JP2017212770A - Abnormality detection device and power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a configuration capable of specifically identifying an abnormal portion in a power supply device in which voltage conversion can be performed by multiple voltage conversion parts.SOLUTION: An abnormality detection device 3 comprises a control part 4 defining, as a control target, a multi-phase conversion part 2 including multiple voltage conversion parts CV each for converting an input voltage through an ON/OFF operation of a switch element. The control part 4 is configured to output a control signal for alternately switching an ON signal and an OFF signal to each of the switch elements provided in each of the voltage conversion parts CV of the multi-phase conversion part 2 and performs operation stop control for gradually increasing the number of the voltage conversion parts CV to stop operating upon the multi-phase conversion part 2 in predetermined timing. The control part 4 is functioned as an identification part and identifies one or more voltage conversion parts CV in which abnormality occurs based on a change at least in the output current or an output voltage from the multi-phase conversion part 2 during a period in which the operation stop control is performed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an abnormality detection device and a power supply device.

  Patent Document 1 includes a multiphase chopper that includes a plurality of chopper units connected in parallel, switches the switch elements of each phase chopper unit in different phases, and converts a DC voltage from a power generator into a predetermined output voltage. And a failure detection means for detecting a failure of the switch element of each phase chopper section is disclosed.

JP 2013-46541 A

  The power supply device of Patent Document 1 acquires an output current value at the timing of the falling (or rising) edge of the control signal for the switching element of each phase chopper unit, and outputs a judgment if there is a difference between the acquired current values. The current is limited. However, the technique disclosed in Patent Document 1 has a problem in that a part where a failure has occurred in a plurality of voltage conversion units (each phase chopper unit) connected in parallel cannot be specifically identified.

  The present invention has been made based on the above-described circumstances, and an object thereof is to provide a device that can specifically identify an abnormal portion of a power supply device that can perform voltage conversion by a plurality of voltage conversion units. It is what.

An anomaly detection apparatus which is an example of the present invention,
Each of the switch elements provided in each of the voltage conversion units of the multiphase conversion unit is controlled by a multiphase conversion unit including a plurality of voltage conversion units that step up or down an input voltage by an on / off operation of the switch element. The operation stop control is configured to output a control signal that alternately switches between an on signal and an off signal, and to gradually increase the number of the voltage conversion units that stop the operation of the polyphase conversion unit at a predetermined time. A control unit for performing
Based on a change in at least one of an output current and an output voltage from the multiphase converter during a period in which the control unit performs the operation stop control, the one or more voltage converters in which an abnormality has occurred are identified. A specific part,
including.

  In the abnormality detection device described above, the control unit performs operation stop control that gradually increases the number of voltage conversion units that stop the operation of the multiphase conversion unit at a predetermined time. In this configuration, when one or a plurality of voltage conversion units are switched from the operating state to the stopped state by the operation stop control, if the switching target is normal, the output of the polyphase conversion unit is before and after the switching. If it changes appropriately and the switching target is abnormal (for example, switching element open abnormality, etc.), the output of the polyphase converter will show an abnormal change before and after switching. Using such a feature, the specifying unit has an abnormality based on a change in at least one of the output current and the output voltage from the multiphase conversion unit during the period in which the control unit performs the operation stop control. A plurality of voltage conversion units are specified. Therefore, according to this structure, the abnormal part of the power supply device which can perform voltage conversion by several voltage conversion parts can be specified specifically.

1 is a circuit diagram illustrating an in-vehicle power supply system including an abnormality detection device and a power supply device according to a first embodiment. 3 is a flowchart illustrating a flow of abnormality determination control in the abnormality detection device according to the first embodiment. 3 is a flowchart illustrating the flow of redetermination control in the abnormality detection device according to the first embodiment. 5 is a graph illustrating a change in output current during operation stop control when an abnormality occurs in the second phase in the power supply device including the abnormality detection device according to the first embodiment. 6 is a graph illustrating a change in output current during operation stop control when an abnormality occurs in the m-th phase in the power supply device including the abnormality detection device according to the first embodiment.

Here, a desirable example of the invention will be shown.
The control unit may be configured to perform operation stop control when a stop condition for stopping the operation of the vehicle is satisfied.

  According to this configuration, since the operation stop control that gradually increases the number of voltage conversion units that stop the operation can be performed at the time when the operation of the vehicle is stopped (that is, when the vehicle is not traveling), It is possible to perform the stop operation for specifically identifying the vehicle while suppressing the influence on the vehicle operation.

  When one or a plurality of voltage converters in which an abnormality has occurred are specified by the specifying unit when the operation stop control is performed according to the establishment of the stop condition, the control unit It may be configured to selectively operate one or a plurality of voltage conversion units identified as abnormal by the identification unit in the operation stop control. And the abnormality detection device is based on at least one of the output current or the output voltage from the multiphase converter when the one or more voltage converters are selectively operated when the next vehicle start condition is established, It may be determined whether or not one or a plurality of voltage converters that are selectively operated is abnormal, and may have a protective operation unit that performs a predetermined protective operation when abnormal.

  According to this configuration, when one or a plurality of voltage conversion units are specified as an abnormal part when an abnormality is detected at the time when the vehicle is stopped, it is determined whether the specified part is abnormal or not. Can be confirmed again. By such a method, it is possible to determine abnormality with high certainty. In addition, since the abnormality determination is performed a plurality of times at the time when the vehicle operation is stopped and the next start time, the operation stop control and the abnormality re-determination are less likely to affect the vehicle operation such as traveling.

