Method of controlling an electric motor and electric motor system

Abstract

A control method of a motor of one embodiment of the present application controls the motor by voltage phase control based on a voltage command value indicating the magnitude of the voltage to be supplied to the motor and a voltage phase command value indicating the phase of the voltage. In the control method of the motor, a required time required when a final command value of the voltage applied to the motor by the voltage phase control is calculated using a rotational frequency parameter related to the rotational frequency of the motor is obtained. Then, the rotational frequency parameter is detected, and the detected rotational frequency parameter is changed based on the required time. After that, the final command value is calculated using the changed rotational frequency parameter according to the command value calculation model.

Description

Technical Field

[0001] This invention relates to a control method and system for an electric motor. Background Technology

[0002] In recent years, electric motors have been controlled using pulse width modulation (PWM). Additionally, sometimes the motor is controlled in an overmodulation state where the modulation factor of the PWM is set to a value greater than 1. The overmodulation state, by increasing the modulation factor, results in a rectangular wave state where the waveform of the voltage applied to the motor from the inverter is essentially a rectangular wave.

[0003] In overmodulation mode, the voltage rating of the power supplied from the inverter to the motor becomes saturated, so the phase of the voltage applied to the motor from the inverter is essentially a controllable parameter. On the other hand, in non-overmodulation mode with a modulation factor of 1 or less, both the voltage rating and the voltage phase can be controlled. Therefore, compared to controlling the motor in non-overmodulation mode, the motor's controllability decreases when controlling the motor in overmodulation mode. As a result, for example, when the motor speed changes abruptly, overcurrent may sometimes flow in the motor.

[0004] Thus, techniques for preventing overcurrent caused by sudden changes in motor speed are known. For example, JP2006-320039A discloses the following: when controlling a motor in an overmodulated state, the motor speed is detected, and the voltage applied to the motor from the inverter is corrected based on the detected motor speed.

[0005] The electric motor control method described in JP2006-320039A adjusts the voltage applied to the motor according to the motor speed as described above, thereby appropriately controlling the amount of current flowing through the motor when the motor speed changes abruptly in an overmodulated state.

[0006] However, this control method does not consider the response delay that occurs during the period between detecting the motor speed and applying voltage to the motor based on the detected motor speed. Therefore, in this control method, when the motor speed changes abruptly under overmodulation conditions, overcurrent can still occur in the motor. Furthermore, if the voltage applied to the motor is excessively compensated to reliably prevent overcurrent, the voltage applied to the motor will be insufficient under normal conditions other than sudden changes in motor speed. Therefore, the motor control method described in JP2006-320039A sometimes fails to properly control the motor. Summary of the Invention

[0007] The purpose of this invention is to provide a method for controlling an electric motor and an electric motor system that can properly control the motor even in an overmodulated state by taking into account the response delay that occurs during the period before voltage is applied to the motor.

[0008] One aspect of the present invention provides a motor control method that controls the motor using voltage phase control based on a voltage norm command value representing the magnitude of the voltage to be supplied to the motor and a voltage phase command value representing the phase of that voltage. In this motor control method, the required time for calculating the final command value of the voltage applied to the motor via voltage phase control is obtained according to a command value calculation model that uses a speed parameter related to the motor's speed. Furthermore, the speed parameter is detected and changed based on the required time. Then, the command value calculation is performed using the changed speed parameter to calculate the final command value. Attached Figure Description

[0009] Figure 1 This is a block diagram showing the structure of the electric motor system according to the first embodiment.

[0010] Figure 2 This is a block diagram showing the partial structure of the current vector control unit used to generate the d-axis voltage command value in current vector control.

[0011] Figure 3 This is a block diagram showing the structure of the voltage phase control unit.

[0012] Figure 4 It is a graph used to represent the setting of the voltage phase range in voltage phase control.

[0013] Figure 5 This is a block diagram showing the structure of the phase change section.

[0014] Figure 6 This is a block diagram representing the structure of the switching decision unit.

[0015] Figure 7 This is an explanatory diagram showing the method for determining the control mode in the control mode determination unit.

[0016] Figure 8 It is a block diagram representing the structure of the output controller.

[0017] Figure 9 This is a flowchart of the motor control in this embodiment.

[0018] Figure 10 This is a flowchart of voltage phase control.

[0019] Figure 11It is a graph representing (A) electric angular velocity, (B) electric angular acceleration, (C) the current flowing through the motor, and (D) the voltage applied to the motor.

[0020] Figure 12 This is a block diagram showing the structure of the phase change section in the modified example. Detailed Implementation

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] Figure 1 This is a block diagram showing the structure of the electric motor system in the first embodiment. For example... Figure 1 As shown, the motor system 100 includes: a motor 9 as the controlled object; circuitry for controlling the motor 9; detectors for detecting parameters required for controlling the motor 9; and a battery 15. Specifically, the motor system 100 includes: a current vector control unit 1, a voltage phase control unit 2, an output controller 3, a converter 4, a pulse width modulation signal generator 5, and an inverter 6. Furthermore, the motor system 100 also includes a battery voltage detector 7, a current detector 8, a rotor detector 10, a speed calculator 11, a converter 12, and a control mode switching determination unit 13.

[0023] Of the components constituting the electric motor system 100, the parts other than the electric motor 9 are control devices configured to control the electric motor 9. The battery voltage detector 7, current detector 8, and rotor detector 10 are detectors that detect parameters required for controlling the electric motor 9. The current vector control unit 1, voltage phase control unit 2, and control mode switching determination unit 13 constitute a controller (control unit). The controller is, for example, a computer composed of a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and input / output interface (I / O interface). The controller is configured to determine the control mode of the electric motor 9, change the control mode of the electric motor 9 as needed, and control the operation of the electric motor 9 by determining the control mode, etc. Furthermore, the controller is programmed to execute the processing required to implement these processes at predetermined operation cycles. Additionally, the aforementioned controller, output controller 3, converter 4, pulse width modulation signal generator 5, inverter 6, speed calculator 11, and converter 12 are circuit types for controlling the electric motor system 100.

[0024] Furthermore, the electric motor 9 in this embodiment is an IPM (Interior Permanent Magnet) type synchronous motor with multi-phase windings. In this embodiment, the windings of the electric motor 9 are three phases: U-phase, V-phase, and W-phase. That is, the electric motor 9 is a three-phase synchronous motor. Additionally, the electric motor 9 is driven by pulse width modulation control. Furthermore, the electric motor system 100 is, for example, assembled in an automobile. Moreover, in an automobile equipped with the electric motor system 100, the electric motor 9 can function as a driving force source and / or a generator for the automobile.

[0025] The current vector control unit 1 performs current vector control. Current vector control is one of the control modes of the motor 9. In current vector control, a vector (hereinafter referred to as the current vector) related to the current supplied to the motor 9 is controlled. In current vector control, the current vector is adjusted to make the torque generated by the motor 9 converge to its target value (hereinafter referred to as the torque target value T*).

[0026] More specifically, the current vector control unit 1 receives the target torque value T*, the rotational speed N [rpm] of the motor 9, and the DC voltage V of the battery 15. dc The input. Additionally, the d-axis current i of the motor 9 is fed back to the current vector control unit 1. d and q-axis current i q Then, based on these inputs, the current vector control unit 1 calculates the d-axis voltage command value V. di_fin * and q-axis voltage command value V qi_fin *. d-axis voltage command value V for current vector control. di_fin * and q-axis voltage command value V qi_fin *This is input to output controller 3. In current vector control, motor 9 is based on this d-axis voltage command value V. di_fin * and q-axis voltage command value V qi_fin * is controlled, and thus the torque generated by the motor 9 converges to the target torque value T*.

[0027] Additionally, the d-axis voltage command value V di_fin * represents the command value for the voltage along the d-axis in current vector control. Similarly, the command value for the q-axis voltage is V. qi_fin * represents the command value for the voltage on the q-axis in current vector control.

[0028] In addition, the current vector control unit 1 sets the d-axis voltage command value V di_fin * and q-axis voltage command value V qi_fin During the generation of *, the target value of the d-axis current i is calculated. d * and the target value of the q-axis current i q * d-axis current target value i d* represents the target value of the d-axis component in the current vector. Similarly, the target value of the q-axis current is i. q * represents the target value of the q-axis component in the current vector. The target value of the d-axis current is i. d * and q-axis current target value i q *It is output to the voltage phase control unit 2.

[0029] Furthermore, regarding the specific structure of the current vector control unit 1, and the d-axis voltage command value V in the current vector control... di_fin * and q-axis voltage command value V qi_fin The calculation method for * will be described in detail later.

[0030] The voltage phase control unit 2 performs voltage phase control. Voltage phase control is one of the control modes of the motor 9. In voltage phase control, the phase of the voltage supplied to each phase of the motor 9 (hereinafter referred to as the phase-to-phase voltage) is controlled. In voltage phase control, the phase of the phase-to-phase voltage is adjusted so that the torque generated by the motor 9 converges to the target torque value T*.

[0031] More specifically, the voltage phase control unit 2 receives the target torque value T*, the rotational speed N of the motor 9, and the DC voltage V of the battery 15. dc d-axis current target value i d * Target value of q-axis current i q * Input. Additionally, the d-axis current i is fed back to the voltage phase control unit 2. d and q-axis current i q Then, the voltage phase control unit 2 outputs the d-axis voltage command value V to the output controller 3 based on these inputs. dv_fin * and q-axis voltage command value V qv_fin *

[0032] Additionally, the d-axis voltage command value V dv_fin * represents the command value for the d-axis voltage in voltage phase control. Similarly, the q-axis voltage command value V... qv_fin * represents the command value for the q-axis voltage in voltage phase control. This relates to the specific structure of the voltage phase control unit 2 and the d-axis voltage command value V in voltage phase control. dv_fin * and q-axis voltage command value V qv_fin The calculation method for * will be described in detail later.

[0033] Input the d-axis voltage command value V in the current vector control to the output controller 3. di_fin * and q-axis voltage command value V qi_fin * and the d-axis voltage command value V in voltage phase control. dv_fin * and q-axis voltage command value V qv_fin* Additionally, the control mode switching determination unit 13 inputs a control mode signal Sm to the output controller 3 as a determination result. Furthermore, based on the control mode signal Sm, the output controller 3 selects either current vector control or voltage phase control as the control mode for the motor 9. The output controller 3 uses the d-axis voltage command value and q-axis voltage command value of the selected control mode as the final d-axis voltage command value V, respectively. d_fin * and the final voltage command value V for the q-axis q_fin * Output to converter 4. d-axis final voltage command value V d_fin * represents the final commanded value of the voltage applied to the motor along the d-axis. Similarly, the final commanded voltage value V for the q-axis is... q_fin * represents the final command value of the voltage applied in the q-axis direction of motor 9. The structure of output controller 3 and the generation of control mode signal Sm will be described in detail later.

[0034] Converter 4 transforms the voltage command value in the dq-axis coordinate system into the voltage command value in the UVW three-phase coordinate system. That is, converter 4 transforms the final voltage command value V on the d-axis... d_fin *and the final voltage command value V for the q-axis q_fin *Converted to three-phase voltage command value (V) u *、V v *、V w *). The three-phase voltage command value is the command value that determines the voltage of each phase of UVW. The converter 4 performs this coordinate transformation based on the electrical angle θ of the motor 9, as shown in equation (1). In addition, the converter 4 outputs the three-phase voltage command value to the pulse width modulation signal generator 5.

