Electric vehicle

Abstract

To provide a new technique for suppressing vibration generated in an electric vehicle being stopped.SOLUTION: An electric vehicle is provided with: a motor; a battery that supplies the motor with electric power; an inverter, provided between the battery and the motor, which converts DC power from the battery to AC power to be supplied to the motor; and a control device that controls operation of the inverter. The control device can execute specific operation involving distribution of power to the motor, while stopping the electric vehicle. The specific operation has a step of determining a target electric angle with respect to an electric angle of the motor, on the basis of an initial value of the electric angle; a step of controlling operation of the inverter, so that distribution of prescribed rated currents to the motor is started; and a step of identifying torque generated in the motor, on the basis of the rated currents and a current value of the electric angle, determining feedback torque for damping, on the basis of a deviation of the current value with respect to the target electric angle, and controlling currents distributed to the motor, on the basis of the generated torque, the feedback torque and the rated currents.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to electric vehicles. [Background technology]

[0002] Patent Document 1 discloses an electric vehicle including a motor that drives the wheels of the electric vehicle, a battery that supplies power to the motor, an inverter provided between the battery and the motor that converts DC power from the battery into AC power that is supplied to the motor, and a control device that controls the operation of the inverter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-182013 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an electric vehicle, electricity may be applied to the motor while the electric vehicle is stopped. When electricity is applied to the motor, torque is generated according to the electrical angle of the motor. Note that there are electrical angles at which no torque is generated even when electricity is applied to the motor. When torque is generated in the motor, the electrical angle of the motor fluctuates approximately around the electrical angle at which no torque is generated. In response to this, torque fluctuations occur in the motor, causing the electric vehicle to vibrate. In the electric vehicle of Patent Document 1, the electrical angle when the electric vehicle is stopped is adjusted to suppress vibrations in the electric vehicle while it is stopped.

[0005] This specification provides a novel technique for suppressing vibrations occurring in an electric vehicle when parked. [Means for solving the problem]

[0006] In a first aspect disclosed in the present specification, an electric vehicle includes a motor that drives wheels of the electric vehicle, a battery that supplies power to the motor, an inverter provided between the battery and the motor and that converts DC power from the battery into AC power that is supplied to the motor, and a control device that controls the operation of the inverter, wherein the control device is capable of executing a specific operation involving the supply of current to the motor while the electric vehicle is stopped, the specific operation may include a step of determining a target electrical angle for the electrical angle based on an initial value of the electrical angle of the motor, a step of controlling the operation of the inverter to start supplying current to the motor at a predetermined rated current, a step of determining a generated torque generated in the motor based on the rated current and a current value of the electrical angle, a feedback torque for vibration control based on a deviation of the current value from the target electrical angle, and a step of controlling the current supplied to the motor based on the generated torque, the feedback torque, and the rated current.

[0007] According to the above configuration, the control device controls the current supplied to the motor based on the generated torque, the feedback torque, and the rated current. In this case, the electrical angle of the motor can be brought closer to the target electrical angle. The target electrical angle is set to an electrical angle at which the generated torque is approximately zero when the motor is energized. This makes it possible to reduce the generated torque and suppress fluctuations in the generated torque. Therefore, it is possible to suppress vibrations occurring in the electric vehicle when it is stopped.

[0008] In a second aspect, in the first aspect described above, the control device, when controlling the current flow, may determine a target value of the current flow in accordance with a ratio obtained by dividing the sum of the generated torque and the feedback torque by the generated torque.

[0009] The generated torque is proportional to the current flowing through the motor. Therefore, the magnitude of the generated torque can be adjusted by adjusting the magnitude of the current flowing through the motor. By adjusting the magnitude of the generated torque, the electrical angle of the motor can be brought closer to the target electrical angle more quickly. Therefore, vibrations occurring in a parked electric vehicle can be suppressed more quickly.

[0010] In a third aspect, another electric vehicle includes a motor that drives wheels of the electric vehicle, a battery that supplies power to the motor, an inverter provided between the battery and the motor and that converts DC power from the battery into AC power that is supplied to the motor, and a control device that controls the operation of the inverter, wherein the control device is capable of executing a specific operation involving the supply of current to the motor while the electric vehicle is stopped, the specific operation including the steps of controlling the operation of the inverter to start supplying current to the motor at a predetermined rated current, determining a generated torque generated in the motor based on the rated current and a current value of the electrical angle of the motor, determining a feedback torque for vibration control based on the angular velocity of the electrical angle, and controlling the current supplied to the motor based on the generated torque, the feedback torque, and the rated current.

