JP2018057159A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve smooth mode transition according to a change in load during acceleration.SOLUTION: In a motor controller 10, a drive control part controls, in a load detection section, a motor driving part on the basis of a predetermined δ-axis voltage in a γ-δ coordination system and a predetermined command angular velocity. A load detection part detects a load on a motor in the load detection section. The drive control part controls, in an acceleration section, the motor driving part to drive the motor while changing the characteristics of the δ-axis voltage increasing with the lapse of time according to the load detected by the load detection part.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a motor control device.

  For example, when a permanent magnet synchronous motor (hereinafter referred to as a motor) is driven sensorlessly using an induced voltage (hereinafter referred to as a position detection operation), in order to start the motor from a stop when no induced voltage is detected, A method is known in which a VF value that is a product of a voltage at which a motor can be started and a starting rotational speed is determined in advance, and the motor is forcibly commutated in accordance with the VF value. According to this method, in order to avoid the start failure due to insufficient torque, it is conceivable to set the VF value at the start in accordance with the magnitude of the load. In this case, the motor is started in an excessive voltage state (overvoltage state).

  However, when the voltage is excessive, a large current is generated on the d-axis of the motor due to the surplus power, resulting in the result that the rotor of the motor advances more than the optimum position (for example, the position where the efficiency is maximum). In this state, when switching from acceleration operation (operation by forced commutation) to normal operation (position detection operation) (hereinafter referred to as mode transition), the advance amount is too large (that is, the control axis (Because the phase difference between the [gamma]-[delta] axis) and the dq axis is large), the motor may stop due to step-out.

  Therefore, when the motor is started, the phase adjustment operation (operation that adjusts the phase difference by performing the acceleration operation at an angular velocity such that the γ-axis current Iγ becomes zero) is performed between the acceleration operation and the position detection operation. A method has been proposed (see, for example, Patent Document 1). According to Patent Document 1, a smooth mode transition can be realized by performing the phase adjustment operation.

JP2013-207868A

  However, in the above-described prior art, for example, a blower fan used in an outdoor unit of an air conditioner is a load having a large moment of inertia, and the load is increased by an external force such as wind or rain water drops during acceleration operation at the time of startup. In a motor that drives a load that may vary in size, a sufficient number of rotations may not be obtained at startup and position detection operation using an induced voltage may not be possible.

  The present invention has been made in view of the above-described prior art, and is a motor control device capable of realizing a smooth mode transition corresponding to a load change even when the load fluctuates during acceleration operation. The purpose is to provide.

  In order to solve the above-described problems and achieve the object, a motor control device according to one aspect of the present invention includes a drive unit that drives a motor and a current detection unit that detects a current of the motor. It is. The motor control device includes a load detection unit that detects a load of the motor, and a predetermined δ-axis voltage and a predetermined command angular velocity in the γ-δ coordinate system in a load detection section from the start of the motor to the first time. And driving the motor to drive the motor based on the δ-axis voltage and the commanded angular velocity that increase with time in the acceleration operation section from the first time to the second time. And a control unit. The load detection unit detects a load of the motor in the load detection section, and the drive control unit determines a characteristic of the δ-axis voltage that increases with time in the acceleration operation section according to the load detected by the load detection unit. The drive unit is controlled so as to drive the motor.

  The motor control device according to the present invention has an effect that, for example, smooth mode transition can be realized in response to load fluctuation during acceleration operation.

FIG. 1 is a diagram illustrating a relationship among a UVW fixed coordinate system, a γ-δ coordinate system, and a dq coordinate system in the embodiment. FIG. 2 is a diagram illustrating a voltage vector and a current vector in a steady state of motor rotation in the embodiment. FIG. 3 is a diagram illustrating a voltage vector and a current vector in an excessive voltage state of motor rotation in the embodiment. FIG. 4 is a diagram illustrating a setting example of the command voltage and the command angular velocity during the acceleration operation in the embodiment. FIG. 5 is a diagram illustrating changes in the δ-axis voltage, the command angular velocity, and the evaluation current at the time of startup in the embodiment. FIG. 6 is a diagram illustrating a voltage vector and a current vector when the motor load is increased in the embodiment. FIG. 7 is a diagram illustrating a configuration of the motor control device according to the embodiment. FIG. 8 is a diagram illustrating a configuration of a speed estimation processor according to the embodiment. FIG. 9 is a flowchart showing the start-up operation process according to the embodiment.

  Below, an example of an embodiment of a motor control device concerning the present invention is described in detail based on a drawing. In the following embodiments, a load in which the load torque (moment) is large and the load torque fluctuates irregularly due to an external force such as wind or raindrops, such as a blower fan (eg, a propeller fan) of an outdoor unit of an air conditioner. An example is a motor control device that controls a sensorless synchronous motor (hereinafter referred to as a motor) that drives the motor by position sensorless vector control. However, the present invention is widely applicable to a motor control device that controls a compressor motor.

  In addition, embodiment shown below does not limit this invention. In addition, the following embodiments and modifications thereof can be combined as appropriate within a consistent range. In addition, the following embodiment mainly shows the configuration and processing according to the present invention, and the description of the other configuration and processing is simplified or omitted. Moreover, in each embodiment, the same code | symbol is provided to the same structure and process, and description of an existing structure and process is abbreviate | omitted.

[Embodiment]
First, an outline of the embodiment will be described.

(Definition of coordinate system)
FIG. 1 is a diagram illustrating a relationship among a UVW fixed coordinate system, a γ-δ coordinate system, and a dq coordinate system in the embodiment. The d-axis and q-axis represent coordinate axes of a two-phase rotational coordinate system, and Id, Iq, Vd, and Vq are current and voltage on the d-axis and q-axis, respectively. In the d-axis, the direction of the magnetic pole N of the rotor in the motor is positive, and the axis orthogonal to the d-axis in the rotation direction of the rotor is the q-axis. A control axis (γ-δ axis) corresponding to the dq axis is a γ-δ axis, and a rotation angle from the α axis (U phase) to the γ axis is θe. During normal operation of the motor that detects the position of the rotor, the control axis (γ−δ axis) coincides with the dq axis, so the phase difference between the α axis and the d axis is θe. On the other hand, since the position of the rotor is not detected when the motor is started, the position of the d-axis is unknown. Therefore, the phase difference between the α axis and the γ axis is θe, and the phase difference between the γ axis and the d axis is Δθ. The rotor rotates counterclockwise at an angular velocity ωe. The rotation angle θe indicates the current position of the rotor.

(Voltage vector and current vector in ideal state of motor rotation)
FIG. 2 shows a voltage vector and a current vector in a state where the magnet torque is maximum when the motor rotates in the embodiment, that is, a state where the magnet torque can be most generated with the current value (the induced voltage vector φ · ωe matches the current vector). FIG. When the motor is rotating with the maximum magnet torque, the voltage-current equation is expressed by the following equations (1-1) and (1-2). However, in the following formulas (1-1) and (1-2), it is assumed that the control axis (γ-δ axis) coincides with the dq axis, that is, the motor is rotating in an ideal state. ing. Therefore, the γ-δ axis coincides with the dq axis, and d and q are used as subscripts for variables.