[0035] (Equation 1):

[0036]

[0037] The pulse width modulation signal generator 5 is based on the three-phase voltage command value and the DC voltage V of the battery 15. dc Generates a pulse width modulation signal (D uu *、D ul *、D vu *、D vl *, D wu *、D wl *). The pulse width modulation signal (hereinafter referred to as the PWM signal) is the drive signal for the power elements of inverter 6. Therefore, the pulse width modulation signal is input to inverter 6.

[0038] Inverter 6 uses a PWM signal to convert the DC voltage V of battery 15. dc Transformed into a three-phase AC voltage (V) for driving motor 9 u Vv V w A three-phase alternating voltage is applied to the motor 9. As a result, current flows through each phase of the motor 9. The currents flowing through phases U, V, and W are alternating currents i. u i v i w (Hereinafter referred to as three-phase alternating current). As a result, motor 9 is driven based on the PWM signal, generating torque.

[0039] The battery voltage detector 7 detects the voltage of the battery 15 connected to the inverter 6. In this embodiment, the battery voltage detector 7 detects the DC voltage V of the battery 15. dc The detected DC voltage V dc It is output to the current vector control unit 1, the voltage phase control unit 2, and the control mode switching determination unit 13.

[0040] Current detector 8 detects the current supplied from inverter 6 to motor 9. In this embodiment, current detector 8 detects the three-phase alternating current (i... u i v i w The alternating current of at least two phases of the phase is measured. In this embodiment, the current detector 8 detects the alternating current i of phase U. u The AC current iv of phase V is detected. The detected values ​​of the three-phase AC current are input to converter 12.

[0041] Rotor detector 10 detects the electrical angle θ of motor 9. The detected electrical angle θ is input to converter 4 and converter 12 respectively. In addition, the electrical angle θ is input to speed calculator 11.

[0042] Rotational speed calculator 11 is based on electrical angle θ in unit time Δt Nave The changes in the values ​​of the electric motor 9 include the rotational speed N (mechanical angular speed) and electrical angular velocity ω. e Rotational speed N and electrical angular velocity ω e This is a speed parameter related to the rotational speed N of the motor 9. The speed parameter is the rotational speed N or a parameter calculated using the rotational speed N. More specifically, the speed calculator 11 detects the rotational speed N of the motor 9. Furthermore, the speed calculator 11 calculates the electrical angular velocity ω by performing a unit conversion of the rotational speed N using the number of pole pairs of the motor 9. e Unit time Δt Nave This is the calculation cycle (operation cycle) of the speed calculator 11, which is a predetermined value. The speed N is input to the current vector control unit 1, the voltage phase control unit 2, and the control mode switching determination unit 13. The electric angular velocity ω... e It is input to the voltage phase control unit 2.

[0043] The converter 12 uses the electrical angle θ detected by the rotor detector 10 to convert the three-phase AC current detected by the current detector 8 into current in the dq-axis coordinate system. In this embodiment, the current detector 8 detects the AC current i of phase U. u and the alternating current i of phase V v Therefore, the transformer 12 performs the above coordinate transformation according to the following equation (2).

[0044] (Equation 2):

[0045]

[0046] The control mode switching determination unit 13 determines the control mode of the motor 9 suitable for its operating state (so-called operating point or running point) based on the motor 9's operating state. Parameters representing the operating state of the motor 9 include, for example, the d-axis current i. d d-axis current target value i d * d-axis final voltage command value V d_fin *, q-axis current i q Target value of q-axis current i q * q-axis final voltage command value V q_fin *etc. Additionally, the DC voltage V of battery 15... dc Rotational speed N and electrical angular velocity ω e These parameters also represent the operating state of the motor 9. In this embodiment, the control mode switching determination unit 13 determines the operating state based on the final voltage command value V of the d-axis. d_fin * q-axis final voltage command value V q_fin *, d-axis current i d Rotational speed N and DC voltage V dc The control mode of motor 9 is determined. The control mode switching determination unit 13 outputs the determination result of the control mode, i.e., the control mode signal Sm, to the current vector control unit 1, the voltage phase control unit 2, and the output controller 3.

[0047] As described above, the motor system 100 is a system that drives the motor 9 through pulse width modulation control. Furthermore, the motor system 100 appropriately switches the control mode of the motor 9 between current vector control and voltage phase control according to the operating state of the motor 9.

[0048] The following is a detailed description of the specific structure of each part of the electric motor system 100.

[0049] (Current Vector Control)

[0050] Figure 2 This represents the d-axis voltage command value V used in the current vector control unit 1 to generate the current vector control. di_fin*A block diagram of the partial structure (d-axis voltage command value calculation unit). For example... Figure 2 As shown, the current vector control unit 1 includes: a non-interference voltage calculation unit 21, an LPF (low-pass filter) 22, a current target value calculation unit 23, a subtractor 24, a PI control unit 25, and an adder 26.

[0051] The non-interference voltage calculation unit 21 calculates the target torque value T*, rotational speed N, and DC voltage V of the battery 15. dc Calculate the non-interference voltage V d_dcpl *. Non-interference voltage V d_dcpl * Output to LPF22. Non-interference voltage V d_dcpl * is the voltage value used to eliminate mutual interference between the d-axis and q-axis (hereinafter referred to as interference voltage).

[0052] For example, a non-interference table (not shown) is stored in the non-interference voltage calculation unit 21. The non-interference table pre-calculates the non-interference voltage V for each operating state of the motor 9. d_dcpl *Corresponding lookup table. In the non-interference table, the operating status of motor 9 is determined by, for example, the target torque value T*, speed N, and DC voltage V of battery 15. dc Confirmed. Thus, when the non-interference voltage calculation unit 21 has a non-interference meter, the non-interference voltage calculation unit 21 acquires the target torque value T*, the rotational speed N, and the DC voltage V of the battery 15. dc Then, the non-interference voltage calculation unit 21 calculates (obtains) the non-interference voltage V corresponding to the operating state of the motor 9 by referring to the non-interference table. d_dcpl * Additionally, the non-interference voltage V stored in the non-interference table d_dcpl *Based on the target d-axis current i when motor 9 generates the torque specified by the target torque value T* at maximum efficiency. d *And predetermined. Additionally, the non-interference voltage V d_dcpl *Based on pre-determined factors such as experiments.

[0053] The LPF22 is a low-pass filter that takes into account the case where the interference voltage depends on the current. The time constant of the LPF22 is set to ensure the responsiveness of the target d-axis current. The non-interference voltage V after processing by the LPF22 d_dcpl_flt It was input into the addition section 26.

[0054] The current target value calculation unit 23 calculates the target torque value T*, the rotational speed N, and the DC voltage V of the battery 15. dc Calculate the target value of the d-axis current i d * d-axis current target value i d * is output to subtractor 24. Additionally, the target value of the d-axis current i... d *It is output to the voltage phase control unit 2.

[0055] For example, an ammeter (not shown) is stored in the current target value calculation unit 23. The ammeter stores the d-axis current target value i for each operating state (operating point) of the motor 9. d The table shows the operating status of the motor 9, for example, the target torque value T*, the rotational speed N, and the DC voltage V of the battery 15. dc Confirmed. Thus, when the current target value calculation unit 23 has an ammeter, the current target value calculation unit 23 acquires the torque target value T*, the rotational speed N, and the DC voltage V of the battery 15. dc Then, the current target value calculation unit 23 calculates (obtains) the d-axis current target value i corresponding to the operating state of the motor 9 by referring to the ammeter. d * Additionally, the target d-axis current value i stored in the ammeter. d * is the value of the torque specified by the torque target value T* for the electric motor 9 to generate the torque at maximum efficiency, which is determined in advance through experiments, etc.

[0056] Subtractor 24 calculates the d-axis current deviation. The d-axis current deviation is the deviation between the target value and the actual detected value of the d-axis current. In this embodiment, subtractor 24 calculates the deviation from the target value i of the d-axis current. d Subtract the d-axis current i, which is used as the detection value, from the middle. d To calculate the d-axis current deviation (i d *-i d The d-axis current deviation is input to the PI control unit 25.

[0057] The PI control unit 25 calculates the current feedback voltage command value V for the d-axis using PI (Proportional-Integral) control that feeds back the d-axis current deviation. di In this embodiment, the PI control unit 25 calculates the current feedback voltage command value V according to the following formula (3). di ′。 In formula (3), “K” dp " is the proportional gain used on the d-axis. Additionally, in equation (3), "K" di "This is the integral gain used for the d-axis. The gains of these PI controls are predetermined based on experiments, etc. The current feedback voltage command value V used for the d-axis..." di ′ is input into addition section 26.

[0058] (Equation 3):

[0059]

[0060] As shown in equation (4), the adder 26 inputs the non-interference voltage V processed by LPF22. d_dcpl_flt With current feedback voltage command value Vdi The values ​​are added together to calculate the d-axis voltage command value V in current vector control. di_fin *

[0061] (Equation 4):

[0062] V di_fin * =V d_dcpl_flt +V di ′ (4)

[0063] As described above, the current vector control unit 1 feeds back the d-axis current i d The d-axis voltage command value V in operational current vector control di_fin * This current vector control is suitable for controlling the motor 9 when the voltage rating of the power supplied to the motor 9 is not saturated, and the voltage rating can be changed as required.

[0064] Furthermore, this section explains the specific structure of the current vector control unit 1, including the generation of the d-axis voltage command value V in current vector control. di_fin * This is part of the d-axis voltage command value calculation unit. However, it is used to generate the q-axis voltage command value V in current vector control. qi_fin The part described above, *, is configured similarly to the d-axis voltage command value calculation unit. That is, the current vector control unit 1 is used to generate the q-axis voltage command value V in current vector control. qi_fin The structure includes a q-axis voltage command value calculation unit. This unit comprises: a non-interference voltage calculation unit, an LPF (Low Voltage Filter), a current target value calculation unit, a subtraction unit, a PI control unit, and an addition unit. Furthermore, except for the fact that it is used for the q-axis, each part of the q-axis voltage command value calculation unit has the same structure as the aforementioned d-axis voltage command value calculation unit.

[0065] (Voltage phase control)

[0066] Figure 3 This is a block diagram showing the structure of the voltage phase control unit 2. The voltage phase control unit 2 includes: (a) a voltage rating determination unit, (b) a voltage phase determination unit, and (c) a voltage command value calculation unit.

[0067] (a) The voltage rating determination unit is configured to determine the voltage rating of the power supplied to the motor 9 during voltage phase control. Specifically, the voltage rating determination unit consists of... Figure 3 The voltage rating command value generation unit, flux feedback control unit, voltage rating synthesis unit 40, and voltage rating limiting unit 41 shown are configured as follows: Specifically, the voltage rating command value generation unit consists of... Figure 3 The voltage rating upper limit calculation unit 31, phase change unit 32, induced voltage calculation unit 33, and feedforward voltage rating command value calculation unit 34 are shown. Specifically, the flux feedback control unit consists of... Figure 3 The unit shown comprises a reference current calculation unit 35, a magnetic flux calculation unit 36, a magnetic flux estimation unit 37, a magnetic flux deviation calculation unit 38, and a PI control unit 39.

