JP6834331B2 - Permanent magnet synchronous motor control device, control method, and image forming device - Google Patents

Description

The present invention relates to a control device, a control method, and an image forming device for a permanent magnet synchronous motor.

In general, a permanent magnet synchronous motor (PMSM) has a stator having a winding wire and a rotor using a permanent magnet, and rotates by passing an AC current through the winding wire to generate a rotating magnetic field. Rotate the child in sync with it. According to the vector control that controls the alternating current as a component of the vector of the dq coordinate system, the rotation can be performed efficiently and smoothly.

In recent years, sensorless permanent magnet synchronous motors have been widely used. The sensorless type does not have a magnetic sensor or encoder for detecting the magnetic pole position. Therefore, for vector control of the sensorless type permanent magnet synchronous motor, a method of estimating the magnetic pole position and rotation speed of the rotor based on the current or voltage of the winding is used. However, when the rotation speed is small, such as at the start and stop of rotation, the magnetic pole position and rotation speed cannot be estimated with a predetermined accuracy. In that case, the magnetic pole position and rotation speed are estimated. Control is performed to generate a predetermined magnetic field without doing so.

Controls to stop the rotor include short-brake control that short-circuits the current path of the drive circuit so as to stop the current supply and extract energy from the permanent magnet synchronous motor, and free-run control that simply stops the current supply. There is.

However, when the rotor is stopped by these controls, the stop position of the rotor is not constant due to the influence of variations in load or inertial force. Therefore, when the rotation is restarted after the stop, the magnetic pole position in the stopped state must be estimated by some method, and the start of the rotation is delayed by the time required for the estimation. Further, the sensorless permanent magnet synchronous motor cannot be used for applications in which the load needs to be positioned at a predetermined stop position when stopped.

As a prior art for stopping the rotor of a sensorless permanent magnet synchronous motor at a desired position, there is a technique described in Patent Document 1 relating to control of a linear synchronous motor. In Patent Document 1, a continuously changing d-axis electric angle corresponding to a position command continuously given from a host control device is generated, and a current flows through the d-axis armature and a current flows through the q-axis armature. It is disclosed to control the current flowing through the armature so that it does not flow.

Japanese Patent No. 5487105

The technique of Patent Document 1 described above is for driving a linear synchronous motor composed of a mover traveling straight and a stator over the entire length of the moving range, and the position of the moving mover is changed every moment. It is assumed that the position command to specify is given.

Therefore, in this case, it is necessary to continuously generate a position command for designating the position of the mover, which complicates control.

When stopping the rotor of the permanent magnet synchronous motor, it is preferable that the stop position can be finely set in small steps. That is, it is preferable that the options for setting the stop position are, for example, 360 fine positions in 1 degree increments rather than 6 rough positions in 60 degree increments at the machine angle. It is even better if it is stepless.

Further, especially when positioning the load at the time of stopping, positioning with high accuracy so that the magnetic pole does not stop before reaching the desired position and does not stop past the desired position. Is required to do. Further, in particular, when some processing is started when the stop is completed, it is required to shorten the time required for the stop to be completed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device and a control method capable of stopping the rotor of a permanent magnet synchronous motor at a desired position.

The control device according to the embodiment of the present invention is a control device for a permanent magnet synchronous electric motor in which a rotor using a permanent magnet is rotated by a rotating magnetic field generated by an electric current flowing through the armature, and the electric current is passed through the armature. The drive unit that drives the rotor, the estimation unit that estimates the magnetic pole position of the rotor based on the current flowing through the armature, and the drive unit that estimates the rotational magnetic field based on the estimated magnetic pole position. It has a control unit that controls the unit and controls the drive unit so that the rotor is stopped when a stop command is input, and the control unit controls the rotation as a control for stopping the rotor. The current that generates the magnetic field vector that draws the child magnetic pole position to the stop position and stops it, the estimated latest magnetic pole position, the advance amount that is the rotation angle from the latest magnetic pole position to the stop position, and the permanent magnet. It is determined based on the load condition of the synchronous electric motor, and the drive unit is controlled so that the determined current continues to flow through the armature , and it corresponds to the basic current set value corresponding to the advance angle amount and the load condition. The current set value is determined using the correction amount determined in the above, the current is determined so that the magnitude of the magnetic field vector corresponds to the current set value, and the inertia and the advance angle are used as the correction amount. Use the set value according to the combination with the amount.

According to the present invention, it is possible to provide a control device and a control method capable of stopping the rotor of a permanent magnet synchronous motor at a desired position.

It is a figure which shows the outline of the structure of the image forming apparatus provided with the motor control apparatus which concerns on one Embodiment of this invention. It is a figure which shows typically the structure of the brushless motor. It is a figure which shows the dq axis model of a brushless motor. It is a figure which shows an example of the functional structure of a motor control device. It is a figure which shows the example of the structure of the motor drive part and the current detection part. It is a figure which shows the example of the drive sequence at the time of stop. It is a figure which shows the example of setting of the magnetic field vector for stopping a rotor. It is a figure which shows the example of the current vector corresponding to the magnetic field vector. It is a figure which shows the force acting on a rotor in a fixed excitation control. It is a figure which shows the example of the transition of the magnetic pole position in the process of stopping a rotor. It is a figure which shows the pull-in feed amount which concerns an experiment for determining a current basic set value and a current correction amount. It is a figure which shows a part of the result of the experiment for determining the current basic setting value and the current correction amount. It is a figure which shows the example of the structure of the storage part and the measurement part in a motor control device. It is a figure which shows the 1st example of the table group used for determining a current in a fixed excitation control. It is a figure which shows the 2nd example of the table group used for determining the electric current in fixed excitation control. It is a figure which shows the 3rd example of the table group used for determining a current in fixed excitation control. It is a figure which shows the 4th example of the table group used for determining a current in fixed excitation control. It is a figure which shows the flow of processing in a motor control device. It is a figure which shows the example of the process flow of the fixed excitation control. It is a figure which shows the example of the flow of the process which determines the current basic set value in fixed excitation control.

FIG. 1 schematically shows an outline of the configuration of an image forming apparatus 1 including a motor control device 21 according to an embodiment of the present invention, and FIG. 2 schematically shows a configuration of a brushless motor 3.

In FIG. 1, the image forming apparatus 1 is a color printer provided with an electrophotographic printer engine 1A. The printer engine 1A has four imaging stations 11, 12, 13, and 14 in parallel with four color toner images of yellow (Y), magenta (M), cyan (C), and black (K). To form. Each of the imaging stations 11, 12, 13 and 14 has a tubular photoconductor, a charged charger, a developing device, a cleaner, a light source for exposure, and the like.

The four-color toner images are first transferred to the intermediate transfer belt 16 and secondarily transferred to the paper 9 which is drawn out from the paper cassette 10 by the paper feed roller 15A and conveyed via the resist roller pair 15B. After the secondary transfer, the paper 9 is fed through the inside of the fuser 17 to the upper output tray 18. When passing through the fuser 17, the toner image is fixed on the paper 9 by heating and pressurizing.

