JP6787006B2 - Motor control device - Google Patents

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 (hereinafter referred to as a position detection operation) using an induced voltage, the motor is started from a stop when the induced voltage is not detected. A method is known in which a VF value, which is the product of a voltage at which a motor can be started and a starting rotation speed, is determined in advance, and forced commutation of the motor is performed according to 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 time of start according to the magnitude of the load. In this case, the motor will start in a state of excessive voltage (state of overvoltage).

However, when the voltage is excessive, a large current is generated on the d-axis of the motor due to the surplus power, so that the rotor of the motor advances more than the optimum position (for example, the position where the efficiency is maximized). 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 amount of advance angle is too large (that is, the control shaft). (Because the phase difference between the γ-δ axis and the dq axis is large), the motor may stop due to step-out.

Therefore, when the motor is started, a phase adjustment operation (operation for adjusting the phase difference by performing 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, smooth mode transition can be realized by performing the phase adjustment operation.

Japanese Unexamined Patent Publication No. 2013-207868

However, in the above-mentioned conventional technique, for example, like a blower fan used in an outdoor unit of an air conditioner, the load has a large moment of inertia and is loaded by an external force such as wind or rain water drops during accelerated operation at startup. In a motor that drives a load that may fluctuate in magnitude, a sufficient rotation speed may not be obtained at the time of starting, and position detection operation using an induced voltage may not be possible.

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

In order to solve the above-mentioned problems and achieve the object, the motor control device according to one aspect of the present invention is a motor control device having a drive unit for driving the motor and a current detection unit for detecting the current of the motor. Is. The motor control device also has a load detection unit that detects the load of the motor and a predetermined δ-axis voltage and a predetermined command angular velocity in the γ-δ coordinate system in the load detection section from the start of the motor to the first time. In the acceleration operation section from the first time to the second time, the drive unit is controlled so as to drive the motor based on the δ-axis voltage and the command angular velocity that increase with the passage of time. It is equipped with a control unit. The load detection unit detects the load of the motor in the load detection section, and the drive control unit determines the characteristic of the delta-axis voltage that increases with the passage of 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, a smooth mode transition can be realized in response to load fluctuations during accelerated operation.

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

An example of an embodiment of the motor control device according to the present invention will be described in detail below with reference to the drawings. In the following embodiment, a load such as a blower fan (for example, a propeller fan) of an outdoor unit of an air conditioner, which has a large load torque (moment) and whose load torque fluctuates irregularly due to an external force such as wind or rainy water drops. 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 can be widely applied to a motor control device for controlling a compressor motor and the like.

The embodiments shown below do not limit the present invention. In addition, the embodiments and modifications thereof shown below can be appropriately combined within a consistent range. In addition, the embodiments shown below mainly show the configuration and processing according to the present invention, and the description of other configurations and processing will be simplified or omitted. Further, in each embodiment, the same reference numerals are given to the same configurations and processes, and the description of the existing configurations and processes will be omitted.

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

(Definition of coordinate system)
FIG. 1 is a diagram showing the relationship between the UVW fixed coordinate system, the γ-δ coordinate system, and the dq coordinate system in the embodiment. The d-axis and q-axis represent the coordinate axes of the two-phase rotating coordinate system, and Id, Iq and Vd, and Vq are currents and voltages on the d-axis and q-axis, respectively. For 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. The control axis (γ-δ axis) corresponding to the dq axis is defined as the γ-δ axis, and the 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, when the motor is started, the position of the rotor is not detected, so 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 of ωe. The rotation angle θe indicates the current position of the rotor.

(Ideal state voltage vector and current vector for motor rotation)
FIG. 2 shows the voltage vector and the current vector in the state where the magnet torque is maximum when the motor is rotating in the embodiment, that is, the state where the magnet torque can be obtained most at the current current value (the induced voltage vectors φ · ωe and the current vector match). It is a figure which shows. When the motor is rotating with the maximum magnet torque, the voltage-current equations are expressed by the following equations (1-1) and (1-2). However, in the following equations (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 the ideal state. ing. Therefore, the γ-δ axis and the dq axis coincide with each other, and d and q are used as the subscripts of the variables.

In the above equations (1-1) and (1-2), R is the winding resistance value, Ld is the winding inductance seen from the d-axis, Lq is the winding inductance seen from the q-axis, and φ is the rotor. The magnetic flux of, Ex, is the extended induced voltage.

When starting the motor, it is considered that the magnet torque is dominant over the reluctance torque, and if only the magnet torque is used for starting, the d-axis current Id may be controlled to 0. 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 generated by the inductance difference is 0 for the extended induced voltage Ex in the steady state. Therefore, in the following equation (2-2), the angular velocity ωe of the rotor and the magnetic flux φ are It is represented by a product. FIG. 2 is a vector representation of the ideal states represented by the following equations (2-1) and (2-2).

