Motor control method and motor control device

Abstract

To provide a motor control method by which a disturbance suppression property is enhanced.SOLUTION: There is provided a motor control method for controlling a stator current flowing through a stator winding and a rotor current flowing through a rotor in a winding field synchronous motor that includes the rotor having a rotor winding and the stator having a stator winding. In this motor control method, a non-interfering voltage for preventing not only an interference voltage between a d-axis and a q-axis of the stator current but also an interference voltage between an f-axis of the rotor current and the d-axis and the q-axis, from causing interference, is calculated on the basis of a d-axis current command value, a q-axis current command value, an f-axis current command value, and the rotational state of the motor, and the d-axis, q-axis, and f-axis voltage command values are corrected with use of the d-axis, q-axis, and f-axis components of the non-interfering voltage. Further, a disturbance voltage is estimated on the basis of the corrected voltage command values, and the voltage command values are corrected in accordance with the estimated disturbance voltage.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a motor control method and a motor control device.

Background Art

[0002] Patent Document 1 discloses a control device that removes the influence of disturbances applied to a motor by a feedback compensator. For a synchronous motor that performs dq-axis conversion control, this control device performs disturbance compensation for each of the d-axis current and the q-axis current to be controlled using independent feedback compensators.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the control device of Patent Document 1, disturbance compensation is performed without considering the interference between the controlled objects (between the d-axis current and the q-axis current). For this reason, there is a problem that the estimation accuracy of the disturbance deteriorates as the interference between the axes of the controlled object increases.

[0005] In particular, in a wound-field synchronous motor having a field winding (rotor winding) on the rotor, the interference voltage between the d-axis and q-axis of the stator current and the f-axis of the rotor current is large. Therefore, when the control device of Patent Document 1 is applied to a wound-field synchronous motor, there is a risk that the estimation accuracy of the disturbance will deteriorate significantly due to the influence of the interference voltage between the d-axis, q-axis, and f-axis. As a result, the disturbance suppression performance deteriorates, and when a current deviation occurs due to a disturbance, the time until the deviation disappears becomes longer.

[0006] In view of the above problems, an object of the present invention is to provide a motor control method and a motor control device with improved disturbance suppression performance.

Means for Solving the Problem

[0007] According to one aspect of the present invention, there is provided a motor control method for controlling a stator current flowing through a stator winding and a rotor current flowing through a rotor in a wound field synchronous motor including a rotor having a rotor winding and a stator having a stator winding. In this motor control method, a first d-axis voltage command value and a first q-axis voltage command value are calculated based on a d-axis current command value and a q-axis current command value with respect to the stator current, and a first f-axis voltage command value is calculated based on an f-axis current command value with respect to the rotor current. Based on the d-axis current command value, the q-axis current command value, the f-axis current command value, and the rotational state of the motor, an interference voltage not only between the d-axis and the q-axis of the stator current but also an interference voltage between the d-axis and the q-axis and the f-axis of the rotor current is calculated. An interference voltage for non-interference is calculated, and the first d-axis voltage command value, the first q-axis voltage command value, and the first f-axis voltage command value are corrected using the d-axis component of the interference voltage, the q-axis component of the interference voltage, and the f-axis component of the interference voltage, respectively, to calculate a second d-axis voltage command value, a second q-axis voltage command value, and a second f-axis voltage command value. Based on the final d-axis voltage command value and the final q-axis voltage command value for the stator, the final f-axis voltage command value for the rotor, the stator current, and the rotor current, estimated values of the d-axis disturbance voltage, the q-axis disturbance voltage, and the f-axis disturbance voltage are calculated. Then, the second d-axis voltage command value, the second q-axis voltage command value, and the second f-axis voltage command value are corrected using the estimated values of the d-axis disturbance voltage, the q-axis disturbance voltage, and the f-axis disturbance voltage to calculate the final d-axis voltage command value, the final q-axis voltage command value, and the final f-axis voltage command value. The calculated final d-axis voltage command value and final q-axis voltage command value are used to control the stator current, and the final f-axis voltage command value is used to control the rotor current.

Advantages of the Invention

[0008] According to the motor control method of the present invention, an interference voltage is calculated not only between the d-axis and the q-axis but also between the d-axis and the q-axis and the f-axis to cancel the interference voltage, and the d-axis, q-axis, and f-axis voltage command values are corrected using the d-axis, q-axis, and f-axis components of the interference voltage. Therefore, since the disturbance voltage is estimated based on the voltage command value in which not only the interference voltage between the d-axis and the q-axis but also the interference voltage between the d-axis and the q-axis and the f-axis is canceled, the estimation accuracy of the disturbance is improved and the disturbance suppression performance is improved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Mode for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings and the like.

[0011] FIG. 1 is a block diagram showing the configuration of a motor control system 100 to which the motor control method according to the present embodiment is applied.

[0012] The motor control system 100 is a system that controls the operation of a motor 101 configured as a wound-field synchronous motor. The motor control system 100 is mounted on, for example, an electric vehicle (EV) or a hybrid electric vehicle (HEV).

[0013] As shown in FIG. 1, the motor control system 100 of this embodiment includes a motor 101 to be controlled, a PWM converter 102, an inverter 103, a power supply voltage 104, a field current output unit 105, a current sensor 106, an A / D converter 107, a three-phase / d-q AC coordinate converter 108, a magnetic pole position detector 109, a pulse counter 110, an angular velocity calculator 111, a look-ahead compensation unit 112, a current command value calculator 113, a current control unit 114, a non-interference control unit 115, a second voltage command value calculator 116, a disturbance compensation unit 117, a final voltage command value calculator 118, and a d-q / three-phase AC coordinate converter 119.

