JP3536505B2 - Power supply for electric vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts the voltage of a main power supply to supply electric loads having different rated voltages, such as electric equipment and control circuits, in addition to a main power supply for supplying a drive motor. The present invention relates to a power supply device for an electric vehicle having a plurality of sub power supply systems.

[0002]

2. Description of the Related Art A driving motor is mounted on an electric vehicle. In order to increase the driving output, a driving motor having a high voltage rating is used. Accordingly, a high-voltage (eg, about 100 V to about 300 V) battery is used as a main power supply for driving the driving motor.

However, other electric devices mounted on electric vehicles often use existing devices for internal combustion engine vehicles in order to reduce costs. Their rated voltages are not necessarily the same as shown below. Lighting electrical components: 12V or 24V Power system electrical components (air conditioning compressors, power steering pumps): Approx. 50 to 100V Control devices (travel control devices, etc.): 12V or 24V Other devices (device cooling pumps, cooling fans) …
Each rated voltage

[0004] Therefore, the electric vehicle power supply device includes, in addition to the main power supply for supplying power to the drive motor, several sub-converters for converting the voltage of the main power supply into voltages corresponding to the respective rated voltages by a voltage converter. And a power supply system. These sub-power supply systems are linked with each other at the timing of start-up, cut-off, etc., but operate in other respects without any relation to one another.

[0005]

[Problems to be solved by the invention]

(Problem) In the power supply device for an electric vehicle as described above, if a failure (failure of the sub power supply system) occurs that a voltage of a certain sub power supply system is not supplied for some reason, the sub power supply The operation of the electric load connected to the system is stopped, and some operational driving performance is lost, resulting in a dangerous state for driving operation.However, conventionally, there is no alarm to notify that, and in response to the above loss There was a problem that no safety measures were taken.

(Explanation of Problems) For example, if the auxiliary power supply system supplying power to the power steering fails for some reason during traveling, the power steering suddenly stops working. However, since the other auxiliary power supply systems are normal, other electric devices such as the control device operate normally, and the vehicle runs at a speed corresponding to the depression of the accelerator pedal. Accordingly, the traveling speed is accelerated as usual even though the steering wheel operation is heavy and slightly delayed, and the driving operation becomes dangerous. Conventionally, failure detection, backup, etc. were performed for individual electric devices and devices, but no alarm or safety measures were taken for the failure of the sub power supply system. However, there is room for the danger described above. An object of the present invention is to solve such a problem.

[0007]

In order to solve the above-mentioned problems, according to the present invention, a main power supply for supplying power to a driving motor controlled by a driving motor control device, and the driving motor have a rated voltage. A power supply device for an electric vehicle including a plurality of sub-power supply systems configured by voltage converters for converting the voltage of the main power supply to voltages corresponding to the various rated voltages in order to supply power to various different electric loads. Voltage detecting means for detecting the voltage of the sub-power supply system,
Alarm means for alarming that the sub-power supply system has failed; and an operating power supply for converting voltages of the plurality of sub-power supply systems and supplied by a diode OR connection, based on a voltage detection signal from the voltage detection means. secondary power system determines whether the failure, when it is determined that the failure is in response to the sub-power supply of the failure
The alarm and the driving mode are set in a predetermined manner.
The warning means and the drive so as to regulate output to the
A failure alarm device that issues a signal to each of the motor control devices is provided.

[0008] The manner of alarming by the alarm means and the manner of regulating output to the drive motor can be individually determined in advance in accordance with the failed auxiliary power supply system.
In addition, a limited traveling means for restricting the output to the driving motor to such an extent that forward and backward movement at a low speed is possible is provided, and the failure for restricting the output to the driving motor when the auxiliary power supply system fails is provided. The signal from the alarm device may be issued to the limited traveling means instead of the drive motor control device.

