JP2013005582A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid unexpected regenerative breaking of an electric motor and surely suppress the overcharging of a secondary battery, even if angle shift occurs in a sensor for detecting the rotation angle of the rotary shaft of the electric motor.SOLUTION: When controlling the motor by setting current instructions Id*, Iq* so that a current Id in the minus direction is flown in a d-axis and the current is not flown in a q-axis, the rotation angle θ is corrected in a direction from regeneration to powering by correcting the rotation angle θ from a rotation angle sensor used for controlling to a reverse rotation direction during the normal rotation of the motor and correcting it to a normal rotation direction during the reverse rotation of the motor. As a result, even if offset error is included in the rotation angle sensor, a current in the reverse direction of the rotation direction of the motor MG2 is not flown in q-axis, namely a regenerative torque can be made not to be output by controlling the motor MG2 based on the corrected rotation angle θ. As a result, unexpected regeneration of the motor can be prevented and the overcharging of the secondary battery can be suppressed.

Description

  The present invention includes an electric motor capable of inputting / outputting driving power, a secondary battery capable of exchanging electric power with the electric motor, and a state detection sensor for detecting the state of the electric motor, and a required torque required for the electric motor And an electric vehicle that controls the electric motor based on the state of the electric motor.

  Conventionally, this type of electric vehicle detects a three-phase motor capable of generating power, an inverter that drives the motor, a DC power source (battery) that exchanges power with the motor, and a rotational position (rotation angle) of the motor. A d-axis current command in a dq coordinate system having a d-axis and a q-axis as coordinate axes based on the torque command of the motor, and a rotational position sensor that detects current flowing in each phase of the motor. q-axis current command is set, and each phase current of the motor from the current sensor is converted into d-axis current and q-axis current using the rotation angle of the motor from the rotational position sensor (three-phase two-phase conversion), d The d-axis voltage command is set by feedback control based on the deviation between the axis current command and the d-axis current, and the q-axis voltage command is set by feedback control based on the deviation between the q-axis current command and the q-axis current. The d-axis voltage command and the q-axis voltage command are converted into each phase voltage command to be applied to each phase of the motor (two-phase three-phase conversion) using the rotation angle of the motor from There has been proposed one that drives a motor by generating a PWM signal based on the switching control of an inverter (see, for example, Patent Document 1). In this vehicle, the relationship between the torque and the current advance angle when the torque ripple of the motor is minimized is obtained in advance and stored as a map, and when the motor torque command value is given, the relationship is based on the torque command value. The current advance angle α is extracted from the map. Then, the sensor value θ from the rotational position sensor is corrected by the extracted current advance angle α, and this correction value (θ + α) is used for the above-described three-phase two-phase conversion and two-phase three-phase conversion.

Japanese Patent Laying-Open No. 2005-237054

  In the above-described vehicle, if an error is included in the rotational position sensor, the torque actually output from the motor is different from the torque command, and in some cases, the battery is overcharged. Considering the case where the motor is controlled in a state where the battery storage ratio (SOC) is high and the battery cannot be charged, the inverter is controlled so that the current flows only to the d axis in the dq coordinate system described above. For example, since regenerative torque is not output from the motor, the battery should not be charged. However, if an error is included in the rotational position sensor, the d axis based on the detected value is deviated from the actual d axis, so that current also flows through the q axis and the motor may be regenerated. . If the motor regenerates in a state where the battery cannot be charged, there is a possibility that the regenerative electric power will continue to be charged in the battery and the battery may be overcharged. Such a problem is not limited to the case where the rotational position sensor includes an error, but also when another state detection sensor used for controlling the motor, such as a current sensor that detects a phase current of the motor, includes an error. Can occur.

  Even if the electric vehicle of the present invention includes a detection error in the sensor that detects the state of the electric motor, the main purpose is to more reliably prevent overcharge of the secondary battery by avoiding unexpected regenerative braking of the electric motor. Objective.

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

The electric vehicle of the present invention is
An electric motor capable of inputting / outputting driving power; a secondary battery capable of exchanging electric power with the electric motor; a state detection sensor for detecting a state of the electric motor; a required torque required for the electric motor; And an electric vehicle comprising control means for controlling the electric motor based on the state,
The gist is provided with a detection value correction means for correcting the detection value detected by the state detection sensor in a direction from regeneration to power running when the storage ratio of the secondary battery is equal to or higher than a predetermined ratio. .

  In the electric vehicle according to the present invention, when the electric motor is controlled based on the required torque required for the electric motor and the state of the electric motor, the state of the electric motor is detected when the storage ratio of the secondary battery is equal to or higher than a predetermined ratio. The detection value from the detection sensor is corrected in a direction in which the control of the electric motor is directed from regeneration to power running. Thereby, even if a detection error is included in the state detection sensor, unexpected regenerative braking of the electric motor can be avoided. As a result, overcharge of the secondary battery can be suppressed more reliably.

  In such an electric vehicle according to the present invention, the state detection sensor is a rotation angle detection sensor that detects a rotation angle of the electric motor, and the control means is based on the rotation angle of the electric motor based on the required torque. A means for setting a d-axis current command and a q-axis current command in the -q coordinate system, and controlling the electric motor based on the set current commands, wherein the detected value correcting means is the detected The rotation angle of the electric motor may be a means for correcting the electric motor in a direction from regeneration to power running. In this way, unexpected regenerative braking of the electric motor can be avoided even if an angle deviation occurs in the rotation angle detection sensor.

