JP2009240081A - Controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller capable of detecting a voltage and load on a battery pack side or a voltage on a charge/discharge apparatus side without correcting variations in voltage detection. <P>SOLUTION: A power supply part of a hybrid vehicle includes: the battery pack 100; an inverter 102 as the load or the charge/discharge apparatus; and a controller 101 that detects the voltage of the battery pack 100 and the voltage of the inverter 102, and the battery pack 100 and the inverter 102 are connected via relays 1 to 3. In the control part 101, variation correction in the detection is eliminated since a voltage sensor 103 for detecting the voltage on the battery pack 100 side and the inverter 102 side is used in common, and the voltage at different positions can be detected by the voltage sensor having the same characteristics. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device, and more particularly to a control device for a battery pack connected to a load or a charge / discharge device via a switch that cuts off and conducts current.

  For example, in an assembled battery (secondary battery) used as a power source for driving a load such as an inverter of a hybrid vehicle or an electric vehicle, a function of detecting the voltage of the assembled battery and the load during charge / discharge operation is indispensable. . Since such an assembled battery has a high voltage, the assembled battery is connected to a load via a switch (for example, a relay) that cuts off and conducts current.

  In this type of control device, a voltage sensor for detecting a voltage is provided on each of the assembled battery and the load (or charge / discharge device) side (see, for example, Patent Document 1). In addition, when charge / discharge operation is performed between an assembled battery and a load, it is indispensable to perform control while comparing and referring to the voltage of the assembled battery and the voltage of the load. For this purpose, an accurate voltage sensor is required. In addition, a method of correcting the difference in the characteristics of the voltage sensors of the assembled battery and the load is applied (for example, see Patent Document 2).

JP 2006-333893 A JP 2006-115643 A

  However, in the conventional system, in order to detect the voltage on the assembled battery side and the voltage on the load side, a dedicated voltage sensor is provided on each of the assembled battery and the load side. The detection characteristics vary depending on the installation environment, and control must be performed while correcting the detected voltage value. In addition, since the assembled battery and the voltage sensor on the load side are separate, the cost increases, and the area occupied by the number of voltage sensors also increases in terms of structure.

  An object of the present invention is to provide a control device capable of detecting a voltage on an assembled battery side and a load or a voltage on a charge / discharge device side without correcting variations.

  In order to solve the above-described problems, the present invention provides a control device for an assembled battery connected to a load or a charge / discharge device via a switch that cuts off and conducts current, and the voltage on the assembled battery side and the load or charge / discharge A voltage sensor for detecting the voltage on the device side is shared.

  In the present invention, it is preferable to include a switching circuit for switching the input of the voltage sensor between the assembled battery side and the load or charging / discharging device side, and the switching circuit includes a voltage on the assembled battery side and a voltage on the load or charging / discharging device side. It is more preferable to prevent simultaneous input to the voltage sensor. Further, it is further preferable that the switching circuit controls so that the input of the voltage sensor is not connected to the assembled battery side or the load or charge / discharge device side for a predetermined time before and after the switch transits to the on state or the off state.

  According to the present invention, since the voltage sensor for detecting the voltage on the assembled battery side and the voltage on the load or charging / discharging device side is shared, the voltage at different locations can be detected by the voltage sensor having the same characteristics. It is possible to obtain an effect that the voltage on the assembled battery side and the voltage on the load or charge / discharge device side can be detected without correcting the above.

  Hereinafter, an embodiment in which the present invention is applied to a control device for a power source unit of a hybrid vehicle will be described with reference to the drawings.

(Constitution)
As shown in FIG. 1, the power supply unit of the hybrid vehicle is roughly divided into an assembled battery 100, an inverter 102 as a charge / discharge device, and a control device 101 that detects the voltage of the assembled battery 100 and the voltage of the inverter 102. The assembled battery 100 and the inverter 102 are connected via a relay as a switch.

  In the present embodiment, the assembled battery 100 is configured by connecting 96 unit cells 106 (lithium ion batteries in this embodiment) having a rated voltage of 3.6 V in series, and the rated total voltage of the assembled battery 100 is 345. 6V. Specifically, the unit cells 106 are grouped in units of a plurality (for example, four) to form an assembled battery, and the plurality of assembled batteries are fixed in a battery box and connected in series, so that vibration resistance when mounted on a vehicle is obtained. In addition to securing the structure, it ensures convenience in manufacturing and assembly.

  The inverter 102 generates AC power of a motor of a hybrid vehicle driven by three-phase AC from DC power of the assembled battery 100, and has a large capacity (about 2000 μF) smoothing connected between both terminals of the assembled battery 100. A capacitor 5 is incorporated. As the smoothing capacitor 5, for example, an electrolytic capacitor or a film capacitor can be used. The inverter 102 conducts conduction and interruption at high speed, and performs power conversion between DC power and AC power. At this time, since a large current is interrupted at a high speed, a large voltage fluctuation occurs due to the inductance of the DC circuit. The smoothing capacitor 5 is provided to suppress this voltage fluctuation.