[0014] The motor 101 is a wound-field synchronous motor including a rotor having a rotor winding (field winding, rotor coil) and a stator having a stator winding (armature winding, stator coil). The motor 101 can be used as a power source for various driving force required devices. When the motor control system 100 of this embodiment is mounted on a vehicle, the motor 101 serves as a driving source of the vehicle. The motor 101 is controlled by controlling a rotor current flowing through the rotor winding and a stator current flowing through the stator winding.

[0015] Based on the three-phase voltage command values v * u , v * v , v * w output from the d-q / three-phase AC coordinate converter 119 described later, the PWM converter 102 generates PWM_Duty drive signals (high-power element drive signals) D * uu , D * ul , D * vu , D * vl , D * wu , D * wl for the switching elements (e.g., IGBTs) included in the inverter 103 and outputs them to the inverter 103.

[0016] The inverter 103 is a three-phase voltage source inverter composed of three phases and six arms, with a total of six switching elements, two for each phase. The inverter 103 converts the DC voltage of the power supply voltage 104 into an AC voltage v u , v v , v w based on the high-power device drive signal generated by the PWM converter 102 and supplies it to the motor 101.

[0017] The power supply voltage 104 is, for example, a laminated lithium-ion battery. The power supply voltage 104 supplies DC power to the inverter 103 and the field current output section 105.

[0018] The field current output section 105 uses the power supplied from the power supply voltage 104 to output an f-axis voltage v f for controlling the field (f-axis) current i f flowing through the rotor winding of the motor 101. The f-axis voltage v f is calculated according to the final f-axis voltage command value v * f output from the final voltage command value calculation section 118 described later. In other words, the field current output section 105 adjusts the f-axis voltage v f applied to the rotor winding so that it matches the final f-axis voltage command value v * f .

[0019] The current sensor 106 detects at least two-phase currents among the three-phase alternating current supplied from the inverter 103 to the motor 101, for example, the u-phase current i u , and the v-phase current i v . The detected two-phase currents i u , i v are converted into digital signals (currents i us , i vs ) by an A / D (analog / digital) converter 107 and input to a three-phase / d-q AC coordinate converter 108. When the current sensor 106 detects only two-phase currents, the remaining one-phase current i ws can be obtained by the following formula (1).

[0020]

Number

[0021] Also, the current sensor 106 detects the rotor current (f-axis current i f ) supplied from the field current output section 105 to the motor 101. The detected f-axis current i f is converted into a digital signal by the A / D converter 107 and output to the field current control section and the disturbance compensation section 117 in the current control section 114 described later.

[0022] The pole position detector 109 outputs A-phase, B-phase, and Z-phase pulses (ABZ pulses) corresponding to the position (angle) of the stator of the motor 101 to the pulse counter 110 in order to obtain the electrical angle of the stator of the motor 101.

[0023] The pulse counter 110 calculates the electrical angle θ re of the motor 101 based on the ABZ pulses and outputs it to the angular velocity calculator 111.

[0024] The angular velocity calculator 111 calculates the electrical angular velocity ω re and the mechanical angular velocity ω re from the time change rate of the input electrical angle θ rm . The mechanical angular velocity ω rm is obtained by dividing the electrical angular velocity ω re by the number of motor pole pairs p. The mechanical angular velocity ω rm is output to the current command value calculation section 113. The electrical angular velocity ω re is output to the non-interference control section 115 and the look-ahead compensation section 112.

[0025] The look-ahead compensation section 112 calculates the look-ahead compensated electrical angle θ re and the electrical angular velocity ω re as inputs, and adds the product of the electrical angular velocity ω re and the dead time of the control system to the electrical angle θ re to calculate the look-ahead compensated electrical angle θ re ’. The look-ahead compensated electrical angle θ re ’ is output to the d-q / 3-phase AC coordinate converter 119.

[0026] The three-phase / d-q AC coordinate converter 108 performs conversion from a three-phase AC coordinate system (uvw axes) to a two-axis orthogonal DC coordinate system (d-q axes). Specifically, the three-phase / d-q AC coordinate converter 108 receives the input u-phase current i us , v-phase current i vs , and electrical angle θ re , and the w-phase current i ws obtained by the above formula (1), and performs coordinate conversion processing using the following formula (2) to calculate the d-axis current i d and the q-axis current i q . The calculated d-axis current i d and q-axis current i q are output to the current control unit 114 and the disturbance compensation unit 117 described later.

[0027]

Equation

[0028] The current command value calculation unit 113 takes the torque command value T * , the motor rotation speed (mechanical angular velocity ω rm ), and the power supply voltage (DC voltage) V dc as inputs, and calculates the d-axis current command value i * d , the q-axis current command value i * q , and the f-axis current command value i * f . The d-axis current command value i * d , the q-axis current command value i * q , and the f-axis current command value i * f are based on the torque command value T * , the motor rotation speed (mechanical angular velocity ω rm ), and the power supply voltage V dc , and the d-axis current command value i * d , the q-axis current command value i * q , and the f-axis current command value i * fMap data defining the relationship with each of them is stored in advance, and it is obtained by referring to the map data.

