JP2018084486A - Abnormality determination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abnormality determination device capable of accurately determining existence of abnormality on an abnormality detection circuit which detects abnormality on an objective electronic circuit and outputs an abnormality generation signal.SOLUTION: An ECU (electronic control unit) determines existence/absence of abnormality on an abnormality detection circuit which includes an electronic component implemented on a base plate being soldered, and which detects an abnormality on an inverter and outputs an abnormality generation signal. In a state that temperature of the abnormality detection circuit is within a predetermined temperature range, when a pulse which has a pulse width shorter than output continuation time of the abnormality generation signal is input from the abnormality detection circuit plural times, the ECU determines that a temporal abnormality which may cause a failure has generated on the abnormality detection circuit and generates an alarm.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an abnormality determination device that detects an abnormality in an abnormality detection circuit that detects an abnormality in a target electronic circuit and outputs an abnormality occurrence signal.

  Conventionally, as an electronic circuit board on which electronic parts are mounted by solder, monitoring means for detecting breakage by monitoring the state of a solder joint between the electronic circuit board and the electronic component between two points included in the solder joint (For example, refer to Patent Document 1). This electronic circuit board monitoring means periodically measures the voltage or resistance between two points of one solder joint, and when the voltage value or resistance value suddenly increases, the solder joint between the two points is not detected. Considered to have broken.

JP 2009-257863 A

  However, in the electronic circuit board as described above, a pulse having a relatively short pulse width may be generated due to radio waves traveling around, and the monitoring means causes the pulse to be caused by breakage of the solder joint. There is a risk of misjudging it.

  In view of this, the main object of the present disclosure is to make it possible to accurately determine whether there is an abnormality in an abnormality detection circuit that detects an abnormality in a target electronic circuit and outputs an abnormality occurrence signal.

  The abnormality determination device according to the present disclosure includes an electronic component mounted on a substrate with solder and detects an abnormality in a target electronic circuit and outputs an abnormality occurrence signal to determine whether there is an abnormality in the abnormality detection circuit. A failure occurs when a pulse having a pulse width shorter than the output duration of the abnormality occurrence signal is input from the abnormality detection circuit a plurality of times while the temperature of the abnormality detection circuit is within a predetermined temperature range. It is determined that a temporary abnormality that may be connected to the abnormality detection circuit has occurred, and a warning is generated.

  As described above, when the abnormality of the abnormality detection circuit is determined, the temperature of the abnormality detection circuit at the time of pulse input is taken into account, which is caused by the thermal expansion of the solder joint that may lead to failure of the abnormality detection circuit. It is possible to accurately distinguish a pulse from a pulse generated due to a radio wave traveling around. As a result, according to this abnormality determination device, it is possible to accurately determine whether there is an abnormality in the abnormality detection circuit that detects an abnormality in the target electronic circuit and outputs an abnormality occurrence signal.

It is a schematic structure figure of vehicles containing the electronic controller which is an abnormality judging device of this indication. It is a control block diagram which shows the structure relevant to the abnormality determination of the abnormality detection circuit in the vehicle of FIG. It is a flowchart which illustrates the routine for determining the presence or absence of abnormality of an abnormality detection circuit.

  1 is a schematic configuration diagram of an electric vehicle 1 as a vehicle including an electronic control device (hereinafter referred to as “ECU”) 10 that is an abnormality determination device of the present disclosure. In addition, the motor MG connected to the left and right drive wheels DW via a differential gear or the like, the power storage device (battery) 2, and connected to the power storage device 2 via the system main relay 3 and drives the motor MG. And a power control unit (hereinafter referred to as “PCU”) 4.

  Motor MG is configured as a three-phase synchronous motor, and exchanges power with power storage device 2 via PCU 4. Motor MG is driven by the electric power from power storage device 2 to output a traveling torque to driving wheel DW, and also outputs a regenerative braking torque to driving wheel DW during braking of electric vehicle 1. Further, the motor MG is provided with a rotation angle sensor (resolver) 6 for detecting the rotation angle θ (rotation position) of the rotor. In the present embodiment, the power storage device 2 is a lithium ion secondary battery or a nickel hydride secondary battery. As illustrated, the system main relay 3 includes a positive side relay connected to the positive side power line PL and a negative side relay connected to the negative side power line NL.

