JP2006262577A - Power system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply system capable of determining the possible causes of failures, in an accessory system. <P>SOLUTION: An ECU30 stops an accessory machine (1)10 when the electric power supplied from a DC-DC converter 40 exceeds a predetermined level. When the electric power, supplied from the DC-DC converter 40, is in excess of the predetermined level, even if the accessory machine (1)10 is stopped, the ECU30 electrically disconnects an accessory machine battery 50 from the DC-DC converter 40 by a relay 70. With both the accessory machine (1)10 and the accessory machine battery 50 stopped, the electric power supplied from the DC-DC converter 40 is checked, and when the power is determined as being within the predetermined level, the accessory machine battery 50 is determined to have some failure, such as deterioration in the accessory machine battery 50. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power supply system mounted on a vehicle, and more particularly to a power supply system that supplies electric power to auxiliary equipment.

  The vehicle is equipped with various auxiliary equipment. Auxiliary equipment is, for example, various lighting equipment, air conditioning equipment, audio equipment, and the like. In general, auxiliary equipment mounted on a vehicle is configured to be connected to an auxiliary battery and receive a stable supply of electric power. The auxiliary battery is supplied with electric power mainly from the vehicle drive system.

  For example, an electric vehicle or a hybrid vehicle is equipped with a high voltage battery for supplying electric power to a vehicle driving motor or an inverter, and the auxiliary battery or auxiliary equipment is supplied from the high voltage battery via a DC / DC converter. Is supplied with power.

  The electric power output from the DC / DC converter changes in an amount commensurate with the connected auxiliary equipment and auxiliary battery. However, if an abnormality occurs on the auxiliary system side and the current value flowing into the auxiliary system side becomes extremely large, more power is required than is normally expected, and the DC / DC converter exceeds the performance limit. It could end up breaking down.

  For this reason, a technique is known in which the DC / DC converter is stopped by a protection function when the current flowing from the DC / DC converter to the auxiliary system side reaches a predetermined amount or more (Patent Document 1, etc.).

JP 2000-245147 A

  By stopping the DC / DC converter by the protection function, a failure of the DC / DC converter can be avoided. However, simply by stopping the DC / DC converter, it is not possible to specify where the cause of the abnormality is on the side of the auxiliary system that has caused the stop.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a power supply system that can determine the cause of an abnormality in an auxiliary system.

  In order to achieve the above object, a power supply system according to a preferred aspect of the present invention includes a plurality of auxiliary equipment mounted on a vehicle, an auxiliary battery connected to the plurality of auxiliary equipment, and a plurality of auxiliary equipment. A power supply unit that supplies power to the auxiliary machine device and the auxiliary battery, and an auxiliary machine system control unit that controls the plurality of auxiliary machine devices and the auxiliary battery, and the auxiliary machine control unit includes: When the power supplied from the power supply unit exceeds a predetermined amount, stop at least one auxiliary machine device predetermined from the plurality of auxiliary machine devices, and stop the auxiliary machine device If the power supplied from the power supply unit exceeds a predetermined amount, the auxiliary battery is electrically disconnected from the power supply unit.

  In the above configuration, the auxiliary equipment includes, for example, various lighting equipment, air conditioning equipment, audio equipment, and the like. Specific examples of the power supply unit include a DC / DC converter and an alternator. That is, in an electric vehicle, a hybrid vehicle, etc., electric power is supplied from the high voltage battery to the auxiliary battery and auxiliary equipment via the DC / DC converter. In an engine vehicle, rotational drive energy obtained by the engine is converted into electric power by an alternator and supplied to an auxiliary battery or auxiliary equipment.

  According to the above configuration, based on whether the power supplied from the power supply unit exceeds a predetermined amount, there is a cause of abnormality in the auxiliary equipment, or there is a cause of abnormality such as deterioration in the auxiliary battery. It becomes possible to judge whether there is.

  Preferably, the auxiliary system control unit is configured to select a plurality of auxiliary machine devices determined in advance from the plurality of auxiliary machine devices when the power supplied from the power supply unit exceeds a predetermined amount. It is characterized in that it is stopped in stages according to the priority order, and it is confirmed whether or not the power supplied from the power supply unit exceeds a predetermined amount each time each auxiliary equipment is stopped.

  Preferably, the auxiliary system control unit is supplied with electric power from the auxiliary battery or the power supply unit via a voltage drop compensation circuit. Preferably, the power supply unit is a DC / DC converter connected to a high voltage battery for driving a vehicle.

  The present invention provides a power supply system that can determine the cause of an abnormality in an auxiliary machine system. For example, it is possible to determine whether there is an abnormality cause in the auxiliary equipment or whether there is an abnormality cause such as deterioration in the auxiliary battery.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 shows a preferred embodiment of a power supply system according to the present invention. FIG. 1 is a configuration diagram of a power supply system mounted on a vehicle. The power supply system of the present embodiment includes a plurality of auxiliary equipment (auxiliary equipment (1) 10 and auxiliary equipment (2) 20), an auxiliary battery 50, a DC / DC converter 40, and an ECU 30. Yes.