[0029] The current control unit 114 includes a d-axis current control unit to which the d-axis current i calculated by the three-phase / d-q AC coordinate converter 108 is input, a q-axis current control unit to which the q-axis current i calculated by the three-phase / d-q AC coordinate converter 108 is input, and a field current control unit to which the f-axis current i is input. d The d-axis current control unit makes the d-axis current i, which is the measured value of the actual stator current (actual current), follow the d-axis current command value i with a desired responsiveness without a steady-state deviation. From this perspective, the first d-axis voltage command value v is calculated by PI control with the deviation between the d-axis current command value i and the d-axis current i as the input. Similarly, the q-axis current control unit makes the q-axis current i, which is the measured value of the actual stator current (actual current), follow the q-axis current command value i with a desired responsiveness without a steady-state deviation. From this perspective, the first q-axis voltage command value v is calculated by PI control with the deviation between the q-axis current command value i and the q-axis current i as the input. Also, the field current control unit makes the f-axis current i, which is the measured value of the actual rotor current (actual current), follow the f-axis current command value i with a desired responsiveness without a steady-state deviation. From this perspective, the first f-axis voltage command value v is calculated by PI control with the deviation between the f-axis current command value i and the f-axis current i as the input. The calculated first d-axis voltage command value v q The q-axis current control unit, and the field current control unit to which the f-axis current i is input. f is composed of.

[0030] The d-axis current control unit makes the d-axis current i, which is the measured value of the actual stator current (actual current), follow the d-axis current command value i with a desired responsiveness without a steady-state deviation. From this perspective, the d-axis current command value i d and the d-axis current i * d with a desired responsiveness without a steady-state deviation. From this perspective, the d-axis current command value i * d and the d-axis current i d is input, and the first d-axis voltage command value v * d1 is calculated by PI control. Similarly, the q-axis current control unit makes the q-axis current i, which is the measured value of the actual stator current (actual current), follow the q-axis current command value i with a desired responsiveness without a steady-state deviation. From this perspective, the q-axis current command value i q and the q-axis current i * q with a desired responsiveness without a steady-state deviation. From this perspective, the q-axis current command value i * q and the q-axis current i q is input, and the first q-axis voltage command value v * q1 is calculated by PI control. Also, the field current control unit makes the f-axis current i, which is the measured value of the actual rotor current (actual current), follow the f-axis current command value i with a desired responsiveness without a steady-state deviation. From this perspective, the f-axis current command value i f and the f-axis current i * f with a desired responsiveness without a steady-state deviation. From this perspective, the f-axis current command value i * f and the f-axis current i f is input, and the first f-axis voltage command value v * f1 is calculated by PI control. The calculated first d-axis voltage command value v * d1, the first q-axis voltage command value v * q1 and the first f-axis voltage command value v * f1 are output to the second voltage command value calculation unit 116.

[0031] The non-interference control unit 115 uses the electrical angular velocity ω re , the d-axis current command value i * d , the q-axis current command value i * q , and the f-axis current command value i * f as inputs, and based on these input values, calculates and outputs the non-interference voltages v d_dcpl , v q_dcpl , v f_dcpl required to cancel the interference voltages between the d-axis, q-axis, and f-axis. That is, in the non-interference control unit 115, not only the interference voltage between the d-axis and q-axis but also the interference voltages between the d-axis and q-axis and the f-axis are non-interfered by the non-interference voltages v d_dcpl , v q_dcpl , v f_dcpl are calculated.

[0032] The second voltage command value calculation unit 116 corrects (adds in this embodiment) the first d-axis voltage command value v * d1 , the first q-axis voltage command value v * q1 and the first f-axis voltage command value v * f1 using the d-axis component v d_dcpl , q-axis component v q_dcpl , and f-axis component v f_dcpl of the non-interference voltage, which are the outputs of the non-interference control unit 115, to obtain the second d-axis voltage command value v * d2 , the second q-axis voltage command value v * q2 , and the second f-axis voltage command value v * f2 .

[0033] The disturbance compensation unit 117 receives the electrical angular velocity ω re , the d-axis current i d , the q-axis current iq and the f-axis current i f and the final d-axis voltage command value v * fd output from the final voltage command value calculation unit 118 described later, the final q-axis voltage command value v * q and the final f-axis voltage command value v * f are input. Based on these input values, the disturbance compensation unit 117 calculates the estimated values of the disturbances on each axis input to the motor 101, and calculates the estimated d-axis disturbance voltage v d_dist_est , the estimated q-axis disturbance voltage v q_dist_est and the estimated f-axis disturbance voltage v f_dist_est and outputs them. The details of the disturbance compensation unit 117 will be described later.

[0034] The final voltage command value calculation unit 118 corrects (adds in this embodiment) the second voltage command value corrected by the second voltage command value calculation unit 116 using the estimated d-axis disturbance voltage v d_dist_est , the estimated q-axis disturbance voltage v q_dist_est and the estimated f-axis disturbance voltage v f_dist_est to obtain the final d-axis voltage command value v * fd , the final q-axis voltage command value v * q and the final f-axis voltage command value v * f The obtained final d-axis voltage command value v * d and the final q-axis voltage command value v * q are output to the disturbance compensation unit 117 and the d-q / 3 phase AC coordinate converter 119, and the final f-axis voltage command value v * f for the rotor is output to the disturbance compensation unit 117 and the field current output unit 105.

