JP2018179835A - Detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection device that can detect fixation of a switch even when an electric path is grounded.SOLUTION: A control device 23 is configured to detect presence or absence of grounding by a first detection circuit 21 in a state where connectors 13a and 13b are turned on. When the grounding is detected in the state where the connectors 13a and 13b are turned on, the control device 23 is configured to determine fixation of the connectors 13a and 13b on the basis of a detection result of the first detection circuit 21 and a second detection circuit 22 in a state where the connectors 13a and 13b are turned off. Meanwhile, when the grounding is not detected in the state where the connectors 13a and 13b are turned on, the control device 23 is configured to determine fixation of the connectors 13a and 13b on the basis of whether a signal can be output from the first detection circuit 21 to the second detection circuit 22 in the state where the connectors 13a and 13b are turned off.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a detection device that detects sticking of a switch.

  Conventionally, there is known a technique for detecting welding (sticking) of a contactor (switch) by using an electric leakage detection device used to detect an electric leakage (ground fault) of a DC power supply, for example, in an electric car etc. For example, Patent Document 1). The leakage detection device described in Patent Document 1 includes a pseudo leakage circuit to generate a leakage state in a pseudo manner. Then, in a situation where an instruction to open the contactor is issued, the pseudo leakage circuit is configured to generate a leakage state in a pseudo manner, and the welding of the contactor is detected based on whether the leakage detection device detects the leakage state. It is done.

Patent No. 5541743 gazette

  By the way, in an automobile or the like, there are cases where it is possible to travel even if a short circuit occurs, so there is a demand to make the vehicle travel even in the short circuit condition.

  However, in the leakage detection device described in Patent Document 1, when there is an actual leakage, it is not possible to create a leakage state in a pseudo manner, so that welding of the contactor can not be detected. Generally, if the contactor is welded, the vehicle can not travel. Therefore, when the vehicle is desired to travel even in the short circuit condition, it is necessary to be able to detect the welding of the contactor even in the short circuit condition.

  The present invention has been made in view of the above circumstances, and has as its main object to provide a detection device capable of detecting the fixation of a switch even in a ground fault.

  In the first invention for solving the above problems, a detection device for detecting a ground fault of an electrical path between a DC power supply and an electrical load is provided closer to the electrical load than a switch provided in the electrical path. A first detection unit that detects a ground fault of the electric path, a second detection unit that is provided closer to the DC power supply than the switch and detects a ground fault of the electric path, the first detection unit, A ground fault determining unit that determines whether a ground fault has occurred in the electrical path based on a detection result of the second detector; and a ground fault detected by the ground fault determining unit; And a sticking determination unit that determines that the switch is sticking based on detection of a ground fault by the first detection unit and the second detection unit in a state where the release control is performed.

  The ground fault determination unit detects a ground fault using the first detection unit and the second detection unit. Then, when the ground detecting unit detects a ground fault, the adhesion determining unit detects that the first detecting unit and the second detecting unit detect the ground fault in a state in which the switch open control is performed. Based on this, it is determined that the switch is stuck and in the closed state. That is, even in the case where a ground fault has occurred, the fixation of the switch can be determined.

  In the second invention, the first detection unit and the second detection unit are configured to be able to input and output a signal to the electric path, and the fixation determination unit is configured to cause a ground fault by the ground fault judgment unit. Is not detected, the signal output from one of the first detection unit and the second detection unit is input by the other detection unit in a state in which the switch open control is executed. It is determined that the switch is stuck based on what has been done.

  Thereby, even if the ground fault does not occur, the fixation can be determined by using the first detection unit and the second detection unit.

  In the third invention, when the ground detection is performed by any one of the first detection unit and the second detection unit in a state where the closing control of the switch is performed, the ground determination unit is configured to perform a ground detection. If it is determined that a ground fault has occurred, and a ground fault is not detected by any one of the first detection unit and the second detection unit in a state where the closing control of the switch is executed, a ground fault is detected. It determines that it has not occurred.

  Thereby, in the state where the closing control of the switch is executed, the ground fault of the entire electric path can be detected by the detection result of any one of the first detection unit and the second detection unit.

  In the fourth invention, a plurality of the DC power supplies are connected in parallel to the electric load, the switch and the second detection unit are provided for each of the plurality of DC power supplies, and the determination unit (2) Using the detection results of each detection unit, determine whether or not the switch is fixed.

  When any of the plurality of switches is fixed, the second detection unit connected to the fixed switch detects a ground fault. Therefore, by providing the second detection unit for each of the plurality of switches and using the detection result for each of the second detection units, it becomes possible to identify which switch is adhering.

The circuit diagram of an abnormality detection apparatus. 7 is a flowchart of ground fault determination processing. 7 is a flowchart of fixation determination processing. (A) And (b) is a timing chart at the time of ground fault detection. (A)-(c) is a timing chart at the time of sticking determination. The timing chart at the time of a sticking detection. The circuit diagram of another example of an abnormality detection device. 7 is a flowchart of fixation determination processing.

  The embodiment will be described below. In the following embodiments, parts identical or equivalent to each other are denoted by the same reference numerals in the drawings, and the description of the parts having the same reference numerals is incorporated.

First Embodiment
An abnormality detection device 20 as a detection device shown in FIG. 1 is a device that determines a ground fault (leakage) of a high voltage battery (hereinafter referred to as a battery) mounted on a vehicle such as a hybrid vehicle or an electric vehicle. In the present embodiment, a circuit including the battery 11, the electric load 12, and the contactors 13a and 13b is referred to as a high voltage circuit 10.

  The battery 11 is a direct current power supply that supplies power to the electric load 12 of the vehicle, and is configured as, for example, a battery group in which a plurality of lithium ion batteries and the like are connected in series. The battery 11 and the electrical load 12 are connected via a pair of contactors 13a and 13b as switches. More specifically, the positive terminal of the battery 11 is connected to one end of the contactor 13a, and the negative terminal is connected to one end of the contactor 13b. That is, the contactor 13 a is provided on the high side (positive electrode side) of the battery 11, and the contactor 13 b is provided on the low side (negative electrode side) of the battery 11. Further, one end of the electrical load 12 is connected to the other end of the contactor 13a, and the other end of the electrical load 12 is connected to the other end of the contactor 13b.