  A relay is interposed between the assembled battery 100 and the inverter 102. In other words, the assembled battery 100 side and the inverter 102 side (charge / discharge device side) are defined by the relay. That is, the minus terminal of the assembled battery 100 is connected to the minus terminal of the inverter 102 via the relay 3, and the plus terminal of the assembled battery 100 is connected to the plus terminal of the inverter 102 via the relay 2. In addition, the relay 2 includes a resistor 4 for suppressing a large current inrush that occurs when the initial power is supplied from the assembled battery 100 to the inverter 102 (during precharge operation), and a connection from the assembled battery 100 to the inverter 102. A series circuit with a precharging relay 1 for charging the smoothing capacitor 5 at the time of initial power supply is connected in parallel.

  The control device 101 includes a switching circuit 105 that switches a detection position of the voltage on the assembled battery 100 side and the voltage on the inverter 102 side, and a voltage sensor 103 that detects the voltage on the assembled battery 100 side or the inverter 102 side switched by the switching circuit 105. And a control circuit 104 that controls ON / OFF of the relays 1 to 3. The control device 101 includes a voltage sensor for detecting the voltage of each unit cell 106 constituting the assembled battery 100, a temperature sensor for detecting the temperature of the assembled battery 100, and a voltage between the assembled battery 100 and the inverter 102. An I / O device having functions such as a current sensor for detecting current and an A / D converter for taking in an output from these sensors is also provided, but these are omitted in FIG.

  FIG. 2 shows details of the switching circuit 105. As shown in FIG. 2, the switching circuit 105 includes optical insulating elements 8 and 9 for taking in the voltage on the assembled battery 100 side into the voltage sensor 103, and an optical insulating element for taking in the voltage on the inverter 102 side into the voltage sensor 103. 10 and 11 and the photoinsulating elements 8 and 9 on the assembled battery 100 side and the photoinsulating elements 10 and 11 on the inverter 102 side are alternately switched on / off in order to take in the voltage on the assembled battery 100 side or the inverter 102 side. The change-over switches 12 and 13 composed of NPN transistors for control, the resistor 6 connected to the collector of the NPN transistor of the change-over switches 12 and 13 (the primary side of each optical insulating element), and the change-over switches 12 and 13 An I / O device 108 for controlling the NPN transistor and the bases of the NPN transistors of the changeover switches 12 and 13 and AND circuit 14 for controlling not to take in the voltages on the 00 side and the inverter 102 side at the same time, that is, for controlling so that the optical insulating elements 8 and 9 and the optical insulating elements 10 and 11 are not simultaneously turned on. And the protection circuit 107 composed of the PNP transistor 15 and the I / O device 108 immediately after startup (immediately after the I / O device 108 is turned on), the control by the software becomes invalid and the I / O device 108 In order to prevent the changeover switch 12 of the optical isolation elements 8 and 9 and the changeover switch 13 of the optical isolation elements 10 and 11 from being simultaneously turned on in the case of runaway, And a pull-down resistor 7 connected to the ground. The ground is at the same potential as the chassis of the hybrid vehicle.

  With this circuit configuration, the photoinsulating elements 8 to 11 are protected from being damaged by the photoinsulating elements 8 to 11 without being a large current path between the assembled battery 100 and the inverter 102. The circuit configuration is such that one voltage sensor 103 detects the voltage on the 100 side and the inverter 102 side. Note that the control circuits of the relays 1 to 3 are also controlled by the I / O device 108 using an interface element such as a field effect transistor.

(Operation)
Next, the operation of the control device 101 of this embodiment will be described.

<Operation during initial power supply>
As shown in FIG. 3, in the high impedance state (208) in which the optical insulating elements 8 to 11 are all OFF, the relay 3 is turned on to connect the assembled battery 100 and the negative side of the inverter 102 (201). The insulating elements 8 and 9 are turned on (202), the voltage on the assembled battery 100 side is captured and detected, and after the processing on the assembled battery 100 side is finished, the optical insulating elements 8 and 9 are turned off and the high impedance state ( 209).

  Next, in order to turn on the initial power to the inverter 102 (precharge operation), the relay 1 is turned on and connected (203), and then the optical insulating elements 10 and 11 are turned on (204). After the voltage is captured and detected, and it is confirmed that the voltage on the inverter 102 side has reached about 90% or more of the voltage value on the assembled battery 100 side, the opto-insulating elements 10 and 11 are turned off to return to the high impedance state. (211). Next, the relay 2 is turned on (205), the positive electrode side is connected, and then the relay 1 is turned off to release the connection (206), and the initial power-on is completed. By performing such control during the initial power supply, the relays 2 and 3 can be protected against damage due to a large current, and the safety of the inverter 102 can be maintained. Note that the relay 1 is controlled to be turned on only when the initial power is supplied.