The image forming apparatus 1 includes a plurality of brushless motors 3 as a drive source for rotating a rotating body such as a fixing device 17, an intermediate transfer belt 16, a paper feed roller 15A, a resist roller 15B, a photoconductor, and a roller of a developing device. Use a brushless motor. That is, the printer engine 1A conveys the paper 9 using the rotating bodies rotationally driven by these brushless motors to form an image on the paper 9.

The brushless motor 3 is arranged, for example, in the vicinity of the imaging station 14, and rotationally drives the resist roller pair 15B. The brushless motor 3 is controlled by the motor control device 21.

In FIG. 2, the brushless motor 3 is a sensorless type permanent magnet synchronous motor (PMSM). The brushless motor 3 includes a stator 31 as an armature that generates a rotating magnetic field, and a rotor 32 that uses a permanent magnet. The stator 31 has U-phase, V-phase, and W-phase cores 36, 37, 38 arranged at 120-degree intervals, and three Y-connected windings (coils) 33, 34, 35. A rotating magnetic field is generated by passing a three-phase alternating current of U-phase, V-phase, and W-phase through windings 33 to 35 to excite cores 36, 37, and 38 in order. The rotor 32 rotates in synchronization with this rotating magnetic field.

In the example shown in FIG. 2, the number of magnetic poles of the rotor 32 is 2. However, the number of magnetic poles of the rotor 32 is not limited to 2, and may be 4, 6 or more. The rotor 32 may be an outer type or an inner type. Further, the number of slots of the stator 31 is not limited to three. In any case, the motor control device 21 performs vector control (sensorless vector control) for the brushless motor 3 to estimate the magnetic pole position and the rotation speed using a control model based on the dq coordinate system. Will be.

In the following, the rotation angle position of the N pole indicated by the black circle among the S pole and the N pole of the rotor 32 may be referred to as the “magnetic pole position PS” of the rotor 32.

FIG. 3 shows a dq-axis model of the brushless motor 3. In the vector control of the brushless motor 3, the three-phase alternating current flowing through the windings 33 to 35 of the brushless motor 3 is converted into a direct current flowing through the two-phase windings rotating in synchronization with the permanent magnet which is the rotor 32. To simplify control.

The magnetic flux direction (direction of the north pole) of the permanent magnet is defined as the d-axis, and the direction advanced by π / 2 [rad] (90 °) in electrical angle from the d-axis is defined as the q-axis. The d-axis and the q-axis are model axes. With reference to the U-phase winding 33, the lead angle of the d-axis with respect to this is defined as θ. This angle θ indicates the angular position (magnetic pole position PS) of the magnetic pole with respect to the winding 33 of the U phase. The dq coordinate system is located at a position advanced by an angle θ with respect to the U-phase winding 33.

Since the brushless motor 3 does not have a position sensor for detecting the angular position (magnetic pole position) of the rotor 32, the motor control device 21 estimates the magnetic pole position PS of the rotor 32, that is, the angle θ, and estimates the angle θ. The rotation of the rotor 32 is controlled by using the estimated angle θm which is the angle θ.

FIG. 4 shows an example of the functional configuration of the motor control device 21, and FIG. 5 shows an example of the configuration of the motor drive unit 26 and the current detection unit 27 in the motor control device 21, respectively.

As shown in FIG. 4, the motor control device 21 includes a motor drive unit 26, a current detection unit 27, a vector control unit 24, a speed / position estimation unit 25, a storage unit 28, a measurement unit 29, and the like. Of these elements, the storage unit 28 and the measurement unit 29 are involved in a process for stopping the brushless motor 3.

The motor drive unit 26 is an inverter circuit for driving the rotor 32 by passing an electric current through the windings 33 to 35 of the brushless motor 3. As shown in FIG. 5, the motor drive unit 26 has three dual elements 261,262,263, a predrive circuit 265, and the like.

Each of the dual elements 261 to 263 is a circuit component in which two transistors having the same characteristics (for example, a field effect transistor: FET) are connected in series and housed in a package.

The dual elements 261 to 263 control the current I flowing from the DC power supply line 211 to the ground line via the windings 33 to 35. Specifically, the transistors Q1 and Q2 of the dual element 261 control the current Iu flowing through the winding 33, and the transistors Q3 and Q4 of the dual element 262 control the current Iv flowing through the winding 34. Then, the current Iw flowing through the winding 35 is controlled by the transistors Q5 and Q6 of the dual element 263.

In FIG. 5, the predrive circuit 265 converts the control signals U +, U−, V +, V−, W +, W− input from the vector control unit 24 into voltage levels suitable for the transistors Q1 to Q6. The converted control signals U +, U−, V +, V−, W +, and W− are input to the control terminals (gates) of the transistors Q1 to Q6.

The current detection unit 27 has a U-phase current detection unit 271 and a V-phase current detection unit 272, and detects currents Iu and Iv flowing through the windings 33 and 34. Since Iu + Iv + Iw = 0, the current Iw can be obtained by calculation from the detected values of the currents Iu and Iv. It may have a W-phase current detection unit.

The U-phase current detection unit 271 and the V-phase current detection unit 272 amplify the voltage drop due to the shunt resistance with a small resistance value (1 / 10Ω order) inserted in the flow path of the currents Iu and Iv, and A / It is D-converted and output as a detected value of currents Iu and Iv. That is, the two-shunt method is detected.

The motor control device 21 can be configured by using a circuit component that integrates the motor drive unit 26 and the current detection unit 27.

Returning to FIG. 4, the vector control unit 24 controls the motor drive unit 26 according to the speed command value ω * indicated by the speed command S1 from the upper control unit 20. The host control unit 20 is a controller that is in charge of overall control of the image forming apparatus 1, and issues a speed command S1 when the image forming apparatus 1 is warmed up, a print job is executed, a power saving mode is entered, or the like. .. When commanding the stop of the rotation drive, the upper control unit 20 gives the speed command S1 to the vector control unit 24 with the speed command value ω * set to “0”. That is, the speed command S1 in this case becomes the stop command S1s.

The vector control unit 24 controls the motor drive unit 26 so that a rotating magnetic field based on the estimated magnetic pole position is generated, and also causes the motor drive unit 26 to stop the rotor 32 when the stop command S1s is input. Control.

As a control for stopping the rotor, the vector control unit 24 determines a current for generating a magnetic field vector that draws the magnetic pole position PS of the rotor 32 to the stop position and stops the rotor 32 based on the latest estimated magnetic pole position PS and the like. Then, the motor drive unit 26 is controlled so that the determined current continues to flow through the windings 33 to 35.

As shown in FIG. 4, the vector control unit 24 includes a speed control unit 41, a current control unit 42, and a PWM conversion unit 43. Each of these units performs the following processing when the speed command S1 from the upper control unit 20 is not the stop command S1s, that is, when the speed estimation value ωm is not “0”.

