JP5949584B2 - Driving device for switching element - Google Patents

Description

  The present invention relates to a driving device for a switching element provided with diagnostic means for diagnosing that the switching element has deteriorated.

  As this type of device, as can be seen in Patent Document 1 below, a device that diagnoses the presence or absence of deterioration of a switching element (IGBT) that constitutes an inverter is known. This apparatus will be described in detail. Test power having a predetermined frequency and current value is output from the inverter by an on / off operation of switching elements constituting the inverter. Then, under the situation where the test power is output from the inverter, the thermal resistance between the constituent members of the switching element is calculated based on the detected value of the temperature sensor that detects the temperature of the switching element. When it is determined that the calculated thermal resistance exceeds the threshold value, it is diagnosed that the switching element is deteriorated.

JP 2009-225541 A

  Here, in the switching element deterioration diagnosis method described in Patent Document 1, in order to output test power having a specific frequency and current value from the inverter in order to diagnose the presence or absence of deterioration of the switching element, The driving state is required to be a specific driving state. For this reason, there is a concern that the opportunity for the deterioration diagnosis of the switching element is restricted.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a switching element driving device capable of avoiding the restriction of the opportunity for diagnosis of deterioration of the switching element.

In order to solve the above problems, the present invention provides a drive signal output means (14) for outputting an ON drive signal for turning on the switching element (S * #) or an OFF drive signal for turning off the switching element (S * #), and the drive signal output. Drive means (22) for driving the switching element based on the drive signal output from the means, and storage means for storing a threshold time which is a drive time of the switching element assumed to be deteriorated (24), a clocking means for clocking the drive time of the switching element, and the switching when the drive time counted by the clocking means is greater than or equal to the threshold time stored in the storage means Diagnostic means for diagnosing that the element has deteriorated.

  In the above-mentioned invention, it is possible to diagnose that the switching element is deteriorated under the situation where the switching element is driven based on the drive signal by providing the storage means, the timing means, and the diagnosis means. Therefore, for example, it is possible to diagnose whether or not the switching element is deteriorated without changing the driving state of the switching element to a specific driving state. That is, it is possible to diagnose whether or not the switching element is deteriorated while avoiding the restriction of the opportunity for the deterioration diagnosis of the switching element.

The block diagram of the control system concerning 1st Embodiment. The block diagram of the drive IC etc. concerning the embodiment. The flowchart which shows the procedure of the degradation diagnosis process concerning the embodiment. The figure which shows the setting aspect of the threshold time concerning the embodiment. The time chart which shows an example of the deterioration diagnosis process concerning the embodiment. The flowchart which shows the procedure of the deterioration diagnosis process concerning 2nd Embodiment. The flowchart which shows the procedure of the degradation diagnosis process concerning 3rd Embodiment. The figure which shows the setting aspect of the threshold time concerning the embodiment. The flowchart which shows the procedure of the alerting | reporting process at the time of 4th Embodiment. The figure which shows the setting aspect of the 1st, 2nd threshold time concerning the embodiment. The time chart which shows an example of the alerting | reporting process at the time of the embodiment. FIG. 10 is a configuration diagram of a drive IC and the like according to a fifth embodiment. 18 is a flowchart showing a procedure of drive time transmission processing according to the sixth embodiment. The time chart which shows the transmission method of the drive time concerning the embodiment. The figure which shows the limiting method of the torque command value concerning the embodiment. The time chart which shows the transmission method of the drive time concerning 7th Embodiment. The figure which shows the limiting method of the torque command value concerning the embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a switching element driving device according to the present invention is applied to a hybrid vehicle including a rotating machine and an internal combustion engine as an in-vehicle main machine will be described with reference to the drawings.

  As shown in FIG. 1, the motor generator 10 (rotating machine) is an in-vehicle main machine, and is connected to drive wheels (not shown). The motor generator 10 is connected to a high voltage battery 12 via an inverter IV and a boost converter (not shown). The inverter IV includes a series connection body of a high potential side switching element and a low potential side switching element connected in parallel to the high voltage battery 12. Specifically, the inverter IV includes a serial connection body of switching elements Sup and Sun, a serial connection body of switching elements Svp and Svn, and a serial connection body of switching elements Swp and Swn. Connection points of these series connection bodies are respectively connected to the U, V, and W phases of the motor generator 10.

  In the present embodiment, a voltage control type is used as the switching element S * # (* = u, v, w; # = p, n), and more specifically, an IGBT is used. ing. In addition, a free wheel diode D * # is connected in antiparallel to each of the switching elements S * #.

  The control device 14 is configured with a low-voltage battery 16 as a power source and mainly a microcomputer, and controls the control amount (torque) of the motor generator 10 to its command value (torque command value Trq *) by operating the inverter IV and the boost converter. It has the function to do. Specifically, the control device 14 outputs a drive signal generated by software processing to the switching element S * # via the drive unit DU * #, thereby turning on / off the switching element S * #. Here, the high-potential side drive signal g * p and the corresponding low-potential side drive signal g * n are complementary to each other. In other words, the high-potential side switching element S * p and the corresponding low-potential side switching element S * n are alternately turned on. In the present embodiment, the control device 14 constitutes “driving signal output means”.

