JP2019097011A - Signal propagation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal propagation device capable of suppressing power consumption of an insulating element in a signal propagation device for transmitting from one of a high-voltage system and a low-voltage system of a motor generator control system to the other. Signal propagation of a binary switching signal (c #) from one system of a high voltage system (Shy) or a low voltage system (Syl) to the other system via an insulating element (34). The apparatus includes a switching signal generation unit (70) that generates a first logic signal for driving the insulating element or a second logic signal for stopping the driving of the insulating element as the switching signal. When the switching signal generation unit propagates the first information to the other system, it generates a first logic signal or a second logic signal, and propagates a second information different from the first information to the other system. In this case, a signal having a specified period consisting of a first logic signal and a second logic signal is generated. [Selection diagram] Fig. 2

Description

  The present invention relates to a signal propagation device for transmitting binary propagation target signals of logic "H" and logic "L" from one of high voltage system and low voltage system to another via an isolation element.

  For example, as shown in Patent Document 1 below, as a signal propagation device of this type, a drive signal of a switching element of an inverter connected to a motor in an on-vehicle hybrid system can be transmitted from a low voltage system to a high voltage system via a photocoupler. There is something to convey. That is, the drive signal of the switching element of the inverter is generated by the low voltage system, and the photocoupler is used to output the drive signal to the high voltage system, thereby achieving insulation between the low voltage system and the high voltage system.

JP, 2009-60751, A

  By the way, it is known that the power consumption of the photocoupler depends on the value of the current flowing to the primary side (photodiode side). Here, with regard to the current flowing through the photodiode, the power consumption of the photocoupler increases as the period for which the current flows in the photodiode is longer.

  On the other hand, the period in which current flows to the photodiode is a period of logic "H" or logic "L" of a propagation target signal such as a drive signal. Hereinafter, a period in which current flows to the photodiode is referred to as a period of logic “H”. Therefore, the period in which the current flows to the photodiode is determined according to the period of the logic "H" of the propagation target signal.

  As a propagation target signal, when an abnormality occurs in either one of the high pressure system and the low pressure system, an abnormality propagation signal used to propagate the information to the other is known. In the abnormal propagation signal, the abnormal propagation signal is maintained at logic "H" during the period for propagating the information indicating that the abnormality has not occurred in order to propagate the information of the abnormality occurrence early and surely. During propagation of information on the occurrence of an abnormality, the abnormality propagation signal is often configured to switch to the logic "L". For this reason, current is continuously supplied to the photodiode in a period during which information indicating that no abnormality has occurred is transmitted, and power consumption of the photocoupler is increased.

  Such a problem is not limited to the abnormal propagation signal, but is a common problem to the propagation target signal maintained at the logic “H” in the period for propagating the specific information. In addition, such a problem is not limited to the photocoupler, and is a common problem in general to insulating elements such as magnetic couplers. In the insulating element, the power consumption of the insulating element increases as the driving period of the insulating element is longer.

  The present invention has been made to solve the above-mentioned problems, and its object is to provide a binary "high" and "low" voltage signal to be propagated through an isolation element between logic "H" and logic "L". It is an object of the present invention to provide a signal propagation device capable of suppressing the power consumption of an isolation element in a signal propagation device for transmitting from either one to the other.

  The present invention relates to a signal propagation device for propagating binary switching signals of logic “H” and logic “L” from either one of a high voltage system and a low voltage system to another system via an isolation element, A second logic signal provided in the one system and having a logic different from the first logic signal for driving the insulating element or the first logic signal for stopping driving the insulating element is generated as the switching signal. A switching signal generation unit is provided, and the switching signal generation unit generates the first logic signal or the second logic signal as the switching signal when propagating the first information to the other system, and When the second information different from the information of 1 is propagated to the other system, a signal having a defined cycle consisting of the first logic signal and the second logic signal is generated as the switching signal. That.

  According to the present invention, the period during which the second information is propagated to the other system includes the period during which the switching signal becomes the second logic signal. Therefore, the period in which the insulating element is in the driving state can be shortened as compared with the configuration in which the switching signal is maintained as the first logic signal in the period in which the second information is propagated to the other system. Thus, power consumption due to the drive of the insulating element can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS The whole block diagram of the control system of the motor generator which concerns on 1st Embodiment. The figure which shows the interface which concerns on 1st Embodiment. The time chart which shows the signal propagation mode concerning a 1st embodiment. The figure which shows the interface which concerns on 2nd Embodiment. The time chart which shows the signal propagation mode concerning a 3rd embodiment. The time chart which shows the signal propagation mode concerning a 4th embodiment. The time chart which shows the signal propagation mode concerning a 5th embodiment. The time chart which shows the signal propagation mode concerning a 6th embodiment. The figure which shows the interface which concerns on 7th Embodiment. The time chart which shows the signal propagation mode concerning a 7th embodiment. The figure which shows the interface which concerns on 8th Embodiment. The time chart which shows the signal propagation aspect which concerns on 8th Embodiment. The figure which shows the interface which concerns on other embodiment.

First Embodiment
Hereinafter, a first embodiment in which a signal propagation device according to the present invention is applied to a hybrid vehicle will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of a motor generator control system 100 according to the present embodiment. Control system 100 includes an inverter 12, an interface 16, and a microcomputer 20. In the present embodiment, the control system 100 corresponds to a “signal propagation device”.

  As illustrated, an inverter 12 is connected to three phases (U phase, V phase, W phase) of the motor generator 10. The inverter 12 is a three-phase inverter, and appropriately applies the voltage of the high voltage battery 14 to the three phases of the motor generator 10. Specifically, in order to electrically connect each of the three phases to the positive electrode side or the negative electrode side of high-voltage battery 14, inverter 12 selects switching elements Sup and Sun, switching elements Svp and Svn, and switching elements Swp and Swn. It is configured with a parallel connection. A connection point at which the switching element Sup and the switching element Sun are connected in series is connected to the U phase of the motor generator 10. Further, a connection point at which switching element Svp and switching element Svn are connected in series is connected to the V phase of motor generator 10. Furthermore, a connection point at which the switching element Swp and the switching element Swn are connected in series is connected to the W phase of the motor generator 10.

