Failure detection device of electric vehicle

Abstract

To provide a failure detection device of an electric vehicle which can appropriately detect a switching mechanism of switching output of a temperature sensor provided on a manual charge port and an automatic charge port.SOLUTION: A failure detection device of an electric vehicle includes a manual charge port, an automatic charge port, a switching mechanism, and a control part, wherein the manual charge port and the automatic charge port are provided on temperature sensors having different output characteristics, the switching mechanism outputs output of the temperature sensor on the currently used charge port, among the temperature sensors provided on the manual charge port and the automatic charge port, to the control part, and the control part determines presence / absence of the failure of the switching mechanism, on the basis of the change of the outputs of the temperature sensors at the time of switching by the switching mechanism.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a fault detection device for an electric vehicle. [Background technology]

[0002] Patent Document 1 discloses a technology in which a discharge resistor is connected to a battery via a relay, and if the rate at which the battery voltage drops from when the relay is turned off by turning the ignition off until the next time the ignition is turned on is greater than a predetermined value, it is determined that the relay is welded. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-032903 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, if an electric vehicle is equipped with a manual charging port, an automatic charging port, and a switching mechanism that switches the output of a temperature sensor provided in each of the port and the switching mechanism, a means for detecting a failure of the switching mechanism is required. However, the technology disclosed in Patent Document 1 cannot appropriately detect a failure of the switching mechanism of the electric vehicle as described above, and there is room for improvement.

[0005] The present disclosure has been made in consideration of the above, and aims to provide a fault detection device for an electric vehicle that can properly detect a fault in a switching mechanism that switches the output of a temperature sensor provided in a manual charging port and an automatic charging port. [Means for solving the problem]

[0006] The fault detection device for an electric vehicle according to the present disclosure comprises a manual charging port, an automatic charging port, a switching mechanism, and a control unit, wherein the manual charging port and the automatic charging port are each provided with temperature sensors having different output characteristics, the switching mechanism outputs the output of the temperature sensor of the charging port currently being used among the temperature sensors provided in the manual charging port and the automatic charging port, to the control unit, and the control unit determines whether or not there is a fault in the switching mechanism based on the change in output of the temperature sensor when switching is performed by the switching mechanism. Effect of the Invention

[0007] According to the present disclosure, it is possible to properly detect a failure in a switching mechanism that switches the output of a temperature sensor provided in a manual charging port and an automatic charging port. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a vehicle equipped with a failure detection device for an electric vehicle according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing details of a control unit, a manual charging port, an automatic charging port, and a switching mechanism of the failure detection device for an electric vehicle according to the embodiment. [Diagram 3] FIG. 3 is a graph for explaining the difference in output from the temperature sensors provided in the manual charging port and the automatic charging port of the fault detection device for an electrically powered vehicle according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing an example of the flow of a failure detection method executed by the failure detection device for an electric vehicle according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A fault detection device for an electric vehicle according to an embodiment of the present disclosure will be described with reference to the drawings. Note that components in the following embodiments include those that are easily replaceable by a person skilled in the art, or those that are substantially the same.

[0010] (Fault detection device) The configuration of a fault detection device for an electric vehicle according to an embodiment will be described with reference to Figures 1 to 3. The fault detection device for an electric vehicle according to an embodiment is for detecting a fault in a switching mechanism mounted on the electric vehicle.

[0011] The fault detection device for an electric vehicle according to the embodiment may be mounted on a vehicle such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), etc. The fault detection device for an electric vehicle according to the embodiment may be mounted on a vehicle such as a fuel cell electric vehicle (FCEV), a battery electric vehicle (BEV), etc.

[0012] 1(a), an electric vehicle 1 to which the fault detection device for an electric vehicle according to the embodiment is applied includes a control unit 11, a battery 12, a manual charging port 13, an automatic charging port 14, and a switching mechanism 15. Note that in this figure, only the configuration necessary to realize the fault detection device for an electric vehicle according to the embodiment is extracted from the configuration of the electric vehicle 1 and illustrated, and the other configuration is omitted.

[0013] The control unit 11 is an electronic control unit (ECU) whose main components are a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like.

