JP2012006532A - Power supply device for vehicles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device for a vehicle which can secure the normal operation of a load unit without causing a cost increase when short-circuit occurs in one of a plurality of load units.SOLUTION: A power supply device for a vehicle which has power supply lines 5 parallelly pulled out of a vehicle power source 1 and a plurality of load units 2, 3, 4 connected to respective parallel power supply lines 5, is provided with a controller 21 for detecting short-circuit in which an excessive current flows into an electric booster 2 of a plurality of load units 2, 3, 4, and a VDC/TCS/ABS controller 7 for outputting to a step-up circuit 10 a pressure increasing command for increasing a normal voltage of an electric hydraulic circuit 3 to at least lowest operating voltage when a short-circuit flag is set as short-circuit information from a controller 21.

Description

  The present invention relates to a vehicle power supply apparatus in which a plurality of load units are connected in parallel to a vehicle power supply via a power supply line.

  Conventionally, in a configuration in which a power supply line is provided in parallel from a vehicle power supply and a plurality of load units are connected to each of the parallel lines, when the power supply line or the load unit is grounded and a short-circuit current flows, a short-circuited power supply line Shut off. Thus, a vehicular power supply device that enables continuous power supply to a load other than a shorted power line is known (see, for example, Patent Document 1).

JP 2004-338777 A

  However, in the conventional vehicle power supply apparatus, when a short circuit occurs, the short circuit current is interrupted when the short circuit diagnosis is confirmed. For this reason, if an excessive short circuit current flows between the occurrence of a short circuit and the short circuit current is cut off, the power supply voltage drops and the power supply voltage falls below the minimum operating voltage. There was a problem that stopped.

  This is because, in the conventional apparatus, a general load unit connected to a power supply line of a vehicle has a minimum operating voltage. In addition, after detecting the short-circuit current, the interruption is executed after the short-circuit diagnosis is confirmed, so that there is a delay time from the detection time of the short-circuit current to the interruption. This point is not taken into consideration.

  As a vehicle power source, a general gasoline vehicle has a configuration of an alternator + battery, and a hybrid vehicle or an electric vehicle has a configuration of a DC / DC converter + battery in many cases. In this configuration, when a large current is consumed due to a short circuit downstream of the vehicle power supply, each of the load units is affected by a voltage drop.

  On the other hand, in order to continue to operate the load unit without being affected by the short-circuit current, the vehicle power supply by a battery with a large current capacity should be used so that it does not fall below the minimum operating voltage even if there is a delay time in the interruption. In this case, the cost becomes high.

  The present invention has been made paying attention to the above-described problem. When a short circuit occurs in any of a plurality of load units, the vehicle can ensure normal operation of the load unit without causing an increase in cost. An object is to provide a power supply device.

In order to achieve the above object, the vehicle power supply apparatus of the present invention has a power supply line provided in parallel from the vehicle power supply, and a plurality of load units are connected to each of the parallel power supply lines. The vehicle power supply apparatus includes first load unit control means and second load unit control means.
The first load unit control means detects a short circuit in which an excessive current flows through the first load unit among the plurality of load units.
When the short-circuit information is input from the first load unit control means, the second load unit control means outputs a boost command for boosting the voltage of the normal second load unit to at least the minimum operating voltage.

When short-circuit information is input from the first load unit control means, a boost command for boosting the voltage of the normal second load unit to at least the minimum operating voltage is output to the booster circuit in the second load unit control means. Therefore, when a short circuit occurs in the first load unit, if the short circuit information is input, the boost control for adding the boost voltage to the power supply voltage that decreases as the short circuit occurs is started. .
That is, the voltage of the second load unit can be maintained in a voltage state equal to or higher than the minimum operating voltage from an early point in time when the short circuit information is input without waiting for the short circuit current to be cut off on the first load unit side. . In this step-up control, since it is assumed that the power supply voltage is lowered, it is not necessary to increase the current capacity of the power supply voltage.
For this reason, when a short circuit occurs in any of the plurality of load units, normal operation of the load unit can be ensured without causing an increase in cost.

1 is an overall system diagram illustrating an electric vehicle power supply device (an example of a vehicle power supply device) according to a first embodiment. It is a circuit diagram which shows the electric booster which has the inverter circuit by a basic composition in the electric power supply apparatus for electric vehicles of Example 1. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram illustrating an example of a general booster circuit in an electric vehicle power supply device according to a first embodiment. It is a flowchart which shows the flow of the pressure | voltage rise control processing performed in a VDC / TCS / ABS controller in the electric vehicle power supply apparatus of Example 1. FIG. It is a figure which shows the pressure | voltage rise command table used by the pressure | voltage rise control process performed with the VDC / TCS / ABS controller in the electric power supply apparatus for electric vehicles of Example 1. FIG. It is explanatory drawing which shows the example of a short circuit generation | occurrence | production in an inverter circuit in the electric power supply apparatus for electric vehicles of Example 1. FIG. 3 is a time chart showing characteristics of a short circuit current, an electric booster detection flag, an interruption relay, and an electrohydraulic circuit voltage representing a boosting function in the electric vehicle power supply apparatus according to the first embodiment. 3 is a time chart showing characteristics of a short-circuit flag, a continuation counter, and a power supply boost flag representing a boosting duration in the electric vehicle power supply apparatus according to the first embodiment. It is a flowchart which shows the flow of the pressure | voltage rise control processing performed with the VDC / TCS / ABS controller in the electric power supply apparatus for electric vehicles of Example 2. FIG.

