Power supply control device, on-board control device, and power supply control method

Abstract

To provide a power supply control device, an in-vehicle control device, and a power supply control method that can detect abnormalities in power supply when a current value is small.SOLUTION: An individual ECU 11a controls the power supply via an electric wire W. A microcomputer 21 of the individual ECU 11a gradually increases the average value of the electric wire current values of the current flowing through the electric wire W. Each time the microcomputer 21 raises the average value of the electric wire current value, the microcomputer determines whether an abnormality has occurred in the power supply via the electric wire W on the basis of the temperature difference between the electric wire temperature of the electric wire W and the environmental temperature around the electric wire W.SELECTED DRAWING: Figure 2

Claims

1. A power supply control device that controls power supply via power lines, It includes a processing unit that performs processing, The aforementioned processing unit, The average value of the wire current flowing through the aforementioned wire is increased in stages. Each time the average value of the wire current increases, it is determined whether or not an abnormality has occurred in the power supply via the wire, based on the temperature difference between the wire temperature and the ambient temperature around the wire. A power supply control device, A switch is placed in the current path of the current flowing through the aforementioned wire, A switching circuit for switching the aforementioned switch on or off, Equipped with, A signal is input to the switching circuit. The switching circuit switches the switch on or off according to the input signal. The switching circuit, when the wire current value is greater than or equal to the current threshold, or when the temperature of the switch is greater than or equal to the switch temperature threshold, switches the switch to the OFF state regardless of the input signal, thereby transitioning the power supply state to the OFF state. The processing unit, after the power supply state transitions to the interrupted state, gradually increases the average value of the wire current from zero. Power supply control device.

2. The aforementioned processing unit, The wire current value is obtained, The temperature difference is calculated based on the acquired wire current value. Each time the average value of the wire current is increased, it is determined whether or not the aforementioned abnormality has occurred based on the calculated temperature difference. The power supply control device according to claim 1.

3. The processing unit is The switching circuit is made to perform PWM control to alternately switch the switch on and off. By gradually increasing the duty cycle of the PWM control, the average value of the wire current is increased step by step. The power supply control device according to claim 1 or claim 2.

4. The system includes a storage unit that stores multiple upper limit values ​​for the temperature difference, corresponding to multiple duty cycles related to the PWM control. Each time the average value of the wire current increases, the processing unit determines whether or not the abnormality has occurred based on whether or not the temperature difference exceeds the upper limit corresponding to the duty cycle of the PWM control performed by the switching circuit. The power supply control device according to claim 3.

5. Each time the average value of the wire current increases, the processing unit determines whether or not the abnormality has occurred based on the increase in the temperature difference caused by the increase in the average value of the wire current. The power supply control device according to claim 3 or claim 4.

6. The aforementioned processing unit, If the wire temperature is above the wire temperature threshold, the flow of current through the wire is interrupted. After the wire temperature reaches a temperature above the wire temperature threshold, the average value of the wire current is increased in stages. A power supply control device according to any one of claims 1 to 5.

7. An on-board control device for controlling the operation of a load, A receiving unit that receives instruction data instructing the operation or cessation of the load, Processing unit that executes the process and Equipped with, The aforementioned processing unit, The receiving unit controls the power supply to the load via the wire according to the instruction data it receives. The average value of the wire current flowing through the aforementioned wire is increased in stages. Each time the average value of the wire current is increased, it is determined whether or not an abnormality has occurred in the power supply via the wire, based on the temperature difference between the wire temperature and the ambient temperature around the wire. A switching circuit, which switches a switch located in the current path of the current flowing through the aforementioned wire on or off when a signal is input, switches the wire current value above a current threshold, or the temperature of the switch above a switch temperature threshold, to turn the switch off regardless of the signal input to the switching circuit, thereby transitioning the power supply state to a cutoff state, after which the average value of the wire current value is gradually increased from zero. In-vehicle control device.

8. A power supply control method via power lines, The steps include gradually increasing the average value of the wire current value of the current flowing through the aforementioned wire, Each time the average value of the wire current is increased, the step of determining whether or not an abnormality has occurred in the power supply via the wire is determined based on the temperature difference between the wire temperature and the ambient temperature around the wire. A switching circuit, which switches a switch located in the current path of the current flowing through the wire on or off when a signal is input, is used to switch the wire current value to the off state when the wire current value is greater than or equal to a current threshold, or when the temperature of the switch is greater than or equal to a switch temperature threshold, regardless of the signal input to the switching circuit, thereby transitioning the power supply state to an interrupted state, followed by a step of gradually increasing the average value of the wire current value from zero. A power supply control method performed by a computer.

Images