(Summary of operation to be solved) Voltages of a plurality of sub power supply systems obtained by converting voltages of a main power supply are detected by voltage sensors. The voltage detection signal is input to the failure alarm device to determine which sub power supply system has failed. If any of the sub power supply systems fails, an alarm is issued by an alarm means and the output to the drive motor is regulated for safety. The method of alarming and the method of output control are determined in advance in accordance with the failed sub-power supply system. As a result, it is possible to perform an alarm or output restriction according to the importance of the electric load connected to the failed sub power supply system.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a power supply device for an electric vehicle according to the present invention. In FIG.
1 is a main power supply, 2 is a failure alarm device, 2-1, 2-2, 2-
3 is a counter, 3 is a drive motor control device, 4 is an alarm means, 5 is an accelerator pedal sensor, 6 is a selector switch, 7 is a drive motor, 8 to 13 are voltage converters,
4 to 16 are diodes, 17 is a first sub power supply, 18 is a second
An auxiliary power supply, 19 a third auxiliary power supply, 20 a first voltage sensor, 2
1 is a second voltage sensor, 22 is a third voltage sensor, and 23 is limited travel means.

First, the configuration will be described. Main power supply 1
Is a high voltage sufficient to drive the drive motor 7 (for example, about 1
00 to 300 V) and connected to the drive motor control device 3 and the voltage converters 8 to 10. The voltage converter 8 is a converter that converts the voltage of the main power supply 1 to the voltage V ₁ of the first sub power supply system. The output of the voltage converter 8 is applied to the first sub power supply (battery) 17 to charge and drive the power supply. Is supplied to the motor control device 3. The driving motor control device 3 is a first auxiliary power supply system load, and the supplied voltage V ₁ is used as a power source for operating a control circuit and the like in the driving motor control device 3.

The voltage converter 9 is a converter for converting the voltage of the main power supply 1 to the voltage V ₂ of the second sub power supply system, and its output is applied to the second sub power supply (battery) 18 to charge it. At the same time, it is supplied to a second auxiliary power supply system load (eg, a lighting device, an air conditioner) not shown. The voltage converter 10 is a converter for converting the voltage of the main power supply 1 into the voltage V ₃ of the third sub power supply system. The output of the voltage converter 10 is applied to a third sub power supply (battery) 19 to charge the same and charge the power. Not supplied to the third auxiliary power supply system load (eg, a brake booster, a power steering device).

The drive motor control device 3 is a device for controlling the rotation of the drive motor 7. The drive motor control device 3 includes an accelerator signal from an accelerator pedal sensor 5, a selector switch 6, and the like.
A driving operation signal such as a running range signal from the controller is input, and an output is supplied to the driving motor 7. In addition, one of the outputs from the failure alarm device 2 (an output regulation signal, which will be described later in detail) is input to the drive motor control device 3. Note that, as described above, the first sub-power supply 17 is connected to the drive motor control device 3 as an operation power supply.

First voltage sensor 20, second voltage sensor 2
The first and third voltage sensors 22 are provided so as to detect the voltages of the first to third sub-power supply systems, respectively, and detection signals from them are input to the failure alarm device 2. The failure alarm device 2
A device including a CPU, a memory, and the like, having an information processing function. The device determines whether each sub-power supply system is normal based on a detection signal from each voltage sensor. And an output restriction signal for restricting the output to the drive motor 7 to the drive motor control device 3. The counters 2-1 to 2-3 provided in the failure alarm device 2 are counters for determining abnormality of the first to third sub-power supply systems, respectively.

The limited traveling means 23 is an example of another means for regulating the output to the drive motor 7. When this is provided, when regulating the output to the drive motor 7,
Instead of issuing an output regulation signal to the drive motor control device 3 to regulate the output to the drive motor 7, a signal is issued to the limited traveling means 23 to regulate the output to the drive motor 7. Details will be described later with reference to FIGS.

As the warning means 4, for example, a warning lamp is used. Warning lamps are
(3) A red lamp is used to alert the failure of the sub-power supply system, and a yellow lamp is used to alert the failure of the second sub-power supply. They can be provided individually according to the importance.

The voltage converters 11 to 13 are converters for generating voltages for operating the failure alarm device 2 and the alarm means 4. These outputs are supplied to the failure alarm device 2 and the alarm means 4 via a so-called diode OR connection circuit using diodes 14 to 16. With such a supply, if at least one sub power supply system is normal, the failure alarm device 2 and the alarm means 4
Can be operated.

