JP2017093070A - Power source system for vehicle - Google Patents

Abstract

A power supply system for a vehicle is provided that can prevent the auxiliary battery from rising even when the discharge amount of the auxiliary battery increases.
[Solution]
The vehicle power supply system 10 includes an auxiliary battery 21 that supplies electric power to the auxiliary machines 12, 33, 41, 51, and 52 of the vehicle, a main battery 31 that supplies electric power to the drive motor of the vehicle, The power converter 42 charges the auxiliary battery by reducing the voltage supplied from the main battery, and the auxiliary battery is charged in a predetermined charging state by operating the power converter while the vehicle is parked. Control units 51 and 52 to be executed, wherein the control unit determines that the discharge state of the auxiliary battery is in a predetermined discharge state when the discharge amount of the auxiliary battery is larger than a predetermined value, and the determination And charging execution units 51 and 52 for executing the charging by the power conversion device while the vehicle is parked when the vehicle is determined to be in the predetermined discharge state.
[Selection] Figure 1

Description

  The present invention relates to a vehicle having a main battery and an auxiliary battery that supply electric power to a drive motor, and more particularly to a power supply system that charges an auxiliary battery with electric power from the main battery.

Conventionally, during parking, when the parking time (IG off time) measured by the timer IC has passed a predetermined time, the microcomputer is activated, and the auxiliary battery storage (SOC: State of Charge) is below a predetermined value In addition, a charging control is proposed in which a power supply system is started and a main battery is charged to an auxiliary battery by a DC / DC converter (Patent Document 1). In Patent Document 1, further, the auxiliary battery is charged when the storage amount of the main battery is equal to or greater than a predetermined value, and the charging is stopped when the storage amount of the main battery is equal to or less than the predetermined value.
On the other hand, when the power supply system is activated by the timer IC during parking, if the auxiliary battery's dark current (discharge current when the system is off) is greater than a predetermined value, it is determined that there is an abnormality and the auxiliary battery is compensated. Some devices stop charging the battery (Patent Document 2).

Japanese Patent No. 4218634 JP 2014-140268 A

  However, as disclosed in Patent Document 2, when the discharge amount of the auxiliary battery increases due to an abnormality such as an increase in dark current, the auxiliary battery may be raised earlier if charging of the auxiliary battery is stopped. . In addition, if an abnormality occurs during charging of the auxiliary battery, charging is stopped halfway, and the auxiliary battery may be raised earlier. Depending on the type of abnormality, it is preferable to complete the charging instead of interrupting the charging in the middle.

  The present invention has been made in view of such circumstances, and a main object of the present invention is to provide a power source for a vehicle that can suppress an early rise in the auxiliary battery even when the discharge amount of the auxiliary battery increases. To provide a system. By restraining the auxiliary battery from rising early, the burden on the user is reduced, for example, by delaying the time until the vehicle cannot start due to the auxiliary battery running out.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The present invention is a power supply system for a vehicle, wherein an auxiliary battery that supplies electric power to an auxiliary machine of the vehicle, a main battery that supplies electric power to a drive motor of the vehicle, and electric power supplied from the main battery And a control unit that operates the power conversion device while the vehicle is parked to charge the auxiliary battery in a predetermined charging state. The control unit determines that the discharge state of the auxiliary battery is a predetermined discharge state when the discharge amount of the auxiliary battery is larger than a predetermined value; and the control unit determines that the predetermined discharge state is determined by the determination unit. And a charging execution unit that causes the power conversion device to execute the charging while the vehicle is parked.

  According to the said structure, electric power is supplied to the auxiliary machine of a vehicle with an auxiliary machine battery. Further, the determination unit determines that the discharge amount of the auxiliary battery is in a predetermined discharge state larger than a predetermined value. And when it determines with it being a predetermined discharge state by the determination part, a control part performs the charge from a main battery to an auxiliary battery in a predetermined charge state by a power converter device during parking of a vehicle. For this reason, even if it is a case where the discharge amount of an auxiliary machine battery increases, it can suppress that the electrical storage amount of an auxiliary machine battery reduces, and the rise of an auxiliary machine battery can be suppressed.

  In addition, the present invention is a power supply system for a vehicle, and is supplied from an auxiliary battery that supplies electric power to an auxiliary device of the vehicle, a main battery that supplies electric power to a driving motor of the vehicle, and the main battery. A power conversion device that steps down the power to charge the auxiliary battery, and a control unit that, when a predetermined condition is satisfied while the vehicle is parked, causes the power conversion device to perform the charging in a predetermined charging state; The control unit is determined to be in a predetermined discharge state when the discharge amount of the auxiliary battery is larger than a predetermined value, and determined to be in the predetermined discharge state by the determination unit A charging execution unit that changes the predetermined charging state in the charging.

