Electric vehicle control method and electric vehicle control device

Abstract

To realize a desired acceleration / deceleration state in an electric vehicle that adopts an induction motor as a motor for driving.SOLUTION: An electric vehicle control method includes: a first torque target value calculation process of calculating a first torque target value on the basis of vehicle information; a disturbance torque estimating process of estimating disturbance torque Td working on a motor 101; a second torque target value calculation process of calculating a second torque target value Tm2* from the first torque target value Tm1* and the disturbance torque Td; and an excitation current command value calculation process of calculating an excitation current command value iγ* on the basis of the second torque target value Tm2*. Especially in the disturbance torque estimating process, an actual excitation current response SUB> / SUB>^ as a response of actual rotor magnetic flux to the excitation current command value iγ* is defined, a corrected second torque target value Tm2_pr* is obtained on the basis of the actual excitation current response SUB> / SUB>^, and the disturbance torque Td is calculated on the basis of the corrected second torque target value Tm2_pr*.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an electric vehicle control method and an electric vehicle control device. [Background technology]

[0002] Patent Document 1 describes an electric vehicle control method that estimates disturbance torque (torque generated by the influence of gradients, etc.) acting on a drive motor and controls the torque of the drive motor based on the estimated disturbance torque. In particular, Patent Document 1 calculates a basic torque target value (torque table target value) that is determined based on the required driving force for the electric vehicle (such as the amount of accelerator pedal operation by the occupant) and the vehicle speed, and then calculates a corrected torque target value (first torque target value) by correcting the basic torque target value based on the estimated disturbance torque. Then, by controlling the power supplied to the drive motor based on this corrected torque target value, a desired acceleration / deceleration state is achieved in the electric vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6135775 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, the present inventors have noticed that in a motor control system that employs a so-called induction motor as a drive motor, if the control of Patent Document 1 is applied as is, sufficient accuracy in estimating disturbances cannot be ensured. Specifically, in an induction motor control system, variations in motor torque response occur depending on the motor operating point (particularly the control state of the excitation current), which causes errors in the estimation calculation of disturbance torque. As a result, errors also occur in the calculation of the correction torque target value determined from this disturbance torque, resulting in the problem that the desired acceleration / deceleration state of the electric vehicle cannot be achieved.

[0005] Therefore, an object of the present invention is to provide an electric vehicle control method and an electric vehicle control device that can achieve desired acceleration and deceleration states in an electric vehicle that employs an induction motor as a drive motor. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided an electric vehicle control method for controlling an electric vehicle equipped with a drive motor constituted by an induction motor as a driving source for traveling, the electric vehicle control method including a first torque target value calculation step of calculating a first torque target value based on vehicle information, a disturbance torque estimation step of estimating a disturbance torque acting on the motor, a second torque target value calculation step of calculating a second torque target value from the first torque target value and the disturbance torque, and an excitation current command value calculation step of calculating an excitation current command value based on the second torque target value.

[0007] Then, in the disturbance torque estimation process, an actual rotor flux response is defined as the response of the actual rotor flux to the excitation current command value, a corrected second torque target value, which is a correction value of the second torque target value, is obtained based on the actual rotor flux response, and the disturbance torque is calculated based on the corrected second torque target value. [Effects of the Invention]

[0008] According to the present invention, it is possible to achieve desired acceleration and deceleration states in an electric vehicle that employs an induction motor as a drive motor. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram illustrating the system configuration of an electric vehicle in which an electric vehicle control method according to an embodiment of the present invention is executed. [Figure 2] FIG. 2 is a diagram showing an example of an accelerator opening-torque table. [Figure 3] FIG. 3 is a diagram showing a model of a driving force transmission system of an electric vehicle. [Figure 4] FIG. 4 is a block diagram showing the configuration of the second torque target value calculation unit. [Figure 5] FIG. 5 is a block diagram showing the configuration of the disturbance torque estimating unit. [Figure 6] FIG. 6 is a block diagram showing the configuration of the response delay processing unit. [Figure 7] FIG. 7 is a timing chart showing the first control results of the example and the comparative example. [Figure 8] FIG. 8 is a timing chart showing the second control results of the example and the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an electric vehicle control method according to each embodiment of the present invention will be described with reference to the drawings.

[0011] [First embodiment] 1 is a block diagram illustrating the system configuration of an electric vehicle 10 in which an electric vehicle control method is executed. The concept of the electric vehicle 10 in this embodiment includes an electric vehicle (EV) or a hybrid electric vehicle (HEV) equipped with at least one electric motor as a driving source.

[0012] As shown in the figure, the system of the electric vehicle 10 mainly includes a drive motor 101, an inverter 102, a battery 106, and a drive force transmission system (a reduction gear 103, a drive shaft 104, and drive wheels 105).

[0013] The drive motor 101 is configured by an induction motor (IM). In particular, the drive motor 101 generates drive force using AC current supplied from an inverter 102, and transmits the drive force to each drive wheel 105 via a reducer 103 and a drive shaft 104. The drive motor 101 also recovers, as electric energy, kinetic energy based on regenerative braking force received from each drive wheel 105 while the vehicle is running.