  Hereinafter, the best mode for realizing the vehicle power supply device of the present invention will be described based on Example 1 and Example 2 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram illustrating an electric vehicle power supply apparatus (an example of a vehicle power supply apparatus) according to a first embodiment. The overall system configuration will be described below with reference to FIG.

  As shown in FIG. 1, the electric vehicle power supply apparatus according to the first embodiment includes a vehicle power source 1, an electric booster 2 (first load unit), an electric hydraulic circuit 3 (second load unit), and a general load 4. (Load unit). A power supply line 5 is provided in parallel from the vehicle power supply 1, and an electric booster 2, an electrohydraulic circuit 3, and a general load 4, which are a plurality of load units, are connected to each of the parallel power supply lines 5.

  The vehicle power source 1 includes a DC / DC converter 11 and a lead battery 12, and an electric booster 2, an electric hydraulic circuit 3, and a general load 4 are connected in parallel downstream thereof. Here, the general load 4 is used as a general term for a plurality of load units other than the electric booster 2 and the electric hydraulic circuit 3.

  The electric booster 2 is provided in the brake device 6 and assists with a motor torque instead of a general negative pressure booster when the driver depresses the pedal effort. The electric booster 2 includes a controller 21 (first load unit control means), a cutoff relay 22, an inverter circuit 23, and a three-phase motor 24 (assist motor).

  The controller 21 calculates an input from the driver and sends a command to the inverter circuit 23. The three-phase motor 24 is controlled according to the command, and the driver input is assisted with a necessary amount of boost. In addition to this boost control, a short circuit in which an excessive current flows in the inverter circuit 23 is detected, and short circuit information is output. Further, when the short-circuit current becomes equal to or higher than the preset current, short-circuit diagnosis is started. If the short-circuit current is equal to or higher than the set current even after a predetermined diagnosis time has elapsed, the short-circuit diagnosis is confirmed and the relay relay 22 is turned on. In response to the command, the power to the inverter circuit 23 is cut off.

The electrohydraulic circuit 3 is an ABS actuator used for ABS / TCS / VDC control, and an oil pump motor 31 capable of self-increasing the brake fluid pressure and a plurality of valve solenoids capable of adjusting the brake fluid pressure of each wheel of the vehicle. 32, 33,...
Here, ABS / TCS / VDC control means that the vehicle attitude control function (VDC function), TCS function and ABS function are realized by the ABS / TCS / VDC unit to improve driving safety and support the driver. Control.

The ABS / TCS / VDC unit includes an electrohydraulic circuit 3 (ABS actuator), an ABS / TCS / VDC controller 7, various sensors 8, and an engine controller 9.
The ABS / TCS / VDC controller 7 detects the driver's driving operation and vehicle speed using various sensors 8, and automatically generates brake pressure (command to the electrohydraulic circuit 3) and engine output (command to the engine controller 9). Control. In addition, slippery road surfaces, cornering, and side slips that occur when avoiding obstacles are reduced to increase the sense of security during driving.
In recent years, ABS / TCS / VDC units are sometimes used as means for realizing ITS functions, and some units have high controllability (silent and high resolution). In addition, the driver feels uncomfortable with the operation feeling.

  The ABS / TCS / VDC controller 7 (second load unit control means) has established bidirectional communication with the controller 21 serving as the first load unit control means by local communication or CAN communication. When a short circuit flag (short circuit information) is input from the controller 21 by this communication, a boost command for boosting the voltage of the normal electrohydraulic circuit 3 to at least the minimum operating voltage is output to the boost circuit 10.

  FIG. 2 is a circuit diagram illustrating an electric booster having an inverter circuit according to a basic configuration in the electric vehicle power supply apparatus according to the first embodiment. Hereinafter, based on FIG. 2, the structure of the electric booster 2 is demonstrated.

  As shown in FIG. 2, the electric booster 2 includes a controller 21, a cutoff relay 22, an inverter circuit 23, and a three-phase motor 24.

  The cutoff relay 22 is a relay for cutting off the vehicle power supply 1 when the system is not operating or when an abnormality occurs and the system is stopped. Usually, it is commanded from the controller 21 in the electric booster 2.

The inverter circuit 23 includes a shunt resistor 23a and six changeover switches 23b, 23c, 23d, 23e, 23f, and 23g.
The shunt resistor 23a is a highly accurate resistor having a small resistance value for monitoring the current flowing from the power supply line 5 and maintaining the optimum state of the system. Actually, the flowing current is taken into the monitor circuit of the controller 21 as a potential difference.
The changeover switch 23b uses a power FET (hereinafter referred to as FET), and sequentially switches the upstream changeover switches 23b, 23c, 23d and the downstream changeover switches 23e, 23f, 23g to each phase (coil). The flowing current is controlled.

