JP2004088821A - Power controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power controller which requires no external timer. <P>SOLUTION: A relay control unit 34 turns on relays 18, 20, and 22 in such a procedure as prevents an in-rush current by an inrush limit resistor 24, to power-connect a high voltage battery 16 to a motor 12. A counter 36 counts the number of times of power connections. A connection limit 38 prohibits power connection action when a counter value of the counter 36 reaches a prescribed value. A cooling time setting part 42 sets heat release hours required for releasing the heat of the inrush limit resistor 24 based on the duration time of power connection. A cooling time timer 44 measures the elapsed time after ignition-off is inputted. A counter value correction part 40 corrects a counter value according to the heat release hours when a heat release time comes, thus completing the power control action. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power supply control device, and more particularly to a power supply control device for a power supply circuit having a high output power supply.
[0002]
[Prior art]
Electric vehicles and hybrid vehicles have a motor as a drive source and a high-voltage battery for supplying power to the motor, and a relay for shutting off power supply is provided between the high-voltage battery and the motor. Is provided. The power supply control device controls the relay to supply and cut off power. The high-voltage battery has a high voltage of, for example, 200 V DC. Therefore, if the high-voltage battery is suddenly connected to the motor, an instantaneous large current, that is, an inrush current flows, and there is a possibility that the relay may be broken. As a countermeasure against this, an inrush limiting resistor is provided, and at the start of power supply from the high-voltage battery to the motor, current is supplied through the inrush limiting resistor. In other words, the inrush limiting resistor converts the energy of the inrush current into thermal energy generated by itself, thereby preventing the breakdown of the relay and the like. However, when the connection between the high-voltage battery and the motor is repeatedly performed, the inrush limiting resistor repeatedly generates heat without an opportunity for heat radiation. For this reason, it is necessary to monitor the heat dissipation time of the inrush limiting resistor, estimate the temperature of the inrush limiting resistor, and then control the connection between the high-voltage battery and the motor.
[0003]
The inrush limiting resistor radiates heat even when the high-voltage battery and the motor are not connected, that is, when the vehicle stops and the power supply to the power control device itself stops and the control operation stops. Therefore, in order to monitor the heat dissipation time of the inrush limiting resistor while the control operation of the power supply control device is stopped, an external timer that can be used even when the control operation of the power supply control device is stopped is separately provided. It had to be set up and monitored.
[0004]
[Problems to be solved by the invention]
As described above, the conventional power supply control device needs to use an external timer that can be used even when the control operation of the power supply control device is stopped.
[0005]
Therefore, an object of the present invention is to provide a power supply control device that does not require an external timer.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a power supply control device according to the present invention controls a power supply circuit in which a battery and a load are connected via a relay and an inrush limiting resistor for limiting an inrush current from the battery to the load is provided. A power control device, a relay control unit that connects a battery and a load according to a power connection instruction input from the outside, and powers off the battery and the load according to a power disconnection instruction input from the outside; Connection limiting means for inhibiting the power connection when the counter value corresponding to the number of times of the power connection reaches a predetermined value, and a heat radiation time set for heat radiation of the inrush limiting resistor after the power-off instruction is input. And a counter value correcting means for correcting the counter value based on the heat release time after the lapse of time.
[0007]
According to the above configuration, after the heat dissipation time of the inrush limiting resistor has elapsed, the counter value is corrected based on the heat dissipation time, that is, the counter value is returned in response to the next power supply connection instruction, and then the power control is performed. The control operation of the device can be terminated. For this reason, even if the power supply of the power supply control device itself is turned off after the control ends, it is possible to respond to the next power supply connection instruction without having to separately provide an external timer for monitoring the heat radiation time while the power supply control device is turned off. Therefore, it is possible to suppress an increase in dark current due to the addition of an external timer, the addition of a dedicated circuit, and an increase in cost associated with the addition.
[0008]
Desirably, the counter value correction unit corrects the counter value based on the heat dissipation time and the duration of the power connection, and a heat dissipation time setting unit that sets the heat dissipation time based on the duration of the power connection, Is further provided.
[0009]
According to the above configuration, the heat dissipation time of the inrush limiting resistor is set in anticipation of the heat dissipation while the power connection is continued, so that it is possible to avoid an unnecessary long heat dissipation time. Therefore, it is possible to avoid unnecessarily securing the power supply of the power supply control device for the heat radiation time, thereby reducing power consumption.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 shows a preferred embodiment of a power supply control device according to the present invention, that is, a power supply circuit for supplying electric power to a drive source motor of an electric vehicle, and a power supply control device therefor. FIG.
