JP5786500B2 - Drive device - Google Patents

Description

  The present invention relates to a drive device, and more specifically, includes a battery connected to a first voltage system, a motor connected to a second voltage system, a reactor and a switching element, and power of the first voltage system. Boosting converter capable of boosting and supplying the voltage to the second voltage system, a capacitor for smoothing the voltage of the second voltage system, a voltage sensor for detecting the voltage of the capacitor, and a current sensor for detecting the current of the reactor And a drive device comprising:

  2. Description of the Related Art Conventionally, a first motor generator that generates electric power or starts an engine using power from an engine, a first inverter for driving the first motor generator, and a first motor that can generate a driving torque of a vehicle. A device comprising: a second motor generator; a second inverter for driving the second motor generator; a battery; and a boost converter capable of boosting power from the battery and supplying the boosted power to the first and second inverters When the rotational speed of the second motor generator exceeds the limit value and the torque command value of the second motor generator is 0, the voltage command of the input voltage of the first and second inverters is reduced by a predetermined amount. A drive device has been proposed (see, for example, Patent Document 1). In this apparatus, such processing prevents overvoltage of the input voltages of the first and second inverters that may occur in association with torque reduction control of the second motor generator.

International Publication No. 2006/095497

  In recent years, it has been considered that a current flowing through a reactor of a boost converter is detected by a current sensor and used for controlling the boost converter. This is because the input voltage of the first and second inverters increases due to the surge voltage acting on the first and second inverters when the current flowing through the reactor changes from a positive value to a negative value across the value 0. This is to suppress the increase and protect the switching element of the boost converter and increase the command value of the input voltage of the first and second inverters. In this case, it is sufficient if the current sensor is normal. However, if an abnormality occurs in the current sensor, the current of the reactor cannot be used for controlling the boost converter.

  The drive device of the present invention is mainly intended to cope more appropriately when an abnormality has occurred in a current sensor that detects a reactor current of a boost converter.

  The drive device of the present invention employs the following means in order to achieve the main object described above.

The drive device of the present invention is
A second battery connected to the first voltage system; a motor connected to the second voltage system; a reactor and a switching element; A step-up converter that can supply the voltage of the second voltage system, a voltage sensor that detects the voltage of the capacitor, a current sensor that detects the current of the reactor, and a target of the capacitor Setting the voltage command of the capacitor by limiting the voltage with a first allowable upper limit voltage, and setting the target current of the reactor by feedback control using the set voltage command and the detected voltage of the capacitor; A target duty ratio is set by feedback control using the set target current and the detected reactor current, and the set target duty is set. In the driving device and a control means for controlling the boost converter with,
The control means sets a voltage command for the capacitor by limiting the target voltage of the capacitor with a second allowable upper limit voltage lower than the first allowable upper limit voltage when an abnormality occurs in the current sensor, A means for setting a target duty ratio by feedback control using the set voltage command and the detected voltage of the capacitor, and controlling the boost converter using the set target duty ratio.
A drive device characterized by that.