  In the electric vehicle according to the present invention, the electric motor is a three-phase AC electric motor, the state detection sensor is a phase current detection sensor that detects a phase current of the electric motor, and the control means is configured to adjust the required torque. Based on the d-axis current command and the q-axis current command in the dq coordinate system, the d-axis current command and the d-axis current obtained by the phase current and the feedback control based on the deviation are used to set the d-axis current command. And the q-axis voltage command is set by feedback control based on a deviation between the q-axis current command and the q-axis current obtained by the phase current, and the voltage command is set based on each set voltage command. The detection value correction means may be a means for correcting the detected phase current so that the control of the motor moves from regeneration to power running. That. In this way, unexpected regenerative braking of the electric motor can be avoided even if an error is included in the phase current detection sensor.

  Further, in the electric vehicle according to the present invention, the detection value correcting means may detect the detection value detected by the state detection sensor when the secondary battery is charged in a direction in which the control of the electric motor moves from regeneration to power running. It can also be a means for correcting.

  In the electric vehicle according to the present invention, the detection value correction means corrects the detection value detected by the state detection sensor when the vehicle speed is equal to or higher than a predetermined vehicle speed in a direction in which the control of the electric motor is directed from regeneration to power running. It can also be assumed.

  In the electric vehicle of the present invention, the control means is means for controlling the electric motor by switching a plurality of control modes including rectangular wave control and sine wave control, and the detection value correcting means is the rectangular wave control. It may be a means for correcting the detection value detected by the state detection sensor when the electric motor is controlled by the control in a direction from the regeneration toward the power running.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is explanatory drawing which shows an example of the relationship between battery temperature Tb and the basic value of input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the relationship between electrical storage ratio SOC and a correction coefficient. It is a block diagram which shows an example of the control block which controls motor MG2. It is explanatory drawing which shows an example of the map for control mode setting for setting the control mode of motor MG2. 4 is a flowchart showing an example of a rotation angle correction routine executed by a motor ECU 40. It is explanatory drawing which shows a mode that the rotation angle (theta) from the rotation angle sensor 44 used for control is corrected when controlling the motor MG2 so that the negative electric current Id may be sent through d axis and torque may not be output from motor MG2. 4 is a flowchart showing an example of a phase current correction routine executed by a motor ECU 40. It is explanatory drawing which shows the current vector at the time of coordinate-transforming in the state in which the gain error is contained in the phase currents Iv and Iw from the current sensors 46V and 46W. When any two currents of U phase, V phase, and W phase of motor MG2 are detected by the sensor, the combination of the motor rotation direction regenerated by motor MG2 and the sign of the gain error included in the current detection value of each phase It is explanatory drawing explaining these. 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. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 420 according to a modification.

  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 a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 configured as an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and a crankshaft 26 serving as an output shaft of the engine 22. A carrier 34 is connected to a plurality of pinion gears 33 via a damper 28, and a ring gear 32 is connected to a ring gear shaft 32a as a drive shaft connected to drive wheels 39a, 39b via a gear mechanism 37 and a differential gear 38. A triaxial power distribution and integration mechanism 30 connected and configured as a planetary gear mechanism, a motor MG1 configured as a well-known synchronous generator motor and having a rotor connected to the sun gear 31 of the power distribution and integration mechanism 30; A ring gear shaft as a drive shaft constructed as a known synchronous generator motor A motor MG2 having a rotor connected to 2a via a reduction gear 35, inverters 41 and 42 configured as drive circuits for driving the motors MG1 and MG2, and an inverter 41 configured as a lithium ion secondary battery, for example. The battery 50 which exchanges electric power with motor MG1, MG2 via 42, and the electronic control unit 70 for hybrids which controls the whole vehicle are provided.

  The engine 22 is controlled by an engine electronic control unit (hereinafter referred to as engine ECU) 24 such as fuel injection control, ignition control, and intake air amount adjustment control. Signals from various sensors that detect the operating state of the engine 22 are input to the engine ECU 24, and the engine ECU 24 controls driving to a throttle valve, a fuel injection valve, a spark plug, a variable valve timing mechanism, and the like (not shown). A signal is being output. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the engine rotational speed Ne, based on a crank position from a crank position sensor (not shown).

