JP2006094669A - Drive control device for electromotive vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive control device for an electromotive vehicle capable of detecting the abnormality of a temperature-detecting means, while preventing a malfunction of a motor. <P>SOLUTION: The drive control device 1 for an electromotive vehicle decides target torque and supplies AC power to a motor coil, to generate the target torque to drive and control a drive motor 2. The device 1 detects the temperature of the drive motor 2 and estimates the voltage value applied to the motor coil based on the detected temperature of the drive motor 2, the value of the current flowing to the motor coil and a map showing the correlation between the temperature and the resistance value of the motor coil. The drive control device 1 for an electromotive vehicle detects the voltage applied to the motor coil and detects the malfunction of a motor temperature detecting part 17 when the difference between the detected voltage value and the estimated voltage value is larger than a specified value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive control device for an electric vehicle.

Conventionally, as shown in Patent Document 1, a technique for determining that a disconnection has occurred in a signal system of a temperature detection means is known. According to this technique, the temperature of the motor is estimated by integrating the torque command value over time, and the temperature detected by the temperature detection means indicates a low temperature despite the estimated temperature being sufficiently high. It is determined that a disconnection has occurred in the signal system of the detection means (see Patent Document 1).
Japanese Patent Laid-Open No. 7-31802

  However, according to the prior art, since the motor temperature must be estimated by integrating the torque command value over time, the signal system of the temperature detection means is disconnected unless an operation that provides a predetermined amount of heat is performed. Cannot be detected. Therefore, in the prior art, when detecting the disconnection of the signal system, there is a possibility that the operation is performed such that the motor temperature is raised despite the high temperature of the motor, which may cause a motor failure.

  The present invention has been made to solve such a conventional problem. The object of the present invention is to detect a failure of the temperature detecting means while preventing the motor from being damaged. An object is to provide a drive control device for an electric vehicle.

  The drive control apparatus for an electric vehicle according to the present invention determines a target torque and supplies AC power to a motor coil to control the drive motor so as to generate the target torque. The apparatus includes temperature detection means for detecting the temperature of the drive motor and voltage estimation means. The voltage estimation means estimates the voltage value applied to the motor coil based on the temperature of the drive motor detected by the temperature detection means, the value of the current flowing in the motor coil, and the correlation between the temperature and the resistance value of the motor coil. . On the other hand, the drive control device for an electric vehicle has voltage detection means for detecting a voltage applied to the motor coil. Further, the drive control device for the electric vehicle detects that the temperature detecting means has failed when the difference between the voltage value estimated by the voltage estimating means and the voltage value detected by the voltage detecting means is a predetermined value or more. To detect.

  According to the present invention, the voltage value applied to the motor coil is determined based on the correlation between the temperature of the drive motor detected by the temperature detection means, the value of the current flowing in the motor coil, and the resistance value of the motor coil. presume. That is, since the resistance value of the motor coil changes depending on the temperature, the resistance value of the motor coil is obtained from the temperature and correlation of the drive motor detected by the temperature detecting means, and from the resistance value and the value of the current flowing in the motor coil. The voltage value is estimated.

  Further, the voltage applied to the motor coil is detected by the voltage detecting means, and this is compared with the estimated voltage value. Here, the estimated voltage value is close to the original value, that is, the voltage value detected by the voltage detection means, unless the temperature detection means has failed. On the other hand, if the temperature detecting means is out of order, the detected temperature becomes an abnormal value, and the resistance value of the motor coil also becomes an abnormal value, so that the estimated voltage also becomes an abnormal value.

  For this reason, when the difference between the voltage values is equal to or greater than a predetermined value, it can be detected that the temperature detecting means is out of order. As described above, according to the present invention, it is possible to determine the failure of the temperature detecting means without performing an operation for increasing the motor temperature despite the high temperature of the motor. Therefore, it is possible to detect the failure of the temperature detecting means while preventing the motor from being damaged.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. In the drawings, the same or similar elements are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 1 is a configuration diagram of a drive control device for an electric vehicle according to an embodiment. The drive control apparatus 1 for an electric vehicle shown in FIG. 1 determines a target torque and supplies AC power to a motor coil to drive the drive motor 2 so as to generate the target torque. In addition to the drive motor 2, the electric vehicle drive control device 1 includes a target torque calculation unit (control unit) 10, a current command value calculation unit (current command value calculation unit) 11, a motor current detection unit (current detection unit). ) 12, a voltage command value calculation unit 13, a drive motor drive unit 14, and a rotation number detection unit (rotation number detection means) 15.