[0068] (b) The voltage phase determination unit is configured to determine the phase of the voltage applied to the motor 9 during voltage phase control. Specifically, the voltage phase determination unit consists of... Figure 3 The voltage phase command value generation unit 42, torque feedback control unit, phase synthesis unit 47, and phase limiting unit 48 shown are constituted. Specifically, the torque feedback control unit consists of... Figure 3 The unit shown comprises a reference torque generation unit 43, a torque estimation unit 44, a torque deviation calculation unit 45, and a PI control unit 46.

[0069] (c) The voltage command value calculation unit calculates the d-axis voltage command value V in voltage phase control. dv_fin * and q-axis voltage command value V qv_fin * These values ​​are calculated based on the voltage rating determined by the voltage rating determination unit and the voltage phase determined by the voltage phase determination unit. Specifically, the voltage command value calculation unit consists of... Figure 3 The vector transformation unit 49 and the stabilizing filter 50 shown are configured.

[0070] (a-1) Voltage Rated Command Value Generation Unit

[0071] The voltage rating command value generation unit generates a feedforward voltage rating command value (hereinafter referred to as FF voltage rating command value V) through feedforward control. a_ff ). FF voltage rating command value V a_ff This is the command value that determines the magnitude of the voltage applied to motor 9 in voltage phase control. Additionally, the FF voltage rating command value V... a_ff The voltage rating is the basic target value determined by the operating state of the motor 9. In this embodiment, the voltage rating command value V generated by the voltage rating command value generation unit is... a_ff This is the basic target value (so-called basic value) of the voltage rating in voltage phase control. Therefore, the rating of the voltage actually applied to the motor 9 is limited by the voltage rating synthesis unit 40 and the voltage rating limiting unit 41.

[0072] FF voltage rating command value V a_ff This is equivalent to the instruction value of the modulation factor M specified in the PWM control (hereinafter referred to as the modulation factor instruction value M*). Therefore, the FF voltage rating instruction value V generated by the voltage rating instruction value generation unit... a_ff This is equivalent to the basic target value (reference modulation factor) of the modulation factor M. The modulation factor command value M* can be set arbitrarily. For example, the modulation factor command value M* can use the DC voltage V of battery 15. dc And the voltage rating command value V, which will be discussed later.a * is used for calculation. For example, the modulation factor command value M* is calculated according to... V a *Calculated. In this embodiment, the modulation factor M of the PWM control is the amplitude "Amp" of the fundamental component relative to the DC voltage V of the battery 15. dc The ratio (|Amp / V) dc |). The fundamental component is the fundamental frequency component among the frequency components contained in the waveform of the phase-to-phase voltage to be applied to motor 9.

[0073] In the non-overmodulation state (normal pulse width modulation state) where the modulation factor M is less than 1, the fundamental component of the correlated voltage becomes an analog sine wave. Furthermore, the lower limit of the modulation factor M is 0.

[0074] On the other hand, in the overmodulation state where the modulation factor M exceeds 1, the power elements of the inverter 6 do not switch around the maximum and minimum values ​​of the fundamental component. Therefore, in the overmodulation state, the waveform of the correlated voltage becomes a waveform with the areas around the maximum and minimum values ​​of the fundamental component removed. Furthermore, in the overmodulation state, the waveform of the correlated voltage contains higher harmonic components. Moreover, in the overmodulation state, when the modulation factor M is, for example, about 1.1 or more, the waveform of the correlated voltage essentially becomes a rectangular wave. That is, in extreme cases, the overmodulation state includes a rectangular wave state where the waveform of the correlated voltage essentially becomes a rectangular wave.

[0075] As described above, the voltage quota instruction value generation unit consists of a voltage quota upper limit calculation unit 31, a phase change unit 32, an induced voltage calculation unit 33, and a feedforward voltage quota instruction value calculation unit 34.

[0076] Voltage rating upper limit calculation unit 31 is based on the DC voltage V of battery 15 dc The upper limit of the voltage rating V is calculated using the modulation factor command value M*. a_upper Voltage rating upper limit V a_upper The voltage rating command value V for FF a_ff and voltage rating instruction value V a * Upper limit value. Voltage rating upper limit value V a_upper For example, according to Calculated using M*. Voltage rating upper limit V. a_upper It is input to the feedforward voltage rating instruction calculation unit 34.

[0077] Phase change unit 32 changes the electric angular velocity ω e The phase. More specifically, the phase change unit 32 is for calculating the d-axis voltage command value V. dv_fin * and q-axis voltage command value V qv_fin*The predetermined command value calculation model (the structure of the voltage phase control unit 2) obtains data including the detected electrical angular velocity ω. e The specified required time T, such as the time required from the start to the calculation of these instruction values. s Time required T s This is typically minimized when designing the instruction-value computation model. Then, based on the required time T... s Change the electric angular velocity ω e The phase. More specifically, the phase changing unit 32 changes the electrical angular velocity ω. e absolute value |ω e The phase of | is ahead (shifted forward), and the absolute value of the electric angular velocity after the phase change is calculated as |ω. e (Hereinafter referred to simply as "electric angular velocity after phase change"). The structure of the phase change unit 32 and the method of phase change will be described in detail later. Electric angular velocity after phase change |ω e ′| Input to the induced voltage calculation unit 33.

[0078] The induced voltage calculation unit 33 uses the reference magnetic flux rating φ described later. 0_ref and the electric angular velocity ω after phase change e ′, calculate the reference induced voltage V a0 In this embodiment, the induced voltage calculation unit 33 calculates the reference magnetic flux rating φ. 0_ref With the phase-changed electric angular velocity ω e Multiply by ' to calculate the reference induced voltage V'. a0 The calculated reference induced voltage V a0 It is input to the feedforward voltage rating instruction calculation unit 34.

[0079] The feedforward voltage rating instruction calculation unit 34 uses the upper limit value of the voltage rating V. a_upper and reference induced voltage V a0 To calculate the FF voltage rating command value V a_ff Specifically, the feedforward voltage rating instruction value calculation unit 34 is equipped with a function to calculate the upper limit value V of the voltage rating. a_upper and reference induced voltage V a0 It is composed of the minimum function (min) as the independent variable, and the upper limit of the output voltage rating V a_upper and reference induced voltage V a0 The smaller one is used as the FF voltage rating command value V. a_ff Therefore, in principle, the reference voltage V is used. a0 The voltage rating command value V for FF a_ff However, when the reference induced voltage V a0 Exceeding the upper limit of voltage rating V a_upper When, the upper limit of the voltage rating Va_upper Change to FF voltage rating command value V a_ff The calculated FF voltage rating command value V a_ff It is input to the voltage rating synthesis unit 40 and the voltage rating limiter 41.

[0080] (a-2) Flux Feedback Control Unit

[0081] As described above, the flux feedback control unit comprises a reference current calculation unit 35, a flux calculation unit 36, a flux estimation unit 37, a flux deviation calculation unit 38, and a PI control unit 39. Furthermore, the flux feedback control unit as a whole calculates the flux state quantity representing the flux generated in the motor 9 based on the current supplied to the motor 9. The flux generated in the motor 9 is the flux of the permanent magnet (hereinafter referred to as the magnet flux) Φ of the motor 9. a The resultant magnetic flux is the magnetic flux generated by the magnetic flux produced by the current supplied to the windings (coils) of the motor 9 (hereinafter referred to as winding magnetic flux). The magnetic flux state quantity is, for example, the reference magnetic flux quota φ representing the target response of the quota (hereinafter referred to as magnetic flux quota) that represents the vector of the resultant magnetic flux. 0_ref The estimated value of the magnetic flux rating is φ. 0_est And the magnetic flux deviation φ, which is their deviation. 0_err In addition, the flux feedback control unit calculates and feeds back the FF voltage rating command value V based on the flux state quantity. a_ff Feedback quota instruction value (FB voltage quota instruction value V) a_fb ).

[0082] Reference current calculation unit 35 uses the d-axis current target value i d * Calculate the d-axis reference current i, representing the target response of the d-axis current. d_ref *. Additionally, the reference current calculation unit 35 calculates the q-axis current target value i. q *Calculate the q-axis reference current i, representing the target response of the q-axis current. q_ref *. d-axis reference current i d_ref * and q-axis reference current i q_ref *The current is input to the flux calculation unit 36. Additionally, the reference current calculation unit 35, for example, has a connection to LPF22 (reference). Figure 2 Low-pass filters (LPFs) with the same time constant.

[0083] The flux processing unit 36 ​​is based on the d-axis reference current i d_ref * and q-axis reference current i q_ref *To calculate the reference magnetic flux quota φ 0_ref Reference magnetic flux quota φ 0_refThis represents the target value of the flux rating in voltage phase control. The flux calculation unit 36 ​​uses the inductance L of the d-axis according to the following equation (5). d Inductance L along the q-axis q Magnetic flux Φ a Calculate the reference magnetic flux quota φ 0_ref Reference magnetic flux quota φ 0_ref It is input to the flux deviation calculation unit 38.

[0084] (Equation 5):

[0085]

[0086] In addition, the magnetic flux Φ of the magnet a Inductance L along the d-axis d and the q-axis inductance L q It is a constant. The d-axis reference current i d_ref * and q-axis reference current i q_ref * is a variable. However, the magnetic flux Φ of the magnet... a Inductance L along the d-axis d and the q-axis inductance L q The constants are sometimes based on the magnet temperature of motor 9 and the d-axis current i. d q-axis current i q d-axis current target value i d * and / or the target value of the q-axis current i q *And change. Therefore, the flux calculation unit 36 ​​can appropriately change part or all of the constants according to the magnet temperature, etc. In this case, the flux calculation unit 36 ​​refers to a mapping diagram that determines the above constants according to the magnet temperature, etc., and uses appropriate constants corresponding to the magnet temperature, etc. This mapping diagram is predetermined through experiments or simulations, etc.

[0087] The flux estimation unit 37 is based on the d-axis current i as the detection value. d and q-axis current i q Estimated value of operational flux φ 0_est Estimated value of magnetic flux φ 0_est This is the estimated value of the actual magnetic flux rating in motor 9. Estimated magnetic flux rating φ 0_est The calculation method, besides using the d-axis current i d and q-axis current i q Apart from being a variable, it is related to the reference magnetic flux quota φ 0_ref The calculation method is the same. That is, the flux estimation unit 37 calculates the flux quota estimation value φ according to the following formula (6). 0_est Estimated value of magnetic flux φ 0_est It is input to the flux deviation calculation unit 38.

[0088] (Formula 6):

[0089]

[0090] Magnetic flux deviation calculation unit 38 calculates magnetic flux deviation φ 0_err In this embodiment, the flux deviation calculation unit 38 calculates the flux deviation from the reference flux rating φ. 0_ref Subtract the estimated value of magnetic flux φ 0_est To calculate the magnetic flux deviation φ 0_err Magnetic flux deviation φ 0_err It is input into the PI control unit 39.