  The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 includes signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotation angle sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and motors detected by current sensors. Phase currents Iv and Iw applied to MG1 and MG2 are input, and a switching control signal to inverters 41 and 42 is output from motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotation angle sensors 43 and 44.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. In the battery ECU 52, signals necessary for managing the battery 50, for example, the voltage Vb between the terminals from the voltage sensor 51a installed between the terminals of the battery 50, the current attached to the output terminal on the positive side of the battery 50 The charge / discharge current Ib from the sensor 51b, the battery temperature Tb from the temperature sensor 51c attached to the battery 50, and the like are input, and data on the state of the battery 50 is communicated to the hybrid electronic control unit 70 as necessary. Output. Further, in order to manage the battery 50, the battery ECU 52 sets the storage ratio SOC as a ratio to the total capacity of the storage amount that can be discharged from the battery 50 based on the integrated value of the charge / discharge current Ib detected by the current sensor 51b. The input / output limits Win and Wout that are the maximum allowable power that may charge / discharge the battery 50 are calculated based on the calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limiting limit are set based on the storage ratio SOC of the battery 50. It can be set by setting a correction coefficient and multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient. FIG. 2 shows an example of the relationship between the battery temperature Tb and the basic values of the input / output limits Win and Wout, and FIG. 3 shows an example of the relationship between the storage ratio SOC and the correction coefficient. Here, as shown in FIG. 3, when the storage ratio SOC is equal to or higher than a predetermined ratio (for example, 80%), the input restriction correction coefficient is 0. Therefore, the basic value is multiplied by the input restriction correction coefficient. The set input limit Win is 0, and charging of the battery 50 is prohibited.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81 and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution and integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1, MG2 are controlled so that the required power is output to the ring gear shaft 32a with the operation of the engine 22. Both can be considered as the engine operation mode.

  In the engine operation mode, the hybrid electronic control unit 70 sets the required torque Tr * to be output to the ring gear shaft 32a based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. . Subsequently, the set required torque Tr * is multiplied by the rotation speed Nr of the ring gear shaft 32a (for example, the rotation speed obtained by multiplying the rotation speed Nm2 of the motor MG2 or the vehicle speed V by a conversion factor). The engine 22 is calculated by calculating the power Pdrv and subtracting the charge / discharge required power Pb * (positive value when discharged from the battery 50) of the battery 50 from the calculated traveling power Pdrv based on the storage ratio SOC of the battery 50. The required power Pe * as the power to be output from is set. Then, the target rotational speed Ne of the engine 22 is obtained using an operation line (for example, a fuel efficiency optimal operation line) as a relationship between the rotational speed Ne of the engine 22 and the torque Te that can efficiently output the required power Pe * from the engine 22. * And target torque Te * are set, and the motor is controlled by rotational speed feedback control so that the rotational speed Ne of the engine 22 becomes the target rotational speed Ne * within the range of the input / output limits Win and Wout of the battery 50. A torque command Tm1 * as a torque to be output from MG1 is set, and a torque acting on ring gear shaft 32a via power distribution and integration mechanism 30 when motor MG1 is driven by torque command Tm1 * is reduced from required torque Tr *. Set the torque command Tm2 * of the motor MG2, and set the target rotational speed Ne * and the target torque T * Send to engine ECU24 for capital, the torque command Tm1 *, the Tm2 * is sent to the motor ECU 40. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te *, controls the intake air amount, fuel injection control, and ignition of the engine 22 so that the engine 22 is operated by the target rotational speed Ne * and the target torque Te *. The motor ECU 40 that performs control or the like and receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  In the motor operation mode, the hybrid electronic control unit 70 sets the torque command Tm1 * of the motor MG1 to 0 and outputs the required torque Tr * to the ring gear shaft 32a within the range of the input / output limits Win and Wout of the battery 50. Then, torque command Tm2 * of motor MG2 is set and transmitted to motor ECU 40. Then, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  In the hybrid vehicle 20 of the embodiment, the motor ECU 40 selects one control mode from a plurality of control modes based on the rotational speeds Nm1, Nm2 of the motors MG1, MG2 and the torque commands Tm1 *, Tm2 *, respectively. The inverters 41 and 42 are subjected to switching control so that the motors MG1 and MG2 are driven. FIG. 5 shows an example of a control mode setting map for the motor MG2. In the figure, as indicated by solid lines, sinusoidal phase voltage commands Vu, Vv with an amplitude equal to or smaller than the amplitude of the triangular wave in pulse width modulation (PWM) control by triangular wave comparison in order from the region where the rotational speed and torque are small to large. , Vw is generated and converted into a sine wave control mode in which the inverter is switched with a PWM signal as a pseudo three-phase AC voltage, and sinusoidal voltage commands Vu, Vv, Vw are generated with an amplitude exceeding the amplitude of the triangular wave. The overmodulation control mode for switching the inverter with the PWM signal as the converted overmodulation voltage and the rectangular wave control mode for switching the inverter with a rectangular wave voltage having a voltage phase corresponding to the torque command are selected in advance. Yes. Therefore, the motor MG2 can be driven with high responsiveness by using the sine wave control mode in the region of low rotation speed and low torque, and the inverter 42 can be driven by using the rectangular wave control mode in the region of high rotation speed and high torque. Output higher torque by increasing the modulation factor (increase in the order of sine wave control mode, overmodulation control mode, and rectangular wave control mode), which is the ratio of output voltage (amplitude of fundamental wave component) to input voltage to It is possible to reduce the switching loss of the inverter 42 and the like. The control mode of motor MG1 is similarly determined.