  The target torque calculation unit 10 calculates a target torque by inputting signals indicating the accelerator opening and the vehicle speed. The current command value calculation unit 11 calculates current values (hereinafter referred to as command current values) Iq * and Id * to be applied to the motor coil of the drive motor 2 in order to generate the target torque calculated by the target torque calculation unit 10. Is.

  The motor current detection unit 12 detects values (hereinafter referred to as actual current values) Iu, Iv, and Iw flowing through the motor coil of the drive motor 2. The voltage command value calculation unit 13 is based on the command current values Iq * and Id * calculated by the current command value calculation unit 11 and the actual current values Iu, Iv and Iw detected by the motor current detection unit 12. 2 to calculate a voltage value (hereinafter referred to as a command voltage value) to be applied. That is, the voltage command value calculation unit 13 is configured to obtain a command voltage value that matches the command current value and the actual current value.

  The drive motor drive unit 14 drives the drive motor 2 by PWM control so that the voltage applied to the drive motor 2 matches the voltage command value. The rotation speed detection unit 15 detects the rotation speed of the drive motor 2 and includes, for example, a rotary encoder.

  FIG. 2 is a configuration diagram illustrating details of the current command value calculation unit 11 illustrated in FIG. 1. As shown in the figure, the current command value calculation unit 11 includes an Iq * map unit 11a and an Id * map unit 11b. The Iq * map unit 11a stores a map indicating the correlation between torque and angular velocity and q-axis current. Further, the Iq * map unit 11a is configured to input a target torque signal and an angular velocity signal ω of the drive motor 2. Therefore, the Iq * map unit 11a can obtain the q-axis current command value Iq * from the input signal and the stored map. Further, the Id * map unit 11b can store a map in the same manner to obtain the d-axis current command value Id *.

  FIG. 3 is a configuration diagram illustrating details of the voltage command value calculation unit 13 illustrated in FIG. 1. As shown in the figure, the voltage command value calculation unit 13 includes a three-phase / two-phase conversion unit 13a, a current control unit 13b, and a two-phase / three-phase conversion unit 13c.

  The three-phase / two-phase converter 13a inputs the actual current values Iu, Iv, Iw of the three-phase coil detected by the motor current detector 12, and converts them into actual currents Id, Iq on the dq axis. is there. The current control unit 13b inputs the current command values Iq * and Id * calculated by the current command value calculation unit 11 and the actual currents Id and Iq on the dq axis, and the difference between the two becomes “0”. Such control voltages Vd and Vq are output. The two-phase / three-phase converter 13c receives the control voltages Vd, Vq on the dq axis and converts them into three-phase voltages Vu, Vv, Vw.

  Reference is again made to FIG. In addition to the above configuration, the drive control apparatus 1 for an electric vehicle includes a motor voltage detection unit (voltage detection unit) 16, a motor temperature detection unit (temperature detection unit) 17, a voltage estimation unit (voltage estimation unit) 18, and a failure detection Part (failure detection means) 19 is provided. And this apparatus 1 detects the failure of the motor temperature detection part 17 by these structures. In the following embodiments, the failure of the motor temperature detection unit 17 includes failure states such as breakage, disconnection, and rare short of the motor temperature detection unit 17.

  The motor voltage detection unit 16 detects a voltage applied to the motor coil of the drive motor 2. The motor temperature detection unit 17 detects the temperature of the drive motor 2. The voltage estimation unit 18 estimates a voltage value applied to the motor coil, and stores a map indicating the correlation between the temperature and the resistance value of the motor coil. And the voltage estimation part 18 inputs the signal which shows the temperature of the drive motor 2 detected by the motor temperature detection part 17, and the signal which shows the value of the electric current which flows into a motor coil, and calculates the temperature and the resistance value of a motor coil. The voltage value applied to the motor coil is estimated based on the map indicating the correlation.