  The three-phase motor 24 is driven to rotate by switching each phase by high-speed switching by PWM from the inverter circuit 23. However, not only the three-phase motor 24 but also a DC brush motor or the like, the rotational drive control can be performed even if a mechanical relay or the like is used instead of the inverter circuit 23 with an H-bridge motor driver.

  FIG. 3 is a conceptual diagram illustrating an example of a general booster circuit in the electric vehicle power supply apparatus according to the first embodiment. The configuration of the booster circuit 10 will be described below with reference to FIG.

  As shown in FIG. 3, the booster circuit 10 includes a first switch SW1, a second switch SW2, a third switch SW3, a first capacitor C1, a second capacitor C2, and a booster battery 10a. Have.

  As an operation principle, the power supply voltage VB is stored in the first capacitor C1 by the first switch SW1: ON. Thereafter, when the first switch SW1: OFF and the second switch SW2 are switched, the potential becomes (VB + VD) obtained by adding the boosted voltage VD to the power supply voltage VB. Here, when the third switch SW3 is turned ON, (VB + VD) is stored in the second capacitor C2, and the output voltage Vout (= VB + VD) can be taken out.

  At this time, the output voltage Vout (= VB + VD) can be arbitrarily changed by setting the boosted voltage VD to an arbitrary voltage by dividing the resistance. Further, the technology of the booster circuit 10 has been established, and it can be set at a low cost by combining with the logic according to the flowchart of FIG. 4, and the vehicle power supply 1 can be reduced from large capacity to small capacity. Further, even if the increase in cost of the booster circuit 10 is subtracted, the reduction in power supply cost is larger, so that there is an effect of cost reduction.

  FIG. 4 is a flowchart illustrating the flow of the boost control process executed by the VDC / TCS / ABS controller 7 in the electric vehicle power supply apparatus according to the first embodiment. Hereinafter, each step of FIG. 4 will be described.

  In step S1, following the logic start, a short-circuit flag indicating a short-circuit state is received from the controller 21 of the electric booster 2 by communication, and the process proceeds to step S2.

  In step S2, following the reception of the short-circuit flag in step S1, it is determined whether the short-circuit flag is changed from OFF to ON and the flag is raised. If Yes (short circuit flag is OFF → ON), the process proceeds to step S4, and if No (short circuit flag is ON → OFF or OFF or ON), the process proceeds to step S14.

In step S3, following the determination that the short-circuit flag is OFF → ON in step S2, it is determined whether FLG = 0. If Yes (FLG = 0), the process proceeds to step S4. If No (FLG = 1), the process proceeds to step S9.
Note that the initial value of FLG is 0, and FLG = 1 when the voltage is recorded in step S4. This FLG performs counter reset and count continuation processing.

  In step S4, following the determination that FLG = 0 in step S3, the power supply voltage in the current electrohydraulic circuit 3 is recorded, and the process proceeds to step S5.

In step S5, following the recording of the power supply voltage in step S4, FLG = 0 is rewritten to FLG = 1, and the process proceeds to step S6.
Note that once FLG = 1 is rewritten, FLG = 1 is continued until the count reaches zero, so this FLG can be read in the count state.

  In step S6, following rewriting to FLG = 1 in step S5, it is determined whether or not the voltage needs to be boosted from the value of the power supply voltage read in step S4. If Yes (voltage that requires boosting), the process proceeds to step S7. If No (voltage that does not require boosting), the process proceeds to step S8.

  In step S7, following the determination in step S6 that the voltage needs to be boosted, a voltage to be boosted is set from a preset table (FIG. 5), and the process proceeds to step S10. Note that how to determine the table in FIG. 5 will be described later.

  In step S8, following the determination in step S6 that the voltage does not need to be boosted, FLG = 1 is rewritten to FLG = 0, and the process proceeds to return.

In step S9, following the determination in step S3 that FLG = 1, the voltage to be boosted remains in the previously set state, the count value representing the duration for issuing a command to the booster circuit 10 is reset, and boosting is performed again. The process proceeds to step S10.
That is, this is done because the same boosted voltage value is used until a series of down-counts is completed.

  In step S10, following the setting of the boosted voltage in step S7, the reset of the count value in step S9, or the determination that FLG = 1 in step S14, the booster circuit 10 is set so that the set voltage is obtained. The process proceeds to step S11.

In step S11, following the command to the booster circuit 10 in step S10, the count value is counted down, and the process proceeds to step S12.
In this embodiment, the completion condition is when the count value becomes 0 by down-counting, but it is also possible to set the upper limit by up-counting.

  In step S12, following the down-count in step S11, it is determined whether or not the count value is 0. If Yes (count value = 0), the process proceeds to step S13, and if No (count value ≠ 0), the process proceeds to return.

