Failure detection circuit of charging device

Abstract

To provide a failure detection circuit of a charging device capable of checking whether or not a high voltage circuit is normally operated.SOLUTION: A failure detection circuit 1 of a charging device includes an AND circuit 12 and a first control unit 10. The AND circuit 12 determines a drive signal of the DC-DC circuit 13 based on a drive command value to a DC-DC circuit 13 input from outside and a drive permission signal to the DC-DC circuit 13. The first control unit 10 determines whether or not the drive signal output to the AND circuit 12 matches a predetermined value.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a failure detection circuit for a charging device.

Background Art

[0002] Patent Document 1 describes a technique for protecting a battery when an abnormality occurs in a charging circuit. In this technique, when the input voltage input from a DC power supply to the charging circuit is a fluctuation indicating an abnormal value, it is determined that there is an abnormality in the charging circuit, and the first power supply path or the second power supply path connecting the DC power supply and the charging circuit is cut off.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a vehicle, when stopping the power supply from an in-vehicle charger to a battery, a CPU (Central Processing Unit) that controls the operation of a high-voltage circuit stops the operation of the high-voltage circuit of the charger. If this CPU fails for some reason and cannot stop the operation of the high-voltage circuit, overcharging from the in-vehicle charger to the battery will occur. Therefore, in a vehicle, from the viewpoint of safety, even when the CPU fails, a circuit for stopping the high-voltage circuit is separately provided. For this reason, conventionally, the input power from the system and the output current to the battery are monitored, and when current flows during the operation confirmation of the forced stop circuit, it is determined that there is an abnormality.

[0005] However, in recent years, since the charging power has become large, even when the high-voltage circuit is in a stopped state when charging is stopped, input power may be input to the high-voltage circuit, and it has not been possible to determine whether it is in a stopped state or operating.

[0006] The present disclosure has been made in view of the above, and an object thereof is to provide a failure detection circuit for a charging device that can confirm whether a high-voltage circuit is operating normally.

Means for Solving the Problems

[0007] In order to solve the above-described problems and achieve the object, a failure detection circuit for a charging device according to the present disclosure is a failure detection circuit for a charging device, including a determination unit that determines and outputs a drive signal input to a power conversion circuit, and a determination unit that determines whether the drive signal output from the determination unit is correct. The determination unit determines the drive signal based on a drive command value for the power conversion circuit input from the outside and the drive permission signal for the power conversion circuit, and the determination unit determines whether the drive signal matches a predetermined value.

Advantages of the Invention

[0008] According to the present disclosure, there is an effect that it is possible to confirm whether the high-voltage circuit is operating normally.

Brief Description of the Drawings

[0009]

Figure 1

Mode for Carrying Out the Invention

[0010] Hereinafter, a failure detection circuit for a charging device according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the components in the following embodiments include those that can be replaced and are easy for those skilled in the art, or those that are substantially the same. In addition, each drawing referred to in the following description only schematically shows the shape, size, and positional relationship to the extent that the content of the present disclosure can be understood. That is, the present disclosure is not limited to only the shape, size, and positional relationship illustrated in each drawing.

[0011] 〔Configuration of Failure Detection Circuit〕 FIG. 1 is a block diagram showing a functional configuration of a failure detection circuit of a charging device according to an embodiment. The failure detection circuit 1 shown in FIG. 1 is an OBC (ON-BOARD CHARGER) used when charging a battery, and for example, converts a voltage (AC) from a charging stand into a voltage (DC) required for the battery. The failure detection circuit 1 includes a first control unit 10, a second control unit 11, an AND circuit 12, a DCDC circuit 13, and an insulation circuit 14.

[0012] The first control unit 10 communicates bidirectionally with a host control unit 100 composed of an ECU (Electronic Control Unit) provided in the vehicle via CAN (Controller Area Network) communication. The first control unit 10 is configured using a processor having a memory and hardware such as a CPU. The first control unit 10 receives a CAN communication signal (hereinafter simply referred to as "drive command") indicating a drive command value for driving the DCDC circuit 13 and a drive permission signal (hereinafter simply referred to as "CHEN signal") for permitting the drive of the DCDC circuit 13, which are input from the host control unit 100. The first control unit 10 outputs the drive command received from the host control unit 100 to the second control unit 11 via serial communication. Further, the first control unit 10 outputs the CHEN signal to the AND circuit 12 via a direct line electrically connecting the AND circuit 12 and the first control unit 10. Further, the first control unit 10 receives a drive signal output from the AND circuit 12 via a direct line electrically connecting the insulation circuit 14, which will be described later, and the first control unit 10. The first control unit 10 determines the correctness of the drive signal output from the AND circuit 12. Specifically, the first control unit 10 determines whether or not the drive signal output from the output side of the AND circuit 12 via the insulation circuit 14 matches a predetermined value (High / Low). In one embodiment, the first control unit 10 functions as a determination unit.

