Boost Converter Device

Abstract

For each of the current detectors, when the preliminary determination of the abnormality continues for a determination time, the abnormality is determined. In this case, the determination time is set such that: when the absolute value of the detection value of the current detector that has not been preliminarily determined to be abnormal is larger, the determination time is shorter; or when the absolute value of the target current of the reactor corresponding to the current detector that has not been preliminarily determined to be abnormal is larger, the determination time is shorter; or when the absolute value of the estimated current of the reactor corresponding to the current detector that has been preliminarily determined to be abnormal, which is estimated based on the current of any one of the power storage device and the load and the detection value of the current detector that has not been preliminarily determined to be abnormal, is larger, the determination time is shorter.

Description

Technical Field

[0001] The invention relates to a boost converter arrangement. Background Art

[0002] In the past, as such a boost converter device, a boost converter device including a first boost converter and a second boost converter has been proposed, wherein the first boost converter and the second boost converter are connected in parallel with each other relative to a battery and a motor, and each has an upper arm, a lower arm, and a reactor, and each can boost the power on the battery side and supply it to the motor side (for example, refer to Patent Document 1). In the above-mentioned boost converter device, when the current of the battery is a positive value, the current of the reactor of the first boost converter is a positive value, and the current of the reactor of the second boost converter is a negative value, the on-fault of the upper arm of the second boost converter is judged. In addition, when the current of the battery is a positive value, the current of the reactor of the second boost converter is a positive value, and the current of the reactor of the first boost converter is a negative value, the on-fault of the upper arm of the first boost converter is judged.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-103876 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] In the above-mentioned boost converter device, although the on-failure of the first boost converter and the second boost converter can be detected, the abnormality detection method of the first current detector and the second current detector for detecting the current of the reactor of the first boost converter and the second boost converter is not recorded. Once an abnormality occurs in the first current detector and the second current detector, the first boost converter and the second boost converter cannot be properly controlled, and the absolute value of the actual current of the reactor of the first boost converter and the second boost converter may become too large due to excessive current reflux (Japanese: current return flow) between the first boost converter and the second boost converter. Based on this, in a boost converter device including a plurality of boost converters connected in parallel with respect to a storage device such as a battery and a load such as a motor, it is required to design a method that can properly detect the abnormality of each of the plurality of current detectors for detecting the current of each reactor.

[0008] An object of the boost converter device of the present invention is to devise a method capable of appropriately detecting an abnormality of each current detector.

[0009] The boost converter device of the present invention adopts the following means to achieve the above-mentioned main object.

[0010] The core of the boost converter device of the present invention is that the boost converter device comprises:

[0011] a plurality of boost converters, each of which is connected in parallel with respect to the power storage device and the load, and each of which has an upper arm, a lower arm, and a reactor, and each of which can boost the power on the power storage device side and supply it to the load side;

[0012] a plurality of current detectors, the plurality of current detectors detecting currents of the respective reactors; and

[0013] A control device controls each of the boost converters in such a manner as to eliminate a difference between a target current of the corresponding reactor and a detection value of the corresponding current detector, wherein:

[0014] The control device determines that the abnormality is caused when the preliminary determination of the abnormality continues for a predetermined time for each of the current detectors.

[0015] The determined time is set to:

[0016] The determination time is shortened as the absolute value of the detection value of the current detector that is not preliminarily determined to be abnormal is larger; or,

[0017] The determination time is shortened as the absolute value of the target current of the reactor corresponding to the current detector that is not preliminarily determined to be abnormal is larger; or,

[0018] The determination time is shorter when the absolute value of the estimated current of the reactor corresponding to the current detector preliminarily determined to be abnormal, which is estimated based on the current of any one of the power storage device and the load and the detection value of the current detector not preliminarily determined to be abnormal, is larger.