  According to the said structure, electric power is supplied to the auxiliary machine of a vehicle with an auxiliary machine battery. Further, when a predetermined condition is satisfied while the vehicle is parked, the control unit causes the power converter to charge the main battery from the main battery in a predetermined charging state. Here, the determination unit determines that the discharge amount of the auxiliary battery is in a predetermined discharge state larger than a predetermined value. And when it determines with a predetermined discharge state by the determination part, a control part changes the predetermined charge state in charge, for example so that the charge amount to an auxiliary machine battery may be increased, and performs charge. As a result, even when the discharge amount of the auxiliary battery increases, it is possible to suppress a decrease in the charged amount of the auxiliary battery, and it is possible to suppress the rise of the auxiliary battery. Also, in order to continue charging the auxiliary battery while suppressing the temperature rise of the equipment, wiring and auxiliary battery at the time of charging, change the charging to the auxiliary battery, for example, to reduce the charge. Sometimes it is done. Thereby, charging can be continued and the rise of the auxiliary battery can be suppressed while suppressing the temperature rise of the equipment, wiring, and auxiliary battery during charging.

The schematic diagram which shows a power supply system and a periphery structure. The flowchart which shows the start instruction | indication of auxiliary machine battery charge during parking. The flowchart which shows execution of auxiliary machine battery charge during parking. The time chart which shows the operation | movement at the time of ON state adhering of relay IGB. The flowchart which shows execution of auxiliary machine battery charge in the predetermined discharge state in 1st Embodiment. The flowchart which shows determination of being in a predetermined discharge state. The flowchart which shows the change of the auxiliary machine battery charge control in 2nd Embodiment. The schematic diagram which shows the example of a change of a power supply system.

(First embodiment)
The first embodiment will be described below.

  As shown in FIG. 1, the hybrid vehicle includes a power supply system 10, a motor generator 11, an engine (not shown), a load 12 such as an auxiliary machine, and the like. A thin solid line indicates a low-voltage electrical wiring, a thick solid line indicates a high-voltage electrical wiring, and a dotted line indicates a communication line. The vehicle travels using the motor generator 11 and the engine as drive sources. The motor generator 11 functions as an electric motor and a generator. The load 12 is various devices mounted on the vehicle, and includes a load driven by the driving force of the engine and a load driven by the battery power.

  The power supply system 10 includes an auxiliary battery 21, a main battery 31, a Bat-ECU 33, a PCU (Power Control Unit) 41, a DC / DC converter 42, an HV-ECU 51, a verification ECU 52, and the like.

  The auxiliary battery 21 is a secondary battery such as a lead battery. The auxiliary battery 21 supplies power to auxiliary machines such as the load 12, Bat-ECU 33, PCU 41, HV-ECU 51, and verification ECU 52. Auxiliary battery 21 is charged with power supplied by DC / DC converter 42 (power conversion device) by stepping down power from the main battery or high voltage system. The sensor 22 detects the state of the auxiliary battery 21. The sensor 22 (voltage sensor, current sensor, temperature sensor) detects the voltage of the auxiliary battery 21, the current input / output to / from the auxiliary battery 21, and the temperature of the auxiliary battery 21, and detects these detected values as HV−. It transmits to ECU51. When the charged amount of auxiliary battery 21 falls below the lower limit amount, each ECU becomes inoperable and power supply system 10 (vehicle) becomes inoperable.

  The main battery 31 is a high-capacity secondary battery such as a lithium ion battery, supplies power to the PCU 41, and is used as a power source for the drive motor 11. The main battery 31 is charged with electric power supplied from the PCU 41. The sensor 32 detects the state of the main battery 31. A sensor 32 (voltage sensor, current sensor, temperature sensor) detects the voltage, current, and temperature of the main battery 31 and transmits the detected values to the Bat-ECU 33. The Bat-ECU 33 monitors the state of the main battery 31. The Bat-ECU 33 calculates the amount of electricity stored in the main battery 31 based on the detected values of the voltage, current, temperature, etc. of the main battery 31 and transmits the calculation result to the HV-ECU 51.

  The PCU 41 includes a DC / DC converter 42, a boost converter 43, an inverter 44, an MG-ECU 45, and the like.

  The DC / DC converter 42 is connected between the auxiliary battery 21 and the main battery 31. The DC / DC converter 42 steps down (converts) the electric power input from the main battery 31 and outputs it to the auxiliary battery 21. The DC / DC converter 42 and the main battery 31 are connected via a system main relay (SMR) 58. The system main relay 58 connects and disconnects the DC / DC converter 42 and the main battery 31.