The speed control unit 41 sets the speed estimation value ωm closer to the speed command value ω * based on the speed command value ω * from the upper control unit 20 and the speed estimation value ωm from the speed / position estimation unit 25. The current command values Id * and Iq * of the q coordinate system are determined. The velocity estimate ωm is input periodically. The speed control unit 41 determines the current command values Id * and Iq * each time the speed estimation value ωm is input.

The current control unit 42 determines the voltage command values Vd * and Vq * in the dq coordinate system based on the current command values Id * and Iq *. The voltage command values Vd * and Vq * are given to the speed / position estimation unit 25, and the voltage command values Vd * and Vq * are set to the U phase, V phase, and the U phase, V phase, and based on the estimated angle θm from the speed / position estimation unit 25. Converts to W-phase voltage command values Vu *, Vv *, Vw *.

The PWM conversion unit 43 generates a pattern of control signals U +, U−, V +, V−, W +, W− based on the voltage command values Vu *, Vv *, Vw *, and outputs the pattern to the motor drive unit 26. The control signals U +, U-, V +, V-, W +, and W- are signals for controlling the frequency and amplitude of the three-phase AC power supplied to the brushless motor 3 by pulse width modulation (PWM). is there.

The velocity / position estimation unit 25 calculates the value of the W phase current Iw from each value of the U phase current Iu and the V phase current Iv detected by the current detection unit 27. Then, after performing three-phase to two-phase conversion of the values of the three-phase currents Iu, Iv, and Iw, the velocity estimated value ωm and the estimated angle are based on the voltage command values Vd *, Vq *, etc. from the current control unit 42. Find θm.

The velocity estimated value ωm is an example of an estimated value of the rotational speed of the rotor 32, and the estimated angle θm is an example of an estimated value of the magnetic pole position PS of the rotor 32. The speed estimation value ωm is input to the speed control unit 41, and the estimated angle θm is input to the speed control unit 41 and the current control unit 42.

The motor drive unit 26 is controlled by each unit of the vector control unit 24 and the speed / position estimation unit 25 to rotationally drive the brushless motor 3.

By the way, the motor control device 21 of the present embodiment has a function of stopping the rotor 32 of the brushless motor 3 at a desired stop position. Hereinafter, the configuration and operation of the motor control device 21 will be further described with a focus on this function.

The storage unit 28 shown in FIG. 4 stores the current basic set value Ib and the current correction amounts Ic and Ic2 related to the fixed excitation control for stopping the rotor 32 at a desired stop position. The measuring unit 29 measures the inertia Jr and the resistance load Tr related to the rotation of the rotor 32 based on, for example, the currents Iu and Iv detected by the current detecting unit 27 according to the measurement command S7 from the speed control unit 41. The configuration of the storage unit 28 and the measurement unit 29 will be described later.

FIG. 6 shows an example of the drive sequence at the time of stopping, FIG. 7 shows an example of setting the magnetic field vector 85 for stopping the rotor 32, and FIG. 8 shows an example of the current vector 95 corresponding to the magnetic field vector 85. , Each is shown. Further, FIG. 9 shows an example of the force acting on the rotor 32 in the fixed excitation control, and FIG. 10 shows an example of the transition of the magnetic pole position PS in the process of stopping the rotor 32.

In FIG. 6A, the stop command S1s is input from the host control unit 20 to the motor control device 21 at time t1. Before time t1, it is assumed that vector control is performed and the rotation speed (angular velocity) ω is kept constant. However, it may be accelerating or decelerating.

The motor control device 21 starts deceleration control when the stop command S1s is input. For example, the speed control unit 41 controls the rotation (frequency) of the rotating magnetic field by changing the current command values Id * and Iq * so that the rotation speed ω gradually decreases to a predetermined degree, and brakes the rotor 32. Call. Further, not limited to this, so-called three-phase short-circuit type short brake control or free run control may be performed as deceleration control. When performing short brake control, all the transistors Q1, Q3, and Q5 of the motor drive unit 26 are turned off, and all the transistors Q2, Q4, and Q6 are turned on. When performing free run control, all transistors Q1 to Q6 are turned off.

The deceleration control is continued until the rotation speed ω drops to a preset control switching speed ω2 equal to or higher than the lower limit speed ω1. The lower limit speed ω1 is the lowest rotation speed ω at which the magnetic pole position PS can be estimated by the speed / position estimation unit 25 based on the currents Iu and Iv.

When the rotation speed ω drops to the control switching speed ω2 (time t2), the motor control device 21 switches the control to be executed from the deceleration control to the fixed excitation control.

The fixed excitation control is a control in which a current continues to flow through the windings 33 to 35 so as to generate a magnetic field that draws the magnetic pole of the rotor 32 to a predetermined stop position in order to stop the rotor 32. By performing the fixed excitation control, the rotor 32 stops at time t3 in the example of FIG. 6 (A).

FIG. 6B shows an example of a current in fixed excitation control.

In FIG. 6B, the currents Iu, Iv, and Iw of the windings 33 to 35 in the fixed excitation control are based on the latest magnetic pole position PS estimated at time t2, the advance angle amount described later, and the load condition. A fixed value of direct current to be determined. The latest magnetic pole position PS is based on the latest estimated angle θm. The latest magnetic pole position PS or the latest estimated angle θm may be substantially the latest.

In the fixed excitation control, the current command values Id * and Iq * are determined according to the advance angle amount and the load condition, and the determined current command values Id * and Iq * and the estimated angle θm at that time are fixed as they are. As a result, each current Iu, Iv, Iw becomes a DC current having a fixed value. Therefore, the magnitude and positive / negative direction of each current Iu, Iv, Iw are usually discontinuous and different from the time of deceleration control immediately before that. The current vector 95 described later is set by the current command values Id * and Iq *.

In the vector control up to the time t1, each current Iu, Iv, Iw is an alternating current for generating a rotating magnetic field. In the deceleration control up to time t2, for example, a current for braking the rotor 32 (deceleration current) flows. The currents Iu, Iv, and Iw of each winding at this time are, for example, alternating currents as shown by broken lines in the figure.

Further, in the fixed excitation control, the current I flowing from the DC power supply line 211 into the motor drive unit 26 becomes a substantially constant DC current.

The current in the fixed excitation control starts its flow from the time t2 when the control is switched to, but it is necessary to continue the current until the time t3 when the rotor 32 stops as the end point. When it is difficult to detect the stop of the rotor 32, the time required for the fixed excitation control (t3-t2) may be predicted, and the time may be passed until the time including the margin time elapses. In this case, the time may be set in advance in a table or the like in consideration of the amount of advance angle or the like.

Further, the current in the fixed excitation control may be started from time t2 and then continued to flow as it is until some control is started next time. In this case, since the stop position can be known by fixing the position of the rotor 32 in that state, there is an advantage that the next control becomes easy.

By the way, the estimated angle θm by the velocity / position estimation unit 25 is used for the fixed excitation control. Therefore, the control switching speed ω2 described above is set so that the timing of switching from deceleration control to fixed excitation control is within a period during which the speed / position estimation unit 25 can estimate.