  In addition, as the high voltage battery 14, for example, a lithium ion storage battery or a nickel hydrogen storage battery can be used. Further, as the motor generator 10, a synchronous machine (permanent magnet synchronous machine) is used. In addition, voltage-controlled semiconductor switching elements are used as switching elements S # (# = up, un, vp, vn, wp, wn), and more specifically, an insulated gate bipolar transistor (IGBT) is used. . The inverter 12 also includes a flywheel diode D # connected in anti-parallel to each switching element S #.

  The switching element S # is driven by the microcomputer 20 having the low voltage battery 18 as a power source through the interface 16. The definition signal generation circuit 22 of the microcomputer 20 generates a definition signal r # that defines a drive signal g # for driving the switching element S #, and outputs the generated definition signal r # to the interface 16. The interface 16 generates a drive signal g # from the definition signal r # and outputs the drive signal g # to the drive circuit DU corresponding to each switching element S #. In the present embodiment, the state in which the switching element S # is driven corresponds to the state in which one system is driven, and the state in which the switching element S # is not driven is “stopping the driving of one system”. It corresponds to the state.

  FIG. 2 shows a circuit diagram of the interface 16. The interface 16 actually includes the circuits shown in FIG. 2 separately for each of the definition signals r #, but only one of them is shown here.

  As illustrated, the interface 16 isolates the high voltage system Syh configured to include the inverter 12 and the first and second photocouplers 30 and 34 that insulate the low voltage system Syl configured to include the microcomputer 20. Is equipped. In the present embodiment, the high pressure system Syh corresponds to "one system", and the low pressure system Syl corresponds to "the other system".

  The low voltage system Syl includes a low voltage system side power supply 40, a first resistor 42, and a first drive switching element 44. In the low voltage system Syl, it is connected to the ground of the low voltage system Syl via a series circuit in which the first resistor 42, the first photodiode 32 of the first photocoupler 30, and the first drive switching element 44 are connected in this order. ing. A regulation signal r # is input to the gate of the first drive switching element 44, and the on / off state is switched by the regulation signal r #.

  Specifically, when the first drive switching element 44 is turned on, a current flows from the low voltage system side power supply 40 to the ground of the low voltage system Syl via the first photodiode 32. Turns on. In addition, when the first drive switching element 44 is turned off, the current does not flow from the low voltage system power supply 40 to the ground of the low voltage system Syl via the first photodiode 32, so the first photocoupler 30 is turned off. It becomes a state. That is, the first photocoupler 30 is turned on when the definition signal r # becomes logic "H", and the first photocoupler 30 is turned off when the definition signal r # becomes logic "L".

  The high voltage system Syh includes a high voltage system power supply 50 and a second resistor 52. In the high voltage system Syh, the high voltage system power supply 50 is connected to the ground of the high voltage system Syh via the second resistor 52 and the first phototransistor 33 of the first photocoupler 30. Since the high voltage system power supply 50 is grounded via the second resistor 52 and the first phototransistor 33 when the first photocoupler 30 is turned on by the regulation signal r # becoming logic “H”, The drive signal g # of logic "L" is input from the photocoupler 30 to the drive circuit DU. Further, when the first photocoupler 30 is turned off by the regulation signal r # becoming logic "L", the high voltage system power supply 50 is not grounded, so that the logic "H" is transmitted from the first photocoupler 30 to the drive circuit DU. Drive signal g # is input. Therefore, the drive signal g # is synchronized with the definition signal r # and has a logic value opposite to that of the definition signal r #. The second photocoupler 34 will be described later.

  The drive signal acquisition circuit 74 of the drive circuit DU acquires the drive signal g #. The drive circuit DU is connected to the gate of the corresponding switching element S #, and outputs a control signal j # that switches between the on state and the off state of the switching element S # based on the drive signal g #. Specifically, when the drive signal g # is logic "H", the control signal j # for turning on the switching element S # is output, and when the drive signal g # is logic "L", A control signal j # for turning off the switching element S # is output. When the drive circuit DU determines that no abnormality occurs in the switching element S #, the drive circuit DU sets the abnormality determination signal f # to logic “L”. On the other hand, when the drive circuit DU determines that the switching element S # is in the abnormal state, the drive circuit DU sets the abnormality determination signal f # to the logic “H”. Here, the abnormality of the switching element S # includes, for example, at least one of an overcurrent abnormality where a current flowing through the switching element S # exceeds an overcurrent threshold and an overheat abnormality where a temperature of the switching element S # exceeds an overheat threshold. Is included. In the present embodiment, the drive signal acquisition circuit 74 corresponds to a “drive signal acquisition unit”.

  Switch signal generation circuit 70 of drive circuit DU generates switch signal c # that defines propagation signal x # for detecting an abnormality of switching element S #, based on drive signal g # and abnormality determination signal f #. , Output to the interface 16. The interface 16 generates the propagation signal x # from the switching signal c #. In the present embodiment, the switching signal generation circuit 70 corresponds to a “switching signal generation unit”.

  When the switching signal generation circuit 70 determines that the logic of the abnormality determination signal f # is “L”, as shown in FIG. 3, the switching signal c # having the same logical value as the logical value of the drive signal g # Generate Therefore, the logical value of the switching signal c # in the period in which the drive signal g # is in the logic "L" becomes "L", and the logical value of the switching signal c # in the period in which the drive signal g # is in the logic "H" is It becomes "H". On the other hand, when the switching signal generation circuit 70 determines that the logic of the abnormality determination signal f # is “H”, the switching signal generation circuit 70 generates a signal of logic “L” as the switching signal c #.