[0019] In the boost converter device of the present invention, the control device determines the abnormality for each current detector when the preliminary determination of the abnormality continues for a certain time. In this case, the determination time is set to: when the absolute value of the detection value of the current detector that has not been preliminarily determined to be abnormal is larger, the determination time is shorter; or when the absolute value of the target current of the reactor corresponding to the current detector that has not been preliminarily determined to be abnormal is larger, the determination time is shorter; or when the absolute value of the estimated current of the reactor corresponding to the current detector that has been preliminarily determined to be abnormal, which is estimated based on the current of any one of the storage device and the load and the detection value of the current detector that has not been preliminarily determined to be abnormal, is larger, the determination time is shorter. It can be imagined that when the absolute value of the detection value of the current detector that has not been preliminarily determined to be abnormal, the absolute value of the target current of the reactor corresponding to the current detector that has not been preliminarily determined to be abnormal, and the absolute value of the estimated current of the reactor corresponding to the current detector that has been preliminarily determined to be abnormal are larger, the absolute value of the actual current of each reactor L2 is likely to become too large due to excessive current reflux between multiple boost converters. Therefore, by setting the determination time according to the above trend, the absolute value of the current of each reactor can be prevented from becoming too large or the excessive state can be prevented from continuing, and the abnormality of each current detector can be properly detected (determined). Here, the "upper arm" and the "lower arm" are configured in such a way that the switching element and the diode are connected in parallel with each other.

[0020] In the boost converter device of the present invention, each of the current detectors may include a first current sensor and a second current sensor for detecting the current of the corresponding reactor, and the control device may preliminarily determine that each of the current detectors is abnormal when the difference between the detection value of the first current sensor and the detection value of the second current sensor is greater than a threshold value. By means of the above, it is possible to preliminarily determine that each of the current detectors is abnormal.

[0021] In this case, each of the current detectors may set the detection value of the first current sensor as the detection value of the current detector. At this time, when the abnormality of the first current sensor is determined as a preliminary abnormality of the current detector, the determination time is sometimes set to a relatively short time, considering that the absolute value of the actual current of each reactor may become too large due to the excessive current reflux between the plurality of boost converters when the boost converter corresponding to the current detector cannot be properly controlled. In contrast, when the abnormality of the second current sensor is determined as a preliminary abnormality of the current detector, the determination time is set to a relatively long time because the boost converter corresponding to the current detector can be properly controlled.

[0022] In the boost converter device of the present invention, the control device may also set a target supply current to be supplied from the power storage device side to the load side via a plurality of the boost converters in a manner that eliminates a difference between the target supply voltage and the supply voltage of the load, and sets the target current of each of the reactors based on the target supply current.

[0023] In the boost converter device of the present invention, the control device may stop driving all of the multiple boost converters or stop driving only the boost converter corresponding to the current detector in which the abnormality is determined when the abnormality is determined in one of the multiple current detectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is a schematic structural diagram showing an electric vehicle 20 equipped with a boost converter device as one embodiment of the present invention.

[0025] Figure 2 This is a flowchart of an example of an abnormality detection routine executed by the ECU 50 .

[0026] Figure 3 This is an explanatory diagram showing an example of a map for finalizing time setting.

[0027] Figure 4 It is an explanatory diagram schematically showing a state when an abnormality occurs in the current sensor 41 a of the first current detector 41 . DETAILED DESCRIPTION

[0028] Next, the mode for carrying out the present invention will be described using examples.

[0029] Figure 1 FIG. 2 is a schematic structural diagram showing the structure of an electric vehicle 20 equipped with a boost converter device as one embodiment of the present invention. Figure 1 As shown, the electric vehicle 20 of the embodiment includes: a motor 22 ; an inverter 24 ; a battery 26 as an electric storage device; a first boost converter 40 and a second boost converter 42 ; and an electronic control unit (hereinafter, referred to as “ECU”) 50 .