  The control unit is configured to control the driving of all the voltage conversion units so that the output current or the output voltage from the multiphase conversion unit becomes the first target value during normal control in which all the voltage conversion units are operated. Also good. When one or more voltage converters are selectively operated when the next vehicle start condition is satisfied, the output current or the output voltage is selected to be a second target value smaller than the first target value. Alternatively, the driving of a plurality of voltage conversion units may be controlled.

  When re-decisioning by selectively operating a part that has a high possibility of abnormality, the voltage converter to be operated may generate an excessive output that is different from normal, so the target value is suppressed as in the above configuration. If the re-determination is performed by the operation, the excessive output at the time of re-determination is easily suppressed.

  In the period when the control unit performs the operation stop control, the specifying unit has a predetermined amount of variation in the output current or the output voltage before and after switching when any one or a plurality of voltage conversion units are switched from the operation state to the stop state. In the case of the following, the configuration may be such that one or a plurality of voltage conversion units that are switched so that the fluctuation amount is equal to or less than a predetermined value are determined to be abnormal.

  If abnormality determination is performed by such a method, it is possible to more accurately identify an abnormal portion where sufficient output is not made.

  In the period during which the control unit performs the operation stop control, the specifying unit is configured such that the output current or the output voltage exceeds a predetermined output threshold because any one or a plurality of voltage conversion units are switched from the operation state to the stop state. When there is a residual voltage conversion unit that changes from a state to a state below a predetermined output threshold and is not switched to a stopped state after the change, the remaining voltage conversion unit that exists after the change is determined to be abnormal. Also good.

  If abnormality determination is performed by such a method, it is possible to more accurately identify an abnormal portion where sufficient output is not performed, and it is possible to end abnormality determination for all voltage conversion units earlier.

  The power supply device can be configured to include the abnormality detection device and the polyphase conversion unit. According to this configuration, it is possible to realize a power supply device that exhibits the same effect as the abnormality detection device.

<Example 1>
Embodiment 1 of the present invention will be described below.
The power supply device 1 shown in FIG. 1 is configured as an on-vehicle multiphase DCDC converter, and converts a DC voltage (input voltage) applied to the input-side conductive path 6 by a multiphase method and a step-down method, The output voltage obtained by stepping down the input voltage is output to the output-side conductive path 7. Furthermore, the power supply device 1 includes an abnormality detection device 3.

  The power supply device 1 includes a power supply line 5 having an input-side conductive path 6 and an output-side conductive path 7, and n voltage conversion units CV1, CV2,... CVn that convert and output an input voltage. Phase conversion unit 2 and voltage conversion units CV1, CV2,... CVn are individually controlled by control signals. Note that n, which is the number of voltage conversion units (the maximum number of phases in the multiphase conversion unit 2), may be a natural number of 2 or more. In the following, the configuration shown in FIG. 1, that is, the case where n = 4 will be described as a representative example.

  Below, the example in which the abnormality detection apparatus 3 is comprised by the control part 4 is demonstrated as a representative example. However, this example is merely an example, and the abnormality detection device 3 may be configured to include parts other than the control unit 4.

  The input side conductive path 6 is configured as, for example, a primary side (high voltage side) power supply line to which a relatively high voltage is applied, and is connected to a high potential side terminal of the primary side power supply unit 91 and the primary side thereof. A predetermined DC voltage (for example, 48V) is applied from the power supply unit 91. The input side conductive path 6 is connected to the individual input paths LA1, LA2, LA3, LA4 of the voltage converters CV1, CV2, CV3, CV4, respectively. The primary power supply unit 91 is configured by power storage means such as, for example, a lithium ion battery or an electric double layer capacitor, the high potential side terminal is maintained at a predetermined high potential (for example, 48 V), and the low potential side terminal is, for example, It is kept at ground potential (0V). Further, a generator 90 configured as an alternator is also connected to the input side conductive path 6.

  The output side conductive path 7 is configured as a secondary (low voltage side) power supply line to which a relatively low voltage is applied. The output-side conductive path 7 is connected to the output-side conductive path 7 with a storage means (such as a lead storage battery) that outputs a DC voltage (for example, 12 V) smaller than the output voltage of the primary-side power supply unit 91. The output-side conductive path 7 is also connected to a load (not shown) such as an on-vehicle electric device.

  A multiphase converter 2 is provided between the input side conductive path 6 and the output side conductive path 7. The multiphase converter 2 includes n voltage converters CV1, CV2,... CVn connected in parallel between the input side conductive path 6 and the output side conductive path 7. The n voltage converters CV1, CV2,... CVn have the same configuration and all function as a synchronous rectification step-down converter. Hereinafter, each of the n voltage converters CV1, CV2,... CVn is also referred to as a voltage converter CV. The individual input paths LA1, LA2,... LAn of the n voltage converters CV1, CV2,. The individual output paths LB1, LB2,... LBn of the n voltage conversion units CV1, CV2,... CVn are connected to the output side conductive path 7 that is a common output path. Note that the n voltage converters CV1, CV2,... CVn are in the first phase, the second phase, and the n phase, respectively. In the present specification, the “voltage conversion unit corresponding to the phase” may be simply referred to as “phase”.

  Of the n voltage converters CV1, CV2,... CVn, the k-th phase voltage converter CVk will be described. In the following, k is a natural number of n or less. The k-th phase voltage converter CVk includes a high-side switch element SAk, a low-side switch element SBk, an inductor Lk, and a protective switch element SCk. For example, the first-phase voltage conversion unit CV1 includes a high-side switch element SA1, a low-side switch element SB1, an inductor L1, and a protective switch element SC1. The conversion unit CV2 includes a high-side switch element SA2, a low-side switch element SB2, an inductor L2, and a protective switch element SC2. The same applies to the third phase and the fourth phase.