  In the interface 16, the second photocoupler 34 is used to propagate the switching signal c # from the high voltage system Syh to the low voltage system Syl. The high voltage system Syh further includes a third resistor 54 and a second drive switching element 56. In the high voltage system Syh, the high voltage system side power supply 50 is a high voltage system via a series circuit in which the third resistor 54, the second photodiode 36 of the second photocoupler 34, and the second drive switching element 56 are connected in this order. It is connected to the ground of Syh. The switching signal c # is input to the gate of the second drive switching element 56, and the second drive switching element 56 is turned on (conductive) and off (cut off) by the switch signal c #. Switching) is made.

  Specifically, when the second drive switching element 56 is turned on, a current flows from the high voltage system power supply 50 to the ground of the high voltage system Syh via the second photodiode 36. The second phototransistor 37 is turned on. When the second drive switching element 56 is turned off, no current flows from the high voltage system power supply 50 to the ground of the high voltage system Syh via the second phototransistor 37, so the second photocoupler 34 is turned off. It becomes a state. That is, when the switching signal c # becomes logic "H", the second photocoupler 34 is turned on, and when the switching signal c # becomes logic "L", the second photocoupler 34 is turned off. That is, the switching signal c # can be said to be a signal that switches between the on state (driving state) for driving the second photocoupler 34 and the off state (stopping state) for stopping the driving of the second photocoupler 34. .

  The low voltage system Syl further includes a fourth resistor 46 and an exclusive OR circuit 48. In the low voltage system Syl, the low voltage system power supply 40 is connected to the ground of the low voltage system Syl via the fourth resistor 46 and the second phototransistor 37 of the second photocoupler 34. When the second photocoupler 34 is turned on by the switching signal c # becoming logic "H", the low voltage system power supply 40 is grounded via the fourth resistor 46 and the second phototransistor 37. Therefore, the propagation signal x # of logic "L" is input from the second photocoupler 34 to the first input terminal 48a of the exclusive OR circuit 48. In addition, when the second photocoupler 34 is turned off by the switching signal c # becoming logic "L", the low voltage system power supply 40 is not grounded. Therefore, the propagation signal x # of logic "H" is input from the second photocoupler 34 to the first input terminal 48a of the exclusive OR circuit 48. Therefore, the propagation signal x # is synchronized with the switching signal c # and has a logic value opposite to that of the switching signal c #.

  The second input terminal 48b of the exclusive OR circuit 48 is connected to the gate of the first drive switching element 44, and receives the definition signal r #. Therefore, exclusive OR circuit 48 attains a logic “H” when the logical value of prescribed signal r # and the logical value of propagation signal x # are different, and the logical value of prescribed signal r # and propagation signal x # When the logic value is equal, a detection signal z # that is logic "L" is output from the output terminal 48c to the microcomputer 20. In the present embodiment, the exclusive OR circuit 48 corresponds to a “detection signal generation unit”.

  FIG. 3 shows a signal propagation mode in which the switching signal c # is propagated by the control system 100. More specifically, FIG. 3 (a) shows the transition of the regulation signal r #, FIG. 3 (b) shows the transition of the drive signal g #, and FIG. 3 (c) shows the transition of the abnormality determination signal f #. FIG. 3 (d) shows the transition of the switching signal c #, FIG. 3 (e) shows the transition of the propagation signal x #, and FIG. 3 (f) shows the transition of the detection signal z #.

  The switching signal c # is a binary signal of logic “H” and logic “L”, and is propagated through the second photocoupler 34 from the high voltage system Syh to the low voltage system Syl. The switching signal c # is generated based on the drive signal g #, that is, the regulation signal r #. In the present embodiment, the switching signal c # corresponds to a “propagation target signal”, and the second photocoupler 34 corresponds to an “insulation element”. Also, the switching signal c # of logic "H" corresponds to the "first logic signal", and the switching signal c # of logic "L" corresponds to the "second logic signal".

  The definition signal r # is a signal consisting of two values of logic “H” and logic “L”, and switches between logic “H” and logic “L” at a predetermined predetermined cycle Tn. Hereinafter, a period in which the regulation signal r # is logic “L” is referred to as an on-command period Ta for instructing the switching element S # to turn on, and a period in which the regulation signal r # is logic “H” is referred to as the switching device S #. The off command period Tb for instructing the off of the In the illustrated example, the logic "L" is obtained at time t1, and the logic "H" is obtained at time t2 when the on-command period Ta has elapsed from time t1. Also, at time t3 when the off command period Tb has elapsed from time t2, the logic becomes "L". In the present embodiment, the definition signal r # corresponds to a “period signal”, and the definition signal generation circuit 22 corresponds to a “period signal acquisition unit”. Further, the definition signal r # of the logic “L” corresponds to the “fifth logic signal”, and the definition signal r # of the logic “H” corresponds to the “sixth logic signal”.

  When switching element S # is normal, switching signal c # is in synchronization with definition signal r # and has a logic value opposite to that of definition signal r #, that is, the same logic value as that of drive signal g #. The signal has Therefore, in the on-command period Ta, the drive signal g # becomes logic "H" and the switching signal c # becomes logic "H". On the other hand, in the off command period Tb, the drive signal g # becomes logic "L", and the switching signal c # becomes logic "L". In the present embodiment, the drive signal g # of logic “H” corresponds to the “third logic signal”, and the drive signal g # of logic “L” corresponds to the “fourth logic signal”.

  On the other hand, when an abnormality occurs in the switching element S #, the switching signal c # always becomes logic "L". In the illustrated example, an abnormality occurs in the switching element S # at time t4, the logic of the abnormality determination signal f # is switched to "H", and the switching signal c # is switched to the logic "L". As a result, the detection signal z # becomes logic "L" during a period from time t4 to time t5 when the definition signal r # switches to logic "H" thereafter. If the microcomputer 20 determines that the detection signal z # has become a logic "L", it determines that an abnormality has occurred in the switching element S #. When the microcomputer 20 determines that an abnormality occurs in the switching element S #, the microcomputer 20 performs a fail-safe process such as stopping the generation and output of the definition signal r #, for example.