  In the above equations (1-1) and (1-2), R is the winding resistance value, Ld is the winding inductance viewed from the d axis, Lq is the winding inductance viewed from the q axis, and φ is the rotor The magnetic flux Eox is an expansion induced voltage.

  If the magnet torque is considered to be dominant over the reluctance torque when the motor is started, and only the magnet torque is used for the start, the d-axis current Id may be controlled to zero. Therefore, when Id = 0 is substituted into the above equations (1-1) and (1-2), the following equations (2-1) and (2-2) are obtained. When the d-axis current Id is 0, the induced voltage Eox generated in the steady state is 0 due to the inductance difference. Therefore, in the following equation (2-2), the angular velocity ωe of the rotor and the magnetic flux φ Expressed as a product. FIG. 2 is a diagram showing the ideal state indicated by the following equations (2-1) and (2-2) as a vector.

(Voltage vector and current vector in excessive motor rotation voltage state)
FIG. 3 is a diagram illustrating a voltage vector and a current vector in an excessive voltage state of motor rotation in the embodiment. In order to avoid starting failure due to insufficient torque, when the motor is rotating in an excessive voltage state, the control axis (γ-δ axis) rotates with a phase difference Δθ from the dq axis with a delayed phase. . Assuming that the γ-δ axis is steadily rotating and the transient term is 0, the relational expression of voltage and current on the control axis (γ-δ axis) is expressed by the following equations (3-1) and (3-2). ) Expression. FIG. 3 is a diagram representing the excessive voltage state indicated by the following equations (3-1) and (3-2) as a vector.

  In the excessive voltage state shown in FIG. 3, when the mode is shifted directly from acceleration operation (operation by forced commutation) without position detection feedback to normal operation (position detection operation), the phase deviates from the ideal state by a phase difference Δθ. Therefore, the motor control device performs correction control so as to eliminate this phase difference. During this correction control, the larger the phase difference Δθ, the more current hunting occurs with the correction control. In the worst case, the start-up may fail due to step-out. Therefore, it is considered that the switching shock accompanying the mode transition can be mitigated by bringing the excessive voltage state shown in FIG. 3 closer to the ideal state shown in FIG. Is provided with a phase adjustment processing section.

  Therefore, focusing on the γ-axis current Iγ projected onto the γ-axis, the γ-axis current Iγ is positively generated in the excessive voltage state of FIG. 3, and the d-axis current Id projected onto the d-axis is also positive (first In the quadrant). Compared with FIG. 2, in the phase adjustment process, when the d-axis current Id is finally controlled to be 0, the γ-axis voltage shown in the above equation (3-1) is the above equation (2-1). It is thought that it approaches the d-axis voltage shown in FIG.

  Therefore, first, the γ-axis voltage Vsγ * during acceleration operation is defined as shown in the following equation (4) using the angular velocity ωse * and the detected δ-axis current Iδ of the motor. This is obtained by replacing the voltage Vd, the d-axis current Id, and the angular velocity ωe in the equation (2-1) with the γ-axis voltage Vsγ *, the δ-axis current Iδ, and the angular velocity ωse *, respectively.

  The angular velocity ωse * is the rotational speed at which forced commutation is performed at the time of startup, and is a value designed in advance by a preliminary test or the like. Even if there is a load variation corresponding to a δ-axis voltage Vsδ * described later. It is an angular velocity that can be sufficiently synchronously drawn (the motor moves from the stop state to the continuous rotation state). The angular velocity ωse * and the voltage Vsδ * are parameters for performing forced commutation, and may be temporally variable by VF control or the like (for example, an acceleration operation in which the angular velocity ωse * and the δ-axis voltage Vsδ * are increased with time). May be a constant value. In any case, the motor to be driven is set to a value capable of accelerating to a preset rotational speed.

  Then, the phase is adjusted by adjusting either the voltage or the angular velocity in order to bring the phase state of FIG. 3 closer to the ideal state of FIG. 2, that is, the phase difference Δθ = 0. However, if the γ-axis voltage has already been adjusted by the above equation (4) and the γ-axis voltage and the δ-axis voltage are adjusted at the same time, there is a possibility of causing mutual control and divergence of control. Further, since the δ-axis voltage generates a δ-axis current for generating torque, if it is excessively reduced, the step-out may occur due to insufficient torque, so that a large adjustment range cannot be taken.

  Therefore, an existing method is used in which the δ-axis voltage is a constant voltage and the angular velocity of the control axis (γ-δ axis) is adjusted so that the current applied voltage and the load torque are balanced (see Patent Document 1). In the case of an excessive voltage state, the γ-axis current Iγ appears positive as shown in FIG. 3, and the projected d-axis current is also positive. At this time, since the control axis (γ-δ axis) is retarded by Δθ with respect to the dq axis, if the angular velocity of the control axis (γ-δ axis) is accelerated, the phase difference Δθ decreases. I will do it. Conversely, when the γ-axis current is a negative value, control is performed so as to reduce the angular velocity of the control axis (γ-δ axis). That is, by controlling the angular velocity of the control axis (γ-δ axis) so that the γ-axis current becomes zero, the phase converges to an ideal state with respect to the current voltage and load.

  As described above, during the acceleration operation (forced commutation), the δ-axis voltage Vsδ * and the γ-axis voltage Vsγ * are generated. The δ-axis voltage Vsδ * is given as a constant or a variable value that changes with time. Further, the γ-axis voltage Vsγ * is sequentially calculated and updated using the detected δ-axis current Iδ, with the initial value set to 0 based on the above equation (4). Forced commutation is performed while the γ-axis voltage Vsγ * is updated, the angular velocity becomes sufficiently high, and the motor is accelerated until a stable synchronous operation state is reached. Detection of the stable synchronous operation state of the motor is determined, for example, based on the passage of a predetermined time. As shown in FIGS. 2 and 3, the applied voltage V is desirably in the second quadrant on the control axis (γ-δ axis), but the γ-axis voltage Vsγ * is not necessarily given by the above equation (4). There is no need to be done. For example, Vsγ * may be zero.

(Example of setting command voltage and command angular velocity during acceleration operation)
FIG. 4 is a diagram illustrating a setting example of the command voltage and the command angular velocity during the acceleration operation in the embodiment. FIG. 4 is a diagram illustrating the δ-axis voltage Vsδ * and the command angular velocity ωse * in the acceleration operation and the phase adjustment process performed before the phase adjustment process. In FIG. 4, an offset voltage Vδof is a voltage Vsδ * applied at the start of acceleration operation, and a transition voltage Vδsf corresponds to a voltage Vsδ * immediately before transitioning to phase adjustment processing. In FIG. 4, the offset angular velocity ωof is the angular velocity ωse * at the start of acceleration operation, and the transition angular velocity ωsf is the angular velocity ωse * immediately before the transition to the phase adjustment process. The acceleration operation section is a time from time t = 0 to time t = T when the phase adjustment process is started.