(Voltage vector and current vector in the overvoltage state of motor rotation)
FIG. 3 is a diagram showing a voltage vector and a current vector in a state of excessive voltage of motor rotation in the embodiment. In order to avoid start failure due to insufficient torque, when the motor is rotating in an excessive voltage state, the control axis (γ-δ axis) will rotate with a phase difference Δθ behind the dq axis. .. Assuming that the γ-δ axis is constantly rotating and the transient term is 0, the relational expression between the voltage and the current on the control axis (γ-δ axis) is the following equations (3-1) and (3-2). ) Is expressed by the formula. FIG. 3 is a vector representation of the overvoltage state represented by the following equations (3-1) and (3-2).

When the mode is directly shifted from the accelerated operation (operation by forced commutation) without position detection feedback to the normal operation (position detection operation) in the excessive voltage state shown in FIG. 3, the phase deviates from the ideal state by the phase difference Δθ. Therefore, the motor control device performs correction control so as to eliminate this phase difference. In this correction control, the larger the phase difference Δθ, the more current hunting occurs due to the correction control, and in the worst case, step-out may cause a start failure. Therefore, it is considered that the switching shock associated with the mode transition can be alleviated by bringing the excessive voltage state shown in FIG. 3 closer to the ideal state shown in FIG. 2, and therefore, between the accelerated operation section and the normal operation section. Is provided with a phase adjustment processing section.

Therefore, focusing on the γ-axis current Iγ projected on the γ-axis, the γ-axis current Iγ is positively generated in the overvoltage state of FIG. 3, and the d-axis current Id projected on the d-axis is also positive (first). Appears 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) becomes the above equation (2-1). It is considered that the voltage approaches the d-axis voltage shown in.

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

The angular velocity ωse * is the number of revolutions at which forced commutation is performed at startup, and is a value pre-designed by a preliminary test or the like, and corresponds to the δ-axis voltage Vsδ * described later, even if there is a load fluctuation. It is an angular velocity that can be sufficiently synchronously pulled in (the motor shifts from the stopped state to the continuous rotation state). The angular velocity ωse * and the voltage Vsδ * are parameters for forced commutation, and may be time-variable by VF control or the like (for example, acceleration operation in which the angular velocity ωse * and the δ-axis voltage Vsδ * are increased over time). However, it may be a constant value. In any case, the value is set so that the motor or the like to be driven can be accelerated to a preset rotation speed.

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

Therefore, the δ-axis voltage is set to a constant voltage, and an existing method of adjusting the angular velocity of the control axis (γ-δ-axis) is used so that the current applied voltage and the load torque are in equilibrium (see Patent Document 1). In the case of excessive voltage, the γ-axis current Iγ appears positively as shown in FIG. 3, and the projected d-axis current also becomes positive. At this time, the control axis (γ-δ axis) is retarded by Δθ with respect to the dq axis, so if the angular velocity of the control axis (γ-δ axis) is accelerated, the phase difference Δθ decreases. I will continue. On the contrary, when the γ-axis current is a negative value, the angular velocity of the control axis (γ-δ-axis) is controlled to be decelerated. That is, by controlling the angular velocity of the control axis (γ-δ axis) so that the γ-axis current becomes 0, the phase converges to the ideal state with respect to the current voltage and load.

As described above, during the accelerated operation (forced commutation), the δ-axis voltage Vsδ * and the γ-axis voltage Vsγ * are generated. The delta-axis voltage Vsδ * is given as a constant or a variable value that changes over time. Further, the γ-axis voltage Vsγ * is sequentially calculated and updated using the detected δ-axis current Iδ of the motor 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, and the motor is accelerated until the angular velocity becomes sufficiently high and a stable synchronous operation state is reached. The detection of the stable synchronous operation state of the motor is determined, for example, by the lapse of a predetermined time. As shown in FIGS. 2 and 3, it is desirable that the applied voltage V is 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). You don't have to be. For example, Vsγ * may be set to zero.

(Example of setting command voltage and command angular velocity during acceleration operation)
FIG. 4 is a diagram showing a setting example of a command voltage and a command angular velocity during acceleration operation in the embodiment. FIG. 4 is a diagram showing 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, the offset voltage Vδof is the voltage Vsδ * applied at the start of the acceleration operation, and the transition voltage Vδsf corresponds to the voltage Vsδ * immediately before the transition to the phase adjustment process. Further, in FIG. 4, the offset angular velocity ωof is the angular velocity ωse * at the start of the accelerated operation, and the transition angular velocity ωsf is the angular velocity ωse * immediately before shifting to the phase adjustment process. The acceleration operation section is the time from the time t = 0 to the time t = T at which the phase adjustment process is started.

In the following, a start method by acceleration operation forcibly shifting to the phase adjustment process when the acceleration operation time T elapses will be described. When starting the motor, the offset voltage Vδof, the shift voltage Vδsf, the offset angular velocity ωof, the shift angular velocity ωsf, and the acceleration operation time T are parameters preset by a preliminary test or the like. Of these parameters, the offset voltage Vδof and the offset angular velocity ωof are values that allow the load connected to the motor to start rotating sufficiently.

