JP4072913B2 - Vehicle battery management device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply and accurately estimate the remaining capacity of a battery at a proper frequency. <P>SOLUTION: The estimation of a battery SOC of a battery management device 32 is outputted such that: in either of the case when a certain time is elapsed since former estimation, or the case when a vehicle travels a certain distance from the former estimation, and in the case when the operation state of the vehicle satisfies the condition that a vehicle speed is not lower than Vc and a throttle opening is not larger than &theta;c, a voltage to be set is set high by a previously set voltage value that is higher than a presently set voltage value set to an inverter device 11. At this time, a current value of a 36V battery 16 is measured, and a value of the battery SOC is estimated referring to a previously stored map by using the current value and an application voltage set by the inverter device 11. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  In particular, the present invention relates to a vehicle battery management apparatus for appropriately estimating the remaining capacity of a battery in a hybrid vehicle, an electric vehicle, or the like equipped with both an engine and an electric motor.

  In recent years, in vehicles such as automobiles, various types of hybrid vehicles using both an engine and a motor and electric vehicles that can run only by a motor have been developed and put into practical use from the viewpoint of low pollution and resource saving.

In such hybrid vehicles and electric vehicles, it is important to manage batteries with high accuracy. For example, in Japanese Patent Application Laid-Open No. 8-29506, the stop state of the vehicle is confirmed, the discharge current from the battery and the battery voltage at this time in the vehicle acceleration state immediately after that are detected, and from these discharge current and battery voltage There is disclosed a technique for calculating an internal resistance of a battery and accurately determining a remaining capacity of the battery based on the internal resistance.
JP-A-8-29506

  However, when trying to manage the battery with the remaining capacity of the battery as described in Patent Document 1 described above, complicated calculation processing using a plurality of parameters is required, and detection errors and calculation errors for each of these parameters are required. On the contrary, accurate battery management may be difficult.

  Incidentally, it is known that a lead battery used in a hybrid vehicle or the like has a smaller amount of current flowing when charged with the same voltage when the charge amount is large than when the charge amount is small. Therefore, there are vehicles that use this characteristic to estimate the current remaining battery capacity and perform battery management. Since the amount of current is small when the charging voltage is low, this estimation of the remaining battery capacity is often performed when the charging voltage is high, such as during regeneration, in order to accurately estimate the remaining battery capacity. Since it is not certain whether regeneration will be performed, there is a problem that the amount of charge becomes insufficient when the frequency of estimation is extremely low.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle battery management apparatus that can estimate the remaining capacity of a battery easily, accurately, and at an appropriate frequency. It is said.

  According to the present invention, in a vehicle battery management device that operates an inverter device connected to a generator based on a voltage value to be set to perform constant voltage charging on a battery, at least a preset time has elapsed since the previous estimation. A battery remaining capacity estimating means for estimating the battery remaining capacity in accordance with the applied voltage and the current value of the battery in this state. Yes.

  The vehicle battery management apparatus according to the present invention can estimate the remaining capacity of the battery easily, accurately, and at an appropriate frequency.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show an embodiment of the present invention, FIG. 1 is a schematic explanatory diagram of an entire vehicle having a vehicle battery management device, FIG. 2 is a flowchart of a battery remaining capacity estimation program, and FIG. It is a characteristic view which shows the relationship between an electric current and a battery remaining capacity.

  In FIG. 1, reference numeral 1 denotes an engine disposed in the front part of the vehicle, and driving force by the engine 1 is transmitted from an automatic transmission device (including a torque converter and the like) 2 behind the engine 1 to a transfer 3. .

  Further, the driving force transmitted to the transfer 3 is input to the rear wheel final reduction device 7 via the rear drive shaft 4, the propeller shaft 5, and the drive pinion shaft portion 6, while the reduction drive gear, the reduction driven gear, the front It is input to the front wheel final reduction gear (the front drive system is not shown) via the drive shaft.

