WO2018021983A1 - A rotor alignment method - Google Patents

A rotor alignment method Download PDF

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Publication number
WO2018021983A1
WO2018021983A1 PCT/TR2016/050246 TR2016050246W WO2018021983A1 WO 2018021983 A1 WO2018021983 A1 WO 2018021983A1 TR 2016050246 W TR2016050246 W TR 2016050246W WO 2018021983 A1 WO2018021983 A1 WO 2018021983A1
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WO
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Prior art keywords
rotor
speed
reference current
idref
axial reference
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PCT/TR2016/050246
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French (fr)
Inventor
Sinan YILMAZ
Original Assignee
Aselsan Elektronik Sanayi Ve Ticaret Anonim Sirketi
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Publication of WO2018021983A1 publication Critical patent/WO2018021983A1/en

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/34—Arrangements for starting
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
    • H02P25/02—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the kind of motor
    • H02P25/022—Synchronous motors
    • H02P25/03—Synchronous motors with brushless excitation
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/14—Electronic commutators
    • H02P6/16—Circuit arrangements for detecting position
    • H02P6/17—Circuit arrangements for detecting position and for generating speed information

Definitions

  • the present invention relates to a rotor alignment method wherein Permanent Magnet Synchronous Motors (PMSM) are aligned with a phase axis of a stator.
  • PMSM Permanent Magnet Synchronous Motors
  • PMSM Permanent Magnet Synchronous Motor
  • FOC Field Oriented Control
  • the position of the rotor relative to the stator can be calculated by using the back-emf which occurs.
  • back-emf will not occur when the rotor is at the start (rotor at zero speed)
  • the initial position of the rotor relative to the stator is generally performed with absolute positions sensors (absolute encoder, resolver) to be placed on the PMSMs, or a relative position sensors (encoders) (Incremental angle encoder). Even if the initial value of the rotor angle is known with the absolute encoders, they cause size and weight limitations and increase in costs in PMSM systems.
  • the most common one of the methods carried out for bringing the rotor to a known position is to form a magnetic field on A phase axis as a result of the stator current vector (Is) being formed on the A phase vector of the stator, and the said magnetic field aligning with the A phase axis of the rotor as a result of interaction with the magnetic field of the rotor, which is called as alignment.
  • the rotor angle ( ⁇ ) is positioned such that it will be 0° with the A phase axis, and thus the position of the rotor relative to the stator is determined.
  • the method of applying Vi(100) vector shown in Figure 3 can be performed.
  • the method of applying the V 2 (110) vector first and then the Vi(100) vector, thus aligning the rotor with the A phase may be applied [G.L.Cascella, F.Cupertino,L.Salvatore,S.Stasi "PMSM Rotor Double- Alignment by PI and Sliding-Mode Controllers," IEEE, ppl741-1747, 2003].
  • the size and application time of the applied vector becomes important. If the vector is not large enough, the rotor does not move. If the vector is larger than it is required, the rotor makes an uncontrolled sudden movement.
  • the required torque value to be applied varies dynamically.
  • the sudden movement may damage the PMSM system or may cause an unwanted oscillation.
  • the rotor may be hung on an axis other than the phase axis.
  • the vector should be applied until the oscillation made by the rotor around the A phase ends in order to completely the alignment properly.
  • the time passing for the oscillation to end causes time loss in the alignment.
  • the said time loss causes PMSMs with the incremental angle encoder not to be used in critical application wherein the credibility should be in high levels.
  • the objective of the present invention is to provide a method for bringing the rotor to a a known position relative to the stator when the rotor is at zero speed at the start for Permanent Magnet Synchronous Motors (PMSM) using incremental angle encoder.