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 is a method in which the induced voltage is detected and the rotor position is detected, it is necessary to set the transition angular velocity and the transition voltage so that the induced voltage can be sufficiently generated when the normal operation is switched to. There is. However, since the phase adjustment processing is the above-mentioned existing method, that is, a method of changing the angular velocity with respect to the applied voltage, when the engine is started with an excessive voltage, the rotation speed becomes faster than the transition angular velocity set at the time of mode transition. Since there are many cases, the transition voltage and the transition angular velocity must be determined in consideration of this acceleration.

Further, the control functions 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 are linear functions that can be controlled by a proportional coefficient as a time function that increases with the passage of time. To apply. The δ-axis voltage and command angular velocity functions are not limited to linear functions, but may be other functions such as exponential functions and quadratic functions.

The control formula for the voltage Vsδ * on the δ axis is as shown in the following formula (5-1), and the control formula for the angular velocity ωse * is as shown in the following formula (5-2). However, t in the following equations (5-1) and (5-2) is a variable representing the time after the lapse of time, and is assumed to take a value between 0 and T. In addition, αV in the following formula (5-1) and αω in the following formula (5-2) are proportional coefficients.

The motor control device starts output at an offset voltage Vδof and an offset angular velocity ωof at the start of startup, and then δ according to the above equations (5-1) and (5-2) while counting the elapsed time with the built-in timer. The shaft voltage and the command angular velocity are changed. The γ-axis voltage Vsγ * is calculated from the angular velocity ωse * calculated by the above equation (5-2) and the detected δ-axis current Iδ based on the above equation (4). When the built-in timer counts T, the motor control device shifts to the phase adjustment process with the transition voltage Vδsf and the 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 showing changes in the delta-axis voltage, command angular velocity, and evaluation current at startup in the embodiment. FIG. 5 shows the start-up characteristics when the load detection section is added to FIG. The following is an example of expanding the startable range when the load fluctuation is larger than expected. As described above, the transition voltage Vδsf and the transition angular velocity ωsf may be set in advance in consideration of the load fluctuation, but an excessive margin setting in consideration of the rare large load fluctuation or the unexpected load fluctuation is started. Not desirable from the point of view of power consumption at the time.

Therefore, normally, the start is performed according to a predetermined δ-axis voltage and a command angular velocity, and when the magnitude of the load increases for some reason, the transition voltage is increased to V1 according to the increment of the load. For this purpose, a load detection section for detecting the load increment is provided before the acceleration operation section.

As shown in FIG. 5, the increase / decrease in the load is detected in the load detection section before the acceleration operation according to the above equations (5-1) and (5-2) is performed. In FIG. 5, the load detection section is the time until the time t = 0, and is the time from the start to the end of the calculation of the evaluation current I1 described later. In the load detection section, the offset voltage Vδof and the offset angular velocity ωof are output at constant values for a certain period of time. At this time, the γ-axis voltage is a variable voltage calculated by the above equation (4) in the load detection section. The γ-axis voltage does not necessarily have to be the variable voltage calculated by the equation (4). For example, it may be zero.

In FIG. 5, the change in the δ-axis voltage Vsδ * when the device is started under a normal load is shown by a solid line. At this time, Vsδ * in the acceleration operation section and the phase adjustment processing section has the same characteristics as those in FIG. Further, the reference current corresponding to the case of starting with the offset voltage Vδof is described as I0. The reference current I0 is a current value corresponding to a reference reference load, and is calculated in advance from the measured 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 calculations of the above equations (4) and (6) are completed.

Further, the evaluation current I1 shown in FIG. 5 is n (n = 0,1, ...) Discretely detected by sampling N pieces after the motor operation is stabilized in the load detection section (a preset time has elapsed).・ ・ Assuming that the N-1) th γ-axis current is Iγ (n) and the δ-axis current is Iδ (n), it is calculated by the following equation (6). In the following equation (6), N is the number of samples. Sampling is started after a predetermined time has elapsed from the start of load startup. This is because it takes a predetermined time for the rotation to stabilize and the current value to settle down.

In FIGS. 4 and 5, when the phase converges in the phase adjustment processing section, the mode shifts to the normal operation is performed, but the shift timing is whether or not a predetermined time has elapsed from the start of the phase adjustment processing, or Judgment 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 command angular velocity is fixed. This is because when the moment of inertia of the load is constant and the magnitude of the load changes, stable start-up can be ensured by fixing the characteristics of the command angular velocity and changing the voltage.

However, the characteristic of the command angular velocity is not limited to being fixed by changing only the voltage characteristic, and the command angular velocity may be variably controlled as well as the voltage characteristic.