  Boost converter 43 is connected to main battery 31 and DC / DC converter 42. Boost converter 43 boosts (converts) the electric power input from main battery 31 and outputs it to inverter 44. The step-up converter 43 steps down (converts) the electric power input from the inverter 44 and outputs it to the DC / DC converter 42 and the main battery 31.

  Inverter 44 is connected between motor generator 11 and boost converter 43. Inverter 44 converts AC power generated by motor generator 11 into DC power using the driving force of the engine, and outputs the converted DC power to boost converter 43. Inverter 44 converts the DC power input from boost converter 43 into AC power, and outputs the converted AC power to motor generator 11.

  The MG-ECU 45 controls the DC / DC converter 42, the boost converter 43, and the inverter 44 under the control of the HV-ECU 51.

  Each ECU (33, 45, 51) of the power supply system such as the HV-ECU 51 is connected to the auxiliary battery 21 via the wiring 55 including the relay IGCT, and the relay IGCT connects and disconnects them.

  The HV-ECU 51 is connected to the auxiliary battery via a wiring 56 (normal start signal line) including the relay IG2, and the relay IG2 connects and disconnects them.

  The start switch 53 is a switch for the user to start and stop the power supply system 10 (vehicle). The user outputs a command to the verification ECU 52 by turning on or off the start switch 53.

  The verification ECU 52 determines whether or not a signal from a remote key (not shown) is checked against the vehicle. When there is an activation command by the activation switch in a state where the vehicle has been verified, the verification ECU 52 controls the relay IG2 to be in an on state (connection state) (connection command is on) and sets the relay IGB to an off state (disconnection state). Control (connection command off). Thereby, electric power is supplied from the auxiliary battery 21 to the HV-ECU 51, and the HV-ECU 51 is activated.

  The HV-ECU 51 is connected to the auxiliary battery via a wiring 54 (a parking start signal line) including the relay IGB, and the relay IGB connects and disconnects them.

  The control state (connection command ON or OFF) of the relay IG2 and the relay IGB is transmitted from the verification ECU 52 to the HV-ECU 51 after the communication device is activated in order to detect abnormality of the relay IG2 and the relay IGB.

  When a predetermined time elapses after the start switch 53 is turned off and the power supply system 10 is stopped, the verification ECU 52 instructs the auxiliary battery 21 to start charging from the main battery 31 and the auxiliary battery in the parked state. Charging is performed.

  FIG. 2 is a flowchart showing an instruction to start charging the auxiliary battery while parking. This series of processing is repeatedly executed at a predetermined cycle by the verification ECU 52 when the start switch 53 is turned off.

  First, it is determined whether the parking time has passed a predetermined time (S11). Specifically, it is determined whether or not the elapsed time since the start switch 53 is turned off has passed a predetermined time for determining that the auxiliary battery 21 may rise. If it is determined that the parking time has passed the predetermined time (S11: YES), the relay IGB is controlled to be in an on state (connected state) (connection command is on), and the relay IG2 is controlled to be in an off state (disconnected state) ( The connection command is turned off) (S12), and this series of processing ends. On the other hand, in the determination of S11, when it is determined that the parking time has not passed the predetermined time (S11: NO), this series of processes is terminated as it is. Then, when relay IGB is turned on, power is supplied from auxiliary battery 21 to HV-ECU 51 via a wiring including relay IGB as an activation signal, and HV-ECU 51 is activated.

  The HV-ECU 51 controls the relay IGCT to be turned on when an activation signal is input from at least one of the wiring 54 including the relay IGB and the wiring 56 including the relay IG2 (when the output is on). When relay IGCT is turned on, power is supplied from the auxiliary battery to each ECU (33, 45, 51) of the power supply system via wiring 55, each ECU is started, and communication between the ECUs is started. To do. Then, after performing a system check, the system main relay 58 is connected, and the HV-ECU 51 instructs the DC / DC converter to charge the auxiliary battery.

  FIG. 3 is a flowchart showing execution of auxiliary battery charging during parking. This series of processing is executed by the HV-ECU 51 when the HV-ECU 51 is activated.