[0035] The d-q / 3 phase AC coordinate converter 119 performs a conversion from a two-axis DC coordinate system (d-q axis) rotating at the electrical angular velocity ω re to a three-phase AC coordinate system (uvw phase). Specifically, the d-q / 3 phase AC coordinate converter 119, the input final d-axis voltage command value v *d , the final q-axis voltage command value v * q , and the electrical angle θ after the look-ahead compensation re ’, the voltage command values v of each of the uvw phases are calculated by performing coordinate conversion processing using the following equation (3). * u v * v v * w are calculated.

[0036]

Equation

[0037] The above is an overview of the configuration of the motor control system 100 according to the present embodiment. In the present embodiment, among the above-described configurations, the PWM converter 102, the A / D converter 107, the three-phase / d-q AC coordinate converter 108, the pulse counter 110, the angular velocity calculator 111, the look-ahead compensation unit 112, the current command value calculator 113, the current control unit 114, the non-interference control unit 115, the second voltage command value calculator 116, the disturbance compensation unit 117, and the final voltage command value calculator 118, the d-q / three-phase AC coordinate converter 119 are configured as at least one or more functional units provided in the controller 10. The controller 10 is composed of, for example, a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface).

[0038] Hereinafter, the details of the disturbance compensation unit 117 will be described. First, the voltage equation used in the disturbance compensation unit 117 of the present embodiment will be described. The voltage equation of the wound-field synchronous motor 101, which is the control object of the present invention, is represented by the following equation (4) using the transfer function G p (s).

[0039]

Equation

[0040] However, the transfer function G p(s) is represented by the following formula (5).

[0041] [Number]

[0042] Also, each parameter of the above formula (4) and formula (5) is as follows. Here, s in the formula is the Laplace operator. i d : d-axis current i q : q-axis current i f : f-axis current v d : d-axis voltage v q : q-axis voltage v f : f-axis voltage L d : d-axis inductance L q : q-axis inductance L f : f-axis inductance M: Mutual inductance between stator / rotor L d ’: d-axis dynamic inductance L q ’: q-axis dynamic inductance L f ’: f-axis dynamic inductance M’: Dynamic mutual inductance between stator / rotor R a : Stator winding resistance R f : Rotor winding resistance ω re : Electrical angular velocity

[0043] Here, the transfer function G p (s) is set based on the rotational state parameters including the electrical angular velocity ω re of the motor 101 and has interference components (off-diagonal components) between the d-axis component, q-axis component, and f-axis component as shown in formula (5). That is, the transfer function G p(s) includes the interference characteristics of the motor.

[0044] Next, with reference to FIG. 2, the details of the disturbance compensation unit 117 will be described.

[0045] FIG. 2 is a block diagram for explaining a method of calculating a disturbance estimation value in the disturbance compensation unit 117.

[0046] In the disturbance compensation unit 117, the first voltage estimation value calculated by a filter process using the measured actual current as an input is subtracted from the second voltage estimation value calculated by a filter process using the final voltage command value as an input, thereby calculating a disturbance estimation value. Hereinafter, the details of the method of calculating the disturbance estimation value will be described.

[0047] The first voltage estimation value includes the first d-axis voltage estimation value v d_est1 , the first q-axis voltage estimation value v q_est1 , and the first f-axis voltage estimation value v f_est1 , and is calculated by the following formula (6) based on the d-axis current i d , q-axis current i q , which is the measured actual stator current, and the f-axis current i f which is the rotor (field) current.

Equation

[0048] However, G p -1 (s) is the inverse system of the plant (the inverse system of the transfer function G p (s)) and is represented by the following formula (7).

[0049]

Equation

[0050] Also, H(s) is a first-order lag filter whose time constant is individually set for each of the d-axis component, q-axis component, and f-axis component, and is represented by the following formula (8).

[0051] [Number]

[0052] However, τ in Equation (8) hd is the time constant for the d-axis component (d-axis time constant), τ hq is the time constant for the q-axis component (q-axis time constant), τ hf is the time constant for the f-axis component (f-axis time constant). The time constant of H(s) can be set arbitrarily. In this embodiment, the time constant τ hf for the f-axis is set to be larger than the time constant τ hd for the d-axis and the time constant τ hq for the q-axis.

[0053] As shown in Equation (6), the first voltage estimation values v d_est1 , v q_est1 , v f_est1 are calculated by applying the first-order lag filter H(s) and the inverse system G d of the plant to the measured actual currents i q , i f . p -1 (s).

[0054] Note that the difference between the denominator degree and the numerator degree of the first-order lag filter H(s) is greater than or equal to the difference between the denominator degree and the numerator degree of the transfer function G p (s). By introducing such a first-order lag filter H(s), it is possible to avoid non-properties caused by using the inverse system G p (s) of the transfer function G p -1 (s) that includes the interference characteristics of the motor in the calculation of the first voltage estimation value.

[0055] Block 201 in FIG. 2 shows the calculation method of the first voltage estimation values v d_est1 , v q_est1 , v f_est1 . As shown in Block 201, the d-axis current i d , the q-axis current i q , which are the measured actual stator currents, and the f-axis current i f , which is the rotor (field) current,Using this as the input, filter processing is performed by applying a first-order lag filter H(s) and the inverse system G p -1 (s) of the plant, and first voltage estimation values v d_est1 、v q_est1 、v f_est1 are calculated. The first d-axis voltage estimation value v d_est1 、the first q-axis voltage estimation value v q_est1 、and the first f-axis voltage estimation value v f_est1 calculated by the filter processing are output to the disturbance estimation value calculation unit 203.