[0014] The inverter 102 is composed of two pairs of switching elements (power semiconductor elements such as IGBTs and MOS-FETs) for each phase for stator current control. By turning the switching elements on and off in response to a drive signal, it converts the direct current supplied from the battery 106 into alternating current and supplies the desired current to the traction motor 101. The inverter 102 also connects two pairs of switching elements (power semiconductor elements such as IGBTs and MOS-FETs) to each end of the rotor winding for rotor current control (four in total). By turning the switching elements on and off in response to a drive signal, it supplies the desired current from the battery 106 to the rotor winding of the traction motor 101. If the current flowing through the rotor winding is unidirectional, the two diagonally positioned switching elements of the two pairs of switching elements may be replaced with diodes. During regenerative operation of the traction motor 101, the inverter 102 converts the alternating current generated by the traction motor 101 into direct current and supplies it to the battery 106.

[0015] The battery 106 is configured by an on-board secondary battery (such as a stacked lithium ion battery) that can supply (discharge) drive power when the drive motor 101 is in power running mode and can receive (charge) regenerated power when the drive motor 101 is in regenerative running mode.

[0016] The motor controller 107 controls the vehicle speed V, the accelerator opening APO, the rotor phase α of the drive motor 101, and the stator current (three-phase AC current i u ,i v ,i w ) and other vehicle variables as digital signals, and generates a PWM signal based on the digital signal. The motor controller 107 also generates a drive signal (D uu * ,D ul * ,D vu * ,D vl * ,D wu * ,D wl * ,D fu* ,D fl * The detailed configuration of the motor controller 107 will be described later.

[0017] The system of the electric vehicle 10 is also provided with a current sensor 108 and a magnetic position detector 112. The current sensor 108 detects the current (three-phase AC current i u ,i v ,i w ) and outputs it to the motor controller 107. u ,i v ,i w Since the sum of these is 0, the currents of any two phases may be detected and the current of the remaining phase may be found by calculation. The magnetic position detector 112 is, for example, a resolver or an encoder, and detects the rotor position (rotor phase α) of the drive motor 101 and outputs A-phase, B-phase, and Z-phase pulses corresponding to the rotor position to the motor controller 107.

[0018] The following describes in detail the configuration of the motor controller 107. The motor controller 107 has an AD converter 109, a conversion angle calculator 110, a three-phase to two-phase current converter 111, a pulse counter 113, an angular velocity calculator 114, a first torque target value calculator S115, a second torque target value calculator S116, a current command value calculator 117, an excitation current controller 118, a torque current controller 119, a slip angle frequency controller 120, a decoupling controller 121, a voltage command value calculator 122, and a two-phase to three-phase current converter 123.

[0019] The AD converter 109 obtains a current value by sampling the three-phase AC current detection value acquired from the current sensor 108 , and outputs the current value to the three-phase to two-phase current converter 111 .

[0020] The conversion angle calculator 110 receives a power supply angular velocity ω, which will be described later, as an input, and integrates the power supply angular velocity ω to calculate a power supply angle θ.

[0021] The three-phase to two-phase current converter 111 converts the three-phase AC current i detected by the current sensor 108 into u ,i v ,i w γ-axis current (excitation current) i γ , δ-axis current (torque current) i δ Convert to.

[0022]

number

[0023] It should be noted that the current sensor 108 detects two-phase current (for example, u-phase current i u ,v phase current i v ), the current of the remaining phase (for example, the w-phase current i w ) into equation (1) to obtain the γδ-axis current i γ ,i δ Calculate the following.

[0024]

number

[0025] In this embodiment, the γ-axis current i γ and δ-axis current i δ correspond to the measured (detected) excitation current (measured value of the excitation current) and the measured (detected) torque current (measured value of the torque current), respectively.

[0026] The pulse counter 113 calculates the rotor mechanical angle θ of the drive motor 101 from the A-phase, B-phase, and Z-phase pulses input from the magnetic position detector 112. rm The angular velocity calculator 114 calculates the rotor mechanical angle θ rm is input, and the rotor mechanical angle θ rm The rotor mechanical angular velocity ω is the time rate of change of rm The angular velocity calculator 114 calculates the rotor mechanical angular velocity ω rm The rotor electrical angular velocity ω is calculated by multiplying it by the number of motor pole pairs p.re Calculate the following.

[0027] The first torque target value calculation unit S115 receives the vehicle speed V and the accelerator opening APO as inputs, refers to the accelerator opening-torque table shown in FIG. 2, and calculates the first torque target value T m1 * That is, the first torque target value T m1 * is calculated as a torque value corresponding to the required output for the drive motor 101 (required driving force for the electric vehicle 10).

[0028] The vehicle speed V can be acquired by communication from a controller other than the motor controller 107 mounted on the electric vehicle 10, such as a meter or a brake controller. rm may be multiplied by the tire dynamic radius r, and the obtained value is divided by the gear ratio of the final gear to obtain the vehicle speed v (m / s), which is then multiplied by 3600 / 1000 to convert the unit to calculate the vehicle speed V (km / h).Furthermore, the accelerator opening APO (%) is obtained from an accelerator opening sensor (not shown) or obtained via communication from another controller (not shown) such as a vehicle controller.