  Further, the voltage estimation unit 18 is connected to the rotation number detection unit 15 and is configured to input a motor rotation number signal from the rotation number detection unit 15. For this reason, the voltage estimation unit 18 is a map showing the correlation between the temperature of the drive motor 2 detected by the motor temperature detection unit 17, the value of the current flowing through the motor coil, and the resistance value of the motor coil. In addition, the voltage value applied to the motor coil is estimated based on the motor speed.

  The failure detection unit 19 determines whether or not the motor temperature detection unit 17 has failed. Specifically, the failure detection unit 19 detects that the motor temperature detection unit 17 has failed when the difference between the voltage value detected by the motor voltage detection unit 16 and the voltage value estimated by the voltage estimation unit 18 is greater than or equal to a predetermined value. Judge that

  FIG. 4 is a block diagram showing details of the motor temperature detection unit 17 shown in FIG. As shown in the figure, the motor temperature detection unit 17 includes a thermistor 17a, a power supply unit 17b, and two resistors 17c and 17d. The thermistor 17a is disposed adjacent to the drive motor 2, and has a characteristic that the resistance value increases as the temperature decreases. One end of the thermistor 17a is connected in series to the power supply unit 17b, and the other end is grounded.

  A first resistor 17c is interposed between the power supply unit 17b and the thermistor 17a. Further, the second resistor 17d is connected in series with the first resistor 17c, and is connected in parallel with the thermistor 17a. That is, one end of the second resistor 17d is connected to the connection point 17e between the thermistor 17a and the first resistor 17c, and the other end is grounded.

  Furthermore, the motor temperature detector 17 has an A / D converter 17f. The A / D converter 17f converts the voltage value at the connection point 17e into a digital value. The motor temperature detection unit 17 detects the temperature from the converted voltage value.

  FIG. 5 is a graph showing the characteristics of the thermistor 17a shown in FIG. In FIG. 5, the vertical axis indicates the resistance value (kΩ), and the horizontal axis indicates the temperature (deg). As shown in the figure, the resistance value of the thermistor 17a increases as the temperature decreases, and decreases as the temperature increases.

  FIG. 6 is a graph showing voltage values at the connection point 17e shown in FIG. In FIG. 6, the vertical axis indicates the voltage value (V), and the horizontal axis indicates the temperature (deg). As described above, the resistance value of the thermistor 17a decreases as the temperature increases. For this reason, as shown in the figure, the voltage value at the connection point 17e tends to decrease as the temperature rises during normal operation. The motor temperature detection unit 17 uses such characteristics to monitor the voltage value at the connection point 17e and refer to the map to detect the motor temperature.

  On the other hand, when an abnormality such as disconnection occurs in the thermistor 17a, the voltage value at the connection point 17e is kept constant. For this reason, the motor temperature detection unit 17 can detect, for example, the motor temperature only at about -25 degrees (specific temperature) at the time of failure, and cannot detect a temperature exceeding the specific temperature at the time of failure. The specific temperature depends on the characteristics of the thermistor 17a and the resistance values of the first and second resistors 17c and 17d, and is not particularly limited to about -25 degrees.

  FIG. 7 is a configuration diagram illustrating details of the voltage estimation unit 18 illustrated in FIG. 1. As shown in the figure, the voltage estimation unit 18 includes a voltage estimation map unit 18a. The voltage estimation map unit 18a stores a map indicating the correlation between the temperature and the resistance value of the motor coil. The voltage estimation map unit 18 a is configured to input information on the temperature of the drive motor 2 detected by the motor temperature detection unit 17. Further, the voltage estimation map unit 18a obtains the resistance value of the motor coil from the input temperature information and the above correlation map.

  The voltage estimation map unit 18a receives a signal indicating the value of the current flowing through the motor coil. The signal input here may be a detection value detected by the motor current detection unit 12, that is, an actual current value Iu, Iv, Iw, or a current command value obtained by the current command value calculation unit 11. Either Iq * or Id * may be used. The voltage estimation map unit 18a estimates the voltage value applied to the motor coil from the value of the current flowing through the motor coil and the resistance value of the motor coil obtained from the map.