  Incidentally, the torque command value Trq * is input to the control device 14 from a host control device that supervises vehicle control. The torque command value Trq * is a part of the vehicle torque command value instructed by the operation of the accelerator operation member by the user by the motor generator 10.

  The interface 18 electrically insulates between a high voltage system including the high voltage battery 12, the inverter IV and the motor generator 10 and a low voltage system including the low voltage battery 16 and the control device 14, and between them. It has a function of transmitting signals. In the present embodiment, the interface 18 includes an optical insulating element (photocoupler). In the present embodiment, the low voltage system corresponds to the “first region”, and the high voltage system corresponds to the “second region”. Further, the reference potential VstL of the low voltage system is different from the reference potential VstH of the high voltage system. In the present embodiment, the reference potential VstH of the high voltage system is set to the negative potential of the high voltage battery 12, and the vehicle body potential in which the reference potential VstL of the low voltage system is the median value of the positive potential and the negative potential of the high voltage battery 12. Is set to

  Next, the configuration of the drive unit DU * # and the like according to the present embodiment will be described with reference to FIG.

  As shown in the figure, the drive unit DU * # includes a drive IC 20 that is a semiconductor integrated circuit integrated into one chip. The drive IC 20 includes a drive control unit 22 and a memory 24. Specifically, a constant voltage power supply 28 having a predetermined terminal voltage VH (for example, 15 V) is connected to the first terminal T1 of the drive IC 20 via the charging resistor 26. The constant voltage power supply 28 is a power supply for generating a voltage to be applied to the switching control terminal (gate) of the switching element S * #. The memory 24 constitutes “storage means” capable of holding information without supplying power, and is specifically a nonvolatile memory (for example, an EEPROM (registered trademark) or a flash memory). In FIG. 2, the free wheel diode D * # is not shown. In the present embodiment, the drive control unit 22 constitutes “driving means”.

  The first terminal T1 is connected to the second terminal T2 of the drive IC 20 via a P-channel MOSFET (charging switching element 30). The second terminal T2 is connected to the gate of the switching element S * #. The gate of the switching element S * # is connected to the third terminal T3 of the drive IC 20 via the discharging resistor 32. The third terminal T3 is an N-channel MOSFET (discharging switching element 34). To the fourth terminal T4 of the drive IC 20. The fourth terminal T4 is connected to the output terminal (emitter) of the switching element S * #.

  A temperature sensitive diode SD * # for detecting the temperature of the switching element S * # (hereinafter, element temperature) is provided in the vicinity of the switching element S * #. The voltage between the terminals of the temperature sensitive diode SD * # is taken into the temperature detection unit 36 provided in the drive IC 20. The temperature detection unit 36 outputs the element temperature Sd calculated based on the inter-terminal voltage to the drive control unit 22. Note that the voltage across the terminals of the temperature sensitive diode SD * # and the actual element temperature have a negative correlation. In the present embodiment, the temperature sensitive diode SD * #, the switching element S * #, and the freewheel diode D * # are integrated. Specifically, these elements are packaged to constitute a power card PC.

  A drive signal g * # output from the control device 14 is input to the drive control unit 22 via the first photocoupler 18a constituting the interface 18 and the fifth terminal T5 of the drive IC 20. The drive control unit 22 performs a gate charge charging / discharging process based on the input drive signal g * #. Specifically, the charge processing of the gate charge will be described. When the drive signal g * # is turned on, the charging switching element 30 is turned on and the discharging switching element 34 is turned off. Thereby, switching element S * # is switched to an ON state. That is, switching element S * # is driven. On the other hand, the gate discharging process will be described. When the driving signal g * # is turned off, the charging switching element 30 is switched to the off operation, and the discharging switching element 34 is switched to the on operation. Thereby, switching element S * # is switched to an OFF state. That is, the driving of the switching element S * # is stopped.

  The drive control unit 22 also performs local shutdown processing. In this process, when it is determined that the element temperature Sd output from the temperature detection unit 36 exceeds the threshold temperature, the switching element S * # is forcibly stopped by assuming that the switching element S * # is in an overheated state. It is processing. According to this process, the switching element S * # can be quickly turned off, and a situation in which the reliability of the switching element S * # is greatly reduced due to overheating of the switching element S * # can be avoided.

  When the local shutdown process is performed, the drive control unit 22 configures the interface 18 with the sixth terminal T6 of the drive IC 20 with the failure signal FL indicating that an abnormality has occurred in the switching element S * #. Processing to transmit to the control device 14 via the second photocoupler 18b is also performed. In the present embodiment, the fail signal FL indicates that the abnormality has occurred due to the logic “L”.

  The drive control unit 22 further performs a process of converting the element temperature Sd output from the temperature detection unit 36 into a time ratio signal (Duty signal DS) and outputting it to the control device 14. Here, the duty signal DS is transmitted to the control device 14 via the seventh terminal T7 of the drive IC 20 and the third photocoupler 18c constituting the interface 18. When the control device 14 determines that the temperature of the switching element S * # is high based on the duty signal DS, the power save process for limiting the torque command value Trq * with the specified torque Tγ to limit the output of the motor generator 10. I do. According to this process, when the torque command value Trq * output from the host control device exceeds the specified torque Tγ, the control device 14 sets the torque command value Trq * as the specified torque Tγ. As a result, the driving of the switching element S * # is limited to limit the collector current Ice, and overheating of the switching element S * # can be avoided.