Next, the operation of the electric vehicle power supply device shown in FIG. 1 will be described. When a driver operates an accelerator pedal and a selector (not shown) and signals from the accelerator pedal sensor 5 and the selector switch 6 are input to the drive motor control device 3, the drive motor 7 is controlled in accordance with the signals. If and failure second sub-power system for some reason, when the voltage V ₂ is not out, informing the fault alarm unit 2 second voltage sensor 21 detects the fact. In the failure alarm device 2, since the failure is instantaneous and may return to normal immediately, a predetermined process (explained in FIG. 4) for excluding such a case is performed, and Or abnormal.

If it is determined that there is an abnormality, a signal is sent to the alarm means 4 to give an alarm, and a signal is sent to the drive motor control device 3 so that the drive motor 7 is subjected to an output control measure for ensuring safety. Let me take. This output restriction measure can be determined according to the importance of the electric load whose operation has been stopped due to the power failure. In an electric vehicle, all functions (drive, steering, brake boost, etc.) depend on power supply from one of the power supply systems, so which function is lost if any sub-power supply system fails Can be easily and reliably known. Therefore, it is possible to predict what kind of danger condition will occur in the driving operation. If appropriate warnings and output restrictions are determined in advance in accordance with the danger condition, safety is further ensured.

For example, the first auxiliary power supply system load is a drive motor control device 3, the second auxiliary power supply system load is a lighting device, an air conditioner, and the like, and the third auxiliary power supply system load is a brake booster.
In the case of a power steering device or the like, the method of alarming and the output control measures for the drive motor 7 can be determined in advance as follows according to the failed power supply system.

(1) When the first sub-power supply system fails (← drive motor control device) Warning: Lights a red warning lamp Output control measures: Issues a drive interruption command signal to the drive motor control device 3 (2) When the second sub-power supply system fails (← light, air-conditioning) Warning: Turns on the yellow warning lamp Output control measures: Issues a limited travel command signal to the drive motor control device 3 (here, "Limited run"
(This refers to running at a low speed that allows forward and backward movements.) (3) When the third sub-power supply system fails (← brake, power steering) Warning: Red warning lamp lighting output regulation Measures: Issue a limited travel command signal to the drive motor control device 3.

FIG. 2 is a diagram showing an example of the limited traveling means 23 in FIG. The reference numerals correspond to those in FIG. 1, 5-1 is a movable contact, 24 is a normally closed relay, 24-1 is a relay coil, 24-2 is a relay contact, and 25 is a resistor. The accelerator pedal sensor 5 has a potentiometer structure, and the movable contact 5-1 is moved according to the amount of depression of the accelerator pedal. The voltage of the movable contact 5-1 is input to the drive motor control device 3 as an accelerator signal _Sig . R ₁ is the resistance value of the entire potentiometer,
₂ is a resistance value of the resistor 25, and _VA is a voltage value applied to the whole.

A resistor 25 is connected in series with the accelerator pedal sensor 5.
And both ends thereof are short-circuited by a normally closed relay contact 24-2. The relay coil 24-1 is connected to the failure alarm device 2, and when a failure is alarmed, a current flows and is energized. When no current is flowing through the relay coil 24-1, the relay contact 24-2 is on and the resistor 25 is short-circuited. When a current flows, the relay contact 24-2 is turned off, and the resistor 25 is connected in series with the accelerator pedal sensor 5.

FIG. 3 is a diagram showing the output of the accelerator pedal sensor. The reference numerals correspond to those in FIG. The horizontal axis is the accelerator pedal depression amount, and the vertical axis is the accelerator pedal sensor output (that is, the accelerator signal S _ig ). The position of the movable contact 5-1 changes according to the accelerator pedal depression amount. A straight line a indicates a change in the accelerator pedal sensor output when the normally closed relay 24 is not energized (relay contact 24-2 is on). In this case, since the resistor 25 is short-circuited, the voltage obtained by dividing the voltage _VA at the position of the movable contact 5-1 is the accelerator pedal sensor output.
The maximum value is _VA .