[0030] The motor 22 is configured as a synchronous generator motor, for example. Although not shown in the figure, the rotor of the motor 22 is connected to a drive shaft connected to the drive wheel via a differential gear. The inverter 24 is connected to the motor 22 and to the high-voltage side power line 32. The ECU 50 controls the switching of a plurality of switching elements (not shown) of the inverter 24 to drive the motor 22 to rotate. A capacitor 33 for smoothing is installed on the positive side line and the negative side line of the high-voltage side power line 32.

[0031] The battery 26 is configured as, for example, a lithium ion secondary battery or a nickel-metal hydride secondary battery, and is connected to the low voltage power line 34. On the positive and negative poles of the low voltage power line 34, capacitors 35 for smoothing are mounted.

[0032] The first boost converter 40 is connected to the high-voltage side power line 32 and the low-voltage side power line 34, and is configured as a known boost-boost converter having two transistors T11 and T12, two diodes D11 and D12, and a reactor L1. The transistor T11 is connected to the positive line of the high-voltage side power line 32. The transistor T12 is connected to the transistor T11 and the negative line of the high-voltage side power line 32 and the low-voltage side power line 34. The reactor L1 is connected to the connection point between the transistors T11 and T12 and the positive line of the low-voltage side power line 34. By adjusting the ratio of the on-time of the transistors T11 and T12 by the ECU 50, the first boost converter 40 boosts the power of the low-voltage side power line 34 and supplies it to the high-voltage side power line 32, or steps down the power of the high-voltage side power line 32 and supplies it to the low-voltage side power line 34.

[0033] The second boost converter 42 is connected in parallel with the first boost converter 40 with respect to the high-voltage side power line 32 (inverter 24 side) and the low-voltage side power line 34 (battery 26 side). Similar to the first boost converter 40, the second boost converter 42 is connected to the high-voltage side power line 32 and the low-voltage side power line 34, and is configured as a known boost-down converter having two transistors T21, T22, two diodes D21, D22 and a reactor L2. By adjusting the ratio of the on-time of the transistors T21, T22 by the ECU 50, the second boost converter 42 boosts the power of the low-voltage side power line 34 and supplies it to the high-voltage side power line 32, or steps down the power of the high-voltage side power line 32 and supplies it to the low-voltage side power line 34.

[0034] Although not shown in the figure, the ECU 50 is configured as a microprocessor centered around a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, and an input / output port in addition to the CPU.

[0035] Signals from various sensors are input to the ECU 50 via the input port. As the signals input to the ECU 50, for example, the rotational position θm of the rotor of the motor 22 and the phase currents Iu and Iv of the respective phases of the motor 22 can be listed, wherein the rotational position θm of the rotor of the motor 22 is from a rotational position sensor (not shown) that detects the rotational position of the rotor of the motor 22, and the phase currents Iu and Iv of the respective phases of the motor 22 are from current sensors (not shown) that detect the current flowing in the respective phases of the motor 22. In addition, the voltage Vb of the battery 26 and the current Ib of the battery 26 can also be listed, wherein the voltage Vb of the battery 26 is from a voltage sensor 26a installed between the terminals of the battery 26, and the current Ib of the battery 26 is from a current sensor 26b installed at the output terminal of the battery 26. In addition, the voltage VH of the high-voltage power line 32 (capacitor 33) and the voltage VL of the low-voltage power line 34 (capacitor 35) can be cited, wherein the voltage VH of the high-voltage power line 32 (capacitor 33) comes from a voltage sensor 33a installed between the terminals of the capacitor 33, and the voltage VL of the low-voltage power line 34 (capacitor 35) comes from a voltage sensor 35a installed between the terminals of the capacitor 35. In addition, the currents IL1a and IL1b of the reactor L1 and the currents IL2a and IL2b of the reactor L2 can be cited, wherein the currents IL1a and IL1b of the reactor L1 come from current sensors 41a and 41b of the first current detector 41 that detects the current flowing in the reactor L1 of the first boost converter 40, and the currents IL2a and IL2b of the reactor L2 come from current sensors 43a and 43b of the second current detector 43 that detects the current flowing in the reactor L2 of the second boost converter 42. In addition, although not shown in the figure, the ignition signal from the ignition switch, the shift position SP from the shift position sensor that detects the operating position of the shift lever, the accelerator opening Acc from the accelerator pedal position sensor that detects the amount of accelerator pedal depression, the brake pedal position BP from the brake pedal position sensor that detects the amount of brake pedal depression, and the vehicle speed V from the vehicle speed sensor can also be listed.