  That is, the contactors 13a and 13b are connected to the negative electrode terminal and the positive electrode terminal of the battery 11, respectively, and the closing (on) and opening (off) of the contactors 13a and 13b are switched. And electrical connection (on) and disconnection (off) are switched. The contactors 13a and 13b are, for example, mechanical switches that operate the movable contact with respect to the fixed contact by the magnetic force of the electromagnetic coil and the elastic force of the spring. A semiconductor switch may be used instead of the contactors 13a and 13b.

  When the switch control device 50 performs closing control of the contactors 13a and 13b, the contactors 13a and 13b are in a closed state, and the battery 11 and the electrical load 12 are electrically connected. On the other hand, in the contactors 13a and 13b, when the switch control device 50 performs the open control, the contactors 13a and 13b are in the open state, and the battery 11 and the electric load 12 are electrically disconnected.

  For example, the switch control device 50 performs closing control of the contactors 13a and 13b when the ignition switch is turned on, and performs opening control of the contactors 13a and 13b when the ignition switch is turned off.

  The electric load 12 includes, for example, a VCU (Vehicle Control Unit) that performs various controls such as vehicle control and charge control, a PDU (Power Drive Unit) that drives and controls a traveling motor, and the like. When the contactors 13 a and 13 b are on, the power of the battery 11 is supplied to the electrical load 12. The electrical load 12 is not limited to these and may be arbitrarily changed.

  The battery 11 and the electrical load 12 are respectively insulated from the vehicle body 100 of the vehicle, but between the battery 11 and the vehicle body 100, there is a ground insulation resistor 30 consisting of an insulation resistance Rg0 and a stray capacitance Cg0. Similarly, between the electrical load 12 and the vehicle body 100, there is a ground insulation resistance 31 consisting of an insulation resistance Rg1 and a stray capacitance Cg1. In FIG. 1, the state where the insulation resistance Rg0 is connected to the battery 11 and the vehicle body 100 and the stray capacitance Cg0 is connected in parallel to the insulation resistance Rg0 is shown for convenience of explanation. Further, FIG. 1 shows a state in which the insulation resistance Rg1 is connected to the electric load 12 and the vehicle body 100, and the stray capacitance Cg1 is connected in parallel to the insulation resistance Rg1 for convenience of explanation.

  In the normal state where no ground fault occurs on the battery 11 side, the insulation resistance Rg0 of the ground insulation resistance 30 is maintained at a predetermined value or more (for example, several MΩ or more). On the other hand, at the time of the abnormality which the ground fault has generate | occur | produced on the battery 11 side, insulation resistance Rg0 of the ground insulation resistance 30 falls. More specifically, at the time of an abnormality in which a ground fault occurs in the electrical path on the side of the battery 11 relative to the contactor 13a, the insulation resistance Rg0 of the ground insulation resistance 30 is lowered. The same is true even if a ground fault occurs between the contactor 13 b and the battery 11.

  Further, in the normal state in which no ground fault occurs on the electrical load 12 side, the insulation resistance Rg1 of the ground insulation resistance 31 is maintained at a predetermined value or more (for example, several MΩ or more). On the other hand, at the time of the abnormality which the ground fault has generate | occur | produced on the electric load 12 side, insulation resistance Rg1 of the ground insulation resistance 31 falls. More specifically, at the time of an abnormality in which a ground fault occurs in the electrical path on the side of the electrical load 12 with respect to the contactor 13a, the insulation resistance Rg1 of the ground insulation resistance 31 decreases. The same is true even if a ground fault occurs between the contactor 13 b and the electrical load 12.

  Next, the abnormality detection device 20 will be described. The abnormality detection device 20 detects a ground fault of the electrical path between the battery 11 and the electrical load 12. The abnormality detection device 20 includes a first detection circuit 21 as a first detection unit, a second detection circuit 22 as a second detection unit, and a control device 23. The first detection circuit 21 and the second detection circuit 22 are respectively provided on one end side and the other end side of the contactor 13 b on the negative electrode side of the battery 11.

  The first detection circuit 21 is a circuit provided (connected) on the side of the electrical load 12 with respect to the contactors 13a and 13b, and can detect a ground fault of the electrical path on the side of the electrical load 12 with respect to the contactors 13a and 13b. Is configured. Specifically, the first detection circuit 21 includes a first oscillation circuit 211, a first resistor 212, a first coupling capacitor 213, and a first filter 214.

  The second detection circuit 22 is a circuit provided (connected) to the battery 11 side than the contactors 13a and 13b, and configured to be able to detect a ground fault of the electric path on the battery 11 side than the contactors 13a and 13b. It is done. Specifically, the second detection circuit 22 includes a second oscillation circuit 221, a second resistor 222, a second coupling capacitor 223, and a second filter 224.

  The oscillation circuits 211 and 221 are circuits that output an alternating current signal (pulse signal) of a predetermined oscillation frequency. The duty ratio of the AC signal and the transmission frequency can be changed.

  The resistors 212 and 222 are provided to divide an AC signal in relation to the ground insulation resistors 30 and 31, respectively. One ends of the resistors 212 and 222 are connected to the oscillating circuits 211 and 221, and the other ends are connected to connection points N1 and N2 of the coupling capacitors 213 and 223 and the filters 214 and 224, respectively.

  The coupling capacitors 213 and 223 are elements for blocking a DC component and passing an AC signal between the abnormality detection device 20 and the battery 11 or the electric load 12. One end of the first coupling capacitor 213 is connected to the first resistor 212, and the other end is connected to the electrical load 12 side more than the contactors 13a and 13b. In the present embodiment, the other end of the first coupling capacitor 213 is connected between the contactor 13 b and the electrical load 12. One end of the second coupling capacitor 223 is connected to the second resistor 222, and the other end is connected to the battery 11 side more than the contactors 13a and 13b. In the present embodiment, the other end of the second coupling capacitor 223 is connected between the contactor 13 b and the battery 11. The first coupling capacitor 213 has a larger capacity than the second coupling capacitor 223.