[0012]
The power supply circuit 10 includes a motor 12 and a filter capacitor 14 as a vehicle drive source, a high-voltage battery 16 for supplying power to the motor 12, relays 18, 20, and 22 for connecting / disconnecting the high-voltage battery 16 and the motor 12. The inrush limiting resistor 24 is provided. The high-voltage battery 16 is a large-capacity battery of DC 200 V, for example. A voltmeter 26 is provided in parallel with the filter capacitor 14 and the motor 12, and the power supply control device 30 controls each of the relays 18, 20, and 22 based on the measurement value of the voltmeter 26.
[0013]
The power supply control device 30 is connected to a battery for a control device (not shown) which is different from the high-voltage battery 16. When power is supplied to the power supply control device 30 by a user's key operation, that is, when the ignition is turned on, the power supply control device 30 The control of the circuit 10 is started. Conversely, when the ignition is turned off, after performing a predetermined control operation, the power supply to the power supply control device 30 is also stopped, and unnecessary power consumption by the power supply control device 30 is avoided. The control device battery may be obtained from the high-voltage battery 16 by voltage conversion.
[0014]
Next, each unit in the power supply control device 30 will be described. The control unit 32 centrally manages each unit in the power supply control device 30 and has an external interface function. That is, when the ignition ON, which is the power supply connection instruction, is input from outside, the power supply control device 30 is started up and the power supply control is started. Further, when an ignition OFF, which is a power-off instruction, is input, a necessary operation is performed immediately before the end of the power control, and then the power supply to the power control device 30 itself is cut off. During a period in which the power control is not performed, that is, a period in which the ignition is OFF, the power to the power control device 30 itself is also cut off, and the power consumed inside the power control device 30 is suppressed as much as possible.
[0015]
When ignition ON is input to the control unit 32, the relay control unit 34 controls the relays 18, 20, and 22 to connect the positive electrode and the negative electrode of the high-voltage battery 16 to the motor 12. Thus, current is supplied to the filter capacitor 14 provided in parallel with the motor 12. The voltage of the high-voltage battery 16 is a high voltage, for example, DC200V. Therefore, if the motor 12 is suddenly connected to a low voltage state, a large current, that is, an inrush current flows instantaneously, and the contacts of the relays 18, 20, and 22 may be broken. Therefore, an inrush limiting resistor 24 is provided in series with the relay 20, and at the time of starting the power supply, the relays 18, 20, and 22 are turned on in a procedure that prevents the inrush current by the inrush limiting resistor 24. Is done.
[0016]
That is, when ignition ON is input, the relay control unit 34 first turns on the relay 22 provided on the negative electrode side of the high-voltage battery 16 and then turns on the relay 20 provided on the positive electrode side. At this time, an inrush current from the high voltage battery 16 to the motor 12 is suppressed by the inrush limiting resistor 24 connected in series with the relay 20. When the voltmeter 26 detects that a current is supplied from the high-voltage battery 16 and the voltage across the filter capacitor 14 has increased, the relay 18 provided in parallel with the relay 20 is turned on, and then the relay 20 is turned off. Thus, the output of the high-voltage battery 16 is transmitted to the motor 12 while suppressing the inrush current. When the power supply of the high voltage battery 16 and the motor 12 is cut off, the relay 18 and the relay 22 may be cut off simultaneously or one by one. In this way, the power supply connection / disconnection between the high-voltage battery 16 and the motor 12 is performed.
[0017]
The counter 36 counts the number of power connections. That is, a count value, which is the number of times of connection / disconnection between the high-voltage battery 16 and the motor 12 controlled by the relay control unit 34, is measured and output to the connection limit unit 38. When the power supply is connected, the inrush current is suppressed by the inrush limiting resistor 24, but as a result, the suppressed energy is released as heat by the inrush limiting resistor 24. Therefore, if the connection / disconnection of the power supply is repeated in a short time, the inrush limiting resistor 24 cannot radiate heat and its temperature rises excessively, and the inrush limiting resistor 24 itself or a resin component around the resistor or the like. May be destroyed.
[0018]
Therefore, the connection limiting unit 38, which is a connection limiting unit, limits the power supply connection operation based on the count value of the number of power supply connections in order to prevent the temperature of the inrush limiting resistor 24 from excessively increasing. That is, when the count value reaches a predetermined value, for example, 100 times, the connection operation of the power supply is prohibited.
[0019]
The counter value correction unit 40 corrects the counter value of the number of times of power connection under a predetermined condition. As described above, the counter value is used for estimating the temperature of the inrush limiting resistor 24. The inrush limiting resistor 24 is used only when the power supply is connected, and is not used in other time periods, for example, when the power supply connection is continued or the power supply is cut off. And the temperature drops. For example, the temperature rise of the inrush limiting resistor 24 by one power connection is 1 ° C., the heat radiation time required to lower the inrush limiting resistor 24 by 1 ° C. is 10 seconds, and the temperature rise allowable value of the inrush limiting resistor 24 is a normal temperature value + 100 ° C. In consideration of the above, the allowable value of the number of times of connection when the inrush limiting resistor 24 is repeatedly connected from the normal temperature value without the heat radiation time is 100 times.