[0036] Various control signals are outputted from the ECU 50 via the output port. Examples of the signals outputted from the ECU 50 include switching control signals for the plurality of switching elements of the inverter 24, switching signals for the transistors T11 and T12 of the first boost converter 40, and switching control signals for the transistors T21 and T22 of the second boost converter 42.

[0037] The ECU 50 calculates the electrical angle θe and the number of revolutions Nm of the motor 22 based on the rotational position θm of the rotor of the motor 22. In addition, the ECU 50 calculates the power storage ratio SOC of the battery 26 based on the integrated value of the current Ib of the battery 26. Here, the power storage ratio SOC is the ratio of the capacity of the electric power that can be discharged from the battery 26 to the full capacity of the battery 26.

[0038] In the present embodiment, the first boost converter 40, the second boost converter 42, the first current detector 41 (current sensors 41a, 41b), the second current detector 43 (current sensors 43a, 43b), and the ECU 50 belong to the "boost converter device". In addition, regarding each "boost converter", the transistor T11 and the diode D11, the transistor T21 and the diode D21 correspond to the "upper arm", and the transistor T12 and the diode D12, the transistor T22 and the diode D22 correspond to the "lower arm".

[0039] In the electric vehicle 20 of the embodiment constructed as above, as driving control, the control of the motor 22 and the first boost converter 40 and the second boost converter 42 is performed, for example, in the following manner. Regarding the control of the motor 22, the ECU 50 initially sets the required torque Td* required for driving (required by the drive shaft) based on the accelerator opening Acc from the accelerator pedal position sensor and the vehicle speed V from the vehicle speed sensor. Then, the torque command Tm* of the motor is set in such a way that the set required torque Td* is output to the drive shaft. Then, the switching control of the plurality of switching elements of the inverter 24 is performed in such a way that the motor 22 is driven by the torque command Tm*.

[0040] Regarding the first boost converter 40 and the second boost converter 42, the ECU 50 initially sets the voltage command (target voltage) VH* of the high-voltage side power line 32 based on the torque command Tm* of the motor 22. Next, the ECU 50 sets the supply current command (target supply current) IL* to be supplied from the low-voltage side power line 34 (battery 26 side) to the high-voltage side power line 32 (inverter 24 side) via the first boost converter 40 and the second boost converter 42 in such a manner as to eliminate the difference between the voltage VH of the high-voltage side power line 32 from the voltage sensor 33a and the voltage command VH* (through voltage feedback control). Next, the supply current command IL* is multiplied by the distribution ratios D1 and D2 of the first boost converter 40 and the second boost converter 42 to calculate the current commands (target currents) IL1* and IL2* of the reactors L1 and L2. Here, the sum of the distribution ratios D1 and D2 is 1, and as the distribution ratio D1, for example, 0.5 is used.

[0041] Next, the duty cycle commands Du1* and Du2* of the first boost converter 40 and the second boost converter 42 are set so as to eliminate the difference between the currents IL1a and IL2a of the reactors L1 and L2 from the current sensors 41a and 43a and the current commands IL1* and IL2* (through current feedback control). Next, the switching control of the transistors T11, T12, T21 and T22 of the first boost converter 40 and the second boost converter 42 is performed using the duty cycle commands Du1* and Du2*.