  The filters 214 and 224 are analog filters (low pass filters) including resistors and capacitors. The filters 214 and 224 are provided, for example, as anti-aliasing filters that suppress the occurrence of aliasing when performing A / D conversion described later. The filters 214 and 224 may be band pass filters as well as low pass filters.

  The control device 23 is configured to include a RAM, a ROM, a flash memory, and the like in addition to the CPU, and is connected to the first detection circuit 21 and the second detection circuit 22. More specifically, the control device 23 is connected to the oscillation circuits 211 and 221, and is configured to be able to cause the oscillation circuits 211 and 221 to output alternating current signals. Further, the control device 23 is connected to the filters 214 and 224, respectively, and is configured to be able to input an AC signal through the filters 214 and 224, respectively.

  Then, the control device 23 performs various processes by the CPU executing various programs stored in the ROM. For example, the control device 23 A / D converts the alternating current signal input through the filters 214 and 224, and executes ground fault determination processing based on the alternating current signal. Therefore, the control device 23 has a function as a ground fault determination unit.

  The ground fault determination process will be described in detail with reference to FIG. The ground fault determination process is performed by the control device 23 at predetermined intervals. When the ground fault determination process is started, the control device 23 first performs the process of step S11.

  In step S11, the control device 23 determines whether the ignition switch is turned on and the contactors 13a and 13b are turned on. Specifically, the control device 23 determines whether the closing control of the contactors 13a and 13b is being performed by the switch control device 50. When the switch control device 50 performs the closing control, the control device 23 of the abnormality detection device 20 is configured to be able to input that effect. Similarly, when the opening control is performed by the switch control device 50, the control device 23 is configured to be able to input that effect.

  If the determination result in step S11 is negative (NO) (if the contactors 13a and 13b are not turned on), the control device 23 ends the ground fault determination process. If the determination result in step S11 is affirmative (YES) (if the contactors 13a and 13b are on), the control device 23 proceeds to step S12.

  In step S12, the control device 23 determines whether or not it is a predetermined ground fault detection period. The ground fault detection period is set by, for example, the control device 23 at predetermined intervals (for example, one minute). The length from the start to the end of the ground fault detection period is, for example, 5000 msec. The setting interval of the ground fault detection period and the length of the ground fault detection period may be arbitrarily changed.

  If the determination result of step S12 is negative (NO) (if not the ground fault detection period), the control device 23 ends the ground fault determination process. When the determination result of step S12 is affirmation (YES) (when it is a ground fault detection period), the control apparatus 23 transfers to step S13.

  In step S13, the control device 23 causes the first detection circuit 21 (more specifically, the first oscillation circuit 211) to output an AC signal during the ground fault detection period. Thereby, the first oscillation circuit 211 outputs an AC signal to the control device 23 through the first filter 214, and the electrical path between the battery 11 and the electrical load 12 through the first coupling capacitor 213. Output an AC signal. Further, the control device 23 A / D converts the alternating current signal input from the first detection circuit 21 (more specifically, the first filter 214) during the ground fault detection period, and converts the alternating current signal after conversion into the abnormality detection device 20. Store in the storage unit. Thereafter, the process proceeds to step S14.

  In step S14, the control device 23 calculates the crest value (amplitude) of the AC signal (AC signal after conversion) input through the first detection circuit 21, and the crest value and a predetermined ground fault judgment value. The presence or absence of a ground fault is determined by the comparison of

  That is, when the crest value of the AC signal input through the first detection circuit 21 is equal to or greater than the ground fault determination value, the controller 23 indicates that the voltage division of the first resistance 212 with respect to the ground insulation resistance 30 and the ground insulation resistance 31. If the ratio is low, it is determined that there is no ground fault. On the other hand, when the peak value of the AC signal inputted through the first detection circuit 21 becomes lower than the ground fault judgment value, that is, with the decrease of the ground insulation resistance 30 or the ground insulation resistance 31, the ground insulation resistances 30 and 31. When the partial pressure ratio of the first resistor 212 with respect to H.sub.2 is high, it is determined that a ground fault has occurred.

  It should be noted that, even if there is a ground fault on either the battery 11 side or the electric load 12 side of the contactors 13a and 13b, the contactors 13a and 13b are in the closed state, so in either case, the ground fault Affected by That is, regardless of which of the contactors 13a and 13b the side of the battery 11 and the side of the electrical load 12 cause a ground fault, the control device 23 determines the ground based on the AC signal input through the first detection circuit 21. A fault can be detected. In addition, the control device 23 can detect a ground fault in the electric path on the contactor 13a side in the same manner as a ground fault in the electric path on the contactor 13b side.

  When the determination result of step S14 is affirmative (YES) (when it is determined that a ground fault has occurred), the control device 23 proceeds to step S15. When the determination result of step S14 is negative (NO) (when it is determined that there is no ground fault), the control device 23 proceeds to step S16.

  In step S15, the control device 23 stores the presence of a ground fault in the storage unit of the abnormality detection device 20, and ends the ground fault determination process. When the control device 23 determines that a ground fault has occurred in the ground fault determination process, the control device 23 executes various processes according to the occurrence of the ground fault. For example, the control device 23 outputs a notification signal notifying that a ground fault has occurred.

  In step S16, the control device 23 stores no ground fault in the storage unit of the abnormality detection device 20, and ends the ground fault determination process. As described above, when the ground detection is detected by the first detection circuit 21 in the state where the closing control of the contactors 13a and 13b is performed by executing the ground fault determination process, the control device 23 performs the ground fault. It determines that it has occurred. On the other hand, when the first detection circuit 21 does not detect a ground fault in the state where the closing control of the contactors 13a and 13b is executed, the control device 23 determines that the ground fault does not occur.