In step S13, following the determination in step S12 that the count value = 0, the boost ends, the count value is cleared, FLG = 0 (initial value), and the process proceeds to return.
If the count value remains, the process proceeds to return processing with p as it is.

In step S14, it is determined whether FLG = 0 following the determination that the short circuit flag is ON → OFF, OFF, or ON in step S2. If Yes (FLG = 0), the process proceeds to return, and if No (FLG = 1), the process proceeds to step S10.
That is, if FLG = 0, nothing is processed, and the process proceeds as it is. However, if FLG = 1, since the down-counting is in progress, the process proceeds to the process of continuing the down-count.

Next, the operation will be described.
The operations in the electric vehicle power supply device of the first embodiment are “short-circuit current generation and boosting operation”, “boosted voltage setting operation”, “boosting operation when short-circuit occurs”, and “boosting time determining operation”. This will be explained separately.

[Generation of short-circuit current and boosting action]
FIG. 6 is an explanatory diagram illustrating an example of occurrence of a short circuit in the inverter circuit 23 in the electric vehicle power supply apparatus according to the first embodiment. Hereinafter, the action of generating a short-circuit current will be described with reference to FIG.

  For example, when the changeover switch 23e on the GND installation side has a short circuit failure, when (1), (2), and (3) in FIG. Current will flow to the short circuit. In this case, current flows in direction A when (1) is ON, direction B when (2) is ON, and direction C when (3) is ON. As a result, the vehicle power supply 1 and ground GND are short-circuited. Almost the same phenomenon occurs. In FIG. 6, it passes through the coil (inductance) of the three-phase motor 24, but the three-phase motor 24 is generally designed to improve efficiency because it generates a torque proportional to the current. Therefore, since the resistance of the coil is small and often does not have a resistance value that can suppress the current, it can be said to be equivalent to a short circuit between the vehicle power supply 1 and the ground GND.

  As described above, in the case of an electric vehicle having a small-capacity vehicle power supply 1, an excessive current flows through the inverter circuit 23 of the electric booster 2 to lower the voltage to the electrohydraulic circuit 3 and stop the VDC / TCS / ABS unit. There is a possibility that.

  In such a case, the boost of the electric booster 2 is stopped and the driving support function by the electric hydraulic circuit 3 is also stopped. As for the boost stop of the electric booster 2, although the brake feeling is deteriorated, a deceleration that can be stopped by the driver's pedal effort can be generated. In contrast, when the electrohydraulic circuit 3 stops due to the occurrence of a short circuit on the electric booster 2 side, the driving support function (VDC function, TCS function, ABS function) stops, and the boost function in the electric booster 2 stops. It will have a significant effect compared to the case of doing so.

  In view of this, it is a great feature that the boosted voltage is generated so as not to fall below the minimum operating voltage of the electrohydraulic circuit 3 immediately after the short-circuit flag due to the short-circuit current is received and until the short-circuit current is interrupted by the interrupt relay 22. It is.

[Step-up voltage setting]
FIG. 5 is a diagram illustrating a boost command table used in the boost control process executed by the VDC / TCS / ABS controller 7 in the electric vehicle power supply apparatus according to the first embodiment. Hereinafter, the boosting voltage setting operation will be described with reference to FIG.

  As described above, how to set the boost voltage when generating the boost voltage will be described. Basically, an arbitrary boosted voltage is determined according to the voltage state of the electric booster 2 recorded by the electrohydraulic circuit 3. Boosting is performed using only the necessary voltage according to the set boost command table, and the booster circuit 10 that can vary the voltage is used.

In the boost command table, the horizontal axis represents the recording voltage on the electrohydraulic circuit 3 side when the short-circuit flag is received, and the vertical axis represents the boost command. The basic idea of the boost voltage setting in this boost command table is to boost when the recorded voltage value is low and not to boost when the recorded voltage value is high. This is because it is almost equivalent to the voltage of the vehicle power supply 1, and when the voltage of the vehicle power supply 1 is weakened, there is a high possibility that the electrohydraulic circuit 3 falls below the minimum operating voltage.
However, since the above is a general tendency, it is necessary to set the branch point to the maximum operating voltage side depending on the conditions of the power supply system.

  The boost command table illustrated in FIG. 5 is a value determined for each vehicle system. In particular, it can be estimated in advance from the amount of voltage drop (for example, battery transient characteristics) according to the amount of current used. Further, the vehicle power source 1 may be affected by temperature. In particular, at low temperatures below room temperature, the voltage drop with respect to the current drawn becomes large, so at such low temperatures, the position of the branch point that separates the presence or absence of boosting is raised to the maximum operating voltage side. It is also necessary to take.

[Pressure increase when short circuit occurs]
FIG. 7 is a time chart showing characteristics of a short-circuit current, an electric booster detection flag, an interruption relay, and an electric hydraulic circuit voltage representing a boosting function in the electric vehicle power supply apparatus according to the first embodiment. Hereinafter, based on the flowchart of FIG. 4 and FIG. 7, the boosting action when a short circuit occurs will be described.