  In the following, a start-up method by acceleration operation that forcibly shifts to phase adjustment processing when the acceleration operation time T elapses will be described. In starting the motor, the offset voltage Vδof, the transition voltage Vδsf, the offset angular velocity ωof, the transition angular velocity ωsf, and the acceleration operation time T are parameters set in advance by a preliminary test or the like. Among these parameters, the offset voltage Vδof and the offset angular velocity ωof are values that can sufficiently start rotation of the load connected to the motor.

  Further, the transition voltage Vδsf and the transition angular velocity ωsf are set to values corresponding to normal operation. For example, if the normal operation detects the induced voltage and performs the rotor position detection operation, it is necessary to set the transition angular velocity and the transition voltage that can generate the induced voltage sufficiently when switching to the normal operation. There is. However, since the phase adjustment processing is the existing method described above, that is, a method of varying the angular velocity with respect to the applied voltage, when starting with excessive voltage, the rotation speed is faster than the transition angular velocity set at the time of mode transition. In many cases, the transition voltage and the transition angular velocity must be determined in consideration of the speed increase.

  Also, the control function of the δ-axis voltage and the command angular velocity from the offset voltage Vδof and the offset angular velocity ωof to the transition voltage Vδsf and the transition angular velocity ωsf is a time function that increases with the passage of time, and is a linear function that can be controlled with a proportional coefficient Apply. The function of the δ-axis voltage and the command angular velocity is not limited to a linear function, and may be other functions such as an exponential function or a quadratic function.

  The control equation for the δ-axis voltage Vsδ * is as shown in the following equation (5-1), and the control equation for the angular velocity ωse * is as shown in the following equation (5-2). However, t in the following formulas (5-1) and (5-2) is a variable representing the time after the elapse of time, and assumes a value between 0 and T. Note that αV in the following equation (5-1) and αω in the following equation (5-2) are proportional coefficients.

  The motor control device starts output at the offset voltage Vδof and the offset angular velocity ωof at the start of start-up, and thereafter counts the elapsed time with a built-in timer and follows δ according to the above equations (5-1) and (5-2). The shaft voltage and command angular velocity are changed. The γ-axis voltage Vsγ * is calculated based on the above equation (4) from the angular velocity ωse * calculated by the above equation (5-2) and the detected δ-axis current Iδ. When the built-in timer counts T, the motor controller shifts to the phase adjustment process using the transition voltage Vδsf, transition angular velocity ωsf at that time, and the γ-axis voltage Vsγ * calculated based on the above equation (4) as initial values. To do.

(Changes in voltage, angular velocity, and current at startup)
FIG. 5 is a diagram illustrating changes in the δ-axis voltage, the command angular velocity, and the evaluation current at the time of startup in the embodiment. FIG. 5 shows the starting characteristics when a load detection section is added to FIG. Hereinafter, an example of expanding the startable range when the load fluctuation is larger than expected will be described. As described above, the transition voltage Vδsf and the transition angular velocity ωsf may be determined in advance in consideration of load fluctuations. However, an excessive margin setting in consideration of rare and unexpected load fluctuations may be activated. This is undesirable from the viewpoint of power consumption.

  Therefore, in normal times, activation is performed in accordance with a predetermined δ-axis voltage and a command angular velocity, and when the magnitude of the load increases due to some factor, the transition voltage is increased to V1 in accordance with the increment of the load. For this purpose, a load detection section for detecting an increase in load is provided in front of the acceleration operation section.

  As shown in FIG. 5, before and after the acceleration operation according to the above equations (5-1) and (5-2), increase / decrease in load is detected in the load detection section. In FIG. 5, the load detection section is the time from time t = 0 until the end after the calculation of the evaluation current I <b> 1 described later. In the load detection section, the offset voltage Vδof and the offset angular velocity ωof are output at a constant value for a certain time. At this time, the γ-axis voltage is a variable voltage calculated by the above equation (4) in the load detection section. Note that the γ-axis voltage is not necessarily a variable voltage calculated by the equation (4). For example, it may be zero.

  In FIG. 5, the change of the δ-axis voltage Vsδ * when starting in a normal load state is indicated by a solid line. At this time, Vsδ * in the acceleration operation section and the phase adjustment processing section has the same characteristics as in FIG. Further, the reference current corresponding to the case where the offset voltage Vδof is started is expressed as I0. The reference current I0 is a current value corresponding to a reference load that is a reference, and is calculated in advance from an actual measurement value using the following equation (6) as a representative value of the load. The time required for load detection in the load detection section is at least the time (for example, several seconds) until the calculation of the formula (4) and the formula (6) is completed.

  Further, the evaluation current I1 shown in FIG. 5 is obtained by detecting n (n = 0, 1,...) Discretely detected by N samplings after the motor operation is stabilized (a preset time has elapsed) in the load detection section. ... (N-1) When the γ-axis current is Iγ (n) and the δ-axis current is Iδ (n), the calculation is performed by the following equation (6). In the following formula (6), N is the number of samples. Sampling is started after a predetermined time has elapsed from the start of load activation. This is because it takes a predetermined time for the rotation to stabilize and the current value to settle.

  4 and 5, when the phase converges in the phase adjustment processing section, the mode transition to the normal operation is performed, and the transition timing is whether or not a predetermined time has elapsed since the start of the phase adjustment process, or The determination is made based on whether or not the amount of decrease in the amplitude value of the motor current to be controlled has reached a predetermined amount.

  In FIG. 5, when the magnitude of the load increases or decreases, only the voltage characteristic is changed, and the characteristic of the commanded angular velocity is fixed. This is because when the inertia moment of the load is constant and the magnitude of the load changes, stable startup can be secured by changing the voltage while fixing the characteristics of the commanded angular velocity.

  However, the command angular velocity characteristic is not limited to a fixed value by changing only the voltage characteristic, and the command angular velocity may be variablely controlled together with the voltage characteristic.

(Voltage vector and current vector when the motor load increases)
FIG. 6 is a diagram illustrating a voltage vector and a current vector when the motor load is increased in the embodiment. FIG. 6 shows a case where the load of the motor is increased as compared with FIG. 3. The d axis at the time of load increase is d ₁ axis, the q axis is q ₁ axis, and the phase difference increases from Δθ to Δθ as the load increases. _The state is reduced to ₁ . In FIG. 6, only the δ-axis voltage Vδ is the same as that in FIG. 3, and other currents and voltages change, so the subscript 1 is added.