[0011] According to the above configuration, the control device controls the current supplied to the motor based on the generated torque, the feedback torque, and the rated current. In this case, the electrical angle of the motor can be brought close to the electrical angle at which the generated torque is substantially zero when the motor is energized. This makes it possible to reduce the generated torque and suppress fluctuations in the generated torque. Therefore, it is possible to suppress vibrations occurring in the electric vehicle when it is stopped.

[0012] In a fourth aspect, in the third aspect described above, when controlling the current flow, the control device determines a target value of the current flow in accordance with the ratio obtained by dividing the sum of the generated torque and the feedback torque by the generated torque.

[0013] The generated torque is proportional to the current flowing through the motor. Therefore, the magnitude of the generated torque can be adjusted by adjusting the magnitude of the current flowing through the motor. By adjusting the magnitude of the generated torque, the electrical angle of the motor can be brought closer to the target electrical angle more quickly. Therefore, vibrations occurring in a parked electric vehicle can be suppressed more quickly.

[0014] In a fifth aspect, in any one of the first to fourth aspects above, the specific operation may be a battery heating operation aimed at raising the temperature of the battery, or a neutral point charging operation in which an external power source is connected to a neutral point of the motor to charge the battery.

[0015] According to the above configuration, it is possible to suppress the occurrence of vibrations in the electric vehicle when the battery temperature increasing operation or the neutral point charging operation is being performed. [Brief description of the drawings]

[0016] [Figure 1] 2 shows a circuit diagram of the charging system 2. [Diagram 2] An example of a torque map 64 is shown. [Diagram 3] 4 shows a flowchart of a current supply control process according to the first embodiment. [Figure 4] 4 shows changes in electrical angle when a neutral point charging operation is performed in an electric vehicle according to a comparative example. [Diagram 5] 1 shows the transition of the electrical angle when a neutral point charging operation is performed in the electric vehicle 10 according to the first embodiment. [Figure 6] 13 shows a flowchart of a current supply control process according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] (First Example) 1, the charging system 2 includes an electric vehicle 10 and a charging device 100. The electric vehicle 10 includes a battery 12, a system main relay 14, a running smoothing capacitor 16, an inverter 20, a motor 30, a charging circuit 40, a charging inlet 50, and a control device 60. The charging inlet 50 is detachably connected to the charging device 100, and receives charging power for charging the battery 12.

[0018] The battery 12 is a rechargeable secondary battery, typically a lithium ion battery, that has multiple built-in secondary battery cells (not shown), such as lithium ion cells, and is configured to be repeatedly charged and discharged. The battery 12 is connected to the inverter 20 via a system main relay 14. The operation of the system main relay 14 is controlled by a control device 60. A smoothing capacitor 16 for running is provided between the battery 12 and the inverter 20.

[0019] The inverter 20 is provided between the running smoothing capacitor 16 and the motor 30. The inverter 20 is a device that converts DC power from the battery 12 into AC power. The inverter 20 includes three upper switching elements 22UH, 22VH, and 22WH, and three lower switching elements 22UL, 22VL, and 22WL. Hereinafter, the "switching elements" will be referred to as "SW elements." The upper SW elements 22UH, 22VH, and 22WH are connected in series with the lower SW elements 22UL, 22VL, and 22WL, respectively.

[0020] The midpoint between the upper SW element 22UH and the lower SW element 22UL connected in series is electrically connected to the U-phase terminal 32 of the motor 30. As a result, the upper SW element 22UH and the lower SW element 22UL form a pair of upper and lower U-phase arms that connect the U-phase terminal 32 of the motor 30 to the positive or negative electrode of the battery 12. Similarly, the upper SW element 22VH and the lower SW element 22VL connected in series form a pair of upper and lower V-phase arms, and the midpoint between them is electrically connected to the V-phase terminal 34 of the motor 30. The upper SW element 22WH and the lower SW element 22WL connected in series form a pair of upper and lower W-phase arms, and the midpoint between them is electrically connected to the W-phase terminal 36 of the motor 30. The operation of the three lower SW elements 22UL, 22VL, and 22WL and the operation of the three lower SW elements 22UL, 22VL, and 22WL are controlled by the control device 60.