  • PMSM Permanent Magnet Synchronous Motors
  • Figure 1 is the schematic view of the vector structures used in Field Oriented Control (FOC) of the Permanent Magnet Synchronous Motor (PMSM) in an exemplary embodiment of the invention.
  • FOC Field Oriented Control
  • PMSM Permanent Magnet Synchronous Motor
  • Figure 2 shows the currents applied according to D-Q axis set in an exemplary embodiment of the invention.
  • FIG. 3 shows the current vectors that can apply on the Permanent Magnet Synchronous Motor (PMSM) in an exemplary embodiment of the invention.
  • PMSM Permanent Magnet Synchronous Motor
  • a rotor (2) alignment method which enables the rotor (2) to be aligned with the A phase axis at the start for Permanent Magnet Synchronous Motors (PMSM) (1) using incremental angle encoder, comprises the steps of
  • stator (3) applying a rotor axial reference current (Idref) to the stator (3) reels such that magnetic field will be generated in A phase axis of the stator (3);
  • an incremental angle encoder measuring the speed of the rotor (2) continuously or in selected time intervals
  • a speed controller decreasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below a selected rotor (2) speed;
  • PMSM Permanent Magnet Synchronous Motors
  • At least one speed controller applying a rotor axial reference current (Idref) to the stator (3) reels such that magnetic field will be generated in A phase axis of the stator (3);
  • Idref rotor axial reference current
  • an incremental angle encoder measuring the speed of the rotor (2) continuously or in selected time intervals
  • PMSM Permanent Magnet Synchronous Motor
  • the rotor (2) (the movable part, component) is brought to a position selected relative to the stator (3). More specifically, the rotor axis (d) is aligned with the A phase axis of the stator (3) in the rotor (2) alignment method.
  • the output of a speed controlled preferably in a Field Oriented Control (FOC) algorithm is considered as rotor axial reference current (Idref) instead of vertical axial reference current to the rotor (Iqref), being different from the classis method.
  • Vertical axial reference current to the rotor (Iqref) is considered as zero (0).
  • a rotor axial reference current (Idref) is given to the stator (3) reels by considering the rotor angle ( ⁇ ) (rotor position information in terms of angle) 0 such that magnetic field will be generated in A phase axis of the stator (3).
  • the magnetic field in the A phase axis generated with the rotor axial reference current (Idref) interacts with the magnetic field of the rotor (2), and applies a force and torque on the rotor (2) in direction of the A phase axis.
  • the rotor (2) moves towards the A phase axis as a result of the applied torque.
  • the torque value generated on the rotor (2) depends on the angle between the A phase axis and the rotor axis (d) (the axis of the rotor (2) magnetic field) and the rotor axial reference current (Idref). In a position wherein the A phase axis and the rotor axis (d) are vertical to each other, the torque value generated on the rotor (2) is at the highest level, in the position wherein they are parallel to the each other (the angle between the A phase axis and the rotor axis is 0° or 180°) the torque value generated on the rotor (2) is zero (0).
  • the torque value generated in a reference current with constant rotor axis (Idref) can decrease and increase according to the varying angle.
  • the rotor (2) speed changes during alignment process.
  • the said variance in the speed causes the alignment process to take longer time and/or the oscillation of the rotor (2) in A phase axis.
  • the alignment time is shortened by changing the rotor axial reference current (Idref) applied such that the rotor (2) speed will be fixed.
  • An incremental angle encoder measures the speed of the rotor (2) continuously or in selected time intervals.
  • a speed controller increases or decreases rotor axial reference current (Idref) so that the rotor (2) speed remains at a selected rotor speed value.