  Further, in the hybrid vehicle 20 of the embodiment, the drive control of the motor MG2 is performed according to the control block illustrated in FIG. First, the motor ECU 40 sets the d-axis and q-axis current commands Id * and Iq * using the current command table 61 in which the relationship of the current command corresponding to the torque command is determined based on the torque command Tm2 *. Differences ΔId and ΔIq between the set current commands Id * and Iq * and feedback currents Id and Iq obtained for current feedback are calculated by the adders 62d and 62q, and the voltage command is based on the calculated differences ΔId and ΔIq. Voltage commands Vd and Vq are generated by the converters 63d and 63q. Subsequently, using the rotation angle θ of the motor MG2 detected by the rotation angle sensor 44, the coordinate converter 64 applies the two-phase / three-phase conversion to the voltage commands Vd, Vq to generate the phase voltage commands Vu, Vv, Vw. The PWM converter 66 generates a pulse width modulation signal based on the phase voltage commands Vu, Vv, Vw. Then, DC power is applied to the motor MG2 as three-phase AC power by switching the transistor of the inverter 42 based on the generated pulse width modulation control signal. Feedback currents Id and Iq obtained for current feedback are converted into three-phase two-phase currents Iv and Iw obtained from the current sensors 46V and 46W by the coordinate converter 68 using the rotation angle θ from the rotation angle sensor 44. Generate by applying transformation. Here, the motor MG2 performs field-weakening control in order to prevent the back electromotive force generated as the rotational speed (vehicle speed V) increases from exceeding the voltage input to the inverter 42 and unable to output the required torque. It is. This field weakening control is performed by applying a current to the d-axis in order to weaken the field force. The motor MG1 is also driven and controlled using the same control block as that shown in FIG.

  Next, it is detected by the rotation angle sensor 44 during the operation of the hybrid vehicle 20 of the embodiment, in particular, during the drive control of the motor MG2 so that no torque is output from the motor MG2, that is, the current flows only in the d-axis. The operation for correcting the rotation angle θ of the motor MG2 will be described. This routine is repeatedly executed at a predetermined time (for example, every several msec).

  When the rotation angle correction routine is executed, the CPU of the motor ECU 40 determines the accelerator opening Acc, the vehicle speed V, the input limit Win of the battery 50, the charge / discharge current Ib, the rotation angle θ of the motor MG2 from the rotation angle sensor 44, and the like. A process of inputting data is executed (step S100). Here, the accelerator opening degree Acc and the vehicle speed V are detected by the accelerator pedal position sensor 84 and the vehicle speed sensor 88 and input from the hybrid electronic control unit 70 by communication. The input limit Win is set based on the battery temperature Tb and the power storage ratio SOC and is input by communication by the battery ECU 52. The charge / discharge current Ib is detected by the current sensor 51b and input from the battery ECU 52 by communication.

  Subsequently, the input limit Win that has been input is 0 kW, that is, whether or not charging of the battery 50 is prohibited (step S110), and the vehicle speed V is weaker than a predetermined vehicle speed (for example, 100 km / h, etc.) Vref that requires field control. Whether it is larger (step S120), whether the accelerator opening Acc is smaller than a predetermined opening (for example, 10%) Aref that can be regarded as accelerator off (step S130), and the charge / discharge current Ib of the battery 50 is 0. Or less, that is, whether or not the battery 50 is charged (step S140), and whether or not the current control mode is the rectangular wave control mode (step S150). If any of the determinations in steps S110 to S150 is negative, this routine is terminated without correcting the rotation angle θ. On the other hand, when all of the determinations in steps S110 to S150 are positive, a negative current Id is supplied to the d-axis and no current is supplied to the q-axis (that is, no torque is output from the motor MG2). ), When the motor MG2 is controlled, it is determined whether the rotation direction of the motor MG2 is the normal rotation direction or the reverse rotation direction (step S160). When the rotation direction of the motor MG2 is the forward rotation direction, a negative value −β is set to the correction angle Δθ (step S170), and when the rotation direction of the motor MG2 is the reverse rotation direction, a positive value β is set to the correction angle Δθ. Then, the rotation angle θ is corrected by adding the set correction angle Δθ to the input rotation angle θ (step S190), and this routine is terminated.