[0021] The motor 30 is a three-phase AC motor that drives the front wheels of the electric vehicle 10 using power supplied from the battery 12. The motor 30 includes a U-phase coil 32A, a V-phase coil 34A, and a W-phase coil 36A. One ends of the U-phase coil 32A, the V-phase coil 34A, and the W-phase coil 36A are connected to a U-phase terminal 32, a V-phase terminal 34, and a W-phase terminal 36, respectively. The other ends of the U-phase coil 32A, the V-phase coil 34A, and the W-phase coil 36A are connected to each other at a neutral point 30A. The motor 30 further includes an electrical angle sensor 38 that detects the electrical angle of a rotor (not shown) of the motor 30.

[0022] The charging circuit 40 is a circuit for supplying power from the charging device 100 to the battery 12. The charging circuit 40 includes a first charging relay 42, a charging smoothing capacitor 44, and a second charging relay 46. The charging smoothing capacitor 44 is provided between the motor 30 and the charging inlet 50. The first charging relay 42 is provided between the neutral point 30A of the motor 30 and the first charging relay 42. The second charging relay 46 is provided between the charging inlet 50 and the charging smoothing capacitor 44. The operation of the first charging relay 42 and the second charging relay 46 is controlled by the control device 60.

[0023] The control device 60 is a computer equipped with a CPU. The control device 60 controls the operation of each component of the electric vehicle 10. The control device 60 includes a memory 62 that stores a torque map 64. As shown in FIG. 2, the torque map 64 is information indicating the relationship between the electrical angle [°] of the motor 30 and the generated torque [Nm]. The generated torque is torque generated in the motor 30 when current is applied to the motor 30. The torque map 64 is information used in the current control process (FIG. 3) described later. The magnitude of the generated torque is proportional to the current value applied to the motor 30. The torque map 64 is information corresponding to the rated current Ir of the motor 30 in the neutral point charging operation described later.

[0024] 1 is configured to be capable of executing a neutral point charging operation involving energization of the motor 30 while the electric vehicle 10 is stopped. The neutral point charging operation is an operation for boosting the voltage of the charging power received from the charging device 100 to charge the battery 12. The control device 60 executes the neutral point charging operation when the charging device 100 is connected to the charging inlet 50 and the voltage of the charging power received from the charging device 100 (e.g., 400 V) is lower than the rated voltage of the battery 12 (e.g., 800 V).

[0025] An outline of the neutral point charging operation will be described. As shown in FIG. 1, the control device 60 electrically connects the system main relay 14, the first charging relay 42, and the second charging relay 46. Then, the control device 60 performs a boost operation to charge the battery 12. Specifically, the control device 60 repeatedly turns on and off at least one of the lower SW elements 22UL, VL, and WL while maintaining the upper SW elements 22UH, 22VH, and 22WH in an off state. The control device 60 controls the duty ratio of the lower SW element to be turned on and off. The control device 60 may turn on and off the upper SW elements 22UH, 22VH, and 22WH symmetrically in synchronization with the lower SW elements 22UL, VL, and WL that are repeatedly turned on and off. For example, a case where the lower SW element 22UL is turned on and off will be described. When the lower SW element 22UL is on, a current flows through the U-phase coil 32A and the lower SW element 22UL. Energy is stored in the U-phase coil 32A. When the lower switching element 22UL is turned off in this state, the energy stored in the U-phase coil 32A is superimposed on the power from the charging device 100. As a result, the voltage of the power supplied from the inverter 20 to the battery 12 is boosted. This causes the battery 12 to be charged.

[0026] (Current control process; Fig. 3) The energizing current control process executed during the neutral point charging operation will be described with reference to Fig. 3. The energizing current control process is a process for controlling the energizing current I that is energized to the motor 30 during the neutral point charging operation. The control device 60 starts the process of Fig. 3 at the same time as the neutral point charging operation starts.

[0027] In S10, the control device 60 identifies the electrical angle of the motor 30 at the start of the neutral point charging operation (hereinafter, referred to as the “initial electrical angle φs”). The initial electrical angle φs is an initial value of the electrical angle of the motor 30.