  In the k-th phase voltage converter CVk, the switch element SAk is configured as an N-channel MOSFET, and the individual input path LAk branched from the input-side conductive path 6 is connected to the drain of the switch element SAk. The source of the switch element SAk is connected to the drain of the low-side switch element SBk and one end of the inductor Lk. The switch element SBk has a drain connected to a connection point between the switch element SAk and the inductor Lk, and a source connected to the ground. The other end of the inductor Lk is connected to the source of the switch element SCk. The drain of the switch element SCk is connected to the output side conductive path 7. The switch element SCk functions to cut off the conduction of the path when an abnormality such as overcurrent, overvoltage, or reverse flow occurs. In FIG. 1, control lines connected to the gates of the switch elements SAk, SBk, and SCk are omitted. However, the switch elements SAk, SBk, and SCk are controlled by the control unit 4 via individual control lines. obtain.

  The control unit 4 mainly includes a control circuit 10 and a PWM drive unit 18. The control circuit 10 includes a microcomputer having a CPU, for example. The control circuit 10 includes a part (CPU or the like) that functions as a specific unit and a protection operation unit, which will be described later, a storage unit configured by ROM, RAM, and the like, and an A / D converter that converts an analog voltage into a digital signal 16. Each voltage value output from a current detection circuit 9A, a voltage detection circuit 9B, etc., which will be described later, is input to the A / D converter 16.

  In the control unit 4, the control circuit 10 has a function of determining a duty ratio and a function of generating and outputting a PWM signal of the determined duty ratio. Specifically, the n voltage conversion units CV1, A PWM signal for each of CV2... CVn is generated and output. For example, when driving all the n voltage converters CV1, CV2,... CVn in a steady output state, the control circuit 10 generates PWM signals having phases different by 2π / n, and the n voltage converters CV1, CV1, CV1,. Output to each of CV2... CVn. If the polyphase converter 2 is constituted by four voltage converters CV1, CV2, CV3, and CV4 as in the example of FIG. 1, the PWM signals having phases different from each other by 2π / 4 from the controller 4 respectively. Is given.

  Based on the PWM signal for each phase generated by the control circuit 10, the PWM drive unit 18 turns on each of the switch elements SAk and SBk (k is a natural number of 1 to n) of each phase alternately. Is applied to the gates of the switch elements SAk and SBk. The phase of the signal applied to the gate of the switch element SBk during the output of the PWM signal to the switch elements SAk and SBk is reversed with respect to the signal applied to the gate of the switch element SAk after ensuring the dead time.

  The power supply device 1 includes detection units that detect values reflecting output current and output voltage in a common output path (output-side conductive path 7) from the plurality of voltage conversion units CV1, CV2,. The current detection circuit 9A may be configured to output a voltage value corresponding to the current flowing through the output side conductive path 7 as a detection value. For example, the current detection circuit 9 </ b> A has a resistor and a differential amplifier that are interposed in the output-side conductive path 7. The voltage drop generated in the converter is amplified by the differential amplifier, and this is output as a detection value to the A / D converter 16 of the control circuit 10. The voltage detection circuit 9B outputs, for example, a value reflecting the voltage of the output-side conductive path 7 (for example, the voltage of the output-side conductive path 7 or a divided value) to the A / D converter 16 of the control circuit 10. Configured as part. In the following description, the detection value output from the current detection circuit 9A is referred to as “detection current value”, and the detection value output from the voltage detection circuit 9B is described as “detection voltage value”.

Next, drive control of the multiphase converter 2 performed by the controller 4 will be described.
First, the basic operation in the steady state will be described. The basic operation in the steady state is an operation before the process of FIG. 2 described later is executed, and is an operation after the process of FIG. 3 described later is executed. The control unit 4 has a multiphase conversion unit 2 including a plurality of voltage conversion units CVk (k is a natural number of 1 to n) as a control target, and is provided in each voltage conversion unit CVk of the multiphase conversion unit 2. Each switch element SAk, SBk has a function of outputting a control signal for alternately switching on and off signals.

  In the steady state, the control unit 4 complementarily outputs a PWM signal with a dead time set for each of the n voltage conversion units CV1, CV2,... CVn. For example, for each gate of the switch elements SAk and SBk constituting the k-th phase voltage conversion unit CVk, the control unit 4 sets a dead time and then outputs an ON signal to the gate of the switch element SAk. During the output of the off signal to the gate of the switch element SBk, the on signal is output to the gate of the switch element SBk. In response to such a complementary PWM signal, the voltage conversion unit CVk performs switching between the ON operation and the OFF operation of the switch element SAk in synchronization with the switching between the OFF operation and the ON operation of the switch element SBk. As a result, the DC voltage applied to the individual input path LAk is stepped down and output to the individual output path LBk. The output voltage of the individual output path LBk is determined according to the duty ratio of the PWM signal applied to each gate of the switch elements SAk and SBk. Such control is similarly performed in any of the above-described natural numbers k from 1 to n, that is, in any voltage conversion unit from the first phase to the n-th phase.

  When operating the polyphase converter 2, the controller 4 individually controls a part or all of the plurality of voltage converters CV1, CV2,... CVn with a control signal (PWM signal). The feedback control is performed so that the output becomes the set target value. Specifically, the control unit 4 is based on the detection value (current value of the output side conductive path 7) input to the control circuit 10 by the current detection circuit 9A and the target value (target current value) of the output current. The control amount (duty ratio) of each phase is determined by feedback calculation using a known PID control method. For example, in a steady output state when the number of drive phases is m, a PWM signal having a duty ratio determined by feedback calculation is output to each of the m voltage conversion units with a phase difference of 2π / m. Note that when all n voltage converters are driven, n = m. When not driving the p voltage converters among the n voltage converters due to failure determination described later, m = n-p.