  By the way, in a vehicle, even if a ground fault occurs, it may be possible to travel, and there is a demand to distinguish it from the adherence of the contactors 13a and 13b that makes continuous travel basically impossible. The adhesion of the contactors 13a and 13b means, for example, a state in which the movable contact is welded to the fixed contact under the influence of heat or the like, and the closed state is not brought into the open state. In addition to the above, the fixation includes a state in which the closed state does not become the open state (closed failure) due to some abnormality. Hereinafter, the adhesion of the contactors 13a and 13b may be simply referred to as adhesion.

  Therefore, the following sticking determination process is performed so that the sticking can be determined even in the ground state. The sticking determination process is performed by the control device 23 at predetermined intervals. As shown in FIG. 3, when the sticking determination process is started, the control device 23 first performs the process of step S21.

  In step S21, the control device 23 determines whether the ignition switch is turned off and the contactors 13a and 13b are turned off. Specifically, the control device 23 determines whether the switch control device 50 performs open control of the contactors 13a and 13b. That is, the release control may be performed, and it does not matter whether the contactors 13a and 13b are actually in the open state. That is, even if the contactors 13a and 13b are stuck and not open, if the release control is performed, the control device 23 determines that the contactors 13a and 13b are turned off. Hereinafter, in the sticking determination process, the state in which the contactors 13a and 13b are turned off refers to the state in which the opening control is performed, and it does not matter whether the state is the opening state in practice.

  If the determination result in step S21 is negative (NO) (if the contactors 13a and 13b are not turned off), the control device 23 ends the sticking determination process. If the determination result in step S21 is affirmative (YES) (if the contactors 13a and 13b are off), the control device 23 proceeds to step S22.

  In step S22, control device 23 determines whether or not a ground fault has been detected with contactors 13a and 13b turned on. Specifically, control device 23 determines whether or not a ground fault is stored in the ground fault determination process that is executed when the ignition switch is turned on.

  When the determination result of step S22 is affirmative (YES) (when a ground fault is detected), the control device 23 proceeds to step S23. When the determination result of step S22 is negative (NO) (when a ground fault is not detected), the control device 23 proceeds to step S29.

  In step S23, with the contactors 13a and 13b turned off, the control device 23 causes the first oscillation circuit 211 and the second oscillation circuit 221 to output alternating current signals during the sticking determination period. As a result, the first oscillation circuit 211 outputs an AC signal to the control device 23 through the first filter 214, and the electrical path between the contactor 13 b and the electrical load 12 through the first coupling capacitor 213. Output an AC signal. Similarly, the second oscillation circuit 221 outputs an alternating current signal to the control device 23 through the second filter 224, and an electric path between the battery 11 and the contactor 13b through the second coupling capacitor 223. It will output an alternating current signal.

  The sticking determination period is set by the control device 23 for a predetermined period, for example, 250 mses after the contactors 13a and 13b are turned off. Further, the control device 23 outputs an alternating current signal of a duty ratio and a transmission frequency different from the ground fault detection period during the fixation determination period. Specifically, during the fixation determination period, the duty ratio of the AC signal is reduced and the transmission frequency is increased, as compared with the ground fault detection period. Thereby, the sticking determination period can be shortened.

  Further, during the sticking determination period, the control device 23 A / D converts the alternating current signal input from the first detection circuit 21 (more specifically, the first filter 214), and stores the converted alternating current signal in the storage unit. Similarly, the control device 23 A / D converts the alternating current signal input from the second detection circuit 22 (more specifically, the second filter 224) during the sticking determination period, and stores the converted alternating current signal in the storage unit. . After the fixation determination period ends, the process proceeds to step S24.

  In step S24, the control device 23 calculates the peak value (amplitude) of the AC signal (AC signal after conversion) input from the first detection circuit 21, and determines whether the peak value becomes equal to or higher than the ground fault determination value. To determine the

  In step S24, when the crest value of the alternating current signal input from the first detection circuit 21 is equal to or greater than the ground fault determination value, the control device 23 does not ground to the electrical load 12 side than the contactors 13a and 13b. judge. That is, when the voltage dividing ratio of the first resistor 212 to the ground insulating resistor 31 is low, it is determined that the electrical load 12 does not have a ground fault. Also, at the same time, the control device 23 determines that it is not stuck.

  That is, when the contactors 13a and 13b are in the closed state (in the ground fault determination process) and a ground fault is detected, the contactor 13a or 13b is grounded on either the electric load 12 side or the battery 11 side. Can be recognized. For this reason, in the state where the contactors 13a and 13b are turned off, when the ground fault is not detected on the side of the electric load 12, it can be recognized that the contactors 13a and 13b are not closed due to the sticking.

  In other words, it is recognized that ground fault has occurred on the battery 11 side, and that the contactors 13a and 13b are normally opened based on the release control, and are not affected by the ground fault occurring on the battery 11 side. it can. The reason is that if the contactors 13a and 13b are not normally opened due to the sticking and are in the closed state, the ground fault on the battery 11 side is detected (the ground fault on the battery 11 side is detected And the peak value should be lower than the ground fault judgment value.

  When the determination result of step S24 is affirmative (YES) (when the peak value is equal to or greater than the ground fault determination value), the control device 23 proceeds to step S25. That is, when the ground fault is not detected on the side of the electric load 12, the control device 23 proceeds to step S25. If the determination result in step S24 is affirmative, if the control device 23 is an electrical path closer to the electrical load 12 than the contactors 13a and 13b, a ground fault occurs on either the contactor 13a side or the contactor 13b side. It can be determined that it has not occurred.

  On the other hand, when the determination result of step S24 is negative (NO) (when the peak value is lower than the ground fault determination value), the control device 23 proceeds to step S26. That is, when not detecting that a ground fault is detected on the side of the electric load 12, the control device 23 proceeds to step S26.

  In step S25, the control device 23 stores in the storage unit that the contactors 13a and 13b are not fixed. The control device 23 also stores that there is no ground fault on the side of the electric load 12 than the contactors 13a and 13b, that is, it is a ground fault on the battery 11 side. Then, the control device 23 ends the sticking determination process.