A straight line B indicates a change in the accelerator pedal sensor output when the normally closed relay 24 is energized (relay contact 24-2 is off). In this case, since the resistor 25 is connected in series to the accelerator pedal sensor 5, the divided voltage at the position of the movable contact 5-1 in those series-connected bodies is the accelerator pedal sensor output. The maximum value is R ₁ V _A / (R ₁ + R ₂ ). That is, limited to the normally closed relay 24 of the traveling means 23, when the current from the fault alarm unit 2 was shed also depress the maximum accelerator pedal, low R ₁ much than if an accelerator pedal sensor output of the normal V _A / (R ₁ + R ₂ ). As a result, the output to the drive motor 7 is suppressed, and the limited travel is performed.

Next, the power supply failure alarm processing operation according to the present invention will be described with reference to the flowchart of FIG. This operation is mainly performed by the failure alarm device 2. Note that represents the counter value of the counter 2-1 to 2-3 Fig. 1, in CNT _1, CNT _2, CNT ₃ respectively. The magnitudes of the set values K _{1 to} K ₄ appearing in the flowchart are 0 <K ₁ , 0 <K ₂ , 0 <K ₃ , 0 <K
₄ ≦ MAX.

Step 1: An initial value is set in the counter. That is, the values of CNT ₁ , CNT ₂ , and CNT ₃ are set to 0. Step 2: first voltage sensor 20 to 22, it reads the detection voltage V ₂₀ ~V ₂₂ of the voltage of each sub-power supply system. Step 3: detected voltage V from first voltage sensor 20
_20, examine whether the set value K ₁ below. The value of K ₁ is previously set to a voltage value that is being lowered to below as the voltage of the first sub-power system trouble.

[0028] If step 4 ... set value K ₁ or less, the counter value CNT ₁ is small whether investigate than the maximum value MAX. When the counter 2-1 is configured by a binary memory, if the counter value has reached the maximum value MAX, if 1 is added in the next step 5, the carry is increased, and the value is expressed in the memory. Value returns to 0. In order to prevent such a situation, the process of step 4 is performed. If the value is not smaller than the maximum value MAX, step 5 is bypassed and the process proceeds to step 8.

Step 5: If the counter value CNT ₁ is still smaller than the maximum value MAX, 1 is added. That is,
The detected voltage V ₂₀ of the first sub-power system is the set value K ₁ or less (abnormal voltage value), the counter value CNT ₁ is still the maximum value MA
If it is smaller than X, 1 is added. Step 6: The detection voltage V ₂₀ of the first sub power supply system is set to the set value K ₁
If it is larger, it is checked whether the counter value CNT ₁ is 0 or not. When the counter 2-1 is configured by a binary memory, if the counter value is 0, if 1 is subtracted in the next step 7, the digit is lowered, and the value represented by the memory is obtained. Becomes the maximum value MAX. In order to prevent this from happening, perform the processing in step 6,
If 0, the process goes to step 8 bypassing step 7.

Step 7: If the counter value CNT ₁ is not 0, 1 is subtracted. That is, a first detection voltage V ₂₀ of the sub-power supply system is larger than the set value K ₁ (normal voltage value), the counter value CNT ₁ is not zero, subtracts 1. Step 8-12: second detection voltage V ₂₁ of the sub-power supply system, the counter value CNT _2, the same processing as step 3-7. The setting value K ₂ is set to a voltage value of trouble is being lowered to below as the voltage of the second sub-power supply system. Step 13-17 ... third detection voltage V ₂₂ of the sub-power supply system, the counter value CNT _3, the same processing as step 3-7. The setting value K ₃ is set to a voltage value of the third being reduced to below as the voltage of the sub power system trouble.

[0031] Step 18 ... counter value CNT ₁ is, see if has become a set value K ₄ or more. As can be understood from steps 5 and 7, the counter value CNT ₁ is decremented by one each time the flow of the flowchart of FIG. 4 is performed once if the voltage of the first sub power supply system is determined to be normal, and determined to be abnormal. If done, one is added. Thus, towards the number of times it is determined that an abnormality, becomes larger than the number of times it is determined to be normal, the counter value CNT ₁ is slide into increased. Set value K _4, when the number of times it is determined that an abnormality which position the number of times larger, the voltage drop of the first sub-power system is set as a guide that can be determined to be other than instantaneous You. Steps 19 and 20: counter values CNT ₂ and CNT
_3, examine whether and has a set value K ₄ or more. This has the same purpose as step 18.