  In the driving device of the present invention, the capacitor voltage command is set by limiting the target voltage of the capacitor with the first allowable upper limit voltage, and feedback using the set voltage command and the voltage of the capacitor detected by the voltage sensor is performed. The target current of the reactor is set by control, the target duty ratio is set by feedback control using the set target current and the reactor current detected by the current sensor, and the boost converter is controlled using the set target duty ratio In this case, when an abnormality occurs in the current sensor, the capacitor voltage command is set by limiting the target voltage of the capacitor with the second allowable upper limit voltage lower than the first allowable upper limit voltage. Feedback control using the voltage of the capacitor detected by the voltage sensor. It sets a target duty ratio Te, and controls the boost converter using the target duty ratio set. When controlling the boost converter using the current of the reactor detected by the current sensor, it is possible to improve the controllability of the boost converter compared to controlling the boost converter without using the reactor current. The voltage command of the capacitor can be made higher. On the other hand, when controlling the step-up converter without using the reactor current due to an abnormality in the current sensor, if the same voltage as when there is no abnormality in the current sensor is used as the capacitor voltage command, Capacitor voltage may be overvoltage. In the driving device of the present invention, when an abnormality occurs in the current sensor, the voltage command of the capacitor is set using the second allowable upper limit voltage lower than the first allowable upper limit voltage when no abnormality occurs. When the boost converter is controlled without using the reactor current, it is possible to suppress the capacitor voltage from becoming an overvoltage, and it is possible to further protect each element and capacitor of the boost converter. In other words, it can be said that it is possible to cope more appropriately when an abnormality occurs in the current sensor. Here, the “first allowable upper limit voltage” is set so that the voltage of the capacitor does not exceed the breakdown voltage of each element of the boost converter and the capacitor when the boost converter is controlled using the current of the reactor. It can also be. The “second allowable upper limit voltage” is lower than the first allowable upper limit voltage, and when the boost converter is controlled without using the reactor current, the voltage of the capacitor is the breakdown voltage of each element of the boost converter and the capacitor. It can also be set within a range not exceeding.

  In such a driving apparatus of the present invention, the control means is configured such that when the required torque required for the motor is reduced, when the abnormality occurs in the current sensor, compared with when the abnormality does not occur in the current sensor. It is also possible to control the motor so that torque that gently follows the required torque is output from the motor.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 carrying the drive device as one Example of this invention. It is a block diagram which shows the outline of a structure of an electric drive system. 4 is a flowchart showing an example of a boost control routine executed by an electronic control unit 50. It is explanatory drawing which shows an example of the time change state of the duty signal based on target duty ratio Duty *, the on-off state of transistors T31 and T32, and the on-off state of an upper arm and a lower arm. It is explanatory drawing which shows an example of the mode of a time change with the abnormality determination flag F, the voltage VH of the drive voltage system electric power line 42, and voltage command VH *. It is explanatory drawing which shows an example of the mode change of the request torque Tr * when the abnormality has arisen in the current sensor 41, the torque command Tm * of the motor 32, and the voltage VH of the drive voltage system power line. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of an electric vehicle 20 equipped with a drive device as an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of an electric drive system. As shown in FIG. 1, the electric vehicle 20 according to the embodiment drives a motor 32 that can input and output power to a drive shaft 22 connected to drive wheels 26 a and 26 b via a differential gear 24, and a motor 32. Inverter 34, a battery 36 configured as, for example, a lithium ion secondary battery, a power line (hereinafter referred to as a drive voltage system power line) 42 to which the inverter 34 is connected, and a power line (hereinafter referred to as a drive voltage system power line) 42. A boost converter that adjusts the voltage VH of the drive voltage system power line 42 and exchanges power between the drive voltage system power line 42 and the battery voltage system power line 44. 40 and an electronic control unit 50 for controlling the entire vehicle.

  The motor 32 is configured as a well-known synchronous generator motor including a rotor embedded with permanent magnets and a stator wound with a three-phase coil. As shown in FIG. 2, the inverter 34 includes transistors T11 to T16 as six switching elements, and six diodes D11 to D16 connected in parallel to the transistors T11 to T16 in the reverse direction. The transistors T11 to T16 are arranged in pairs so as to be on the source side and the sink side with respect to the positive and negative buses of the drive voltage system power line 42, and each of the connection points between the paired transistors. The three-phase coils (U-phase, V-phase, W-phase) of the motor 32 are connected to each other. Therefore, a rotating magnetic field can be formed in the three-phase coil and the motor 32 can be driven to rotate by adjusting the ratio of the on-time of the transistors T11 to T16 while the voltage is applied to the inverter 34. A smoothing capacitor 46 is connected to the positive and negative buses of the drive voltage system power line 42.