  In step S26, the control device 23 calculates the crest value (amplitude) of the AC signal (AC signal after conversion) input from the second detection circuit 22, and determines whether the crest value is equal to or more than the ground fault judgment value. To determine the

  In step S26, when the peak value of the AC signal input from the second detection circuit 22 is equal to or greater than the ground fault determination value, the control device 23 determines that the battery 11 does not have a ground fault than the contactors 13a and 13b. Do. That is, when the voltage dividing ratio of the second resistor 222 to the ground insulating resistor 30 is low, it is determined that the battery 11 does not cause a ground fault. At the same time, the control device 23 determines that the contactors 13a and 13b are not stuck.

  That is, when the contactors 13a and 13b are in the closed state (in the ground fault determination process) and a ground fault is detected, the contactor 13a or 13b is grounded on either the electric load 12 side or the battery 11 side. Can be recognized. For this reason, in the state where the contactors 13a and 13b are turned off, when the ground fault is not detected on the battery 11 side, it can be recognized that the contactors 13a and 13b are not closed due to the sticking.

  That is, ground fault occurs on the side of the electrical load 12, and the contactors 13a and 13b are normally opened based on the release control, and are not affected by the ground fault occurring on the electrical load 12 side. It can be recognized. This is because, if the contactors 13a and 13b are not normally opened due to the adherence and are in the closed state, the effect of the ground fault on the side of the electrical load 12 (a ground fault on the side of the electrical load 12 Is detected, and the peak value should be lower than the ground fault judgment value.

  If the determination result in step S26 is affirmative (YES) (if the peak value is equal to or greater than the ground fault determination value), control device 23 proceeds to step S27. That is, when the ground fault is not detected on the battery 11 side, the control device 23 proceeds to step S27. If the determination result in step S26 is affirmative, the control device 23 generates a ground fault on either the contactor 13a side or the contactor 13b side if the electric path is closer to the battery 11 than the contactors 13a and 13b. It can be determined that it is not.

  On the other hand, when the determination result of step S26 is negative (NO) (when the peak value is lower than the ground fault determination value), the control device 23 proceeds to step S28. That is, when not detecting that a ground fault has been detected on the battery 11 side, the control device 23 proceeds to step S28.

  In step S27, the control device 23 stores in the storage unit that the contactors 13a and 13b are not fixed. The control device 23 also stores that there is no ground fault on the side of the battery 11 with respect to the contactors 13a and 13b, that is, a ground fault on the side of the electric load 12. Then, the control device 23 ends the sticking determination process.

  In step S28, the control device 23 stores in the storage unit that the contactors 13a and 13b are stuck, and ends the sticking determination process. That is, in the state where the contactors 13a and 13b are turned off, the control device 23 determines that the fixing is performed based on the detection of the ground fault by the first detection circuit 21 and the second detection circuit 22.

  That is, when any peak value of the AC signal input through the filters 214 and 224 is lowered, the control device 23 determines that the signals are fixed. Because, if it is normally open, a ground fault should be detected on either the battery 11 side or the electric load 12 side and no ground fault should be detected on the other side. is there. That is, if the open state is normal, the wave height value of one of the AC signals should be lower than the ground fault judgment value, and the wave height value of the other AC signal should be higher than the ground fault judgment value. It is.

  In addition, when it determines with adhering in the sticking determination process, the control apparatus 23 performs various processes according to generation | occurrence | production of sticking. For example, the control device 23 outputs a notification signal for notifying the occurrence of sticking.

  As shown in the above steps S23 to S28, when a ground fault is detected, the control device 23 performs a ground fault on each of the first detection circuit 21 and the second detection circuit 22 in a state where the contactors 13a and 13b are turned off. Functions as a sticking judgment unit which judges that the stick is fixed based on the detection of.

  In step S29, the control device 23 causes the first detection circuit 21 (more specifically, the first oscillation circuit 211) to output an alternating current signal while the contactors 13a and 13b are off during the sticking determination period. Thereby, the first oscillation circuit 211 outputs an AC signal to the control device 23 through the first filter 214, and the electrical path between the battery 11 and the electrical load 12 through the first coupling capacitor 213. Output an AC signal. During this sticking determination period, the AC signal is not output from the second detection circuit 22 (more specifically, the second oscillation circuit 221).

  Further, during the sticking determination period, the control device 23 A / D converts the alternating current signal input through the second detection circuit 22 and stores the converted alternating current signal in the storage unit. Then, after the fixation determination period ends, the process proceeds to step S30.

  In step S30, the control device 23 calculates the crest value (amplitude) of the AC signal (AC signal after conversion) input through the second detection circuit 22, and the crest value is equal to or higher than a predetermined sticking determination value. Determine if there is.

  If the contactors 13a and 13b are stuck (that is, if they remain in the closed state), the AC signal output by the first detection circuit 21 is the second detection circuit 22 (more specifically, the second filter 224). Will be input via Therefore, in step S30, when the crest value is equal to or more than the predetermined sticking determination value (step S30: YES), the control device 23 performs an AC signal through the second detection circuit 22 based on the sticking of the contactors 13a and 13b. Is determined, and the process proceeds to step S31.

  If the contactors 13a and 13b are not fixed (that is, if the contactors 13 are normally open), the alternating current signal output by the first detection circuit 21 may not be input through the second detection circuit 22. Absent. That is, in step S30, when the crest value is lower than the predetermined sticking determination value (step S30: NO), the control device 23 does not receive an AC signal through the second detection circuit 22, and the contactors 13a and 13b It determines that it has not stuck and complete | finishes a sticking determination process.

  In step S31, the control device 23 stores the fact that the contactors 13a and 13b are stuck in the storage unit, and ends the sticking determination process. In addition, when it determines with adhering in the sticking determination process, the control apparatus 23 performs various processes according to generation | occurrence | production of sticking. For example, the control device 23 outputs a notification signal for notifying the occurrence of sticking.