  The driving force input to the rear wheel final reduction gear 7 is transmitted to the left rear wheel 9rl through the rear wheel left drive shaft 8rl and to the right rear wheel 9rr through the rear wheel right drive shaft 8rr. The driving force input to the front wheel final reduction gear is transmitted to the left front wheel 9fl via the front wheel left drive shaft 8fl and to the right front wheel 9fr via the front wheel right drive shaft 8fr.

Next, each electronics system mounted on this vehicle will be described.
This vehicle has two voltage systems of a 42V high voltage system and a 14V low voltage system.

  Reference numeral 11 denotes an inverter device. In the inverter device 11, the crank sprocket 12 of the engine 1 rotates the pulley 14 at the end of the rotating shaft via the belt 13 to generate electric power, and at the same time the power is not regenerated at the time other than the initial start-up. A motor / generator 15 for starting the engine 1 in starting or the like is electrically connected.

  The inverter device 11 is connected to a 42V system wiring connected to a chargeable / dischargeable 36V battery 16, and the 42V system wiring is connected to the starter motor 17 used only at the time of the first engine start, or the electric motor power. A steering device 18 and the like are connected.

  Further, a 42V system wiring is connected to the side surface of the inverter device 11, and a DC-DC converter 19 for converting a 42V voltage into a 14V voltage is provided substantially integrally therewith. A chargeable / dischargeable 12V battery 20 is connected to the wiring connected to the DC-DC converter 19, and other various lamps, audio, and a 14V load 21 such as each control device to be described later are connected.

  The vehicle is equipped with an idle stop control device 30 that executes automatic stop / restart control of the vehicle. The idle stop control device 30 includes an engine control device 31 that executes various well-known controls in the engine 1, In addition, a battery management device 32 for managing the charging state and discharging state of the 36V battery 16 is connected by, for example, a CAN (Controller Area Network) which is one of ISO standard protocols as a vehicle communication network.

  The idle stop control device 30 includes a brake pedal depression amount sensor 42 (which may detect brake hydraulic pressure) that detects a depression stroke of the brake pedal 41, and an accelerator pedal depression amount sensor 44 that detects a depression stroke of the accelerator pedal 43. It is connected. Further, the idle stop control device 30 includes a handle angle sensor 45 for detecting the handle angle θH, a vehicle speed sensor 46 for detecting the vehicle speed V, and selected shift positions (P, R, N, D, 3rd speed, 2nd speed, A shift position switch 47 for detecting each range position of the first speed, an engine speed sensor 48 for detecting the engine speed NE, and the like are connected.

  Then, the idle stop control device 30 determines whether or not a preset engine automatic stop condition is satisfied based on information obtained from these switches and sensors, and the engine automatic stop condition is satisfied. If the engine is in the idle state, a signal is output to the engine control device 31 to cause the engine 1 to stop automatically.

  Further, the idle stop control device 30 outputs a signal to the engine control device 31 and the inverter device 11 to drive the motor / generator 15 when the engine automatic stop condition is not satisfied in the idle stop state. 1 is restarted. Here, the engine automatic stop condition is, for example, that the brake pedal 41 is depressed, the accelerator pedal 43 is not depressed, and the shift position is P, N, D, 3rd speed, 2nd speed, 1st speed. This is a case where the vehicle speed V is substantially zero and there is no idle stop prohibition command from the battery management device 32.

  Further, the idle stop control device 30 is configured so that the regeneration condition set in advance (for example, the accelerator pedal 43 is not depressed, the engine speed NE is 1000 rpm or more, the vehicle speed V is 40 km / h or more, the drive system) And the engine 1 are connected and the fuel is not consumed), a regeneration command is output to the battery management device 32.

  Further, the battery management device 32 appropriately estimates the remaining capacity of the battery (battery SOC) according to the flowchart shown in FIG. 2 to be described later, and controls the temperature in the 36V battery 16 in order to manage the charge state and discharge state of the 36V battery 16. A battery temperature sensor 51 for detecting the voltage, a battery voltmeter 52 for detecting the voltage value of the 36V battery 16, a battery ammeter 53 for detecting the current value of the 36V battery 16, and a throttle opening sensor 49 for detecting the throttle opening. ing. The sensor value and the switch signal input to each control device described above are shared between these control devices by CAN communication.