  When it is determined that relay IGB is in the on state and relay IG2 is in the off state (S21: YES), relay IGCT is connected to supply power from the auxiliary battery to each ECU of the power supply system. Start up (S22). Subsequently, it is confirmed whether the power supply system 10 is normal (S23). Next, if the power supply system 10 is normal (S23: YES), the state of the auxiliary battery 21 and the main battery 31 is confirmed. First, when the storage amount (SOC) of the auxiliary battery 21 is equal to or less than a predetermined value (S24: YES), it is determined that the auxiliary battery 21 needs to be charged. And if the main battery 31 has the charge amount at the time of charging the auxiliary machine battery 21 (S25: YES), it will determine with it being in the state which can be charged. Finally, if the condition is satisfied (S25: YES), the system main relay (SMR) 58 is connected (S26), and the auxiliary battery 21 is charged (S27).

  After the auxiliary battery is charged, the power of the main battery 31 is stepped down by the DC / DC converter 42 until the storage amount of the auxiliary battery 21 reaches a predetermined amount with the target voltage set as a target. Charge. The amount of electricity stored in the auxiliary battery 21 is calculated based on the detection value of the sensor 22 that detects the state of the auxiliary battery 21. For example, when the auxiliary battery 21 is a lead battery, the charged amount is estimated based on the characteristic that the acceptability of the charging current is reduced near the full charge. Thereafter, the HV-ECU 51 stops the power supply system by turning off the SMR 58, and communicates the completion of charging from the HV-ECU 51 to the verification ECU 52. The control ECU 52 controls the relay IGB to be turned off, and the HV-ECU 51 controls the relay IGCT to be turned off, thereby completing the charging. The charging is also terminated when the charging execution time has exceeded a predetermined timeout time. On the other hand, when a negative determination is made in any of the above-described processes of S21 to S27, this series of processes is terminated without executing charging.

  Here, during startup, for example, the relay IGB may be stuck in an on state. The state in which relay IGB is fixed in the on state is a state in which electric power is supplied from auxiliary battery 21 to HV-ECU 51, and corresponds to a state in which the discharge amount of auxiliary battery 21 has increased. For this reason, if the state where the relay IGB is fixed while the vehicle is parked is continued, the auxiliary battery 21 may continue to be discharged and the auxiliary battery 21 may be raised. The same problem occurs when the relay IG2 and the relay IGCT are fixed in the on state.

  FIG. 4 is a time chart showing the operation when the relay IGB is fixed in the ON state.

  When the parking time elapses at the time t1, the relay IGB is controlled to be in an on state, and the output via the relay IGB is in an on state. In response to this, the HV-ECU 51 is activated to perform charging, and the relay IGCT is turned on. Then, charging is performed.

  At time t2, when the output of relay IGB is fixed in the on state, at least the state in which electric power is supplied from auxiliary battery 21 to HV-ECU 51 will continue.

  When the time-out time for charging the auxiliary battery 21 has elapsed at time t3, the relay IGB is controlled to be in the off state. However, since the output of the relay IGB is fixed in the on state, the collation ECU 52 remains in the on state even though the verification ECU 52 controls the relay IGB in the off state.

  Since the relay IGB is fixed in the on state at time t4, the verification ECU 52 determines that the output through the relay IGB remains in the on state even though the verification ECU 52 controls the relay IGB in the off state. Judged as on-sticking abnormality. If parking continues in a discharged state of the auxiliary battery 21 due to this abnormality, there is a possibility that the auxiliary battery will eventually rise. When the auxiliary battery runs out, the abnormality information in the volatile memory of the HV-EUC 51 is lost. To prevent this, the abnormality information is stored in the non-volatile memory.

  At time t5, as a result of power being continuously supplied from at least the auxiliary battery 21 to the HV-ECU 51, the auxiliary battery may increase after long-term parking. At time t6, the auxiliary battery 21 is replaced by service, and the HV-ECU 51 is started by turning on the start switch 53 after replacement. Accordingly, the contents of the abnormality information such as the IGB on fixing abnormality are confirmed, and the verification ECU 52 and the like are exchanged.

  In the present embodiment, in order to suppress the rise of the auxiliary battery 21, in this embodiment, when the HV-ECU 51 determines that the discharge amount of the auxiliary battery 21 is in a predetermined discharge state larger than a predetermined value, the auxiliary battery 21 The charging of was to be executed.

Examples of the predetermined discharge state include the following states. In any case, the discharge amount of the auxiliary battery 21 is increased, and if the auxiliary battery 21 is not charged, there is a risk that the auxiliary battery will rise later.
-When the start signal line is stuck on abnormally: The relay IGB / relay IG2 / relay IGCT is stuck on abnormally.
-When the auxiliary relay that is supplied with power from the auxiliary battery via the relay is stuck on abnormally: Main battery cooling fan / engine cooling fan / external discharge relay.
• When fail-safe operation is performed to continue driving the auxiliary equipment during parking due to an abnormality: Fail-safe operation to continue driving the main battery cooling fan and engine cooling fan during parking.
・ When the number of auxiliary equipment driven during parking increases: Increase in dark current, external discharge, communication, etc.