[0042] Next, the operation of the boost converter device mounted on the electric vehicle 20 according to the embodiment configured as above, particularly the abnormality detection process of the first current detector 41, will be described. Figure 2 4 is a flowchart of an example of an abnormality detection routine executed by the ECU 50. When the abnormality of the first current detector 41 is not detected (confirmed), the above routine is repeatedly executed.

[0043] When executing Figure 2 When performing the abnormality detection routine, the ECU 50 initially inputs the currents IL1a and IL1b of the reactor L1 from the current sensors 41a and 41b of the first current detector 41 (step S100), and calculates the current difference ΔIL1 as the difference between the currents IL1a and IL1b of the input reactor L1 (the absolute value of the value obtained by subtracting IL1b from the current IL1a) (step S110).

[0044] Next, the ECU 50 compares the current difference ΔIL1 with the threshold ΔIL1ref (step S120). Here, the threshold ΔIL1ref is a threshold for determining whether an abnormality occurs in the first current detector 41 (either one of the current sensors 41a and 41b), and is set after taking into account the manufacturing error of the current sensors 41a and 41b. When the current difference ΔIL1 is less than the threshold ΔIL1ref, the ECU 50 determines that the first current detector 41 is normal, that is, either one of the current sensors 41a and 41b is normal (step S130), and ends this routine.

[0045] When the current difference ΔIL1 is greater than the threshold value ΔIL1ref in step S120, the ECU 50 preliminarily determines that the first current detector 41 is abnormal, that is, the current sensors 41a and 41b are abnormal (step S140), and compares the last current difference (previous ΔIL1) with the threshold value ΔIL1ref (step S150). This process is a process for determining whether the first current detector 41 is abnormal after the preliminary determination is made.

[0046] In step S150, when the last current difference (last ΔIL1) is less than the threshold value ΔIL1ref, the ECU 50 determines that the preliminary determination of the abnormality of the first current detector 41 has just started, resets the duration Tt of the preliminary determination to 0, and then starts counting (step S160). On the other hand, when the last current difference (last ΔIL1) is greater than the threshold value ΔIL1ref, the ECU 50 determines that the preliminary determination of the abnormality of the first current detector 41 has not just started (the preliminary determination is continuing), and does not execute the processing of step S160.

[0047] Next, the ECU 50 inputs the current IL2a of the reactor L2 from the current sensor 43a (step S170), and uses the absolute value of the input current IL2a of the reactor L2 and the determination time setting map to set the determination time Tc for determining the abnormality of the first current detector 41 (step S180). Here, the determination time setting map is pre-set as the relationship between the current IL2a of the reactor L2 and the determination time Tc, and is stored in a ROM (not shown). Figure 3 1 is an explanatory diagram showing an example of a map for setting the determination time. As shown in the figure, the determination time Tc is set so that the determination time Tc becomes shorter as the absolute value of the current IL2a of the reactor L2 increases. The reason for this will be described later.

[0048] Next, the ECU 50 compares the duration Tt of the preliminary determination of the abnormality of the first current detector 41 with the determination time Tc (step S190). When the duration Tt of the preliminary determination of the abnormality of the first current detector 41 is less than the determination time Tc, the abnormality of the first current detector 41 is not determined and the process returns to step S100. The processes of steps S100 to S120 and S140 to S190 are repeatedly performed. When the duration Tt of the preliminary determination of the abnormality of the first current detector 41 reaches or exceeds the determination time Tc in step S190, the abnormality of the first current detector 41 is detected (determined), and the routine ends. Once the abnormality of the first current detector 41 is detected (determined), the driving of the first boost converter 40 and the second boost converter 42 is stopped. In addition, even if the first boost converter 40 and the second boost converter 42 stop driving, when the voltage VH of the high-voltage side power line 32 reaches below the voltage VL of the low-voltage side power line 34, current (power) will be supplied from the battery 26 side to the inverter 24 side via the diodes D11 and D21 of the first boost converter 40 and the second boost converter 42 for driving the motor 22.