Hereinafter, the fixed excitation control will be described in detail.

In FIGS. 7 to 9, the stop position Px, which is the position (target position) where the rotor 32 is to be stopped, is indicated by a double circle.

In FIGS. 7 to 9, the d-axis indicating the magnetic flux direction of the permanent magnet is substantially the same as the axis (so-called γ-axis) determined by the estimated angle θm, so that the d-axis and the q-axis are the γ-axis and Treat as equal to the δ axis. Further, the d-axis and the q-axis are axes that ideally indicate the magnetic flux direction of the permanent magnet, but the γ-axis and the δ-axis are actually estimated or detected via the estimated angle θm, and these are gradually approaching. The γ-axis and the δ-axis may be used in the actual control because they overlap with each other. That is, in the present embodiment, the γ-axis-δ-axis can be used instead of the d-q-axis, and Iγ, Iδ, and θm can be used instead of the Id, Iq, and θ.

When the control is switched to the fixed excitation control at the time point t2, the speed control unit 41 determines the magnetic field vector 85 from the rotation center of the rotor 32 toward the stop position Px, as shown in FIGS. 7A and 7B. The magnetic field vector 85 is a magnetic field that draws the rotor 32 into the stop position Px.

The stop position Px that determines the direction of the magnetic field vector 85 may be a position that rotates in the advancing direction with respect to the magnetic pole position PS as shown in FIG. 7 (A), or the magnetic pole as shown in FIG. 7 (B). It may be a position on the side that rotates in the delay direction with respect to the position PS.

In the case of FIG. 7A, the “advance angle amount dθ”, which is the rotation angle from the magnetic pole position PS to the stop position Px, is a positive value, and the maximum electric angle is 180 degrees. In the case of FIG. 7B, the “advance angle amount dθ” is a negative value, and its absolute value is the maximum (180-β) degree in the electric angle. β is the angle of the amount of rotation due to inertia in the advancing direction before starting to rotate in the lagging direction by the magnetic field vector 85.

Since the number of poles of the brushless motor 3 shown here is 2 and the electric angle and the mechanical angle are equal, the stop position is in the range of − (180-β) to +180 degrees in the mechanical angle with respect to the magnetic pole position PS. Can be Px.

The stop position Px may be a relative position determined based on the magnetic pole position PS at that time, or may be a predetermined fixed position (absolute position). The speed control unit 41 stores information for specifying the stop position Px.

When the stop position Px is a relative position, the advance angle amount dθ is predetermined. The stop position Px is specified by, for example, the angle θx from the angular position of the U-phase core 36 to the stop position Px. The angle θx is an angle corresponding to the sum of the estimated angle θm and the advance amount dθ.

When the stop position Px is set to a fixed position, an angle θx that specifies the stop position Px is predetermined. The advance angle dθ in this case is the difference between the estimated angle θm and the angle θx, and changes according to the magnetic pole position PS.

Determining the magnetic field vector 85 corresponds to defining the current vector 95 in the same direction as the magnetic field vector 85, as shown in FIG. 8 (A). The current vector 95 represents the current to be passed through the windings 33 to 35 to generate a magnetic field that draws the rotor 32 into the stop position Px.

Determining the current vector 95 is to set the direction and magnitude of the current vector 95 in the actual processing for controlling the motor drive unit 26. As the direction of the current vector 95, an estimated angle θm indicating the latest magnetic pole position PS (angle position on the d-axis) is set. Then, the d-axis component Id and the q-axis component Iq of the current vector 95 are set as the magnitude of the current vector 95. When the d-axis component Id, the q-axis component Iq, and the estimated angle θm are determined, the patterns of the control signals U +, U−, V +, V−, W +, and W− by the vector control unit 24 are determined, and the patterns are determined via the motor drive unit 26. The magnitude and direction of each of the flowing currents Iu, Iv, and Iw are determined.

As shown in FIG. 8B, the “current set value Ia”, which is a parameter representing the magnitude of the current vector 95, is set to an appropriate value so that the larger the advance angle amount dθ, the larger the value. That is, the magnetic pole position PS of the rotor 32 is pulled into the stop position Px and stops without reaching the stop position Px or greatly passing the stop position Px.

The speed control unit 41 sets the current set value Ia, calculates the d-axis component Id and the q-axis component Iq, sets the d-axis component Id as the current command value Id *, and sets the q-axis component Iq as the current command value Id *. , Continue to give to the current control unit 42. At this time, the velocity / position estimation unit 25 continues to give the estimated angle θm estimated immediately before switching to the fixed excitation control to the current control unit 42 as the latest estimated angle θm.

That is, in the fixed excitation control, the current command values Id *, Id * and the estimated angle θm are kept constant without being updated. As a result, the currents Iu, Iv, and Iw that generate the magnetic field vector 85 continue to flow through the windings 33 to 35, and the magnetic field vector 85 is maintained.

By the way, as shown in FIG. 9, when the fixed excitation control is performed, an inertial load Tj, a resistance load Tr, and a pulling force (rotational drive torque) Te act on the rotor 32.

The inertial load Tj is a force that causes the rotor 32 to continue rotating. The inertial load Tj depends on the total inertia (Jr) of the rotating portion, including the rotor 32, the resist roller pair 15B, and the means for transmitting the rotational force such as gears, and the angular acceleration (dω / dt). That is, when the advance amount dθ is a positive value, it is expressed as Tj = −Jr · (dω / dt), and when the advance angle amount dθ is a negative value, Tj = Jr · (dω). It is expressed as / dt).

The resistance load Tr is a sliding resistance that depends on the friction of the paper 9 or the machine, and acts to suppress rotation.

The pull-in force Te is a force generated by the magnetic field vector 85 and is proportional to the magnitude of the current vector 95. Specifically, it is expressed by the following equation, where the current set value is Ia, the interlinkage magnetic flux is φ, the q-axis component of the current vector 95 is Id, and the advance angle amount is dθ.

Te = φ ・ Id = φ ・ Ia ・ cos (π / 2-dθ) = φ ・ Ia ・ sin (dθ)
The fact that the inertial load Tj and the resistance load Tr act means that the load condition of the brushless motor 3 is related to the success or failure of the attraction of the magnetic pole position PS by the magnetic field vector 85 together with the advance angle amount dθ.

Therefore, the vector control unit 24 determines the current set value Ia based on the advance angle amount dθ and the load condition of the brushless motor 3. As described above, since the direction of the current vector 95 is set according to the magnetic pole position PS of the rotor 32, the vector control unit 24 sets the estimated latest magnetic pole position PS, the advance angle dθ, and the load condition. The current that produces the magnetic field vector 85 will be determined based on.

By determining the current in this way, the magnitude of the current can be set to the minimum required or close to the required magnitude, and the magnetic pole position PS is estimated as shown by the solid lines L1 and L4 in FIGS. 10A and 10B. It is possible to stop at or near the time t3 when the current is pulled from the position of the angle θm to the stop position of the angle θx.