Next, the abnormality determination control will be described with reference to FIG.
In the power supply device 1 shown in FIG. 1, the control unit 4 performs operation stop control (control for gradually increasing the number of voltage conversion units CV for stopping operation) on the polyphase conversion unit 2 at a predetermined time, Make a decision. Specifically, when a stop condition for stopping the operation of the vehicle is established (for example, an ignition switch (not shown) is turned off, and an IG off signal indicating that the ignition switch is turned off is input to the control unit 4). Until the end of the abnormality determination control shown in FIG. 2 is the “predetermined time”. The control unit 4 executes the abnormality determination control shown in FIG. 2 according to the establishment of the stop condition described above, and switches the operation of the polyphase conversion unit 2 from the operation in the steady state described above. Then, the control unit 4 performs operation stop control that gradually increases the number of voltage conversion units CV that stop the operation during the abnormality determination control shown in FIG. Further, the control unit 4 (specifically, the control circuit 10) functions as a specific unit, and the output current from the polyphase conversion unit 2 during the period in which the abnormality determination control in FIG. 2 is performed (period during which operation stop control is performed). On the basis of the change, the one or more voltage converters in which an abnormality has occurred are identified.

  When the control unit 4 switches the control from the above-described steady state control to the abnormality determination control of FIG. 2, immediately after the switching, the control unit 4 is in a steady state so that the output current from the multiphase conversion unit 2 becomes the target current value X1. The m voltage converters CV that have been operating in the state are operated in the same manner as in the steady state. That is, the feedback control described above is performed on the m voltage converters CV. Note that the target current value X1 used for feedback control when performing the abnormality determination control of FIG. 2 may be the same as or smaller than the target current value used for steady-state control. In the case where all of the n number of voltage conversion units CV in the multiphase conversion unit 2 have failed in some of the voltage conversion units CV, and the number of operations m in the steady state is less than n, FIG. Immediately after the start of the abnormality determination control indicated by 2, the operation of the m voltage converters CV is continued.

  In the abnormality determination control of FIG. 2, first, i = 1 is set in step S <b> 1, and one of the m phases (m voltage conversion units CV) is selected as a target of attention. To do. The value of i is a value indicating the number of the phase of interest (voltage converter CV) among m phases (voltage converter CV). Note that in the m voltage converters CV, the number (order) can be determined in a predetermined manner, and the manner of determination is not particularly limited.

  The control unit 4 performs the process of step S2 after step S1 or after step S10 described later, and stops the operation of the i-th phase (voltage conversion unit CV). When the process of step S2 is performed immediately after step S1, the control unit 4 stops the operation of the first phase (voltage conversion unit CV), and the process of step S2 is performed after the process of step S10. The control unit 4 stops the operation of the i-th phase (voltage conversion unit CV) specified by i updated in step S10.

  In the process of step S3 after step S2, the control unit 4 determines whether or not the output current from the polyphase conversion unit 2 is equivalent to 0 (A) for a predetermined time t. Specifically, the detection value (detection current value) input from the current detection circuit 9A to the control unit 4 immediately after the operation stop process of the i-th phase is performed in step S2 until the predetermined time t elapses. Is less than or equal to a predetermined output threshold indicating a non-energized state.

  When the control unit 4 determines that the condition is satisfied in the process of step S3, that is, immediately after the operation stop process is performed in S2, until the predetermined time t elapses, the control unit 4 inputs the control unit 4 from the current detection circuit 9A. If it is determined that the detected value (detected current value) is equal to or less than the predetermined output threshold value (YES in step S3), the process proceeds to step S4.

  In the process of step S4, the control unit 4 determines the total number of operations when the number i of the target phase (target voltage conversion unit CV) starts the abnormality determination control in FIG. It is determined whether or not the number of operating phases is equal to m. If it is determined that i = m (YES in step S4), the process proceeds to step S5, and the m-th in the process of step S5. The phase (last voltage conversion unit CV) is determined to be normal. Conversely, when it is determined in the process of step S4 that i and m do not match (NO in step S4), the control unit 4 determines the remaining phase (i + 1-th to m-th voltage conversion unit) in step S6. CV) is temporarily determined to be a failure, and the i-th phase (voltage conversion unit CV) is determined to be normal.

  On the other hand, if the control unit 4 determines that the condition is not satisfied in the process of step S3, that is, immediately after the operation stop process is performed in S2, the current detection circuit 9A controls the control unit When it is determined that the detected value (detected current value) input to 4 exceeds a predetermined output threshold (NO in step S3), the process proceeds to step S7. In step S7, the control unit 4 determines whether or not the output current from the multiphase conversion unit 2 does not fluctuate for a predetermined time t. Specifically, the output current from the multiphase converter 2 from the time immediately before stopping when the operation of the i-th phase (voltage converter CV) is stopped in step S2 until the predetermined time t elapses. It is determined whether or not the fluctuation amount is less than a predetermined value. The predetermined value is a value larger than 0 and smaller than the target current value X1, and may be a value smaller than X1 / m, for example.