  FIG. 7 is an explanatory diagram illustrating a state in which the rotation angle θ from the rotation angle sensor 44 used for control is corrected when the motor MG2 is controlled so that a negative current Id flows through the d-axis and no current flows through the q-axis. It is. FIG. 7A shows a state of correction when the motor MG2 is rotating forward, and FIG. 7B shows a state of correction when the motor MG2 is reversely rotated. Consider a case where the rotation angle θ from the rotation angle sensor 44 includes an offset error α in the normal rotation (plus) direction during the normal rotation of the motor MG2. In this case, even if the motor MG2 is controlled so that a negative current flows only in the d axis, the direction of the vector of the current that actually flows in the motor MG2 is shifted from the d axis to the forward rotation side by an angle α on the dc axis. Direction. Therefore, considering the original correct d-axis and q-axis as a reference, the motor MG2 not only has a negative current flowing through the d-axis, but also has a negative current flowing through the q-axis. Directional torque is output. In this case, when the motor MG2 is rotating forward, the direction of rotation and the direction of torque are reversed, so the motor MG2 is regenerated. In the embodiment, during the normal rotation of the motor MG2, a value −β obtained by adding a minus sign to the error α is set as the correction angle Δθ to correct the rotation angle θ, thereby generating a negative current in the q axis. This prevents the motor MG2 from regenerating unintentionally. Here, in the embodiment, the value −β is set to a value slightly larger than the design maximum error with respect to the origin of the rotation angle sensor 44. Therefore, even if the design error is included in the rotation angle sensor 44, current flows only in the d-axis based on the rotation angle θ obtained by correcting the rotation angle θ from the rotation angle sensor 44 with the correction angle Δθ. When the motor MG2 is controlled, no negative current flows through the q-axis, and the motor MG2 does not regenerate. Next, consider the case where the rotation angle θ from the rotation angle sensor 44 includes an offset error −α in the reverse (minus) direction during the reverse rotation of the motor MG2. In this case, even if the motor MG2 is controlled so that a negative current flows only in the d-axis, the direction of the vector of the current actually flowing in the motor MG2 is shifted from the d-axis to the reverse side by an angle α with the direction on the dc-axis. Become. For this reason, considering the original correct d-axis and q-axis as a reference, not only a negative current flows through the d-axis but also a positive current flows through the q-axis through the motor MG2. Torque is output. In this case, when the motor MG2 is reversely rotated, the direction of rotation and the direction of torque are reversed, so the motor MG2 is regenerated. In the embodiment, during the reverse rotation of the motor MG2, a positive current is generated on the q axis by correcting the rotation angle θ by setting the correction angle Δθ to a value β obtained by adding a minus sign to the error −α. This prevents the motor MG2 from regenerating unintentionally. When the rotation angle sensor 44 includes an offset error in the reverse direction during forward rotation of the motor MG2 (that is, when the motor MG2 is controlled so that current flows only in the d axis, current in the positive direction is applied to the q axis. When the motor MG2 is running and when the motor MG2 is reversely rotated, or when the rotation angle sensor 44 includes an offset error in the forward direction (that is, when the motor MG2 is controlled so that current flows only in the d-axis). Similarly, when the motor MG2 is powered by a negative current flowing in the q-axis), the rotation angle θ is similarly corrected, and thus the motor MG2 outputs torque that promotes power running. Is a slight amount corresponding to the error of the rotation angle sensor 44, so no problem occurs.

  Next, the operation of correcting the phase currents Iv and Iw detected by the current sensors 46V and 46W during the drive control of the motor MG2 so that no torque is output from the motor MG2, that is, the current flows only in the d-axis. Will be described. FIG. 8 is a flowchart illustrating an example of a phase current correction routine executed by the motor ECU 40. This routine is repeatedly executed at a predetermined time (for example, every several msec).

  When the phase current correction routine is executed, the CPU of the motor ECU 40 determines the accelerator opening Acc, the vehicle speed V, the input limit Win of the battery 50, the charge / discharge current Ib, the phase currents Iv and Iw from the current sensors 46V and 46W, and the like. A process of inputting data is executed (step S200). continue,

  Subsequently, similarly to steps S110 to S150 of the rotation angle correction routine of FIG. 6, whether or not the input input limit Win is 0 kW (step S210), and whether or not the vehicle speed V is higher than the predetermined vehicle speed Vref (step S220). Whether the accelerator opening Acc is smaller than the predetermined opening Aref (step S230), whether the charge / discharge current Ib of the battery 50 is smaller than 0 (step S240), the current control mode is rectangular wave control It is determined whether or not the mode is selected (step S250). If any of the determinations in steps S210 to S250 is negative, the gain kv that is the correction gain for the current sensor 46V and the gain kw that is the correction gain for the current sensor 46W are respectively determined in advance. A value k is set (step S260). On the other hand, when all of the determinations in steps S210 to S250 are positive, it is determined whether the rotation direction of motor MG2 is the normal rotation direction or the reverse rotation direction (step S270). When the rotation direction of the motor MG2 is the forward rotation direction, the gain kv obtained by adding the value k to the correction value Δk and the gain kw obtained by subtracting the correction value Δk from the value k are set (step S280). When the rotation direction of the motor MG2 is the reverse rotation direction, a value obtained by subtracting the correction value Δk from the value k is set as the gain kv, and a value obtained by adding the correction value Δk to the value k is set (step S290). Then, the input phase current Iv multiplied by the gain kv is set as the phase current Iv used for control, and the input phase current Iw multiplied by the gain kw is set as the phase current Iw used for control (step) S300), this routine is finished. When the control phase currents Iv and Iw are set, when steps S210 to S250 are established, a negative current flows through the d-axis and no current flows through the q-axis (that is, the motor MG2). Current command Id *, Iq * is set so as to prevent torque from being output, and the control phase currents Iv, Iw are coordinate-transformed to generate feedback currents Id, Iq, and current commands Id *, Iq * The motor MG2 is controlled by feedback control based on the feedback currents Id and Iq.