  In addition, the voltage estimation map unit 18a inputs a signal indicating the motor rotation number detected by the rotation number detection unit 15. Here, when the drive motor 2 is driven, an induced voltage is generated in the motor coil. Therefore, the voltage estimation map unit 18a receives a signal indicating the motor rotational speed detected by the rotational speed detection unit 15, obtains an induced voltage, and estimates a voltage value applied to the motor coil. Then, the voltage estimation map unit 18a outputs the estimated voltages V0u, V0v, V0w.

  Next, the failure determination operation of the apparatus 1 will be described. FIG. 8 is a flowchart showing a failure determination process performed by the drive control device 1 for an electric vehicle according to the present embodiment.

  As shown in the figure, in step ST10, the failure detection unit 19 reads the motor voltage. Next, in step ST11, the voltage estimation unit 18 reads the motor current. At this time, the voltage estimation unit 18 reads either the detection values Iu, Iv, Iw of the motor current detection unit 12 or the current command values Iq *, Id * calculated by the current command value calculation unit 11.

  Next, in step ST12, the voltage estimation unit 18 reads a signal indicating the temperature detected by the motor temperature detection unit 17. In step ST13, the voltage estimation unit 18 estimates the voltage applied to the motor coil of the drive motor 2. Here, the voltage estimation unit 18 estimates the voltage applied to the motor coil of the drive motor 2 with reference to a map showing the correlation between the temperature and the resistance value of the motor coil.

  In step ST14, the failure detection unit 19 determines whether the difference between the voltage value estimated in step ST13 and the actual voltage value detected in step ST10 is equal to or greater than a predetermined value.

  Here, the voltage value estimated in step ST13 is close to the original value, that is, the voltage value detected by the motor voltage detection unit 16 in step ST10, unless the motor temperature detection unit 17 has failed. For this reason, when the difference between the voltage values is not equal to or greater than the predetermined value (ST14: NO), the failure detection unit 19 determines that the motor temperature detection unit 17 is normal as shown in step ST15. Then, the process returns to step ST10, and the process shown in FIG. 8 is repeated until the apparatus 1 is turned off.

  On the other hand, if the motor temperature detection unit 17 has failed, the detected temperature becomes an abnormal value, and the resistance value of the motor coil also becomes an abnormal value. For this reason, the estimated voltage also becomes an abnormal value. For this reason, when the difference between the voltage values is equal to or greater than a predetermined value (ST14: YES), the failure detection unit 19 detects that the motor temperature detection unit 17 has failed as shown in step ST16. Then, the process returns to step ST10, and the process shown in FIG. 8 is repeated until the apparatus 1 is turned off.

  In the process of step ST14 described above, it is determined that the difference is greater than or equal to a predetermined value, but the estimated voltage value of the voltage estimation unit 18 is smaller than the actual voltage value of the motor voltage detection unit 16 by a predetermined value or more. It may be determined whether or not.

  More specifically, first, the motor temperature detection unit 17 cannot detect a temperature exceeding a specific temperature at the time of failure as shown in FIG. Further, since the temperature exceeding the specific temperature cannot be detected, the resistance value of the motor coil calculated by the voltage estimation unit 18 is always a small value. For this reason, the voltage value estimated by the voltage estimation part 18 at the time of failure of the motor temperature detection part 17 will become low. Therefore, it is sufficient to determine whether or not the estimated voltage value of the voltage estimating unit 18 is smaller than the actual voltage value of the motor voltage detecting unit 16 by a predetermined value or more, and vice versa. That is, it is not necessary to make a determination when the actual voltage value is larger than the estimated voltage value. Therefore, unnecessary judgments can be reduced and the possibility of erroneous judgments can be reduced.

  Further, in the process shown in FIG. 8, the rotational speed of the drive motor 2 is not taken into account in the voltage estimation, but a signal indicating the rotational speed of the drive motor 2 detected by the rotational speed detection unit 15 is input and the voltage is May be estimated. Thereby, the voltage value applied to the motor coil can be estimated in consideration of the induced voltage.

  Next, a modification example of failure determination shown in FIG. 8 will be described. FIG. 9 is a flowchart showing a failure determination process by the drive control apparatus 1 for an electric vehicle according to the present embodiment, and shows a second process example. First, in the second processing example, the voltage estimation unit 18 reads the motor temperature detected by the motor temperature detection unit 17 in step ST20. At this time, the voltage estimation unit 18 transmits the read motor temperature information to the failure detection unit 19.