  The PCU 4 includes an inverter 40 that is an electronic circuit that drives the motor MG, a voltage conversion module (step-up / down converter) 41 that can step up the power from the power storage device 2 and step down the power from the motor MG, and a smoothing capacitor 42. And 43, and a PCU case 4C for housing them. The inverter 40 includes six transistors (for example, insulated gate bipolar transistors (IGBT)) Tr1, Tr2, Tr3, Tr4, Tr5, and Tr6 as switching elements, and six transistors 6 connected in parallel to the transistors Tr1 to Tr6 in the reverse direction. It consists of two diodes D1, D2, D3, D4, D5 and D6. The six transistors Tr1 to Tr6 are paired in pairs so as to be on the source side and the sink side with respect to the positive power line PL and the negative power line NL. In addition, each of the three-phase coils (U-phase, V-phase, W-phase) of the electric motor MG is electrically connected to each connection point between the two transistors that form a pair.

  The voltage conversion module 41 includes, for example, two transistors that are insulated gate bipolar transistors (IGBT), two diodes connected in parallel in opposite directions with respect to each transistor, and a reactor (both not shown). . One end of the reactor is electrically connected to the positive terminal of the power storage device 2 via the system main relay 3, and the other end of the reactor is connected to the emitter of one transistor (upper arm) and the other transistor (lower arm). The collector is electrically connected. Further, the collector of the one transistor (upper arm) is electrically connected to the positive-side power line PL, and the emitter of the other transistor is electrically connected to the negative-side power line NL. Further, the smoothing capacitor 42 is installed between the system main relay 3 and the voltage conversion module 41, and smoothes the voltage on the power storage device 2 side of the voltage conversion module 41, that is, the pre-boosting voltage VL. The smoothing capacitor 43 is installed between the voltage conversion module 41 and the inverter 40 and smoothes the boosted voltage VH boosted by the voltage conversion module 41.

  Further, the PCU 4 includes a laminated cooler (not shown) for cooling the inverter 40, the voltage conversion module 41, the smoothing capacitors 42 and 43, and the refrigerant pump P connected to the laminated cooler. The refrigerant pump P sucks a cooling medium such as LLC (Long Life Coolant) from a reservoir tank (not shown) and pumps it to the stacked cooler. The cooling medium that has cooled the inverter 40 and the like passes through the stacked cooler and flows into a radiator (not shown), and the cooling medium cooled by the radiator is returned to the reservoir tank.

  As shown in FIG. 2, the ECU 10 includes a microcomputer 11 having a CPU, a ROM, a RAM, an input / output interface and the like, a storage device 12 such as an EEPROM or an SRAM, various drive circuits (not shown), and the like. The ECU 10 determines the rotation angle θ of the motor MG detected by the rotation angle sensor 6, the pre-boosting voltage VL and the post-boosting voltage VH detected by a voltage sensor (not shown), and each phase of the motor MG detected by a current sensor (not shown). Enter the value of the flowing current (phase current). Based on these input signals, the ECU 10 generates a switching control signal to each transistor of the inverter 40 and the voltage conversion module 41, and performs switching control of the inverter 40 and the voltage conversion module 41. Further, the ECU 10 controls the opening and closing of the system main relay 3. Further, the ECU 10 is connected to a control unit of the display device 7 such as a liquid crystal display having a warning display area, and outputs various command signals to the control unit.

  As shown in FIG. 2, the ECU 10 (microcomputer 11) has an abnormality for detecting an abnormality in the temperature detection circuit 44 that detects the refrigerant temperature Tc that is the temperature of the cooling medium that has cooled the PCU 4 and the inverter 40. A detection circuit 45 is connected. For example, when an overcurrent flows through at least one of the transistors Tr1 to Tr6, the abnormality detection circuit 45 outputs an abnormality occurrence signal (high level signal) FINV having a pulse width (output duration) of, for example, about 50 to 150 msec. This is output to the ECU 10. When the ECU 10 receives the abnormality occurrence signal FINV from the abnormality detection circuit 45, the ECU 10 considers that an abnormality has occurred in the inverter 40, turns off all the transistors Tr1 to Tr6 of the inverter 40, and stops the traveling of the electric vehicle 1. Subsequent travel is prohibited.