  When a short-circuit flag indicating a short-circuit condition is received from the controller 21 of the electric booster 2 by communication, and the voltage of the electrohydraulic circuit 3 is a voltage that needs to be boosted, in the flowchart of FIG. 4, step S1 → step S2 → step It progresses to S3-> step S4-> step S5-> step S6-> step S7-> step S10. That is, by receiving the short-circuit flag only once, in step S10, the boost control is started by outputting a command to the boost circuit 10 so that the set boost voltage is obtained.

  From step S10, the process proceeds from step S11 to step S12 to return and returns to the logic start. As long as the short circuit flag is ON and the count value is not 0, in the flowchart of FIG. 4, the process of step S1 → step S2 → step S14 → step S10 → step S11 → step S12 → return is repeated. Control continues.

  When the continuation time of the boost control elapses and the count value becomes 0 by the down-count in step S11, the process proceeds from step S11 to step S12 to step S13 in the flowchart of FIG. 4, and the boost control is terminated.

The time chart shown in FIG. 7 shows the operation timing of the boosting function.
In FIG. 7, when a short circuit failure of the electric booster 3 (e-ACT) occurs at time t1, the short circuit flag (= electric booster detection flag) is turned from OFF to ON at time t2, and the boost control is started. The short circuit fault diagnosis of the electric booster 3 (e-ACT) is started.

  In other words, the value detected by the shunt resistor 23a is used as the short-circuit current, and the short-circuit flag is turned ON, assuming that a short-circuit current has occurred when the current exceeds a preset current (= detection current threshold). At the same time, short-circuit fault diagnosis is started.

  In order to reliably determine that a short-circuit current has occurred, it is necessary to take a certain amount of time for diagnosis. Therefore, after the short circuit failure diagnosis of the electric booster 3 (e-ACT) is confirmed at the time t3 in FIG. 7, the actual interruption (time t4) from the interruption command to the interruption relay 22 takes more time. The time taken to deal with the short-circuit current is (diagnosis time (t2 to t3) + break time (t3 to t4)).

This time, since the boosting is started immediately after receiving the short-circuit flag detected on the electric booster 2 side by communication, the boosting is delayed as shown in the characteristics of the electrohydraulic circuit voltage after the countermeasure in FIG. And can be prevented from dropping to the minimum operating voltage.
Incidentally, when boosting is not performed, as shown in the characteristics of the electrohydraulic circuit voltage before the countermeasure in FIG. 7, the electrohydraulic circuit voltage operates at the minimum at the timing of time t2 ′ between time t2 and time t3. Then, the operation of the VDC / TCS / ABS unit using the electrohydraulic circuit 3 is stopped.

  Immediately after receiving the short-circuit current flag, the electric hydraulic circuit 3 side reads and records its own voltage state at that time. A necessary voltage amount can be selected by determining the necessity of boosting based on this recording voltage. For example, it is possible to divide the voltage so that the voltage is not boosted if the power source is higher than the normal state, and the voltage is boosted if the power source is lower than the normal state. Although this separation voltage value varies depending on the configuration of the vehicle power source to be combined, for example, it can be said that boosting is not performed near the maximum operating voltage. If operating near the maximum operating voltage, the voltage may be difficult to decrease, and if it is increased uniformly, the maximum operating voltage may be further increased. There is no problem because the design includes the behavior when the maximum operating voltage is exceeded, but there is no problem, but depending on the conditions, you do not want to boost as much as possible because you do not want to apply unnecessary loads such as a power supply exceeding the maximum operating voltage . However, if this vicinity is also necessary due to the capacity of the vehicle power supply, it is necessary to take measures such as limiting the upper limit.

[Determination of boosting time]
FIG. 8 is a time chart showing characteristics of a short-circuit flag, a continuation counter, and a power supply boost flag representing the boosting duration in the electric vehicle power supply apparatus according to the first embodiment. The boosting time determination operation will be described below with reference to the flowchart of FIG. 4 and FIG.

  For example, when the short-circuit flag is switched from OFF to ON due to noise, not due to a short circuit (time t1 in FIG. 8) and the short-circuit flag is received by communication, in the first activation, step S1 → Step S2 → Step S3 → Step S4 → Step S5 → Step S6 → Step S7 → Step S10 → Step S11 → Step S12 → Return That is, the power boost flag FLG is set to FLG = 1, and the boost control is started.

  Then, the short-circuit flag is turned ON from the next activation, and the short-circuit flag is turned ON → OFF at time t2 in FIG. 8, but since FLG = 1, step S1 → step S2 → step in the flowchart of FIG. The flow from S14 → step S10 → step S11 → step S12 → return is repeated. That is, the boost control is maintained.

  Then, at time t3 before the end of the boost control, when the short circuit flag is turned OFF → ON due to noise and the short circuit flag is received by communication, in the flowchart of FIG. 4, step S1 → step S2 → step S3 → It progresses to step S9-> step S10-> step S11-> step S12-> return. That is, in step S9, the counter value indicating the duration of the boost control is reset, and the duration is extended by re-counting the down count to maintain the boost control.