If the current set value Ia is too large, as shown by the alternate long and short dash line L2 in FIG. 10 (A), the magnetic pole position PS passes the stop position and then vibrates so as to approach the stop position at the time point t4. It may stop. That is, an extra time is spent from the time point t3 to the time point t4 at which the vibration converges to stop. Therefore, for example, when the resist roller pair 15B is temporarily stopped and then the rotation is restarted, the restartable time may be delayed, the time required for image formation may be prolonged, and the productivity may be lowered.

Further, if the current set value Ia is too small, as shown by the alternate long and short dash line L3 in FIG. 10A, the magnetic pole position PS stops without reaching the stop position, and the magnetic pole position PS arrives at a desired stop position. May not be able to stop.

As described above, when the current set value Ia is not appropriate, the magnetic pole position PS of the rotor 32 does not stop at the desired stop position. Therefore, in the present embodiment, the current basic set value Ib and the current correction amounts Ic and Ic2 stored in the storage unit 28 are used to determine that the current set value Ia is appropriate. The basic current set value Ib and the current correction amounts Ic and Ic2 are determined in advance based on the results of an experiment or theoretical calculation.

FIG. 11 shows an example of the pull-in feed amount D2 related to the experiment for determining the current basic set value Ib and the current correction amounts Ic and Ic2, and FIG. 12 shows a part of the result of the experiment.

In FIG. 11, the paper 9 is conveyed toward the resist roller pair 15B in a state where the resist roller pair 15B is rotating at a constant speed corresponding to the transfer speed of the paper 9. When the tip of the paper 9 arrives at the position P1 on the upstream side of the resist roller pair 15B, for example, the upper control unit 20 that detects it gives a stop command S1s to the motor control device 21, and the deceleration control of the brushless motor 3 starts immediately. Will be done. Here, it is assumed that the acceleration (deceleration rate) in the deceleration control is constant.

When the tip of the paper 9 arrives at the position P2 downstream of the position P1, the deceleration control is switched to the fixed excitation control. Due to the fixed excitation control, the tip of the paper 9 arrives at the position P3 downstream of the position P2 and stops.

The distance D1 from the position P1 to the position P2 depends on the angular velocity of the rotor 32 at the start of the deceleration control, the reduction ratio of the gear that transmits the rotational driving force to the resist roller pair 15B, the deceleration rate in the deceleration control, and the control switching speed ω2. It is decided. That is, the position P2 is determined according to the deceleration control conditions in the drive sequence (operation pattern).

The distance from the position P2 to the position P3 (this is referred to as a “pull-in feed amount D2”) depends on the advance amount dθ when the current set value Ia is appropriate. Therefore, when the position P3 is to be an absolute position, that is, when the pull-in feed amount D2 is to be a fixed amount, the advance angle amount dθ is set so as to correspond to the pull-in feed amount D2, and the current set value Ia is set. Must be set to just the right value.

In FIG. 12A, the maximum value, the average value, and the average value when the current set value Ia is set to “0.3”, the setting of the advance angle amount dθ is changed, and the pull-in feed amount D2 is measured a plurality of times. The minimum value is shown. In FIG. 12B, the current set value Ia is set to “1.0”, and the maximum value, the average value, and the minimum value when the pull-in feed amount D2 is measured as in the case of FIG. 12A are It is shown. In any case, the paper 9 is plain paper (basis weight is about 60 g / square meter) generally used as copy paper.

In FIG. 12A, when the advance angle amount dθ is set to “1.5 [rad]” or less, the pull-in feed amount D2 increases according to the advance angle amount dθ. However, the pull-in feed amount D2 when the advance angle amount dθ is set to “1.5” is about 0.16 mm at the maximum, and the difference (variation) between the minimum value and the maximum value is large. When the advance amount dθ is set to a value larger than “1.5”, the pull-in feed amount D2 becomes smaller than when the advance amount dθ is set to “1.5”.

According to FIG. 12A, it can be seen that "when the current set value Ia is set to" 0.3 ", the pull-in feed amount D2 cannot be made larger than 0.16 mm".

In FIG. 12B, when the advance angle amount dθ is set to “2.5” or less, the pull-in feed amount D2 increases according to the advance angle amount dθ. In particular, when the advance angle amount dθ is within the range of “0” to “1.5”, the variation of the pull-in feed amount D2 is small.

According to FIG. 12B, “when the advance angle dθ is set to a value within the range of“ 0 ”to“ 1.5 ”, the current set value Ia is set to“ 1.0 ”. , The pull-in feed amount D2 becomes a value substantially proportional to the advance angle amount dθ. "

FIG. 13 shows an example of the configuration of the storage unit 28 and the measurement unit 29 in the motor control device 21.

The storage unit 28 includes a basic set value storage unit 28A, a load-specific set value storage unit 28B, a combination-specific set value storage unit 28C, and a paper type set value storage unit 28D.

The basic set value storage unit 28A stores the current basic set values Ib corresponding to each of the plurality of options of the advance angle amount dθ in the tables 81a, 81b, 81c, and 81d.

The current basic set value Ib is a basic value in setting the current set value Ia. That is, the value obtained by correcting the current basic set value Ib using the current correction amounts Ic and Ic2 according to the load condition is set as the current set value Ia. The current basic set value Ib has a margin for the minimum value of the current that can be stopped at the position set by the advance angle amount dθ when the load condition is a reference condition (for example, a non-conveyed state in which the paper 9 is not conveyed). It is defined to correspond to the current value to which the value is added.

The load-specific set value storage unit 28B collectively stores the load-specific set values corresponding to each of the plurality of values of the resistance load Tr in the tables 82a and 82b as the current correction amount Ic.

The combination-specific set value storage unit 28C stores in the tables 83a and 83b the combination-specific set values corresponding to each of the plurality of combinations of the inertia Jr and the advance angle amount dθ as the current correction amount Ic.

The paper type setting value storage unit 28D collectively stores the paper type setting values corresponding to each of the plurality of types of the paper 9 as the current correction amount Ic2 in the table 84.

The measuring unit 29 has a load measuring unit 29A and an inertia measuring unit 28B.

When the motor drive unit 26 is controlled by the vector control unit 24 so that the rotor 32 rotates at a constant speed, the load measurement unit 29A receives a measurement command S7 from the speed control unit 41.

The load measuring unit 29A measures the resistance load Tr based on the current I flowing through the stator 31 which is an armature when the measurement command S7 is input. At that time, as the current I, for example, the currents Iu and Iv detected by the current detection unit 27 are used. As a measurement process, the load measuring unit 29A obtains the current I from the currents Iu and Iv, reads the resistance load Tr corresponding to the obtained current I from the table showing the resistance load Tr corresponding to the current I, and controls the speed. Send to section 41. In the speed control unit 41, the resistance load Tr is stored as information for fixed excitation control.

When the motor drive unit 26 is controlled by the vector control unit 24 so that the rotation of the rotor 32 is accelerated, the inertia measurement unit 28B receives the measurement command S7 from the speed control unit 41. At this time, the measurement command S7 includes the angular acceleration α (α = dω / dt) of the rotor 32.