[0028] In S12, the control device 60 determines a target electrical angle φt using the torque map 64 stored in the memory 62 and the initial electrical angle φs determined in S10. The control device 60 determines, as the target electrical angle φt, the electrical angle closest to the initial electrical angle φs among a plurality of electrical angles at which the generated torque is zero. For example, when the initial electrical angle φs is 110°, 120° is determined as the target electrical angle φt. Note that, in a modified example, the target electrical angle φt may be an electrical angle at which the generated torque when the motor 30 is energized is equal to or smaller than a predetermined torque.

[0029] In S14, the control device 60 controls the operation of the inverter 20 to start supplying current to the motor 30. The control device 60 determines the rated current Ir as a target value It of the current supply I, and controls the operation of the inverter 20 so that the target value It is reached.

[0030] In S20, the control device 60 identifies the current electrical angle φp of the motor 30.

[0031] In S22, the control device 60 determines whether or not a state in which the absolute value of the electrical angle difference, obtained by subtracting the current electrical angle φp from the target electrical angle φt, is less than a first predetermined value Va continues for a first predetermined time or more. The first predetermined value Va is a positive value. If the state in which the absolute value of the electrical angle difference is less than the first predetermined value Va continues for the first predetermined time or more (YES in S22), the control device 60 ends the process of FIG. 3. After ending the process of FIG. 3, the control device 60 continues the neutral point charging operation with the rated current Ir as the target value It. On the other hand, if the state in which the absolute value of the electrical angle difference is less than the first predetermined value Va has not continued for the first predetermined time or more (NO in S22), the control device 60 proceeds to S30.

[0032] In S30, the control device 60 determines the feedback torque Tf using the target electrical angle φt and the current electrical angle φp. Hereinafter, the feedback torque will be referred to as "FB torque." The FB torque Tf is a torque for suppressing vibrations occurring in the electric vehicle 10 while the vehicle is stopped. The control device 60 determines the FB torque Tf by multiplying a value obtained by subtracting the target electrical angle φt from the current electrical angle φp by a second predetermined value Vb. The second predetermined value Vb is a negative value.

[0033] In S32, the control device 60 determines the generated torque Tc using the rated current Ir, the torque map 64, and the current electrical angle φp.

[0034] In S34, the control device 60 calculates the output torque To. The control device 60 calculates the output torque To by adding the generated torque Tc to the FB torque Tf.

[0035] In S36, the control device 60 calculates a torque ratio R, which is a ratio obtained by dividing the output torque To by the generated torque Tc. That is, the torque ratio R is a ratio obtained by dividing the sum of the generated torque Tc and the FB torque Tf by the generated torque Tc.

[0036] In S40, the control device 60 determines whether the torque ratio R exceeds "1." If the torque ratio R exceeds "1" (YES in S40), the control device 60 proceeds to S42. On the other hand, if the torque ratio R is equal to or less than "1" (NO in S40), the control device 60 proceeds to S44.

[0037] In S42, the controller 60 determines the rated current Ir as the target value It. After completing S42, the controller 60 proceeds to S50.

[0038] Furthermore, in S44, the control device 60 determines whether the torque ratio R exceeds "0 (zero)". If the torque ratio R exceeds "0" (YES in S44), the control device 60 proceeds to S46. On the other hand, if the torque ratio R is equal to or less than "0" (NO in S44), the control device 60 proceeds to S48.

[0039] In S46, the control device 60 determines the target value It to be the value (R*Ir) obtained by multiplying the rated current Ir by the torque ratio R. In this case, the target value It is a value equal to or less than the rated current Ir. After completing S46, the control device 60 proceeds to S50.

[0040] In S48, the control device 60 determines the current value "0 (zero)" as the target value It. When S48 ends, the control device 60 proceeds to S50.

[0041] In S50, the control device 60 controls the energizing current I so that it becomes the determined target value It. When S50 ends, the control device 60 returns to S20.

[0042] As described above, the control device 60 executes the processes of S30 to S50 until a YES determination is made in S22.