  Then, at time t4 before the end of the boost control, this time, when the short circuit flag is turned OFF → ON due to a short circuit, and the short circuit flag is received by communication, similarly, in the flowchart of FIG. The process proceeds from step S2, step S3, step S9, step S10, step S11, step S12, and return. That is, in step S9, the counter value representing the duration of the boost control is reset, the duration is extended by recounting the down count, and the boost control is maintained until time t5 when the counter value becomes zero.

In other words, in order to reliably determine the short-circuit current, a certain amount of time is required as described above, but this time it is necessary to operate early so as not to drop the voltage of the VDC / TCS / ABS unit. Therefore, the boost control is started only by receiving the short circuit flag once.
At this time, the duration of the boost control (= counter value) is the time until the short circuit current is determined (time t2 to time t3 in FIG. 7) and the time until the power is cut off by the interruption relay 22 (in FIG. 7). The total time of time t3 to time t4). Incidentally, since the duration of this boost control can be specified in advance including variations, a predetermined counter value is set.

In general, when detecting an abnormality, diagnosis is started when a certain threshold value is exceeded. In this case, the diagnosis is started when a current equal to or higher than the set current set on the electric booster 2 side is detected, but the diagnosis is stopped when the current is lower than the set current.
When a short circuit is detected on the electric booster 2 side, the boost control is first started on the electrohydraulic circuit 3 side using a short circuit flag from the electric booster 2 side regardless of noise or short circuit. The reason for doing this is because early boosting is required as described above.

  Then, every time the short circuit flag is received, the counter value is reset, and the counter value is again returned to a value corresponding to the duration of the boost control. This is because if the counter value is not reset, boosting may end before the short circuit is interrupted.

  As described above, there are two advantages to resetting the counter value. The first advantage is that the boosting battery 10a is a circuit power supply unit due to frequent ON / OFF of the boosting circuit 10 due to noise. It is possible to reduce the burden on. The second advantage is that the boosting can be reliably continued on the electrohydraulic circuit 3 side without fail until the short circuit is cut off without being affected by the influence of noise.

Next, the effect will be described.
In the electric vehicle power supply device according to the first embodiment, the following effects can be obtained.

(1) A power supply line 5 is provided in parallel from the vehicle power supply 1, and a plurality of load units (electric booster 2, electrohydraulic circuit 3, general load 4) are connected to each of the parallel power supply lines 5. In the device (vehicle power supply device),
First load unit control means (controller 21) for detecting a short circuit in which an excessive current flows in the first load unit (electric booster 2) among the plurality of load units (electric booster 2, electric hydraulic circuit 3, general load 4). When,
When short-circuit information (short-circuit flag) is input from the first load unit control means (controller 21), a boost command for boosting the voltage of the normal second load unit (electric hydraulic circuit 3) to at least the minimum operating voltage is boosted. Second load unit control means (VDC / TCS / ABS controller 7) for outputting to the circuit 10,
Equipped with.
For this reason, when a short circuit occurs in any of a plurality of load units (electric booster 2, electrohydraulic circuit 3, general load 4), normal operation of the load unit can be ensured without causing an increase in cost. .

(2) The first load unit control means (controller 21) outputs short-circuit information (short-circuit flag) and starts a short-circuit diagnosis when the current exceeds a preset set current, and sets a predetermined diagnosis time. If the current is equal to or higher than the set current even after the lapse of time, the short circuit diagnosis is confirmed and the short circuit portion is electrically cut off.
For this reason, in addition to the effect of (1), the boost control that makes the voltage of the second load unit (electric hydraulic circuit 3) equal to or higher than the minimum operating voltage is limited from the input of the short-circuit information (short-circuit flag) to the cutoff of the short-circuit current. It is possible to ensure the normal operation of the load unit by executing it for a predetermined period.

(3) The second load unit control means (VDC / TCS / ABS controller 7) short-circuits the boost command output to the booster circuit 10 with the minimum operating voltage of the second load unit (electric hydraulic circuit 3). Is set based on the power supply voltage from the vehicle power supply 1 at the time of occurrence of the above.
For this reason, in addition to the effects of (1) and (2), the second load is set so that it does not exceed the maximum operating voltage of the second load unit (electric hydraulic circuit 3) as in the case of uniform boosting. The load on the unit (the electrohydraulic circuit 3) can be reduced, and necessary boosting can be reliably performed when necessary.

(4) When the second load unit control means (VDC / TCS / ABS controller 7) receives short-circuit information (short-circuit flag) once from the first load unit control means (controller 21), the second load unit control means Boosting of the (electric hydraulic circuit 3) is started.
For this reason, in addition to the effects (1) to (3), it is possible to reliably prevent the load unit (the electrohydraulic circuit 3) whose operation is to be ensured from becoming a voltage equal to or lower than the minimum operating voltage.