  When the motor is started due to excessive voltage and the load is larger than the load reference, the advance angle of the rotor with respect to the control shaft is small (that is, the phase angle between the rotating magnetic field and the rotor is small). Therefore, it is considered that the control axis (γ-δ axis) approaches an ideal state where it coincides with the dq axis. Therefore, as shown in FIG. 6, since the q-axis current increases, that is, the surplus power on the d-axis side moves to the q-axis (torque axis) side, the power is consumed as torque and the motor efficiency is improved. Therefore, the current detected from the shunt resistor is reduced. This current is the evaluation current I1 shown in FIG. 6, and the evaluation current I1 is calculated by the above equation (6).

  Then, the evaluation current I1 and the reference current I0 are compared, and if the evaluation current I1 is smaller than the reference current I0 (see FIG. 5), it is determined that the load state has become heavy due to an external force such as wind. Here, if k = I0−I1, when the load becomes heavy due to an external force such as wind, k> 0, and the voltage proportionality coefficient αv1 is obtained from the following equation (7), and the above (5-1 The voltage Vsδ * is calculated by replacing the proportionality coefficient αv in the equation) with the proportionality coefficient αv1. In this way, the starting voltage can be increased as the load increases.

  In addition, when k <0 described above, it is determined that the load has decreased. However, if the voltage is decreased during synchronous activation, it may be considered that there is a risk of a step-out stop due to insufficient torque (for example, wind Such as weather conditions where the wind blows intermittently or the wind direction changes frequently). In this case, when light load (k <0) is detected, k = 0 may be set in the above equation (7). In this case, αv1 = αv, and the voltage characteristics do not change. That is, it is desirable that the voltage is higher from the viewpoint of safety of starting. Therefore, it is preferable that the voltage characteristic is corrected only when the load becomes large, and the voltage correction is not performed when the load becomes light.

  However, even if the above-mentioned k = I0−I1 is expanded to a negative value, the above equation (7) and the following equation (9) are satisfied, and therefore, it is possible to cope with the deceleration direction of the estimated command angular velocity. The correction is not limited to the case where k = I0−I1 ≧ 0.

  Note that k described above may be a ratio instead of a difference. For example, if k = I0 / I1, the above equation (7) is replaced with the following equation (8). In this case, when k> 1, the voltage proportional coefficient αv1 is obtained from the following equation (8), and the proportional coefficient αv in the above equation (5-1) is replaced with the proportional coefficient αv1 to calculate the voltage Vsδ *. . In the case of k <1, if k = 1, the voltage increase at light load can be zero. Similarly, even if the above-mentioned k = I0 / I1 is expanded to a value smaller than 1, the following formulas (8) and (9) are satisfied, so that it is possible to deal with the deceleration direction of each estimated command speed. Therefore, the voltage correction is not limited to the case of k = I0 / I1 ≧ 1.

  The control equation for the corrected δ-axis voltage Vsδ * shown in the following equation (9) is obtained by replacing αv in the equation (5-1) with the proportional coefficient αv1 obtained as described above.

  In this way, the motor connected to the load undergoes load detection, acceleration operation, and phase adjustment in the load detection section included in the start-up, the acceleration operation section that follows the load detection section, and the phase adjustment processing section that follows the acceleration operation section. Transition to normal operation.

(Configuration of motor controller)
FIG. 7 is a diagram illustrating a configuration of the motor control device according to the embodiment. FIG. 8 is a diagram illustrating a configuration of a speed estimation processor according to the embodiment. A motor M is connected to the motor control device 10 according to the embodiment. The motor controller 10 includes a subtractor 11, a speed controller 12, an excitation current controller 13, a subtractor 14, a subtractor 15, a d-axis current controller 16, a q-axis current controller 17, a non-interacting processor 18, γ-axis voltage output processor 19, δ-axis voltage output processor 20, first switch 21, second switch 22, dq / UVW converter 23, PWM (Pulse Width Modulation) generator 23, IPM (Intelligent Power Module) 24 1 shunt resistor 26, current regenerator 27, UVW / dq converter 28, synchronous rotation speed output processor 29, speed estimator 30, integrator 32, load detector 33, shaft error detection And a speed estimator 34, a divider 35, and a controller 36.

  Although not shown, the control unit 36 is connected to the first switch 21, the second switch 22, and the third switch 31, and switches the connection state of each switch according to the time counted by the control unit 36. The control unit 36 also controls the γ-axis voltage output processor 19, the δ-axis voltage output processor 20, the synchronous rotation speed output processor 29, and the speed estimator 30.

  The subtractor 11 is an actual speed (mechanical angle actual speed) ωm that is an estimated current angular speed output from the divider 35 from a speed command value (command rotational speed) ωm * input to the motor control device 10. Is output to the speed controller 12.

The speed controller 12 generates a q-axis current command value Iq * such that the speed deviation Δω output from the subtractor 11 is small, and outputs it to the subtractor 14. The excitation current controller 13 generates a d-axis current command value Id ^* from the q-axis current command value Iq ^* output from the speed controller 12 and outputs the d-axis current command value Id ^* to the subtracter 15.

  Since speed controller 12 is connected to a PI controller (not shown), the integrator holds q-axis current command value Iq *. Therefore, when the mode is shifted to the normal operation, that is, when the switch 31 is switched from the terminal 2 to the terminal 1, the integrator is initialized with the δ-axis current command value Iδ * generated immediately before the mode shift.

  The subtractor 14 subtracts the q-axis current Iq (Iδ) output from the UVW / dq converter 28 from the q-axis current command value Iq * output from the speed controller 12 to generate a q-axis current deviation ΔIq. And output to the q-axis current controller 17. The subtracter 15 subtracts the d-axis current Id (Iγ) output from the UVW / dq converter 28 from the d-axis current command value Id * to generate a d-axis current deviation ΔId, and sends it to the d-axis current controller 16. Output.

  The d-axis current controller 16 generates a d-axis voltage command value Vda * from the d-axis current deviation ΔId output from the subtracter 15. The q-axis current controller 17 generates a q-axis voltage command value Vqa * from the q-axis current deviation ΔIq output from the subtractor 14.

  The non-interacting processor 18 generates a non-interacting correction value for canceling interference between the d-axis voltage command value Vda * and the q-axis voltage command value Vqa * and controlling each independently, Are used to generate a d-axis voltage command value Vd * and a q-axis voltage command value Vq * obtained by correcting the d-axis voltage command value Vda * and the q-axis voltage command value Vqa *, respectively. The non-interacting processor 18 outputs the d-axis voltage command value Vd * and the q-axis voltage command value Vq * to the axis error detection and speed estimator 34.

  Further, the non-interacting processor 18 performs the first operation in order to shift to the normal operation after a predetermined time sufficient for the speed estimation to be completed has elapsed in the phase adjustment processing section. When connected to the dq / UVW converter 23 via the switch 21 and the second switch 22, the d-axis voltage command value Vd * and the q-axis voltage command value Vq * are output to the dq / UVW converter 23.

  The d-axis current controller 16 and the q-axis current controller 17 operate in cooperation with the non-interacting processor 18. The following formulas (10-1) and (10-2) are obtained by calculating the d-axis voltage command value Vda * and the q-axis voltage command value Vqa * and the d-axis voltage command value Vd * and the q-axis voltage command value Vq *. Show the relationship.