[0056] The second voltage estimation value includes the second d-axis voltage estimation value v d_est2 、the second q-axis voltage estimation value v q_est2 、and the second f-axis voltage estimation value v f_est2 and is calculated by the following formula (9) based on the final voltage command value (final d-axis voltage command value v * d 、final q-axis voltage command value v * q 、final f-axis voltage command value v * f ).

[0057]

Equation

[0058] As shown in formula (9), the second voltage estimation values v d_est2 、v q_est2 、v f_est2 are calculated by applying the first-order lag filter H(s) to the final voltage command value (final d-axis voltage command value v * d 、final q-axis voltage command value v * q 、final f-axis voltage command value v * f ).

[0059] Block 202 in Figure 2 shows the calculation method of the second voltage estimation values v d_est2 、v q_est2 、v f_est2 shown above. As shown in block 202, the final d-axis voltage command value v* d , the final q-axis voltage command value v * q , the final f-axis voltage command value v * f As inputs, filter processing is performed by applying a first-order lag filter H(s), and second voltage estimated values v d_est2 , v q_est2 , v f_est2 are calculated. The second d-axis voltage estimated value v d_est2 , the second q-axis voltage estimated value v q_est2 , and the second f-axis voltage estimated value v f_est2 are output to the disturbance estimated value calculation unit 203.

[0060] Here, the final voltage command values v * d , v * q , v * f are voltage command values corrected by non-interference voltages v d_dcpl , v q_dcpl , v f_dcpl to cancel not only the interference voltage between the d-axis and the q-axis but also the interference voltage between the d-axis and q-axis and the f-axis (non-interference control unit 115, second voltage command value calculation unit 116). That is, the second voltage estimated values v d_est2 , v q_est2 , v f_est2 are calculated based on the voltage command values with the interference voltage between the d-axis, q-axis, and f-axis canceled.

[0061] The disturbance estimated value calculation unit 203 calculates an estimated value of the disturbance voltage. Specifically, from the second d-axis voltage estimated value v d_est2 , the second q-axis voltage estimated value v q_est2 , and the second f-axis voltage estimated value v f_est2 , the first d-axis voltage estimated value v d_est1 , the first q-axis voltage estimated value v q_est1 , and the first f-axis voltage estimated value v f_est1 are subtracted to calculate a d-axis disturbance voltage estimated value v d_dist_est , a q-axis disturbance voltage estimated value v q_dist_est and an f-axis disturbance voltage estimated value v f_dist_est The calculated d-axis disturbance voltage estimated value vd_dist_est and the estimated value v of the q-axis disturbance voltage q_dist_est and the estimated value v of the f-axis disturbance voltage f_dist_est are output to the final voltage command value calculation unit 118. As described above, in the final voltage command value calculation unit 118, the disturbance voltage estimated value v d_dist_est , v q_dist_est , v f_dist_est calculated for the second voltage command value is added to obtain the final d-axis voltage command value v * d , the final q-axis voltage command value v * q and the final f-axis voltage command value v * f .

[0062] As described above, in the disturbance compensation unit 117, not only the interference voltage between the d-axis and the q-axis but also the interference voltage between the d-axis and the q-axis and the f-axis is made non-interfering, and the final voltage command value v * d , v * q , v * f is used to estimate the disturbance voltage, so the estimation accuracy of the disturbance is improved.

[0063] Also, in the disturbance compensation unit 117, the disturbance voltage is estimated based on the inverse system G p (s) of the transfer function G p -1 (s) including the interference characteristics of the motor, and in the final voltage command value calculation unit 118, the second voltage command value v * d2 , v * q2 , v * f2 is added to the estimated disturbance voltage value v d_dist_est , v q_dist_est , v f_dist_est calculated for it to cancel the disturbance. Here, the transfer function G p (s) includes the interference characteristics not only between the d-axis and the q-axis but also between the d-axis and the q-axis and the f-axis. Therefore, even if there is interference between the d-axis, the q-axis, and the f-axis, the disturbance can be accurately estimated.

[0064] Also, the transfer function G p(s) and transfer function G p Inverse system G of (s) p -1 The off-diagonal components of (s) are the electrical angular velocity ω which is the angular velocity of the motor 101 as the rotational state parameter re including. That is, the electrical angular velocity ω re The off-diagonal components are set using the detected value (the magnetic pole position detector 109, the pulse counter 110, and the angular velocity calculator 111 in FIG. 1) of. Thereby, the off-diagonal components are set according to the detected value of the electrical angular velocity ω re which correlates with the actual rotational state of the motor 101. Accordingly, the off-diagonal components of the transfer function G p (s) are set. Therefore, the transfer function G p (s) in which the interference components between the d-axis, q-axis, and f-axis are more appropriately evaluated according to the actual operating state of the motor 101 can be set, and the estimation accuracy of the disturbance is further improved.

[0065] Also, in the disturbance compensation unit 117, a first-order lag filter H(s) whose time constant is individually set for each of the d-axis component, q-axis component, and f-axis component is used. Here, the smaller the filter time constant is set, the better the responsiveness to the input becomes, and the estimation speed of the disturbance is improved, but the control stability deteriorates and the control is likely to diverge. Therefore, the estimation speed of the disturbance voltage and the control stability can be adjusted according to the characteristics of each of the d-axis, q-axis, and f-axis.