  In step ST21, the failure detection unit 19 determines whether or not the motor temperature exceeds a predetermined temperature. Here, when the motor temperature exceeds the predetermined temperature (ST21: YES), in step ST22, the failure detection unit 19 determines that the motor temperature detection unit 17 is normal. Next, the process returns to step ST20, and the process shown in FIG. 9 is repeated until the apparatus 1 is turned off.

  On the other hand, when the motor temperature does not exceed the predetermined temperature (ST21: NO), the process proceeds to step ST23. Thereafter, in steps ST23 to ST28, processing similar to the processing shown in steps ST10, ST11, ST13 to ST16 shown in FIG. 8 is performed.

  The process in step ST21 is provided for the following reason. First, the motor temperature detection unit 17 cannot detect a temperature exceeding a specific temperature at the time of failure as shown in FIG. For this reason, when the temperature exceeding the specific temperature can be detected by the motor temperature detection unit 17, it can be said that the motor temperature detection unit 17 is normal. Therefore, the failure detection unit 19 determines whether or not the motor temperature detected by the motor temperature detection unit 17 exceeds a predetermined temperature, that is, whether or not the specific temperature is lower than the specific temperature. A failure determination is made as to whether or not the temperature detector 17 has failed.

  Next, processing after a failure of the motor temperature detection unit 17 is detected in the drive control device 1 for an electric vehicle according to the present embodiment will be described. First, when the motor temperature detection unit 17 fails, the device 1 cannot accurately detect the temperature of the drive motor 2. For this reason, the temperature of the drive motor 2 becomes unknown in the device 1, and even if the temperature of the drive motor 2 rises, the rise cannot be suppressed. Therefore, in the drive control device 1 for an electric vehicle according to the present embodiment, the drive motor 2 may be damaged.

  Therefore, in the drive control device 1 for an electric vehicle according to the present embodiment, the electric power supplied to the drive motor 2 is reduced in order to eliminate the possibility of causing damage to the drive motor 2. That is, the target torque calculation unit 10 sets an upper limit value for the torque command value so as not to calculate a target torque equal to or higher than the upper limit value. Thereby, this apparatus 1 will restrict | limit the electric power added to the drive motor 2, and will suppress a temperature rise. For example, it is possible to prevent the drive motor 2 from being damaged during traveling to a repair shop.

  Thus, according to the present embodiment, the temperature of the drive motor 2 detected by the motor temperature detector 17, the value of the current flowing through the motor coil, and the correlation between the temperature and the resistance value of the motor coil are shown. A voltage value applied to the motor coil is estimated based on the map. That is, since the resistance value of the motor coil varies depending on the temperature, the resistance value of the motor coil is obtained from the temperature of the drive motor 2 detected by the motor temperature detection unit 17 and the correlation map, and this resistance value and the current flowing through the motor coil From this value, the voltage value is estimated.

  Further, the voltage applied to the motor coil is detected by the motor temperature detection unit 17, and this is compared with the estimated voltage value. Here, the estimated voltage value is close to the original value, that is, the voltage value detected by the motor voltage detection unit 16 unless the motor temperature detection unit 17 is malfunctioning. On the other hand, if the motor temperature detection unit 17 is out of order, the detected temperature becomes an abnormal value, and the resistance value of the motor coil also becomes an abnormal value, so the estimated voltage also becomes an abnormal value.

  For this reason, when the difference between the voltage values is equal to or greater than a predetermined value, it can be detected that the motor temperature detection unit 17 is malfunctioning. As described above, in the present embodiment, it is possible to determine the failure of the motor temperature detection unit 17 without having to perform an operation for increasing the motor temperature even though the motor temperature is high. Therefore, it is possible to detect a failure of the motor temperature detection unit 17 while preventing a motor failure.

  In addition to the map showing the correlation between the temperature of the drive motor 2, the value of the current flowing through the motor coil, and the temperature and the resistance value of the motor coil, the map is added to the drive motor 2 based on the rotational speed of the drive motor 2. The voltage value is estimated. Here, when the drive motor 2 is driven, an induced voltage is generated in the motor coil. Therefore, by estimating the voltage value based on the motor rotation speed, an accurate voltage value taking into account the induced voltage is estimated. Therefore, the voltage can be estimated with higher accuracy.