  Next, based on FIG. 4, when detecting a ground fault, the appearance of input and output of an alternating current signal will be described. When the contactors 13a and 13b are in the on state, the ground fault detection period T11 is set at predetermined intervals. Further, in the ground fault detection period T11, an alternating current signal is output from the first oscillation circuit 211.

  When there is no ground fault, as shown in FIG. 4A, the crest value of the AC signal input through the first filter 214 in the ground fault detection period T11 becomes a value greater than or equal to the ground fault determination value X1. On the other hand, when there is a ground fault, as shown in FIG. 4B, in the ground fault detection period T11, the crest value of the AC signal input through the first filter 214 is lower than the ground fault judgment value X1. It becomes a value.

  Next, based on FIG. 5, when determining sticking, the mode of the input-output of an alternating current signal is demonstrated. First, the case where a ground fault is detected will be described. When the contactors 13a and 13b are in the off state, the sticking determination period T12 is set. Further, in the sticking determination period T12, AC signals are output from the oscillation circuits 211 and 221, respectively.

  In the case of sticking, as shown in FIG. 5A, the crest values of the AC signals input through the filters 214 and 224 in the sticking determination period T12 are both lower than the predetermined ground fault judgment value X1. Become. That is, both of the detection circuits 21 and 22 detect the ground fault.

  In the case where the electrical load 12 does not stick to the ground, as shown in FIG. 5B, the wave of the AC signal input through the first filter 214 in the sticking determination period T12. The high value is lower than the ground fault judgment value X1. On the other hand, the crest value of the AC signal input through the second filter 224 in the fixation determination period T12 is a value equal to or greater than the ground fault determination value X1. That is, the first detection circuit 21 detects a ground fault, and the second detection circuit 22 does not detect the ground fault.

  In the case where the battery 11 does not stick to the ground, as shown in FIG. 5C, the peak value of the AC signal input through the first filter 214 in the sticking determination period T12. Is a value equal to or greater than the ground fault determination value X1. On the other hand, the crest value of the AC signal input through the second filter 224 in the fixation determination period T12 is a value lower than the ground fault determination value X1. That is, the first detection circuit 21 does not detect the ground fault, and the second detection circuit 22 detects the ground fault.

  Next, with reference to FIG. 6, a state of input and output of an alternating current signal when determining sticking when no ground fault is detected will be described. When the contactors 13a and 13b are in the off state, the sticking determination period T13 is set. In addition, an alternating current signal is output from the first oscillation circuit 211 in the fixation determination period T13. On the other hand, an alternating current signal is not output from the second oscillation circuit 221.

  In the case of sticking, as shown in FIG. 6A, the crest value of the AC signal input through the second filter 224 in the sticking determination period T13 becomes a value greater than or equal to the sticking determination value X2. That is, the AC signal output from the first detection circuit 21 is input to the second detection circuit 22 through the fixed contactors 13a and 13b.

  If not sticking, as shown in FIG. 6B, the crest value of the AC signal input through the second filter 224 in the sticking determination period T13 becomes a value lower than the sticking determination value X2. That is, even if an alternating current signal is output from the first detection circuit 21, the contactors 13 a and 13 b are in the open state, and therefore, are not input to the second detection circuit 22.

  According to the above, the following excellent effects can be achieved.

  The control device 23 determines the presence or absence of a ground fault by the first detection circuit 21 in the ground fault determination process. When the ground fault is determined, the control device 23 causes the first detection circuit 21 and the second detection circuit 22 to detect the ground fault while the contactors 13a and 13b are turned off. Determine what you are doing. That is, even in the case where a ground fault occurs, the sticking of the contactors 13a and 13b can be determined.

  When a ground fault is detected, the sticking is determined by specifying which of the side of the battery 11 or the side of the electric load 12 is in the ground fault on the premise of the occurrence of the ground fault. That is, when there is no ground fault, it is not possible to determine the presence or absence of sticking based on the detection results of the first detection circuit 21 and the second detection circuit 22. Therefore, the controller 23 determines that the alternating current signal output from the first detection circuit 21 in the state where the contactors 13a and 13b are turned off is stuck based on whether or not the second detection circuit 22 inputs. I decided to make a decision. Thereby, even if no ground fault occurs, sticking can be determined by diverting (utilizing) the first detection circuit 21 and the second detection circuit 22.

  The control device 23 is configured to detect a ground fault in the high voltage circuit 10 by dividing the AC signal output from the oscillation circuits 211 and 221. That is, in order to detect a ground fault, the first detection circuit 21 and the second detection circuit 22 are configured to be able to input and output alternating current signals to the electrical path between the battery 11 and the electrical load 12. Therefore, when performing the sticking determination, the input / output function of the signal included in the first detection circuit 21 and the second detection circuit 22 is diverted. As a result, the first detection circuit 21 and the second detection circuit 22 do not need to have new input / output functions.

  In comparison with the second coupling capacitor 223, the capacitance of the first coupling capacitor 213 is increased. As the capacity of the capacitor increases, AC signals can be easily transmitted. Thus, when the contactors 13a and 13b are fixed, the alternating current signal output from the first oscillation circuit 211 can be easily transmitted to the second detection circuit 22. That is, the determination accuracy of sticking can be improved.

  When the contactors 13a and 13b are in the closed state, that is, when the current flows from the battery 11 to the electrical load 12, the noise is likely to be large. Therefore, during the ground fault detection period, the duty ratio of the AC signal is increased as compared to the fixation determination period to suppress the influence of noise. On the other hand, during the fixation determination period in which the contactors 13a and 13b are turned off, the duty ratio of the AC signal is reduced as compared to the ground fault detection period, and the increase in the fixation determination period is suppressed.