[0066] In particular, there is an order-level difference between the inductance of the stator winding and the inductance of the field (rotor) winding, and there is a large difference between the characteristics of the d-axis and q-axis and the characteristics of the f-axis. Therefore, when the time constant τ hd for the d-axis and the time constant τ hq for the q-axis and the time constant τ hf for the f-axis are set to the same value (not set individually), due to the constraint of the field winding with a large inductance, the time constant τ hd for the d-axis and the time constant τ hq for the q-axis are set to the time constant τ hfIt has to be set large accordingly. In this case, the estimation speed of the disturbance voltages on the d-axis and q-axis becomes slow, and there is a risk that the disturbance suppression performance cannot be improved. On the other hand, in the present embodiment, the time constant of the first-order lag filter H(s) is set individually for each of the d-axis component, q-axis component, and f-axis component, and the time constant τ hf for the f-axis is set larger than the time constant τ hd for the d-axis and the time constant τ hq for the q-axis. Therefore, both control stability and disturbance suppression performance can be achieved.

[0067] FIG. 3 is a flowchart for explaining the motor control method according to the present embodiment. One control cycle from the start to the end shown in FIG. 3 is programmed in the controller 10 so as to be constantly executed at regular intervals while the motor control system 100 is operating.

[0068] In step S11, the controller 10 (pulse counter 110, A / D converter 107) calculates the electrical angle θ re based on the ABZ pulses, and detects the currents i u , i v of the acquired u-phase and v-phase, and the f-axis current i f flowing through the rotor winding, and detects the currents i us , i vs , i fs as digital signals.

[0069] In step S12, the controller 10 (angular velocity calculator 111) calculates the electrical angular velocity ω re and the mechanical angular velocity ω re from the time change rate of the input electrical angle θ rm .

[0070] In step S13, the controller 10 (look-ahead compensator 112) calculates the look-ahead compensated electrical angle θ re ' taking into account the dead time of the control system from the electrical angle θ re and the electrical angular velocity ω re .

[0071] In step S14, the controller 10 (3-phase / d-q AC coordinate converter 108) calculates the d-axis and q-axis currents i us , i vs , i ws , and the electrical angle θ re to calculate the d-axis and q-axis currents i d , i q .

[0072] In step S15, the controller 10 (current command value calculation unit 113) calculates the d-axis current command value i * , the motor speed (mechanical angular velocity ω rm ), and the power supply voltage V dc to calculate the d-axis current command value i * d , the q-axis current command value i * q , and the f-axis current command value i * f .

[0073] In step S16, the controller 10 (current control unit 114) calculates the first voltage command values v d , i q , i f of each phase of the d-axis, q-axis, and f-axis to make the d-axis, q-axis, and f-axis currents i * d , i * q , i * f follow the desired responsiveness without a steady-state deviation to the d-axis, q-axis, and f-axis current command values i * d1 , v * q1 , v * f1 .

[0074] In step S17, the controller 10 (decoupling control unit 115) calculates the decoupling voltage v * d , i * q , i * f and the electrical angular velocity ω re to cancel the interference voltage between the d-axis, q-axis, and f-axis d_dcpl, v q_dcpl , v f_dcpl are calculated.

[0075] In step S18, the controller 10 (second voltage command value calculation unit 116) corrects (adds) the first voltage command values v * d1 , v * q1 , v * f1 of the d, q, and f axes respectively using the d-axis component v d_dcpl of the non-interference voltage, the q-axis component v q_dcpl , and the f-axis component v f_dcpl to calculate the second voltage command values v * d2 , v * q2 , v * f2 of the d, q, and f axes.

[0076] In step S19, the controller 10 (disturbance compensation unit 117) uses the measured actual currents i d , i q , i f of the d, q, and f axes, the electrical angular velocity ω re , and the final voltage command values v * d , v * q , v * f to calculate (estimate) the disturbance voltage estimation values v d_dist_est , v q_dist_est , v f_dist_est input to the motor 101 for each axis. As described above, the disturbance voltage estimation values v d_dist_est , v q_dist_est , v f_dist_est are calculated using the inverse system G p (s) of the transfer function G p -1 (s) including the interference characteristics of the motor and the first-order lag filter H(s) with time constants set for each of the d, q, and f axis components.

[0077] In step S20, the controller 10 (final voltage command value calculation unit 118) uses the second voltage command values v* d2 , v * q2 , v * f2 is corrected (added) using the calculated disturbance voltage estimated values v d_dist_est , v q_dist_est , v f_dist_est to calculate the final voltage command value v * d , v * q , v * f .

[0078] In step S21, the controller 10 (d-q / 3-phase AC coordinate converter 119) calculates the voltage command values v * d of the final d-axis, the voltage command value v * q of the final q-axis, and the electrical angle θ re ' after predictive compensation for each phase voltage command value v * u , v * v , v * w .

[0079] The above is an outline of the control flow by the motor control method of this embodiment.

[0080] Fig. 4A is a timing chart showing the change over time of the disturbance estimated value as the simulation result in this embodiment and the comparative example. Fig. 4B is a timing chart showing the change over time of the current detection value as the simulation result in this embodiment and the comparative example. The comparative example is the simulation result when disturbance compensation is performed by independent feedback compensation for each of the d-axis, q-axis, and f-axis without considering the interference between the d-axis, q-axis, and f-axis.

[0081] The horizontal axis of FIG. 4A represents time, and the vertical axis represents, in order from the top, the d-axis disturbance voltage [V], the q-axis disturbance voltage [V], and the f-axis disturbance voltage [V]. The dashed line in the figure represents the actually input disturbance, the solid line represents the estimated value of the disturbance according to this embodiment, and the alternate long and short dash line represents the estimated value of the disturbance according to the comparative example.