  FIG. 5 is a flowchart showing execution of auxiliary battery charging in a predetermined discharge state. This series of processing is repeatedly executed by the HV-ECU 51 (control unit) at a predetermined cycle while the vehicle is parked. Specifically, when this predetermined period has elapsed while the vehicle is parked, the HV-ECU 51 is activated by the verification ECU 52, and this series of processing is executed. For example, since the HV-ECU 51 is continuously activated when the activation signal line is in the on-fixed state, a series of processes are performed at this time. Further, when the discharge amount is increasing except when the activation signal line is in the on-fixed state, the HV-ECU 51 has not been activated yet, so the HV-ECU 51 is activated from the verification ECU via the relay IGB or the relay IG2. Let

  First, it is determined whether or not it is determined that the discharge amount of the auxiliary battery 21 is in a predetermined discharge state greater than a predetermined value (S31). Processing for determining whether or not the discharge state is the predetermined state will be described later.

  When it is determined that the battery is in the predetermined discharge state (S31: YES), it is determined whether a condition for starting charging in the predetermined discharge state is satisfied (S32). Specifically, based on the detection value of the sensor 22 that detects the state of the auxiliary battery 21, whether or not the charged amount of the auxiliary battery 21 is smaller than the charge start determination amount, and the charged amount of the main battery 31 is the lower limit amount. Determine if more.

  When it is determined that the condition for starting charging at the time of abnormality is satisfied (S32: YES), charging is started (S33). Then, with the target voltage set as a target, the DC / DC converter 42 steps down the power of the main battery 31 to charge the auxiliary battery 21. It should be noted that the amount of charge start determination for the amount of electricity stored in the auxiliary battery 21, the lower limit amount of the amount of electricity stored in the main battery 31, the predetermined target voltage, and the like may be the same value as or different from those during normal charging.

  Subsequently, it is determined whether or not a condition for ending charging in a predetermined discharge state is satisfied (S34). Specifically, based on the detection value of the sensor 22, it is determined whether or not the charged amount of the auxiliary battery 21 is larger than the charge end determination amount, or whether or not the charged amount of the main battery 31 is equal to or less than the lower limit amount. This charge end determination amount may be the same value as the normal charge or may be different. If the condition is not satisfied (S34: NO), the charging is continued and the process of S34 is executed again.

  If the condition for terminating the charging at the time of abnormality is satisfied (S34: YES), the charging is terminated (S35). Then, this series of processing ends.

  Next, details of a predetermined discharge state in which the discharge amount of the auxiliary battery 21 is larger than a predetermined value will be described.

  FIG. 6 shows determination of the relay IGBT on-fixed state as an example of processing for determining whether or not the discharge amount of the auxiliary battery 21 is in a predetermined discharge state larger than a predetermined value. This series of processing is repeatedly executed by the HV-ECU 51 (determination unit) while the vehicle is parked.

Since the output of the relay IGB is fixed in the on state, the verification ECU 52 controls the relay IGB in the off state, but the output via the relay IGB remains in the on state. The determination unit determines whether or not the relay IGB is controlled to be in an OFF state and the output via the relay IGB is ON (S41). When these conditions are satisfied (S41: YES), it is determined that the relay IGB is in an on state and fixed, and this state is determined to be a predetermined discharge state in which the discharge amount of the auxiliary battery 21 increases ( S42).
In addition, it is determined whether or not the battery is in a predetermined discharge state as follows.

  The determination unit determines whether or not the time during which the output via the relay IGB is on has elapsed for a predetermined time or more, determines that this state is the on-fixed state of the relay IGB, and assumes the predetermined discharge state.

  The determination unit determines whether or not the relay IG2 is controlled to be in an off state, and whether or not the output via the relay IG2 is on, determines that this state is the on-fixed state of the relay IG2, and in a predetermined discharge state Suppose there is.

  The determination unit determines whether the output via the relay IG2 is on and whether the output via the relay IGB is on, and this state is determined that either the relay IG2 or the relay IGB is in an on-fixed state. Suppose that it is a predetermined discharge state. However, this determination is not applicable to the control in which the relay IG2 and the relay IGB are simultaneously controlled to be turned on (for example, when one of the relay IG2 and the relay IGB is used as the other dual system).

  The determination unit determines whether or not it is a state in which a certain abnormality has occurred and the main battery cooling fan is continuously driven during parking as fail-safe, and is in a predetermined discharge state.