[0091] The PI control unit 39 calculates the feedback voltage rating command value (hereinafter referred to as the FB voltage rating command value) V through PI control. a_fb FB voltage rating command value V a_fb It is used to feed back the FF voltage rating command value V a_ff The voltage rating command value. Specifically, the PI control unit 39 uses the electrical angular velocity ω according to the following formula (7). e and magnetic flux deviation φ 0_err To calculate the FB voltage rating command value V a_fb In equation (7), "Kφ" p "It's the proportional gain." Kφ i "This is the integral gain. These gains are determined in advance through experiments or simulations. Additionally, the electric angular velocity ω..." e It functions as a variable gain that varies according to the rotational speed N. FB voltage rating command value V a_fb It is input to the voltage rating synthesis unit 40.

[0092] (Equation 7):

[0093]

[0094] (a-3) Voltage Rating Synthesis Section

[0095] The voltage rating synthesis unit 40 synthesizes the FB voltage rating command value V by... a_fb Feedback to FF voltage rating command value V a_ff To generate the voltage rating command value V a * Voltage rating instruction value V a * indicates a continuous value. In this embodiment, the voltage rating synthesis unit 40 synthesizes the FB voltage rating command value V. a_fb With FF voltage rating command value V a_ff The voltage rating command value V is calculated by adding them together. a * Voltage rating instruction value V a*The target value of the voltage rating is corrected based on the flux state quantity (or the current quantity, which serves as the calculation source for the flux state quantity). Thus, the voltage rating command value for voltage phase control (voltage rating command value V) a *) Through the FB voltage rating instruction value V a_fb The feedback allows it to be adjusted. As a result, the voltage rating command value (voltage rating command value V) for voltage phase control... a *) is controlled as flux deviation φ 0_err Approaching zero.

[0096] In addition, as mentioned above, the magnetic flux deviation φ 0_err From the reference magnetic flux rating φ 0_ref Subtract the estimated value φ of the magnetic flux quota 0_est The value after that. Therefore, for example, when the rotational speed N drops rapidly from a high speed state (motor 9 rotating from medium speed to high speed) due to a high load such as emergency braking, the estimated value of the magnetic flux rating φ is... 0_est Relative to the reference magnetic flux rating φ 0_ref It increases sharply. Furthermore, the magnetic flux deviation φ 0_err When the value becomes negative, the FB voltage rating command value V a_fb It also becomes a negative value. In this case, the voltage rating command value V a *Less than the FF voltage rating command value V, which is the initial target value. a_ff The result is that the voltage rating command value V a *This value becomes close to the voltage rating of the power applied to the motor 9 in current vector control. Similarly, when performing current vector control, in cases where the voltage rating of the power applied to the motor 9 increases sharply due to rapid acceleration, the voltage rating command value V... a *This becomes a value close to the voltage rating of the power applied to the motor 9 in current vector control. That is, feedback control based on the aforementioned flux state quantity has the effect of reducing the gap between the voltage ratings of voltage phase control and current vector control. Therefore, through feedback control based on the aforementioned flux state quantity, the switching between voltage phase control and current vector control is substantially seamless.

[0097] (a-4) Voltage Rating Limitation Section

[0098] Voltage rating limit unit 41 sets the voltage rating command value V a *Limited to the specified lower limit and the upper limit of the voltage rating (V). a_upper The values ​​between (voltage rating limit processing). The lower limit value is, for example, zero. When the voltage rating command value V a *Restricted to a lower or upper limit value V a_maxWhen this occurs, the voltage rating limit unit 41 outputs a notification signal to the PI control unit 39. Upon receiving this notification signal, the PI control unit 39 initializes its built-in integrator to prevent integral saturation.

[0099] (b-1) Voltage phase command value generation unit

[0100] The voltage phase command value generation unit 42 generates a feedforward voltage phase command value (hereinafter referred to as the FF voltage phase command value) α based on the operating state of the motor 9 through feedforward control. ff FF voltage phase command value α ff This indicates the phase of the voltage to be supplied to motor 9. Additionally, the FF voltage phase command value α... ff The voltage phase is a basic target value determined based on the operating state of the motor 9. The voltage phase command value generation unit 42 includes a voltage phase table 42a, which is used to generate the FF voltage phase command value α. ff The reference table. Voltage phase table 42a stores the FF voltage phase command value α corresponding to each operating state (operating point) of motor 9. ff The lookup table. The FF voltage phase command value α is stored in voltage phase table 42a. ff For example, the voltage phase value measured under nominal conditions for each operating state of the motor 9 in experiments, etc. In this embodiment, the voltage phase table 42a stores the FF voltage rating instruction value V. a_ff Speed ​​N, target torque T*, and FF voltage phase command value α ff Therefore, when acquiring these parameters, the voltage phase command value generation unit 42 generates an FF voltage phase command value α corresponding to the combination of these parameters by referring to the voltage phase table 42a. ff The generated FF voltage phase command value α ff It is input into the phase synthesis unit 47.

[0101] (b-2) Torque Feedback Control Unit

[0102] As described above, the torque feedback control unit comprises a reference torque generation unit 43, a torque estimation unit 44, a torque deviation calculation unit 45, and a PI control unit 46. The torque feedback control unit as a whole calculates the feedback voltage phase command value (hereinafter referred to as the FB voltage phase command value) α. fb FB voltage phase command value α fb It is used to feed back the FF voltage phase command value α ff The voltage phase command value.

[0103] The reference torque generation unit 43 uses the target torque value T* to generate a reference torque T representing the target response of the torque in the motor 9.ref The reference torque generating unit 43, for example, has a torque generation unit similar to LPF22 (reference torque generator). Figure 2 A low-pass filter with the same time constant. The generated reference torque T ref It is input into the torque deviation calculation unit 45.

[0104] Torque estimation section 44 calculates the estimated torque value T est Estimated torque T est This is an estimated value of the torque of the electric motor 9 under a specific operating condition. The torque estimation unit 44 is equipped with a tool for estimating the estimated torque value T. est The torque table (not shown). The torque table stores the estimated torque value T for each operating state (operating point) of the motor 9. est A lookup table. In this embodiment, the torque table stores the d-axis current i. d and q-axis current i q Estimated torque T est Therefore, when acquiring these parameters, the torque estimation unit 44 refers to the torque table and calculates the estimated torque value T corresponding to the combination of these parameters. est Estimated torque T est It is input into the torque deviation calculation unit 45.

[0105] Torque Deviation Calculation Unit 45 calculates torque deviation T err Torque deviation T err Reference torque T ref With the estimated torque T est The deviation. In this embodiment, the torque deviation calculation unit 45 calculates the deviation from the reference torque T. ref Subtract the estimated torque T est To calculate the torque deviation T err Torque deviation T err It is input into the PI control unit 46.

[0106] PI control unit 46 uses torque deviation T err (=T ref -T est To calculate the FB voltage phase command value α fb Specifically, the PI control unit 46 calculates the FB voltage phase command value α according to the following formula (8). fb In equation (8), "Kα" p "Kα" is the proportional gain. Additionally, "Kα" i "This is the integral gain. These gains are predetermined through experiments or simulations, etc. FB voltage phase command value α" fb It is input into the phase synthesis unit 47.

[0107] (Equation 8):

[0108]

[0109] (b-3) Phase synthesis section

[0110] Phase synthesis unit 47 uses the FB voltage phase command value α fb Feedback to FF voltage phase command value α ff To generate the voltage phase command value α*. In this embodiment, the phase synthesis unit 47 generates the FB voltage phase command value α*. fb Phase command value α of FF voltage ff The values ​​are added together to generate the voltage phase command value α*. The voltage phase command value α* is based on the torque deviation T. err (or used to calculate torque deviation T) err The target value for the voltage phase after correction (current quantity). This correction is to reduce the torque deviation T. err Correction for convergence to zero. Thus, the voltage phase command value α* generated by the phase synthesis unit 47 is input to the phase limiting unit 48.

[0111] (b-4) Phase limiting section

[0112] The phase limiting unit 48 limits the voltage phase command value α* within a specified voltage phase range (voltage phase limiting processing). The specified voltage phase range is defined from a specified lower limit value relative to the voltage phase (hereinafter referred to as the voltage phase lower limit value) α. min Up to a specified upper limit value relative to the voltage phase (hereinafter referred to as the voltage phase upper limit value) α max The range. Regarding the lower limit of voltage phase α. min and the upper limit of voltage phase α max The settings will be described in detail later. When the voltage phase command value α* is limited by the voltage phase limiting process, the phase limiting unit 48 outputs a notification signal of this situation to the PI control unit 46. After receiving the notification signal, the PI control unit 46 initializes its built-in integrator to prevent integral saturation.

[0113] (c-1) Vector Transformation Unit

[0114] The vector transformation unit 49 converts the voltage rating command value V according to the following formula (9). a * and voltage phase command value α* are transformed into d-axis voltage command value V. dv * and q-axis voltage command value V qv *

[0115] (Equation 9):

[0116]

[0117] The stabilizing filter 50 uses the aforementioned d-axis voltage command value V. dv * and q-axis voltage command value V qv * Calculate the d-axis voltage command value V, which serves as the voltage command value for voltage phase control. dv_fin * and q-axis voltage command value V qv_fin Specifically, the stabilizing filter 50 calculates these d-axis voltage command values ​​V according to equation (10). dv_fin * and q-axis voltage command value V qv_fin *. This stabilizing filter 50 cancels the d-axis current i after vector transformation. d and q-axis current i q Relative to the d-axis voltage command value V dv * and q-axis voltage command value V qv The resonant characteristics of * are observed. Therefore, the stabilizing filter 50 stabilizes the feedback loop.

[0118] (Equation 10):

[0119]

[0120] In addition, “k” in equation (10) 11 “k” 12 “k” 21 "and "k 22 "It is based on the electric angular velocity ω" e And the variable gain that changes. These variable gains (k) 11 k 12 k 21 k 22 The value of L is determined by the following equation (11). In equation (11), "L" d ' is the dynamic inductance along the d-axis. Additionally, "L" q '" represents the dynamic inductance along the q-axis.

[0121] (Equation 11):

[0122]

[0123] From equation (10), it can be seen that in the stable filter 50, the d-axis current i d and q-axis current i q Designed to transitionally become the specified time constant τ m The voltage applied to motor 9 is phase-leading due to the inductances of the d-axis and q-axis, but this phase lead is small enough to be negligible from the perspective of the entire system. Therefore, if the phase lead caused by the inductances of the d-axis and q-axis is ignored, the voltage phase control d-axis voltage command value V... dv_fin * and q-axis voltage command value V qv_fin The transient dynamic characteristics of * can be regarded as the time constant τm A delayed response.

[0124] As described above, the voltage phase control unit 2 changes the voltage phase command value α* to reduce the torque deviation T. err The torque converges to zero. Therefore, in voltage phase control, even when the voltage rating of the power supplied to the motor 9 is saturated, the torque of the motor 9 can be changed as required. In particular, even in overmodulation or the rectangular wave state, which is its limit, the torque of the motor 9 can be appropriately controlled through voltage phase control. Furthermore, in the above-described voltage phase control, the feedback flux deviation φ... 0_err To change the voltage rating instruction value V a Therefore, the switching between voltage phase control and current vector control is seamless.