(Voltage vector and current vector when the load of the motor increases)
FIG. 6 is a diagram showing a voltage vector and a current vector when the load of the motor is increased in the embodiment. 6, as compared with FIG. 3 shows the case where the load of the motor is increased, the d-axis when the load increases as d ₁ axis, [Delta] [theta] q-axis and q ₁ axis, the phase difference due to the load increase [Delta] [theta] _It shows a state of decrease to ₁ . In FIG. 6, only the δ-axis voltage Vδ is the same as in FIG. 3, and the 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 becomes 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 the ideal state that coincides with the dq axis. Therefore, as shown in FIG. 6, the q-axis current increases, that is, the surplus power on the d-axis side moves to the q-axis (torque shaft) side, so that 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 when the evaluation current I1 is smaller than the reference current I0 (see FIG. 5), it is determined that the load state has become heavier 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 proportional coefficient αv1 of the voltage is obtained from the following equation (7), and the above (5-1) ), The voltage Vsδ * is calculated by replacing the proportionality coefficient αv with the proportionality coefficient αv1. In this way, the starting voltage can be increased as the load increases.

Further, when k <0 described above, it is determined that the load has become smaller, but if the voltage is reduced at the time of synchronous start, it may be considered that there is a risk of step-out stop due to insufficient torque (for example, wind). (For example, in weather conditions where the wind blows intermittently or the wind direction changes frequently). In this case, when a light load (k <0) is detected, k = 0 in the above equation (7). In this case, αv1 = αv, and the voltage characteristics do not change. That is, since it is desirable that the voltage is higher from the viewpoint of starting safety, it is advisable to correct the voltage characteristics only when the load is large and not to perform the voltage correction when the load is light.

However, even if the above k = I0-I1 is extended to a negative value, the above equation (7) and the following equation (9) hold, so that the deceleration direction of the estimated command angular velocity can also be dealt with. The correction is not limited to the case where k = I0-I1 ≧ 0.

The above-mentioned k 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 proportional coefficient αv1 of the voltage 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 the time of light load can be set to 0. Similarly, even if the above k = I0 / I1 is extended to a value smaller than 1, the following equations (8) and (9) are satisfied, so that it is possible to correspond to the deceleration direction of each estimated command speed. Therefore, the voltage correction is not limited to the case where k = I0 / I1 ≧ 1.

The proportional coefficient αv1 obtained as described above replaces αv in the above equation (5-1), and becomes the controlled equation for the corrected δ-axis voltage Vsδ * shown in the following equation (9).

In this way, the motor to which the load is connected undergoes load detection, acceleration operation, and phase adjustment in each of the load detection section included at startup, the acceleration operation section following the load detection section, and the phase adjustment processing section following the acceleration operation section. , Shift to normal operation.

(Configuration of motor control device)
FIG. 7 is a diagram showing a configuration of a motor control device according to an embodiment. Further, FIG. 8 is a diagram showing 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 control device 10 includes a subtractor 11, a speed controller 12, an exciting current controller 13, a subtractor 14, a subtractor 15, a d-axis current controller 16, a q-axis current controller 17, and a decoupling 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 current detector shunt resistance 26, current regenerator 27, UVW / dq converter 28, synchronous rotation speed output processor 29, speed estimator 30, integrator 32, load detector 33, axis error detection It also has a speed estimator 34, a divider 35, and a control unit 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 measured by the control unit 36. Further, the control unit 36 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 estimated current angular velocity (mechanical angular velocity) ωm output from the divider 35 from the speed command value (command rotation speed) ωm * input to the motor control device 10. The speed deviation (mechanical angular velocity deviation) Δω obtained by subtracting the above is output to the speed controller 12.

The speed controller 12 generates a q-axis current command value Iq * so that the speed deviation Δω output from the subtractor 11 becomes small, and outputs the q-axis current command value Iq * to the subtractor 14. The exciting 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 subtractor 15.

Since the speed controller 12 is connected to a PI controller (not shown), the integrator holds the q-axis current command value Iq *. Therefore, when the mode shifts to the normal operation, that is, when the switch 31 switches 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 the q-axis current deviation ΔIq. Output to the q-axis current controller 17. The subtractor 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 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 subtractor 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-interference processor 18 cancels the interference between the d-axis voltage command value Vda * and the q-axis voltage command value Vqa *, generates a non-interference correction value for controlling each independently, and generates a non-interference correction value. The d-axis voltage command value Vda * and the q-axis voltage command value Vqa * are corrected by using, and the d-axis voltage command value Vd * and the q-axis voltage command value Vq * are generated. Then, the decoupling 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 decoupling transmitter 18 is first set in order to shift to the normal operation after a predetermined time sufficient for the speed estimation to be completed has elapsed in the time measured by the control unit 36 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-interfering processor 18. The following equations (10-1) and (10-2) are 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 above equation (10-1) is an interference correction term on the d-axis voltage, and the second term on the right side of the above equation (10-2) is an interference correction term on the q-axis voltage. The non-interfering processor 18 performs an operation based on the above equations (10-1) and (10-2) to generate a d-axis voltage command value Vd * and a q-axis voltage command value Vq *.