  The plurality of auxiliary machine devices are, for example, various lighting devices, air conditioning devices, audio devices, and the like. The auxiliary battery 50 is, for example, a 12V battery, and is provided to supply stable power to the auxiliary equipment. Auxiliary battery 50 is electrically connected to a plurality of auxiliary equipment and DC / DC converter 40 via relay 70.

  The DC / DC converter 40 functions as a power supply unit that supplies power to a plurality of auxiliary equipment and the auxiliary battery 50. The power supply system of this embodiment is mounted on an electric vehicle that uses a motor as a power source, a hybrid vehicle that uses an engine and a motor as power sources, and the like. An electric vehicle or a hybrid vehicle is equipped with a high voltage battery 60 that supplies electric power to a vehicle driving motor or an inverter. For example, the voltage value of the high voltage battery 60 is maintained at 200V to 300V. Therefore, power is supplied from the high voltage battery 60 to the plurality of auxiliary equipment and the auxiliary battery 50 via the DC / DC converter 40 by the pressure reducing function of the DC / DC converter 40. Incidentally, three-phase AC power is supplied from the high-voltage battery 60 to a vehicle drive motor (not shown) via an inverter (not shown), thereby realizing vehicle travel by the motor.

  The power supply unit in the present invention is not limited to the DC / DC converter 40. For example, the present invention may be applied to an engine vehicle in which rotational drive energy obtained by an engine is converted into electric power by an alternator and electric power is supplied to a plurality of auxiliary equipment and auxiliary battery 50. That is, in this case, the alternator corresponds to the power supply unit in the present invention.

  The ECU 30 functions as an auxiliary machine control unit that controls a plurality of auxiliary machine equipment and the auxiliary battery 50. The ECU 30 includes a hardware configuration (not shown) such as a CPU, a ROM, and a RAM, and an operation for controlling a plurality of auxiliary equipment and the auxiliary battery 50 is performed by a program that cooperates with the hardware configuration. Realized. The control operation by the ECU 30 will be described in detail later using FIG.

  The ECU 30 is supplied with electric power from the auxiliary battery 50 or the DC / DC converter 40 via a compensation circuit including a diode D and a capacitor C that function as a voltage drop compensation circuit. The anode terminal of the diode D is connected to the plus terminal side of the auxiliary battery 50 via the relay 70, and the cathode terminal is connected to the power source plus terminal of the ECU 30. The capacitor C is inserted in parallel between the power terminals (plus and minus) of the ECU 30. With this circuit configuration, the capacitor C functions as a temporary rechargeable battery for the ECU 30. That is, even when the output voltage of the auxiliary battery 50 rapidly decreases, the operation of the ECU 30 can be temporarily compensated by the electric charge accumulated in the capacitor C.

  In the power supply system of the present embodiment, when any abnormality occurs in a plurality of auxiliary equipment and auxiliary battery 50, the cause of the abnormality can be determined. For example, it is possible to determine which of a plurality of auxiliary equipment has a cause of abnormality, or whether there is an abnormal cause such as deterioration in the auxiliary battery 50. The determination of abnormality is realized mainly by the operation of the ECU 30. Therefore, the operation of the ECU 30 will be described in detail below. In the following description, the parts shown in FIG.

  FIG. 2 is a diagram for explaining the abnormality cause determination process in the present embodiment, and FIG. 2 is a flowchart showing the operation of the ECU 30. This flow is periodically executed at an interval of once every 10 ms, for example, in a state where electric power is supplied from the auxiliary battery 50 or the DC / DC converter 40 to a plurality of auxiliary equipment. Hereinafter, processing contents will be described for each step of the flowchart shown in FIG.

  (S201) First, the ECU 30 determines whether or not the electric power supplied from the DC / DC converter 40 exceeds a predetermined amount by confirming whether the output current value of the DC / DC converter 40 is equal to or larger than the predetermined amount.

  The electric power output from the DC / DC converter 40 changes in an amount commensurate with a plurality of auxiliary equipment devices and the auxiliary battery 50 to be connected in a normal time. For example, the voltage output from the DC / DC converter 40 is set to about 13V to 14V if a plurality of connected auxiliary equipment or auxiliary battery 50 is a 12V system. Then, the limit value of the current output from the DC / DC converter 40 is set according to a plurality of auxiliary equipment connected.