(5) When the second load unit control means (VDC / TCS / ABS controller 7) starts boosting the second load unit (electric hydraulic circuit 3), at least a predetermined time from which the short-circuit current is cut off. Continue boosting.
For this reason, in addition to the effects (1) to (4), the voltage of the load unit (electric hydraulic circuit 3) for which the operation is to be ensured is minimized until the short-circuit current is interrupted after the short-circuit information (short-circuit flag) is input. It can be ensured above the operating voltage.

(6) Each time the second load unit control means (VDC / TCS / ABS controller 7) receives short-circuit information (short-circuit flag) from the first load unit control means (controller 21), the second load unit (electric motor) The pressurization duration time of the hydraulic circuit 3) is reset, and the measurement of the pressurization duration time is started again.
For this reason, in addition to the effects of (1) to (5), even when false detection of short-circuit current due to noise and correct detection of short-circuit current due to short-circuit are mixed, the voltage is surely boosted for the necessary time. be able to.

(7) The first load unit is an electric booster 2 that has an assist motor (three-phase motor 24) and assists the pedal depression force by the driver with motor torque during braking.
The second load unit is an electrohydraulic circuit 3 that includes an oil pump motor 31 and stabilizes vehicle behavior by suppressing side slip by driving force control independent of four wheels during traveling.
For this reason, in addition to the effects (1) to (6), when a short circuit occurs on the electric booster 2 side of the electric booster 2 and the electric hydraulic circuit 3 which are load units of the same braking system, the effect of the short circuit is affected by the electric hydraulic pressure. The normal operation of the electrohydraulic circuit 3 that stabilizes the vehicle behavior can be ensured without reaching the circuit 3.

  The second embodiment is an example in which a boost command is determined again when the occurrence of a short circuit is confirmed.

  First, the configuration will be described.

FIG. 9 is a flowchart illustrating the flow of the boost control process executed by the VDC / TCS / ABS controller 7 in the electric vehicle power supply apparatus according to the second embodiment. Hereinafter, each step of FIG. 9 will be described.
In addition, since each step of step S21-step S34 of FIG. 9 respond | corresponds to each step of step S1-step S14 of FIG.

  In step S35, following reception of the short-circuit flag in step S21, it is determined whether or not the short-circuit flag is ON. If Yes (short circuit flag = ON), the process proceeds to step S38. If No (short circuit flag = OFF), the process proceeds to step S36.

  In step S36, following the determination that the short-circuit flag = OFF in step S35, it is determined whether or not the count CNT representing the duration of the short-circuit flag ON is CNT> 0. If Yes (CNT> 0), the process proceeds to step S37. If No (CNT = 0), the process proceeds to step S22.

  In step S37, following the determination that CNT> 0 in step S36, the count CNT is set to CNT = 0, and the process proceeds to step S22.

  In step S38, following the determination that the short-circuit flag = ON in step S35, the count CNT representing the duration of the short-circuit flag ON is added by “+1”, and the process proceeds to step S39.

In step S39, following the count addition in step S38, it is determined whether or not the count CNT is CNT ≧ X (set value). If yes, the process proceeds to step S24. If no, the process proceeds to step S22.
In addition, since the other structure in Example 2 is the same as that of Example 1, illustration and description are abbreviate | omitted.

Next, the operation will be described.
As explained in Example 1, the short-circuit flag due to noise changes from OFF to ON and then turns OFF in a short time. However, the short-circuit flag due to short circuit changes from OFF to ON and then turns ON. continue. Therefore, in the case of the second embodiment, when the short circuit flag is changed from OFF to ON due to a short circuit, the flow proceeds from step S35 to step S38 to step S39 to step S22 in the flowchart of FIG. 9 from the next control cycle. Is repeated. When it is determined in step S39 that CNT ≧ X, the process proceeds from step S39 to step S24 → step S25 → step S26 → step S28.

  That is, when information indicating a short circuit (short circuit flag = ON) is continuously received for a predetermined time (CNT ≧ X), a boost command to be output to the boost circuit 10 is sent to the minimum operating voltage of the electrohydraulic circuit 3 and the vehicle at that time. It is set again based on the power supply voltage from the power supply 1.

As a result, immediately after the short-circuit flag is switched from OFF to ON due to noise, the short-circuit flag is switched from OFF to ON due to a short circuit. A boost command to be output to the circuit 10 can be determined.
That is, if the boost command determined at the time when the short-circuit flag is changed from OFF to ON due to noise (when there is no voltage drop), the boost may become insufficient. However, when it is confirmed that a short circuit has occurred (when a voltage drop occurs), the voltage of the electrohydraulic circuit 3 becomes lower than the minimum operating voltage by determining a boost command to be output to the booster circuit 10 again. Can be reliably prevented.
Since other operations are the same as those of the first embodiment, description thereof is omitted.

Next, the effect will be described.
In the electric vehicle power supply apparatus according to the second embodiment, the following effects can be obtained.