[0043] The effect of the energizing current control process (see FIG. 3) will be described with reference to FIG. 4 and FIG. 5. The vertical axis of the time charts in FIG. 4 and FIG. 5 indicates the electrical angle of motor 30. In the initial state in FIG. 4 and FIG. 5, the electrical angle of motor 30 of electric vehicle 10 at a stop is 117°. FIG. 4 shows the transition of the electrical angle in an electric vehicle of a comparative example, and FIG. 5 shows the transition of the electrical angle in electric vehicle 10 of this embodiment. The electric vehicle of the comparative example has a similar configuration to electric vehicle 10, except that it does not execute the energizing current control process (see FIG. 3).

[0044] In FIG. 4, when the neutral point charging operation is started, the electric vehicle of the comparative example starts to supply current to the motor. As shown in FIG. 2, the generated torque Tc is a positive value when the electrical angle of the motor is 117°. Therefore, as shown in FIG. 4, when the supply of current to the motor is started, a positive generated torque Tc is generated in the motor, and the electrical angle of the motor becomes large. Then, (1) when the electrical angle of the motor exceeds 120°, a negative generated torque Tc is generated in the motor. Therefore, the electrical angle of the motor becomes small. Then, (2) when the electrical angle of the motor becomes smaller than 120°, a positive generated torque Tc is generated in the motor, and the electrical angle of the motor becomes large. After that, (1) and (2) are repeated. That is, the electrical angle of the motor fluctuates approximately around 120°. In response to this, torque fluctuation occurs in the motor, and the electric vehicle of the comparative example vibrates. Note that the torque fluctuation of the motor may also cause teeth rattle noise in the drive system of the electric vehicle of the comparative example.

[0045] In FIG. 5, when the neutral point charging operation is started, the electric vehicle 10 specifies the initial electrical angle φs (117°) (S10 in FIG. 3), determines 120° as the target electrical angle φt (S12), and starts energizing the motor 30 (S14). As in the comparative example in FIG. 4, when energizing the motor 30 is started, a positive generated torque Tc is generated in the motor 30, and the electrical angle of the motor 30 increases. In the energizing current control process (see FIG. 3), when the current electrical angle φp of the motor 30 is 120° or less, the FB torque Tf has a positive value (S30). Therefore, the torque ratio R becomes greater than 1 (YES in S40), and the target value It becomes the rated current Ir (S42). Also, when the current electrical angle φp is greater than 120°, the FB torque Tf becomes a negative value (S22). Therefore, the torque ratio R becomes smaller than 1 (NO in S40, YES in S44). In this case, the torque ratio R is greater than zero. Therefore, the target value It becomes "R*Ir" (S46). As a result, in a situation where the current electrical angle φp is greater than 120°, the target value It becomes smaller than the rated current Ir, and the absolute value of the generated torque Tc of the motor 30 becomes smaller than the absolute value of the generated torque Tc when the target value It is the rated current Ir. As the absolute value of the generated torque Tc becomes smaller, the amplitude of the electrical angle becomes smaller compared to when the target value It is the rated current Ir. As the amplitude of the electrical angle becomes smaller, the absolute value of the generated torque Tc when the electrical angle is 120° or less also becomes smaller. As the amplitude of the electrical angle becomes smaller in this way, the fluctuation of the electrical angle of the motor 30 is suppressed, and the electrical angle approaches the target electrical angle φt. As a result, the vibration of the electric vehicle 10 is suppressed. In addition, the gear rattle noise of the drive system of the electric vehicle 10 is also suppressed.

[0046] As described above, the electric vehicle 10 includes the motor 30 that drives the front wheels (an example of a "wheel") of the electric vehicle 10, the battery 12 that supplies power to the motor 30, the inverter 20 that is provided between the battery 12 and the motor 30 and converts DC power from the battery 12 into AC power that is supplied to the motor 30, and the control device 60 that controls the operation of the inverter 20. The control device 60 is capable of executing a neutral point charging operation (an example of a "specific operation") that involves energizing the motor 30 while the electric vehicle 10 is stopped. The neutral point charging operation includes a step (S12 in FIG. 2) of determining a target electrical angle φt based on an initial electrical angle φs (an example of an "initial value of the motor electrical angle"), a step (S14) of controlling the operation of the inverter 20 to start supplying current to the motor 30 at a predetermined rated current Ir, a step (S32) of specifying a generated torque Tc generated in the motor 30 based on the rated current Ir and a current electrical angle φp (an example of a "current value of the electrical angle"), a step (S30) of determining a FB torque Tf based on the deviation of the current electrical angle φp from the target electrical angle φt, and a step (S30-S50) of controlling the current I supplied to the motor 30 based on the generated torque Tc, the FB torque Tf, and the rated current Ir.