  When it is determined that the condition is satisfied in the determination in step S7, that is, when the predetermined time t elapses from the time immediately before the operation of the i-th phase (voltage conversion unit CV) is stopped in step S2, the control unit 4 When it is determined that the fluctuation amount of the output current from the multiphase converter 2 during the period is equal to or less than a predetermined value, the process proceeds to step S8, and the i-th phase (voltage converter CV) is provisionally determined to be faulty. . Conversely, the fluctuation amount of the output current from the multi-phase conversion unit 2 from the time immediately before stopping the operation of the i-th phase (voltage conversion unit CV) in step S2 until the predetermined time t elapses is predetermined. When it is determined that the value is exceeded, the process proceeds to step S9, and the i-th phase (voltage conversion unit CV) is determined to be normal.

  The control unit 4 increments the value of i in step S10 regardless of which of the processes in steps S8 and S9 is performed. That is, 1 is added to the value of i set before step S10, and the value after the addition is set as a new i. And control part 4 will transfer processing to Step S2, after Step S10 is completed, and will perform processing after Step S2 similarly with the flow mentioned above.

  In this configuration, the control circuit 10 corresponds to an example of a specific unit, and the voltage conversion unit in which an abnormality has occurred based on the change in the output current from the multiphase conversion unit 2 during the period in which the control unit 4 performs the operation stop control. It has a function to specify CV. In the above-described example, the voltage converter CV that is provisionally determined to be a failure in step S6 or step S8 corresponds to the “voltage converter having an abnormality”.

  Specifically, the control circuit 10 corresponding to the specifying unit is configured to perform the processes of steps S3, S4, S5, and S6, and any voltage conversion unit is in a period during which the control unit 4 performs the operation stop control. Residual voltage converter that changes from a state in which the output current exceeds a predetermined output threshold to a state below a predetermined output threshold due to the CV being switched from the operating state to the stopped state, and is not switched to the stopped state after the change When CV exists, it is determined that the remaining voltage conversion unit CV existing after the change is abnormal (specifically, a temporary failure).

  In addition, the control circuit 10 corresponding to the specifying unit is configured to perform the processes of steps S7, S8, and S9, and any voltage conversion unit CV is in an operating state during the period in which the control unit 4 performs the operation stop control. The amount of fluctuation in the output current before and after switching when switching to the stop state (specifically, the difference between the maximum value and the minimum value of current during a predetermined time t from the time immediately before the operation is stopped in step S2) ) Is equal to or less than a predetermined value (that is, when YES is determined in step S7), the voltage conversion unit CV that has been switched so that the fluctuation amount is equal to or less than the predetermined value is abnormal (specifically, a temporary failure). judge.

Next, the redetermination control will be described with reference to FIG.
As described above, the control unit 4 performs the operation stop control according to the establishment of the stop condition (specifically, the input of the ignition off signal to the control unit 4), and the voltage conversion unit CV in which an abnormality has occurred. Try to identify. When the voltage conversion unit CV in which an abnormality has occurred during the operation stop control is identified, the control unit 4 converts the voltage conversion identified as abnormal in the previous operation stop control when the next vehicle start condition is satisfied. The part CV is selectively operated.

  The control unit 4 controls the above-described steady state when the vehicle is started (specifically, when an IG ON signal indicating that the ignition switch has been switched to the ON state is input to the control unit 4). Prior to this, redetermination control shown in FIG. 3 is performed. Before the redetermination control in FIG. 3 is performed, all the voltage conversion units CV of the multiphase conversion unit 2 are maintained in the operation stopped state.

  In the redetermination control shown in FIG. 3, it is first determined whether or not there is a phase (voltage conversion unit CV) that is provisionally determined to be a failure. Specifically, in the abnormality determination control performed when the vehicle was stopped last time (that is, the latest abnormality determination control performed before the re-determination control in FIG. 3), one of the voltage conversion units CV has failed. It is determined whether or not provisional determination has been made. In the abnormality determination control (FIG. 2) performed at the time of the previous stop of the vehicle, when the process of S6 or S8 is performed and any of the voltage conversion units CV is provisionally determined to be faulty, the process proceeds to step S11. Of the total number n of voltage conversion units CV, only the voltage conversion unit CV (that is, the phase temporarily determined to be a failure when the vehicle was stopped last time) is selectively operated. When selectively operating some voltage conversion units CV in step S11, the control unit 4 uses the output current from the multiphase conversion unit 2 (that is, the output current from the selected voltage conversion unit CV) as a target current value. The above-described feedback control is performed on the voltage converter CV selected to be X2. In step 11 of FIG. 3, the target current value X2 used for feedback control when operating the selected voltage converter CV is set to be smaller than the target current value X1 used in the above-described abnormality determination control.

  As described above, the control unit 4 outputs the output current from the multiphase conversion unit 2 during normal control in which all the voltage conversion units CV are operated (when all the n voltage conversion units CV are operated in a steady state). The drive of all the voltage converters CV is controlled so as to be the first target value (for example, the target current value X1). On the other hand, when the voltage conversion unit CV is selectively operated when the next vehicle start condition is satisfied after the abnormality determination control of FIG. 2, the output current is the first target value (for example, the target current value X1). The drive of the voltage conversion unit CV selected so as to be smaller than the second target value (target current value X2) is controlled, and the step-down operation is performed only by the selected voltage conversion unit CV.