  As shown in FIG. 2, the boost converter 40 is configured as a boost converter including two transistors T31 and T32, two diodes D31 and D32 connected in parallel in opposite directions to the transistors T31 and T32, and a reactor L. . The two transistors T31 and T32 are respectively connected to the positive bus of the drive voltage system power line 42, the negative bus of the drive voltage system power line 42 and the battery voltage system power line 44, and the connection point between the transistors T31 and T32. A reactor L is connected to the positive electrode bus of the battery voltage system power line 44. Therefore, by turning on and off the transistors T31 and T32, the power of the battery voltage system power line 44 is boosted and supplied to the drive voltage system power line 42, or the power of the drive voltage system power line 42 is lowered to reduce the battery voltage system. Or can be supplied to the power line 44. A smoothing capacitor 48 is connected to the positive and negative buses of the battery voltage system power line 44. Hereinafter, the transistor T31 and the diode D31 may be collectively referred to as an upper arm, and the transistor T32 and the diode D32 may be collectively referred to as a lower arm.

  The electronic control unit 50 is configured as a microprocessor centered on the CPU 52, and includes a ROM 54 that stores a processing program, a RAM 56 that temporarily stores data, and an input / output port (not shown) in addition to the CPU 52. . The electronic control unit 50 includes a rotational position θm of the rotor of the motor 32 from a rotational position detection sensor 32a that detects the rotational position of the rotor of the motor 32, and phase currents flowing in the V phase and W phase of the three-phase coil of the motor 32. The phase currents Iu and Iv from the current sensors 33U and 33V, the inter-terminal voltage Vb from the voltage sensor 37a attached between the terminals of the battery 36, and the charge from the current sensor 37b attached to the output terminal of the battery 36. Discharge current Ib, battery temperature Tb from temperature sensor 37c attached to battery 36, reactor current IL from current sensor 41 attached between the connection point between transistors T31 and T32 of boost converter 30 and reactor L ( When flowing from the battery voltage system power line 44 side to the connection point side of the transistors T31 and T32 Positive), the voltage of the capacitor 46 from the voltage sensor 46a attached between the terminals of the capacitor 46 (voltage of the drive voltage system power line 42) VH, the capacitor from the voltage sensor 48a attached between the terminals of the capacitor 48 48 voltage (voltage of the battery voltage system power line 44) VL, an ignition signal from the ignition switch 60, a shift position SP from the shift position sensor 62 that detects the operation position of the shift lever 61, and a depression amount of the accelerator pedal 63 are detected. The accelerator opening position Acc from the accelerator pedal position sensor 64, the brake pedal position BP from the brake pedal position sensor 66 for detecting the depression amount of the brake pedal 65, the vehicle speed V from the vehicle speed sensor 68, etc. are input via the input port. Have The In the embodiment, the current sensor 37b and the current sensor 41 are designed so that the current sensor 37b has higher detection accuracy and the current sensor 41 has higher responsiveness. From the electronic control unit 50, switching control signals to the transistors T11 to T16 of the inverter 34, switching control signals to the transistors T31 and T32 of the boost converter 40, and the like are output via an output port. The electronic control unit 50 calculates the electrical angle θe and the rotational speed Nm of the rotor of the motor 32 based on the rotational position θm of the rotor of the motor 32 detected by the rotational position detection sensor 32a, or detects it by the current sensor 37b. On the basis of the charged / discharge current Ib of the battery 36, the storage ratio SOC, which is the ratio of the amount of power that can be discharged from the battery 36 at that time, to the total capacity is calculated, or based on the calculated storage ratio SOC and the battery temperature Tb The input / output limits Win and Wout, which are the maximum allowable power that may charge and discharge the battery 36, are calculated.