The inertia measuring unit 28B measures the inertia Jr based on the current I flowing through the stator 31 which is an armature when the measurement command S7 is input. As a measurement process, the inertia measuring unit 28B obtains the current I from the currents Iu and Iv, calculates the inertia Jr based on the following equation, and sends it to the speed control unit 41.

Jr = Kt ・ I / α
However, Kt is a torque constant according to the specifications of the brushless motor 3.

In the speed control unit 41, the inertia Jr is stored as information for fixed excitation control.

FIG. 14 shows a first example of the table group 80a used for determining the current in the fixed excitation control, and FIG. 15 shows a second example of the table group 80b. FIG. 16 shows a third example of the table group 80c, and FIG. 17 shows a fourth example of the table group 80d.

In FIG. 14, the table group 80a is composed of three tables 81a, 81b, 82a. This table group 80a can be suitably used when the inertia Jr hardly changes and the resistance load Tr may change.

In the tables 81a and 81b, each of the plurality of ranges of the advance angle amount dθ is associated with the current basic set value Ib. In table 81a, the current basic set value Ib (first current basic set value) when the advance angle amount dθ is a positive value is shown, and in Table 81b, when the advance angle amount dθ is a negative value. The current basic set value Ib (second current basic set value) is shown.

For example, in the table 81a, the range of the advance angle amount dθ is set to "0 or more and less than 1.5", "1.5 or more and less than 2.5", and "2.5 or more and less than π". The current basic set values Ib corresponding to each range are set to "0.8", "1.0", and "1.5".

In the table 82a, each of the plurality of values of the resistance load Tr is associated with the current correction amount Ic. The current correction amount Ic is a value to be added to the current basic set value Ib. Similarly, in the tables 82b, 82c, 83a, 83b, 83c described later, the values should be added.

Based on the table group 80a, the speed control unit 41 calculates the current set value Ia. That is, the current basic set value Ib corresponding to the preset advance angle amount dθ is read from the table 81a or the table 81b, and the current correction amount Ic corresponding to the resistance load Tr measured before switching to the fixed excitation control is set to the table 82a. Read from. Then, the current set value Ia is obtained by adding the read current basic set value Ib and the current correction amount Ic. The current set value Ia is expressed by the following equation.

Ia = Ib + Ic
For example, when the set value of the advance angle amount dθ is “1” and the measured resistance load Tr is “0.1”, the current basic set value Ib is “0.8” according to the table 81a. Yes, the current correction amount Ic is "0.2" according to the table 82a. Therefore, the current set value Ia is calculated as "1.0" by adding these.

In FIG. 15, the table group 80b consists of four tables 81a, 81b, 82b, 84. Of these, the tables 81a and 81b are the same as those of the table group 80a. The table group 80b can be preferably used when the user can input the type of the paper 9 to the image forming apparatus 1 or the image forming apparatus 1 can determine the type of the paper 9.

In the table 82b, each of the plurality of values of the resistance load Tr is associated with the current correction amount Ic. The plurality of values of the resistive load Tr are the same as those in Table 82a of FIG. 14, but the values of the corresponding current correction amounts Ic are different from the values in Table 82a.

Table 84 associates each of the plurality of types of paper 9 with the current correction amount Ic2. The types of paper 9 are "thin paper", "plain paper", "thick paper 1", "thick paper 2" and the like. The current correction amount Ic2 is a value to be added to the current basic set value Ib.

When the table group 80a is used, the load measuring unit 29A controls the motor 26 drive unit so that the rotor 32 rotates at a constant speed in a non-conveyed state in which the paper is not transported by the resist roller pair 15B. At this time, the resistance load Tr is measured based on the current I flowing through the windings 33 to 35.

Further, in this case, the upper control unit 20 notifies the motor control device 21 of the type of the paper 9. That is, the upper control unit 20 inputs the data signal S5 indicating the type of the paper 9 to the speed control unit 41 before issuing the stop command S1s (see FIG. 4).

The speed control unit 41 reads out the current basic set value Ib corresponding to the advance angle amount dθ from the table 81a or the table 81b, and reads out the current correction amount Ic corresponding to the resistance load Tr measured in the non-conveyed state from the table 82b. Further, the current correction amount Ic2 corresponding to the notified type of paper 9 is read from the table 84.

Then, the read current basic set value Ib and the current correction amount Ic are added to the current correction amount Ic2 to obtain the current set value Ia. That is, the current to be passed through the windings 33 to 35 is determined by correcting the current basic set value Ib by using the sum of the current correction amount Ic and the current correction amount Ic2. The current set value Ia is expressed by the following equation.

Ia = Ib + Ic + Ic2
For example, it is assumed that the set value of the advance angle amount dθ is “1”, the measured resistance load Tr is “0.1”, and the paper 9 is “plain paper”. In this case, according to the tables 81a, 82b, 84, the current basic set value Ib is "0.8", the current correction amount Ic is "0", and the current correction amount Ic2 is "2.0". is there. Therefore, the current set value Ia is calculated as "1.0".

In FIG. 16, the table group 80c consists of two tables 81c and 83a. This table group 80a can be suitably used when the resistance load Tr hardly changes and the inertia Jr may change significantly. For example, when the material of the roller or gear is changed due to parts replacement or design change, the inertia Jr may change significantly.

In the table 81c, each of the plurality of ranges of the advance angle amount dθ is associated with the current basic set value Ib. The range division of the advance angle amount dθ is the same as that in the table 81a of FIG. 14, but the value of the current basic set value Ib corresponding to each range is different from the value in the table 81a. In the table 81c, for example, the current basic set value Ib is determined in consideration of the correction amount corresponding to "plain paper".

Table 83a associates each of the plurality of combinations of the inertia Jr and the advance angle amount dθ with the current correction amount Ib as the set value for each combination.

In table 83a, the inertia Jr is divided into two ranges by a predetermined threshold Jr1. The advance angle dθ is divided into two for each of the range below the threshold value Jr1 and the range above the threshold value Jr1, and there are four combinations of the inertia Jr and the advance angle amount dθ.

When the inertia Jr is less than the threshold value Jr1, the inertial load Tj is small, so that the rotor 32 tends to stop. When the advance angle amount dθ is relatively small, it is considered that a sufficient pull-in force Te can be obtained with the current basic set value Ib, so the current correction amount Ib is set to “0”. When the advance angle dθ is relatively large, the current correction amount Ib is set to “0.20” so as to increase the pull-in force Te.

On the contrary, when the inertia Jr is equal to or higher than the threshold value Jr1, the inertial load Tj is large, so that the rotor 32 is unlikely to stop. When the advance angle dθ is relatively small, the current correction amount Ib is set to "0.20" so as to increase the pull-in force Te in order to keep the magnetic pole passing through the stop position Px at the stop position Px. .. When the advance angle dθ is relatively large, it is considered that the magnetic pole reaches the stop position Px without increasing the pull-in force Te, so the current correction amount Ib is set to “0”.