  As described above, generally, the DC / DC converter 40 having a limit performance set according to the normal power consumption of the auxiliary equipment connected thereto is used. However, if an abnormality occurs in the auxiliary equipment connected to the equipment, there may be a case where electric power that greatly exceeds the amount assumed during normal operation is required. In the present embodiment, this large excess of power is determined by the output current value of the DC / DC converter 40. That is, the ECU 30 confirms a current value from a current sensor (not shown) provided at the output terminal of the DC / DC converter 40 and confirms whether the current value is equal to or greater than a predetermined current value. The predetermined current value is set according to the auxiliary machine system to be connected. In the present embodiment, it is assumed that 100A is set, for example.

  If it is determined in S201 that the output current value is not greater than or equal to the predetermined amount, it is determined that there is no abnormality in the auxiliary equipment and the auxiliary battery 50 at the present time, and this flow is ended. If it is determined in S201 that the output current value is greater than or equal to the predetermined amount, the process proceeds to the next step for further confirmation.

  (S202) The ECU 30 outputs a stop command to the auxiliary equipment (1) 10 to stop the operation of the auxiliary equipment (1) 10. As described with reference to FIG. 1, the plurality of auxiliary equipment is various lighting equipment, air conditioning equipment, audio equipment, and the like, and each auxiliary equipment consumes various electric power depending on its use. is there. For this reason, some auxiliary equipment operates with a very small amount of power that hardly affects the overall power consumption of a plurality of auxiliary equipment. Auxiliary equipment with large power consumption also exists. In this embodiment, the auxiliary equipment (1) 10 is an auxiliary equipment with a large power consumption, and the auxiliary equipment (2) 20 is an auxiliary equipment that operates with a very small amount of power. In S202, the operation of the auxiliary equipment (1) 10 having a large power consumption is stopped.

  (S203) Next, the ECU 30 checks whether or not the output current value of the DC / DC converter 40 is equal to or larger than a predetermined amount in a state where the auxiliary equipment (1) 10 is stopped. That is, it is confirmed whether or not the current value is greater than or equal to a predetermined current value (for example, 100 A, which is the same as S201) in a state where the auxiliary equipment (1) 10 is stopped.

  If it is determined in S203 that the output current value is not greater than or equal to the predetermined amount, it is presumed that there is some abnormality cause in the auxiliary equipment (1) 10. Therefore, in this case, the auxiliary equipment (1) 10 is stopped for a predetermined time in S204. For example, the time until the temperature of the DC / DC converter 40 falls to the normal temperature is set as the predetermined time. Then, after a predetermined time has elapsed, the auxiliary equipment (1) 10 is operated and this flow is started again. If S204 is reached even after this flow is started again, the auxiliary equipment (1) 10 may be stopped for a predetermined time and the situation may be observed, but there is some abnormality in the auxiliary equipment (1) 10. You may judge that there is. Thus, in this embodiment, it can be determined that there is an abnormality in the auxiliary equipment (1) 10 among the plurality of auxiliary equipment.

  (S205) When it is determined in S203 that the output current value is equal to or greater than the predetermined amount, the ECU 30 outputs the shut-off command to the relay 70 of the auxiliary battery 50, whereby the auxiliary battery 50 is removed from the DC / DC converter 40. Disconnect electrically. That is, since the output current value does not decrease even when the auxiliary equipment (1) 10 having a large power consumption is stopped, it is presumed that there is some abnormality cause in the auxiliary battery 50. Therefore, the auxiliary battery 50 is electrically disconnected from the DC / DC converter 40 and further confirmation is performed in the next step.

  (S206) The ECU 30 checks whether the output current value of the DC / DC converter 40 is equal to or greater than a predetermined amount in a state where the auxiliary machine system device (1) 10 and the auxiliary battery 50 are stopped. That is, it is confirmed whether or not the current value is equal to or greater than a predetermined current value (for example, 100 A, which is the same as S201) in a state where both the auxiliary equipment (1) 10 and the auxiliary battery 50 are stopped. If it is determined in S206 that the output current value is not greater than or equal to the predetermined amount, it is estimated that there is some abnormality cause in the auxiliary battery 50. Therefore, in this case, it is determined in S207 that the auxiliary battery 50 is abnormal (for example, a battery deterioration failure). Thus, in the present embodiment, it can be determined that the auxiliary battery 50 is abnormal among the plurality of auxiliary equipment and the auxiliary battery 50.

  (S208) If it is determined in S206 that the output current value is greater than or equal to the predetermined amount, the ECU 30 determines that there is a failure somewhere in the entire auxiliary system. For example, a short circuit between power supply terminals in the auxiliary equipment (2) 20 can be considered. Further, the stop operation of the auxiliary machine device (1) 10 performed in S202 is not normally performed, and it may be caused by a failure in the auxiliary machine device (1) 10. In addition, there may be a case where the wiring connecting the auxiliary equipment is short-circuited.