  In this embodiment, the second photocoupler 18b electrically isolates the low voltage system from the high voltage system, and transmits the signal from the high voltage system to the low voltage system. Configure. Further, the seventh terminal T7 and the third photocoupler 18c are actually provided corresponding to only one of the switching elements S * # constituting the inverter IV. Specifically, these switching elements S * # are provided corresponding to those that are assumed to have the highest element temperature. In the present embodiment, the seventh terminal T7 and the third photocoupler 18c are provided corresponding to the switching element Sup.

  In the present embodiment, the drive IC 20 and the power card PC are different from the first board 38a on which the control device 14 is provided, for the purpose of providing power elements such as switching elements S * # on a common board. The second substrate 38b is provided. Note that the first substrate 38a and the second substrate 38b are electrically connected through, for example, a collector. In the present embodiment, the first photocoupler 18a, the second photocoupler 18b, and the third photocoupler 18c are provided on the second substrate 38b.

  Next, the deterioration diagnosis process for the switching element S * # according to the present embodiment will be described.

  FIG. 3 shows the procedure of the deterioration diagnosis process. This process is repeatedly executed by the drive control unit 22 at a predetermined cycle, for example. Since the drive control unit 22 according to the present embodiment is hardware, the processing shown in FIG. 3 is actually executed by a logic circuit.

  In this series of processing, first, in step S10, it is determined whether or not the value of the diagnostic flag F is “0”. Here, the diagnosis flag F indicates that the switching element S * # is not deteriorated by “0”, and indicates that it is deteriorated by “1”. The initial value of the diagnosis flag F is set to “0”.

  When an affirmative determination is made in step S10, the process proceeds to step S12 to determine whether or not the drive signal g * # input to the drive control unit 22 is an on drive signal.

  If an affirmative determination is made in step S12, the process proceeds to step S14, and the counter Cnt is incremented by one. In this embodiment, the counter Cnt corresponds to “driving time”, and the processing of this step constitutes “time measuring means”. In addition, the initial value of the counter Cnt (for example, the value at the time of product shipment) is set to “0”. In the present embodiment, the value of the counter Cnt is stored in a nonvolatile memory provided in the drive IC 20 for each calculation cycle. The nonvolatile memory may be the memory 24 or a memory different from the memory 24.

  In subsequent step S16, the element temperature Sd is detected. In the present embodiment, the process of this step, the temperature sensitive diode SD * #, and the temperature detection unit 36 constitute “temperature detection means”.

  In the subsequent step S18, an average temperature Save that is a time average value of the element temperature Sd in a period during which the ON drive signal is input is calculated. In the present embodiment, the average temperature Save is calculated as an addition value of the value obtained by dividing the element temperature Sd (n) detected in the current calculation cycle by the value of the counter Cnt and the average temperature α in the previous calculation cycle. . In this embodiment, the process of this step constitutes “average temperature calculation means”.

  In subsequent step S20, a threshold time Tth is set based on the average temperature Save. Specifically, as shown in FIG. 4, the threshold time Tth is set to be shorter stepwise as the average temperature Save is higher. The threshold time Tth is the driving time of the switching element S * # that is assumed to have deteriorated the switching element S * # (more specifically, the value of the counter Cnt corresponding to the driving time), and is stored in the memory 24. Yes. Here, in the present embodiment, the threshold time Tth is a counter value indicating the life (lifetime) of the switching element S * #. Note that the threshold time Tth may be specifically set using, for example, a map in which the average temperature Save and the threshold time Tth are related. In the present embodiment, the process of step S20 constitutes “threshold time setting means”.

  Returning to the description of FIG. 3, in the subsequent step S22, it is determined whether or not the value of the counter Cnt is equal to or greater than the threshold time Tth. Note that the value of the counter Cnt used in the processing of this step is the integrated value of the time during which the ON drive signal is input to the drive control unit 22 (in other words, the time during which the ON drive signal is output from the control device 14). Equivalent to the integrated value).

  If an affirmative determination is made in step S22, the process proceeds to step S24 to diagnose that the switching element S * # has deteriorated (that the life has passed) and set the value of the diagnosis flag F to “1”. To do. In the present embodiment, the processes in steps S22 and S24 constitute “diagnostic means”.

  When the process of step S24 is completed or when a negative determination is made in step S10, the process proceeds to step S26. In step S26, the logic of the fail signal FL is inverted to “L” to forcibly stop the switching element S * # and the notification that the switching element S * # has deteriorated. Notification instruction processing for giving an instruction is performed. Here, the forcible stop processing is specifically processing for causing the drive signal g * # output from the control device 14 to be an off drive signal.

  When the notification instruction process is performed, a process for turning on the warning lamp and a process for using the driving power source of the vehicle as an engine are performed by the host control device. Accordingly, it is possible to appropriately perform limp home until the vehicle reaches the repair shop, or to prompt the user to replace the inverter IV. Incidentally, the notification instruction processing of the processing of this step constitutes “notification instruction means”, and the forced stop processing constitutes “stop means”.