  In the electric vehicle 20 of the embodiment configured as described above, the electronic control unit 50 sets the required torque Tr * to be output to the drive shaft 22 in accordance with the accelerator opening Acc and the vehicle speed V, and the set required torque Tr *. Are subjected to a gradual change process such as a rate process and an annealing process to set a temporary torque Tmtmp as a temporary value of torque to be output from the motor 32, and input / output limits Win and Wout of the battery 36 are set to the motor 32. Torque limits Tmin and Tmax are set as upper and lower limits of the torque that may be output from the motor 32 by dividing by the rotational speed Nm, and the torque that should be output from the motor 32 by limiting the temporary torque Tmtmp by the torque limits Tmin and Tmax Is set as a torque command Tm *. For the inverter 34, the transistors T11 to T16 are subjected to switching control so that the motor 32 is driven by the set torque command Tm *. Further, the boost converter 40 is controlled by executing a boost control routine illustrated in FIG. 3 using the torque command Tm * and the rotation speed Nm. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the step-up control routine is executed, the electronic control unit 50 first starts the torque command Tm * of the motor 32, the rotation speed Nm, the voltage VH of the drive voltage system power line 42 from the voltage sensor 46a, and the battery from the voltage sensor 48a. Processing for inputting data necessary for control, such as voltage VL of voltage system power line 44, current IL of reactor L from current sensor 41, abnormality determination flag F indicating whether or not abnormality has occurred in current sensor 41, is executed. (Step S100). Here, the abnormality determination flag F is a flag in which a value 0 is set as an initial value and a value 1 is set when it is determined that an abnormality has occurred in the current sensor 41. The determination that abnormality has occurred in the current sensor 41 is made by determining the current IL and current of the reactor L detected by the current sensor 41 in a state where the boost converter 40 is stopped and the motor 32 is driven by the inverter 34. This can be performed when the difference from the charge / discharge current Ib detected by the sensor 37b is larger than the allowable range or when the current IL of the reactor L is not input from the current sensor 41 for a predetermined time.

  When the data is thus input, the target voltage VHtag of the drive voltage system power line 42 is set based on the input torque command Tm * of the motor 32 and the rotation speed Nm (step S110). Here, in the embodiment, the target voltage VHtag is set to a voltage at which the motor 32 can be driven at a target drive point consisting of the torque command Tm * of the motor 32 and the rotation speed Nm.

  Subsequently, the value of the input abnormality determination flag F is checked (step S120). When the abnormality determination flag F is 0, it is determined that no abnormality has occurred in the current sensor 41, and the target voltage of the drive voltage system power line 42 is determined. The voltage command VH * of the drive voltage system power line 42 is set by limiting VHtag with the allowable upper limit voltage VHlim1 (step S130), and the voltage command VH * of the set drive voltage system power line 42 and the drive voltage system power line 42 are set. Using the voltage VH, the voltage VL of the battery voltage system power line 44, the capacitance C of the capacitor 46, and the execution interval Δt of this routine (the acquisition cycle of the voltage VH, the setting cycle of the voltage command VH *), ) To set the reactor L current command IL * (step S140), the reactor L current command IL *, the reactor L current IL and the battery power Using the voltage VL of system power line 44 and voltage command VH * of drive voltage system power line 42, the target duty ratio Duty * of boost converter 40 is set by equation (2) (step S150), and the set target duty ratio The boost converter 40 is controlled using Duty * (step S180), and this routine is terminated. Here, Expression (1) is a relational expression in the feedback control using the voltage command VH * and the voltage VH of the drive voltage system power line 42, the first term on the right side is a proportional term in the feedback term, The second term is an integral term in the feedback term. Equation (2) is a relational expression in feedback control using the current command IL * of the reactor L and the current IL of the reactor L, the first term on the right side is the feedforward term, and the second term on the right side is the feedback. It is a proportional term in the term, and the third term on the right side is an integral term in the feedback term. In equations (1) and (2), “Kp1” and “Kp2” are proportional term gains, and “Ki1” and “Ki2” are integral term gains. Further, in the expression (1), the portion excluding “Kp1” and “Ki1” in the first term and the second term on the right side is the energy per unit time (“C” required for adjusting the voltage VH of the drive voltage system power line 42. / 2 ”and the square of“ VH * ”and the product of“ C / 2 ”and the square of“ VH ”divided by“ Δt ”) divided by“ VL ”. It corresponds to the value converted into current value. Hereinafter, the reactor L current command IL * is set by feedback control using the voltage command VH * and voltage VH of the drive voltage system power line 42, and feedback control using the reactor L current command IL * and current IL is performed. A series of processes for setting the target duty ratio Duty * of the boost converter 40 is referred to as a voltage / current FB process. The above-described allowable upper limit voltage VHlim1 is such that when the boost converter 40 is controlled using the current IL of the reactor L (using the voltage current FB process), the voltage VH of the drive voltage system power line 42 is A relatively high value is set in a range not exceeding the breakdown voltage of the capacitor 46. The allowable upper limit voltage VHlim1 is, for example, the maximum voltage fluctuation of the drive voltage system power line 42 assumed when the boost converter 40 is controlled using the current IL of the reactor L (the lower arm of the boost converter 40 or the drive voltage system power). (Including the surge voltage acting on the line 42) can be obtained by experiment or analysis, and can be set based on the obtained maximum voltage fluctuation and the specifications of each element of the boost converter 40 and the capacitor 46. In the embodiment, the boost converter 40 is controlled by turning on a duty signal based on the target duty ratio Duty * (the time corresponding to the target duty ratio Duty * of the switching periods of the transistors T31 and T32 is turned on) By switching the transistors T31 and T32 in consideration of dead time (time for turning off the transistors T31 and T32 so that the drive voltage system power line 42 is not short-circuited) using a signal that turns off with respect to time. To do.