  Similarly, for other items listed as the predetermined discharge state, it is determined whether or not the item is established, and the predetermined discharge state is assumed.

The embodiment described in detail above has the following advantages.
-Electric power is supplied to the auxiliary machine of the vehicle by the auxiliary battery 21. Further, it is determined that the discharge amount of the auxiliary battery 21 is in a predetermined discharge state larger than a predetermined value. When it is determined that the battery is in a predetermined discharge state, the power of the main battery 31 is stepped down by the DC / DC converter 42 while the vehicle is parked, and the auxiliary battery 21 is charged. For this reason, even when the discharge amount of the auxiliary battery 21 increases, as long as the consumption amount of the main battery 31 is allowed, it is possible to suppress the decrease of the storage amount of the auxiliary battery 21, During this time, the rise of the auxiliary battery 21 can be suppressed. Further, when an abnormality occurs during the charging of the auxiliary battery 21, depending on the type of abnormality, the charging can be performed without stopping the charging halfway.

  The relay IGB connection command is compared with the output state via the relay IGB to determine the relay IGB on-fixed state, and this state is assumed to be a predetermined discharge state. Thus, when an abnormality occurs in which the IGB is fixed on, the auxiliary battery 21 can be charged by determining that the discharge state of the auxiliary battery 21 is in a predetermined discharge state. Similarly, the ON-fixed state of the relay IG2 and the relay IGCT can also be determined, and it can be determined that it is in a predetermined discharge state and the auxiliary battery 21 can be charged.

  The state of the output via the relay IGB and the state of the output via the relay IG2 are compared, and it is determined that either the relay IGB or IG2 is in an on-fixed state, and this state is assumed to be a predetermined discharge state. As a result, it is determined that the discharge state of the auxiliary battery 21 is increased and the auxiliary machine battery 21 is in a predetermined discharge state when an abnormality occurs in which the IGB or IG2 is stuck on in a state where the control command of the IGB or IG2 cannot be received. The battery 21 can be charged.

  It is determined whether or not it is in a state where the main battery cooling fan is continuously driven during parking as a fail-safe due to a certain abnormality, and is in a predetermined discharge state. Thereby, it can be determined that the discharge state of the auxiliary battery 21 is in a predetermined discharge state and the auxiliary battery 21 can be charged.

  Similarly, it is determined whether or not the items listed as the predetermined discharge state are established, and it is assumed that the predetermined discharge state is set. Thereby, it can be determined that the discharge state of the auxiliary battery 21 is in a predetermined discharge state and the auxiliary battery 21 can be charged.

  It should be noted that the first embodiment may be modified as follows.

  -The process which determines whether it is a predetermined discharge state may be repeatedly performed not only while the vehicle is parked but by the HV-ECU 51 (determination unit). Therefore, when it is determined that the vehicle is in a predetermined discharge state during driving of the vehicle, the auxiliary battery 21 may be charged while the vehicle is parked. According to such a configuration, it is possible to suppress a state in which the discharge amount increases and the auxiliary battery goes up until the auxiliary battery 21 is parked for the next time after driving.

(Second Embodiment)
Hereinafter, the second embodiment will be described focusing on differences from the first embodiment. In this embodiment, as shown in FIG. 7, when it is determined by the HV-ECU 51 that the battery is in the predetermined discharge state, the charging state is changed from the normal charging state to the charging state applied in the predetermined discharging state.

  First, it is determined whether or not the discharge amount of the auxiliary battery 21 is in a predetermined discharge state that is greater than a predetermined value (S51). If it is not the predetermined discharge state, the normal charge state is continued (S52). On the other hand, when it is a predetermined discharge state, it changes to the charge state applied to a predetermined discharge state (S53).

  In the charge state applied to the predetermined discharge state, the charge amount to the auxiliary battery 21 is changed to be increased. Specifically, the charge amount of the auxiliary battery 21 is increased or the charge target voltage is increased, or the charging current or the charging time is increased, so that the charge amount to the auxiliary battery 21 is increased.

  However, in order to continue the charging of the auxiliary battery 21 while suppressing the temperature rise of the equipment, wiring, and auxiliary battery 21 during charging, the charge amount to the auxiliary battery 21 is changed to be reduced, In some cases, charging is performed.

  Moreover, in order to make it easy to perform charging in the predetermined discharge state, the charge start condition and the charge end condition are changed.

  Similarly, in order to make it easier to perform charging in the predetermined discharge state, the predetermined time for determining the parking time is changed to be shortened.

  Then, the auxiliary battery 21 is charged based on the changed predetermined charging state.