  Specifically, the estimation of the battery SOC in the battery management device 32 is executed as follows. Either when a certain time (for example, 5 minutes) has elapsed since the previous estimation, or when traveling for a certain distance (for example, 2 km) since the previous estimation, and the driving state of the vehicle is the vehicle speed Vc (for example, 30 km / h) ) When the throttle opening satisfies the condition of θc (for example, 1.2 to 2 degrees) or less, a voltage value set in advance from the voltage value currently set for the inverter device 11 (for example, 2 It is output so that it is set to a voltage value higher by ~ 3V). Then, the current value of the 36V battery 16 at that time is measured, and the value of the battery SOC is estimated by referring to a map stored in advance with the current value and the applied voltage set by the inverter device 11. That is, the battery management device 32 has a function as a battery remaining capacity estimation unit.

  Further, when charging, the battery management device 32 outputs a target voltage value to the inverter device 11 without directly controlling the power generation torque of the motor / generator 15, and performs charging. Since the battery 16 is charged by regeneration or the like, the battery 16 is normally charged with a voltage value corresponding to a preset battery remaining capacity of 70%. When there is a regeneration command from the idle stop control device 30, a target voltage value slightly higher than normal is output to the inverter device 11.

  Further, when it is determined from the voltage value of the 36V battery 16 that the 36V battery 16 is in an overdischarged state, the battery management device 32 outputs an idle stop prohibition command to the idle stop control device 30. A rapid charging process is executed in which charging is performed at a voltage value that is higher than a predetermined charging voltage value to suppress the discharging state.

  Further, when it is determined from the current value of the 36V battery 16 that the 36V battery 16 is in an overcharged state, the battery management device 32 does not cut the power generation by the motor / generator 15 and sets the predetermined value above the normal charging voltage value. Charging suspension processing for setting a low voltage value is executed.

  Next, the battery remaining capacity estimation program in the battery management device 32 will be described with reference to the flowchart of FIG. First, in step (hereinafter, abbreviated as “S”) 101, parameters necessary for control are read, and the process proceeds to S102 to determine whether or not a fixed time (for example, 5 minutes) has elapsed since the previous estimation. If a predetermined time has elapsed since the previous estimation, the process jumps to S104, and if a predetermined time has not elapsed since the previous estimation, the process proceeds to S103.

  If the fixed time has not elapsed since the previous estimation and the process proceeds to S103, it is determined whether or not the vehicle travels a fixed distance (for example, 2 km) from the previous estimation. If the vehicle travels a certain distance (for example, 2 km) from the previous estimation, the process proceeds to S104. If the vehicle travels a certain distance from the previous estimation (that is, a certain time has not elapsed since the previous estimation, If the vehicle has not traveled a certain distance from the previous estimate), the program is exited.

  When the process proceeds from S102 or S103 to S104, whether or not the vehicle operating condition satisfies a condition that the vehicle speed is Vc (for example, 30 km / h) or more and the throttle opening is θc (for example, 1.2 to 2 degrees) or less. Is determined. This driving state is assumed in advance that the driver does not have an unnatural feeling even when the voltage value of the 36V battery 16 is increased and the 36V battery 16 is charged by the motor / generator 15 to generate deceleration acceleration. This is the operating state area that has been set.

  If the above operating condition is satisfied in S104, the process proceeds to S105. If not satisfied, the program is exited as it is.

  When the operation state of S104 is satisfied and the process proceeds to S105, the applied voltage is set so that the inverter device 11 is set to a voltage value that is higher by a preset voltage value (for example, 2 to 3 V) than the currently set voltage value. Output ascending command.

  Thereafter, the process proceeds to S106, the current value of the 36V battery 16 is measured, and the process proceeds to S107, where the current value of the 36V battery 16 measured in S106 and the applied voltage set by the inverter device 11 are stored in advance. The value of the battery SOC is estimated with reference to (an example is shown in FIG. 3).