  FIG. 9 is an explanatory diagram showing current vectors when coordinate conversion is performed in a state where gain errors are included in the phase currents Iv and Iw from the current sensors 46V and 46W. FIG. 9A shows a state when the motor MG2 is rotating forward, and FIG. 9B shows a state when the motor MG2 is rotating backward. Consider a case where the motor MG2 is rotating forward. When a negative value is set for the current command Id * and a value 0 is set for the current command Iq *, the phase currents Iv, detected by the current sensors 46V, 46W are detected if the current sensors 46V, 46W do not include a gain error. When the motor MG2 is controlled by current feedback control based on the deviation between the feedback currents Id and Iq obtained by converting the coordinates of Iw and the current commands Id * and Iq *, a negative current flows only in the d-axis. However, if a negative gain error is included in the V-phase current sensor 46V and a positive gain error is included in the W-phase current sensor 46W, as shown in FIG. In addition to a negative current flowing in the d-axis, a negative current also flows in the q-axis, and a negative torque is output from the motor MG2. In this case, when the motor MG2 is rotating forward, the direction of rotation and the direction of torque are reversed, so the motor MG2 is regenerated. In the embodiment, during the forward rotation of the motor MG2, the V-phase current Iv is gain-corrected to the plus side and the W-phase phase current Iw is gain-corrected to the minus side, thereby generating a current in the negative direction on the q-axis. This prevents the motor MG2 from regenerating unintentionally. Next, consider the case where the motor MG2 is rotating in reverse. Also in this case, if the current command Id * is set to a negative value, the current command Iq * is set to 0 and the motor MG2 is subjected to current feedback control, if the current sensors 46V and 46W do not include a gain error, d Negative current flows only through the shaft. However, if the V-phase current sensor 46V includes a plus-side gain error and the W-phase current sensor 46W includes a minus-side gain error, as shown in FIG. In addition to a negative current flowing in the d-axis, a positive current flows in the q-axis, and a positive torque is output from the motor MG2. In this case, when the motor MG2 is reversely rotated, the direction of rotation and the direction of torque are reversed, so the motor MG2 is regenerated. In the embodiment, during the reverse rotation of the motor MG2, the V-phase current Iv is gain-corrected to the minus side and the W-phase phase current Iw is gain-corrected to the plus side, thereby generating a positive current on the q axis. This prevents the motor MG2 from regenerating unintentionally. Similar to the correction of the rotation angle θ described above, the gain errors of the current sensors 46V and 46W can occur in both positive and negative directions. Therefore, depending on the direction of the gain error, if the gain correction is performed, the motor MG2 Although torque that promotes power running may be output, there is no problem because the gain correction is a slight amount corresponding to the error of the current sensors 46V and 46W.

  According to the hybrid vehicle 20 of the embodiment described above, when the motor MG2 is controlled such that a negative current flows in the d-axis and no current flows in the q-axis, the rotation angle sensor 44 used for control is used. Is corrected in the reverse direction when the motor MG2 is rotating forward, and is corrected in the forward direction when the motor MG2 is rotating reversely, so that the control of the motor MG2 is corrected in a direction from regeneration to power running. Thus, even if the rotation angle sensor 44 includes an offset error, by controlling the motor MG2 based on the corrected rotation angle θ, no current in the direction opposite to the rotation direction of the motor MG2 flows through the q axis. That is, the regenerative torque can be prevented from being output. As a result, it is possible to prevent the motor MG2 from regenerating unexpectedly and to more reliably prevent the battery 50 from being overcharged.

  Further, according to the hybrid vehicle 20 of the embodiment, when the motor MG2 is controlled so that a negative current flows in the d-axis and no current flows in the q-axis, the current sensor 46V is used during the normal rotation of the motor MG2. The V-phase current Iv from the current sensor 46W is gain-corrected to the plus side, and the W-phase phase current Iw from the current sensor 46W is gain-corrected to the minus side. By correcting the gain of Iv to the minus side and correcting the gain of the W-phase phase current Iw from the current sensor 46W to the plus side, the phase currents Iv and Iw are corrected in the direction from the regeneration to the power running. Therefore, even if the current sensors 46V and 46W include a gain error, the motor MG2 is controlled based on the corrected phase currents Iv and Iw. More, no reverse current flows in the rotational direction of the motor MG2 to the q-axis, i.e., the regenerative torque can be prevented from being outputted. As a result, it is possible to prevent the motor MG2 from regenerating unexpectedly and to more reliably prevent the battery 50 from being overcharged.

  In the hybrid vehicle 20 of the embodiment, control is performed so that torque is not output from the motor MG2 by setting the current command Id * so that the negative current Id flows in the d axis. The current command Id * may be set so that Id flows. At this time, in the case of correcting the rotation angle θ from the rotation angle sensor 44 used for control, the motor MG2 may be corrected in the forward direction when the motor MG2 is rotated forward, and may be corrected in the reverse direction when the motor MG2 is rotated backward. When the phase currents Iv and Iw from the current sensors 46V and 46W used for the control are corrected, the gain of the V-phase phase current Iv is corrected to the negative side and the W-phase phase current Iw is corrected during the forward rotation of the motor MG2. The gain is corrected to the plus side, and when the motor MG2 is reversely rotated, the V-phase current Iv is corrected to the plus side and the W-phase phase current Iw is corrected to the minus side.

  In the hybrid vehicle 20 of the embodiment, both the correction for the rotation angle θ from the rotation angle sensor 44 and the correction for the phase currents Iv and Iw from the current sensors 46V and 46W are executed, but only one of them is executed. Correction may be executed.