  In the present embodiment, the abnormality detection circuit 45 includes a plurality of driver ICs 45a connected to overcurrent detection elements provided in the corresponding transistors Tr1 to Tr6, and a plurality of latch circuits 45b connected to the corresponding driver ICs 45a. And an OR circuit (not shown). The abnormality detection circuit 45 is configured by mounting a plurality of electronic products constituting the driver IC 45a, the latch circuit 45b, the OR circuit, and the like on the substrate 45c with solder. The abnormality detection circuit 45 is disposed in the PCU case 4C of the PCU 4 and is cooled by a cooling medium that circulates in the above-described stacked cooler. The abnormality detection circuit 45 may be configured to detect that an overvoltage is applied to at least one of the transistors Tr1 to Tr6 and output an abnormality occurrence signal FINV, and detects the overheating of the inverter 40. The abnormality occurrence signal FINV may be output.

  Here, in the abnormality detection circuit 45 as described above, when the solder joint between the latch circuit 45b and the ECU 10 is thermally expanded, a pulse (with a pulse width shorter than the abnormality occurrence signal FINV due to temporary short-circuit or open ( Hereinafter, the “short pulse” is generated in the abnormality detection circuit 45, and the short pulse (high level signal) is transmitted from the abnormality detection circuit 45 to the ECU 10. Further, when the solder joint portion is thermally expanded, the abnormality detection circuit 45 may possibly fail due to accumulation of thermal stress in the solder joint portion. Furthermore, if the abnormality occurrence signal FINV is erroneously output due to the failure of the abnormality detection circuit 45, the traveling of the electric vehicle 1 is stopped, and it may be determined that the inverter 40 needs to be replaced for inspection and maintenance. . Therefore, a short pulse generated due to thermal expansion of the solder joint is detected separately from the abnormality occurrence signal FINV, and when the short pulse is detected, a temporary abnormality that may lead to failure is detected as an abnormality. It is preferable to warn the driver that the circuit 45 has occurred.

  However, if a relatively strong radio wave for wireless communication, for example, is traveling around the abnormality detection circuit 45, a pulse having a pulse width shorter than that of the abnormality occurrence signal FINV (hereinafter, “ A short pulse ") is generated in the abnormality detection circuit 45, and the short pulse (high level signal) is also transmitted from the abnormality detection circuit 45 to the ECU 10. The short pulse caused by the radio wave is not caused by an abnormality of the abnormality detection circuit 45 and does not directly lead to a failure of the abnormality detection circuit 45. Therefore, short pulses generated due to thermal expansion of solder joints and generated due to radio waves so as not to erroneously determine the presence or absence of temporary abnormalities that may lead to failure in the abnormality detection circuit 45 It is necessary to accurately distinguish the short pulse. Therefore, the ECU 10 determines whether there is an abnormality in the abnormality detection circuit 50 as described below.

  FIG. 3 is a flowchart illustrating a routine for determining whether the abnormality detection circuit 50 in the electric vehicle 1 is abnormal. The routine of FIG. 3 is repeatedly executed by the ECU 10 (microcomputer 11) basically every predetermined time (for example, about 500 μSec) while the electric vehicle 1 is activated.

  At the start of the routine of FIG. 3, the ECU 10 first executes a determination process as to whether or not a high level signal has been input from the abnormality detection circuit 45 (step S100). When it is determined that the high level signal is input from the abnormality detection circuit 45 (step S110: YES), the ECU 10 measures the duration of the input high level signal and determines whether the high level signal has been switched to the low level. Determination is made (step S120). When the ECU 10 determines that the high level signal has changed to a low level (step S130: YES), the ECU 10 compares the duration of the high level signal measured in step S120 with a predetermined threshold value to input the high level signal. It is determined whether the level signal is a short pulse or an abnormality occurrence signal FINV (step S140).