Second Embodiment
In the second embodiment, the configurations of the high voltage circuit 10 and the abnormality detection device 20 are changed. As shown in FIG. 7, in the high voltage circuit 10, a plurality of (three in the present embodiment) batteries 11 a to 11 c are connected in parallel to the electric load 12. Further, the contactors 61a and 61b are connected to the battery 11a, the contactors 62a and 62b are connected to the battery 11b, and the contactors 63a and 63b are connected to the battery 11c. The respective contactors 61a to 63a and 61b to 63b are turned on and off, respectively, so that the batteries 11a to 11c are turned on and off with respect to the electric load 12.

  In the abnormality detection device 20, second detection circuits 22a to 22c are provided for each of the batteries 11a to 11c. That is, the second detection circuit 22a is provided (connected) closer to the battery 11a than the contactors 61a and 61b. A second detection circuit 22b is provided (connected) closer to the battery 11b than the contactors 62a and 62b. A second detection circuit 22c is provided (connected) closer to the battery 11c than the contactors 63a and 63b.

  In the sticking determination process of the second embodiment, whether the control device 23 is sticking to each of the contactors 61a to 63a and 61b to 63b to be a pair, using the detection result of each of the second detection circuits 22a to 22c. Determine Hereinafter, it demonstrates in detail based on FIG.

  In step S121, the control device 23 determines whether the contactors 61a to 63a and 61b to 63b are turned off.

  If the determination result of step S121 is negative (NO), the control device 23 ends the sticking determination process. If the determination result of step S121 is affirmative (YES), the control device 23 proceeds to step S122.

  In step S122, control device 23 determines whether or not a ground fault has been detected with contactors 61a to 63a and 61b to 63b turned on. That is, in the ground fault determination process, it is determined whether a ground fault has been detected.

  If the determination result of step S122 is affirmative (YES), the control device 23 proceeds to step S123. If the determination result of step S122 is negative (NO), the control device 23 proceeds to step S129.

  In step S123, with the contactors 61a to 63a and 61b to 63b turned off, the control device 23 causes the first detection circuit 21 and the second detection circuits 22a to 22c to output alternating current signals, respectively, during the sticking determination period. .

  Further, the control device 23 A / D converts the alternating current signal input from the first detection circuit 21 during the sticking determination period, and stores the converted alternating current signal in the storage unit. Similarly, the control device 23 A / D converts the alternating current signals respectively input from the second detection circuits 22a to 22c during the sticking determination period, and stores the converted alternating current signals in the storage unit. After the fixation determination period ends, the process proceeds to step S124.

  In step S124, the control device 23 calculates the peak value of the AC signal (AC signal after conversion) input from the first detection circuit 21, and determines whether the peak value is equal to or greater than a predetermined ground fault determination value. Determine

  If the determination result of step S124 is affirmative (YES), the control device 23 determines that there is no ground fault on the electrical load 12 side, and proceeds to step S125. On the other hand, when the determination result of step S124 is negative (NO), the control device 23 proceeds to step S126.

  In step S124, when the peak value is equal to or greater than the ground fault determination value, the control device 23 can determine that the ground is not broken on the side of the electric load 12. Also, at the same time, the control device 23 can determine that it is not stuck.

  In step S125, the control device 23 stores in the storage unit that the contactors 61a to 63a and 61b to 63b are not fixed. In addition, the control device 23 stores that there is no ground fault on the side of the electric load 12, that is, a ground fault on the side of the batteries 11a to 11c.

  Also, in step S125, the control device 23 specifies the second detection circuits 22a to 22c to which the AC signal having a wave height value lower than the ground fault judgment value is input, thereby causing a ground fault on any of the batteries 11a to 11c. It may be determined if it is. Then, the control device 23 ends the sticking determination process.

  In step S126, the control device 23 calculates the peak values of the AC signals (AC signals after conversion) input from the second detection circuits 22a to 22c, and determines whether all the peak values are equal to or greater than the ground judgment value It is determined whether or not.

  If the determination result of step S126 is affirmative (YES) (if all the peak values are equal to or greater than the ground judgment value), the control device 23 proceeds to step S127. On the other hand, when the determination result in step S126 is negative (NO) (when all the peak values are not equal to or larger than the ground fault determination value), the control device 23 proceeds to step S128.

  In step S126, when all the crest values are equal to or greater than the ground fault determination value, the control device 23 can determine that there is no ground fault on all the batteries 11a to 11c. At the same time, the control device 23 can determine that the contactors 61a to 63a and 61b to 63b are not fixed.

  In step S127, the control device 23 stores in the storage unit that the contactors 61a to 63a and 61b to 63b are not fixed. In addition, the control device 23 stores that grounding is not performed on the side of the batteries 11a to 11c with respect to the contactors 61a to 63a and 61b to 63b, that is, grounding on the side of the electrical load 12 is stored. Then, the control device 23 ends the sticking determination process.

  In step S128, the control device 23 stores in the storage unit that any one of the contactors 61a to 63a and 61b to 63b is fixed, and ends the fixation determination process. That is, the control device 23 adheres based on the detection of the ground fault by the first detection circuit 21 and the second detection circuits 22a to 22c in a state where the contactors 61a to 63a and 61b to 63b are turned off. It is determined that

  At that time, the control device 23 determines whether or not the contactors 61a to 63a and 61b to 63b to be paired are fixed by using the detection results of the second detection circuits 22a to 22c. That is, the control device 23 specifies the second detection circuits 22a to 22c that output the alternating current signal having a lower peak value than the ground fault determination value among the alternating current signals input from the second detection circuits 22a to 22c. Then, the control device 23 determines that the contactors 61a to 63a and 61b to 63b connected to the specified second detection circuits 22a to 22c are fixed, and stores the results.

  In step S129, the control device 23 causes the first detection circuit 21 to output an alternating current signal while the contactors 61a to 63a and 61b to 63b are off during the sticking determination period. Note that the alternating current signal is not output by the second detection circuits 22a to 22c during the fixation determination period.

  Further, during the sticking determination period, the control device 23 A / D converts the alternating current signals respectively input from the second detection circuits 22a to 22c, and stores the converted alternating current signals in the storage unit. Then, after the fixation determination period ends, the process proceeds to step S130.