  If a negative determination is made in steps S12 and S22, or if the process in step S26 is completed, this series of processes is temporarily terminated.

  Next, FIG. 5 shows an example of the deterioration diagnosis process. Specifically, FIG. 5A shows the transition of the counter Cnt, and FIG. 5B shows the transition of the fail signal FL input to the control device 14.

  In the illustrated example, at time t1, the drive control unit 22 determines that the value of the counter Cnt is equal to or greater than the threshold time Tth. As a result, the control device 14 determines that the logic of the fail signal FL has been inverted from “H” to “L”, and the forced stop process and the notification instruction process are performed.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) When it is determined that the value of the counter Cnt is equal to or greater than the threshold time Tth, deterioration diagnosis processing for diagnosing that the switching element S * # is deteriorated is performed. According to this process, it is possible to diagnose that the switching element S * # is deteriorated under the situation where the switching element S * # is normally driven based on the drive signal g * #. For this reason, for example, unlike the technique described in Patent Document 1, it is diagnosed whether the switching element S * # is deteriorated without setting the driving state of the switching element S * # to a specific driving state. Can do. That is, it is possible to diagnose whether or not the switching element S * # is deteriorated while avoiding that the opportunity for diagnosing the deterioration of the switching element S * # is restricted.

  (2) The integrated value of the time during which the ON drive signal is input to the drive control unit 22 is measured by a counter. That is, the integrated value of the time when the ON drive signal is input and the drive time are synchronized. According to such a configuration, since the drive time can be measured without detecting the gate voltage Vge and the collector current Ice on the drive IC 20 side, the drive time can be measured with a simple configuration.

  (3) The threshold time Tth was set shorter as the average temperature Save was higher. The higher the element temperature in the situation where the switching element S * # is driven, the shorter the lifetime of the switching element S * #. For this reason, according to the method for setting the threshold time Tth according to the present embodiment, the threshold for diagnosing whether or not the switching element S * # is deteriorated can be set with high accuracy. Thereby, it is possible to diagnose with high accuracy whether or not the switching element S * # is deteriorated.

  (4) The drive control unit 22 and the memory 24 are provided in the single drive IC 20, and the drive IC 20 and the switching element S * # are provided in the second substrate 38b that is a common substrate. If the board provided with the switching element S * # is different from the board provided with the logic circuit that is the execution subject of the deterioration diagnosis process, if the board provided with the logic circuit is replaced for some reason, the time is counted by the counter. The driving time is reset. On the other hand, according to the present embodiment, even when the first substrate 38a is replaced for some reason, it is possible to suitably avoid a situation in which the measured drive time is reset, and the switching element It can be avoided that the deterioration diagnosis of S * # cannot be executed midway.

  (5) When it is diagnosed that the switching element S * # is deteriorated, a notification instruction process is performed to issue a notification instruction that the switching element S * # is deteriorated. Accordingly, it is possible to prompt the user to replace the inverter IV including the switching element S * #, and as a result, it is possible to avoid the vehicle being continuously used in a state where the reliability of the inverter IV is lowered.

  (6) When it is diagnosed that the switching element S * # is deteriorated, a forced stop process for forcibly stopping the driving of the switching element S * # is performed. Thereby, it can avoid that a vehicle is used continuously in the state which the reliability of inverter IV provided with switching element S * # fell.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In this embodiment, the post-processing when the switching element is diagnosed to be deteriorated is changed.

  FIG. 6 shows a procedure of deterioration diagnosis processing according to the present embodiment. This process is repeatedly executed by the drive control unit 22 at a predetermined cycle, for example. In FIG. 6, the same steps as those shown in FIG. 3 are given the same step numbers for the sake of convenience. Further, since the drive control unit 22 according to the present embodiment is hardware, the processing shown in FIG. 6 is actually executed by a logic circuit.

  In this series of processes, when the process of step S24 is completed or when a negative determination is made in step S10, the process proceeds to step S26a to instruct the control device 14 to execute the power save process instead of the forced stop process. Process. Thereby, the collector current Ice is limited. In the present embodiment, the power saving process of the process of this step constitutes a “limiter”.

  If a negative determination is made in steps S12 and S22, or if the process in step S26a is completed, the series of processes is temporarily terminated.

  According to the present embodiment described above, the following effects can be obtained in addition to the effects (1) to (5) of the first embodiment.

  (7) When it is diagnosed that the switching element S * # is deteriorated, a power saving process is performed. For this reason, collector current Ice can be limited, and the time until the drive time of switching element S * # reaches the lifetime can be extended. Thereby, for example, the time for performing limp home can be secured.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In this embodiment, the setting method of the threshold time Tth is changed.

  FIG. 7 shows the procedure of the deterioration diagnosis process. This process is repeatedly executed by the drive control unit 22 at a predetermined cycle, for example. In FIG. 7, the same steps as those shown in FIG. 3 are given the same step numbers for the sake of convenience. Further, since the drive control unit 22 according to the present embodiment is hardware, the processing shown in FIG. 7 is actually executed by a logic circuit.

  In this series of processes, after the process of step S18 is completed, the process proceeds to step S28, and the gate voltage Vge is detected under the situation where the ON drive signal is input to the drive control unit 22. In the present embodiment, the process in this step constitutes a “voltage detection unit”.