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

  The switching signal c # includes the off command period Tb in a period in which the switching element S # is normal, and the second photocoupler 34 is turned off in the off command period Tb. Therefore, a period during which the second photocoupler 34 is in the on state is compared with a configuration in which the second photocoupler 34 is maintained in the on state without the off command period Tb being included in the period when the switching element S # is normal. It can be shortened. Accordingly, it is possible to suppress the power consumption due to the second photocoupler 34 being turned on, specifically, the power consumption due to the current flowing to the second photodiode 36.

  In the present embodiment, the switching signal c # is synchronized with the drive signal g # in a period in which the switching element S # is normal. Therefore, the configuration of switching signal generation circuit 70 can be simplified as compared to the case where switching signal c # and drive signal g # are not synchronized.

  Particularly, in the present embodiment, it is detected that the switching element S # has an abnormality by utilizing the synchronization between the switching signal c # and the drive signal g # in a period in which the switching element S # is normal. Do. Specifically, using the exclusive OR circuit 48, that the switching signal c # and the drive signal g # are not synchronized, that is, the logic value of the definition signal r # and the logic value of the propagation signal x # are It detects that it became a different logic value. Therefore, as compared with the configuration in which the switching signal c # and the drive signal g # are not synchronized, the occurrence of an abnormality in the switching element S # can be easily detected.

  In the present embodiment, the switching signal c # is logic “H” in the on command period Ta. Generally, the abnormality occurring in the switching element S # occurs in the drive period of the drive circuit DU where the drive signal g # is at the logic "H", that is, in the on-command period Ta. Therefore, the switching signal c # becomes logic "H" in the on command period Ta, and the abnormality occurs in the on command period Ta compared to the configuration in which the switching signal c # becomes logic "H" in the off command period Tb. Can be transmitted early.

Second Embodiment
The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment.

  The present embodiment is different from the first embodiment in that the interface 16 does not include the exclusive OR circuit 48 as shown in FIG. That is, the interface 16 outputs the propagation signal x # to the microcomputer 20. FIG. 4 is a circuit diagram of the interface 16 according to the present embodiment. In FIG. 4, the same members as the members shown in FIG. 2 are given the same reference numerals for convenience, and the description thereof is omitted.

  In the present embodiment, the microcomputer 20 can detect that an abnormality has occurred in the switching element S # when it determines that the period in which the propagation signal x # is the logic “L” has exceeded the specified cycle Tn.

  According to this embodiment described above, the same effect as that of the first embodiment can be obtained. Further, since the interface 16 does not include the exclusive OR circuit 48, the configuration of the interface 16 can be simplified.

Third Embodiment
The third embodiment will be described below with reference to the drawings, focusing on the differences with the second embodiment. In the present embodiment, the switching signal c # is different from that of the second embodiment described above.

  The switching signal c # of this embodiment will be described with reference to FIG. Specifically, FIG. 5 (a) shows the transition of the regulation signal r #, FIG. 5 (b) shows the transition of the drive signal g #, and FIG. 5 (c) shows the transition of the abnormality determination signal f #. FIG. 5 (d) shows the transition of the switching signal c #, and FIG. 5 (e) shows the transition of the propagation signal x #.

  In this embodiment, when the switching element S # is normal, the switching signal c # becomes logic “H” in a part of the off command period Tb, and the other period, that is, the other period of the off command period Tb. And in the on command period Ta, it becomes logic "L". The timing when the switching signal c # becomes logic “H” is equal to the start timing of the off command period Tb, that is, the timing when the drive signal g # becomes logic “L”. Further, the period Tk in which the switching signal c # is at the logic "H" is shorter than the off command period Tb. On the other hand, when an abnormality occurs in the switching element S #, the switching signal c # always becomes logic "L".

  The microcomputer 20 can detect that an abnormality has occurred in the switching element S # when it determines that the period in which the propagation signal x # becomes logic “H” exceeds the prescribed cycle Tn. Specifically, as shown by broken lines in (d) and (e) in FIG. 5, the microcomputer 20 determines that the propagation signal x # is logic “L” at the start timing of the off command period Tb determined by the definition signal r #. By detecting the failure, it is possible to detect that an abnormality has occurred in switching element S #.

  According to the embodiment described above, the switching signal c # is not synchronized with the drive signal g # in a period in which the switching element S # is normal. Therefore, it is not necessary to maintain switching signal c # at logic "H" over on command period Ta or off command period Tb as in the case where switching signal c # and drive signal g # are synchronized. . Therefore, a period in which the switching signal c # is set to logic "H" can be set as a part of the on command period Ta or the off command period Tb. As a result, compared with the case where the switching signal c # and the drive signal g # are synchronized, the period in which the second photocoupler 34 is in the on state can be shortened while the switching element S # is normal. Power consumption in the second photocoupler 34 can be suitably suppressed.

  In particular, in the present embodiment, the switching signal c # is switched to the logic “H” at the start timing of the off command period Tb. Therefore, as compared with the case where the switching signal c # is switched to the logic "H" late from the start timing of the off command period Tb, the abnormality occurring in the on command period Ta can be propagated earlier.

Fourth Embodiment
The fourth embodiment will be described below with reference to the drawings, focusing on the differences from the second embodiment. In the present embodiment, the switching signal c # is different from that of the second embodiment described above.

  The switching signal c # of this embodiment will be described with reference to FIG. Specifically, FIG. 6 (a) shows the transition of the regulation signal r #, FIG. 6 (b) shows the transition of the drive signal g #, and FIG. 6 (c) shows the transition of the abnormality determination signal f #. FIG. 6 (d) shows the transition of the switching signal c #, and FIG. 6 (e) shows the transition of the propagation signal x #.