  Then, the process proceeds to S108, the battery SOC estimated in S107 is output, and the program is exited.

  As described above, according to the present embodiment, the estimation of the battery SOC is to be executed when either a certain time has elapsed since the previous estimation or when the vehicle travels a certain distance from the previous estimation. Even if the regenerative state is not reached, it is possible to increase the applied voltage to increase the current value to the 36V battery 16 and accurately estimate the battery SOC.

  In addition, even if either a certain time has elapsed since the previous estimation or a certain distance of travel has been established since the previous estimation, the application of the applied voltage can be reduced by further limiting the battery SOC estimation depending on the driving state of the vehicle. The system is highly practical because it causes deceleration acceleration due to ascending and the driver does not feel unnatural.

  Furthermore, according to the present embodiment, it is possible to accurately estimate the battery SOC from the applied voltage and the current value to the 36V battery 16 simply.

  Depending on the specification of the vehicle, the following vehicle is considered for the estimation of the battery SOC and the processing of S102, S103, and S104.

  1. It is determined whether or not the vehicle having only S102, that is, whether or not a certain time has elapsed since the previous estimation. If the certain time has elapsed since the previous estimation, the process proceeds to S105, and the certain time has not elapsed since the previous estimation. If so, exit the program.

  2. If the vehicle having S102 and S104, that is, a certain time has passed since the previous estimation and the driving state of the vehicle of S104 is satisfied, the process proceeds to S105, and if either of S102 or S104 is not satisfied Exit the program.

  3. It is determined whether or not the vehicle has only S103, that is, whether or not the vehicle has traveled a fixed distance from the previous estimation. If so, exit the program.

  4). If the vehicle having S103 and S104, that is, traveling a certain distance from the previous estimation and satisfying the driving condition of S104, the process proceeds to S105, and if either of S103 or S104 is not satisfied Exit the program.

  5. If the vehicle has S102 and S103, that is, if a certain time has passed since the previous estimation, or if it has traveled a certain distance from the previous estimation, the process proceeds to S105, and if neither S102 nor S103 is satisfied, the program Exit.

  Further, the order of determination in S102 and S103 may be reversed, and the process in S104 may be performed before S102 and S103.

Schematic explanatory diagram of an entire vehicle having a vehicle battery management device Battery remaining capacity estimation program flowchart Characteristic diagram showing the relationship between applied voltage, battery current and remaining battery capacity

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 11 Inverter apparatus 15 Motor / generator 16 36V battery 30 Idle stop control apparatus 31 Engine control apparatus 32 Battery management apparatus (battery remaining capacity estimation means)
46 Vehicle speed sensor 49 Throttle opening sensor 53 Battery ammeter
Agent Patent Attorney Susumu Ito

Claims (4)

In a battery management device for a vehicle that operates an inverter device connected to a generator based on a voltage value to be set and performs constant voltage charging on the battery,
At least when a preset time has elapsed since the previous estimation, the voltage value to be set is increased and set, and the remaining battery capacity is estimated according to the applied voltage and the current value of the battery in this state. A battery management apparatus for a vehicle comprising battery remaining capacity estimation means. In a battery management device for a vehicle that operates an inverter device connected to a generator based on a voltage value to be set and performs constant voltage charging on the battery,
At least when the vehicle travels a predetermined distance from the previous estimation, the voltage value to be set is increased and set, and the remaining battery capacity is estimated according to the applied voltage and the current value of the battery in this state. A battery management apparatus for a vehicle comprising battery remaining capacity estimation means. In a battery management device for a vehicle that operates an inverter device connected to a generator based on a voltage value to be set and performs constant voltage charging on the battery,
When at least one of the case where a preset time has elapsed from the previous estimation and the case where the vehicle travels a preset distance from the previous estimation is satisfied, the voltage value to be set is increased and set, and the applied voltage And a battery remaining capacity estimating means for estimating the remaining battery capacity according to the current value of the battery in this state.   The estimation of the remaining battery capacity is further executed only when the driving condition of the vehicle satisfies a preset driving condition. Vehicle battery management device.

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