Therefore, the d-axis current controller 16 holds the d-axis voltage command value Vda *. Further, 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 at the time of mode transition to the normal operation are switched to connect the decoupling processor 18 and the dq / UVW converter 23, the γ-axis voltage output processor 19 The γ-axis voltage Vsγ * is output, and the δ-axis voltage Vsδ * is output from the δ-axis voltage output processor 20. These γ-axis voltage Vsγ * and δ-axis voltage Vsδ * correspond to the d-axis voltage command value Vd * in the above equation (10-1) and the q-axis voltage command value Vq * in the above equation (10-2).

From this, at the time of transition to normal operation, the γ-axis voltage output processor 19 was outputting immediately before the first switch 21 was switched to connect the decoupling 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 to 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 Vq * on the left side of the above equation (10-2) to Vsδ *, and sets the right side to Vsδ *. Initialization may be performed with Vsδ * -ωe · (Ld · Iγ + φ) calculated by replacing Id in the binomial 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 section and the acceleration operation section, and is connected to the synchronous rotation speed output processor 29 via the third switch 31. When 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.

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

Further, the δ-axis voltage output processor 20 is calculated based on the above equation (5-1) when it is connected to the dq / UVW converter 23 via the second switch 22 in the acceleration operation section. The voltage Vsδ * is output to the dq / UVW converter 23. The voltage Vsδ * starts from the offset voltage Vδof and increases the voltage 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) changes depending on the value of αV output from the load detector 33, an appropriate value according to the load is used. ..

Further, the δ-axis voltage output processor 20 holds the voltage Vsδ * (= Vδsf) immediately before the transition from the acceleration operation section to the phase adjustment processing section, which is calculated based on the above equation (5-1). 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 either the contact 1 or the contact 2 by the control unit 36. When the contact 1 is connected to the common contact 210, the first switch 21 outputs the d-axis voltage command value Vd * output from the non-interfering processor 18 to the dq / UVW converter 23. 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 in a state where the contact 2 is connected to the common contact 210.

In the second switch 22, the common contact 220 is connected to either the contact 1 or the contact 2 by the control unit 36. The second switch 22 outputs the d-axis voltage command value Vd * output from the non-interfering processor 18 to the dq / UVW converter 23 in a state where the contact 1 is connected to the common contact 220. Further, 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 generate a non-interfering two-phase d-axis voltage command value Vd * and a q-axis voltage command value Vq * in three phases. Converts to U-phase output voltage command value Vu *, V-phase output voltage command value Vv *, and 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 rotation angle θe output by the integrator 32 is the angular velocity output from the synchronous rotation speed output processor 29 in a state where the integrator 32 is connected to the synchronous rotation speed output processor 29 by the third switch 31. It is the current rotor position based on ωse *. Further, the rotation angle θe output by the integrator 32 is 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. Further, the rotation angle θe output by the integrator 32 is output from the axis error detection and speed estimator 34 when the integrator 32 is connected to the axis error detection and speed estimator 34 by the third switch 31. , The current rotor position based on the estimated angular velocity ωe.

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

The PWM generator 24 uses PWM drive signals (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) and output to IPM25.

Based on the 6-phase PWM drive signal output from the PWM generator 24, the IPM 25 applies a three-phase AC voltage applied to each of the U-phase, V-phase, and W-phase of the motor M to a DC voltage supplied from the outside. Vdc is generated by chopping, 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 uses the 6-phase PWM switching information output from the PWM generator 24 and the bus current detected by the shunt resistance 26 in the 1-shunt current detection method to generate the U-phase current Iu and the V-phase current Iv of the motor M. , W phase current Iw is calculated. The current detection method is a 2CT method in which U-phase current Iu and V-phase current Iv are detected by two CTs (Current Transformers), and the remaining W-phase current Iw is calculated from the relational expression of Iu + Iv + Iw = 0. May be 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 into two. It is converted into a phase d-axis current Id and a q-axis current Iq. Then, the UVW / dq converter 28 transfers the d-axis current Id to the subtractor 15, the speed estimator 30, the load detector 33, the axis error detection and the speed estimator 34, and the q-axis current Iq to the subtractor 14, the γ-axis. 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 the speed estimator 34 is replaced by the γ-axis current Iγ of the control axis (γ-δ-axis), and the γ-axis voltage is used. The q-axis current Iq input to the output processor 19 and the load detector 33 is replaced by 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 angular velocity of the angular velocity ωse * (= ωof) is transmitted to the integrator 32. Output. The rotation angle θe in the load detection section is generated by time-integrating the angular velocity ωse * (= ωof) with the integrator 32. The rotation angle θe in the load detection section is the 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 uses this rotation angle θe to convert the rotating coordinate system of the γ-δ orthogonal axis into the UVW three-phase fixed coordinate system in the load detection section.