  If any of the voltage converters CV is selectively operated in step S11, is the target output being made (that is, the output current when any of the voltage converters CV is selectively operated in step S11)? Whether or not the value has reached a predetermined current value). If it is determined in step S12 that the output current value has reached the predetermined current value, the control unit 4 shifts the process to step S13 and operates the voltage conversion unit CV operated in step S11 (that is, the abnormality in FIG. 2). The temporary determination of failure for the phase temporarily determined as failure in the determination control is canceled, and the voltage conversion unit CV is determined to be normal. Conversely, when it is determined in step S12 that the output current value has not reached the predetermined current value, the control unit 4 shifts the process to step S14 and operates the voltage conversion unit CV operated in step S11 (that is, a failure). Are re-determined as abnormal (failure). After step S13 or step S14, the re-determination control in FIG. 3 is terminated, and the control proceeds to the steady state control described above.

  In this configuration, when any voltage conversion unit CV is redetermined to be abnormal in the redetermination process of FIG. 3 (when it is determined to be faulty in S14), the abnormality (failure) of the voltage conversion unit CV is determined. . In the steady state control performed after FIG. 3, the voltage conversion unit CV in which an abnormality (failure) is determined in S <b> 14 is not operated and the remaining voltage conversion unit CV is operated to perform voltage conversion. .

  In this configuration, the control unit 4 (specifically, the control circuit 10) corresponds to an example of a protection operation unit, and after the abnormality determination control in FIG. 2, the voltage conversion unit CV is selectively selected when the next vehicle start condition is satisfied. Based on one of the output currents from the polyphase converter 2 when it is operated normally, it is determined whether or not the selectively operated voltage converter CV is abnormal. To function. In the above-described example, as an example of the protection operation, the example of prohibiting the operation of the voltage conversion unit CV that has been re-determined as abnormal (failure) in S14 is shown, but the protection operation is not limited to this example. The operation may be such that information indicating that the voltage conversion unit CV that has been determined to be abnormal (failure) in S14 is abnormal is notified to an external device (for example, a host ECU).

  If the control unit 4 determines in step S10 of FIG. 3 that there is no phase (voltage conversion unit CV) that is provisionally determined to be a failure, the process of FIG. 3 ends. In this case, the process proceeds to the above-described steady state control without performing steps S11 to S14.

  In the above description, an example is shown in which one of the voltage conversion units CV is provisionally determined to be faulty (abnormal) in the abnormality determination control of FIG. 2, but a plurality of voltage conversion units CV are detected in the abnormality determination control of FIG. 2. 3 is temporarily determined as a failure (abnormal), the processing of steps S11 to S14 in FIG. 3 is performed on each voltage conversion unit CV, and the failure (abnormality) of each voltage conversion unit CV is individually re-determined. That's fine.

  As described above, in the abnormality detection device 3 of this configuration, the control unit 4 performs operation stop control that gradually increases the number of voltage conversion units CV that cause the polyphase conversion unit 2 to stop operation at a predetermined time. In this configuration, when one of the voltage conversion units CV is switched from the operation state to the stop state by the operation stop control, if the switching target is normal, the output of the multiphase conversion unit 2 is appropriately set before and after the switching. If the switching target is abnormal (for example, switching element open abnormality, etc.), the output of the polyphase converter 2 will show an abnormal change before and after switching. Using such a feature, the control circuit 10 corresponding to the specific unit is a voltage at which an abnormality has occurred based on a change in the output current from the polyphase conversion unit 2 during the period in which the control unit 4 performs the operation stop control. The conversion unit CV is specified. Therefore, according to this structure, the abnormal part of the power supply device 1 which can perform voltage conversion by the several voltage conversion part CV can be specified concretely.

  The control unit 4 is configured to perform operation stop control when a stop condition for stopping the operation of the vehicle is satisfied (specifically, when an ignition on signal indicating that the ignition switch is turned on is input). It is. According to this configuration, the operation stop control (control that gradually increases the number of voltage conversion units CV that stop the operation) can be performed at the time when the operation of the vehicle is stopped (that is, when the vehicle does not travel). Therefore, the stop operation for specifically specifying the abnormal part can be performed while suppressing the influence on the vehicle operation.

  When the voltage conversion unit CV in which an abnormality has occurred is specified by the specifying unit when the operation stop control is performed according to the establishment of the stop condition, the control unit 4 performs the previous operation when the next vehicle start condition is satisfied. The voltage converter CV identified as abnormal in the stop control is selectively operated. Then, the control circuit 10 functions as a protection operation unit, and selectively based on the output current from the polyphase conversion unit 2 when the voltage conversion unit CV is selectively operated when the next vehicle start condition is satisfied. It is determined whether or not the operated voltage conversion unit CV is abnormal, and when it is abnormal, a predetermined protection operation is performed.

  According to this configuration, when the abnormality detection is performed at the time when the vehicle is stopped, when the voltage conversion unit CV as the abnormal part is specified, whether or not the specified part is abnormal is determined again at the start time. Can be confirmed. By such a method, it is possible to determine abnormality with high certainty. In addition, since the abnormality determination is performed a plurality of times at the time when the vehicle operation is stopped and the next start time, the operation stop control and the abnormality re-determination are less likely to affect the vehicle operation such as traveling.

  The control unit 4 controls all the voltage conversion units CV so that the output current from the multiphase conversion unit 2 becomes the first target value at the time of normal control for operating all the voltage conversion units CV (during steady state control). The structure which controls the drive of is made. On the other hand, when any one of the voltage converters CV is selectively operated in the re-determination control of FIG. 3 executed when the next vehicle start condition is established after the abnormality determination control of FIG. The driving of the selected voltage converter CV is controlled so that the current becomes a second target value smaller than the first target value. When a part with high possibility of abnormality is selectively operated and re-determined, an excessive output different from the normal may occur.Therefore, re-determination is performed by operation with the target value suppressed as in the above configuration. For example, an excessive output at the time of redetermination is easily suppressed.