[0014] The control unit 11 determines the presence or absence of a failure in the switching mechanism 15 based on a change in output of the temperature sensors 131, 132, 141, 142 when switching is performed by the switching mechanism 15 described below. The details of the failure determination of the switching mechanism 15 by the control unit 11 will be described later.

[0015] The battery 12 is, for example, a lithium ion secondary battery.

[0016] The manual charging port (manual charging inlet) 13 is a contact-type charging port for manual charging by a user (e.g., a driver) of the electric vehicle 1. This manual charging port 13 is provided, for example, at the front, rear, left side or right side of the body of the electric vehicle 1. Note that "manual charging" refers to, for example, a user directly connecting a charging connector installed in a charging station to the manual charging port 13 to charge the vehicle.

[0017] Furthermore, the manual charging port 13 is provided with temperature sensors 131, 132 having output characteristics different from those of the temperature sensors 141, 142 of the automatic charging port 14. These temperature sensors 131, 132 are for detecting poor contact and the like during manual charging. Furthermore, the temperature sensor 131 is, for example, a thermistor for the + terminal. Furthermore, the temperature sensor 132 is a thermistor for the - terminal. Note that "having different output characteristics" refers to a difference in the relationship of "temperature (°C) x resistance value (Ω)", for example, as shown in FIG. 3.

[0018] The automatic charging port (automatic charging inlet) 14 is a contact-type charging port that allows a user (e.g., a driver, etc.) of the electric vehicle 1 to automatically charge the vehicle. The automatic charging port 14 is provided, for example, on the bottom (under the floor) of the electric vehicle 1. Note that "automatic charging" refers to, for example, moving the electric vehicle 1 onto a road surface in which a ground unit is embedded, and flipping up a charging connector mounted on the ground unit toward the electric vehicle 1, thereby connecting the charging connector to the automatic charging port 14 and charging the vehicle.

[0019] Furthermore, the automatic charging port 14 is provided with temperature sensors 141, 142 whose output characteristics are different from those of the temperature sensors 131, 132 of the manual charging port 13. These temperature sensors 141, 142 are for detecting poor contact and the like during automatic charging. The temperature sensor 141 is, for example, a thermistor for the + terminal. Moreover, the temperature sensor 142 is a thermistor for the - terminal.

[0020] The switching mechanism 15 is for switching between the output of the temperature sensors 131, 132 provided in the manual charging port 13 and the output of the temperature sensors 141, 142 provided in the automatic charging port 14. This switching mechanism 15 outputs to the control unit 11 the output of the temperature sensor of the charging port currently being used among the temperature sensors 131, 132, 141, 142 provided in the manual charging port 13 and the automatic charging port 14.

[0021] 2, the switching mechanism 15 is configured with a relay circuit. The switching mechanism 15 is provided with resistors 151 and 152 for providing a difference in output characteristics between the temperature sensors 131 and 132 and the temperature sensors 141 and 142. In the figure, the resistor 151 is connected to the temperature sensor 141. The resistor 152 is connected to the temperature sensor 142.

[0022] In this way, by connecting resistors 151, 152 to temperature sensors 141, 142 on the automatic charging port 14 side, the temperature sensors 141, 142 have a higher voltage value relative to temperature than the temperature sensors 131, 132, as shown in FIG. 1(b), for example.

[0023] Here, when switching between the outputs of the temperature sensors 131, 132 and the outputs of the temperature sensors 141, 142 and outputting them to the control unit 11, it is possible to add an AD circuit or the like to the control unit 11, but this would require large-scale modification. Therefore, in this embodiment, the outputs of the temperature sensors 131, 132 and the outputs of the temperature sensors 141, 142 are switched using a switching mechanism 15 consisting of a simple relay circuit.

[0024] On the other hand, when such a switching mechanism 15 is provided, it is necessary to detect a failure (for example, a stuck relay) of the switching mechanism 15. In this embodiment, the difference in output characteristics of the temperature sensors 131, 132, 141, and 142 is utilized to easily detect a failure of the switching mechanism 15 without adding a special detection circuit or communication means.