[0029] The second torque target value calculation unit S116 calculates the rotor mechanical angular speed ω rm and the first torque target value T m1 * is used as input, and the second torque target value T m2 * The second torque target value T m2 * is a torque target value T m1 * is the torque corrected for

[0030] Specifically, the second torque target value calculation unit S116 calculates a disturbance torque T dThen, the second torque target value calculation section S116 calculates the first torque target value T m1 * is the estimated disturbance torque T d_e The second torque target value T m2 * The details of the processing in the second torque target value calculation section S116 will be described later.

[0031] The current command value calculation unit 117 calculates the second torque target value T m2 * , rotor mechanical angular velocity ω rm (motor rotation speed), and DC voltage V dc is input, and the γ-axis current command value (excitation current command value) i is calculated by referring to the map data stored in memory in advance. γ * and δ-axis current command value (torque current command value) i δ * The DC voltage V dc (V) can be determined based on a detected value of a voltage sensor (not shown) provided on the connection line of the battery 106, or an estimated value of the power supply voltage estimated by a battery controller (not shown).

[0032] The excitation current control unit 118 calculates the γ-axis current command value i γ * is input, and the first γ-axis voltage command value v γ1 * More specifically, the excitation current control unit 118 calculates the γ-axis current command value i γ * The γ-axis current i calculated based on equation (1) is γ The first γ-axis voltage command value v γ1 * Calculate.

[0033] The torque current control unit 119 calculates the δ-axis current command value i δ * is input, and the first δ-axis voltage command value v δ1 * More specifically, the torque current control unit 119 calculates the δ-axis current command value i δ* The δ-axis current i calculated based on equation (1) is δ The first δ-axis voltage command value v δ1 * Calculate.

[0034] The slip angle frequency control unit 120 calculates the rotor electrical angular velocity ω re and the γ-axis current i calculated based on equation (1) γ and δ-axis current i δ More specifically, the slip angle frequency control unit 120 first calculates the power supply angular velocity ω based on the following equation (3): γ and δ-axis current i δ slip angular velocity ω se Ask for.

[0035]

number

[0036] In addition, "M" and "R" in formula (3) r " and "L r " is a parameter determined according to the characteristics of the drive motor 101. More specifically, "M" is the mutual inductance, and "R r " is the rotor resistance, and "L r " indicates the rotor self-inductance. γ " indicates the rotor magnetic flux and is determined based on the following equation (4).

[0037]

number

[0038] In addition, "τ φ " indicates the rotor flux response time constant.

[0039] The slip angle frequency control unit 120 calculates the rotor electrical angular velocity ω re The slip angular velocity ω calculated based on the above formulas (3) and (4) seThe power supply angular velocity ω is calculated by adding

[0040] The decoupling control unit 121 calculates the power supply angular velocity ω and the γ-axis current i γ and δ-axis current i δ and, as input, the non-interfering voltage v γ_dcpl ,v δ_dcpl Calculate the non-interfering voltage v γ_dcpl ,v δ_dcpl is a correction voltage for canceling out the interference voltage between the γ-δ orthogonal coordinate axes. More specifically, the decoupling control unit 121 calculates the decoupling voltage v based on the following equation (5): γ_dcpl ,v δ_dcpl Calculate.

[0041]

number

[0042] In addition, "L s " denotes the stator self-inductance of the drive motor 101. Also, "σ" denotes the leakage coefficient.

[0043] The voltage command value calculation unit 122 calculates the first γ-axis voltage command value v γ1 * and the first δ-axis voltage command value v δ1 * and the γ-axis non-interacting voltage v γ_dcpl and δ-axis non-interacting voltage v δ_dcpl By adding γ2 * and the second δ-axis voltage command value v δ2 * Then, the voltage command value calculation unit 122 calculates the calculated second γ-axis voltage command value v γ2 * and the second δ-axis voltage command value v δ2 * The final γ-axis voltage command value v γ * and δ-axis voltage command value v δ *Note that, by employing the γδ-axis decoupling voltage correction by the decoupling control unit 121, the calculation of each voltage command value can be realized by a PI feedback compensator based on a simple one-input one-output control logic.

[0044] The two-phase / three-phase current converter 123 calculates the γδ-axis current command value v using the power supply angle θ. γ * ,v δ * The three-phase voltage command value v is calculated by performing coordinate transformation based on the following equation (6). u * ,v v * ,v w * Ask for.

[0045]

number

[0046] Next, the details of the processing in the second torque target value calculation section S116 will be described. In particular, in the second torque target value calculation section S116 of this embodiment, the motor torque T m from the rotor mechanical angular velocity ω rm Transfer characteristics G p (s) and the transfer characteristic G p (s) to estimate the disturbance torque T d_e Therefore, first, the transfer characteristic G p (s) will be explained.

[0047] <Transfer characteristics G p (s)> 3 is a diagram showing a model of the driving force transmission system of the electric vehicle 10. The definitions of each parameter, including those already explained, are shown below.

[0048] J m : Motor inertia J w : Inertia of the drive wheels M: Vehicle weight K D : Torsional rigidity of the drivetrain K T : Coefficient of friction between the tire and road surface N: Overall gear ratio r: tire load radius ω rm : Motor mechanical angular velocity T m :Motor torque T D : Torque of the drive wheels F: Force applied to the vehicle V:Vehicle speed ω w : Angular velocity of the drive wheels

[0049] From FIG. 3, the equations of motion of the electric vehicle 10 are expressed by the following equations (7) to (11).