  Here, φ in the above equation (10-2) is the amount of magnetic flux of the rotor of the motor M. The second term on the right side of the equation (10-1) is an interference correction term for the d-axis voltage, and the second term on the right side of the equation (10-2) is an interference correction term for the q-axis voltage. The non-interacting processor 18 performs calculations based on the above equations (10-1) and (10-2), and generates a d-axis voltage command value Vd * and a q-axis voltage command value Vq *.

  Therefore, the d-axis voltage controller 16 holds the d-axis voltage command value Vda *. The q-axis current controller 17 holds the q-axis voltage command value Vqa *. Immediately before the first switch 21 and the second switch 22 are switched to connect the non-interacting processor 18 and the dq / UVW converter 23 during the mode transition to the normal operation, the γ-axis voltage output processor 19 Γ-axis voltage Vsγ * is output, and the δ-axis voltage output processor 20 outputs the δ-axis voltage Vsδ *. These γ-axis voltage Vsγ * and δ-axis voltage Vsδ * correspond to the d-axis voltage command value Vd * in the equation (10-1) and the q-axis voltage command value Vq * in the equation (10-2).

  As a result, at the time of transition to normal operation, the γ-axis voltage output processor 19 was outputting just before the first switch 21 was switched to connect the non-interacting processor 18 and the dq / UVW converter 23. Since the γ-axis voltage Vsγ * is equal to the second term on the right side of the above equation (10-1), the control unit 36 initializes the d-axis voltage command value Vda * held by the d-axis current controller 16 with zero. Further, at the time of transition to normal operation, the control unit 36 sets the q-axis voltage command value Vqa * held by the q-axis current controller 17 to Vsδ * on the left side of the above equation (10-2), Vsδ *, Initialization may be performed with Vsδ * −ωe · (Ld · Iγ + φ) calculated by replacing Id in the second term with Iγ.

  The γ-axis voltage output processor 19 is connected to the dq / UVW converter 23 via the first switch 21 in the load detection interval and the acceleration operation interval, and to the synchronous rotation speed output processor 29 via the third switch 31. If connected, the γ-axis voltage Vsγ * is calculated from the angular velocity ωse * output from the synchronous rotation speed output processor 29 and the detected current δ-axis current Iδ from the above equation (4), and dq / Output to UVW converter 23. The γ-axis voltage Vsγ * is updated from the initial value 0 as the motor M accelerates, gradually increases to the negative side, and eventually converges to a constant value.

  The δ-axis voltage output processor 20 converts a constant voltage Vsδ * (= Vδof) to dq / UVW conversion when connected to the dq / UVW converter 23 via the second switch 22 in the load detection section. Output to the device 23.

  The δ-axis voltage output processor 20 is calculated based on the above equation (5-1) when connected to the dq / UVW converter 23 via the second switch 22 in the acceleration operation section. The output voltage Vsδ * is output to the dq / UVW converter 23. The voltage Vsδ * increases from the offset voltage Vδof as a starting point according to the above equation (5-1) using αV calculated by the load detector 33. Since the δ-axis voltage Vsδ * calculated based on the above equation (5-1) varies depending on the value of αV output from the load detector 33, an appropriate value corresponding to the load is used. .

  Further, the δ-axis voltage output processor 20 holds the voltage Vsδ * (= Vδsf) immediately before calculated from the above equation (5-1) immediately before the transition from the acceleration operation period to the phase adjustment process period. To do. Then, the δ-axis voltage output processor 20 outputs the transition voltage Vδsf to the dq / UVW converter 23 via the second switch 22 in the phase adjustment processing section.

  In the first switch 21, the common contact 210 is connected to one of the contact 1 and the contact 2 by the control unit 36. The first switch 21 outputs the d-axis voltage command value Vd * output from the non-interacting processor 18 to the dq / UVW converter 23 in a state where the contact 1 is connected to the common contact 210. Further, the first switch 21 outputs the γ-axis voltage Vsγ * output from the γ-axis voltage output processor 19 to the dq / UVW converter 23 when the contact 2 is connected to the common contact 210.

  In the second switch 22, the common contact 220 is connected to one of the contact 1 and the contact 2 by the control unit 36. The second switch 22 outputs the d-axis voltage command value Vd * output from the non-interacting processor 18 to the dq / UVW converter 23 when the contact 1 is connected to the common contact 220. In addition, the second switch 22 outputs the δ-axis voltage Vsδ * (= Vδof) output from the δ-axis voltage output processor 20 to the dq / UVW converter 23 when the contact 2 is connected to the common contact 220. To do.

  The dq / UVW converter 23 uses the rotation angle θe output from the integrator 32 to convert the non-interfering two-phase d-axis voltage command value Vd * and q-axis voltage command value Vq * into three-phase. Conversion into a U-phase output voltage command value Vu *, a V-phase output voltage command value Vv *, and a W-phase output voltage command value Vw *. Then, the dq / UVW converter 23 outputs the U-phase output voltage command value Vu *, the V-phase output voltage command value Vv *, and the W-phase output voltage command value Vw * to the PWM generator 24.

  Here, the rotational angle θe output from the integrator 32 is the angular velocity output from the synchronous rotational speed output processor 29 when the integrator 32 is connected to the synchronous rotational speed output processor 29 by the third switch 31. This is the current rotor position based on ωse *. In addition, the rotation angle θe output from the integrator 32 is equal to the estimated angular velocity ωse ′ output from the speed estimator 30 when the integrator 32 is connected to the speed estimator 30 by the third switch 31. Based on the current rotor position. The rotation angle θe output from the integrator 32 is output from the axis error detection / speed estimator 34 when the integrator 32 is connected to the axis error detection / speed estimator 34 by the third switch 31. , The current rotor position based on the estimated angular velocity ωe.

  Note that Vu *, Vv *, and Vw * and Iu, Iv, and Iw described later are voltages and currents in a three-phase fixed coordinate system.

  The PWM generator 24 calculates a PWM drive signal (U, V, W, X) from the U-phase output voltage command value Vu *, the V-phase output voltage command value Vv *, the W-phase output voltage command value Vw *, and the PWM carrier signal. , Y, Z) are generated and output to the IPM 25.

  The IPM 25 is a DC voltage supplied from the outside, based on the 6-phase PWM drive signal output from the PWM generator 24, to apply to the U phase, V phase, and W phase of the motor M. Vdc is chopped and generated, and the AC voltage of each phase is applied to the U phase, V phase, and W phase of the motor M.

  The current regenerator 27 calculates the U-phase current Iu and V-phase current Iv of the motor M from the 6-phase PWM switching information output from the PWM generator 24 and the bus current detected by the shunt resistor 26 using the one-shunt current detection method. W phase current Iw is calculated. The current detection method is a 2CT method in which a U-phase current Iu and a V-phase current Iv are detected by two CTs (Current Transformers), and the remaining W-phase current Iw is calculated from a relational expression of Iu + Iv + Iw = 0. Also good. The current regenerator 27 outputs the calculated U phase current Iu, V phase current Iv, and W phase current Iw of the motor M to the UVW / dq converter 28.