[0049] Here, for example Figure 3 The reason for setting the determination time Tc is described below. Figure 41 is an explanatory diagram schematically showing the voltage command VH* and voltage VH of the high-voltage side power line 32, the current command IL1*, actual current IL1act and current IL1a of the reactor L1, and the current command IL2*, actual current IL2act and current IL2a of the reactor L2 when an abnormality occurs in the current sensor 41a of the first current detector 41. In the figure, the voltage VH is the detection value of the voltage sensor 33a, and the currents IL1a and IL2a are the detection values ​​of the current sensors 41a and 43a. Figure 4 , a case is shown in which the second current detector 43 is normal, that is, the actual current IL2act of the reactor L2 is detected as the current IL2a by the current sensor 43a.

[0050] As shown in the figure, when the current sensor 41a is abnormal and the current IL1a of the reactor L1 becomes very large relative to the current command IL1* (time T1), the first boost converter 40 is controlled to reduce the actual current IL1act of the reactor L1. In this way, as the actual current IL1act of the reactor L1 decreases, the voltage VH of the high-voltage side power line 32 decreases relative to the voltage command VH*, and the supply current command IL*, and then the current commands IL1* and IL2* of the reactors L1 and L2 increase. As a result, the second boost converter 42 is controlled to increase the actual current IL2act of the reactor L2, so that the actual current IL2act and the current IL2a increase. In addition, in order to make the current command IL1* of the reactor L1 still smaller than the current IL1a, the first boost converter 40 is controlled to further reduce the actual current IL1act of the reactor L1, so that the actual current IL1act further decreases. The deviation between the actual current IL1act of the reactor L1 and the actual current IL2act of the reactor L2 causes a current backflow between the first boost converter 40 and the second boost converter 42. In addition, it is conceivable that when the absolute value of the current IL2act of the reactor L2 is larger, the absolute values ​​of the actual current IL1act of the reactor L1 and the actual current IL2act of the reactor L2 are likely to become too large with an excessive current backflow between the first boost converter 40 and the second boost converter 42. In view of this, in the embodiment, as Figure 3 As shown in FIG. 1 , the determination time Tc is set so that the greater the absolute value of the current IL2a of the reactor L2 detected by the current sensor 43a, the shorter the determination time Tc becomes. Thus, the absolute values ​​of the actual current IL1act of the reactor L1 and the actual current IL2act of the reactor L2 can be prevented from becoming excessive or from continuing in an excessive state, and the abnormality of the first current detector 41 can be properly detected (determined).

[0051] In addition, the first current detector 41 is initially determined to be abnormal when the current sensor 41a is abnormal and when the current sensor 41b is abnormal. Here, the current IL1a of the reactor L1 detected by the current sensor 41a is used to control the first boost converter 40, and the current sensor 41b is used to determine whether the current sensor 41a is normal. Therefore, when the current sensor 41a is abnormal, as described above, when the first boost converter 40 cannot be properly controlled, the absolute values ​​of the actual current IL1act of the reactor L1 and the actual current IL2act of the reactor L2 may become too large due to the excessive current circulation between the first boost converter 40 and the second boost converter 42, and sometimes the determination time Tc is set to a relatively short time. In contrast, when the current sensor 41b is abnormal, since the first boost converter 40 can be properly controlled, the determination time Tc is set to a relatively long time.

[0052] In the boost converter device installed in the electric vehicle 20 of the embodiment described above, when the current difference ΔIL1, which is the difference between the currents IL1a and IL1b of the reactor L1 from the current sensors 41a and 41b of the first current detector 41, is greater than the threshold value ΔIL1ref, the abnormality of the first current detector 41 is preliminarily determined, and when the duration Tt of the preliminary determination of the abnormality of the first current detector 41 is longer than the determination time Tc, the abnormality of the first current detector 41 is determined. In this case, the determination time Tc is set so that the determination time Tc becomes shorter as the absolute value of the current IL2a of the reactor L2 is larger. Thus, the abnormality of the first current detector 41 can be appropriately detected (determined).