[0047] According to the above configuration, the control device 60 controls the energization current I to the motor 30 based on the generated torque Tc, the FB torque Tf, and the rated current Ir. In this case, the electrical angle of the motor 30 can be brought closer to the target electrical angle φt. This makes it possible to reduce the generated torque Tc and suppress fluctuations in the generated torque Tc. Therefore, it is possible to suppress vibrations occurring in the parked electric vehicle 10 during the execution of the neutral point charging operation.

[0048] In addition, when controlling the energizing current I, the control device 60 determines a target value It of the energizing current I according to a torque ratio R, which is a ratio obtained by dividing the sum of the generated torque Tc and the FB torque Tf by the generated torque Tc (S40 to S48).

[0049] The generated torque Tc is proportional to the current flow I. Therefore, the magnitude of the generated torque Tc can be adjusted by adjusting the magnitude of the current flow I. By adjusting the magnitude of the generated torque Tc, the electrical angle of the motor 30 can be made to approach the target electrical angle φt more quickly. Therefore, vibrations occurring in the electric vehicle 10 during a stop can be suppressed more quickly.

[0050] (Second Example) The electric vehicle 10 of the second embodiment differs in that it executes the energizing current control process of FIG. 6 instead of the energizing current control process of FIG.

[0051] (Current control process; Fig. 6) The energizing current control process executed during the neutral point charging operation will be described with reference to Fig. 6. S114 is the same as S14 in Fig. 3.

[0052] In S120, the control device 60 determines the angular velocity ω of the motor 30.

[0053] In S122, the control device 60 judges whether the state in which the absolute value of the angular velocity ω is less than the third predetermined value Vc continues for a second predetermined time or more. The third predetermined value Vc is a positive value. If the state in which the absolute value of the angular velocity ω is less than the third predetermined value Vc continues for a second predetermined time or more (YES in S122), the control device 60 ends the process of FIG. 6. After ending the process of FIG. 6, the control device 60 continues the neutral point charging operation with the rated current Ir as the target value It of the current I. On the other hand, if the state in which the absolute value of the angular velocity ω is less than the third predetermined value Vc has not continued for a second predetermined time or more (NO in S122), the control device 60 proceeds to S130.

[0054] In S130, the control device 60 determines the FB torque Tf by using the angular velocity ω. The control device 60 determines the FB torque Tf by multiplying the angular velocity ω by a fourth predetermined value Vd. The fourth predetermined value Vd is a negative value.

[0055] S132 to S150 are the same as S32 to S50 in FIG.

[0056] In this embodiment, the FB torque Tf is determined using the angular velocity ω, so that the vibration of the electric vehicle 10 during the neutral point charging operation can be suppressed.

[0057] As described above, the electric vehicle 10 includes the motor 30 that drives the front wheels of the electric vehicle 10, the battery 12 that supplies power to the motor 30, the inverter 20 that is provided between the battery 12 and the motor 30 and converts DC power from the battery 12 into AC power that is supplied to the motor 30, and the control device 60 that controls the operation of the inverter 20. The control device 60 is capable of performing a neutral point charging operation involving energization of the motor 30 while the electric vehicle 10 is stopped. The neutral point charging operation includes a step (S114) of controlling the operation of the inverter 20 to start energizing the motor 30 at a predetermined rated current Ir, a step (S132) of specifying a generated torque Tc generated in the motor 30 based on the rated current Ir and the current angular velocity ω of the motor 30, a step (S130) of determining a FB torque Tf for vibration suppression based on the current angular velocity ω, and a step (S140 to S150) of controlling the energization current I to the motor 30 based on the generated torque Tc, the FB torque Tf, and the rated current Ir.

[0058] According to the above configuration, the control device 60 controls the current I supplied to the motor 30 based on the generated torque Tc, the FB torque Tf, and the rated current Ir. In this case, the electrical angle of the motor 30 can be brought close to an electrical angle at which the generated torque is substantially zero when the motor 30 is energized. This makes it possible to reduce the generated torque Tc and suppress fluctuations in the generated torque Tc. Therefore, it is possible to suppress vibrations occurring in the electric vehicle 10 when the vehicle is stopped.