  • the speed controller decreases the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increases the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below a selected rotor (2) speed. Therefore, the rotor (2) moves towards the A phase axis of the stator (3) at a selected rotor (2) speed by rotating.
  • the selected rotor (2) speed is preferably selected at the highest level at which the rotor (2) will not make oscillation. Since the torque value that will move the rotor (2) changes depending on the environmental conditions directly such as temperature, expansion as a result of temperature change, friction; the required torque value to be applied varies dynamically.
  • the alignment control is performed independent from the torque value, depending on the rotor (2) speed; the alignment time is not affected by the said dynamic variants. As a result of the rotor (2) moving much faster than desired; with the rotor (2) alignment method, the time losses that can causes by the oscillation in A phase axis and the effects causes by the dynamic variants are eliminated, and thus the alignment process is carried out much faster relative to the previous technique.
  • the speed controller starts to continuously increase the rotor axial reference current (Idref), however the torque cannot be generated and the rotor (2) does not move when the angle between the A phase axis and the rotor (2) magnetic field axis becomes 0°.
  • the speed controller stops the rotor axial reference current (Idref) when the rotor axial reference current (Idref) comes to a selected highest rotor axial reference current (Idref) value.
  • the rotor (2) is aligned with the A phase axis.
  • the Permanent Magnet Synchronous Motor (PMSM) (1) can be operated by accepting the A phase axis as 0° for the rotor (2) position.
  • multi-channel incremental angle encoder is used.
  • the rotor axis (d) is in a position between 0° to 180° relative to the A phase axis at the start (when the rotor is at zero speed, in other words before rotor axial reference current (Idref) is given to the stator (3) reels)
  • the rotor (2) speed is measured with negative (-) sign by the incremental angle encoder after rotor axial reference current (Idref) is given.
  • the speed controller continuously increases the rotor axial reference current (Idref) in order to bring the rotor (2) speed to the selected rotor (2) speed.
  • the rotor (2) speed increases to high speeds with negative (-) sign.
  • the rotor (2) moves towards the A phase axis at high speed with negative sign, and it is aligned with A phase axis by oscillating in an uncontrolled way.
  • the sign of the selected rotor (2) speed which is considered as reference by the speed controller is changed as negative (-). Therefore, alignment is performed in a controlled way without oscillation at a speed as much as the selected rotor (2) speed.
  • the rotor (2) alignment method carries out alignment process in a controlled way without oscillation.
  • the initial position of the rotor (2) not changing, in other words continuously being measured as zero (0) depends on two situations.
  • the first situation is that the initial position of the rotor (2) (when the rotor (2) is immobile, the position of the rotor (2) axis before rotor axial reference current (Idref) is given) is right on the A phase axis (the angle between the rotor (2) axis and the A phase axis is 0°).
  • PMSM Permanent Magnet Synchronous Motor
  • the second situation is that the initial position of the rotor (2) (when the rotor (2) is immobile, the position of the rotor (2) axis before rotor axial reference current (Idref) is given) has 180° to the A phase axis (the rotor axis (d) is at -A phase axis, see Figure 1).
  • a vertical axial reference current to the rotor (2) (Iqref) is preferably given for a chosen time to the stator (3) reels when the rotor (2) speed is constantly measured as zero (0) (when the rotor (2) initial position does not change) even though rotor axial reference current (Idref) is given to the stator (3) reels and highest rotor axial reference current (Idref) value is reached; and thus it is enabled that the rotor (2) position changes.
  • the rotor (2) alignment method is applied after the vertical axial reference current to the rotor (2) (Iqref) given to the stator (3) reels are stopped.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