[0082] Also, the horizontal axis of FIG. 4B represents time, and the vertical axis represents, in order from the top, the d-axis current [A], the q-axis current [A], and the f-axis current [A]. The dashed line in the figure represents the current command value, the solid line represents the actual current (detected value of the current) according to this embodiment, and the alternate long and short dash line represents the actual current (detected value of the current) according to the comparative example.

[0083] As shown in FIG. 4A, when an actual disturbance is input at time t1, compared with the comparative example, the estimated value of the disturbance according to this embodiment is determined as a highly accurate value closer to the actually input disturbance. Also, as shown in FIG. 4B, the current deviation caused by the influence of the disturbance converged more quickly compared with the comparative example.

[0084] According to the motor control method of the above-described embodiment, the following effects can be obtained.

[0085] The motor control method of this embodiment is based on the current command values i * d 、i * q 、i * f and the rotational state of the motor to calculate non-interference voltages v d_dcpl 、v q_dcpl 、v f_dcpl for non-interfering not only the interference voltage between the d-axis and the q-axis of the stator current but also the interference voltage between the d-axis and the q-axis and the f-axis of the rotor current. Then, the d-axis component v d_dcpl 、the q-axis component v q_dcpl 、and the f-axis component v f_dcpl of the non-interference voltage are used to correct the d-axis, q-axis, and f-axis voltage command values, respectively. Therefore, since the disturbance voltage is estimated based on the voltage command value in which not only the interference voltage between the d-axis and the q-axis but also the interference voltage between the d-axis and the q-axis and the f-axis is non-interfered, the estimation accuracy of the disturbance is improved and the disturbance suppression performance is improved.

[0086] The motor control method of this embodiment is such that the estimated values of the d-axis disturbance voltage, q-axis disturbance voltage, and f-axis disturbance voltage are obtained based on the transfer function G p (s) representing the transfer characteristics from the voltage to the current of the motor 101, and the inverse system G p -1 (s) of the transfer function G p (s) includes interference components among the d-axis component, q-axis component, and f-axis component. That is, since the transfer function G p (s) includes the interference characteristics not only between the d-axis and q-axis but also between the d-axis and q-axis and the f-axis, even if there is interference among the d-axis, q-axis, and f-axis, the disturbance can be accurately estimated, and the disturbance suppression performance is further improved.

[0087] The motor control method of this embodiment is such that the transfer function G p (s) is set based on the rotational state parameters including the electrical angular velocity ω re of the motor 101, and the electrical angular velocity ω re is the detected value by a sensor. That is, the transfer function G re (s) is set according to the detected value of the electrical angular velocity ω p corresponding to the actual rotational state of the motor 101. Therefore, the transfer function G p (s) in which the interference components among the d-axis, q-axis, and f-axis are more appropriately evaluated according to the actual operating state of the motor 101 can be set, and the estimation accuracy of the disturbance is further improved.

[0088] The motor control method of this embodiment is such that the actual currents i d 、i q 、i f are passed through a first-order lag filter H(s) whose difference between the denominator degree and the numerator degree is greater than or equal to the difference between the denominator degree and the numerator degree of the transfer function G p (s) and the inverse system G p (s) of the transfer function G p -1 (s) to calculate the first voltage estimated values v d_est1 、v q_est1 、v f_est1 。Further, the final voltage command values v * d 、v * q 、v* f Apply a first-order lag filter H(s) to obtain a second voltage estimation value v d_est2 , v q_est2 , v f_est2 . Then, by subtracting the first voltage estimation values v d_est2 , v q_est2 , v f_est2 from the second voltage estimation values v d_est1 , v q_est1 , v f_est1 , estimate the disturbance voltages on the d-axis, q-axis, and f-axis. In this way, in the estimation of the disturbance voltage, a first-order lag filter H(s) is introduced whose difference between the denominator degree and the numerator degree is equal to or greater than the difference between the denominator degree and the numerator degree of the transfer function G p (s). As a result, in the estimation of the disturbance voltage, the non-properness caused by using the inverse system G p (s) of the transfer function G p -1 (s) can be avoided.

[0089] In the motor control method of this embodiment, the time constant of the first-order lag filter H(s) is set individually for each of the d-axis component, q-axis component, and f-axis component. And the time constant τ hf for the f-axis (the time constant of the first-order lag filter H(s) for the f-axis component) is set to be larger than the time constant τ hd for the d-axis (the time constant of the first-order lag filter H(s) for the d-axis component) and the time constant τ hq for the q-axis (the time constant of the first-order lag filter H(s) for the q-axis component). As a result, the time constants τ hd for the d-axis and τ hq for the q-axis can be set without being restricted by the field winding with a large inductance, the estimation speed of the disturbance voltage is improved, and the disturbance suppression performance is improved. Also, since the time constant τ hq for the q-axis is set large, the control stability is improved. That is, both the control stability and the disturbance suppression performance can be achieved.

[0090] Note that, as in this embodiment, it is preferable to use the detection value by the sensor for the electrical angular velocity ω re , but it is not necessarily limited to this.

[0091] Also, as in this embodiment, the time constant of the first-order lag filter H(s) is preferably set individually for each of the d-axis component, q-axis component, and f-axis component, but is not necessarily limited thereto, and the same time constant may be used for each axis component.