  FIG. 4 is an explanatory diagram illustrating an example of a time change of a duty signal based on the target duty ratio Duty *, ON / OFF states of the transistors T31 and T32, and ON / OFF states of the upper arm and the lower arm. FIG. 4 shows the case where the target duty ratio Duty * is 0.5. In FIG. 4, when the transistors T31 and T32 are switched on and off, a time corresponding to the target duty ratio Duty * value of 0.1 is provided as a dead time. As can be seen from FIG. 4, the actual duty ratio Duty of the upper arm (the ratio of the time during which current flows through the upper arm with respect to the switching period of the transistors T31 and T32) is when the current IL of the reactor L is positive (battery voltage system power). When the current flows from the line 44 side to the connection point side of the transistors T31 and T32), it becomes larger than the target duty ratio Duty * (the value is 0.6 in FIG. 4), and the current IL of the reactor L is negative. Is smaller than the target duty ratio Duty * (the value is 0.4 in FIG. 4). This is because when the current IL of the reactor L is positive, a current flows through the diode D31 during the dead time, but when the current IL of the reactor L is negative, no current flows through the diode D31 during the dead time.

  Returning to the description of the boost control routine of FIG. When the abnormality determination flag F is 1 in step S110, it is determined that an abnormality has occurred in the current sensor 41, and the target voltage VHtag of the drive voltage system power line 42 is limited by the allowable upper limit voltage VHlim2 lower than the allowable upper limit voltage VHlim1. The voltage command VH * of the drive voltage system power line 42 is set (step S160), the voltage VH of the drive voltage system power line 42, the voltage command VH * of the drive voltage system power line 42, and the voltage of the battery voltage system power line 44 are set. The target duty ratio Duty * used for switching of the transistors T31 and T32 of the boost converter 40 is set by the following equation (3) using VL (step S170), and the boost converter 40 is set using the set target duty ratio Duty *. The transistors T31 and T32 are subjected to switching control (step S180). , To end the present routine. Here, Expression (3) is a relational expression in feedback control using the voltage command VH * and the voltage VH of the drive voltage system power line 42, the first term on the right side is the feedforward term, and the second term on the right side The term is a proportional term in the feedback term, and the third term on the right side is an integral term in the feedback term. In equation (3), “Kp3” is the gain of the proportional term, and “Ki3” is the gain of the integral term. Hereinafter, the process of setting the target duty ratio Duty * of the boost converter 40 by feedback control using the voltage command VH * and the voltage VH of the drive voltage system power line 42 is referred to as voltage FB process. The allowable upper limit voltage VHlim2 is lower than the above-described allowable upper limit voltage VHlim1, and when the boost converter 40 is controlled without using the current IL of the reactor L (using the voltage FB process), the voltage VH of the drive voltage system power line 42 is A relatively high value is set within a range not exceeding the breakdown voltage of each element of the boost converter 40 and the capacitor 46. The allowable upper limit voltage VHlim2 is, for example, the maximum voltage fluctuation of the drive voltage system power line 42 assumed when the boost converter 40 is controlled without using the current IL of the reactor L (the lower arm or the drive voltage system of the boost converter 40). (Including a surge voltage acting on the power line 42) can be obtained by experiment or analysis, and can