  The UVW / dq converter 28 uses the rotation angle θe output from the integrator 32 to convert the three-phase U-phase current Iu, V-phase current Iv, and W-phase current Iw output from the current regenerator 27 to 2 Phase d-axis current Id and q-axis current Iq are converted. The UVW / dq converter 28 subtracts the d-axis current Id from the subtractor 15, the speed estimator 30, the load detector 33, the axis error detection / speed estimator 34, and the q-axis current Iq from the subtractor 14. The voltage is output to the voltage output processor 19 and the load detector 33, respectively. The d-axis current Id input to the speed estimator 30, the load detector 33, the axis error detection and speed estimator 34 is replaced with the γ-axis current Iγ of the control axis (γ-δ axis), and the γ-axis voltage is substituted. The q-axis current Iq input to the output processor 19 and the load detector 33 is substituted with the δ-axis current Iδ of the control axis (γ-δ axis).

  When the synchronous rotation speed output processor 29 is connected to the integrator 32 via the third switch 31 in the load detection section, the constant rotational speed of the angular velocity ωse * (= ωof) is sent to the integrator 32. Output. The rotation angle θe in the load detection section is generated by time-integrating the angular velocity ωse * (= ωof) by the integrator 32. The rotation angle θe in the load detection section is a phase angle (see FIG. 1) between the α axis (U phase axis) and the γ axis in the load detection section. The dq / UVW converter 23 converts the rotation coordinate system of the γ-δ orthogonal axis into a UVW three-phase fixed coordinate system using the rotation angle θe in the load detection section.

  The synchronous rotation speed output processor 29 is calculated based on the above equation (5-2) when it is in the acceleration operation section and is connected to the integrator 32 via the third switch 31. The angular velocity ωse * is output to the integrator 32. The synchronous rotation speed output processor 29 starts the offset angular velocity ωof as a starting point and increases the angular velocity ωse * for synchronization according to the above equation (5-2).

  The rotation angle θe in the acceleration operation section is generated by time-integrating the angular velocity ωse * by the integrator 32. The rotation angle θe in the acceleration operation section is a phase angle (see FIG. 1) between the α axis (U phase axis) and the γ axis in the acceleration operation section. The dq / UVW converter 23 converts the rotation coordinate system of the γ-δ orthogonal axis into the UVW three-phase fixed coordinate system using the rotation angle θe in the acceleration operation section.

  As shown in FIG. 8, the speed estimator 30 includes a coefficient unit 30-1 having an integral constant KI, a coefficient unit 30-2 having a proportional constant KP, an integrator 30-3, and an adder 30-4. The motor enters the phase adjustment section after a predetermined time has elapsed since entering the acceleration operation section. In the phase adjustment section, the speed estimator 30 estimates the angular speed ωse ′ that makes the γ-axis current zero and approaches the maximum magnet torque state.

  That is, the speed estimator 30 receives the γ-axis current Iγ as an input in the phase adjustment processing section, and sets the integration constant KI and the proportionality constant KP for the γ-axis current Iγ by the coefficient unit 30-1 and the coefficient unit 30-2, respectively. Multiplying the output of the coefficient multiplier 30-1 by the integrator 30-3 and adding the output of the integrator 30-3 and the output of the coefficient multiplier 30-2 by the adder 30-4 Are sequentially estimated and output.

  Note that the rotation angle θe in the phase adjustment processing section is generated by time-integrating the angular velocity ωse ′ by the integrator 32. The rotation angle θe in the phase adjustment processing section is a phase angle (see FIG. 1) between the α axis (U phase axis) and the γ axis in the phase adjustment processing section. In the phase adjustment processing section, the dq / UVW converter 23 converts the rotation coordinate system of the γ-δ orthogonal axes into the UVW three-phase fixed coordinate system using the rotation angle θe.

  Here, the integral constant KI and the proportional constant KP are determined in advance so that the estimated angular velocity ωse ′ converges. Further, the speed estimator 30 needs to be initialized at the angular speed immediately before being connected to the integrator 32 via the third switch 31 when the acceleration operation section is shifted to the phase adjustment processing section. For example, according to the above equation (5-2), the initial value is the transition angular velocity ωsf. The transition angular velocity ωsf is an angular velocity at the transition to the phase adjustment processing section.

  When a predetermined time that can be considered that the rotation of the motor M is stable in the load detection period has elapsed during the load detection period, the load detector 33 performs the γ-axis current Iγ and the δ-axis current based on the above equation (6). From the value of k described above based on the reference current I0 calculated from Iδ and the evaluation current I1, the proportionality coefficient αv1 is obtained by the above expression (7) or (8), and the proportionality coefficient αV is output to the δ-axis voltage output processor 20. To do. In the load detection section, the calculation of the above equation (6) may be repeated for a predetermined time, or the value of the sampling number N is determined in advance and the number of times is counted until the sampling number N is reached. Then, sampling may be performed.

  The axis error detection / speed estimator 34 includes the d-axis current Id (Iγ) and the q-axis current Iq (Iδ) output from the UVW / dq converter 28 and the d-axis voltage output from the non-interacting processor 18. From the command value Vd * and the q-axis voltage command value Vq *, the induced voltage of the motor M is estimated, and further the current angular velocity ωe is estimated. The axis error detection and speed estimator 34 outputs the estimated current angular speed ωe to the divider 35.

  Further, the axis error detection and speed estimator 34 integrates via the third switch 31 in order to shift to normal operation after a predetermined time sufficient for completing the speed estimation in the phase adjustment processing section. When connected to the integrator 32, the estimated angular velocity ωe is output to the integrator 32. The angular velocity ωe estimated by the axis error detection and speed estimator 34 becomes a rotation angle θe for coordinate conversion by integration control by the integrator 32 and is also used for speed control by the speed controller 12.

  Since the axis error detection and speed estimator 34 maintains the angular speed ωe, when connected to the integrator 32 via the third switch 31 during the mode transition from the acceleration operation to the normal operation, the control unit 36 Initializes the angular velocity held by the axis error detection and velocity estimator 34 with the angular velocity ωse ′ estimated immediately before by the velocity estimator 30.

  The divider 35 divides the estimated current angular velocity ωe output from the axis error detection and speed estimator 34 by the pole pair number Pn of the motor M, converts it to an actual speed (mechanical angular actual speed) ωm, and outputs it. To do.

  As described above, each integration of the speed controller 12, which is a PI controller, the d-axis current controller 16, the q-axis current controller 17, the axis error detection and the speed estimator 34, when shifting from the acceleration operation to the normal operation. If the device is initialized and the mode is changed, the phase has already been adjusted by the speed estimator 30, so that the operation is smoothly continued before and after the switching. During normal operation, the motor M has the first switch 21 and the second switch 22 connected to the non-interacting processor 18 side, and the third switch 31 connected to the axis error detection and speed estimator 34 side. The speed is controlled by the formed feedback loop and driven by the speed command value ωm *.