[0125] Furthermore, as described above, the voltage phase control unit 2 uses rotational parameters (electric angular velocity ω) related to the rotational speed N of the motor 9. e The final command value (d-axis voltage command value V) of the voltage applied to motor 9 via voltage phase control is calculated. dv_fin * and q-axis voltage command value V qv_fin *) and performs calculations using a pre-set "command value calculation model" (so-called transfer function). Then, the voltage phase control unit 2 acquires the final command value (d-axis voltage command value V) calculated according to this command value calculation model for voltage phase control. dv_fin * and q-axis voltage command value V qv_fin The required time T for *) s Then, based on the required time T... s Change the detected rotational speed parameter (electric angular velocity ω) e ), and according to the command value calculation model, using the modified rotational speed parameters (electric angular velocity |ω e The final command value (d-axis voltage command value V) is calculated using ′∣). dv_fin * and q-axis voltage command value V qv_fin *).

[0126] The required time T corresponding to this "instruction value operation model" s For example, it includes the detection rotational speed parameter (electric angular velocity ω). e From the start to the calculation of the final command value (d-axis voltage command value V) dv_fin * and q-axis voltage command value V qv_fin The time required up to *). Additionally, the required time T. s The timing of setting the command value calculation model (the timing of designing the voltage phase control unit 2) is determined. The command value calculation model is typically set to the required time T. sThe smaller the value, the better. However, regardless of the specific system in which the instruction-value arithmetic model is installed, the required time T will be significantly longer due to latency caused by various built-in checks and calculations. s It is not zero. Furthermore, in the required time T... s The required time T is when the time includes not only the delay time generated by the calculation of the voltage phase control unit 2, but also the delay time required to obtain the parameters required for voltage phase control (e.g., speed parameters). s This delay time can be included. For example, the time lag (detection period) in detecting rotational speed N can be included in the required time T. s In addition, based on the final command value (d-axis voltage command value V) dv_fin * and q-axis voltage command value V qv_fin *) If there is a delay time before the actual voltage is applied from the inverter 6 to the motor 9, this delay time can also be included in the required time T. s In other words, the required time T. s This represents part or all of the delay time in the response from the time the speed parameter related to speed N is detected until voltage is applied to motor 9. In this embodiment, the required time T s This is known by setting the instruction value operation model as described above. Therefore, the required time T... s Relevant information may be pre-stored in a memory not shown.

[0127] (Setting of upper and lower voltage phase limits)

[0128] Figure 4 It is a graph used to represent the setting of the voltage phase range in voltage phase control. For example... Figure 4 As shown, in a certain electric motor, the correlation between voltage phase α and torque T is maintained approximately within a range of -105 degrees to +105 degrees. At this point, the upper limit of voltage phase α... max Set to +105 degrees, and the lower limit of voltage phase α min It is set to -105 degrees. Therefore, in the case of having Figure 4 When a motor with the characteristics of a certain type is used as motor 9 in motor system 100, the phase limiting unit 48 limits the voltage phase command value α* to a range of -105 degrees to +105 degrees. This is to ensure the controllability of motor 9 by maintaining its correlation with the torque of motor 9.

[0129] (Structure of the phase change unit and method of phase change)

[0130] Figure 5 This is a block diagram showing the structure of the phase-changing unit 32. For example... Figure 5As shown, the phase change unit 32 includes: an acceleration calculation unit 51, a change restriction unit 52, a phase change amount calculation unit 53, an addition unit 54, and a final restriction unit 55.

[0131] Acceleration calculation unit 51 calculates the electric angular velocity ω in relation to time. e The absolute value of |ω e | Perform differentiation to calculate the electric angular acceleration A e In this embodiment, the acceleration calculation unit 51 is a so-called incomplete differentiator, which combines the differentiator [s] and the low-pass filter "1 / (τ)". w The acceleration calculation unit 51 approximates the electric angular velocity ω by combining "s+1". e The absolute value of |ω e | Perform time differentiation. Time constant "τ" w "This is a predetermined constant that takes into account the tolerance to high-frequency noise contained in the detected value of rotational speed N and the responsiveness to changes in rotational speed N. Electrical angular acceleration A" e It was entered into the change restriction section 52.

[0132] The modification limit unit 52 is based on electric angular acceleration A e Toggle whether to change the electric angular velocity ω e The phase switch. In this embodiment, the changing limiting unit 52 switches the electric angular acceleration A. e With a predetermined threshold A e0 A comparison is made to determine whether the electric angular velocity ω needs to be changed. e The phase. Specifically, in the electric angular acceleration A e Less than threshold A e0 In this case, the modification restriction unit 52 decides to implement the change relative to the electric angular velocity ω. e The phase change (hereinafter referred to as phase change). On the other hand, in the electric angular acceleration A e Threshold A e0 Under the above circumstances, the modification restriction unit 52 decides not to implement the change restriction on the electric angular velocity ω. e Phase change. Threshold A e0 Based on pre-determined parameters such as experiments or simulations. Additionally, the threshold A... e0 Arbitrarily determined to correspond to a specific scenario.

[0133] In addition, when determined to be electric angular acceleration A e Less than threshold A e0 In the case of changing the input electrical angular acceleration A of the limiting unit 52, the output of the limiting unit 52 is changed. e On the other hand, when determined to be electric angular acceleration A... e Threshold A e0In the above cases, the change restriction unit 52 outputs a predetermined initial value (zero in this embodiment). The output of the change restriction unit 52 is input to the phase change amount calculation unit 53.

[0134] The phase change calculation unit 53 uses the output of the change restriction unit 52 to calculate the electric angular velocity ω. e The amount of phase change (hereinafter referred to as phase change) ω ecmp In addition, the phase change calculation unit 53 calculates the phase change amount ω. ecmp At that time, the final command value (d-axis voltage command value V) is calculated from the command value calculation model based on the voltage phase control. dv_fin * and q-axis voltage command value V qv_fin The required time T up to this point *) s Then, the phase change calculation unit 53 considers the required time T. s To calculate the phase change ω ecmp The calculated phase change ω ecmp It was input into the addition section 54.

[0135] In this embodiment, the phase change calculation unit 53 multiplies the output of the change restriction unit 52 by the required time T. s To calculate the phase change ω ecmp Therefore, at electric angular acceleration A e Less than threshold A e0 In this case, the phase change amount ω ecmp It is electric angular acceleration A e With the required time T s The product (A) e T s Therefore, the phase change calculation unit 53 calculates the phase change amount at the required time T. s The electric angular velocity ω of the quantity that changes during the period e Equivalent phase change ω ecmp However, at electric angular acceleration A e Threshold A e0 In the above case, the output of the change restriction unit 52 is zero, therefore the phase change amount ω ecmp It is also zero. This means that the electric angular velocity ω remains unchanged. e The scene of phase.

[0136] Furthermore, in this embodiment, as described above, the rotational speed calculator 11 calculates the rotational speed per unit time Δt. Nave The electric angular velocity ω is calculated from the change in electric angle θ. e Therefore, at a certain electric angular acceleration A e The wasted time required to detect the rotational speed N can be roughly considered as Δt. NaveApproximately 2 / 3. Additionally, as mentioned above, in the stabilizing filter 50, the d-axis voltage command value V... dv_fin * and q-axis voltage command value V qv_fin *For the d-axis voltage command value V dv * and q-axis voltage command value V qv The response of * can be considered as a time constant τ m The response delay is one step. Therefore, at a certain electric angular acceleration A... e The wasted time in outputting voltage to motor 9 can be considered as a time constant τ. m Approximately. Therefore, in this embodiment, the required time T s It is represented by their sum. That is, the required time T. s Calculate according to the following formula (12).

[0137] (Equation 12):

[0138]

[0139] By setting the required time T in this way s At electric angular acceleration A e This can be considered as a roughly certain time range, within each required time T. s Electric angular velocity ω e Within the range of possible changes, the electric angular velocity ω is changed. e The phase. As a result, even when using the phase-changed electric angular velocity |ω e Using the voltage rating can also prevent exceeding the required time T. s Excessive changes.

[0140] Addition part 54 will change the phase amount ω ecmp With electric angular velocity ω e Add them together. Therefore, the electric angular velocity ω e The phase is ahead. The output of the adder 54 is the phase-adjusted electric angular velocity |ω. e However, the electric angular velocity |ω after the phase change e Output via the final limiting section 55.

[0141] The final limiting unit 55 is the phase-modulated electric angular velocity |ω, which is the output of the adding unit 54. e The maximum function (max) of the independent variable is composed of '∣ and the fixed value "zero (0)". Therefore, the lower limit value is limited by the final limiting part 55 to make the electric angular velocity ∣ω after phase change... e ′∣ does not become a negative value.

[0142] As described above, the phase change unit 32 acquires the command value obtained through voltage phase control and calculates the final command value (d-axis voltage command value V).dv_fin * and q-axis voltage command value V qv_fin The required time T up to this point *) s Furthermore, the phase change unit 32 is based on the required time T. s Changing the electric angular velocity ω e The phase. Then, based on the electric angular velocity |ω| with the phase changed. e The process involves calculating the final command value of the command value calculation model based on voltage phase control. This phase change process pre-changes the electric angular velocity ω. e The phase, so that the electric angular velocity |ω after phase change e ′ | Approximately the time T required to pass s The electric angular velocity ω after e .

[0143] (The specific structure of the output controller and the generation of control mode signals)

[0144] Figure 6 This is a block diagram showing the structure of the control mode switching determination unit 13. For example... Figure 6 As shown, the control mode switching determination unit 13 includes: a first quota threshold calculation unit 94, a second quota threshold calculation unit 95, an average filter 96, an average filter 97, a quota calculation unit 98, and a control mode determination unit 99.

[0145] The first quota threshold calculation unit 94 is based on the first modulation factor threshold M th1 Calculate the first quota threshold V a_th1 First modulation factor threshold M th1 This is a threshold value determined for the modulation factor M in PWM control, representing the modulation factor M that serves as the reference for switching the control mode from voltage phase control to current vector control. First rated threshold V a_th1 This is the same as the average voltage rating command value V described later. a_fin_flt The threshold value used for comparison is employed as the switching condition from voltage phase control to current vector control. The first rated threshold V... a_th1 According to the first formula of the following equation (13), the DC voltage V of the storage battery 15 is used. dc To calculate.

[0146] The second quota threshold calculation unit 95 is based on the second modulation factor threshold M th2 Calculate the second quota threshold V a_th2 The second modulation factor threshold M th2 This is a threshold value determined for the modulation factor M in PWM control, representing the modulation factor M that serves as the reference for switching the control mode from current vector control to voltage phase control. The second rated threshold V... a_th2 This is the same as the average voltage rating command value V described later. a_fin_fltThe threshold value used for comparison is employed as the switching condition from current vector control to voltage phase control. The second rated threshold V a_th2 According to the second formula of equation (13), the DC voltage V of battery 15 is used. dc To calculate.