Further, the synchronous rotation speed output processor 29 was calculated based on the above equation (5-2) when it was connected to the integrator 32 via the third switch 31 in the acceleration operation section. The angular velocity ωse * is output to the integrator 32. The synchronous rotation speed output processor 29 starts from the offset angular velocity ωof 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 * with the integrator 32. The rotation angle θe in the acceleration operation section is the 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 uses this rotation angle θe to convert the rotating coordinate system of the γ-δ orthogonal axis into the UVW three-phase fixed coordinate system in the acceleration operation section.

As shown in FIG. 8, the speed estimator 30 includes a coefficient device 30-1 having an integrator constant KI, a coefficient device 30-2 having a proportionality constant KP, an integrator 30-3, and an adder 30-4. The motor enters the phase adjustment section after a predetermined time has elapsed after entering the acceleration operation section. In the phase adjustment section, the velocity estimator 30 sets the γ-axis current to 0 and estimates the angular velocity ωse'that brings the magnet torque closer to the maximum state.

That is, the speed estimator 30 takes the γ-axis current Iγ as an input in the phase adjustment processing section, and sets the integrator KI and the proportional constant KP with respect to the γ-axis current Iγ by the coefficient device 30-1 and the coefficient device 30-2, respectively. Multiply, integrate the output of the coefficient device 30-1 with the integrator 30-3, and add the output of the integrator 30-3 and the output of the coefficient device 30-2 with the adder 30-4 to obtain the maximum magnet torque. The angular velocity ωse'is sequentially estimated and output.

The rotation angle θe in the phase adjustment processing section is generated by time-integrating the angular velocity ωse'with the integrator 32. The rotation angle θe in the phase adjustment processing section is the phase angle (see FIG. 1) between the α-axis (U-phase axis) and the γ-axis in the phase adjustment processing section. The dq / UVW converter 23 uses this rotation angle θe to perform coordinate conversion of the rotating coordinate system of the γ-δ orthogonal axis into the UVW three-phase fixed coordinate system in the phase adjustment processing section.

Here, the integration constant KI and the proportionality 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 velocity immediately before being connected to the integrator 32 via the third switch 31 at the time of transition from the acceleration operation section 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 the angular velocity at the time of transition to the phase adjustment processing section.

When the load detector 33 elapses a predetermined predetermined time during which the rotation of the motor M can be regarded as stable during the load detection period, the γ-axis current Iγ and the δ-axis current are based on the above equation (6). From the above-mentioned value of k based on the reference current I0 calculated from Iδ and the evaluation current I1, the proportional coefficient αv1 is obtained by the above equation (7) or (8), and the proportional coefficient αV is output to the δ-axis voltage output processor 20. To do. The calculation of the above equation (6) in the load detection section 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. And sampling may be performed.

The axis error detector and velocity estimator 34 uses the d-axis current Id (Iγ) and q-axis current Iq (Iδ) output from the UVW / dq converter 28 and the d-axis voltage output from the decoupling processor 18. The induced voltage of the motor M is estimated from the command value Vd * and the q-axis voltage command value Vq *, and the current angular velocity ωe is further estimated. The axis error detection and velocity estimator 34 outputs the estimated current angular velocity 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 has elapsed. When connected to the device 32, the estimated angular velocity ωe is output to the integrator 32. The angular velocity ωe estimated by the axis error detection and the velocity estimator 34 becomes the rotation angle θe for coordinate conversion by the integral control by the integrator 32, and is also used for the velocity control in the velocity controller 12.

Since the axis error detection and speed estimator 34 holds the angular velocity ωe, the control unit 36 is connected to the integrator 32 via the third switch 31 at the time of mode transition from accelerated operation to normal operation. 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 velocity estimator 34 by the pole logarithm Pn of the motor M, converts it to the actual velocity (mechanical angular velocity) ωm, and outputs it. To do.

As described above, at the time of transition from accelerated operation to normal operation, each integrator of the speed controller 12, the d-axis current controller 16, the q-axis current controller 17, the axis error detection and the speed estimator 34, which are PI controllers. 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 can be smoothly continued before and after the switching. Then, in the normal operation, in the motor M, the first switch 21 and the second switch 22 are connected to the decoupling processor 18 side, and the third switch 31 is 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 examples of a drive unit that drives the motor. Further, the shunt resistor 26 and the current regenerator 27 are examples of a current detection unit that detects the current of the motor. Further, the load detector 33 is an example of a load detection unit that detects the load of the motor in the load detection section. Further, the γ-axis voltage output processor 19, the δ-axis voltage output processor 20, and the synchronous rotation velocity output processor 29 are predetermined in the γ-δ coordinate system in the load detection section from the start of motor start to the first time. The motor is driven based on the δ-axis voltage and the predetermined command angular velocity of the above, and 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 accelerated operation section from the time of 1 to the second time, the δ-axis voltage and the command angular velocity that increase with the passage of time and the second variable γ-axis voltage according to the command angular velocity and the δ-axis current of the motor are used. If there is a difference between the load detected by the load detector and the reference load, the motor is driven by changing the characteristics of the δ-axis voltage, which increases with the passage of time, according to the load in the acceleration operation section. This is an example of a drive control unit that controls the drive unit so as to drive. Further, the speed estimator 30 is an example of an estimation unit that estimates the angular velocity at which the γ-axis current is set to 0 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.