  The preferred embodiment of the present invention has been described above. In the present embodiment, the auxiliary equipment (2) 20 is kept operating without being stopped. For this reason, the structure which makes an important apparatus for vehicles the auxiliary equipment (2) 20 is desirable. For example, it is a configuration that maintains the operation of auxiliary equipment that is highly important in terms of safety, such as auxiliary equipment related to vehicle driving, auxiliary equipment related to brakes, and auxiliary equipment related to steering wheels.

  In S201 of FIG. 2 and the like, it is determined whether the power supplied from the DC / DC converter 40 exceeds a predetermined amount based on the output current value of the DC / DC converter 40. However, it may be determined whether the power exceeds a predetermined amount based on the power value. For example, in addition to the current sensor that measures the output current of the DC / DC converter 40, a voltage sensor that measures the output voltage of the DC / DC converter 40 is provided, and the current value obtained from the current sensor and the voltage obtained from the voltage sensor. The power value may be obtained by multiplying the value, and it may be determined whether or not the obtained power value exceeds a predetermined amount.

  Further, the present invention may be applied to a system having a plurality of auxiliary equipment (1) 10. In this case, each auxiliary machine (1) 10 is stopped in stages according to a predetermined priority order from among the plurality of auxiliary machines (1) 10, and each auxiliary machine (1) 10 is stopped. Each time, it is checked whether the power supplied from the DC / DC converter 40 exceeds a predetermined amount. That is, S202 to S204 in FIG. 2 are executed for each auxiliary equipment (1) 10 according to a predetermined priority order.

  For example, it is determined whether or not the power supplied from the DC / DC converter 40 exceeds a predetermined amount in a state where only the auxiliary equipment (1-1) of the first priority is stopped, and does not exceed the predetermined amount. In this case, the auxiliary equipment (1-1) is stopped for a predetermined time, and when the predetermined amount is exceeded, in addition to the auxiliary equipment (1-1), the auxiliary equipment (1- It is determined whether or not the electric power supplied from the DC / DC converter 40 exceeds a predetermined amount in the state where 2) is stopped. As a result, it is possible to determine which of the plurality of auxiliary equipment (1-1) and auxiliary equipment (1-2) has an abnormality, or is caused by another cause. Become.

  Further, in this embodiment, when an abnormality of the auxiliary equipment (1) 10 or deterioration of the auxiliary battery 50 is determined, an indicator indicating abnormality or deterioration may be lit on the front panel of the driver's seat or the like.

  Further, in S201 of FIG. 2 and the like, it is determined whether or not the output current value of the DC / DC converter 40 is, for example, 100 A or more. By setting this judgment value (predetermined amount) to be small, it is also possible to use it for confirmation of deterioration before abnormality occurs in the auxiliary equipment. For example, when 100 A is set as an output current value that is slightly lower than the limit performance of the DC / DC converter 40, about 70 A, which is lower than 100 A, is set as a predetermined value for determining deterioration. It is also possible to confirm the deterioration of the auxiliary equipment at a stage before the abnormality occurs in the mechanical equipment. An indicator may be lit on the front panel or the like for deterioration of the auxiliary equipment. Thereby, it is possible to notify the user of the deterioration before the abnormality occurs in the auxiliary equipment.

It is a block diagram of the power supply system which concerns on this invention. It is a figure for demonstrating the abnormality cause judgment process which concerns on this invention.

Explanation of symbols

  10 Auxiliary equipment (1), 20 Auxiliary equipment (2), 30 ECU, 40 DC / DC converter, 50 Auxiliary battery, 60 High voltage battery, 70 Relay.

Claims (4)

A plurality of auxiliary equipment mounted on the vehicle;
An auxiliary battery connected to a plurality of auxiliary equipment, and
A power supply unit for supplying power to a plurality of auxiliary equipment and auxiliary batteries;
Auxiliary system control unit for controlling a plurality of auxiliary equipment and auxiliary battery,
Have
The auxiliary machine control unit stops at least one auxiliary machine device determined in advance from the plurality of auxiliary machine devices when the power supplied from the power supply unit exceeds a predetermined amount. When the power supplied from the power supply unit exceeds a predetermined amount even when the auxiliary equipment is stopped, the auxiliary battery is electrically disconnected from the power supply unit.
A power supply system characterized by that. The power supply system according to claim 1,
The auxiliary system control unit, when the power supplied from the power supply unit exceeds a predetermined amount, assigns a plurality of predetermined auxiliary machine devices from the plurality of auxiliary machine devices according to priority. Stop in stages and check whether the power supplied from the power supply unit exceeds a predetermined amount each time each auxiliary machine is stopped,
A power supply system characterized by that. The power supply system according to claim 2,
The auxiliary machine system control unit is supplied with power from the auxiliary battery or the power supply unit via a voltage drop compensation circuit.
A power supply system characterized by that. In the power supply system according to claim 3,
The power supply unit is a DC / DC converter connected to a high voltage battery for driving a vehicle.
A power supply system characterized by that.

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