(8) The second load unit control means (VDC / TCS / ABS controller 7) indicates a short circuit after receiving short circuit information (short circuit flag OFF → ON) from the first load unit control means (controller 21). When information (short-circuit flag = ON) is continuously received for a predetermined time, a boost command to be output to the booster circuit 10 is sent to the minimum operating voltage of the second load unit (the electrohydraulic circuit 3) and the vehicle power supply at that time. The power supply voltage from 1 is set again.
For this reason, in addition to the effects (1) to (7) of the first embodiment, immediately after the occurrence of a short-circuit current due to noise, if a short-circuit current due to a short-circuit occurs, the voltage must be surely increased to the minimum operating voltage or higher. Can do.

  As mentioned above, although the vehicle electric power supply apparatus of this invention has been demonstrated based on Example 1 and Example 2, it is not restricted to these Examples about concrete structure, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention according to the paragraph.

  In the first and second embodiments, the example in which the electric booster 2 is the first load unit and the electric hydraulic circuit 3 is the second load unit has been described. However, the first load unit and the second load unit are not limited to these, and any load unit may be used as long as it is a vehicle power source load unit.

  In the first and second embodiments, the configuration of the vehicle power source in an electric vehicle such as a general hybrid vehicle or an electric vehicle is shown. This vehicle power supply (DC / DC converter + lead battery) has a sufficient capacity at present, but in the future, there is a possibility that a small capacity power supply will be installed from the viewpoint of cost. In other words, the present invention can be regarded as a statement that a reliable and inexpensive method can be provided even in such a small-capacity power supply system.

  In the first and second embodiments, the example of the power supply device mounted on the electric vehicle is shown. However, it can also be applied to a power supply device mounted on a gasoline vehicle. In the case of this gasoline vehicle, the vehicle power source is a combination of an alternator and a lead battery.

  In Examples 1 and 2, an electric booster that directly boosts the hydraulic pressure with a three-phase motor is shown. However, the electric booster may be one that artificially creates a negative pressure with a pump and boosts it, or may be one in which a necessary pressure is stored in an accumulator and released.

  In the first and second embodiments, the boost command is set based on the minimum operating voltage and the recording voltage at that time. However, in setting the boost command, a temperature condition may be added in addition to the voltage condition. In this case, it is considered that the accuracy is further improved.

  In Examples 1 and 2, an example in which the occurrence of a short circuit is detected by a current value is shown. However, depending on the system, it is also possible to detect a short circuit based on the rotation status of the motor, the relationship between the pedal stroke and hydraulic pressure, and the like.

1 Vehicle power supply 2 Electric booster (first load unit)
3 Electric hydraulic circuit (second load unit)
4 General load (load unit)
5 Power line 7 VDC / TCS / ABS controller (second load unit control means)
10 Booster circuit 21 Controller (first load unit control means)

Claims (8)

In the vehicle power supply device in which a power supply line is provided in parallel from the vehicle power supply, and a plurality of load units are connected to each of the parallel power supply lines.
First load unit control means for detecting a short circuit in which an excessive current flows in the first load unit among the plurality of load units;
Second load unit control means for outputting, to the booster circuit, a boost command for boosting the voltage of the normal second load unit to at least the minimum operating voltage when short-circuit information is input from the first load unit control means;
A vehicle power supply device comprising: The vehicle power supply device according to claim 1,
The first load unit control means outputs short-circuit information and starts short-circuit diagnosis when the current exceeds a preset set current, and the current is not less than the set current even after a predetermined diagnosis time has elapsed. And confirming the short circuit diagnosis and electrically cutting off the short circuit part. In the vehicle power supply device according to claim 1 or 2,
The second load unit control means sets a boost command to be output to the boost circuit based on a minimum operating voltage of the second load unit and a power supply voltage from the vehicle power supply when a short circuit occurs. A power supply device for a vehicle. In the vehicle electric power supply device according to any one of claims 1 to 3,
When the second load unit control means receives short-circuit information once from the first load unit control means, the second load unit control means starts boosting the second load unit. In the vehicular power supply device according to any one of claims 1 to 4,
When the boosting of the second load unit is started, the second load unit control means continues the boosting from the start until at least a predetermined time during which the short-circuit current is interrupted. In the vehicular power supply device according to any one of claims 1 to 5,
The vehicle, wherein the second load unit control means resets the boosting duration of the second load unit every time it receives short circuit information from the first load unit control means, and measures the boosting duration again. Power supply equipment. In the vehicle power supply device according to any one of claims 1 to 6,
The second load unit control means receives a short-circuit information from the first load unit control means, and then receives a boost command to be output to the boost circuit when receiving information indicating a short-circuit for a predetermined time. A vehicle power supply device, which is set anew based on a minimum operating voltage of the load unit and a power supply voltage from the vehicle power supply at that time. In the vehicle electric power supply device according to any one of claims 1 to 7,
The first load unit is an electric booster that has an assist motor and assists a pedaling force by a driver with a motor torque during braking,
The vehicle power supply apparatus according to claim 1, wherein the second load unit is an electrohydraulic circuit that has an oil pump motor and that stabilizes the vehicle behavior by suppressing side slip by driving force control independent of four wheels during traveling.