[0020]
However, in a state in which the power connection is continued after the power connection is made, for example, in a state in which the vehicle is running, the rush limit resistor 24 radiates heat. Therefore, if the inrush limiting resistor 24 is connected at a temperature 90 ° C. higher than the normal temperature value, that is, in a state where the count value is 90 times, and the running state continues for 900 seconds or more, the inrush limiting resistor 24 is dissipated due to heat radiation during running. It will drop to room temperature. In this case, the counter value correction unit 40 may change the count value to zero. The running state is not always long, and the running may end in about 20 seconds, for example. In such a case, for example, the count value may be reduced by 1 every 10 seconds, and may be set as appropriate according to the use situation.
[0021]
The heat radiation of the inrush limiting resistor 24 is not limited to the time when the vehicle is running, and is also performed while the vehicle is stopped. However, in a state where the vehicle is stopped and the ignition is turned off and the power supply of the power supply control device 30 itself is turned off, it is not possible to measure the stop period of the vehicle, that is, the heat release time of the inrush limiting resistor 24. Therefore, in the present embodiment, when the ignition OFF is input from the outside, a cooling time for the inrush limiting resistor 24 is provided in advance before the power control is terminated, and after the cooling time has elapsed, the power control is terminated and the power control is terminated. The power of the device 30 is turned off. At this time, that is, at the end of the power control, the counter value correction unit 40 also corrects the count value corresponding to the cooling time. The setting of the cooling time and the modification of the counter value based on the cooling time will be described below.
[0022]
The cooling time setting unit 42, which is a cooling time setting unit, sets the cooling time according to the duration of the power connection. Since the inrush limiting resistor radiates heat even while the power connection is continued, the cooling time is desirably set according to the duration of the power connection. That is, if the duration of the power supply connection is long, for example, the duration exceeding 900 seconds in the above example, no cooling time is required because the rush limit resistor 24 has returned to the normal temperature value. Conversely, if the duration of the power connection is short and the rush limiting resistor 24 is not dissipating heat at all, a cooling time should be provided for at least 10 seconds, that is, only for the temperature that increases with one power connection. This enables the next power connection. As described above, the cooling time may be set in advance in consideration of the temperature rise at the time of the next power supply connection, and is appropriately set according to the configuration of the vehicle or the use situation.
[0023]
The cooling time timer 44 counts the cooling time after the ignition OFF is input. That is, the elapsed time since the ignition OFF is input is counted, and when the elapsed time reaches the cooling time set by the cooling time setting unit 42, the control unit 32 and the counter value correction unit 40 notify that the cooling time has elapsed. Output to The counter value correction unit 40 corrects the count value based on the cooling time. For example, when the cooling time of 100 seconds has elapsed, 10 times corresponding to 100 seconds are subtracted from the count value. On the other hand, the control unit 32 ends the power control by each unit in the power control device 30, and stops the power supply to the power control device 30 itself. Since the control operation of the power control device 30 is terminated after the cooling time of the inrush limiting resistor 24 is provided in this manner, the inrush limiting resistor 24 is set to the allowable temperature or less at the next control operation start of the power control device 30. Can be used at
[0024]
In the above-described embodiment, the control of the power supply circuit including the high-voltage battery and the vehicle drive motor has been described.However, the power supply control device according to the present invention includes a combination of another high-voltage battery and a high-voltage load, for example, It is also effective for controlling a power supply circuit in combination with an air conditioner device, a power steering device, or the like.
[0025]
【The invention's effect】
As described above, the present invention can provide a power supply control device that does not require an external timer.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an overall configuration of a power supply control device according to the present invention.
[Explanation of symbols]
34 relay control section, 38 connection limit section, 40 counter value correction section, 42 cooling time setting section.

Claims (2)

A battery and a load are connected via a relay, a power supply control device that controls a power supply circuit provided with an inrush limiting resistor that limits an inrush current from the battery to the load,
Relay control means for power-connecting the battery and the load in response to a power connection instruction input from the outside, and powering off the battery and the load in response to the power-off instruction input from the outside;
Connection restricting means for prohibiting the power connection when the counter value corresponding to the number of times of the power connection reaches a predetermined value,
After the power-off instruction is input, after the heat radiation time set for heat radiation of the inrush limiting resistor has elapsed, counter value correction means for modifying the counter value based on the heat radiation time,
A power supply control device having: The power supply control device according to claim 1,
The counter value correction unit corrects the counter value based on the heat dissipation time and the duration of the power connection,
Heat radiation time setting means for setting the heat radiation time based on the duration of the power connection,
A power supply control device further comprising:

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