  Moreover, the motor temperature detection part 17 becomes a structure which cannot detect the temperature exceeding specific temperature at the time of failure. For this reason, when the detected temperature is larger than the specific temperature, it can be said that the motor temperature detection unit 17 has not failed. Therefore, when the temperature detected by the motor temperature detection unit 17 is equal to or lower than the specific temperature, it is possible to make an erroneous determination by determining whether or not the motor temperature detection unit 17 has failed. The sex can be reduced.

  Moreover, the motor temperature detection part 17 becomes a structure which cannot detect the temperature exceeding specific temperature at the time of failure. Here, generally, the resistance value of the motor coil tends to be small when the temperature is low. For this reason, when the motor temperature detection part 17 has failed, the voltage estimation part 18 will estimate a value smaller than an actual voltage value as a motor voltage. That is, when the motor temperature detection unit 17 is out of order, the estimated voltage value does not become larger than the actual voltage value. Therefore, it is possible to reduce erroneous determination by performing the failure determination only when the estimated voltage value is smaller than the actual voltage value.

  In addition, control is performed so that the target torque does not exceed a certain value when a failure of the motor temperature detector 17 is detected. For this reason, the temperature rise of the drive motor 2 is suppressed, and even if the motor temperature detector 17 fails and the temperature of the drive motor 2 cannot be accurately detected, the temperature remains until the drive motor 2 is damaged. It can be prevented from rising. Accordingly, it is possible to prevent the drive motor 2 from being damaged.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention. For example, in the above embodiment, the target torque calculation unit 10 calculates the target torque by inputting a signal indicating the accelerator opening and the vehicle speed. However, the present invention is not limited to this, and the target torque is calculated based on the shift position, the brake signal, and the like. The torque may be calculated.

  In the above embodiment, control is performed so that the target torque does not exceed a certain value when a failure of the motor temperature detection unit 17 is detected. However, the present invention is not limited to this, and for example, driving of the drive motor 2 is prohibited. You may do it. This also prevents the drive motor 2 from being damaged.

  In the above embodiment, the detected voltage value is compared with the estimated voltage value. However, the present invention is not limited to this, and the temperature of the drive motor 2 is detected, while the temperature of the drive motor 2 is estimated. The detected value and the estimated value may be compared to determine whether the motor temperature detecting unit 17 has failed. Specifically, as described above, the voltage estimation map unit 18a stores a map indicating the correlation between the temperature and the resistance value of the motor coil. For this reason, if the resistance value of the motor coil is found, the voltage estimation map unit 18a can estimate the temperature of the drive motor 2. Therefore, the voltage estimation map unit 18a reads a signal indicating the value of the current flowing through the motor coil, a signal indicating the rotation speed of the drive motor 2, and the voltage value detected by the motor temperature detection unit 17. Thus, the voltage estimation map unit 18a can estimate the temperature of the drive motor 2 from the stored map. The apparatus 1 detects a failure of the motor temperature detection unit 17 when the difference between the estimated temperature of the drive motor 2 and the temperature detected by the motor temperature detection unit 17 is equal to or higher than a certain temperature.

  Furthermore, when the configuration for estimating the temperature of the drive motor 2 is employed as described above, the apparatus 1 estimates the temperature of the drive motor 2 even if a failure occurs in the motor temperature detection unit 17. Information can be acquired. For this reason, this apparatus 1 may be comprised so that output torque control etc. may be performed based on the estimated temperature. However, in this case, since the temperature is an estimated value, when the drive motor 2 is driven based on the estimated value, the drive motor 2 may be damaged if the estimated value is incorrect. Therefore, when the vehicle is controlled by estimating the temperature of the drive motor 2, it is preferable to provide an upper limit for the torque command value as described above.