Step 21: Counter values CNT ₁ and CN
If either T ₂ or CNT ₃ is equal to or greater than the set value K ₄ ,
Come to this step. This means that the voltage of one of the sub-power supply systems has become abnormal, and the alarm and output regulation operation are performed in a manner predetermined according to the abnormal sub-power supply system. For example, in step 19, the counter value CNT ₂
If There came to step 21 in that K ₄ or more, the second sub-power supply system (lighting, air-conditioning supply) from a failure of, the following alarms are determined in advance in response thereto, the output regulation I do. Alarm: Turns on the yellow warning lamp Output control measures: The drive motor control device 3 that issues a limited travel command signal to the drive motor control device 3 suppresses the output to the drive motor 7 to the extent that the vehicle travels in a limited manner. I do. If the limited travel means 23 as shown in FIG. 2 is provided,
A current flows from the failure alarm device 2 to the relay coil 24-1.

Step 22: Counter values CNT ₁ and CN
If neither T ₂ nor CNT ₃ is equal to or greater than the set value K ₄ , no alarm is issued and output to the drive motor 7 is not regulated because the voltages of all sub-power supply systems are normal.

In an electric vehicle, there are a plurality of sub power systems using a main power source as an energy source. If any sub power system fails, an electric load (eg, The power steering device stops operating, but the electric loads connected to the other auxiliary power supply systems still operate normally. In this case, the function of the vehicle driving operation becomes unbalanced and a dangerous state occurs. However, according to the present invention, as described above, the output to the driving motor is regulated so as to match the stopped electric load. The driving operation of the vehicle is guided to the safe side.

[0035]

As described above, in the electric vehicle power supply device of the present invention, the voltages of the plurality of sub power supply systems are detected by the voltage sensors, and the voltage detection signals are input to the failure alarm device. It is determined which sub-power supply system has failed.
If any of the sub power supply systems fails, a warning is issued by a warning means, and the output to the drive motor is regulated to ensure safety.
Since it is determined in advance according to the failed sub-power supply system, an appropriate alarm or output restriction can be performed according to the importance of the electric load connected to the failed sub-power supply system.

[Brief description of the drawings]

FIG. 1 is a block diagram of a power supply device for an electric vehicle according to the present invention.

FIG. 2 is a diagram showing an example of limited traveling means;

FIG. 3 is a view showing an output of an accelerator pedal sensor.

FIG. 4 is a flowchart for explaining a power system failure alarm processing operation according to the present invention;

[Explanation of symbols]

1: Main power supply, 2: Failure alarm device, 2-1, 2-2, 2-
DESCRIPTION OF SYMBOLS 3 ... Counter 3 ... Drive motor control device 4 ... Alarm means 5 ... Accelerator pedal sensor 5-1 ... Movable contact 6
... Selector switch, 7 ... Drive motor, 8-13 ... Voltage converter, 14-16 ... Diode, 17 ... First sub-power supply, 18 ... Second sub-power supply, 19 ... Third sub-power supply, 20 ... First voltage sensor , 21 ... second voltage sensor, 22 ... third voltage sensor, 23 ... limited traveling means, 24 ... normally closed relay, 24
-1 ... Relay coil, 24-2 ... Relay contact, 25 ... Resistance

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60L 1/00-3/12 B60L 7/00-13/00 B60L 15/00-15/42 H02H 7 / 00 H02H 7/20 H02J 7/00

Claims (1)

(57) [Claims] 1. A main power supply for supplying power to a drive motor controlled by a drive motor control device; and a voltage of the main power supply for supplying electric loads having different rated voltages from the drive motor. A power supply device for an electric vehicle comprising a plurality of sub power supply systems configured by a voltage converter that converts the voltage into a voltage corresponding to the various rated voltages, voltage detection means for detecting the voltage of the sub power supply system, Alarm means for alarming that the sub-power supply system has failed; and operating power supplied by converting the voltages of the plurality of sub-power supply systems by diode OR connection, based on a voltage detection signal from the voltage detection means. secondary power system determines whether the failure, when it is determined that failure, in response to the sub power supply that failure
Alarm and the drive mode in a manner previously determined individually.
The alarm means and the
A power supply device for an electric vehicle, comprising: a failure alarm device that emits a signal to each of the drive motor control devices.