[0050]

number

[0051] Based on the above equations of motion (7) to (11), the transfer characteristic G p (s) is expressed as the following equations (12) to (20).

[0052]

number

[0053] Note that "s" in equation (12) represents the Laplace operator. Furthermore, by transforming equation (12), the following equation (21) is obtained.

[0054]

number

[0055] The coefficients a'1 to a'3 and b'0 to b'2 in equation (21) are values ​​determined by the coefficients a1 to a4 and b0 to b3 defined in equations (13) to (20).

[0056] Here, the transfer characteristic Gp When examining the poles and zeros of (s), they show extremely high values. In other words, this means that α and β in equation (21) show values ​​that are very close to each other. Therefore, by performing pole-zero cancellation (approximation processing with α = β) on equation (21), the transfer characteristic G p (s) can be expressed as a rational function with a quadratic numerator and a cubic denominator as shown in the following equation (22).

[0057]

number

[0058] Here, if we rewrite equation (22), the transfer characteristic G p (s) can be expressed as the following equation (23).

[0059]

number

[0060] However, "M" in equation (23) p " is a constant that does not depend on the Laplace operator s. Also, "ζ z "," "ζ p ", "ω z " and "ω p " is determined by the following equations (24) to (27).

[0061]

number

[0062] <Second torque target value calculation process> 4 is a block diagram showing the configuration of the second torque target value calculation unit S116. As shown in the figure, the second torque target value calculation unit S116 has a disturbance torque estimation unit S401, a gain processing unit S402, and an addition unit S403.

[0063] The disturbance torque estimation unit S401 estimates the rotor mechanical angular velocity ω rm and the second torque target value T m2* is used as input, and the disturbance torque estimate T d_e Calculate the following.

[0064] 5 is a block diagram showing the configuration of the disturbance torque estimation unit S401. As shown in the figure, the disturbance torque estimation unit S401 has a first filter processing unit S501, a response delay processing unit S502, a second filter processing unit S503, and an adder S504. In this embodiment, the first filter processing unit S501 functions as a first torque estimation value calculation unit, and the response delay processing unit S502 and the second filter processing unit S503 function as a second torque estimation value calculation unit.

[0065] The first filter processing unit S501 calculates the rotor mechanical angular velocity ω that indicates the vehicle speed V of the electric vehicle 10. rm A predetermined first filter is applied to the first torque estimate T m1 ^ In particular, the first filter calculates the motor torque T m from the rotor mechanical angular velocity ω rm Transfer characteristics G p H(s) / G where (s) is the denominator and the low-pass filter H(s) is the numerator p (s). The order of the low-pass filter H(s) is the first filter H(s) / G p The order of the denominator of (s) is determined to be equal to or greater than the order of the numerator. m1 ^ is the first torque target value T m1 * The actual motor torque T m (actual torque response).

[0066] The response delay processing unit S502 calculates the second torque target value T m2 * (In particular, the second torque target value T m2 * The previous value of is used as input, and the response delay processing value T m2_pr * Ask for.

[0067] 6 is a block diagram showing the configuration of the response delay processing unit S502. As shown in the figure, the response delay processing unit S502 has a current command value calculation unit S601, a response model unit S602, and a response delay processing value calculation unit S603.

[0068] The current command value calculation unit S601 calculates the second torque target value T m2 * , rotor mechanical angular velocity ω rm , and DC voltage V dc is input, and the δ-axis current command value i δ * and γ-axis current command value i γ * Calculate the following.

[0069] The response model unit S602 calculates the δ-axis current command value i δ * and γ-axis current command value i γ * are input and subjected to low-pass filtering to obtain the δ-axis current estimate i δ ^ and the estimated γ-axis current value i γ ^ The estimated δ-axis current value i δ ^ and the estimated γ-axis current value i γ ^ is the δ-axis current i that is actually output for each command value. δ (actual torque current response) and γ-axis current i γ (actual excitation current response). The response model unit S602 calculates the estimated γ-axis current value i γ ^ Further low-pass filtering is performed on the rotor flux estimate φ γ ^ The rotor flux estimate value φ γ ^ is the estimated γ-axis current value i γ ^ The rotor magnetic flux φ that is actually output according to (actual excitation current response) γ (actual rotor flux response).

[0070] Here, the motor torque T in the induction motor m is given by the following equation (28).

[0071]

number

[0072] In addition, "K T " is a parameter determined according to the characteristics of the driving motor 101. That is, the motor torque T m is the δ-axis current i δ and rotor flux φ γ It is determined by the product of

[0073] On the other hand, the rotor flux φ γ is the γ-axis current i γ Therefore, the δ-axis current i δ and rotor flux φ γ As a result, a large difference in response speed occurs between the δ-axis current i δ and rotor flux φ γ The actual torque response determined based on the product of γ The actual value will vary depending on the control state.

[0074] Considering this point, the response model unit S602 of this embodiment calculates the δ-axis current i δ , γ-axis current i γ , and rotor flux φ γ The response models S6021, S6022, and S6023 set individually for each are used to calculate the δ-axis current estimate i δ ^ , the estimated γ-axis current value i γ ^ and the rotor flux estimate φ corresponding to the actual rotor flux response γ ^ Calculate the following.