The speed control unit 41 calculates the current set value Ia by adding the current correction amount Ic corresponding to the measured inertia Jr to the current basic set value Ib corresponding to the set advance angle amount dθ.

In FIG. 17, the table group 80d consists of two tables 81d and 83b. This table group 80d can be preferably used when both the inertia Jr and the resistance load Tr may change.

Table 81d associates each of the plurality of ranges of the advance angle amount dθ with the current basic set value Ib. Table 83b associates each of the plurality of combinations of the inertia Jr, the advance angle amount dθ, and the load resistance Tr with the current correction amount Ib as a set value for each combination.

The speed control unit 41 sets the current set value Ia by adding the current correction amount Ic corresponding to the measured inertia Jr and the resistance load Tr to the current basic set value Ib corresponding to the set advance angle amount dθ. calculate.

FIG. 18 shows an example of the processing flow in the motor control device 21, FIG. 19 shows an example of the processing flow of the fixed excitation control, and FIG. 20 shows an example of the processing flow for determining the current basic set value Ib in the fixed excitation control. However, each is shown.

As shown in FIG. 18, it waits for the activation command to be given from the host control unit 20 (# 101). The start command is a speed command S1 issued when the rotor 32 is stopped, during deceleration control, or during fixed excitation control, and the speed command value ω * is a predetermined value corresponding to the transport speed of the paper 9. It was.

When a start command is given (YES at # 101), acceleration control is started (# 102), and inertia Jr is measured and stored during acceleration (# 103).

When the speed estimation value ωm reaches the speed command value ω * of the start command, the acceleration control is terminated, and instead, constant speed control for keeping the speed estimation value ωm constant is performed (# 104). During constant speed control, the resistance load Tr in the conveyed state in which the paper 9 is conveyed by the resist roller pair 15B or the resistance load Tr in the non-conveyed state in which the paper 9 is not conveyed is measured and stored (# 105).

After that, it waits for the stop command S1s to be given from the upper control unit 20 (# 106). When the stop command S1s is given (YES in # 106), the resistance control switching speed ω2 is set in the control register (# 107), and the deceleration control is started (# 108).

When the speed estimation value ωm drops to the control switching speed ω2 (YES in # 109), the control is switched from the deceleration control to the fixed excitation control, and the rotation of the brushless motor 3 is stopped by the fixed excitation control (# 110).

As shown in FIG. 19, in the fixed excitation control, the magnetic pole position PS is determined based on the latest estimated angle θm (# 301), and the advance angle dθ is determined (# 302). For example, in the mode in which the stop position Px is a position relative to the magnetic pole position PS, a preset advance angle amount dθ is set in the control register.

The current basic installation value Ib is determined according to the advance amount dθ (# 303), and the current correction amount Ic is determined (# 304). When the table group 80b is used as described above, the current correction amount Ic2 is also determined. Subsequently, the current set value Ia is calculated based on the current basic installation value Ib and the current correction amounts Ic and Ic2 (# 305).

The d-axis component Id and the q-axis component Iq of the current vector 95 are obtained using the calculated current set value Ia, and the current command values Id * and Iq * are determined (# 306).

Then, the motor drive unit 26 is controlled using the current command values Id *, Iq * and the estimated angle θm corresponding to the latest magnetic pole position PS (# 307). That is, the motor drive unit 26 is controlled so as to supply the current corresponding to the magnetic field vector 85 to the brushless motor 3.

As shown in FIG. 20, in the process of determining the current basic set value Ib, it is determined whether or not the advance angle amount dθ is a positive value (# 331). Here, as an example of the situation, it is assumed that the paper 9 is positioned at the position P3 shown in FIG. In the normal mode in which the paper 9 is conveyed at the first speed V1, the advance angle amount dθ is a positive value. However, in the high-speed mode in which the vehicle is conveyed at the second speed V2, which is faster than the speed V1, the distance D1 moved during the deceleration control becomes long, so that the position P2 at the end of the deceleration control may be downstream from the position P3. In this case, the advance angle amount dθ has a negative value.

When it is determined that the advance amount dθ is a positive value (YES in # 331), the current basic set value Ib corresponding to the advance amount dθ is obtained from the first table 81a shown in FIGS. 14 and 15. Read (# 332).

When it is determined that the advance angle amount dθ is a negative value (NO in # 331), the current basic set value Ib corresponding to the advance angle amount dθ is read out from the second table 81b (# 333).

According to the above embodiment, it is possible to provide a control device and a control method capable of stopping the rotor of the permanent magnet synchronous motor at a desired position. For example, the rotor can be stopped at a desired position even when the position command for specifying the rotation angle position is not given from the upper control unit 20 every moment.

In addition, since the current set value Ia is determined based on the advance angle amount dθ and the load condition of the brushless motor 3, the magnitude of the magnetic field vector 85 can be set to the minimum necessary or close to it. That is, it is possible to reduce the occurrence of excess or deficiency of rotation, such as stopping before reaching the desired position or stopping after passing the desired position. It is possible to reduce the vibration just before the stop and stop it more quickly and smoothly.

According to the embodiment described above, since the tables 81a to 81d, 82a, 82b, 83a, 83b, 84 are stored in the storage unit 28, the advance angle amount dθ, the inertia Jr, and the resistance load Tr are each single. Not limited to the value of. Therefore, the motor control device 21 can be used to control a brushless motor that rotationally drives various rotating bodies such as a transfer roller other than the resist roller 15B, a transfer roller, or a fixing roller. The motor control device 21 can be used for controlling the brushless motor in an image forming device other than the image forming device 1 or other devices.

According to the embodiment described above, fixed excitation control is performed by using a control method based on a control model based on a dq coordinate system, which is considered to pass a direct current through a two-phase winding with a three-phase alternating current. Therefore, the processing becomes simpler than the case where the value of each current of the three phases is calculated by another method. Since most of the components used for vector control for rotational drive can be diverted for fixed excitation control, the configuration of the motor control device 21 can be simplified as compared with the case where it is not diverted.

In the embodiment described above, the current correction amounts Ic and Ic2 are added to the current basic set value Ib. However, the present invention is not limited to this, and the current correction amounts Ic and Ic2 may be set as coefficients, and the product of the current basic set value Ib and the current correction amounts Ic and Ic2 may be calculated as the current set value Ia. Alternatively, the current basic set value Ib is set to be large, and the current correction amounts Ic and Ic are set so that the value obtained by subtracting the current correction amounts Ic and Ic2 from the current basic set value Ib becomes the desired current set value Ia. You may.

In the above-described embodiment, the current command values Id * and Iq * and the estimated angle θm are maintained to perform fixed excitation, but the present invention is not limited to this. The command value or control signal value determined or generated based on the current command values Id *, Iq * and the estimated angle θm may be stored. That is, if the two-phase voltage command values Vd *, Vq *, the three-phase voltage command values Vu *, Vv *, Vw *, or the winding currents Iu, Iv, Iw are stored, the windings 33 to 35 are constant. The rotor 32 can be stopped by controlling the motor drive unit 26 so that the current continues to flow.