  In subsequent step S30, an average applied voltage Vave, which is a time average value of the gate voltage Vge during a period in which the ON drive signal is input, is calculated. In the present embodiment, similar to the method for calculating the average temperature Save, a value obtained by dividing the gate voltage Vge (n) detected in the current calculation cycle by the value of the counter Cnt, and the average applied voltage β in the previous calculation cycle. The average applied voltage Vave is calculated as an added value. In this embodiment, the process of this step constitutes “average voltage calculation means”.

  In the subsequent step S20a, a threshold time Tth is set based on the average temperature Save and the average applied voltage Vave. Specifically, as shown in FIG. 8, the threshold time Tth is set to be shorter stepwise as the average temperature Save is higher or the average applied voltage Vave is higher. Here, the reason why the average applied voltage Vave is used for setting the threshold time Tth is that the life of the switching element S * # tends to be shorter as the gate voltage Vge is higher when the switching element S * # is driven. It depends. The threshold time Tth may be specifically set using, for example, a map in which the average temperature Save, the average applied voltage Vave, and the threshold time Tth are related.

  Returning to the description of FIG. 7, the process proceeds to step S22 after the process of step S20a is completed.

  If a negative determination is made in steps S12 and S22, or if the process in step S26 is completed, this series of processes is temporarily terminated.

  According to this embodiment described above, in addition to the effects (1), (2), (4) to (6) of the first embodiment, the following effects can be obtained.

  (8) The threshold time Tth is set shorter as the average temperature Save is higher or the average applied voltage Vave is higher. According to such a setting method, the threshold value for diagnosing whether or not the switching element S * # is deteriorated can be set with higher accuracy. Thereby, it can be diagnosed with higher accuracy whether or not the switching element S * # is deteriorated.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, a startup notification instruction process is performed to notify that the switching element S * # is near the end of life immediately after startup of the inverter IV. In the present embodiment, the threshold time Tth is referred to as a first threshold time Tth1.

  FIG. 9 shows the procedure of the startup notification instruction process. This process is repeatedly executed by the drive control unit 22 at a predetermined cycle, for example. Since the drive control unit 22 according to the present embodiment is hardware, the processing shown in FIG. 9 is actually executed by a logic circuit.

  In this series of processes, first, in step S32, it is determined whether or not the inverter IV is in a starting state. This process is a process for determining whether or not it is immediately before the switching element S * # starts to be driven. Note that when the inverter IV is activated, for example, a period from when the ignition switch is turned on by the user until the switching element S * # starts to be turned on / off (usually driven) by the charging process and the discharging process (hereinafter referred to as normal driving). , The startup preparation period of the inverter IV).

  If an affirmative determination is made in step S32, the process proceeds to step S34 to determine whether or not the value of the counter Cnt is equal to or greater than the second threshold time Tth2. Here, the second threshold time Tth2 is a time that defines a degree of deterioration that is shorter than the first threshold time Tth1 and smaller than the degree of deterioration of the switching element S * # defined by the first threshold time Tth1. is there. Specifically, for example, the second threshold time Tth2 is set to about 80% of the first threshold time Tth1. The second threshold time Tth2 is stored in the memory 24 together with the first threshold time Tth1. Here, FIG. 10 shows an example of how the first threshold time Tth1 and the second threshold time Tth2 are set. Similar to the first threshold time Tth1, the second threshold time Tth2 is set shorter in steps as the average temperature Save becomes higher.

  Returning to the description of FIG. 9, if an affirmative determination is made in step S34, it is determined that the life of the switching element S * # is near, and the process proceeds to step S36. In step S36, a startup notification instruction process is performed in which a pulse signal including information indicating that the switching element S * # is near the end of life is transmitted to the control device 14. Specifically, this process is a process in which the fail signal FL is the pulse signal. In the present embodiment, the processing in this step constitutes “processing means”.

  FIG. 11 is a time chart illustrating an example of a startup notification instruction process. Specifically, FIG. 11A shows the transition of the counter Cnt, and FIG. 11B shows the transition of the fail signal FL input to the control device 14.

  In the example shown in the figure, the inverter IV is activated by turning on the ignition switch by the user at time t1. Thereafter, a pulse signal including information indicating that the life of the switching element S * # is near is input to the control device 14 at times t1 to t2, which is a startup preparation period of the inverter IV. Here, the pulse signal specifically includes a header for identifying information indicating that the switching element S * # is near in life and a signal including information indicating that the life is near.

  After that, at time t2, the control device 14 that has determined that the pulse signal has been input gives a notification to the host control device that the switching device S * # is near the end of life prior to the start of driving of the switching device S * #. Do it. Thereby, the warning lamp is turned on, and it can be notified to the user that the life of the switching element S * # is near. Incidentally, it is desirable that the notification mode that the lifetime is near is different from the notification mode by the notification instruction process in step S26 of FIG.

  If a negative determination is made in steps S32 and S34, or if the process of step S36 is completed, the series of processes is temporarily terminated.

  According to this embodiment described above, in addition to the effects obtained in the first embodiment, the following effects can be obtained.