  In the control circuit 10 corresponding to the specific unit, the fluctuation amount of the output current before and after switching when any of the voltage conversion units CV is switched from the operating state to the stopped state during the period in which the control unit 4 performs the operation stop control. When the voltage conversion unit CV is equal to or less than a predetermined value, the voltage conversion unit CV (the voltage conversion unit CV that has been switched so that the fluctuation amount is equal to or less than the predetermined value) is determined to be abnormal.

  This effect will be described with reference to FIG. In the example of FIG. 4, an open failure has occurred in the switch element of the second phase (voltage converter CV) among the m voltage converters CV to be driven, and an abnormality in which no current flows in the second phase has occurred. This is an example. In FIG. 4, the horizontal axis is time, the vertical axis is output current, and the time 0 is the timing when switching from steady state control to operation stop control. Then, after time 0, the first phase (voltage converter CV) of the drive number m is stopped at time T1, and the second phase (voltage converter CV) of the drive number m is stopped at time T2. And the m-th phase (voltage converter CV) of the drive number m is stopped at time Tm.

  In this configuration, the target current value in the steady state and during the operation stop control in FIG. 2 is X1, and when operating the m voltage converters CV, the current value of each phase is controlled to X1 / m. The When the above-described operation stop control is performed on the polyphase converter 2 in which all the voltage converters CV are in the normal state, the voltage converter CV flows to the stopped voltage converter CV every time the operation of the voltage converter CV stops. Current fluctuation (current drop) corresponding to the current occurs, and thereafter, the output current value is returned to the target current value X1 by feedback control on the remaining voltage conversion unit CV. However, when an open failure has occurred in the switch element of the second phase (voltage conversion unit CV) as shown in FIG. 4 and no current flows in the second phase, a normal 1 is obtained at time T1. When the operation of the second phase (voltage conversion unit CV) is stopped, current fluctuation occurs, but when the operation of the second phase (voltage conversion unit CV) in which an open failure occurs is stopped, current fluctuation occurs before and after the stop. Therefore, the current fluctuation amount is equal to or less than a predetermined value (for example, a predetermined value set larger than 0 and smaller than X1 / m). In the abnormality determination control shown in FIG. 2, such an abnormality can be specified by the processes in steps S7 to S9. If abnormality determination is performed by such a method, it is possible to more accurately identify an abnormal portion where sufficient output is not made.

  The control circuit 10 corresponding to the specific unit is configured such that, during the period in which the control unit 4 performs the operation stop control, when any voltage conversion unit CV is switched from the operation state to the stop state, the output current is set to a predetermined output threshold value ( It is a predetermined threshold value that is larger than 0 and smaller than the target current value X1, for example, a value that exceeds X1 / m or less), and changes to a state that is equal to or less than a predetermined output threshold value and is not switched to a stopped state after the change. When the remaining voltage converter CV exists, the remaining voltage converter CV existing after the change is determined to be abnormal.

  This effect will be described with reference to FIG. In the example of FIG. 5, an open failure has occurred in the switch element of the m-th phase (voltage conversion unit CV) among the m voltage conversion units CV to be driven, and an abnormality in which no current flows in the m-th phase has occurred. This is an example. In this configuration, when the times T1, T2, T3... And the voltage conversion unit CV are sequentially stopped, voltage fluctuation occurs at each stop timing, and after each stop timing, the output current is again set to the target current value. Control is performed to return to X1. However, when an open failure has occurred in the switch element of the m-th phase (voltage conversion unit CV) as shown in FIG. 5 and no current flows in the m-th phase, m at time Tm−1. When the operation of the −1st phase (voltage conversion unit CV) is stopped, the current decreases to 0. In the abnormality determination control shown in FIG. 2, such an abnormality can be specified by the processes in steps S <b> 3 to S <b> 6. If abnormality determination is performed by such a method, it is possible to more accurately identify an abnormality portion where sufficient output is not performed, and it is possible to end abnormality determination for all voltage conversion units CV earlier. .