  In step S140, when it is determined that the duration of the high level signal is shorter than the threshold value and the input high level signal is a short pulse, the ECU 10 detects the refrigerant temperature detected by the temperature detection circuit 44 at that time. Tc is acquired as the current value of the substrate temperature (temperature of the substrate 45c) Tcb of the abnormality detection circuit 45, and the previous value of the substrate temperature Tcb stored in the storage device 12 is acquired (step S150). The previous value of the substrate temperature Tcb stored in the storage device 12 is the refrigerant detected by the temperature detection circuit 44 when the ECU 10 inputs a short pulse from the abnormality detection circuit 45 before the current execution of this routine. The temperature Tc. Next, the ECU 10 determines whether or not the current value and the previous value of the substrate temperature Tcb are included in a predetermined temperature range (step S160). In step S160, when the absolute value of the difference between the current value of the substrate temperature Tcb and the previous value is equal to or less than a predetermined temperature difference (for example, a value of 10 ° C. or less), the ECU 10 When it is determined that the previous value is included in the predetermined temperature range and the absolute value exceeds the temperature difference, the current value and the previous value of the substrate temperature Tcb are not included in the predetermined temperature range. Is determined.

  When it is determined that the current value and the previous value of the substrate temperature Tcb are included in the predetermined temperature range (step S160: YES), the ECU 10 increments a counter (not shown) (step S170), It is determined whether or not the count value C is equal to or greater than a predetermined threshold value Cref (for example, twice) (step S180). When it is determined that the count value C is equal to or greater than the threshold value Cref (step S180: YES), the ECU 10 regards that a temporary abnormality that may lead to a failure has occurred in the abnormality detection circuit 45, and turns on the temporary abnormality flag. At the same time, a command signal is output to the control unit of the display device 7 so as to light a predetermined warning lamp on the display device 7 (step S190).

  That is, when an affirmative determination is made in step S180, the ECU 10 inputs short pulses a plurality of times from the abnormality detection circuit 45 in a state where the substrate temperature Tcb (temperature of the abnormality detection circuit 45) is included in the predetermined temperature range. It will be. In addition, it is highly possible that the factor causing the short pulse to be generated a plurality of times in a state where the substrate temperature Tcb is within the predetermined temperature range is thermal expansion of the solder joint. And when a solder joint part thermally expands, there exists a possibility that the abnormality detection circuit 45 may cause a failure by accumulation | storage of the thermal stress to the said solder joint part. For this reason, when an affirmative determination is made in step S180, as described above, the temporary abnormality flag is turned on in step S190, and a predetermined warning lamp on the display device 7 is turned on. Accordingly, it is possible to prevent the electric vehicle 1 from being stopped due to a failure of the abnormality detection circuit 45 and to promote replacement of the abnormality detection circuit 45 to avoid replacement of the more expensive inverter 40. . After the process of step S190, the ECU 10 updates the previous value of the substrate temperature Tcb stored in the storage device 12 with the refrigerant temperature Tc acquired in step S150 (step S200), and once ends this routine.

  On the other hand, when it is determined in step S160 that the current value and the previous value of the substrate temperature Tcb are not included in the predetermined temperature range (step S160: NO), and in step S180, the count value C is less than the threshold value Cref. If it is determined that there is (step S180: NO), the ECU 10 executes the process of step S200 without executing the processes of steps S170 to S190, and temporarily terminates this routine. That is, if a negative determination is made in step S160 or S180, is the substrate temperature Tcb (temperature of the abnormality detection circuit 45) different to some extent between the time when the current short pulse is generated and the time when the previous short pulse is generated? Since the inputted short pulse is a single shot, it is highly likely that the short pulse is generated due to the above-mentioned radio wave. For this reason, when a negative determination is made in step S160 or S180, the processes of steps S170 to S190 are skipped as described above. As a result, the short pulse caused by the thermal expansion of the solder joint and the short pulse caused by the radio wave are accurately distinguished, and it is erroneously determined that a temporary abnormality has occurred in the abnormality detection circuit 45. It becomes possible to suppress.

  When it is determined in step S110 that the high level signal is not input from the abnormality detection circuit 45 (step S110: NO), the ECU 10 clears the duration of the high level signal (step S125), The routine is temporarily terminated. Further, when it is determined in step S130 that the high level signal has not changed to the low level despite the elapse of time longer than the pulse width of the abnormality occurrence signal FINV (step S130: NO), the ECU 10 detects abnormality. It is assumed that the high level signal is continuously output due to the failure of the circuit 45, the abnormality detection circuit failure flag is turned on (step S145), and this routine is once ended. After the abnormality detection circuit failure flag is turned on, a predetermined warning lamp on the display device 7 is turned on, and traveling of the electric vehicle 1 is allowed only under predetermined conditions. In step S140, when it is determined that the duration of the high level signal is equal to or longer than the threshold value and the input high level signal is the abnormality occurrence signal FINV, the ECU 10 regards that an abnormality has occurred in the inverter 40. After turning on the inverter abnormality flag (step S155), this routine is temporarily terminated. After the inverter abnormality flag is turned on, a predetermined warning lamp on the display device 7 is turned on, all the transistors Tr1 to Tr6 of the inverter 40 are turned off, the travel of the electric vehicle 1 is stopped, and the subsequent Driving is prohibited.