[0075] More specifically, in the response model section S602, the δ-axis current command value iδ * The torque current response model S6021 simulates the response of the actual δ-axis current to the γ-axis current command value i γ * An excitation current response model S6022 that simulates the response of the actual γ-axis current to the actual excitation current response, and a magnetic flux response model S6023 that simulates the actual rotor magnetic flux response to the actual excitation current response are individually set. Note that the torque current response model S6021, the excitation current response model S6022, and the magnetic flux response model S6023 are configured by transfer functions that reflect the actual δ-axis current response, the actual γ-axis current response, and the actual magnetic flux response, respectively, on the premise of the motor control system in this embodiment. In particular, the torque current response model S6021, the excitation current response model S6022, and the magnetic flux response model S6023 are configured by transfer functions that reflect the actual δ-axis current response, the actual γ-axis current response, and the actual magnetic flux response, respectively, on the premise of the motor control system in this embodiment. δ ,τ γ ,τ φ It is composed of a first-order low-pass filter with τ δ , τ γ , and τ φ are the δ-axis currents in the motor control system, respectively. δ , γ-axis current i γ , and rotor flux φ γ In particular, the time constant τ in the magnetic flux response model S6023 is set to an appropriate value based on the response characteristics of the φ is the rotor magnetic flux φ γ and γδ-axis current i γ ,i δ Considering the difference in response speed between δ and time constant τ γ This sets the γδ-axis current i γ ,i δ and rotor flux φ γ It is possible to determine response suggestion amounts for each current and magnetic flux that suitably reflect the difference in response characteristics of the two.

[0076] The calculation logic of the response model unit S602 described above can be expressed by the following equations (29) to (31).

[0077]

number

[0078] The response delay processing value calculation unit S603 calculates the δ-axis current estimated value i δ ^ and the rotor flux estimate φ γ ^ is input, and the map data stored in advance in the memory is referenced to obtain the response delay processing value T m2_pr * Calculate the response delay processing value T m2_pr * is the estimated δ-axis current value i δ ^ and the rotor flux estimate φ γ ^ are parameters corresponding to the command torque when the actual δ-axis current response and the actual rotor flux response are considered to be the actual δ-axis current response and the actual rotor flux response, respectively. m2_pr * is the δ-axis current i δ and rotor flux φ γ The second torque target value T is determined by taking into account the difference in response characteristics between m2 * is the correction value.

[0079] Instead of referring to map data, the estimated δ-axis current value i δ ^ and the rotor flux estimate φ γ ^ By applying this, the response delay processing value T m2_pr * Alternatively, a configuration may be adopted in which the following is calculated.

[0080] Returning to FIG. 5, the second filter processing unit S503 calculates a response delay processing value T equivalent to the torque command value calculated from each current estimation value. m2_pr * is processed by the same low-pass filter H(s) as the first filter processing unit S501 to obtain the second torque estimate T m2 ^ That is, the second torque estimate T m2 ^ is the response delay processing value T m2_pr * is calculated as a value corresponding to the actual torque response when is set as the torque command value.

[0081] The adder S504 calculates the second torque estimate T m2 ^ First torque estimate T m1 ^ is subtracted to obtain the estimated disturbance torque T d_e is calculated and output to the gain processing unit S402.

[0082] The disturbances in this embodiment include air resistance, modeling errors due to variations in vehicle mass caused by the number of occupants and the load, tire rolling resistance, gradient resistance, and the first torque estimate T m1 ^ and the second torque estimate T m2 ^ The disturbance torque estimation unit S401 of this embodiment estimates the second torque target value T m2 * and rotor mechanical angular velocity ω rm From the vehicle model, the transfer characteristic G p (s) based on the estimated disturbance torque T d_e In order to calculate the disturbance torque estimate T d_e can be determined.

[0083] Returning to FIG. 4, the gain processing unit S402 calculates the disturbance torque estimate T d_e is multiplied by a predetermined gain to obtain the torque correction value T c Then, the first torque target value T m1 * Torque correction value T c is added to obtain the second torque target value T m2 * and outputs it to the current command value calculation unit 117.

[0084] By performing the above processing, the δ-axis current i δ and rotor flux φ γ The operating point (especially the excitation current i fEven if variations in torque response occur depending on the control state (control state (1)), deterioration in the disturbance estimation accuracy can be suppressed.

[0085] [Second embodiment] In the electric vehicle control of this embodiment, in contrast to the electric vehicle control of the first embodiment described above, the response delay processing unit S502 (see FIG. 5) calculates the second torque target value T m2 * Instead, the measured δ-axis current i δ and γ-axis current i γ is used as input and the response delay processing value T m2_pr * The difference is that the above formula is calculated, but other processes are performed in the same way.

[0086] In particular, the response model unit S602 in the response delay processing unit S502 of this embodiment includes only the magnetic flux response model S6023 (it does not include the torque current response model S6021 or the excitation current response model S6022). γ is subjected to the same low-pass filter processing as in the first embodiment to obtain the rotor flux estimate value φ γ ^ Then, the response delay processing value calculation unit S603 calculates the measured δ-axis current i δ and the rotor flux estimate φ γ ^ , the response delay processing value T m2_pr * The following is established.