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

(1) In the first embodiment, the step-down type multi-phase converter is exemplified, but it may be a step-up type multi-phase converter or a step-up / step-down type multi-phase converter. In any case, the operation of the voltage conversion unit is stopped one phase at a time or a plurality of phases at a predetermined time, and when the amount of fluctuation in the output current becomes less than a predetermined value before or after any stop, it becomes the target of the stop. In addition, it is possible to use a method in which one or more voltage conversion units are determined to be abnormal.
(2) In the first embodiment, k is a natural number of 1 to n, and the switch element SBk is provided on the low side of each phase. However, it can be replaced with a diode whose anode is connected to the ground potential. The switch elements SAk and SBk may be P-channel MOSFETs or other switch elements such as bipolar transistors.
(3) The primary-side power supply unit 91 and the secondary-side power supply unit 92 in Example 1 are merely examples, and various known power storage units can be applied.
(4) The output configuration on the input side and output side in the first embodiment is merely an example, and in any example, various devices and electronic components can be connected to the input side conductive path 6 and the output side conductive path 7. it can.
(5) In FIG. 1, the power supply device 1 having a four-phase structure in which four voltage conversion units CV1, CV2, CV3, and CV4 are connected in parallel is illustrated as a representative example. However, the number of voltage conversion units is less than four. It may be 5 or more.
(6) The control unit 4 sets the output voltage to the target voltage value based on the voltage value (detected voltage value) of the output-side conductive path 7 input to the control circuit 10 and the target value (target voltage value) of the output voltage. The feedback calculation by a known PID control method may be performed so as to be close to, and the control amount (duty ratio) to be given to each voltage converter CV may be determined.
(7) In the first embodiment, the example in which the operation stop control is performed when the ignition switch is turned off has been described. However, any example is not limited to this example. For example, the operation stop control may be performed at a predetermined time during engine operation. Alternatively, the operation stop control may be performed immediately after the engine is started.
(8) In the first embodiment, in the operation stop control, the example in which the number of the voltage conversion units CV for stopping the operation is increased one by one. However, a plurality of voltage conversion units CV for stopping the operation (for example, You may make it increase by 2). Also in this case, the abnormality can be determined by the same method as in the first embodiment. For example, in the period when the control unit 4 performs the operation stop control, when the fluctuation amount of the output current is equal to or less than a predetermined value before and after switching when any two voltage conversion units CV are switched from the operation state to the stop state. The two voltage converters CV may be determined as abnormal. In this case, in the redetermination control of FIG. 3, the two voltage converters CV determined to be abnormal are operated, and when the output current value is equal to or less than a certain value, the two voltage converters CV are determined to be abnormal and constant. When the value is exceeded, both of the two voltage conversion units CV may be determined to be normal. Further, in this configuration, when the control unit 4 performs the operation stop control, any two voltage conversion units CV are switched from the operation state to the stop state, so that the output current exceeds the predetermined output threshold value. When there is a residual voltage conversion unit that changes from a current state to a state below a predetermined output threshold and is not switched to a stopped state after the change, the remaining voltage conversion unit that exists after the change may be determined to be abnormal.
(9) The control circuit 10 corresponding to the specific unit is before and after switching when any one or a plurality of voltage conversion units CV are switched from the operating state to the stopped state during the period in which the control unit 4 performs the operation stop control. When the variation amount of the output voltage is equal to or less than a predetermined value, the voltage conversion unit (one or more voltage conversion units CV that have been switched so that the variation amount is equal to or less than the predetermined value) may be determined to be abnormal.

(10) The control circuit 10 corresponding to the specific unit outputs the output voltage when one or more of the voltage conversion units CV are switched from the operation state to the stop state during the period in which the control unit 4 performs the operation stop control. Is changed from a state exceeding a predetermined output threshold to a state equal to or lower than a predetermined output threshold, and when there is a residual voltage converter that has not been switched to a stopped state after the change, a residual voltage converter present after the change May be determined as abnormal.

DESCRIPTION OF SYMBOLS 1 ... Power supply device 2 ... Polyphase conversion part 3 ... Abnormality detection apparatus 4 ... Control part 10 ... Control circuit (specific part, protection operation | movement part)
CV: Voltage converter SA1, SA2, SA3, SA4, SB1, SB2, SB3, SB4 ... Switch element

Claims (7)

Each of the switch elements provided in each of the voltage conversion units of the multiphase conversion unit is controlled by a multiphase conversion unit including a plurality of voltage conversion units that step up or down an input voltage by an on / off operation of the switch element. The operation stop control is configured to output a control signal that alternately switches between an on signal and an off signal, and to gradually increase the number of the voltage conversion units that stop the operation of the polyphase conversion unit at a predetermined time. A control unit for performing
Based on a change in at least one of an output current and an output voltage from the multiphase converter during a period in which the control unit performs the operation stop control, the one or more voltage converters in which an abnormality has occurred are identified. A specific part,
An abnormality detection device including:   The abnormality detection device according to claim 1, wherein the control unit performs the operation stop control when a stop condition for stopping the operation of the vehicle is satisfied. When one or more of the voltage converters that are abnormal are specified by the specifying unit when the operation stop control is performed according to the establishment of the stop condition, the control unit determines that the next vehicle start condition At the time of establishment, selectively operating one or more of the voltage converters identified as abnormal by the specific unit in the previous operation stop control,
Further, based on at least one of the output current or the output voltage from the multiphase converter when the one or more voltage converters are selectively operated when the next vehicle start condition is satisfied, The abnormality detection device according to claim 2, further comprising: a protection operation unit that determines whether or not one or more of the voltage conversion units that are operated in an abnormal state is abnormal, and performs a predetermined protective operation when the voltage conversion unit is abnormal. The controller is
At the time of normal control for operating all the voltage conversion units, the drive of all the voltage conversion units is controlled so that the output current or output voltage from the multiphase conversion unit becomes the first target value,
When selectively operating one or a plurality of the voltage converters when the next vehicle start condition is satisfied, the output current or the output voltage is selected to be a second target value smaller than the first target value. The abnormality detection device according to claim 3, wherein the driving of one or a plurality of the voltage conversion units is controlled.   The specifying unit includes the output current or the output voltage before and after switching when any one or a plurality of the voltage conversion units are switched from the operating state to the stopped state during the period in which the control unit performs the operation stop control. 5. The one or more of the voltage conversion units that have been switched so that the fluctuation amount is equal to or less than the predetermined value when the fluctuation amount is less than or equal to the predetermined value are determined to be abnormal. The abnormality detection device described in 1.   In the period when the control unit performs the operation stop control, the specifying unit is configured so that the output current or the output voltage is predetermined when one or more of the voltage conversion units are switched from the operation state to the stop state. If there is a residual voltage converter that has changed from a state exceeding the output threshold to a state equal to or lower than the predetermined output threshold and has not been switched to the stopped state after the change, the residual voltage converter that exists after the change The abnormality detection device according to any one of claims 1 to 5, wherein the abnormality is determined to be abnormal.   The power supply device containing the abnormality detection apparatus as described in any one of Claims 1-6, and the said polyphase conversion part.

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