[0147] (Equation 13):

[0148]

[0149] Furthermore, in this embodiment, the upper limit value M of the modulation factor M is... max * and the first modulation factor threshold M th1 and the second modulation factor threshold M th2 The magnitude relationship is shown in equation (14) below. That is, the first modulation factor threshold M related to the switching from voltage phase control to current vector control. th1 It is the smallest among them. Furthermore, the second modulation factor threshold M associated with the switching from current vector control to voltage phase control... th2 It is the upper limit value M max * and the first modulation factor threshold M th1 The value between [a certain value]. That is, in this embodiment, the first modulation factor threshold M [is a certain value]. th1 Second modulation factor threshold M th2 These are at least mutually distinct values. Therefore, the first modulation factor threshold M is used. th1 The calculated first quota threshold V a_th1 and using the second modulation factor threshold M th2 The calculated second quota threshold V a_th2 These are also different values. As a result, hysteresis is present in the switching between current vector control and voltage phase control. In this embodiment, since the switching between current vector control and voltage phase control is performed seamlessly, by setting hysteresis for these switching, the occurrence of repeated switching (so-called oscillation) can be suppressed.

[0150] (Equation 14):

[0151] M max * >M th2 >M th1 (14)

[0152] In addition, the upper limit value M of the modulation factor M max * First modulation factor threshold M th1 and the second modulation factor threshold M th2 For example, the following setting applies: That is, the upper limit value M. max * indicates the value of the modulation factor M in the rectangular wave state is "1.1". The second modulation factor threshold M th2The value of the modulation factor M, which marks the boundary between the non-overmodulation and overmodulation states, is 1.0. The first modulation factor threshold M... th1 The value of the modulation factor M, "0.9", is considered to reliably be in a non-overmodulation state.

[0153] The average filter 96 passes the final voltage command value V on the d-axis. d_fin * Implement averaging to reduce the final d-axis voltage command value V. d_fin * Noise. The averaging filter 96 is, for example, a low-pass filter (LPF). The output of the averaging filter 96 is the averaged d-axis final voltage command value V. d_fin_flt *. The average d-axis final voltage command value V. d_fin_flt *This data was input into the quota calculation department 98.

[0154] The average filter 97 passes the final voltage command value V on the q-axis. q_fin *Averaging is performed to reduce the final q-axis voltage command value V. q_fin * Noise. The averaging filter 97 is, for example, a low-pass filter (LPF). The output of the averaging filter 97 is the averaged q-axis final voltage command value V. q_fin_flt *. The average q-axis final voltage command value V. q_fin_flt *This data was input into the quota calculation department 98.

[0155] The quota calculation unit 98 uses the average d-axis final voltage command value V according to the following formula (15). d_fin_flt * and the average q-axis final voltage command value V q_fin_flt * Calculate the average voltage rating command value V a_fin_flt *. Specifically, the quota calculation unit 98 calculates the average voltage quota command value V according to the following formula (15). a_fin_flt * Average voltage rating command value V a_fin_flt * is input to the control mode determination unit 99.

[0156] (Equation 15):

[0157]

[0158] Additionally, the output controller 3 sometimes outputs a d-axis voltage command value V for voltage phase control. d_fin * and q-axis voltage command value V qv_fin *As the final voltage command value V for the d-axis d_fin * and q-axis final voltage command value V q_fin * In this case, the average voltage rating command value V can also be used instead of the aforementioned value. a_fin_flt * The final voltage rating command value V input to the vector conversion unit 49 a_fin *Input to control mode determination unit 99.

[0159] Control mode determination unit 99 uses the first quota threshold V a_th1 Second quota threshold V a_th2 and the average voltage rating command value V a_fin_flt * The appropriate control mode is determined based on the operating state of the motor 9. The determination result of the control mode determination unit 99 is output as a control mode signal Sm to the current vector control unit 1, the voltage phase control unit 2, and the output controller 3.

[0160] Figure 7 This is an explanatory diagram illustrating the method for determining the control mode of the control mode determination unit 99. (For example...) Figure 7 As shown, the control mode determination unit 99 determines the average voltage rating command value V. a_fin_flt * and the first fixed threshold V a_th1 and the second quota threshold V a_th2 A comparison is made. If the result of this comparison is that the average voltage rating command value V is detected when controlling motor 9 via voltage phase control... a_fin_flt * represents the first fixed threshold V a_th1 In the following cases, based on the detection result, a switch to current vector control is determined. Then, a control mode signal Sm indicating this (e.g., a control mode switching command) is output. Additionally, when controlling the motor 9 via voltage phase control, the average voltage rating command value V is detected. a_fin_flt * represents the second quota threshold V a_th2 In the above cases, based on the detection result, it is decided to switch to voltage phase control. Then, a control mode signal Sm indicating this decision is output.

[0161] (Specific structure of the output controller)

[0162] Figure 8 This is a block diagram representing the structure of output controller 3. For example... Figure 8 The diagram shows a switch that toggles between current vector control and voltage phase control based on the control mode signal Sm. When the control mode is set to current vector control based on the control mode signal Sm, the output controller 3 outputs the d-axis voltage command value V for current vector control. di_fin *As the final voltage command value V for the d-axis d_fin *Output. Additionally, at the same time, the output controller 3 will output the q-axis voltage command value V of the current vector control. qi_fin *As the final voltage command value V for the q-axis q_fin *Output. On the other hand, when the control mode is set to voltage phase control based on the control mode signal Sm, the output controller 3 outputs the d-axis voltage command value V for voltage phase control. dv_fin *As the final voltage command value V for the d-axis d_fin*Output. Additionally, at the same time, the output controller 3 will output the q-axis voltage command value V for voltage phase control. qv_fin *As the final voltage command value V for the q-axis q_fin * Output.

[0163] (The function of this implementation method)

[0164] The operation of the electric motor system 100 and the electric motor 9 configured as described above in this embodiment will be explained below.

[0165] Figure 9 This is a flowchart of the motor control in this embodiment. For example... Figure 9 As shown, firstly, in step S101, the three-phase AC current of the motor 9 is detected by the current detector 8, and the detected three-phase AC current is transformed into the d-axis current i by the coordinate transformation processing of the converter 12. d and q-axis current i q Additionally, in step S102, the electrical angle θ of the motor 9 is detected by the rotor detector 10, and the rotational speed N is calculated based on the detected electrical angle θ by the rotational speed calculator 11. Furthermore, in step S103, the target torque value T* is obtained, and the DC voltage V of the battery 15 is also obtained. dc That is, to acquire or calculate the various parameters required for the control of motor 9.

[0166] After obtaining the various parameters as described above, in step S104, the control mode switching determination unit 13 performs a control mode switching determination. In step S105, if the control mode switching determination result indicates that the motor 9 is controlled by current vector control, the steps after step S106 are executed. In step S106, the target value i of the d-axis current is calculated by the current vector control unit 1. d * and the target value of the q-axis current i q * and non-interference voltage V d_dcpl * Then, in step S107, the target value i of the d-axis current is fed back respectively. d * and the target value of the q-axis current i q The current feedback processing calculates the d-axis current feedback voltage command value V. di Current feedback voltage command value V for the ' and q axes qi Furthermore, in step S108, the non-interference voltage V processed by LPF22 is... d_dcpl_flt With current feedback voltage command value V di Non-interference control of summation, d-axis voltage command value V in operational current vector control di_fin Similarly, in step S108, the q-axis voltage command value V in the operational current vector control is... qi_fin *

[0167] This is how the d-axis voltage command value V in current vector control is calculated. di_fin * and q-axis voltage command value V qi_fin Finally, after the output control processing of the output controller 3 in step S109, the three-phase voltage command value is calculated by the converter 4 in step S110. Then, the pulse width modulation signal generator 5 generates a PWM signal based on the three-phase voltage command value to execute the control of the motor 9 based on pulse width modulation.

[0168] On the other hand, if the result of the control mode switching determination in step S104 is that the operating state of the motor 9 in step S105 is not suitable for current vector control, then voltage phase control is performed in step S111.

[0169] Figure 10 This is a flowchart of voltage phase control. For example... Figure 10 As shown, in voltage phase control, the electric angular velocity ω is executed in step S201. e Phase change processing. Additionally, in step S202, the target d-axis current value i is obtained from the current vector control unit 1. d * and the target value of the q-axis current i q * In step S203, the reference magnetic flux rating φ is calculated. 0_ref and reference torque T ref .

[0170] Then, in step S204, the electric angular velocity |ω| after phase change processing is calculated. e ′∣ and reference magnetic flux quota φ 0_ref To calculate the induced voltage V a0 Then, in step S205, the upper limit value V of the voltage rating is calculated. a_upper FF voltage rating command value V a_ff and FF voltage phase command value α ff In step S206, the target value of the d-axis current i is used. d * and the target value of the q-axis current i q *To calculate the estimated value of magnetic flux quota φ 0_est and the estimated torque T est Then, in step S207, the FB voltage rating command value V is calculated. a_fb .

[0171] Next, by changing the FF voltage rating command value V a_ff and FB voltage rating instruction value V a_fb The voltage rating command value V is calculated by adding them together. a * In step S208, the voltage rating command value V calculated as described above... a*Restricted to a range between the specified lower limit and the voltage rating upper limit V. a_upper The values ​​between.

[0172] In step S209, when the voltage rating instruction value V is in the voltage rating limit processing... a When restricted, step S210 is executed, and the PI control unit 39 is initialized. On the other hand, in step S209, the voltage rating command value V in the aforementioned voltage rating restriction process... a *If no restrictions are imposed, step S210 is omitted. As a result, the voltage rating command value V after voltage rating restriction processing is input to the vector transformation unit 49. a *

[0173] On the other hand, in step S211, the FB voltage phase command value α is calculated. fb Next, by changing the FF voltage phase command value α... ff and FB voltage phase command value α fb The voltage phase command value α* is calculated by summing the values. In step S212, voltage phase limiting processing is performed on the voltage phase command value α* calculated as described above. In step S213, if the voltage phase command value α* is limited by the voltage phase limiting processing, the PI control unit 46 is initialized in step S214. On the other hand, if the voltage phase command value α* is not limited by the voltage phase limiting processing in step S213, step S214 is omitted. As a result, the voltage phase command value α* after phase limiting processing is input to the vector transformation unit 49.

[0174] In step S215, the vector transformation unit 49 converts the voltage rating command value V a * and voltage phase command value α* are transformed into d-axis voltage command value V. dv * and q-axis voltage command value V qv *. Then, the d-axis voltage command value V. dv * and q-axis voltage command value V qv *The output is after stabilization and filtering in step S216. The subsequent process is the same as current vector control, such as... Figure 9 As shown, after the output control processing of the output controller 3 in step S109, the converter 4 calculates the three-phase voltage command value in step S110. Then, the pulse width modulation signal generator 5 generates a PWM signal based on the three-phase voltage command value to execute the control of the motor 9 based on pulse width modulation.

[0175] As described above, in the voltage phase control of this embodiment, the motor 9 is sometimes controlled in an overmodulation state depending on the operating state. Furthermore, when the rotational speed N is detected, the rotational speed N is converted into an electrical angular velocity ω. eFurthermore, the electric angular velocity ω is used in the calculation of the command value for voltage phase control. e However, it is not a direct use of the electrical angular velocity ω, which is equivalent to the detected rotational speed N. e Instead, it is the electric angular velocity ω e The execution took into account the required time T. s Phase change processing is performed. Therefore, in the voltage phase control of this embodiment, the electric angular velocity |ω| after phase change processing is used. e The calculation of the final command value according to the command value calculation model of voltage phase control is performed. As a result, in the voltage phase control of this embodiment, the motor 9 can be appropriately controlled regardless of the operating conditions. That is, according to the voltage phase control of this embodiment, as shown below, neither excessive nor insufficient voltage is generated in the voltage applied to the motor 9, and the overcurrent that is worrying in the scenario where the speed N of the motor 9 changes suddenly when controlled in an overmodulation state can be appropriately prevented.