  In the hybrid vehicle 20 of the embodiment, the V-phase current Iv from the current sensor 46V that detects the current flowing through the V-phase coil of the motor MG2 and the W-phase phase from the current sensor 46W that detects the current flowing through the W-phase coil. The current Iw is used to generate feedback currents Id and Iq to control the motor MG2. However, the present invention is not limited to this, and a current sensor is attached to each of the U-phase coil and the V-phase coil of the motor MG2. The motor MG2 may be controlled using the U-phase phase current Iu detected by the U-phase current sensor and the V-phase current Iv detected by the V-phase current sensor, or the U of the motor MG2 may be controlled. A current sensor is attached to each of the phase coil and the W phase coil, and the U phase current Iu and the W phase current sensor detected by the U phase current sensor. It may be controlled the motor MG2 using the phase current Iw of W-phase to be detected more. In FIG. 10, when any two currents of the U phase, V phase, and W phase of the motor MG2 are detected by the sensor, the motor rotation direction that the motor MG2 regenerates and the gain error included in the detected current value of each phase are shown. A combination with a code is shown. Here, the combination of the embodiment in which the V-phase phase current Iv and the W-phase phase current Iw are used for controlling the motor MG2 corresponds to the combination “2” in FIG. When MG2 reverses, the combination of “5” in the figure corresponds. Note that each of the combinations in FIG. 10 shows a case in which a negative current flows through the d-axis. When a positive current flows through the d-axis, the sign of the q-axis current is reversed and the gain correction is performed. The direction is also reversed. The combination in which the U-phase phase current Iu and the V-phase phase current Iv are used to control the motor MG2 is such that when the motor MG2 rotates forward, the U-phase phase current Iu includes a negative gain error. When the phase current Iv includes a plus-side gain error, even if the motor MG2 is controlled by current feedback control so that a current flows in the d-axis and no current flows in the q-axis, a current in the negative direction is present in the q-axis. The motor MG2 is regenerated (see “1” in FIG. 10), and when the motor MG2 reverses, a positive gain error is included in the U-phase phase current Iu and a negative gain is added to the V-phase current Iv. When an error is included, even if the motor MG2 is controlled by current feedback control so that a current flows in the d-axis and no current flows in the q-axis, a positive current flows in the q-axis and the motor MG2 is regenerated ( Refer to "4" in the 10). Therefore, when the motor MG2 is rotating forward, the U-phase phase current Iu is gain-corrected to the plus side and the V-phase phase current Iv is gain-correcting to the minus side, and when the motor MG2 is rotating reversely, the U-phase phase current Iu is It is only necessary to correct the gain to the minus side and to correct the V-phase current Iv to the plus side. Further, the combination in which the U-phase phase current Iu and the W-phase phase current Iw are used for controlling the motor MG2 includes a positive-side gain error in the U-phase phase current Iu when the motor MG2 is rotating forward. When the phase phase current Iw includes a negative gain error, even if the motor MG2 is controlled by current feedback control so that the current flows in the d-axis and does not flow in the q-axis, The current flows and the motor MG2 is regenerated (see “3” in FIG. 10). When the motor MG2 is rotated in reverse, the U-phase phase current Iu includes a minus-side gain error, and the W-phase phase current Iw is plus. When the motor MG2 is controlled by current feedback control so that a current flows in the d-axis and no current flows in the q-axis, a positive current flows in the q-axis and the motor MG2 is regenerated. That (see "6" in FIG. 10). Therefore, when the motor MG2 is rotating forward, the U-phase phase current Iu is gain-corrected to the minus side and the W-phase phase current Iw is gain-correcting to the plus side, and when the motor MG2 is rotating reversely, the U-phase phase current Iu is It is only necessary to correct the gain to the plus side and to correct the gain of the W-phase current Iw to the minus side.

  In the hybrid vehicle 20 of the embodiment, as a condition for correcting the rotation angle θ from the rotation angle sensor and the phase current from the current sensor, whether or not the input limit Win is 0 kW or not and the vehicle speed V is higher than the predetermined vehicle speed Vref. Whether or not the accelerator is off, whether or not the charge / discharge current Ib of the battery 50 is smaller than the value 0, and whether or not the current control mode is the rectangular wave control mode. Of these conditions, some or all of the other conditions except the condition where the input restriction Win is 0 kw may be omitted. Further, instead of determining whether or not the input limit Win is 0 kW, it may be directly determined whether or not the power storage rate SOC is equal to or higher than a predetermined rate at which charging of the battery 50 is prohibited.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. 11, the power of the motor MG2 is connected to the drive shaft. It may be connected to an axle (an axle connected to the wheels 39c and 39d in FIG. 11) different from the axle (the axle to which the drive wheels 39a and 39b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the drive shaft connected to the drive wheels 39a and 39b via the power distribution and integration mechanism 30, but the hybrid vehicle 220 of the modified example of FIG. As illustrated, the engine 22 includes an inner rotor 232 connected to the crankshaft of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 39a and 39b. A counter-rotor motor 230 that transmits power to the drive shaft and converts remaining power into electric power may be provided.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft connected to the drive wheels 39a and 39b via the power distribution and integration mechanism 30, and the power from the motor MG2 is output to the drive shaft. However, as illustrated in the hybrid vehicle 320 of the modification of FIG. 13, the motor MG is attached to the drive shaft connected to the drive wheels 39a and 39b via the transmission 330, and the clutch 329 is attached to the rotation shaft of the motor MG. The power from the engine 22 is output to the drive shaft via the rotating shaft of the motor MG and the transmission 330, and the power from the motor MG is output to the drive shaft via the transmission 330. It may be output. Alternatively, as illustrated in the hybrid vehicle 420 of the modified example of FIG. 14, the power from the engine 22 is output to the drive shaft connected to the drive wheels 39a and 39b via the transmission 430 and the power from the motor MG is output. It may be output to an axle different from the axle to which the drive wheels 39a, 39b are connected (the axle connected to the wheels 39a, 39b in FIG. 14). In other words, any type of hybrid vehicle may be used as long as it includes an engine and an electric motor that outputs driving power.