[0087] That is, the response delay processing unit S502 of this embodiment omits the processing in the current command value calculation unit S601, the torque current response model S6021, and the excitation current response model S6022, and calculates the δ-axis current i δ and the γ-axis current i γ The rotor flux estimate φ is determined directly from the measured value of γ ^ Response delay processing value T m2_pr * The following is established.

[0088] This allows the parameters indicating the actual torque current response and the actual rotor flux response to be obtained using simpler logic, while also allowing the appropriate response delay processing value T m2_pr * It is possible to realize a control logic for calculating

[0089] [Control results] The control results of the electric vehicle control method of each embodiment (Example) will be explained below while comparing them with the control results of the Reference Example. In the Reference Example, the second filter processing unit S503 calculates the second torque target value T without going through the process in the response delay processing unit S502 of FIG. 5 . m2 * The second torque estimate T m2 ^ The electric vehicle control method is assumed to be different in that the above-mentioned steps are determined, but other processes are executed in the same manner.

[0090] (Example) FIG. 7 is a timing chart showing the first control results of the embodiment and the comparative example. In FIG. 7 and FIG. 8 described later, the control results of the embodiment and the comparative example are shown by solid lines and dashed lines, respectively. In particular, the first control result is a decrease in the excitation current (γ-axis current i γ ) is not flowing, and at a predetermined timing (time t2), the first torque target value T m1 * Consider a first control scene in which

[0091] As shown in the figure, the first torque target value T m1 * is not input and the γ-axis current i γ When the value of the γ-axis current i γ The rotor flux φ generated by γ From this state, the positive first torque target value T m1 * When is input (time t2), the torque current (δ-axis current i δ ) and rotor flux φ γ changes from 0 to a positive value. At this time, the δ-axis current i δ and rotor flux φγ Due to the difference in response characteristics of the rotor magnetic flux φ γ is the δ-axis current i δ It changes slowly relative to

[0092] Here, the actual torque response of the drive motor 101 is the δ-axis current i δ and rotor flux φ γ (See equation (28)). Also, the δ-axis current i δ is the rotor flux φ γ In the first control scenario, the δ-axis current i δ and rotor flux φ γ Since an increase in δ-axis current i δ For the excitation current i f When this delay occurs, the actual torque response determined by the product of these two factors will deviate from the desired torque response (standard torque response) by a certain amount or more.

[0093] In the control of the comparative example, the δ-axis current i δ and rotor flux φ γ The second torque target value T m2 * to the second torque estimate T m2 ^ and the estimated disturbance torque T d_e Therefore, at least the first torque target value T m1 * In the fixed section after time t2 when the input is d_e As a result, the accuracy of the disturbance torque estimate T d_e The first torque target value T m1 * Correction for the final second torque target value T m2 * The calculation of the above is not performed properly, and unintended vibrations in the longitudinal acceleration of the vehicle occur between time t2 and time t3.

[0094] In contrast to this, in the embodiment, the δ-axis current i δ and rotor flux φγ The disturbance torque estimate T d_e Therefore, the estimation accuracy of the disturbance is ensured even in the first control scenario, and the first torque target value T m1 * As a result, unintended vibrations in the vehicle longitudinal acceleration between time t2 and time t3 are suppressed, and a favorable acceleration feeling of the electric vehicle 10 can be achieved.

[0095] 8 is a timing chart showing the second control results of the example and the comparative example. In particular, the second control result is the γ-axis current i γ When the first torque target value T m1 * Consider a second control scene where

[0096] In this case, from time t0 to time t2, the positive first torque target value T m1 * is input, and the γ-axis current i γ By manipulating the rotor flux φ γ is maintained at a predetermined value. From this state, at time t2, the first torque estimation value T m1 ^ When decreases, the δ-axis current i δ and rotor flux φ γ At this time, as in the first control scenario described above, the rotor magnetic flux φ γ is the δ-axis current i δ It changes slowly relative to

[0097] Here, in the second control scenario, the δ-axis current i δ and rotor flux φ γ Therefore, the actual torque response characteristics determined based on the product of these two factors are expected to decrease with the δ-axis current i δ Therefore, the influence of the response characteristics of the δ-axis current i δ and rotor flux φ γ The disturbance torque estimate Td_e Even in the control of the comparative example in which the above calculation is performed, no substantial error occurs, and the estimation accuracy of the disturbance is maintained.

[0098] On the other hand, the δ-axis current i δ and rotor flux φ γ Considering the difference in response characteristics of d_e Even in the control of the embodiment in which the above calculation is performed, the estimation accuracy of the disturbance in the second control scene is necessarily ensured.

[0099] Therefore, in the control of this embodiment, it is possible to ensure the accuracy of estimating the disturbance in both the first and second control scenarios, which have different characteristics of the actual torque response. That is, in the control of the electric vehicle 10 equipped with an induction motor, it is possible to ensure the accuracy of estimating the disturbance without depending on the motor operating point, and to achieve a favorable acceleration feeling.

[0100] [Action and effect] The configurations and the resulting effects of the above-described embodiments will now be described together.

[0101] In the above embodiment (first or second embodiment), an electric vehicle control method is provided for controlling an electric vehicle 10 equipped with a drive motor 101 configured as an induction motor as a driving source for traveling.