  In the present embodiment, when the switching element S # is normal, the switching signal c # is logic “L” in the on command period Ta, and is logic “H” in the off command period Tb. Therefore, in the on-command period Ta, the drive signal g # becomes logic "H" and the switching signal c # becomes logic "L". On the other hand, in the off command period Tb, the drive signal g # becomes logic "L" and the switching signal c # becomes logic "H". On the other hand, when an abnormality occurs in the switching element S #, the switching signal c # always becomes logic "H".

  If the microcomputer 20 determines that the period from when the propagation signal x # switches to logic “H” to next switching to logic “H” is shorter than the prescribed period Tn, or the propagation signal x # is logic “ If it is determined that the period of “H” exceeds the specified cycle Tn, it is possible to detect that an abnormality has occurred in the switching element S #. Specifically, as shown by broken lines in (d) and (e) of FIG. 6, the microcomputer 20 determines that the propagation signal x # becomes logic “L” in the on-command period Ta determined by the definition signal r #. By detecting, it is possible to detect that an abnormality has occurred in switching element S #.

  According to the embodiment described above, the switching signal c # is synchronized with the drive signal g # and has a logic value opposite to that of the drive signal g # in a period in which the switching element S # is normal. Become. Therefore, switching signal c # can be easily generated from drive signal g # using a logical NOT circuit or the like, and the configuration of switching signal generation circuit 70 can be simplified.

  In the present embodiment, when an abnormality occurs in the switching element S #, the switching signal c # is maintained at “H”. As a result, when an abnormality occurs in the switching element S #, the second photocoupler 34 can be maintained in the on state. Therefore, as compared with the configuration in which the second photocoupler 34 is maintained in the OFF state, the abnormality of the switching element S # generated in the on-command period Ta can be propagated earlier.

Fifth Embodiment
The fifth embodiment will be described below with reference to the drawings, focusing on the differences with the second embodiment. In the present embodiment, the regulation signal r # and the switching signal c # are different from those of the second embodiment described above.

  The definition signal r # and the switching signal c # of this embodiment will be described with reference to FIG. More specifically, FIG. 7 (a) shows the transition of the regulation signal r #, FIG. 7 (b) shows the transition of the drive signal g #, and FIG. 7 (c) shows the transition of the abnormality determination signal f #. FIG. 7 (d) shows the transition of the switching signal c #, and FIG. 7 (e) shows the transition of the propagation signal x #.

  In the illustrated example, the definition signal r # includes a plurality of on command periods Ta having different lengths. In the illustrated example, the first to third on-command periods Ta1 to Ta3 having different lengths are included in the period up to the time t10 when the switching element S # is normal. The lengths of the first on command period Ta3, the second on command period Ta4, and the third on command period Ta5 become shorter in this order. In the illustrated example, the length of the off command period Tb is constant.

  Further, in the present embodiment, when the switching element S # is normal, the switching signal c # switches between logic “H” and logic “L” every predetermined prescribed cycle Tc. The specified cycle Tc is set shorter than the third on command period Ta3 which is the shortest of the first to third on command periods Ta1 to Ta3. Thus, the first to third on-command periods Ta1 to Ta3 include at least one period in which the switching signal c # is at the logic "H". On the other hand, when an abnormality occurs in the switching element S #, the switching signal c # always becomes logic "H".

  As shown by the broken lines in FIGS. 7D and 7E, the microcomputer 20 determines that the switching element S # is abnormal when it determines that the period in which the propagation signal x # becomes logic “H” exceeds the specified period Tc. Can be detected.

  According to the present embodiment described above, the specified cycle Tc of the switching signal c # is set shorter than the shortest period of the on-command period Ta. Therefore, the on-command period Ta can include at least one period in which the switching signal c # is logic "H", and the abnormality of the switching element S # generated in the on-command period Ta can be propagated early. it can.

  In the present embodiment, since the switching signal c # switches between logic “H” and logic “L” at a prescribed cycle Tc, the switching signal c # also becomes logic “H” in the off command period Tb. Therefore, not only the abnormality of the switching element S # generated in the on-command period Ta, but also the abnormality of the switching element S # generated in the off-command period Tb can be propagated early.

Sixth Embodiment
The sixth embodiment will be described below with reference to the drawings, focusing on the differences from the second embodiment. In the present embodiment, the switching signal c # is different from that of the second embodiment described above.

  The switching signal c # of this embodiment will be described with reference to FIG. Specifically, FIG. 8 (a) shows the transition of the regulation signal r #, FIG. 8 (b) shows the transition of the drive signal g #, and FIG. 8 (c) shows the transition of the abnormality determination signal f #. FIG. 8 (d) shows the transition of the switching signal c #, and FIG. 8 (e) shows the transition of the propagation signal x #.

  In the present embodiment, when the switching element S # is normal, the switching signal c # becomes logic “H” at the start timing and end timing of the on command period Ta, and becomes logic “L” in the other periods. The period Td in which the switching signal c # is logic "H" is shorter than the on command period Ta and the off command period Tb. On the other hand, when an abnormality occurs in the switching element S #, the switching signal c # always becomes logic "L".

  The microcomputer 20 can detect that an abnormality has occurred in the switching element S # when it determines that the period in which the propagation signal x # becomes logic “H” exceeds the prescribed cycle Tn. Specifically, as shown by broken lines in (d) and (e) of FIG. 8, the microcomputer 20 determines that the propagation signal x # is logic “L” at the end timing of the on command period Ta determined by the definition signal r #. By detecting the failure, it is possible to detect that an abnormality has occurred in switching element S #.

  According to the present embodiment described above, the switching signal c # has a logic "H" at the start timing and end timing of the on command period Ta, that is, at the start timing of the on command period Ta and the start timing of the off command period Tb. It becomes. Therefore, in both the on command period Ta and the off command period Tb, the occurrence of an abnormality in the switching element S # can be propagated, and the occurrence of an abnormality in the switching element S # can be propagated early. it can.