  In the embodiment, the present invention has been described as the form of the hybrid vehicle 20, but an electric vehicle including only a motor may be used as a driving power source, or a vehicle other than the vehicle may be used.

  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 motor MG2 corresponds to a “motor”, the battery 50 corresponds to a “secondary battery”, the rotation angle sensor 44 and the current sensors 46V and 46W correspond to “state detection sensors”, and a torque command Tm2 *. The d-axis and q-axis current commands Id * and Iq * are set based on the difference between the set current commands Id * and Iq * and the feedback currents Id and Iq obtained for current feedback by the difference ΔId and ΔIq. The motor ECU 40 that performs switching control of the inverter 42 by feedback control based on this corresponds to “control means”, and the motor ECU 40 that executes the rotation angle correction routine of FIG. 6 and the phase current correction routine of FIG. 8 corresponds to “detection value correction means”. To do. Here, the “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor that can output power for traveling, such as an induction motor. I do not care. In addition, the “secondary battery” is not limited to the lithium ion secondary battery, and may be any type of secondary battery such as a nickel-hydrogen secondary battery. The “state detection sensor” is not limited to the rotation angle sensor 44 and the current sensors 46V and 46W, and any sensor may be used as long as it detects the state of the motor used for controlling the motor. .

  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 electric vehicles.

  20, 120, 220, 320 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 Carrier, 35 Reduction gear, 37 Gear mechanism, 38 Differential gear, 39a, 39b Drive wheel, 39c, 39d Wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation angle sensor, 50 Battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 battery electronic control unit (battery ECU), 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 0 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 90 Brake master cylinder, 92 Brake actuator, 94 Brake electronics Control unit (brake ECU), 96a-96d Brake wheel cylinder, 230 rotor motor, 232 inner rotor, 234 outer rotor, 329 clutch, 330, 430 transmission, MG, MG1, MG2 motor.

Claims (6)

An electric motor capable of inputting / outputting driving power; a secondary battery capable of exchanging electric power with the electric motor; a state detection sensor for detecting a state of the electric motor; a required torque required for the electric motor; And an electric vehicle comprising control means for controlling the electric motor based on the state,
When the storage ratio of the secondary battery is equal to or higher than a predetermined ratio, the detection unit includes a detection value correction unit that corrects the detection value detected by the state detection sensor in a direction from regeneration to power running. Electric vehicle. The electric vehicle according to claim 1,
The state detection sensor is a rotation angle detection sensor that detects a rotation angle of the electric motor,
The control means sets a d-axis current command and a q-axis current command in a dq coordinate system based on the rotation angle of the motor based on the required torque, and based on the set current commands. Means for controlling the electric motor,
The detected value correcting means is means for correcting the detected rotation angle of the electric motor in a direction in which the control of the electric motor moves from regeneration to power running. The electric vehicle according to claim 1 or 2,
The electric motor is a three-phase AC electric motor,
The state detection sensor is a phase current detection sensor that detects a phase current of the electric motor,
The control means sets a d-axis current command and a q-axis current command in the dq coordinate system based on the required torque, and a d-axis current obtained from the d-axis current command and the phase current. The d-axis voltage command is set by feedback control based on deviation, and the q-axis voltage command is set by feedback control based on deviation between the q-axis current command and the q-axis current obtained by the phase current, Means for controlling the electric motor based on each set voltage command;
The detected value correcting means is means for correcting the detected phase current so that the control of the electric motor is directed from regeneration to power running.   The detection value correcting means is means for correcting the detection value detected by the state detection sensor when the secondary battery is charged in a direction in which the control of the electric motor is directed from regeneration to power running. The electric vehicle according to any one of claims 1 to 3.   The detection value correction means is means for correcting the detection value detected by the state detection sensor when the vehicle speed is equal to or higher than a predetermined vehicle speed in a direction in which the control of the electric motor is directed from regeneration to power running. The electric vehicle according to any one of 1 to 4. An electric vehicle according to any one of claims 1 to 5,
The control means is means for controlling the electric motor by switching a plurality of control modes including rectangular wave control and sine wave control,
The detection value correction means is a means for correcting the detection value detected by the state detection sensor when the electric motor is controlled by the rectangular wave control in a direction in which the electric motor control is directed from regeneration to power running. An electric vehicle characterized by

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