  (9) When it is determined that the value of the counter Cnt is equal to or longer than the second threshold time Tth2, a pulse signal including information that the life of the switching element S * # is near is controlled via the second photocoupler 18b. A startup notification instruction process to be transmitted to the device 14 was performed. As a result, the user is informed that the lifetime is near, so that the user can be prompted to replace the inverter IV before the lifetime of the switching element S * # elapses.

  Further, information indicating that the life of the switching element S * # is near is transmitted to the start-up preparation period of the inverter IV, which is a period prior to the start of driving of the switching element S * #. In the start-up preparation period, a configuration in which the logic of the fail signal FL is “L” has not been employed so far in order to transmit another abnormality (for example, overheating abnormality) of the switching element S * # to the control device 14. . In this embodiment, in order to transmit information that the life of the switching element S * # is near in the start-up preparation period, the photocoupler for transmitting the information that the life of the switching element S * # is near, It is also possible to share a photocoupler for transmitting an abnormality. As a result, it is possible to determine from the single fail signal FL that the switching element S * # is near the end of its life and other abnormality of the switching element S * #, and the terminal of the drive IC 20 The number can be reduced.

(Fifth embodiment)
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  In this embodiment, the configuration of the drive IC 20 or the like is changed.

  FIG. 12 shows the configuration of the drive IC 20 according to the present embodiment. In FIG. 12, the same members and the like as those shown in FIG. 2 are given the same reference numerals for the sake of convenience.

  As illustrated, in the present embodiment, the drive IC 20 and the switching element S * # are integrated. In the present embodiment, the integrated member is referred to as a switching module 40. The switching module 40 includes a pair of input / output terminals serving as a flow path for the collector current Ice, an eighth terminal T8 connecting the fifth terminal T5 and the first photocoupler 18a, a sixth terminal T6, and a second photo. A ninth terminal T9 for connecting the coupler 18b, and a tenth terminal T10 for connecting the seventh terminal T7 and the third photocoupler 18c are provided.

  Here, as the reason why the drive IC 20 and the switching element S * # are modularized, for example, the following two can be cited. First, the first reason is to suppress the resonance of the gate voltage when the driving state of the switching element S * # is switched. That is, for example, if the wiring connecting the gate of the switching element S * # and the drive IC 20 is short, the wiring inductance can be reduced, and therefore the resonance of the gate voltage can be suppressed. The second reason is to facilitate various corrections (for example, corrections related to charge / discharge processing) to be performed in the manufacturing process of the switching module 40 due to individual differences of the switching elements S * #.

  Also according to the present embodiment described above, the same effects as those of the first embodiment can be obtained.

(Sixth embodiment)
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the fourth embodiment.

  In the present embodiment, a drive time transmission process for transmitting the drive time of the switching element S * # to the control device 14 is performed immediately after the inverter IV is started.

  FIG. 13 shows the procedure of the drive time transmission process. This process is repeatedly executed by the drive control unit 22 at a predetermined cycle, for example. Since the drive control unit 22 according to the present embodiment is hardware, the process shown in FIG. 13 is actually executed by a logic circuit.

  In this series of processes, when an affirmative determination is made in step S32, the process proceeds to step S38, and the value of the counter Cnt is transmitted to the control device 14 via the second photocoupler 18b.

  If a negative determination is made in step S32 or if the process in step S38 is completed, the series of processes is temporarily terminated.

  Next, a method for transmitting the value of the counter Cnt in step S38 in FIG. 13 will be described with reference to FIG. Here, FIG. 14A to FIG. 14C are transitions of the fail signal FL.

  As shown in the figure, in the present embodiment, during the start-up preparation period of the inverter IV, the value of the counter Cnt is transmitted to the control device 14 by increasing the number of pulses of the fail signal FL as the value of the counter Cnt increases. To do. Here, FIGS. 14A to 14C show pulses when the driving time of the switching element S * # is “1/4”, “2/4”, “3/4” of the lifetime. The method of transmitting the value of the counter Cnt using a number is illustrated. In FIG. 14C, if it is determined that the value of the counter Cnt is equal to or greater than the threshold time Tth after time t2, forcible stop processing or the like is performed.

  Next, the power saving process according to the present embodiment executed by the control device 14 will be described with reference to FIG.

  As shown in the figure, in the present embodiment, as the power saving process, the specified torque Tγ is set to be lower as the number of pulses of the fail signal FL transmitted when the inverter IV is started increases. That is, the greater the number of pulses, the greater the degree of restriction of the torque command value Trq *. FIG. 15 shows an example in which the prescribed torque Tγ is set to be lower stepwise when the number of pulses is “3” or more. In the present embodiment, the power saving process constitutes a “restriction changing unit”.

  According to this embodiment described above, in addition to the effects obtained in the first embodiment, the following effects can be obtained.

  (10) During the start-up preparation period of the inverter IV, the value of the counter Cnt is transmitted to the control device 14 using the number of pulses of the fail signal FL. For this reason, when the inverter IV is replaced, it is possible to grasp the usage frequency of the switching element S * # constituting the inverter IV and the driving time until the end of the life.