be set based on the obtained maximum voltage fluctuation and the specifications of each element of the boost converter 40 and the capacitor 46. When an abnormality occurs in the current sensor 41, the target duty ratio Duty * is set using the voltage VH of the drive voltage system power line 42 and the voltage command VH * as described above, and the transistors T31 and T32 of the boost converter 40 are set. By performing switching control, the voltage VH of the drive voltage system power line 42 can be adjusted. Hereinafter, when an abnormality occurs in the current sensor 41 (when the boost converter 40 is controlled using the voltage FB process), no abnormality occurs in the current sensor 41 (when the voltage converter FB process is used). The reason why the voltage command VH * is set using the allowable upper limit voltage VHlim2 lower than the allowable upper limit voltage VHlim1 when the control is performed) will be described.

  As described above, the actual duty ratio Duty of the upper arm (ratio of time during which current flows through the upper arm with respect to the switching period of the transistors T31 and T32) is when the current IL of the reactor L is positive (battery voltage power line 44). (When current flows from the side to the connection point between the transistors T31 and T32), the current becomes larger than the target duty ratio Duty *, and smaller than the target duty ratio Duty * when the current IL of the reactor L is negative. Become. In boost converter 40, voltage VH of drive voltage system power line 42 tends to increase as actual duty ratio Duty of the upper arm decreases, so that current IL of reactor L decreases from a positive value to a value 0. As the actual duty ratio Duty of the upper arm decreases, the surge voltage acting on the lower arm of the boost converter 40 and the drive voltage system power line 42 increases, and the voltage VH of the drive voltage system power line 42 increases. Is expected to rise. When no abnormality occurs in the current sensor 41 (when controlling the boost converter 40 using the voltage / current FB process), if the current IL of the reactor L becomes a negative value, as can be seen from the equation (2), Since the target duty ratio Duty * is increased, thereby suppressing the decrease in the actual duty ratio Duty of the upper arm, it is considered that the increase in the voltage VH of the drive voltage system power line 42 due to the surge voltage increase is not so large. It is done. For this reason, a relatively high value can be used as the allowable upper limit voltage VHlim1. On the other hand, when abnormality has occurred in current sensor 41 (when boost converter 40 is controlled using voltage FB processing), it is impossible to grasp that current IL of reactor L has become negative. Due to the decrease in the actual duty ratio Duty of the arm, the degree of increase of the voltage VH of the drive voltage system power line 42 due to the increase of the surge voltage becomes relatively large (in the case of controlling the boost converter 40 using the voltage current FB process). It is considered to be larger than that). In the embodiment, based on this fact, when the abnormality occurs in the current sensor 41, the allowable upper limit voltage VHlim2 lower than the allowable upper limit voltage VHlim1 when the abnormality does not occur in the current sensor 41 is used. Boost converter 40 is controlled using voltage command VH * obtained by limiting target voltage VHtag. As a result, the voltage VH of the drive voltage system power line 42 can be suppressed from becoming an overvoltage, and each element of the boost converter 40 and the capacitor 46 can be further protected. FIG. 5 shows an example of how the abnormality determination flag F, the voltage VH of the drive voltage system power line 42, and the voltage command VH * change with time.