In the above-described embodiment, the inertia Jr and the resistive load Tr are measured based on the detected currents Iu and Iv, but the correlation with the currents Iu and Iv such as the current command values Id * and Iq *. The inertia Jr and the resistive load Tr may be measured or estimated based on a certain value.

In the above-described embodiment, the time point at which the deceleration control is switched to the fixed excitation control is the time point at which a predetermined time has elapsed from the input of the stop command S1s or the time point at which the magnetic pole position PS cannot be estimated. be able to. In any case, the estimated angle θm is periodically acquired during the deceleration control. When free-run control is performed as deceleration control, short brake control is performed intermittently to detect currents Iu and Iv and acquire an estimated angle θm. When switching to fixed excitation control when the estimated angle θm cannot be acquired, the current command values Id * and Iq * are obtained using the last estimated angle θm acquired before switching to fixed excitation control.

In the embodiment described above, when the value of inertia Jr is fixed, the fixed value is stored in advance, and the process of measuring the inertia Jr (step # 103 in FIG. 18) is omitted. can do. The same applies to the resistance load Tr, and if it is confirmed, the determined value can be stored in advance, and the process of measuring the resistance load Tr (step # 105) can be omitted. ..

In the above-described embodiment, the configurations and data values of the tables 81 to 84 are examples, and various configurations or data values other than those shown in the drawings can be used. Further, the configuration of the storage unit 28 and the like can be variously changed.

In addition, the configuration, processing content, order, timing, etc. of the entire image forming device 1 and the motor control device 21 can be appropriately changed according to the gist of the present invention.

1 Image forming device 3 Brushless motor (permanent magnet synchronous motor)
9 Paper 15B Resist roller pair (conveyor roller)
21 Motor control device (control device)
24 Vector control unit (control unit)
25 Velocity / position estimation unit (estimation unit)
26 Motor drive unit (drive unit)
28 Storage unit 28A Basic set value storage unit (storage unit)
28B Load-specific set value storage unit (storage unit)
28C Combination set value storage unit (storage unit)
28D Paper type setting value storage unit (storage unit)
29 Measuring unit 31 Stator (armature)
32 Rotor 33, 34, 35 Winding 41 Speed control 42 Current control 85 Magnetic field vector 95 Current vector dθ Advance amount I Current Iu, Iv, Iw Current Ia Current set value Ib Current basic set value (1st current basic) Set value, second basic current set value)
Ic current correction amount (correction amount, set value)
Id d-axis component Iq q-axis component Jr inertia (load condition)
Tr resistance load (load condition)
PS magnetic pole position Px stop position S1s stop command θm estimated angle (estimated magnetic pole position)
ω Rotation speed (speed)

Claims (6)

A control device for a permanent magnet synchronous motor in which the rotor using a permanent magnet is rotated by a rotating magnetic field generated by an electric current flowing through the armature.
A drive unit that drives the rotor by passing an electric current through the armature,
An estimation unit that estimates the magnetic pole position of the rotor based on the current flowing through the armature,
A control unit that controls the drive unit so that the rotating magnetic field is generated based on the estimated magnetic pole position, and controls the drive unit so that the rotor stops when a stop command is input. Have and
As a control for stopping the rotor, the control unit draws the magnetic pole position of the rotor to the stop position and generates a current for generating a magnetic field vector to stop the rotor, from the estimated latest magnetic pole position and the latest magnetic pole position. wherein the rotation is the angle advance amount to the stop position determined based on the load condition of the permanent magnet synchronous motor, and the determined current and controls the drive unit to continue to flow in the armature, the The current set value is determined using the current basic set value corresponding to the advance angle amount and the correction amount determined according to the load condition so that the magnitude of the magnetic field vector becomes the magnitude corresponding to the current set value. The current is determined, and a set value corresponding to the combination of the inertia and the advance angle amount is used as the correction amount .
A control device for a permanent magnet synchronous motor. The current basic set value is defined to correspond to a current value obtained by adding a margin value to the minimum value of the current when the load condition is a reference condition.
The control device for a permanent magnet synchronous motor according to claim 1. A combination-specific setting value storage unit that stores a combination-specific setting value corresponding to each of a plurality of combinations of the inertia and the advance angle amount as the setting value.
It has an inertia measuring unit that measures the inertia based on the current flowing through the armature when the driving unit is controlled so that the rotation of the rotor is accelerated.
The control unit uses the set value for each combination corresponding to the measured inertia as the correction amount.
The control device for a permanent magnet synchronous motor according to claim 1. The control unit determines the current using the d-axis component and the q-axis component of the current vector in the dq coordinate system corresponding to the magnetic field vector at the stop position.
The control device for a permanent magnet synchronous motor according to any one of claims 1 to 3. An image forming device that forms an image on paper.
A permanent magnet synchronous motor in which the rotor using a permanent magnet rotates due to the rotating magnetic field generated by the current flowing through the armature.
A transport roller that is rotationally driven by the permanent magnet synchronous motor to transport the paper,
It has a control device for controlling the permanent magnet synchronous motor, and
The control device is
A drive unit that drives the rotor by passing an electric current through the armature,
An estimation unit that estimates the magnetic pole position of the rotor based on the current flowing through the armature,
A control unit that controls the drive unit so that the rotating magnetic field is generated based on the estimated magnetic pole position, and controls the drive unit so that the rotor stops when a stop command is input. Have and
As a control for stopping the rotor, the control unit draws the magnetic pole position of the rotor to the stop position and generates a current for generating a magnetic field vector to stop the rotor, from the estimated latest magnetic pole position and the latest magnetic pole position. wherein the rotation is the angle advance amount to the stop position determined based on the load condition of the permanent magnet synchronous motor, and the determined current and controls the drive unit to continue to flow in the armature, the The current set value is determined using the current basic set value corresponding to the advance angle amount and the correction amount determined according to the load condition so that the magnitude of the magnetic field vector becomes the magnitude corresponding to the current set value. The current is determined, and a set value corresponding to the combination of the inertia and the advance angle amount is used as the correction amount .
An image forming apparatus characterized in that. This is a control method for a permanent magnet synchronous motor in which the rotor uses a permanent magnet to rotate due to the rotating magnetic field generated by the current flowing through the armature.
As a control for stopping the rotor, the current that generates a magnetic field vector that draws the magnetic pole position of the rotor to the stop position and stops the rotor is the magnetic pole position at that time and the rotation angle from the magnetic pole position to the stop position. It is determined based on the amount of advance and the load condition of the permanent magnet synchronous electric motor, and fixed excitation control is performed to keep the determined current flowing through the armature, and the basic current set value corresponding to the amount of advance is used. The current set value is determined using the correction amount determined according to the load condition, the current is determined so that the magnitude of the magnetic field vector corresponds to the current set value, and the correction amount is set as the correction amount. Use the set value according to the combination of the inertia and the advance amount .
A method of controlling a permanent magnet synchronous motor, which is characterized in that.

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