  Further, since the value of the counter Cnt is transmitted during the start-up preparation period of the inverter IV, a photocoupler for transmitting the driving time of the switching element S * # and a photocoupler for transmitting other abnormality of the switching element S * # Can be shared. Thereby, the driving time of the switching element S * # and other abnormality of the switching element S * # can be transmitted by a single fail signal FL, and the number of terminals of the drive IC 20 can be reduced. Can be reduced.

  (11) The prescribed torque Tγ is set lower as the number of pulses of the fail signal FL transmitted during the start-up preparation period of the inverter IV increases. For this reason, torque command value Trq * can be limited in a stepwise manner according to the drive time of switching element S * #.

(Seventh embodiment)
Hereinafter, the seventh embodiment will be described with reference to the drawings with a focus on differences from the sixth embodiment.

  In this embodiment, the driving time transmission processing method and the power saving processing method are changed.

  FIG. 16 illustrates a method for transmitting the value of the counter Cnt according to the present embodiment.

  As shown in the figure, in this embodiment, in the start-up preparation period of the inverter IV, the value of the counter Cnt is increased by increasing the duty signal (= TH / Tperiod × 100) of the fail signal FL as the value of the counter Cnt increases. This is transmitted to the control device 14. Here, FIGS. 16A to 16C exemplify a method of transmitting the value of the counter Cnt using the duty when the value of the counter Cnt is “small”, “medium”, and “large”. did. 16A to 16C correspond to the previous FIGS. 14A to 14C.

  Subsequently, the power saving process according to the present embodiment executed by the control device 14 will be described with reference to FIG.

  As shown in the figure, in the present embodiment, as the power saving process, a process of setting the specified torque Tγ lower as the duty of the fail signal FL transmitted during the startup preparation period of the inverter IV is higher. That is, the higher the duty is, the larger the degree of restriction of the torque command value Trq * is. FIG. 17 shows an example in which the prescribed torque Tγ is set continuously low when the Duty is equal to or greater than a predetermined value.

  According to the present embodiment described above, the same effect as that obtained in the sixth embodiment can be obtained.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  The “average voltage calculation means” is not limited to that exemplified in the third embodiment, and may be described below, for example. A voltage that is equal to or higher than the threshold voltage of the switching element S * # (gate voltage at which the collector current starts to flow) and lower than the terminal voltage VH of the constant voltage power supply 28 is defined as a specified voltage. Then, the time average value of the gate voltage Vge is calculated as the average applied voltage Vave when the gate voltage Vge is equal to or higher than the specified voltage under the condition where the ON drive signal is input. In this case, the “time measuring means” is not limited to time measurement of the drive time of the switching element S * # using the ON drive signal, and time measurement is performed using the integrated value of the time when the gate voltage Vge is equal to or higher than the specified voltage as the drive time. You may do.

  The “time measuring means” may be a means for measuring the integrated value of the time during which the current is flowing between the input and output terminals of the switching element S * # as the driving time. Specifically, for example, if the accumulated value of the time when the output value of the sense terminal provided in the switching element S * # and outputting the minute current correlated with the collector current is larger than 0 is counted as the driving time, Good. Note that the output value of the sense terminal is actually detected as the voltage drop amount of the resistor connected to the sense terminal.

  The “diagnostic means” is not limited to that provided in the drive IC 20 of the high voltage system, but may be provided in the control device 14 of the low voltage system. Even in this case, the integrated value of the time during which the ON drive signal is output in the control device 14 can be counted as the drive time. For this reason, for example, the drive time can be measured without providing a configuration for transmitting the gate voltage Vge and the like from the high voltage system side. When the above configuration is adopted, the drive IC 20 and the switching element S * # are provided on different substrates. For this reason, in order to avoid a situation in which the drive time counted in the control device 14 is reset, for example, the time measured in the memory provided in a substrate different from the first substrate 38a is measured. It is desirable to provide a means for backing up the driven time.

  In the first embodiment, the threshold time Tth may be set to a time slightly shorter than the lifetime of the switching element S * #. In this case, before the lifetime of the switching element S * # elapses, the user can be notified that the lifetime is near.

  In the second embodiment, the threshold time Tth may be set only by the average applied voltage Vave.

  The drive IC 20 is not limited to the one shown in FIG. 2 of the first embodiment, and for example, a high voltage system and a low voltage system may be partitioned on the drive IC 20. In this case, the drive IC 20 is provided with the first to third photocouplers 18a to 18c.

  The application target of the present invention is not limited to a vehicle including a rotating machine and an internal combustion engine as an in-vehicle main machine, but may be a vehicle (for example, an electric vehicle) including only a rotating machine as an in-vehicle main machine. In the above vehicle, when the driving of the switching element S * # is stopped as the life of the switching element S * # elapses, the driving power source of the vehicle disappears. For this reason, in a vehicle using only a rotating machine as the in-vehicle main machine, the utility value of the process described in the fourth embodiment that can prompt the user to replace the inverter IV before the life of the switching element S * # elapses is high. .

  The “limit means” is not limited to the power saving process for limiting the collector current Ice described in the second embodiment, and may be, for example, a limit for the gate voltage Vge. Specifically, for example, on the condition that the on-resistance of the switching element S * # does not increase excessively, the gate voltage is set to a voltage (for example, 6 V) that is lower than the terminal voltage VH of the constant voltage power supply 28 and equal to or higher than the threshold voltage. What is necessary is just to restrict | limit Vge. Further, for example, both the collector current Ice and the gate voltage Vge may be limited.