  According to the electric vehicle 20 of the embodiment described above, when the abnormality occurs in the current sensor 41, the driving voltage system power is at the allowable upper limit voltage VHlim2 lower than the allowable upper limit voltage VHlim1 when no abnormality occurs in the current sensor 41. The voltage command VH * of the drive voltage system power line 42 is set by limiting the target voltage VHtag of the line 42, the voltage of the capacitor 46 (voltage of the drive voltage system power line 42) VH and the drive voltage system power from the voltage sensor 46a. Since the target duty ratio Duty * is set by feedback control using the voltage command VH * of the line 42 and the boost converter 40 is controlled using the set target duty ratio Duty *, the current of the reactor L from the current sensor 41 When controlling the boost converter 40 without using the IL, the drive voltage system power line Can second voltage VH can be inhibited from an overvoltage can each element or capacitor 46 of the boost converter 40 more protection.

  In the electric vehicle 20 according to the embodiment, the temporary torque Tmtmp of the motor 32 is set by subjecting the required torque Tr * to a gradual change process such as a rate process and an annealing process, and the set temporary torque Tmtmp is set to the torque limits Tmin, Tmax. The torque command Tm * of the motor 32 is set in a limited manner, and the transistors T11 to T16 of the inverter 34 are subjected to switching control so that the motor 32 is driven by the set torque command Tm *. The degree of change may be changed depending on whether or not an abnormality has occurred in current sensor 41 (which one of voltage current FB processing and voltage FB processing is used to control boost converter 40). In this case, for example, when the current sensor 41 is abnormal when the required torque Tr * is decreased (when the boost converter 40 is controlled using the voltage FB process), the current sensor 41 is abnormal. The temporary torque Tmtmp may be set so as to change more slowly than when there is no voltage (when the voltage / current FB process is used to control the boost converter 40). FIG. 6 is an explanatory diagram showing an example of how the required torque Tr *, the torque command Tm * of the motor 32, and the voltage VH of the drive voltage system power line 42 change over time when the current sensor 41 is abnormal. . In the figure, the alternate long and short dash line shows a state of a comparative example in which the torque command Tm * is changed by the same slow change process as when no abnormality has occurred in the current sensor 41, and the solid line indicates that there is no abnormality in the current sensor 41. The mode of the Example which changes torque instruction Tm * gently is shown. When the torque command Tm * is decreased, a part of the power supplied from the battery voltage system power line 44 side to the drive voltage system power line 42 side by the boost converter 40 is easily charged to the capacitor 46 due to the decrease in power consumption of the motor 32. The voltage VH of the drive voltage system power line 42 is likely to increase. In particular, it is considered that the voltage VH of the drive voltage system power line 42 is likely to increase as the rate of decrease in the torque command Tm * increases (as the rate decreases sharply). Further, as described above, when current IL of reactor L changes from a positive value to a negative value across value 0, the surge voltage acting on lower arm of boost converter 40 and drive voltage system power line 42 increases. The voltage VH of the drive voltage system power line 42 is likely to increase. In this modification, based on these facts, when an abnormality has occurred in the current sensor 41, no abnormality has occurred in the current sensor 41, as indicated by the solid line in the figure (refer to the one-dot chain line of the torque command Tm *). The torque command Tm * is changed more slowly than that. Thereby, an increase in the voltage VH of the drive voltage system power line 42 can be suppressed. As a result, the voltage VH of the drive voltage system power line 42 can be further suppressed from becoming an overvoltage, and each element of the boost converter 40 and the capacitor 46 can be further protected.

  In the electric vehicle 20 of the embodiment, when there is no abnormality in the current sensor 41, the reactor L current is obtained by feedback control according to the above equation (2) using the voltage command VH * and the voltage VH of the drive voltage system power line 42. The command IL * is set, but the current command IL * of the reactor L is set by feedback control according to the following equation (4) using the voltage command VH * and the voltage VH of the drive voltage system power line 42. Also good. In Expression (4), “Kp4” is the gain of the proportional term, and “Ki4” is the gain of the integral term.