It is a block diagram of the drive control apparatus of the electric vehicle which concerns on embodiment. It is a block diagram which shows the detail of the electric current command value calculation part 11 shown in FIG. It is a block diagram which shows the detail of the voltage command value calculation part 13 shown in FIG. It is a block diagram which shows the detail of the motor temperature detection part 17 shown in FIG. It is a graph which shows the characteristic of the thermistor 17a shown in FIG. It is a graph which shows the voltage value in the connection point 17e shown in FIG. It is a block diagram which shows the detail of the voltage estimation part 18 shown in FIG. It is a flowchart which shows the failure judgment process by the drive control apparatus 1 of the electric vehicle which concerns on this embodiment. It is a flowchart which shows the failure judgment process by the drive control apparatus 1 of the electric vehicle which concerns on this embodiment, Comprising: The 2nd process example is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric vehicle drive control apparatus 2 ... Drive motor 10 ... Target torque calculation part (control means)
11: Current command value calculation unit (current command value calculation means)
12 ... Motor current detector (current detector)
13 ... Voltage command value calculation unit 14 ... Drive motor drive unit 15 ... Rotation speed detection section (rotation speed detection means)
16 ... Motor voltage detector (voltage detector)
17 ... Motor temperature detector (temperature detector)
17a ... Thermistor 17b ... Power supply unit 17c ... First resistor 17d ... Second resistor 17e ... Connection point 17f ... Converter 18 ... Voltage estimation unit (voltage estimation means)
18a ... Voltage estimation map unit 19 ... Failure detection unit (failure detection means)

Claims (8)

In a drive control device for an electric vehicle that determines a target torque and supplies AC power to a motor coil to drive the drive motor to generate the target torque.
Temperature detecting means for detecting the temperature of the drive motor;
Voltage detecting means for detecting a voltage applied to the motor coil;
A voltage for estimating the voltage applied to the motor coil based on the temperature of the drive motor detected by the temperature detection means, the value of the current flowing through the motor coil, and the correlation between the temperature and the resistance value of the motor coil. An estimation means;
A failure detection means for detecting that the temperature detection means is faulty when the difference between the voltage value estimated by the voltage estimation means and the voltage value detected by the voltage detection means is a predetermined value or more;
An electric vehicle drive control apparatus comprising: A rotation number detecting means for detecting the rotation number of the drive motor;
In addition to the temperature of the drive motor detected by the temperature detection means, the value of the current flowing through the motor coil, and the correlation between the temperature and the resistance value of the motor coil, the voltage estimation means is The drive control apparatus for an electric vehicle according to claim 1, wherein a voltage value applied to the drive motor is estimated based on the detected rotational speed of the drive motor. A current detecting means for detecting a value of a current flowing through the motor coil;
The drive control apparatus for an electric vehicle according to claim 1, wherein the voltage estimation unit uses a detection value of the current detection unit as a value of a current flowing through the motor coil. A current command value calculating means for obtaining a current value to be supplied to the motor coil so as to generate the target torque;
3. The voltage estimation unit uses a current value to be energized obtained by the current command value calculation unit as a value of a current flowing through the motor coil. Electric vehicle drive control device. The temperature detecting means has a configuration that cannot detect a temperature exceeding a specific temperature at the time of failure,
The failure determination means makes a failure determination as to whether or not the temperature detection means has failed when the temperature detected by the temperature detection means is equal to or lower than the specific temperature. The drive control apparatus of the electric vehicle of any one of Claim 4. The temperature detecting means has a configuration that cannot detect a temperature exceeding a specific temperature at the time of failure,
The failure detection means detects that the temperature detection means is faulty when the voltage value estimated by the voltage estimation means is smaller than a voltage value detected by the voltage detection means by a predetermined value or more. The drive control apparatus of the electric vehicle in any one of Claims 1-4 characterized by these. The temperature detecting means includes
A thermistor disposed adjacent to the drive motor and having a characteristic that the resistance value increases as the temperature decreases;
A power supply connected in series to the thermistor;
A resistor connected in parallel with the thermistor,
The voltage of the connection point between the thermistor, the power supply unit, and the resistor is detected, and the temperature of the drive motor is detected based on the correlation between the voltage value stored in advance and the temperature. The drive control apparatus of the electric vehicle in any one of Claim 5 or Claim 6. The control unit according to any one of claims 1 to 7, further comprising a control unit configured to control the target torque so that the target torque does not exceed a predetermined value when the failure detection unit detects a failure of the temperature detection unit. 2. A drive control device for an electric vehicle according to item 1.

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