  The embodiment described in detail above has the following advantages.

  When the predetermined condition is satisfied while the vehicle is parked, the auxiliary battery 21 is charged in a predetermined charging state. Here, when it is determined that the discharge amount of the auxiliary battery 21 is in a predetermined discharge state larger than a predetermined value, the predetermined charge state in the charge is increased or decreased so that the charge amount to the auxiliary battery 21 is increased. change. Thereby, even if the discharge amount of the auxiliary battery 21 increases, as long as the consumption amount of the main battery 31 is allowed, it is possible to suppress the decrease of the storage amount of the auxiliary battery 21, During this time, the rise of the auxiliary battery 21 can be suppressed. Further, when an abnormality occurs during the charging of the auxiliary battery 21, depending on the type of abnormality, the charging can be performed without stopping the charging halfway.

  Note that the second embodiment may be modified as follows.

  -When it is a predetermined discharge state, you may increase the charge start determination amount as an aspect which changes so that charging may be performed easily. When the discharge amount of the auxiliary battery 21 increases, according to such a configuration, charging of the auxiliary battery 21 can be started at an early stage when the discharge amount of the auxiliary battery 21 increases.

  Further, the first and second embodiments may be modified as follows. About the same member as 1st and 2nd embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  The HV-ECU 51 (determination unit) is in a predetermined discharge state when the current supplied from the auxiliary battery 21 is larger than a predetermined value based on the detection value of the sensor 22 that detects the state of the auxiliary battery 21. It can also be determined that there is.

  -HV-ECU51 (determination part) can also determine with it being a predetermined discharge state, when the execution time of charge of an auxiliary machine battery passes timeout time.

  -Verification ECU52 (determination part) can also detect the output state of relay IGB, relay IG2, and relay IGCT based on communication with HV-ECU51, and can also determine whether it is a predetermined discharge state. And when collation ECU52 determines with it being a predetermined discharge state, you may control relay IGB to ON state in order to perform charge.

  When charging the auxiliary battery 21, if there is a possibility that the stored amount of the main battery 31 reaches the lower limit, charging of the auxiliary battery may be prohibited.

  As shown in FIG. 8, a configuration in which the verification ECU 52 and the HV-ECU 51 are connected by a signal wiring 54A (parking activation signal line) and a signal wiring 56A (normal activation signal line) may be employed. The verification ECU 52 controls the output signal of the signal wiring 54A to be in an ON state under the condition that the relay IGB is controlled to be in an ON state (connection command ON) in the first embodiment, and controls the relay IG2 to be in an ON state in the first embodiment ( The output signal of the signal wiring 56A is controlled to be turned on under the condition that the connection command is turned on. And HV-ECU51 controls relay IGCT to an ON state, when at least one of the output signal of signal wiring 54A and the output signal of signal wiring 56A is ON. In such a configuration, instead of the output via the relay IGB being on, the output signal of the signal wiring 54A is turned on, and instead of the output via the relay IG2 being on, the signal wiring 56A. If the output signal is ON, the same effects as those of the first and second embodiments can be obtained.

  -It can also be embodied in an electric vehicle not equipped with an engine or a fuel cell vehicle further equipped with a fuel cell as an energy source.

  The auxiliary battery 21 and the main battery 31 can be embodied regardless of the type of battery such as a lead battery or a lithium ion battery.

  DESCRIPTION OF SYMBOLS 10 ... Power supply system, 12 ... Load, 21 ... Auxiliary battery, 31 ... Main battery, 33 ... Bat-ECU, 41 ... PCU, 51 ... HV-ECU, 52 ... Verification ECU.

Claims (22)