[0053] In addition, in the embodiment, the use Figure 2 The abnormality detection routine of the present invention will be described with respect to the abnormality detection processing of the first current detector 41, but the abnormality detection processing of the second current detector 43 can also be performed in the same manner.

[0054] In the boost converter device installed in the electric vehicle 20 of the embodiment, the ECU 50 sets the determination time Tc based on the absolute value of the current IL2a of the reactor L2 when the first current detector 41 is preliminarily determined to be abnormal. However, the ECU 50 may also set the determination time Tc based on the absolute value of the current command IL2* of the reactor L2 when the first current detector 41 is preliminarily determined to be abnormal. In this case, for example, Figure 3The horizontal axis of the determination time setting map is replaced from "the absolute value of the current IL2a of the reactor L2" to "the absolute value of the current command IL2* of the reactor L2". The second boost converter 42 is controlled in such a way that the difference between the current IL2a of the reactor L2 from the current sensor 43a and the current command IL2* is eliminated. Therefore, even when the absolute value of the current command IL2* of the reactor L2 is used, the same effect as in the embodiment can be exerted. In addition, the same consideration can be applied when the abnormality of the second current detector 43 is preliminarily determined.

[0055] In the boost converter device installed in the electric vehicle 20 of the embodiment, when the ECU 50 preliminarily determines that the first current detector 41 is abnormal, the determination time Tc is set to be shorter as the absolute value of the current IL2a of the reactor L2 is larger. However, when the ECU 50 preliminarily determines that the first current detector 41 is abnormal, the ECU 50 may calculate the estimated current IL1es of the reactor L1 by subtracting the current IL2a of the reactor L2 from the current sensor 43a from the current Ib of the battery 26 from the current sensor 26b, and set the determination time Tc based on the estimated current IL1es of the reactor L1. In this case, for example, Figure 3 The horizontal axis of the determination time setting map is replaced from the "absolute value of the current IL2a of the reactor L2" to the "absolute value of the estimated current IL1es of the reactor L1". Figure 4 As shown in FIG. 1 , the greater the absolute value of the current IL2a (actual current IL2act) of the reactor L2 detected by the current sensor 43a, the greater the absolute value of the actual current IL1act of the reactor L1. Therefore, even when the absolute value of the estimated current IL1es of the reactor L1 is used, the same effect as in the embodiment can be exerted. In addition, when the abnormality of the second current detector 43 is preliminarily determined, the same consideration can be applied.

[0056] In the boost converter device installed in the electric vehicle 20 of the embodiment, when the ECU 50 detects (determines) the abnormality of the first current detector 41, the first boost converter 40 and the second boost converter 42 are stopped from driving. However, when the ECU 50 detects (determines) the abnormality of the first current detector 41, only the first boost converter 40 is stopped from driving, that is, the driving of the second boost converter 42 is continued. In this way, even if the abnormality of the first current detector 41 is detected, the voltage VH of the high-voltage side power line 32 can be made higher than the voltage VL of the low-voltage side power line 34. At this time, the transistor T11 of the first boost converter 40 is turned off, so the current does not flow from the high-voltage side power line 32 to the low-voltage side power line 34 through the transistor T11. Therefore, the current does not flow back between the first boost converter 40 and the second boost converter 42. In addition, when the abnormality of the second current detector 43 is detected (determined), it can be considered in the same way.

[0057] The boost converter device installed in the electric vehicle 20 of the embodiment includes a first boost converter 40 and a second boost converter 42 connected in parallel with each other on the battery 26 side and the inverter 24 side. However, three or more boost converters connected in parallel with each other on the battery 26 side and the inverter 24 side may be included.