<Normal operation>
Thereafter, the photoinsulating elements 8 and 9 are turned on (207), and the routine proceeds to a steady operation for taking in the voltage on the assembled battery 100 side and monitoring the state of the assembled battery 100.

  The period of the white arrow shown in FIG. 3 (predetermined time before and after the relays 1 to 3 are switched to the on state or the off state) is the surge voltage accompanying the on and off of the relays 1 to 3 and chattering to the optical insulating elements 8 to 11. In these periods, the input of the voltage sensor 103 is not connected to either the assembled battery 100 side or the inverter 102 side.

(Effects etc.)
Next, functions, effects, and the like of the control device 101 of this embodiment will be described.

  In the control device 101 of the present embodiment, the voltage sensor 103 for detecting the voltage on the assembled battery 100 side and the voltage on the inverter 102 side is shared, so that voltages at different locations can be detected by voltage sensors having the same characteristics. The voltage on the assembled battery 100 side and the inverter 102 side can be detected without correcting the variation. In addition, since the voltage sensors are shared (reduced) as compared with the prior art, the cost can be reduced and the area occupied by the voltage sensors can be reduced, that is, the size can be reduced.

  In the control device 101 of the present embodiment, as described above, the input of the voltage sensor 103 is not connected to either the assembled battery 100 side or the inverter 102 side during the period of the white arrow shown in FIG. It is possible to protect the voltage sensor 103 and the switching circuit 105 by eliminating a surge voltage caused by turning on and off of 3 and a burden caused by chattering on the optical insulating elements 8 to 11.

  Furthermore, in the control apparatus 101 of this embodiment, since the voltage of the assembled battery 100 is insulated by the photoinsulating elements 8 to 11, there is a possibility that an electric shock may occur even if a passenger touches the chassis (the same potential as the ground) of the hybrid vehicle. Absent.

  In the present embodiment, the inverter 102 is exemplified as a load or a charge / discharge device. However, the inverter 102 converts the regenerative power (three-phase AC of the motor) into a direct current when the hybrid vehicle is braked. Charge. For this reason, the inverter 102 functions as a charge / discharge device, but the present invention can also be applied to a device that does not have such a charging function and functions only as a load of the assembled battery 100. In this embodiment, a relay is exemplified as a switch. However, the present invention is not limited to this, and for example, a switch element such as a power FET may be used.

  Furthermore, in the present embodiment, the I / O device 108 is illustrated, but the present invention is not limited to this, and may be configured by, for example, a microcomputer. At that time, the microcomputer may incorporate an A / D converter or the like.

  In the present embodiment, an example in which the present invention is applied to a control device for a power supply unit of a hybrid vehicle has been described. For example, the present invention can be applied to a stationary power storage system. Furthermore, such a power storage system may store, for example, power generated by solar thermal power generation or wind power generation. Moreover, although the lithium ion battery was illustrated as the single battery which comprises an assembled battery in this embodiment, this invention is not restrict | limited to this. For example, a nickel metal hydride battery or the like may be used.

  Since the present invention provides a control device that can detect the voltage on the assembled battery side and the voltage on the load or charge / discharge equipment side without correcting variations, it contributes to the manufacture and sale of the control device. With the above applicability.

It is a circuit diagram of a control device of an embodiment to which the present invention is applicable. It is a circuit diagram which shows the detail of the switching circuit of the control apparatus of embodiment. It is a timing chart which shows the ON / OFF state of a relay and an optical insulation element.

Explanation of symbols

1, 2, 3 Relay (switch)
100 assembled battery 101 control device 102 inverter (load or charge / discharge equipment)
103 Voltage sensor 105 switching circuit

Claims (4)

  A voltage sensor for detecting a voltage on the assembled battery side and a voltage on the load or charge / discharge equipment side in a control apparatus for the assembled battery connected to the load or charge / discharge equipment via a switch that cuts off and conducts current A control device characterized by the common use.   The control device according to claim 1, further comprising a switching circuit that switches an input of the voltage sensor between the assembled battery side and the load or charge / discharge device side.   The control device according to claim 2, wherein the switching circuit prevents the voltage on the assembled battery side and the voltage on the load or charge / discharge device side from being simultaneously input to the voltage sensor.   The switching circuit controls the input of the voltage sensor not to be connected to the assembled battery side or the load or charge / discharge device side for a predetermined time before and after the switch transitions to an on state or an off state. The control device according to claim 2 or 3.

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