[0176] Figure 11 It represents (A) electric angular velocity ω e (B) Electric angular acceleration A e (C) The current Im flowing through motor 9, (D) The voltage Vm applied to motor 9. Figure 11 These represent the parameters of motor 9 under overmodulation control via voltage phase control throughout the entire period from time t0 to time t5. Furthermore, during the period from time t0 to time t1, motor 9 operates at a constant speed N, which decreases abruptly from time t1. Additionally, the current Im flowing through motor 9 is, for example, the d-axis current i. d q-axis current i q Or the d-axis current i d With q-axis current i q The mean square of the voltage. Additionally, the voltage Vm applied to motor 9 is the same as the d-axis voltage command value V. dv_fin * and q-axis voltage command value V qv_fin *Corresponding voltage rating.

[0177] like Figure 11 As shown in (A), the electric angular velocity ω is obtained by transforming the detected rotational speed N. e The detected electric angular velocity deviates from the actual angular velocity (hereinafter referred to as the actual angular velocity) 201 of the motor 9 after the sudden decrease in rotational speed N at moment t1. This is because, due to the sudden decrease in rotational speed N of the motor 9, the required time T... s Even the slight response delay on the left and right sides has a significant impact on the control of motor 9.

[0178] like Figure 11As shown by the dotted line in (B), due to the sudden decrease in rotational speed N from time t1, the actual electrical angular acceleration (hereinafter referred to as actual angular acceleration) 202 of the motor 9 decreases stepwise at time t1. At this time, as... Figure 11 (B) shows the solid line indicating the electric angular velocity ω. e The electric angular acceleration A obtained by differentiation e (Detecting electric angular velocity) Due to the required time T s And follow the delay. Therefore, the electric angular acceleration A e At approximately time t3, it is roughly consistent with the actual angular acceleration 202.

[0179] Therefore, in the voltage phase control of this embodiment, the required time T is taken into account. s To change the electric angular velocity ω e The phase. The electric angular velocity ω e The phase change is the detected electric angular acceleration A e With threshold A e0 Comparison, at electric angular acceleration A e Less than threshold A e0 It was carried out after time t2. The result was as follows: Figure 11 As shown in (A), the electric angular velocity |ω| after phase change e | relative to the detected electric angular velocity ω e Decrease starting from time t2. Additionally, as... Figure 11 As shown in (A), the electric angular velocity |ω| after phase change e '|From the detected electric angular velocity ω e The phase change exceeds the actual electric angular velocity by 201 and is further reduced. This is because the phase change is predicted to occur within the required time T. s And so it is performed. That is, the phase change performed in the voltage phase control of this embodiment is not to change the detected electric angular velocity ω. e Instead of a correction or compensation consistent with the actual electric angular velocity 201, it is a change that further leads the phase compared to the actual electric angular velocity 201. For example... Figure 11 As shown in (A), in this embodiment, the phase-changed electric angular velocity |ω e '| Relative to the actual electric angular velocity 201, it is roughly ahead of the phase from time t3 to time t4.

[0180] If the electric angular velocity ω is changed as described above e The phase, and the electric angular velocity |ω after phase change. e '| The command value calculation used for voltage phase control then suppresses the current Im flowing through motor 9 to the upper limit of the current that can flow through motor 9 (hereinafter referred to as the upper limit of current I) Lim The following. Specifically, such as Figure 11As shown in curve GI1 of (C), the detected electric angular velocity ω is used directly without phase change. e When calculating the command value for voltage phase control, even with electrical angular acceleration A... e After stabilizing at an actual angular acceleration of 202 at time t3, the current flowing through motor 9 continues to rise. As a result, the current flowing through motor 9 exceeds the upper current limit I. Lim Overcurrent. On the other hand, such as Figure 11 As shown in curve GI2 of (C), when using the phase-changed electric angular velocity ω e When calculating the final command value of the command value calculation model based on voltage phase control, after time t3, the rise in current flowing through motor 9 is suppressed, becoming a roughly flat transition. Therefore, the current flowing through motor 9 will not exceed the upper current limit I. Lim Additionally, the upper limit of current I Lim The durability of the electric motor 9 is predetermined.

[0181] In addition, such as Figure 11 As shown in curve GV1 of (D), without phase change, the detected electric angular velocity ω is used directly. e When calculating the final command value based on the command value calculated according to the voltage phase control, although the speed N decreases sharply, the voltage Vm applied to the motor 9 decreases slowly. This is one of the reasons why the current flowing through the motor 9 continues to rise as described above (refer to curve GI1). On the other hand, as... Figure 11 As shown in curve GV2 of (C), if the phase-changed electric angular velocity ω is used... e When the command value for voltage phase control is calculated, the voltage Vm applied to the motor 9 decreases more rapidly than curve GV1. This suppresses the rise in current flowing through the motor 9 (refer to curve GI2).

[0182] Furthermore, phase change processing is included in voltage phase control. That is, instead of applying a change to the result of calculating the command value for voltage phase control, voltage phase control appropriately adjusts the voltage applied to motor 9 while in a state including phase change processing. Therefore, in Figure 11 The text explains the shifts in various parameters when the speed N decreases sharply. However, when the speed N changes slowly, the motor 9 can be appropriately controlled through voltage phase control to prevent over- or under-voltage issues.

[0183] Furthermore, the electric angular velocity ω performed in this embodiment e The phase change causes the phase to lead (shift forward) compared to the actual electric angular velocity 201. However, to prevent the drawbacks caused by excessive phase lead, the phase should not exceed the required time T. s Electric angular velocity ω eWithin the range of possible changes, the electric angular velocity ω e The phase is ahead. That is, the electric angular velocity ω e The amount of phase change is set within the range of the delay time from the detection of the starting speed N until voltage is applied to the motor 9. For example, in the required time T s In an ideal system with zero voltage, if the voltage to be applied to the motor 9 could be output without delay, overcurrent could be suppressed, but this is impossible. On the other hand, if excessive phase changes are performed beyond the system's inherent delay time, voltage over- or under-voltage occurs, increasing the risk of overcurrent. Therefore, as described above, it is preferable to perform phase change processing only within the system's inherent delay time.

[0184] Furthermore, in the above embodiment, the electric angular velocity ω is used in the calculation of the command value for voltage phase control. e However, it is also possible to avoid converting it to electric angular velocity ω. e The command value of the rotational speed N is set for calculation. In this case, similar to the above embodiment, the rotational speed N is subjected to phase change processing. That is, the electric angular velocity ω e The phase change is an example of a change in rotational speed N. Similarly, the phase change processing described above can be applied to rotational speed N or electrical angular velocity ω. e Other than the rotational speed parameters. That is, instead of the rotational speed N or electrical angular velocity ω. e Phase change processing can also be applied to rotational speed N or electrical angular velocity ω. e The relevant rotational speed parameters undergo phase-change processing. For example, the electric angular velocity ω before phase change... e Calculate the induced voltage V a0 At the same time, the induced voltage V can also be used. a0 Implement phase change processing.

[0185] In the above embodiment, the wasted time associated with the detection of rotational speed N and the time constant τ of the stabilizing filter 50 are used. m To estimate the required time T s (Refer to equation (12)), but this is the required time T. s One example is that multiple delay factors that can be considered in the design can be selected and added to the required time T. s In addition to the above, the required time T can be set using some or all of the sampling period of the electrical angle θ, the calculation period of the rotational speed N, the wasted time generated in pulse width modulation, the wasted time related to the output of the PWM pulse, and the response delay contained in the phase change unit 32 itself. s .

[0186] Furthermore, all the constants in the above embodiments can be changed into variables. For example, the constants in the above embodiments can be made variable based on various parameters related to the operating state of the motor 9 or inverter 6, such as current, speed N, torque, voltage, or temperature. In cases with high risks, such as hardware failures caused by overcurrent, the constants can be made variable to increase the correction amount for phase changes in the above embodiments.

[0187] Furthermore, in the above embodiment, the electric angular acceleration A is changed in the limiting unit 52. e With threshold A e0 Compare and determine whether to change the electric angular velocity ω. e Phase (reference) Figure 5 In this determination, if the threshold A is... e0 Setting it to zero means that phase change processing is not actually performed when the speed N increases, but only when the speed N decreases. The risk of overcurrent is greater when the speed N decreases than when the speed N increases. Therefore, if the threshold A is set to zero... e0 Setting it to zero ensures that phase-change processing is accurately implemented only in scenarios with a high risk of overcurrent, thus effectively reducing the risk of overcurrent. Additionally, if the threshold A is set to zero... e0 Setting it to zero maintains the original voltage phase control without phase change processing in scenarios where the speed N increases. Therefore, the original responsiveness of the voltage phase control is maintained in scenarios where the speed N increases. As a result, it prevents the deterioration of the motor 9's control efficiency due to phase change processing caused by extremely temporary voltage spikes. This is the change in phase change processing (phase change amount ω) when the absolute value of the speed N decreases. ecmp The change amount (phase change amount ω) in phase change processing when the absolute value of the rotational speed N increases is greater than the change amount of the rotational speed N. ecmp This is an example of a situation.

[0188] In addition, if the threshold A is... e0 If the threshold A is set to a predetermined negative value based on the characteristics of motor 9, then phase change processing is essentially not performed during gradual acceleration and deceleration. Furthermore, phase change processing is only appropriately performed during rapid acceleration and deceleration when the risk of overcurrent is high. Therefore, if the threshold A is set to a predetermined negative value, then phase change processing is not performed during gradual acceleration and deceleration. e0 By setting the specified negative value, overcurrent is effectively prevented only during rapid acceleration and deceleration, such as when the wheels of the vehicle equipped with the electric motor system 100 slip, when the wheels regain grip on the road surface after slipping, or when the wheels lock up. Furthermore, during gentle acceleration and deceleration as envisioned in normal driver operation, the original responsiveness of the voltage phase control, without phase-change processing, is maintained. Therefore, it is possible to prevent the deterioration of the control efficiency of the electric motor 9 due to phase-change processing caused by extremely temporary voltage excess.

[0189] In the above embodiment, the electric angular acceleration A is changed in the limiting unit 52. e With threshold A e0 Compare and determine whether to change the electric angular velocity ω. e The phase can be changed, but the change restriction section 52 can also be omitted. Figure 12 This is a block diagram showing the structure of the phase-changing unit 32 in this modified example. For example... Figure 12 As shown, in this phase change unit 32, instead of omitting the change restriction unit 52, the phase change amount calculation unit 53 calculates the phase change amount based on the electric angular acceleration A. e Variable. Specifically, the phase change calculation unit 53 in this modified example, for example, calculates the required time T. s and electric angular acceleration A e The product is further multiplied by the electric angular acceleration A. e The corresponding coefficient γ (not shown) is used to calculate the phase change ω. ecmp If this coefficient γ is applied to the electric angular acceleration A... e When the value is positive, it is set to "0", and the electric angular acceleration A e If the value is negative, it is set to "1", which is the same as setting the threshold A in the above implementation. e0 It functions the same way when set to zero. Additionally, if the coefficient γ is set to zero in the electric angular acceleration A... e If the value is greater than the specified negative value, it is set to "0"; in the case of electric angular acceleration A... e If the value is below a negative predetermined value, it is set to "1", which is consistent with the threshold A in the above implementation. e0 The function works the same when the specified value is set to a negative value.