(Startup operation process)
FIG. 9 is a flowchart showing the start-up operation process according to the embodiment. The start-up operation process includes load detection process in the load detection section and acceleration operation process in the acceleration operation section, which are 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 switches the switch (step S11). The control unit 36 connects the common contact 210 of the first switch 21 (see FIG. 7) and the contact 2, and connects the common contact 220 of the second switch 22 (see FIG. 7) and the contact 2, and connects the third switch. The common contact 310 of 31 (see FIG. 7) and the contact 3 are connected. As a result, in the motor control device 10, the angular velocity 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 angle of rotation 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 unit 36 starts the 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. Is initialized with the angular velocity ωse * = ωof (step S12).

Next, the control unit 36 outputs the γ-axis voltage while maintaining the constant output of the voltage Vsδ * = Vsof in the δ-axis voltage output processor 20 and the constant output of the angular velocity ωse * = ωof in the synchronous rotation speed output processor 29. The processor 19 updates the γ-axis voltage Vsγ * according to the above equation (4) and outputs the voltage. Then, the control unit 36 determines whether or not the rotation of the motor M is stable (for example, a predetermined time has elapsed since the execution of step S12) (step S13). When the control unit 36 determines that the rotation of the motor M is stable (step S13: Yes), the control unit 36 shifts the process to step S14.

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

The control unit 36 calculates the evaluation current I1 based on the above equation (6), and when the above-mentioned k = I0-I1 based on the reference current I0 and the evaluation current I1 is k> 0, the above (7) The load detector 33 is made to execute the load detection for determining the proportionality coefficient αv1 by the equation, and the δ-axis voltage output processor 20 is made to output (step S14). Even when the above-mentioned k = I0-I1 is k ≦ 0, the proportional coefficient αv1 may be determined by the above equation (7), but k = so that αv1 = αv for stabilization. It should be 0.

The above-mentioned k may be a ratio instead of a difference. According to the definition of k = I0 / I1, in step S14, when k = I0 / I1 is k> 1, load detection for determining the proportional coefficient αv1 is executed by the above equation (8), and the δ-axis voltage output is performed. Output to the processor 20. The proportional coefficient αv1 may be determined even when the above-mentioned k = I0 / I1 is k≤1, but k = 1 may be set so that αv1 = αv for stabilization.

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 shifts the process to step S16, and the load detector 33 moves. If it is determined that the load detection has not been completed (step S15: No), the process returns to step S14.

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

Next, the control unit 36 accelerates the rotor (step S17). The control unit 36 continuously updates the γ-axis voltage Vsγ * according to the above equation (4) and outputs the γ-axis voltage output processor 19 from step S16, while causing the δ-axis voltage output processor 20 to output the above equation (9). Based on this, the voltage Vsδ * on the δ axis is calculated and output, and the synchronous rotation speed output processor 29 calculates and outputs the angular velocity ωse * based on the above (5-2) (step S17). The value of t assigned to the above equations (9) and (5-2) each time the execution of step S17 is executed is t = 0 when the execution of step S16 is started, after the execution of step S16 is started. Is the elapsed time of.

Next, the control unit 36 determines whether or not a predetermined time (acceleration operation time) T has elapsed since the execution of step S16 (step S18). The predetermined time varies depending on the apparatus to which the present invention is applied, but is about several seconds to ten and several 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 shifts the process to step S19 and determines that the predetermined time T has not elapsed (step S18: Yes). 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 velocity ωsf.

Next, the control unit 36 switches the switch (step S20). The control unit 36 connects the common contact 310 and the contact 2 of the third switch 31. As a result, 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 unit 36 starts the 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 above equation (4), while causing the δ-axis voltage output processor 20 to output the above (9). ) Δ-axis voltage Vsδ * (if αv1 is given by the above equation (7), δ-axis voltage Vsδ * = Vδof + (1 + k / I0) ・ αv ・ T, αv1 is the above equation (8). If it is given in, a constant voltage of δ-axis voltage Vsδ * = Vδof + k · αv · T) is continuously output (step S23).

Next, the control unit 36 performs the phase adjustment process (step S22). From step S21, the control unit 36 causes the γ-axis voltage output processor 19 to update and output the γ-axis voltage Vsγ * according to the above equation (4), and finally updates the δ-axis voltage output processor 20 in step S19. While continuously outputting the voltage Vsδ *, the velocity estimator 30 is made to estimate the angular velocity ωse'and output it (step S24).