  In the embodiment, the present invention is applied to the electric vehicle 20 including the motor 32 capable of inputting and outputting power to the drive shaft 22 connected to the drive wheels 26a and 26b. As described above, the present invention may be applied to a hybrid vehicle 120 including the engine 122 and the motor 124 connected to the drive shaft 22 through the planetary gear mechanism 126 and the motor 32 capable of inputting / outputting power to / from the drive shaft 22. Alternatively, as illustrated in the hybrid vehicle 220 of the modification of FIG. 8, the engine 122, the inner rotor 232 connected to the crankshaft of the engine 122, and the drive shaft 22 connected to the drive wheels 26a and 26b are connected. The outer rotor 234 and a part of the power from the engine 122 to the drive shaft 22 and the remainder The present invention may be applied to a hybrid vehicle 220 including a counter-rotor motor 230 that converts motive power into electric power and a motor 32 that can input and output power to the drive shaft 22, or may be applied to the hybrid vehicle 320 of the modified example of FIG. 9. As illustrated, the motor 32 is attached to the drive shaft 22 via the transmission 330 and the engine 122 is connected to the rotation shaft of the motor 32 via the clutch 229, and the power from the engine 122 is used as the rotation shaft of the motor 32. And the hybrid vehicle 320 that outputs the power from the motor 32 to the drive shaft 22 via the transmission 330 and outputs the power to the drive shaft 22 via the transmission 330.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the battery 36 corresponds to “battery”, the motor 32 corresponds to “motor”, the boost converter 40 corresponds to “boost converter”, the capacitor 46 corresponds to “capacitor”, and the voltage sensor 46 a It corresponds to a “voltage sensor”, the current sensor 41 corresponds to a “current sensor”, and the electronic control unit 50 corresponds to a “control unit”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of drive devices.

  20 electric vehicle, 22 drive shaft, 24 differential gear, 26a, 26b drive wheel, 32 motor, 32a rotational position detection sensor, 33U, 33v current sensor, 34 inverter, 36 battery, 37a voltage sensor, 37b current sensor, 37c temperature sensor , 40 Boost converter, 41 Current sensor, 42 Drive voltage system power line, 44 Battery voltage system power line, 46, 48 Capacitor, 46a, 48a Voltage sensor, 50 Electronic control unit, 52 CPU, 54 ROM, 56 RAM, 60 Ignition Switch 61 shift lever 62 shift position sensor 63 accelerator pedal 64 accelerator pedal position sensor 65 brake pedal 66 brake pedal position sensor 68 vehicle speed sensor 120 220, 320 a hybrid vehicle, 122 engine, 124 motor, 126 a planetary gear mechanism, 329 a clutch, 330 transmission, D11-D16, D31, D32 diodes, L reactor, T11 to T16, T31, T32 transistor.

Claims (1)

A second battery connected to the first voltage system; a motor connected to the second voltage system; a reactor and a switching element; A step-up converter that can supply the voltage of the second voltage system, a voltage sensor that detects the voltage of the capacitor, a current sensor that detects the current of the reactor, and a target of the capacitor Setting the voltage command of the capacitor by limiting the voltage with a first allowable upper limit voltage, and setting the target current of the reactor by feedback control using the set voltage command and the detected voltage of the capacitor; A target duty ratio is set by feedback control using the set target current and the detected reactor current, and the set target duty is set. In the driving device and a control means for controlling the boost converter with,
The control means sets a voltage command for the capacitor by limiting the target voltage of the capacitor with a second allowable upper limit voltage lower than the first allowable upper limit voltage when an abnormality occurs in the current sensor, Means for setting a target duty ratio by feedback control using the set voltage command and the detected voltage of the capacitor, and controlling the boost converter using the set target duty ratio;
Further, when the required torque required for the motor is reduced, the control means is more gradual to the required torque when an abnormality occurs in the current sensor than when no abnormality occurs in the current sensor. Is a means for controlling the motor so that torque following the motor is output from the motor.
A drive device characterized by that.

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