  The method for transmitting the value of the counter Cnt is not limited to the one exemplified in the seventh embodiment. For example, the value of the counter Cnt may be transmitted by lowering the duty of the fail signal FL as the value of the counter Cnt is larger.

  The “restriction changing unit” is not limited to those exemplified in the sixth and seventh embodiments. For example, when it is determined that the value of the counter Cnt has reached the value of the counter Cnt corresponding to the lifetime of the switching element S * #, the driving of the switching element S * # may be prohibited.

  The “restriction changing unit” is not limited to those exemplified in the sixth and seventh embodiments. For example, the limit degree of the gate voltage Vge may be increased as the value of the counter Cnt is increased. Further, for example, the greater the value of the counter Cnt, the greater the degree of restriction of both the collector current Ice and the gate voltage Vge.

  The “temperature detection means” is not limited to the temperature sensitive diode, and may be a thermistor, for example.

  The “insulation transmission means” is not limited to the one provided with the optical insulation element, and may include, for example, a magnetic insulation element (for example, a pulse transformer).

  -"Storage means" is not limited to means capable of holding information without power supply, for example, information provided by power supply on condition that the control system is equipped with a configuration capable of always supplying power to the storage means. A means (for example, a volatile memory) capable of holding the memory may be employed.

  The “switching element” is not limited to the IGBT but may be a MOSFET, for example.

  DESCRIPTION OF SYMBOLS 14 ... Control apparatus, 22 ... Drive control part, 24 ... Memory, S * # ... Switching element.

Claims (8)

Drive signal output means (14) for outputting an on drive signal for turning on the switching element (S * #) or an off drive signal for turning off the switching element (S * #);
Drive means (22) for driving the switching element based on the drive signal output from the drive signal output means;
A first threshold time that is a driving time of the switching element that is assumed to have deteriorated, and the switching element that is shorter than the first threshold time and that defines the first threshold time. Storage means (24) in which a second threshold time defining a degree of deterioration smaller than the degree of deterioration is stored;
Clocking means for clocking the driving time of the switching element;
Diagnosing means for diagnosing that the switching element has deteriorated when it is determined that the drive time measured by the time measuring means is equal to or longer than the first threshold time stored in the storage means;
A notification instructing unit for instructing that the deterioration is made when the diagnosis unit diagnoses that the deterioration has occurred;
Equipped with a,
The diagnostic means further has a function of determining whether or not the driving time measured by the time measuring means is equal to or longer than the second threshold time stored in the storage means,
The drive signal output means and the notification instruction means are provided in a first area,
The driving means, the storage means, the time measuring means, and the diagnostic means are second electrically insulated from the first area and having a reference potential different from the reference potential of the first area. Prepared in the area,
Insulation transmission means (18b) for transmitting a signal from the second region to the first region while electrically insulating between the first region and the second region;
When the diagnosis means determines that the drive time has reached or exceeded the second threshold time, prior to the start of driving the switching element, a pulse signal including information indicating that the life of the switching element is near is transmitted to the insulation transmission Processing means for performing processing to be transmitted to the notification instruction means via means;
With
The switching element driving device , wherein the notification instruction means further issues a notification instruction that the lifetime is near, on condition that the pulse signal is input .   2. The switching device drive device according to claim 1, wherein the time measuring means measures the integrated value of the time during which the ON drive signal is output from the drive signal output means as the drive time. Temperature detecting means (SD * #, 36) for detecting the temperature of the switching element;
Based on the temperature detected by the temperature detecting means and the driving time measured by the time measuring means, an average temperature calculating means for calculating an average temperature of the switching element in the driving time;
Threshold time setting means for setting the first threshold time to be shorter as the average temperature calculated by the average temperature calculation means is higher;
The switching element drive device according to claim 1, further comprising: Voltage detection means for detecting an applied voltage of the switching control terminal of the switching element under a situation in which the ON drive signal is output from the drive signal output means;
Based on the applied voltage detected by the voltage detecting means and the driving time measured by the time measuring means, an average voltage calculating means for calculating an average applied voltage of the switching control terminal at the driving time;
Threshold time setting means for setting the first threshold time to be shorter as the average applied voltage calculated by the average voltage calculation means is higher;
The switching element drive device according to claim 1, further comprising: The driving means, the storage means, the timing means and the diagnostic means are provided in a single integrated circuit (20),
The driving device for a switching element according to any one of claims 1 to 4, wherein the integrated circuit and the switching element are provided on a common substrate (38b). The driving means, the storage means, the timing means and the diagnostic means are provided in a single integrated circuit (20),
The driving device for a switching element according to claim 1, wherein the integrated circuit and the switching element are integrated. When it is diagnosed that are degraded by the diagnostic means, the switching device according to any one of claims 1 to 6, further comprising a forcibly stopping means for stopping the driving of the switching element Drive device. When it is diagnosed that the diagnosis unit has deteriorated, it further comprises a limiting unit that limits at least one of a current flowing between the input / output terminals of the switching element and an applied voltage of the switching control terminal of the switching element. drive of the switching element according to any one of claims 1 to 6, wherein.

Images