagram of a power storage circuit in Embodiment 1 of the present invention. The block circuit diagram of the electrical storage circuit in Embodiment 2 of this invention It is a connection circuit diagram of the electrical storage element of the electrical storage circuit in Embodiment 2 of this invention, (a) Connection circuit diagram when the electrical storage element is connected in parallel to the balance circuit, (b) Direct connection of the electrical storage element to the balance circuit Connection circuit diagram for parallel connection Schematic circuit diagram of conventional power storage circuit

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power storage element 2 Power storage element unit 3 Balance circuit 5 Switch means 7 Resistor 9 Voltage monitor selection switch 11 Balance circuit selection switch 13 Control circuit 19 Switch element 31 Insulation-type signal transmission means for starting 45 Insulation-type signal transmission for data transmission Means 51 Insulated signal transmission means for data reception 57 Power storage circuit 73 Power storage component 79 Power switch for selection switch

Claims (6)

A power storage element unit comprising a plurality of capacitor power storage elements that are charged and discharged with external power by a charge / discharge circuit provided outside, a balance circuit having switch means connected in parallel to the power storage elements, and A storage circuit comprising: a control circuit that detects voltage and controls on / off of the switch means; and a switch element that turns on / off power supply from the storage element unit to the control circuit ,
In a state in which charging / discharging of the external power is stopped, the control circuit turns off the switch element to stop the control circuit and turns off the switch means, and the switch according to an external start signal A second step in which the control circuit is activated by turning on the element and a third step in which the voltage balance of the power storage element is made constant by controlling the switch means are sequentially performed. An electricity storage circuit that returns to the first step and stops the control circuit until the activation signal is received to perform the second step and the third step . The control circuit controls the voltage balance to be constant via the voltage monitor selection switch and the balance circuit selection switch, and the switch element supplies power from the storage element unit to the voltage monitor selection switch and the balance circuit selection switch. The power storage circuit according to claim 1 which is turned on and off. The power storage circuit according to claim 2 , wherein the voltage monitor selection switch has a state in which a voltage at one end of any of the power storage elements is not selected. The power storage circuit according to claim 1, wherein reception of the activation signal from the outside is performed via an insulated signal transmission means. The power storage circuit according to claim 1, wherein the control circuit transmits an overdischarge signal when the voltage of the power storage element is overdischarged. 6. The power storage circuit according to claim 5, wherein transmission of the overdischarge signal is performed through an insulated signal transmission means.

Images