  The dq / UVW converter 23, the PWM generator 24, and the IPM 25 are an example of a drive unit that drives a motor. The shunt resistor 26 and the current regenerator 27 are an example of a current detection unit that detects a motor current. The load detector 33 is an example of a load detection unit that detects a motor load in the load detection section. Further, the γ-axis voltage output processor 19, the δ-axis voltage output processor 20, and the synchronous rotation speed output processor 29 are predetermined in the γ-δ coordinate system in the load detection section from the start of the motor to the first time. Driving the motor on the basis of the first variable γ-axis voltage in the γ-δ coordinate system corresponding to the predetermined command angular velocity and the δ-axis current of the motor, In the acceleration operation section from the time to the second time, based on the δ-axis voltage and the command angular velocity that increase with time, and the second variable γ-axis voltage according to the command angular velocity and the δ-axis current of the motor. If there is a difference between the load detected by the load detector and the reference load, the characteristic of the δ-axis voltage that increases with time in the acceleration operation section is changed according to the load. Drive to control the drive unit to drive It is an example of a control unit. The speed estimator 30 is an example of an estimation unit that estimates an angular velocity at which the γ-axis current is zero among the γ-axis current and the δ-axis current in the γ-δ coordinate system of the motor detected by the current detection unit.

(Start-up operation processing)
FIG. 9 is a flowchart showing the start-up operation process according to the embodiment. The start operation process is a load detection process in the load detection section, an acceleration operation process in the acceleration operation section, which is sequentially executed in the motor control device 10 from the start of the start of the motor M (see FIG. 7) to the normal operation. Includes phase adjustment processing in the phase adjustment processing section.

  First, the control unit 36 performs switch switching (step S11). The control unit 36 connects the common contact 210 and the contact 2 of the first switch 21 (see FIG. 7), connects the common contact 220 and the contact 2 of the second switch 22 (see FIG. 7), and connects the third switch. 31 (see FIG. 7) common contact 310 and contact 3 are connected. As a result, in the motor control device 10, the angular speed ωse * is output from the synchronous rotation speed output processor 29 (see FIG. 7) to the integrator 32. The angular velocity ωse * is integrated by the integrator 32 to generate the rotation angle θe. Next, the rotation angle θe is input to the dq / UVW converter 23 and the UVW / dq converter 28 (step S11).

  Next, the control part 36 starts a load detection process (step S12). The control unit 36 sets the output of the γ-axis voltage output processor 19 as the γ-axis voltage Vsγ * = 0, the output of the δ-axis voltage output processor 20 as the δ-axis voltage Vsδ * = Vsof, and the output of the synchronous rotation speed output processor 29. Are initialized as angular velocity ωse * = ωof, respectively (step S12).

  Next, the control unit 36 maintains the constant output of the voltage Vsδ * = Vsof in the δ-axis voltage output processor 20 and the constant output of the angular speed ωse * = ωof in the synchronous rotational speed output processor 29, while maintaining the γ-axis voltage output. The processor 19 updates and outputs the γ-axis voltage Vsγ * by the above equation (4). And the control part 36 determines whether rotation of the motor M was stabilized (for example, predetermined time passed, after performing step S12) (step S13). When it is determined that the rotation of the motor M is stable (step S13: Yes), the control unit 36 moves the process to step S14.

  In step S14, the control unit 36 causes the load detector 33 to execute load detection. The controller 36 continues from step S12, while maintaining the δ-axis voltage output processor 20 to maintain a constant output of voltage Vsδ * = Vsof and the synchronous rotation speed output processor 29 to maintain a constant output of angular velocity ωse * = ωof, the γ-axis The voltage output processor 19 updates and outputs the γ-axis voltage Vsγ * by the above equation (4).

  The control unit 36 calculates the evaluation current I1 based on the above equation (6), and when the above k = I0−I1 based on the reference current I0 and the evaluation current I1 is k> 0, the above (7) Load detection for determining the proportionality coefficient αv1 from the equation is executed by the load detector 33 and output to the δ-axis voltage output processor 20 (step S14). Even when k = I0−I1 is k ≦ 0, the proportionality coefficient αv1 may be determined by the above equation (7). However, for stabilization, k = 0 is good.

  Note that k described above may be a ratio instead of a difference. If k = I0 / I1 is defined, in step S14, when k = I0 / I1 is k> 1, load detection for determining the proportionality coefficient αv1 by the above equation (8) is executed, and the δ-axis voltage output is performed. The data is output to the processor 20. Note that, even when k = I0 / I1 is k ≦ 1, the proportionality coefficient αv1 may be determined. However, for stabilization, k = 1 is preferable so that αv1 = αv.

  Next, the control unit 36 determines whether or not the load detector 33 has completed the load detection by performing the calculation according to the above equation (6) (step S15). When the control unit 36 receives the load detection completion signal from the load detector 33 and determines that the load detector 33 has completed the load detection (step S15: Yes), the control unit 36 moves the process to step S16, and the load detector 33 If it is determined that the load detection is not completed (step S15: No), the process returns to step S14.

  In step S16, the control unit 36 starts an acceleration operation process. In the acceleration operation process, the control unit 36 causes the γ-axis voltage output processor 19 to continuously output the γ-axis voltage Vsγ *, while the output of the δ-axis voltage output processor 20 is synchronized with the δ-axis voltage Vsδ * = Vδof. The output of the rotation speed output processor 29 is initialized to an angular velocity ωse * = ωof.

  Next, the control unit 36 accelerates the rotor (step S17). The control unit 36 continues to update the γ-axis voltage Vsγ * by the γ-axis voltage output processor 19 from step S16 and output the γ-axis voltage Vsγ * according to the above-described equation (4), while allowing the δ-axis voltage output processor 20 to Based on the above (5-2), the angular velocity ωse * is calculated and output based on the above (5-2) (step S17). Each time step S17 is executed, the value of t to be substituted into the above equations (9) and (5-2) is t = 0 when the execution of step S16 is started. Is the elapsed time.

  Next, the controller 36 determines whether or not a predetermined time (acceleration operation time) T has elapsed since step S16 was executed (step S18). The predetermined time varies depending on the device to which the present invention is applied, but is about several seconds to about 10 seconds. When the control unit 36 starts executing step S16 and determines that the predetermined time T has elapsed (step S18: Yes), the control unit 36 proceeds to step S19 and determines that the predetermined time T has not elapsed ( Step S18: No), the process is returned to step S17.

  In step S19, the control unit 36 initializes the initial value of the integrator 30-3 of the speed estimator 30 with the transition angular speed ωsf.