Seventh Embodiment
The seventh embodiment will be described below with reference to the drawings, focusing on the differences with the second embodiment. In the present embodiment, the circuit configuration of the interface 16 and the switching signal c # are different compared to the second embodiment described above.

  As shown in FIG. 9, the high voltage system Syh further includes an inductor element 58, a free wheeling diode 60, and a smoothing capacitor 62.

  The inductor element 58 is connected between the third resistor 54 and the second photodiode 36 of the second photocoupler 34, and the third resistor 54, the inductor element 58, the second photodiode 36, and the second drive. The high-voltage system side power supply 50 is connected to the ground of the high-voltage system Syh via a series circuit connected in order of the switching elements 56. In the present embodiment, the voltage of the ground of the high voltage system Syh corresponds to the “reference voltage”.

  In the series circuit, a diode 60 for return current is connected in reverse parallel to the inductor element 58 and the second photodiode 36. When the second drive switching element 56 is turned on by the switching signal c #, a current flows through the inductor element 58, and magnetic energy is accumulated in the inductor element 58. Thereafter, when the second drive switching element 56 is switched from the on state to the off state by the switching signal c #, an electromotive force is generated in the inductor element 58. Thereby, the return current i # flows in the closed circuit including the inductor element 58, the second photodiode 36, and the return diode 60. As a result, even after the second drive switching element 56 is switched to the off state, the second photocoupler 34 has a constant period Tf (see FIG. 10) in which the return current i # larger than the predetermined threshold current ik flows. It is maintained in the on state throughout. The current value of the threshold current ik is determined by the second photocoupler 34.

  A smoothing capacitor 62 is connected in parallel to the inductor element 58 and the second photodiode 36. That is, an antiparallel circuit 66 including the element group of the inductor element 58 and the second photodiode 36, the free wheeling diode 60, and the smoothing capacitor 62 is configured.

  The switching signal c # of this embodiment will be described with reference to FIG. Specifically, FIG. 10 (a) shows the transition of the definition signal r #, FIG. 10 (b) shows the transition of the drive signal g #, and FIG. 10 (c) shows the transition of the abnormality determination signal f #. 10 (d) shows the transition of the switching signal c #, FIG. 10 (e) shows the transition of the return current i #, and FIG. 10 (f) shows the transition of the propagation signal x #.

  In the present embodiment, when the switching element S # is normal, the switching signal c # switches between the logic “H” and the logic “L” every predetermined prescribed period Te. In the switching signal c #, the length of the period of logic “H” and the length of the period of logic “L” are equal to each other, and are both Te / 2.

  In the present embodiment, the defined period Te is set such that the length Te / 2 of the period of the logic "L" in the switching signal c # is shorter than the fixed period Tf. Therefore, in a period in which the switching element S # is normal, the return current i # is always larger than the threshold current ik, and the second photocoupler 34 is maintained in the on state. As a result, in the period in which the switching element S # is normal, the propagation signal x # is always at the logic "L".

  On the other hand, when an abnormality occurs in the switching element S #, the switching signal c # always becomes logic "L". The return current i # decreases to the threshold current ik at time t14 when a predetermined period Tf has elapsed from the timing when the switching signal c # is last switched to the logic "L" in a period in which the switching element S # is normal. Causes the propagation signal x # to switch to logic "H". Therefore, the time t14 when the propagation signal x # switches to the logic "H" is delayed by the delay time Tg from the time t4 when the abnormality occurs in the switching element S #.

  The microcomputer 20 can detect that an abnormality has occurred in the switching element S # by detecting that the propagation signal x # has been switched to the logic “H”.

  According to the present embodiment described above, the inductor element 58 and the diode 60 for return current are provided. Therefore, even during a period in which the switching signal c # becomes logic "L" and current does not flow from the high voltage system power supply 50 to the second photodiode 36 of the second photocoupler 34, a return current flows in the second photodiode 36. And the second photocoupler 34 can be turned on. Thereby, while suppressing the power consumption in the second photocoupler 34, it is possible to extend the period for propagating whether or not an abnormality has occurred in the switching element S #.

  In particular, in the present embodiment, the defined period Te is set such that the length Te / 2 of the period of the logic “L” in the switching signal c # is shorter than the fixed period Tf. Therefore, in a period in which the switching element S # is normal, the second photocoupler 34 can always be in the on state. Thus, it can be constantly propagated whether or not an abnormality has occurred in switching element S #.

Eighth Embodiment
The eighth embodiment will be described below with reference to the drawings, focusing on the differences from the seventh embodiment. The present embodiment differs from the seventh embodiment in the circuit configuration on the high voltage system Syh side.

  As shown in FIG. 11, the high voltage system Syh includes a discharge switching element 64. The discharge switching element 64 is connected between the anti-parallel circuit 66 and the ground of the high voltage system Syh. Discharge signal generation circuit 72 of drive circuit DU generates discharge signal h # for discharging the charge of anti-parallel circuit 66, and outputs the generated signal to interface 16. The discharge signal h # is input to the gate of the discharge switching element 64, and the on / off state is switched by the discharge signal h #. In the present embodiment, the discharge signal generation circuit 72 corresponds to a “discharge signal generation unit”.

  The discharge signal h # of the present embodiment will be described with reference to FIG. Specifically, FIG. 12 (a) shows the transition of the definition signal r #, FIG. 12 (b) shows the transition of the drive signal g #, and FIG. 12 (c) shows the transition of the abnormality determination signal f #. 12 (d) shows the transition of the switching signal c #, FIG. 12 (e) shows the transition of the return current i #, and FIG. 12 (f) shows the transition of the discharge signal h #, FIG. 12 (g) shows the transition of the propagation signal x #.