A vehicle power supply system (10) comprising:
An auxiliary battery (21) for supplying electric power to the auxiliary devices (12, 33, 41, 51, 52) of the vehicle;
A main battery (31) for supplying electric power to the drive motor of the vehicle;
A power converter (42) for charging the auxiliary battery by stepping down the power supplied from the main battery;
A control unit (51, 52) for operating the power conversion device while the vehicle is parked to charge the auxiliary battery in a predetermined charging state,
The control unit determines that the discharge state of the auxiliary battery is a predetermined discharge state when the discharge amount of the auxiliary battery is greater than a predetermined value, and determines that the predetermined discharge state is obtained by the determination unit. A charging execution unit (51, 52) for executing the charging by the power conversion device during parking of the vehicle,
A vehicle power supply system comprising: A vehicle power supply system (10) comprising:
An auxiliary battery (21) for supplying electric power to the auxiliary devices (12, 33, 41, 51, 52) of the vehicle;
A main battery (31) for supplying electric power to the drive motor of the vehicle;
A power converter (42) for charging the auxiliary battery by stepping down the power supplied from the main battery;
A control unit (51, 52) that causes the power conversion device to execute the charging in a predetermined charging state when a predetermined condition is satisfied while the vehicle is parked,
The control unit determines that the discharge state of the auxiliary battery is a predetermined discharge state when the discharge amount of the auxiliary battery is greater than a predetermined value, and determines that the predetermined discharge state is obtained by the determination unit. A charging execution unit (51, 52) for changing the predetermined charging state in the charging,
A vehicle power supply system comprising:   The said control part determines with the determination part being the predetermined discharge state from which the discharge amount of the said auxiliary battery becomes larger than a predetermined value, when the electric current of the said auxiliary battery is larger than a predetermined value. The power supply system for a vehicle according to 1 or 2.   The said control part changes the said predetermined charge state so that the charge amount to the said auxiliary battery in the said charge may be increased or decreased by the said charge execution part, The any one of Claims 1-3 Vehicle power system.   The power supply system for a vehicle according to any one of claims 1 to 4, wherein the control unit changes the predetermined charging state so as to increase or decrease a charging current in the charging.   The vehicle control system according to claim 1, wherein the control unit changes the predetermined charging state so as to extend or shorten a charging time in the charging.   The vehicle power supply system according to claim 1, wherein the control unit changes the predetermined charging state so as to increase or decrease a charging voltage in the charging.   The control unit according to any one of claims 1 to 7, wherein when the determination unit determines that the predetermined discharge state is set, the control unit changes a predetermined condition for performing the charge so that the charge is easily performed. The power supply system for a vehicle according to item 1.   The vehicle power supply system according to claim 8, wherein the control unit changes the predetermined condition so as to shorten an interval at which the charging is performed.   The power supply system for a vehicle according to claim 8 or 9, wherein the control unit changes the predetermined condition so as to increase a charge amount of the auxiliary battery serving as a reference for executing the charging. The control unit includes a parking start signal line (54) connected on the condition that the charging is performed,
The said determination part determines that it is the said predetermined discharge state, when the control signal which connects the said parking start signal line is OFF, when a parking start signal line is ON. The vehicle power supply system according to claim 1. A normal start signal line (56) connected to the control unit on the condition that the vehicle is in operation by turning on the start switch, and a parking start connected on the condition that the charging is being performed A signal line,
The vehicle according to any one of claims 1 to 11, wherein the determination unit determines that the predetermined discharge state is established when both the normal activation signal line and the parking activation signal line are in an on state. Power system. The control unit includes a parking start signal line that is connected on the condition that the charging is performed,
The determination unit continues the parking activation signal line when the control command for connecting the parking activation signal line exceeds a predetermined time, which is a maximum time for continuing the on state, when the charging is performed. The power supply system for a vehicle according to any one of claims 1 to 12, wherein the vehicle is determined to be in the predetermined discharge state when it is performed.   The power supply system for a vehicle according to any one of claims 1 to 13, wherein the determination unit determines that the predetermined discharge state is in a case where the auxiliary machine is continuously driven during parking as fail-safe accompanying abnormality. . Equipped with a cooling fan to cool the equipment,
The power source of the vehicle according to any one of claims 1 to 14, wherein the determination unit determines that the predetermined discharge state is in a case where the cooling fan is continuously driven during parking as fail-safe accompanying abnormality. system. A current sensor (22) for detecting the current of the auxiliary battery;
The vehicle power supply system according to any one of claims 1 to 15, wherein the determination unit determines that the predetermined discharge state is present when a current detected by the current sensor is larger than a predetermined value.   The power supply system for a vehicle according to any one of claims 1 to 16, wherein the control unit causes the power conversion device to execute the charging when a predetermined parking time has elapsed for the vehicle.   The vehicle power supply system according to claim 17, wherein the parking time is a time based on a stop time of a start switch of the vehicle.   18. The vehicle power supply system according to claim 17, wherein the parking time is a time based on a stop time of the vehicle power supply system.   The said charge is performed by the said power converter device during parking of the said vehicle, when the said determination part determines with the said determination part being during the driving | running | working of the said vehicle, The any one of Claims 1-19 Vehicle power system.   The power supply system for a vehicle according to any one of claims 1 to 20, wherein the charging is not executed when a storage amount of the main battery is equal to or less than a predetermined value.   The vehicle power supply system according to any one of claims 1 to 21, wherein the charging is not executed when a storage amount of the auxiliary battery is equal to or greater than a predetermined value.

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