[0058] In the electric car 20 of the embodiment, the battery 26 is used as the power storage device. However, a capacitor may be used as the power storage device.

[0059] In the embodiment, the boost converter device is installed in the electric car 20 including the motor 22 for driving. However, the boost converter device may be installed in a hybrid car including an engine in addition to the motor for driving. In addition, the boost converter device may be installed in a vehicle other than an automobile or a mobile body such as a ship or an aircraft. In addition, the boost converter device may be installed in non-moving equipment such as construction equipment.

[0060] The correspondence between the main elements and problems of the embodiment and the main elements of the invention described in the Summary of the Invention section is explained. In the embodiment, the first boost converter 40 and the second boost converter 42 having transistors T11, T12, T21, T22, diodes D11, D12, D21, D22, and reactors L1, L2 correspond to "plural boost converters", the first current detector 41 and the second current detector 43 correspond to "plural current detectors", and the ECU 50 corresponds to "control device".

[0061] In addition, in the correspondence between the main elements and problems of the embodiment and the main elements of the invention recorded in the Summary of the Invention section, the embodiment is an example for specifically describing the method of implementing the invention recorded in the Summary of the Invention section, and therefore does not limit the elements of the invention recorded in the Summary of the Invention section. That is, the interpretation of the invention recorded in the Summary of the Invention section should be based on the description of this section, and the embodiment is only a specific example of the invention recorded in the Summary of the Invention section.

[0062] As mentioned above, although the form for implementing this invention was demonstrated using an embodiment, this invention is not limited to the said embodiment, It is obvious that it can be implemented in various forms within the range which does not deviate from the summary of this invention.

[0063] Industrial Applicability

[0064] The present invention can be utilized in the manufacturing industry of boost converter devices and the like.

Claims

1. A boost converter device, comprising: a plurality of boost converters, each of which is connected in parallel with respect to the power storage device and the load, and each of which has an upper arm, a lower arm, and a reactor, and is capable of boosting the electric power on the power storage device side and supplying the boosted electric power to the load side; A plurality of current detectors, wherein the plurality of current detectors detect the current of each of the reactors; as well as a control device that controls each of the boost converters so as to eliminate a difference between a target current of the corresponding reactor and a detection value of the corresponding current detector, It is characterized in that The control device determines that the current detector is abnormal when the preliminary determination of abnormality continues for a certain time. The determined time is set to: The determination time is shortened as the absolute value of the detection value of the current detector that is not preliminarily determined to be abnormal is larger; or The determination time is shortened as the absolute value of the target current of the reactor corresponding to the current detector that is not preliminarily determined to be abnormal is larger; or The determination time is shorter when the absolute value of the estimated current of the reactor corresponding to the current detector that is preliminarily determined to be abnormal, which is estimated based on the current of any one of the power storage device and the load and the detection value of the current detector that is not preliminarily determined to be abnormal, is larger.

2. The boost converter device according to claim 1, characterized in that Each of the current detectors includes a first current sensor and a second current sensor for detecting a current of the corresponding reactor. The control device preliminarily determines that each of the current detectors is abnormal when a difference between a detection value of the first current sensor and a detection value of the second current sensor is equal to or larger than a threshold value.

3. The boost converter device according to claim 2, characterized in that Each of the current detectors uses the detection value of the first current sensor as the detection value of the current detector.

4. The boost converter device according to any one of claims 1 to 3, characterized in that The control device sets a target supply current to be supplied from the power storage device to the load via the plurality of boost converters so as to eliminate a difference between a target supply voltage and a supply voltage of the load, and sets the target current of each reactor based on the target supply current.

5. The boost converter device according to any one of claims 1 to 4, characterized in that When the control device identifies an abnormality in one of the plurality of current detectors, the control device stops driving all of the plurality of boost converters or stops driving only the boost converter corresponding to the current detector in which the abnormality is identified.

Images