[0092] As described above, the embodiments of the present invention have been described. However, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Description of Reference Numerals

[0093] 10, Controller, 100, Motor control system, 101, Motor (wound field synchronous motor)

Claims

1. In a wound-field synchronous motor including a rotor having a rotor winding and a stator having a stator winding, a motor control method for controlling a stator current flowing through the stator winding and a rotor current flowing through the rotor, comprising: calculating a first d-axis voltage command value and a first q-axis voltage command value based on a d-axis current command value and a q-axis current command value with respect to the stator current, respectively, and calculating a first f-axis voltage command value based on an f-axis current command value with respect to the rotor current; calculating an interference voltage not only between the d-axis and the q-axis of the stator current but also an interference voltage between the d-axis and the q-axis and the f-axis of the rotor current based on the d-axis current command value, the q-axis current command value, the f-axis current command value, and a rotational state of the motor, and calculating a non-interference voltage for non-interfering the interference voltage; correcting the first d-axis voltage command value, the first q-axis voltage command value, and the first f-axis voltage command value using a d-axis component, a q-axis component, and an f-axis component of the non-interference voltage, respectively, to calculate a second d-axis voltage command value, a second q-axis voltage command value, and a second f-axis voltage command value; calculating estimated values of a d-axis disturbance voltage, a q-axis disturbance voltage, and an f-axis disturbance voltage based on a final d-axis voltage command value and a final q-axis voltage command value for the stator, a final f-axis voltage command value for the rotor, the stator current, and the rotor current; correcting the second d-axis voltage command value, the second q-axis voltage command value, and the second f-axis voltage command value using the estimated values of the d-axis disturbance voltage, the q-axis disturbance voltage, and the f-axis disturbance voltage to calculate the final d-axis voltage command value, the final q-axis voltage command value, and the final f-axis voltage command value; controlling the stator current based on the calculated final d-axis voltage command value and the final q-axis voltage command value, and controlling the rotor current based on the final f-axis voltage command value; A motor control method.

2. The motor control method according to claim 1, wherein the estimated values of the d-axis disturbance voltage, the q-axis disturbance voltage, and the f-axis disturbance voltage are calculated based on an inverse system of a transfer function representing a transfer characteristic from a voltage to a current of the motor, the transfer function includes interference components between the d-axis component, the q-axis component, and the f-axis component; A motor control method.

3. The motor control method according to claim 2, wherein the transfer function is set based on a rotational state parameter of the motor, the rotational state parameter uses a detection value by a sensor. Motor control method.

4. The motor control method according to claim 2 or 3, applying a first-order lag filter and an inverse system of the transfer function to the stator current and the rotor current, where the difference between the denominator order and the numerator order is greater than or equal to the difference between the denominator order and the numerator order of the transfer function, to calculate a first d-axis voltage estimated value, a first q-axis voltage estimated value, and a first f-axis voltage estimated value; applying the first-order lag filter to the final d-axis voltage command value, the final q-axis voltage command value, and the final f-axis voltage command value to calculate a second d-axis voltage estimated value, a second q-axis voltage estimated value, and a second f-axis voltage estimated value; calculating estimated values of the d-axis disturbance voltage, the q-axis disturbance voltage, and the f-axis disturbance voltage by subtracting the first d-axis voltage estimated value, the first q-axis voltage estimated value, and the first f-axis voltage estimated value from the second d-axis voltage estimated value, the second q-axis voltage estimated value, and the second f-axis voltage estimated value; Motor control method.

5. The motor control method according to claim 4, wherein the time constant of the first-order lag filter is individually set for each of the d-axis component, the q-axis component, and the f-axis component, and the time constant of the first-order lag filter for the f-axis component is set to be larger than the time constants of the first-order lag filter for the d-axis component and the q-axis component. Motor control method.

6. A motor control device for controlling a wound-field synchronous motor including a rotor having a rotor winding and a stator having a stator winding, comprising a controller that controls a stator current flowing through the stator winding and a rotor current flowing through the rotor, wherein the controller calculates a first d-axis voltage command value and a first q-axis voltage command value based on a d-axis current command value and a q-axis current command value for the stator current, respectively, and calculates a first f-axis voltage command value based on an f-axis current command value for the rotor current, and calculates an interference voltage not only between the d-axis and the q-axis of the stator current but also between the d-axis and the q-axis and the f-axis of the rotor current based on the d-axis current command value, the q-axis current command value, the f-axis current command value, and the rotational state of the motor, to cancel the interference voltage. By correcting the first d-axis voltage command value, the first q-axis voltage command value, and the first f-axis voltage command value, respectively, using the d-axis component of the non-interference voltage, the q-axis component of the non-interference voltage, and the f-axis component of the non-interference voltage, a second d-axis voltage command value, a second q-axis voltage command value, and a second f-axis voltage command value are calculated. Based on the final d-axis voltage command value and the final q-axis voltage command value for the stator, the final f-axis voltage command value for the rotor, the stator current, and the rotor current, estimated values of the d-axis disturbance voltage, the q-axis disturbance voltage, and the f-axis disturbance voltage are calculated. The second d-axis voltage command value, the second q-axis voltage command value, and the second f-axis voltage command value are corrected using the estimated values of the d-axis disturbance voltage, the q-axis disturbance voltage, and the f-axis disturbance voltage to calculate the final d-axis voltage command value, the final q-axis voltage command value, and the final f-axis voltage command value. The stator current is controlled based on the calculated final d-axis voltage command value and the final q-axis voltage command value, and the rotor current is controlled based on the final f-axis voltage command value. Motor control device.

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