  Next, the control part 36 performs switch switching (step S20). The control unit 36 connects the common contact 310 and the contact 2 of the third switch 31. Thereby, in the motor control device 10, the angular velocity ωse ′ output from the speed estimator 30 (see FIG. 7) is integrated and controlled by the integrator 32 to generate the rotation angle θe. The generated rotation angle θe is input to the dq / UVW converter 23 and the UVW / dq converter 28.

  Next, the control part 36 starts a phase adjustment process (step S21). The control unit 36 causes the γ-axis voltage output processor 19 to continuously output the γ-axis voltage Vsγ * last updated in step S19 according to the equation (4), while causing the δ-axis voltage output processor 20 to ) If the δ-axis voltage Vsδ * (αv1) given by t = T in the equation (7) is given by the above equation (7), then the δ-axis voltage Vsδ * = Vδof + (1 + k / I0) · αv · T, αv1 , The constant voltage of δ-axis voltage Vsδ * = Vδof + k · αv · T is continuously output (step S23).

  Next, the control unit 36 performs a phase adjustment process (step S22). From step S21, the control unit 36 continues to update the γ-axis voltage output processor 19 to update and output the γ-axis voltage Vsγ * by the above equation (4), and finally updates the δ-axis voltage output processor 20 in step S19. While the voltage Vsδ * is continuously output, the speed estimator 30 estimates and outputs the angular speed ωse ′ (step S24).

  Next, the control unit 36 determines whether or not a predetermined estimated time sufficient for completing the phase adjustment processing after executing Step S20 has elapsed (Step S23). The predetermined time varies depending on the apparatus to which the present invention is applied, but is about several seconds. If the controller 36 determines that a predetermined estimated time sufficient to complete the speed estimation has elapsed since the execution of step S22 (step S23: Yes), the process proceeds to step S24, and the predetermined predetermined time is sufficient. If it is determined that the estimated time has not elapsed (step S23: No), the process returns to step S22.

  In step S <b> 24, the control unit 36 performs an initialization process as a stage before the transition from the phase adjustment process to the normal operation. The control unit 36 (1) initializes the initial value of the integrator of the axis error detection and speed estimator 34 with the angular velocity ωse ′ estimated immediately before by the speed estimator 30, and (2) sets the speed controller 12 to (3) The d-axis current controller 16 is initialized with Vsγ * −ωe · Lq · Iδ, and (4) the q-axis current controller 17 is set with Vsδ * + ωe · Initialize with (Ld · Iγ + φ).

  Next, the control part 36 performs switch switching (step S25). The control unit 36 connects the common contact 210 and the contact 1 of the first switch 21, connects the common contact 220 and the contact 1 of the second switch 22, and connects the common contact 310 and the contact 1 of the third switch 31. Connect (step S25). Then, the motor control device 10 completes the mode transition from the phase adjustment process to the normal operation (step S26).

  Steps S12 to S15 described above correspond to the load detection process, steps S16 to S18 correspond to the acceleration operation process, and steps S21 to S23 correspond to the phase adjustment process.

  In a general startup method using accelerated operation, the risk of step-out in mode transition is inevitable unless the load state is strictly estimated and voltage characteristics and command angular velocity characteristics are reset. This is because the estimation of the load state includes a certain amount of error, and the adjustment of the applied voltage and the angular velocity in the mode transition requires considerable strictness. However, in the embodiment, load detection is performed before the mode transition, and phase adjustment processing is performed after acceleration operation is performed with voltage characteristics corresponding to the load. Therefore, even if the voltage characteristic deviates from the true value and becomes excessive, it can be converged to an appropriate phase angle by the phase adjustment processing. That is, strictness is not required for the load detection before the mode transition, and the load fluctuation range that can be activated can be set extremely wide. In the embodiment in which the start characteristic is varied by monitoring the load state, a wider and more appropriate motor control can be performed by performing the phase adjustment process before the mode transition.

  The specific names, processes, controls, and information including various data and parameters in the above-described embodiment and illustration are merely examples, and can be changed as appropriate unless otherwise specified. In addition, the configuration of each unit or each device in the above-described embodiment may be appropriately distributed or integrated from the processing load, mounting efficiency, and the like.

  The broader aspects of the embodiments described above are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the general inventive concept or scope defined by the appended claims and their equivalents.

M motor 10 motor controller 11 subtractor 12 speed controller 14 subtractor 15 subtracter 16 d-axis current controller 17 q-axis current controller 18 non-interacting processor 19 γ-axis voltage output processor 20 δ-axis voltage output process Device 21 first switch 210 common contact 22 second switch 220 common contact 23 dq / UVW converter 24 PWM generator 25 IPM
26 Shunt resistor 27 Current regenerator 28 UVW / dq converter 29 Synchronous rotation speed output processor 30 Speed estimator 30-1 Coefficient unit 30-2 Coefficient unit 30-3 Integrator 30-4 Adder 31 Third switch 310 Common Contact 32 Integrator 33 Load detector 34 Axis error detection and speed estimator 35 Divider 36 Controller

Claims (5)

A motor control device having a drive unit for driving a motor and a current detection unit for detecting a current of the motor,
A load detector for detecting the load of the motor;
In the load detection section from the start of the motor to the first time, the motor is driven based on a predetermined δ-axis voltage and a predetermined command angular velocity in the γ-δ coordinate system, and from the first time to the first time. A driving control unit that controls the driving unit to drive the motor based on a δ-axis voltage and a commanded angular velocity that increase with time in the acceleration operation section up to the time of 2,
The load detection unit detects a load of the motor in the load detection section,
In the acceleration operation section, the drive control unit changes the characteristic of the δ-axis voltage that increases with the passage of time according to the load detected by the load detection unit so as to drive the motor. The motor control device characterized by controlling a part. In the acceleration operation section, when the load detected by the load detection unit is larger than a predetermined reference load, the drive control unit increases the δ-axis voltage that increases over time with a high increase rate. When the load detected by the load detector is equal to or less than a predetermined reference load, the characteristic of the δ-axis voltage that increases with the passage of time is not changed. The motor control device according to claim 1. The motor control device according to claim 1, wherein the load detection unit detects a load of the motor based on a current of the motor detected by the current detection unit. The load detection unit detects the load of the motor based on a difference or ratio between a current of the motor detected by the current detection unit and a reference current predetermined corresponding to the reference load. The motor control device according to claim 3, wherein An estimator for estimating an angular velocity at which the γ-axis current is zero among the γ-axis current and the δ-axis current in the γ-δ coordinate system of the motor detected by the current detector;
In the phase adjustment section from the second time to the third time, the drive control unit is configured to use the current detection unit based on a rotation angle obtained by integrating and controlling the angular velocity estimated by the estimation unit. The γ-axis current and the δ-axis voltage corresponding to the γ-axis current and the δ-axis current of the motor detected by the γ-δ coordinate system are the voltages in the fixed coordinate system when the motor is driven by the driving unit. The motor control device according to claim 1, wherein the motor control device is converted into a motor control device.

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