[0190] Furthermore, as described above, by omitting the change restriction unit 52, the phase change amount calculation unit 53 calculates the phase change amount based on the electric angular acceleration A. e In variable situations, the motor 9 can be controlled more gently and appropriately.

[0191] For example, "electric angular acceleration A" can be set. e The smaller the value of the coefficient γ, the larger the value, so that the coefficient γ when the speed N increases is smaller than the coefficient γ when the speed N decreases. In this case, the phase change ω during deceleration ecmp Phase change ω during acceleration ecmp Large. Therefore, it is easy to appropriately balance overcurrent prevention and voltage phase control responsiveness according to the operating state of motor 9. This is the change amount (phase change amount ω) in the phase change processing when the absolute value of speed N decreases. ecmp The change amount (phase change amount ω) in phase change processing when the absolute value of the rotational speed N increases is greater than the change amount of the rotational speed N. ecmp This is an example of a situation.

[0192] Additionally, for example, "electric angular acceleration A" can be set. e The smaller the absolute value of γ, the smaller the value of the coefficient γ. In this case, at electric angular acceleration A e When the absolute value of the voltage phase control is small, it maintains its original responsiveness during gradual acceleration and deceleration, at electrical angular acceleration A. e To prevent overcurrent during rapid acceleration and deceleration when the absolute value is large.

[0193] As described above, the control method for the motor 9 in this embodiment and / or its variations is based on a voltage rating command value V, which represents the magnitude of the voltage to be supplied to the motor 9. a The control method for motor 9 uses voltage phase control, represented by a voltage phase command value α*, to control motor 9. In this control method, the required time T for calculation according to the command value calculation model is obtained. s The instruction value calculation model is used to calculate the speed parameter (electric angular velocity ω) related to the speed N of the motor 9. e The voltage (voltage rating command value V) applied to motor 9 via voltage phase control is calculated. a The final command value (d-axis voltage command value V) dv_fin * and q-axis voltage command value V qv_fin *). Then, based on the required time T s Change the detected rotational speed parameter (electric angular velocity ω) e Then, according to the command value calculation model, the modified rotational speed parameters (electric angular velocity ω) are used. e The final command value (d-axis voltage command value V) is calculated. dv_fin * and q-axis voltage command value V qv_fin *).

[0194] Therefore, the control method for the motor 9 in this embodiment and / or its variations can appropriately control the motor 9 when controlling it in an overmodulation state via voltage phase control. That is, it prevents overcurrent when the speed N of the motor 9 decreases suddenly. Furthermore, the change in the speed parameter does not change the command value calculation model or the final command value calculated according to the command value calculation model. That is, the command value calculation model includes the change in the speed parameter, and is set to also include the change in the speed parameter to calculate an appropriate final command value. Therefore, when the speed N of the motor 9 increases or decreases slowly, the voltage applied to the motor 9 will not be excessive or insufficient.

[0195] Furthermore, in the control method of the electric motor 9 in this embodiment and / or its variations, specifically, the rotational speed N is detected, and the electrical angular velocity ω is calculated based on the rotational speed N. e This allows for the detection of rotational speed parameters. Then, based on the required time T... s Change the electric angular velocity ωe The phase. Then, based on the phase-changed electric angular velocity |ω e The calculation model of ′∣ and command value is used to calculate the final command value (d-axis voltage command value V). dv_fin * and q-axis voltage command value V qv_fin *).

[0196] Thus, the electrical angular velocity ω is detected as a rotational speed parameter. e And will change its phase of electric angular velocity |ω e When used to calculate the final command value of the calculation model according to the command value, the motor 9 can be controlled particularly appropriately. This is because, among multiple speed parameters that can be considered, the electric angular velocity ω can be changed. e When considering the phase, other composite factors can be disregarded, which directly contributes to the prevention of overcurrent.

[0197] Furthermore, the control method of the electric motor 9 in this embodiment and / or its variations specifically involves changing the electric angular velocity ω. e The phase, so that the electric angular velocity |ω after phase change e ′ | Approximately the time T required to pass s The electric angular velocity ω after e That is, not to make the phase-changed electric angular velocity |ω e The phase is changed in a manner close to the actual electric angular velocity 201, rather than in a manner close to the prediction as the time T is elapsed. s The electric angular velocity ω was obtained later. e Changing the electric angular velocity ω e The phase. Thus, by changing the electric angular velocity ω e The phase of the motor 9 can be controlled particularly appropriately when the motor 9 is controlled in an overmodulated state by voltage phase control.

[0198] Furthermore, the control method for the electric motor 9 in this embodiment and / or its variations is based on the required time T. s , making the electric angular velocity ω e The phase is ahead. Therefore, this includes the detected electric angular velocity ω. e The side exceeds the actual electric angular velocity by 201, causing the electric angular velocity ω to... e The phase is ahead. Therefore, when controlling the motor 9 in the overmodulation state by voltage phase control, the motor 9 can be controlled particularly appropriately.

[0199] Furthermore, the control method of the electric motor 9 in this embodiment and / or its modifications reduces the absolute value of the rotational speed N by adjusting the rotational speed parameter (electrical angular velocity ω). e The change in phase (ω) ecmp The rotational speed parameter (electric angular velocity ω) is greater than the absolute value of the rotational speed N when it increases.e The change in phase (ω) ecmp Therefore, when controlling the motor 9 in an overmodulated state via voltage phase control, the motor 9 can be controlled particularly appropriately. For example, deceleration is a time when overcurrent is easily generated due to sudden changes in speed N, so by performing phase change processing specifically during deceleration, the risk of overcurrent can be reduced particularly effectively. In addition, during acceleration, the original response without phase change is maintained, preventing the reduction of control efficiency due to phase change processing caused by instantaneous voltage fluctuations.

[0200] Furthermore, the control method for the electric motor 9 in this embodiment and / or its variations specifically calculates the rotational speed parameter (electrical angular velocity ω). e The time variation of electric angular acceleration (A) e ), the rotational speed parameter (electric angular velocity ω) e The time variation of electric angular acceleration (A) e ) and the specified threshold A e0 Comparisons were made. Furthermore, the rotational speed parameter (electric angular velocity ω) was adjusted. e The time variation of electric angular acceleration (A) e Less than threshold A e0 The amount of change in time (phase change processing) (phase change amount ω) ecmp Less than the rotational speed parameter (electric angular velocity ω) e The time variation of electric angular acceleration (A) e ) is the threshold A e0 The change amount (phase change amount ω) of the above-mentioned changes (phase change processing) ecmp Therefore, when controlling the motor 9 in an overmodulated state via voltage phase control, the motor 9 can be controlled particularly appropriately. For example, since phase-changing processing is limited to rapid acceleration and deceleration such as wheel slippage connected to the motor 9, the risk of overcurrent can be effectively reduced. In addition, during gradual acceleration and deceleration, since the original response is maintained without phase-changing processing, the risk of efficiency degradation caused by temporary voltage overload and the risk of controllability degradation caused by the amplification of noise contained in the detected speed N and the vibration of the voltage applied to the motor 9 can be reduced.

[0201] The control method of the electric motor 9 in this embodiment and / or its variations calculates the rotational speed parameter (electrical angular velocity ω). e The time variation of electric angular acceleration (A) e And the rotational speed parameter (electric angular velocity ω) e The time variation of electric angular acceleration (A) e ) and the specified threshold A e0 Compare the time changes in rotational speed N (electric angular acceleration A) eLess than threshold A e0 At that time, the rotational speed parameter (electric angular velocity ω) is essentially stopped. e The phase change is processed. Therefore, as described above, when controlling the motor 9 in the overmodulation state by voltage phase control, the motor 9 can be controlled particularly appropriately.

[0202] Furthermore, the control method for the electric motor 9 in this embodiment and / or its variations ensures that the control time does not exceed the required time T. s Rotational speed parameters (electric angular velocity ω) e Within the range of changes in ω, the rotational speed parameter (electric angular velocity ω) is measured. e Changes in (electric angular velocity ω) e (Phase changes). Therefore, excessive changes can be prevented, which in turn reduces the risk of increased overcurrent.

[0203] The embodiments of the present invention have been described above. However, the structures described in the above embodiments and various modifications are merely examples of the application of the present invention and are not intended to limit the technical scope of the present invention.

Claims

1. A control method of an electric motor that controls the electric motor by voltage phase control based on a voltage command value that indicates a magnitude of a voltage to be supplied to the electric motor and a voltage phase command value that indicates a phase of the voltage, wherein a required time required when a final command value of the voltage applied to the electric motor by the voltage phase control is calculated using a rotational speed parameter related to a rotational speed of the electric motor according to a command value calculation model is acquired, the rotational speed parameter is detected, a phase of the detected rotational speed parameter is advanced based on the required time so that the rotational speed parameter approaches the rotational speed parameter after the required time elapses, whereby the rotational speed parameter is changed, and the final command value is calculated using the changed rotational speed parameter according to the command value calculation model.

2. The control method of an electric motor according to claim 1, wherein the rotational speed parameter is an electrical angular velocity.

3. The control method of an electric motor according to claim 1, wherein a change amount of the rotational speed parameter when an absolute value of the rotational speed decreases is larger than a change amount of the rotational speed parameter when the absolute value of the rotational speed increases.

4. The control method of an electric motor according to claim 1, wherein a time change of the rotational speed parameter is calculated, the time change of the rotational speed parameter is compared with a prescribed threshold value, and a change amount of the rotational speed parameter when the time change of the rotational speed parameter is smaller than the threshold value is smaller than a change amount of the rotational speed parameter when the time change of the rotational speed parameter is the threshold value or more.

5. The control method of an electric motor according to claim 1, wherein a time change of the rotational speed parameter is calculated, the time change of the rotational speed parameter is compared with a prescribed threshold value, and the change of the rotational speed parameter is suspended when the time change of the rotational speed parameter is smaller than the threshold value.

6. The control method of an electric motor according to any one of claims 1 to 5, wherein the change of the rotational speed parameter is performed within a range in which a change amount of the rotational speed parameter per the required time is not exceeded.

7. An electric motor system that includes: an electric motor; and a controller that controls the electric motor by voltage phase control based on a voltage command value that indicates a magnitude of a voltage to be supplied to the electric motor and a voltage phase command value that indicates a phase of the voltage, wherein the controller performs the following processing: acquiring a required time required when a final command value of the voltage applied to the electric motor by the voltage phase control is calculated using a rotational speed parameter related to a rotational speed of the electric motor according to a command value calculation model, detecting the rotational speed parameter, advancing a phase of the detected rotational speed parameter based on the required time so that the rotational speed parameter approaches the rotational speed parameter after the required time elapses, whereby the rotational speed parameter is changed, and calculating the final command value using the changed rotational speed parameter according to the command value calculation model. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ wherein, ​ ​ ​ ​ ​

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