  Discharge signal h # is a signal consisting of two values of logic "H" and logic "L", and becomes logic "L" when switching element S # is normal, and an abnormality occurs in switching element S #. To the logic "H". When discharge signal h # is at logic "L", discharge switching element 64 is turned off. In this case, the charge of the anti-parallel circuit 66 is not discharged to the ground of the high voltage system Syh. Therefore, as described above, the second photocoupler 34 is maintained in the on state during the period in which the switching element S # is normal.

  On the other hand, when the discharge signal h # is logic "H", the discharge switching element 64 is turned on. In this case, the charge of the anti-parallel circuit 66 is discharged to the ground of the high voltage system Syh. Therefore, even within the fixed period Tf after the switching signal c # is switched to the logic “L”, the flow of the return current i # is suppressed, and the second photocoupler 34 is turned off. As a result, propagation signal x # is switched to logic "L".

  According to the present embodiment described above, the discharge switching element 64 and the discharge signal generation circuit 72 are provided. Therefore, when an abnormality occurs in switching element S #, propagation signal x # can be switched to logic "L" by switching discharge signal h #. Therefore, as in the configuration of the seventh embodiment that does not include the discharge switching element 64 and the discharge signal generation circuit 72, the time t4 when an abnormality occurs in the switching element S # and the propagation signal x # switches to logic "H" The delay time Tg (see FIG. 10) between time t14 can be shortened, and the occurrence of an abnormality in switching element S # can be transmitted early.

(Other embodiments)
In the above embodiment, the signal to be propagated may be propagated from the low pressure system Syl to the high pressure system Syh. In this case, the information to be propagated may be, for example, information on the switching speed of the switching element S #. Specifically, in the case of propagating the first information to the effect that the switching speed is high, the logic "H" and the logic "L" are switched every predetermined prescribed period. On the other hand, in the case of propagating the second information indicating that the switching speed is low, it always becomes logic "L" or logic "H". Also, if it is possible to propagate from the high pressure system Syh to the low pressure system Syl and then propagate it from the low pressure system Syl to the high pressure system Syh again, it propagates from the low pressure system Syl to the high pressure system Syh and then from the high pressure system Syh to the low pressure system It may be propagated to Syl again.

  In the first embodiment, a circuit that detects that an abnormality has occurred in the switching element S # based on the difference between the logical value of the prescribed signal r # and the logical value of the propagation signal x # (switching signal c #) is: It is not limited to the exclusive OR circuit. For example, it may be a negative exclusive OR circuit.

  In the seventh and eighth embodiments, the inductor element 58 is connected to the high voltage side of the second photodiode 36 of the second photocoupler 34. However, the present invention is not limited to this. It may be connected to the low voltage side of the second photodiode 36, that is, between the second photodiode 36 and the second drive switching element 56.

  In the first to fifth embodiments, the form in which the insulating element is a photocoupler is exemplified, but the present invention is not limited to this. The insulating element may be a magnetic coupler. FIG. 13 is a circuit diagram of an interface 16 according to another embodiment corresponding to the second embodiment. The interface 16 comprises magnetic couplers 80, 82 that isolate the high pressure system Syh from the low pressure system Syl.

  The magnetic coupler 82 includes third and fourth drive switching elements 84 and 86, first and second magnetic circuits 88 and 90, and fifth and sixth drive switching elements 92 and 94. In the high voltage system Syh, the high voltage system power supply 50 is connected to the first magnetic circuit 88 via the third drive switching element 84, and the first magnetic circuit 88 is connected via the fourth drive switching element 86. It is connected to the ground of high voltage system Syh. The gates of the third and fourth drive switching elements 84 and 86 are connected to the drive circuit DU. The switching signal c # is input from the driving circuit DU to the gates of the third and fourth driving switching elements 84 and 86, and switching between the on state and the off state is performed by the switching signal c #.

  Specifically, when the switching signal c # becomes logic "L", the third drive switching element 84 is turned off, and the fourth drive switching element 86 is turned on. In this case, the ground voltage of the high voltage system Syh is input to the first magnetic circuit 88, and no current flows in the coil in the first magnetic circuit 88. On the other hand, when the switching signal c # becomes logic "H", the third drive switching element 84 is turned on, and the fourth drive switching element 86 is turned off. As a result, the voltage of the high voltage system power supply 50 is input to the first magnetic circuit 88, and a current flows in the coil in the first magnetic circuit 88. The first magnetic circuit 88 and the second magnetic circuit 90 form a transformer, and when a current flows in the coil in the first magnetic circuit 88, a current flows in the coil in the second magnetic circuit 90.

  In the low voltage system Syl, the low voltage system side power supply 40 is connected to the microcomputer 20 via the fifth drive switching element 92, and the microcomputer 20 is connected to the ground of the low voltage system Syl via the sixth drive switching element 94. It is connected. The gates of the fifth and sixth drive switching elements 92 and 94 are connected to the second magnetic circuit 90. A control signal is input from the second magnetic circuit 90 to the gates of the fifth and sixth drive switching elements 92 and 94 based on the current flowing through the coil in the second magnetic circuit 90. The on state and the off state are switched.

  Specifically, when the fifth drive switching element 92 is turned on and the sixth drive switching element 94 is turned off, the voltage of the low voltage system side power supply 40 is input to the microcomputer 20. That is, the propagation signal x # becomes logic "H". On the other hand, when the fifth drive switching element 92 is turned off and the sixth drive switching element 94 is turned on, the ground voltage of the low voltage system Syl is input to the microcomputer 20. That is, the propagation signal x # becomes logic "L". The structure of the magnetic coupler 80 is the same as that of the magnetic coupler 82, and therefore the description thereof is omitted.

  In the magnetic couplers 80 and 82, the first magnetic circuit 88 and the second magnetic circuit 90 form a transformer. Thereby, switching signal c # can be propagated while insulating high voltage system Syh from low voltage system Syl. In the magnetic couplers 80 and 82, the switching signal c # includes the off command period Tb in the period in which the switching element S # is normal, thereby suppressing the power consumption in the first and second magnetic circuits 88 and 90. can do.