[0013] The second control unit 11 is configured by using a memory and a processor having hardware such as a CPU different from the first control unit 10. The second control unit 11 receives a drive command by serial communication input from the first control unit 10, and outputs the received drive command to the AND circuit 12.

[0014] The AND circuit 12 determines a drive signal to be input to the DCDC circuit 13 based on the drive command received from the second control unit 11 and the CHEN signal received from the first control unit 10 via a direct wire electrically connected to the first control unit 10, and outputs this drive signal to the DCDC circuit 13. Specifically, when the drive command is drive and the CHEN signal is drive permission, the AND circuit 12 outputs the drive signal to the DCDC circuit 13. On the other hand, when the drive signal is off and the CHEN signal is drive prohibition, the output of the drive signal is stopped. Also, on the output side of the AND circuit 12, a feedback circuit that feeds back the drive signal to the first control unit 10 via the isolation circuit 14 is formed. In one embodiment, the AND circuit 12 functions as a determination unit.

[0015] The DCDC circuit 13 converts a direct current (DC) input from the outside into a direct current (DC) corresponding to the battery based on the drive signal from the AND circuit 12 and outputs it. In one embodiment, the DCDC circuit 13 functions as a power conversion circuit.

[0016] One end of the isolation circuit 14 is electrically connected to the output side of the AND circuit 12 via a direct wire, and the other end is electrically connected to the first control unit 10 via a direct wire.

[0017] The fault detection circuit 1 configured as described above has the first control unit 10 determine whether the drive signal output from the output side of the AND circuit 12 via the insulation circuit 14 matches a predetermined value (High / Low). When the drive signal matches the predetermined value (High / Low), the first control unit 10 determines that a drive signal for operating the DCDC circuit 13 is being output, and outputs a drive signal indicating that the DCDC circuit 13 is operating normally during charging to the upper control unit 100 via CAN communication. On the other hand, when the drive signal does not match the predetermined value (High / Low), the first control unit 10 determines that a signal for operating the DCDC circuit 13 is not being output, and outputs a drive signal indicating that the DCDC circuit 13 is operating abnormally during charging to the upper control unit 100 via CAN communication. Thus, even if the CHEN signal input to the AND circuit 12 has failed (broken) on the permission side that permits the driving of the DCDC circuit 13, and even when the CHEN signal from the upper control unit 100 or the first control unit 10 is a drive inhibition command, the first control unit 10 can determine the correctness of the drive signal output from the AND circuit 12 based on the feedback drive signal from the AND circuit 12.

[0018] According to the above-described embodiment, when the drive signal of the first control unit 10 matches the predetermined value (High / Low), it is determined that a drive signal for operating the DCDC circuit 13 is being output, and a drive signal indicating that the DCDC circuit 13 is operating normally during charging is output to the upper control unit 100 via CAN communication. On the other hand, when the drive signal of the first control unit 10 does not match the predetermined value (High / Low), it is determined that a signal for operating the DCDC circuit 13 is not being output, and a drive signal indicating that the DCDC circuit 13 is operating abnormally during charging is output to the upper control unit 100 via CAN communication. Thereby, malfunction of the DCDC circuit 13 can be suppressed.

[0019] Further effects and modifications can be easily derived by those skilled in the art. The broader aspects of the present invention are not limited to the specific details and representative embodiments described and represented as above. Therefore, various changes are possible without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

[0020] As described above in detail some embodiments of the present application with reference to the drawings, these are examples, and the present invention can be implemented in other forms with various modifications and improvements based on the knowledge of those skilled in the art, starting from the aspects described in the disclosure column of the present invention.

Description of Reference Numerals

[0021] 1 Fault detection circuit 10 First control unit 11 Second control unit 12 AND circuit 13 DCDC circuit 14 Insulation circuit 100 Higher-level control unit

Claims

Claim 1 A failure detection circuit for a charging device, a determination unit that determines and outputs a drive signal input to a power conversion circuit, a determination unit that determines the correctness of the drive signal output from the determination unit, comprising: The determination unit determines the drive signal based on a drive command value to the power conversion circuit input from the outside and the drive permission signal to the power conversion circuit, The determination unit determines whether the drive signal matches a predetermined value, A failure detection circuit for a charging device.

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