Next, the control unit 36 determines whether or not a predetermined estimated time sufficient to complete the phase adjustment process has elapsed since the execution of step S20 (step S23). The predetermined time varies depending on the apparatus to which the present invention is applied, but is about several seconds. When the control unit 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 control unit 36 shifts the process to step S24 and has a sufficiently predetermined time. If it is determined that the estimated time has not elapsed (step S23: No), the process returns to step S22.

In step S24, the control unit 36 performs an initialization process as a pre-stage of shifting from the phase adjustment process to the normal operation. The control unit 36 initializes (1) the initial value of the integrator of the axis error detection and the speed estimator 34 with the angular velocity ωse'estimated immediately before by the speed estimator 30, and (2) adjusts the speed controller 12. Initialize with the current command value Iδ generated immediately before, (3) initialize the d-axis current controller 16 with Vsγ * -ωe · Lq · Iδ, and (4) initialize the q-axis current controller 17 with Vsδ * + ωe ·. Initialize with (Ld · Iγ + φ).

Next, the control unit 36 switches the switch (step S25). The control unit 36 connects the common contact 210 of the first switch 21 and the contact 1, connects the common contact 220 of the second switch 22 and the contact 1, 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).

The above-mentioned steps S12 to S15 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 the general acceleration operation start-up method, the risk of step-out in mode transition is unavoidable unless the load state is strictly estimated and the voltage characteristics and command angular velocity characteristics are reset. This is because the estimation of the load state includes a considerable amount of error, and the adjustment of the applied voltage and the angular velocity in the mode transition requires considerable rigor. However, in the embodiment, the load is detected before the mode shift, the acceleration operation is performed with the voltage characteristics corresponding to the load, and then the phase adjustment process is performed. 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 process. That is, strictness is not required for load detection before mode transition, and it is possible to set an extremely wide range of load fluctuations that can be started. In the embodiment in which the load state is monitored and the start characteristics are changed, a wider range of suitable motor control can be performed by performing the phase adjustment process before the mode transition.

The above-described embodiment and the specific names, processes, controls, and information including various data and parameters shown are merely examples, and can be appropriately changed unless otherwise specified. Further, the configurations of each part or each device in the above-described embodiment may be appropriately dispersed or integrated in consideration of the processing load, mounting efficiency, and the like.

The broader aspects of the above embodiments are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the general concept or scope of the invention as defined by the appended claims and their equivalents.

M motor 10 motor controller 11 subtractor 12 speed controller 14 subtractor 15 subtractor 16 d-axis current controller 17 q-axis current controller 18 decoupling processor 19 γ-axis voltage output processor 20 δ-axis voltage output processing Instrument 21 1st switch 210 Common contact 22 2nd 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 device 30-2 Coefficient device 30-3 Integrator 30-4 Adder 31 Third switch 310 Common Contact 32 Integrator 33 Load detector 34 Axis error detector and speed estimator 35 Divider 36 Control unit

Claims (5)

A motor control device having a drive unit for driving a motor and a current detection unit for detecting the current of the motor.
A load detection unit that detects the load of the motor and
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 the motor is driven from the first time to the first time. The acceleration operation section up to time 2 is provided with a drive control unit that controls the drive unit so as to drive the motor based on the δ-axis voltage and the command angular velocity that increase with the passage of time.
The load detection unit detects the load of the motor in the load detection section and determines the load of the motor.
The drive control unit drives the motor so as to change the characteristics of the δ-axis voltage that increases with the passage of time in the acceleration operation section according to the load detected by the load detection unit. A motor control device characterized by controlling a unit. 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, which increases with the passage of time, at a high rate of increase. When the load detected by the load detection unit is equal to or less than a predetermined reference load, the characteristics of the delta-axis voltage, which increases with the passage of time, are not changed. The motor control device according to claim 1. The motor control device according to claim 1 or 2, wherein the load detection unit detects the load of the motor based on the current of the motor detected by the current detection unit. The load detection unit detects the load of the motor based on the difference or ratio between the current of the motor detected by the current detection unit and a reference current determined in advance corresponding to the reference load. The motor control device according to claim 3. Further provided is an estimation unit that estimates the angular velocity that makes the γ-axis current 0 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.
In the phase adjustment section from the second time to the third time, the drive control unit performs the current detection unit based on the rotation angle obtained by integrating and controlling the angular velocity estimated by the estimation unit. The γ-axis voltage and the δ-axis voltage corresponding to the γ-axis current and the δ-axis current of the motor in the γ-δ coordinate system detected by the above are the voltages in the fixed coordinate system when the motor is driven by the drive unit. The motor control device according to any one of claims 1 to 4, wherein the motor control device is characterized by converting to.

Images