[0102] This electric vehicle control method calculates a first torque target value T based on vehicle information (vehicle speed V and accelerator opening APO). m1 * a first torque target value calculation step (S115) for calculating a disturbance torque T acting on the drive motor 101; d a disturbance torque estimation step (S401) for estimating a first torque target value T m1 * and disturbance torque T d to the second torque target value T m2 * a second torque target value calculation step (S116) for calculating the second torque target value T m2 * Based on this, the excitation current command value (γ-axis current command value iγ * and an excitation current command value calculation step (117) for calculating the excitation current command value.

[0103] In the disturbance torque estimation process, the γ-axis current command value i γ * Actual rotor flux response (rotor flux estimate φ γ ^ ) and the rotor flux estimate φ γ ^ Based on the second torque target value T m2 * The corrected second torque target value (response delay processing value T m2_pr * ) is calculated (S502), and the response delay processing value T m2_pr * Based on the disturbance torque T d is calculated (S504).

[0104] This allows the torque current (δ-axis current i δ ) and rotor flux φ γ Considering the difference in response characteristics between the disturbance torque T d and estimate the disturbance torque T d The second torque target value T m2 * Therefore, the operating point in the motor control system assuming an induction motor (especially the γ-axis current i γ Even if torque response variations (nonlinear torque response delay) occur depending on the control state of the d It is possible to ensure the estimation accuracy.

[0105] In the disturbance torque estimation process of the first embodiment, a speed parameter (rotor mechanical angular velocity ω rm ) based on the first torque target value T m1 * The first torque estimate T corresponds to the actual torque response according to m1 ^ (S501), and the calculated second torque target value Tm2 * is used as input and the rotor flux φ γ The actual rotor flux response (rotor flux estimated value φ γ ^ ) is calculated. Then, the rotor flux estimate φ γ ^ Based on this, the response delay processing value T m2_pr * The second torque estimate T corresponds to the actual torque response according to m2 ^ (S603), and the first torque estimate T m1 ^ and the second torque estimate T m2 ^ from the disturbance torque T d is calculated (S504).

[0106] This allows for a more specific control logic for estimating the disturbance. In particular, the first torque estimate T m1 ^ is the first torque target value T m1 * The second torque estimate T m2 ^ The second torque target value T m2 * (the torque target value that takes into account the influence of disturbances on the basic torque target value) is corrected to take into account the difference in response characteristics described above (the response delay processing value T m2_pr ) can be determined from the first torque estimate T m1 ^ The second torque estimate T has a small phase shift m2 ^ can be determined, and the accuracy of disturbance estimation can be further improved.

[0107] In the disturbance torque estimation step of the first embodiment, the torque current command value (δ-axis current command value i δ * ) and the γ-axis current command value iγ * An excitation current response model S6022 that simulates the response of the actual excitation current to the actual excitation current, and a magnetic flux response model S6023 that simulates the response of the actual rotor magnetic flux to the actual excitation current are set.

[0108] In particular, the second torque target value T m2 * Based on the previous value of δ * and γ-axis current command value i γ * (S601), and the δ-axis current command value i δ * By applying the torque current response model S6021 to δ * The torque current estimate (δ-axis current estimate i δ ^ ) and calculates the γ-axis current command value i γ * By applying the excitation current response model S6022 to γ * The excitation current estimate (γ-axis current estimate i γ ^ ) and calculate the estimated γ-axis current value i γ ^ By applying the flux response model S6023 to the rotor flux, the rotor flux estimate value φ γ ^ Furthermore, the estimated δ-axis current value i δ ^ and the rotor flux estimate φ γ ^ to the second torque estimate T m2 ^ is calculated (S603).

[0109] As a result, the δ-axis current i δ and rotor flux φ γ The second torque estimate T is calculated from the individual parameters that indicate the response characteristics of each of the m2 ^ Therefore, the δ-axis current i δ and rotor flux φγ While more appropriately reflecting the difference in response characteristics of the disturbance torque T d An arithmetic logic that can determine:

[0110] In particular, the torque current response model S6021, the excitation current response model S6022, and the magnetic flux response model S6023 each have an individual time constant (τ δ , τ γ , and τ φ ) is composed of a low-pass filter.

[0111] As a result, the δ-axis current i δ and rotor flux φ γ The second torque estimate T m2 ^ It is possible to realize a simpler calculation logic for calculating

[0112] In the disturbance torque estimation process of the second embodiment, a speed parameter (rotor mechanical angular velocity ω rm ) based on the first torque target value T m1 * The first torque estimate T corresponds to the actual torque response according to m1 ^ (S501). Furthermore, the torque current (δ-axis current i δ ) is defined as the actual torque current response, and the excitation current (γ-axis current i γ ) is defined as the actual excitation current response. δ and the γ-axis current i γ Based on the measured value, the response delay processing value T m2_pr * The second torque estimate T corresponds to the actual torque response according to m2 ^ (S603), and the first torque estimate T m1 ^ and the second torque estimate T m2 ^ from the disturbance torque T d is calculated (S504).