  In the above embodiment, the microcomputer 20 may not generate the definition signal r #. That is, the drive circuit DU itself may generate the drive signal g #. In this case, the microcomputer 20 may obtain the drive signal g # from the drive circuit DU. In this case, the drive signal g # is a period signal. Further, for example, when the cycle of the drive signal g # is defined in advance, the microcomputer 20 may not necessarily acquire the drive signal g #.

  12: Inverter, 16: Interface, 20: Microcomputer, 34: Photocoupler, switching signal generation circuit: 70, 100: Control system, DU: Drive circuit, Syh: High voltage system, Syl: Low voltage system, Ta: ON command period, Tb: OFF command period, c #: Switching signal.

Claims (10)

The binary switching signal (c #) of logic "H" and logic "L" is transferred from the high voltage system (Syh) or the low voltage system (Syl) to the other system via the isolation element (34) In the signal propagation device (100) propagating to
A second logic signal provided in the one system and having a logic different from the first logic signal for driving the insulating element or the first logic signal for stopping driving the insulating element is generated as the switching signal. A switching signal generator (70);
When propagating the first information to the other system, the switching signal generation unit generates the first logic signal or the second logic signal as the switching signal, and the first switching signal is different from the first information. 2. A signal propagation device that generates a signal having a defined cycle (Tn) composed of the first logic signal and the second logic signal as the switching signal when propagating 2 information to the other system. A third drive signal (g #) provided in the one system, which is a binary “H” and “L” binary drive signal, for driving the one system, and a drive of the one system And a drive signal acquisition unit (74) for acquiring a drive signal having the prescribed cycle which is composed of a fourth logic signal different from the third logic signal for stopping the second logic signal.
The switching signal generation unit outputs the first logic signal as a switching signal during a period in which the second signal is propagated to the other system, and the driving signal is the third logic signal as the switching signal. The signal propagation device according to claim 1, generating a signal to be the second logic signal during a period in which the signal is the fourth logic signal. In the other system, it is a binary period signal (r #) of logic "H" and logic "L", and becomes a fifth logic signal in a period in which the drive signal is the third logic signal, A period acquisition unit (22) for acquiring a period signal which becomes a sixth logic signal of a logic different from the fifth logic signal in a period in which the drive signal is the fourth logic signal;
A detection signal generation is provided in the other system, and generates a detection signal (z #) for detecting the first information based on the difference between the logic value of the period signal and the logic value of the switching signal. Part (48),
The signal propagation device according to claim 2, comprising A third drive signal (g #) provided in the one system, which is a binary “H” and “L” binary drive signal, for driving the one system, and a drive of the one system And a drive signal acquisition unit (74) for acquiring a drive signal having the prescribed cycle which is composed of a fourth logic signal different from the third logic signal for stopping the second logic signal.
The switching signal generation unit transmits the second information to the other system as the switching signal during a part of a period in which the drive signal is the fourth logic signal. The signal propagation device according to claim 1, wherein the second logic signal is generated during another period.   The signal propagation device according to claim 4, wherein the start timing of the first logic signal is equal to the start timing of the fourth logic signal in a period during which the second information is propagated to the other system. A third drive signal (g #) provided in the one system, which is a binary “H” and “L” binary drive signal, for driving the one system, and a drive of the one system And a drive signal acquisition unit (74) for acquiring a drive signal having the prescribed cycle which is composed of a fourth logic signal different from the third logic signal for stopping the second logic signal.
The switching signal generation unit outputs the second logic signal as a switching signal during a period in which the second signal is propagated to the other system, and the driving signal is the third logic signal. The signal propagation device according to claim 1, generating a signal to be the first logic signal during a period in which the signal is the fourth logic signal. A third drive signal (g #) provided in the one system, which is a binary “H” and “L” binary drive signal, for driving the one system, and a drive of the one system And a drive signal acquisition unit (74) for acquiring a drive signal composed of a fourth logic signal different from the third logic signal for stopping the second logic signal.
The drive signal includes a plurality of drive periods serving as the third logic signal, and includes a plurality of drive periods having different lengths.
The signal propagation device according to claim 1, wherein the specified period is set shorter than the shortest period of the drive period. A third drive signal (g #) provided in the one system, which is a binary “H” and “L” binary drive signal, for driving the one system, and a drive of the one system And a drive signal acquisition unit (74) for acquiring a drive signal having the prescribed cycle which is composed of a fourth logic signal different from the third logic signal for stopping the second logic signal.
The switching signal generation unit transmits the second information to the other system as the switching signal at the start timing and the end timing of the period in which the drive signal is the third logic signal. The signal propagation device according to claim 1, which generates a signal which becomes a logic signal and becomes the second logic signal in other periods. The insulating element is a photocoupler,
An inductor element (58) provided in the one system and connected in series with the photodiode of the photocoupler;
A conductive state provided in the one system, connected in series to a high voltage side or a low voltage side of an element group including the photodiode and the inductor element, and driving the insulating element by the switching signal; A drive switching element (56) that switches to a cutoff state for stopping the drive;
A reflux diode (60) provided in the one system and connected antiparallel to the element group;
The signal propagation apparatus according to any one of claims 1 to 8, comprising: A discharge switching element (64) provided in the one system and connected between an anti-parallel circuit of the element group and the free wheeling diode and a predetermined reference voltage;
A period provided in the one system and in a period during which the second information is propagated to the other system, the discharge switching element is maintained in a cutoff state, and the second information is propagated to the other system A discharge signal generation unit (72) for switching the discharge switching element to the conductive state at the end timing of the and generating a discharge signal for discharging the charge of the anti-parallel circuit to the reference voltage;
The signal propagation device according to claim 9, comprising

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