[0025] That is, the control unit 11 compares the outputs of the temperature sensors 131, 132 and 141, 142 before and after switching by the switching mechanism 15. At that time, the control unit 11 calculates the temperature by referring to a conversion map or the like from the resistance values ​​output by the temperature sensors 131, 132, 141, 142 to temperatures.

[0026] If the difference between the outputs of temperature sensors 131, 132 and 141, 142 is equal to or greater than a predetermined specified value, control unit 11 determines that switching mechanism 15 is not malfunctioning and continues charging. On the other hand, if the difference between the outputs of both sensors is less than a predetermined specified value, control unit 11 determines that switching mechanism 15 is malfunctioning and stops charging. Note that this "specified value" can be determined based on the difference in output characteristics of temperature sensors 131, 132, 141, 142, for example.

[0027] (Fault detection method) The flow of a fault detection method executed by the fault detection device for an electric vehicle according to the embodiment will be described with reference to Fig. 4. In the following, a situation in which manual charging is switched to automatic charging is assumed, but fault detection is also possible using a similar method in a situation in which automatic charging is switched to manual charging.

[0028] First, when charging starts (step S1), the control unit 11 determines whether or not a charging connector is connected to the automatic charging port 14 (step S2). If it is determined in step S2 that a charging connector is connected to the automatic charging port 14 (Yes in step S2), the control unit 11 measures the outputs of the temperature sensors 131 and 132 before switching (step S3).

[0029] Next, when the outputs of the temperature sensors 131, 132 are switched to the outputs of the temperature sensors 141, 142 by the switching mechanism 15 (step S4), the control unit 11 measures the outputs of the temperature sensors 141, 142 after the switching (step S5). Next, the control unit 11 determines whether or not the output difference between the outputs of the temperature sensors 131, 132 before the switching and the outputs of the temperature sensors 141, 142 after the switching is equal to or greater than a predetermined specified value (step S6).

[0030] In step S6, if it is determined that the output difference between the temperature sensors 131, 132, 141, 142 before and after the switching is equal to or greater than a specified value (Yes in step S6), the control unit 11 determines that there is no failure in the switching mechanism 15, continues the charging sequence (step S7), and completes this process. On the other hand, if it is determined in step S6 that the output difference between the temperature sensors 131, 132, 141, 142 before and after the switching is less than a specified value (No in step S6), the control unit 11 determines that there is a failure in the switching mechanism 15 (step S8), and completes this process.

[0031] Here, in step S2, if it is determined that the charging connector is not connected to the automatic charging port 14 (No in step S2), the control unit 11 proceeds to the process of step S7 and subsequent steps.

[0032] According to the fault detection device for an electric vehicle in the embodiment described above, it is possible to properly detect a fault in the switching mechanism 15 that switches the output of the temperature sensors 131, 132, 141, 142 provided in the manual charging port 13 and the automatic charging port 14.

[0033] In addition, according to the fault detection device for an electric vehicle of the embodiment, a fault in the switching mechanism 15 can be detected simply by changing the output characteristics of the temperature sensors 131, 132, 141, 142, without adding any special circuits or communication means for fault detection.

[0034] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0035] 1 Electric vehicles 11 Control unit (ECU) 12 Battery 13 Manual charging port (manual charging inlet) 131 Temperature sensor (+ terminal thermistor) 132 Temperature sensor (- terminal thermistor) 14 Automatic charging port (automatic charging inlet) 141 Temperature sensor (+ terminal thermistor) 142 Temperature sensor (- terminal thermistor) 15 Switching mechanism 151,152 Resistance

Claims

[Claim 1] The charging device includes a manual charging port, an automatic charging port, a switching mechanism, and a control unit. The manual charging port and the automatic charging port are respectively provided with temperature sensors having different output characteristics, The switching mechanism outputs an output of a temperature sensor of a charging port currently being used, out of temperature sensors provided in the manual charging port and the automatic charging port, to the control unit; The control unit determines whether or not the switching mechanism has a failure based on a change in an output of the temperature sensor when the switching mechanism performs switching. Fault detection device for electric vehicles.

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