[0113] This allows the first torque estimate T m1 ^ The second torque estimate T has a small phase shift m2 ^ It is possible to realize an operational logic for determining

[0114] Furthermore, in the above embodiment (first or second embodiment), a motor controller 107 is provided that functions as an electric vehicle control device suitable for executing the above electric vehicle control method.

[0115] In particular, the motor controller 107 determines the first torque target value T based on the vehicle information (vehicle speed V and accelerator opening APO). m1 * a first torque target value calculation unit S115 that calculates a disturbance torque T acting on the drive motor 101; d a disturbance torque estimation unit S401 that estimates a first torque target value T m1 * and disturbance torque T d to the second torque target value T m2 * a second torque target value calculation unit S116 that calculates the second torque target value T m2 * Based on the excitation current command value i f * and an excitation current command value calculation unit (current command value calculation unit 117) that calculates:

[0116] Then, the disturbance torque estimation unit S401 calculates the γ-axis current command value i γ * Actual rotor flux response (rotor flux estimate φ γ ^ ) and the rotor flux estimate φ γ ^ Based on the second torque target value T m2 * The corrected second torque target value (response delay processing value T m2_pr * ) is calculated (S502), and the response delay processing value Tm2_pr * Based on the disturbance torque T d is calculated (S504).

[0117] The above describes embodiments of the present invention, but the above embodiments merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. [Explanation of symbols]

[0118] 10 Electric vehicle, 101 Drive motor, 107 Motor controller, S115 First torque target value calculation unit, S116 Second torque target value calculation unit, S401 Disturbance torque estimation unit, S502 Response delay processing unit, S601 Current command value calculation unit, S602 Response model unit, S603 Processed value calculation unit

Claims

1. An electric vehicle control method for controlling an electric vehicle equipped with a drive motor configured as an induction motor as a driving source for traveling, comprising: a first torque target value calculation step of calculating a first torque target value based on vehicle information; a disturbance torque estimating step of estimating a disturbance torque acting on the drive motor; a second torque target value calculation step of calculating a second torque target value from the first torque target value and the disturbance torque; an excitation current command value calculation step of calculating an excitation current command value based on the second torque target value; Including, In the disturbance torque estimation step, defining an actual rotor flux response as a response of the actual rotor flux to the excitation current command value; determining a corrected second torque target value, which is a correction value of the second torque target value, based on the actual rotor magnetic flux response; calculating the disturbance torque based on the corrected second torque target value; Electric vehicle control method.

2. 2. The electric vehicle control method according to claim 1, In the disturbance torque estimation step, calculating a first torque estimate value corresponding to an actual torque response according to the first torque target value based on a speed parameter proportional to a vehicle speed of the electric vehicle; Using the calculated second torque target value as an input, a response model reflecting a response characteristic of the rotor flux is applied to obtain the actual rotor flux response; calculating a second torque estimate value corresponding to an actual torque response according to the corrected second torque target value based on the actual rotor flux response; calculating the disturbance torque from the first torque estimate value and the second torque estimate value; Electric vehicle control method.

3. 3. The electric vehicle control method according to claim 2, As the response models, a torque current response model that simulates the response of an actual torque current to a torque current command value, an excitation current response model that simulates the response of the actual excitation current to the excitation current command value, and a magnetic flux response model that simulates the response of the actual rotor magnetic flux to the actual excitation current are set, calculating the torque current command value and the excitation current command value based on the previous value of the second torque target value; calculating a torque current estimated value as an actual torque current response to the torque current command value by applying the torque current response model to the torque current command value; calculating an excitation current estimation value as an actual excitation current response to the excitation current command value by applying the excitation current response model to the excitation current command value; calculating a rotor flux estimation value as the actual rotor flux response by applying the flux response model to the excitation current estimation value; calculating the second torque estimate from the torque current estimate and the rotor magnetic flux estimate; Electric vehicle control method.

4. 4. The electric vehicle control method according to claim 3, the torque current response model, the excitation current response model, and the magnetic flux response model are configured by low-pass filters having different time constants, respectively; Electric vehicle control method.

5. 2. The electric vehicle control method according to claim 1, In the disturbance torque estimation step, calculating a first torque estimate value corresponding to an actual torque response according to the first torque target value based on a speed parameter proportional to a vehicle speed of the electric vehicle; The measured torque current is specified as the actual torque current response, The measured value of the excitation current is specified as the actual excitation current response, calculating a second torque estimate value corresponding to an actual torque response according to the corrected second torque target value using the measured value of the torque current and the measured value of the excitation current as inputs; calculating the disturbance torque from the first torque estimate value and the second torque estimate value; Electric vehicle control method.

6. An electric vehicle control device that controls an electric vehicle equipped with a drive motor configured as an induction motor as a driving source, a first torque target value calculation unit that calculates a first torque target value based on vehicle information; a disturbance torque estimating unit that estimates a disturbance torque acting on the drive motor; a second torque target value calculation unit that calculates a second torque target value from the first torque target value and the disturbance torque; an excitation current command value calculation unit that calculates an excitation current command value based on the second torque target value; and The disturbance torque estimation unit defining an actual rotor flux response as a response of the actual rotor flux to the excitation current command value; determining a corrected second torque target value, which is a correction value of the second torque target value, based on the actual rotor magnetic flux response; calculating the disturbance torque based on the corrected second torque target value; Electric vehicle control device.

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