  As described above, the ECU 10 as the abnormality determination device includes an electronic component such as the driver IC 45a mounted on the substrate 45c with solder and detects an abnormality of the inverter 40 that is the target electronic circuit, thereby generating an abnormality occurrence signal. It is determined whether there is an abnormality in the abnormality detection circuit 45 that outputs FINV. The ECU 10 has a pulse width shorter than the pulse width (output duration) of the abnormality occurrence signal FINV from the abnormality detection circuit 45 in a state where the substrate temperature Tcb (temperature of the abnormality detection circuit 45) is included in the predetermined temperature range. When a short pulse is input a plurality of times (steps S150 to S180), it is determined that a temporary abnormality that may cause a failure has occurred in the abnormality detection circuit 45, and a warning is generated (step S190). As described above, when the abnormality is detected in the abnormality detection circuit 45, the temperature of the abnormality detection circuit 45 at the time of inputting a short pulse is taken into consideration, so that the thermal expansion of the solder joint that may lead to the failure of the abnormality detection circuit 45 is caused. It is possible to accurately distinguish the short pulse generated due to the short pulse generated due to the radio wave traveling around. As a result, it is possible to accurately determine whether there is an abnormality in the abnormality detection circuit 45 that detects an abnormality in the inverter 40 and outputs the abnormality occurrence signal FINV.

  The storage device 12 may be built in the microcomputer 11. In the above embodiment, the refrigerant temperature Tc detected by the temperature detection circuit 44 is substituted for the substrate temperature Tcb of the abnormality detection circuit 45, but it goes without saying that the temperature of the substrate 45c may be measured. Further, the function of the ECU 10 may be distributed to a plurality of electronic control devices. The vehicle to which the invention of the present disclosure is applied is not limited to the electric vehicle 1. That is, the invention of the present disclosure may be a two-motor type (series parallel type) hybrid vehicle having a planetary gear for power distribution, a one-motor type hybrid vehicle, or a series type hybrid vehicle. It may be a parallel hybrid vehicle or a plug-in hybrid vehicle.

  And the invention of this indication is not limited to the said embodiment at all, and it cannot be overemphasized that various changes can be made within the range of the extension of this indication. Furthermore, the above-described embodiment is merely a specific form of the invention described in the Summary of Invention column, and does not limit the elements of the invention described in the Summary of Invention column.

  The invention of the present disclosure can be used in an abnormality detection circuit that detects an abnormality in an electronic circuit and outputs an abnormality occurrence signal, a manufacturing industry of the abnormality determination device, and the like.

  DESCRIPTION OF SYMBOLS 1 Electric vehicle, 2 Power storage device, 3 System main relay, 4 Electric power control unit (PCU), 4C PCU case, 6 Rotation angle sensor, 7 Display apparatus, 10 Electronic control unit (ECU), 11 Microcomputer, 12 Storage device, 40 inverter, 41 voltage conversion module, 42, 43 smoothing capacitor, 44 temperature detection circuit, 45 abnormality detection circuit, 45a driver IC, 45b latch circuit, 45c substrate, D1, D2, D3, D4, D5, D6 diode, DW drive Wheel, MG motor, PL positive power line, NL negative power line, Tr1, Tr2, Tr3, Tr4, Tr5, Tr6 transistors.

Claims (1)

An abnormality determination apparatus that includes an electronic component mounted on a substrate with solder and detects an abnormality of an abnormality detection circuit that detects an abnormality of an electronic circuit to be output and outputs an abnormality occurrence signal,
When a pulse having a pulse width shorter than the output duration of the abnormality occurrence signal is input a plurality of times from the abnormality detection circuit in a state where the temperature of the abnormality detection circuit is included in a predetermined temperature range, there is a risk of failure. An abnormality determination device characterized by generating a warning by determining that a temporary abnormality has occurred in the abnormality detection circuit.

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