  In step S130, the control device 23 calculates the peak value of the AC signal (AC signal after conversion) input from the second detection circuits 22a to 22c, and determines whether any of the peak values is equal to or higher than the fixation determination value. Determine if

  If any of the wave height values is equal to or higher than the fixation determination value (step S130: YES), that is, if any of the second detection circuits 22a to 22c receives an alternating current signal, the control device 23 selects one of the contactors 61a. It is determined that ~ 63a and 61b-63b are adhered, and the process proceeds to step S131.

  On the other hand, when all the crest values are lower than the predetermined sticking determination value (step S130: NO), the control device 23 determines that the sticking is not performed, and terminates the sticking determination process. That is, when all the second detection circuits 22a to 22c do not receive an alternating current signal, the control device 23 determines that they are not stuck.

  In step S131, the control device 23 stores in the storage unit that the contactors 61a to 63a and 61b to 63b are fixed. At that time, the control device 23 specifies the second detection circuits 22a to 22c which have input an alternating current signal whose peak value is equal to or higher than the fixation determination value. Then, the control device 23 determines that the contactors 61a to 63a and 61b to 63b connected to the specified second detection circuits 22a to 22c are fixed, and stores that effect. Then, the sticking determination process is ended.

  According to the above, the following excellent effects can be achieved.

  When any one of the paired contactors 61a to 63a and 61b to 63b is fixed, the second detection circuits 22a to 22c connected to the fixed contactors 61a to 63a and 61b to 63b are connected to ground. Will be detected. Therefore, the second detection circuits 22a to 22c are provided for each pair of contactors 61a to 63a and 61b to 63b, and the detection results for each of the second detection circuits 22a to 22c are used to make any of the contactors 61a to 63a, 61b. It can be specified whether ~ 63b is fixed.

(Other embodiments)
The present invention is not limited to the above embodiment, and may be implemented, for example, as follows. In addition, below, the same code | symbol is attached | subjected to the part which is mutually the same or equal in each embodiment, and the description is used about the part of the same code | symbol.

  In the ground fault determination process, the second detection circuit 22 may be used. That is, during the ground fault detection period, the AC signal may be output from the second oscillation circuit 221, and the presence or absence of the ground fault may be detected based on the AC signal input through the second filter 224.

  ・ In the fixation determination process, whether the AC signals are output from the two detection circuits 21 and 22 or the AC signals are output from one of the detection circuits 21 and 22 during the fixation determination period depending on the presence or absence of the ground fault (That is, the process has shifted to either step S23 or step S29). As another example, regardless of the presence or absence of a ground fault, an alternating current signal may be output from the two detection circuits 21 and 22 during the fixation determination period to determine the presence or absence of the ground fault.

  For example, in this case, when the ground fault is detected only on the side of the electric load 12 during the fixation determination period (when only the peak value of the AC signal input through the first detection circuit 21 is lower than the ground fault judgment value) ), The controller 23 determines that there is a ground fault and that there is no sticking. When the ground fault is detected only on the battery 11 side during the fixation determination period (when only the peak value of the AC signal input through the second detection circuit 22 is lower than the ground fault determination value), the control device No. 23 determines that there is a ground fault and no sticking. In addition, when ground faults are detected on both sides during the fixation determination period (when the peak value of any AC signal is lower than the ground fault determination value), the control device 23 determines that there is a ground fault and that there is adhesion. Do.

  Moreover, when ground fault is not detected on both sides during the fixation determination period (when the peak value of any AC signal is equal to or greater than the ground fault judgment value), the control device 23 determines that there is no ground fault. Then, if the ground fault is not detected on both sides during the fixation determination period, the control device 23 causes the first detection circuit 21 to output an alternating current signal after the presence or absence of the ground fault, and the second alternating current signal The determination of sticking is made based on whether or not the input can be made through the circuit 22.

  DESCRIPTION OF SYMBOLS 11, 11a-11c ... Battery, 12 ... Electric load, 13a, 13b, 61a-63a, 61b- 63 ... Contactor, 20 ... Abnormality detection apparatus, 21 ... 1st detection circuit, 22, 22a-22c ... 2nd detection circuit , 23 ... control device.

Claims (4)

In a detection device (20) for detecting a ground fault in an electrical path between a DC power supply (11, 11a-11c) and an electrical load (12),
A first detection unit (21) provided closer to the electrical load than the switches (13a, 13b, 61a to 63a, 61b to 63b) provided in the electrical route, and detecting a ground fault of the electrical route;
A second detection unit (22, 22a to 22c) which is provided closer to the DC power supply than the switch and detects a ground fault of the electric path;
A ground fault determination unit (23) that determines whether or not a ground fault has occurred in the electrical path based on the detection results of the first detection unit and the second detection unit;
When the ground fault is detected by the ground fault determination unit, the switch is detected based on the detection of the ground fault by the first detection unit and the second detection unit in a state where the open control of the switch is executed. And a sticking determination unit (23) that determines that the pin is sticking. The first detection unit and the second detection unit are configured to be able to input and output signals to the electrical path,
The fixation determination unit detects one of the first detection unit and the second detection unit in a state where the open control of the switch is performed when the ground determination is not detected by the ground determination unit. The detection device according to claim 1, wherein the switch is determined to be stuck based on the fact that the signal output from the input unit is input by the other detection unit. The ground fault judging unit
When a ground fault is detected by any one of the first detection unit and the second detection unit in a state where the closing control of the switch is executed, it is determined that the ground fault is generated.
When a ground fault is not detected by any one of the first detection unit and the second detection unit in a state in which the closing control of the switch is executed, it is determined that the ground fault has not occurred. Or the detection apparatus as described in 2. A plurality of the DC power supplies (11a to 11c) are connected in parallel to the electric load,
The switches (61a to 63a, 61b to 63b) and the second detection units (22a to 22c) are provided for each of the plurality of DC power supplies,
The detection device according to any one of claims 1 to 3, wherein the fixation determination unit determines whether or not the switch is fixed by using a detection result of each of the second detection units.

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