[0059] In addition, when controlling the energizing current I, the control device 60 determines a target value It of the energizing current I according to a torque ratio R which is a ratio obtained by dividing the sum of the generated torque Tc and the FB torque Tf by the generated torque Tc.

[0060] The generated torque Tc is proportional to the current flow I. Therefore, the magnitude of the generated torque Tc can be adjusted by adjusting the magnitude of the current flow I. By adjusting the magnitude of the generated torque Tc, the electrical angle of the motor 30 can be made to approach the target electrical angle φt more quickly. Therefore, vibrations occurring in the electric vehicle 10 during a stop can be suppressed more quickly.

[0061] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Modifications of the above embodiments are listed below.

[0062] The control device 60 may be capable of executing a battery heating operation for raising the temperature of the battery 12 while the electric vehicle 10 is stopped. For example, in the battery heating operation, the control device 60 controls the operation of the inverter 20 and the motor 30 to overheat the coolant in the drive system of the electric vehicle 10. Then, the heated coolant is used to raise the temperature of the battery 12. In this modification, the control device 60 executes the current control process of FIG. 3 or FIG. 6 in the battery heating operation. With this configuration, it is possible to suppress vibration of the electric vehicle 10 during the battery heating operation.

[0063] The technical elements described in this specification or drawings have technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0064] 2: charging system, 10: electric vehicle, 12: battery, 14: system main relay, 16: running smoothing capacitor, 20: inverter, 22UH: upper switch element, 22UL: lower switch element, 22VH: upper switch element, 22VL: lower switch element, 22WH: upper switch element, 22WL: lower switch element, 30: motor, 30A: neutral point, 32: U-phase terminal, 32A: U-phase coil, 34: V-phase terminal, 34A: V-phase coil, 36: W-phase terminal, 36A: W-phase coil, 38: electrical angle sensor, 40: charging circuit, 42: first charging relay, 44: charging smoothing capacitor, 46: second charging relay, 50: charging inlet, 60: control device, 62: memory, 64: torque map

Claims

1. An electric vehicle, A motor that drives wheels of the electric vehicle; a battery for supplying power to the motor; an inverter provided between the battery and the motor, the inverter converting DC power from the battery into AC power to be supplied to the motor; A control device for controlling an operation of the inverter, the control device is capable of executing a specific operation involving energization of the motor in a state in which the electric vehicle is stopped, The specific operation is: determining a target electrical angle for the electrical angle of the motor based on an initial value of the electrical angle of the motor; controlling an operation of the inverter to start supplying a predetermined rated current to the motor; determining a torque generated in the motor based on the rated current and the current value of the electrical angle; determining a feedback torque for vibration suppression based on a deviation of the current value from the target electrical angle; controlling a current supplied to the motor based on the generated torque, the feedback torque, and the rated current; Electric car.

2. 2. The electric vehicle according to claim 1, wherein, when controlling the energizing current, the control device determines a target value of the energizing current in accordance with a ratio obtained by dividing a sum of the generated torque and the feedback torque by the generated torque.

3. An electric vehicle, A motor that drives wheels of the electric vehicle; a battery for supplying power to the motor; an inverter provided between the battery and the motor, the inverter converting DC power from the battery into AC power to be supplied to the motor; A control device for controlling the operation of the inverter, the control device is capable of executing a specific operation involving energization of the motor in a state in which the electric vehicle is stopped, The specific operation is: controlling an operation of the inverter to start supplying a predetermined rated current to the motor; determining a torque generated in the motor based on the rated current and a current value of an electrical angle of the motor; determining a feedback torque for vibration suppression based on an angular velocity of the electrical angle; controlling a current supplied to the motor based on the generated torque, the feedback torque, and the rated current; Electric car.

4. 4. The electric vehicle according to claim 3, wherein, when controlling the energizing current, the control device determines a target value of the energizing current in accordance with a ratio obtained by dividing a sum of the generated torque and the feedback torque by the generated torque.

5. 5. The electric vehicle according to claim 1, wherein the specific operation is a battery heating operation for heating the battery, or a neutral point charging operation for connecting an external power source to a neutral point of the motor to charge the battery.

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