The present invention relates to a rotor (2) alignment method which enables the rotor (2) to be aligned with the A phase axis for Permanent Magnet Synchronous Motors (PMSM) (1) using incremental angle encoder, and which comprises the steps of giving rotor axial reference current (Idref) to the stator (3) reels such that it will generate magnetic field in A phase axis of the stator (3) by accepting the rotor angle (Θ) as 0, an incremental angle encoder measuring the speed of the rotor (2) continuously or in selected time intervals, a speed controller decreasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below a selected rotor (2) speed, stopping the rotor axial reference current (Idref) when the rotor axial reference current (Idref) comes to a selected highest rotor axial reference current (Idref) value.

Description

A ROTOR ALIGNMENT METHOD Field of the Invention
The present invention relates to a rotor alignment method wherein Permanent Magnet Synchronous Motors (PMSM) are aligned with a phase axis of a stator. Background of the Art
Today, high performance and high efficiency motors are needed for various applications. Permanent Magnet Synchronous Motor (PMSM) is preferred for meeting the said requirement. It is required to properly operate the PMSMs, be able to perform torque control, and be controlled by a controller in order to perform serial acceleration and deceleration. Field Oriented Control (FOC) is one of the main methods used for controlling PMSMs [K.Xu, W.Chen, Y,Xu,M.Gao, Z.He "Vector Control for PMSM," IFSA Sensors & Transducers, Vol. 170, pp. 227-233, 2014]. The position of PMSM rotor relative to the stator should be known in order to use the FOC method.
After the rotor is activated, the position of the rotor relative to the stator can be calculated by using the back-emf which occurs. However, since back-emf will not occur when the rotor is at the start (rotor at zero speed), it is not possible to calculate the position of the rotor relative to the stator with the help of back-emf. For this reason, the initial position of the rotor relative to the stator is generally performed with absolute positions sensors (absolute encoder, resolver) to be placed on the PMSMs, or a relative position sensors (encoders) (Incremental angle encoder). Even if the initial value of the rotor angle is known with the absolute encoders, they cause size and weight limitations and increase in costs in PMSM systems. Therefore, generally relative position sensors, in particular incremental angle encoders, are used in the applications. However, since the incremental angle encoders measure the change in the position, the relative position, the initial position of the rotor cannot be known completely when incremental angle encoder is used. The initial position is given as 0° in the incremental angle encoder, and the position of the rotor relative to this initial position can be determined with the incremental angle encoder. Therefore, in case the incremental angle encoder is used, the initial position of the rotor should be determined or the rotor should be brought to a known position in order to form a reference point. The most common one of the methods carried out for bringing the rotor to a known position is to form a magnetic field on A phase axis as a result of the stator current vector (Is) being formed on the A phase vector of the stator, and the said magnetic field aligning with the A phase axis of the rotor as a result of interaction with the magnetic field of the rotor, which is called as alignment. In this case, the rotor angle (Θ) is positioned such that it will be 0° with the A phase axis, and thus the position of the rotor relative to the stator is determined. In order that the stator current vector (Is) is on the A phase axis, the method of applying Vi(100) vector shown in Figure 3 can be performed. However, various alignment errors occur in the said method. In the beginning, if the rotor is in a position too close to the A phase, the Vi(100) vector or the applied stator current may not be able to move the rotor. In this case, even though the actual rotor angle (Θ) has a different value from 0° with the A phase axis, the rotor angle (Θ) will be considered as 0°. This difference causes errors during motor control, and also causes decrease in torque value of the motor. In order to eliminate this problem, the 6 vectors shown in Figure 3 are applied in turn, therefore the method of aligning the rotor with A phase by rotating it electrically one cycle is applied [H.Oh, K.Y.Song, K.Y.Cho,H.W.Kim,B. M.Han, "Initial Rotor Position Detecting Algorithm of PM Synchronous Motor using Incremental Encoder," IEEE, pp681-686, 2013]. In addition to the said method, the method of applying the V2(110) vector first and then the Vi(100) vector, thus aligning the rotor with the A phase may be applied [G.L.Cascella, F.Cupertino,L.Salvatore,S.Stasi "PMSM Rotor Double- Alignment by PI and Sliding-Mode Controllers," IEEE, ppl741-1747, 2003]. When the said methods are used, the size and application time of the applied vector becomes important. If the vector is not large enough, the rotor does not move. If the vector is larger than it is required, the rotor makes an uncontrolled sudden movement. Furthermore, since the torque value that will move the rotor changes depending on the environmental conditions directly such as temperature, expansion as a result of temperature change, friction; the required torque value to be applied varies dynamically. Depending on the inertia of the moved system, the sudden movement may damage the PMSM system or may cause an unwanted oscillation. During this oscillation movement, the rotor may be hung on an axis other than the phase axis. In addition to this, the vector should be applied until the oscillation made by the rotor around the A phase ends in order to completely the alignment properly. The time passing for the oscillation to end causes time loss in the alignment. The said time loss causes PMSMs with the incremental angle encoder not to be used in critical application wherein the credibility should be in high levels.
Summary of the Invention The objective of the present invention is to provide a method for bringing the rotor to a a known position relative to the stator when the rotor is at zero speed at the start for Permanent Magnet Synchronous Motors (PMSM) using incremental angle encoder. Detailed Description of the Invention
In order to better understand at least one exemplary embodiment of a rotor alignment method developed in order to fulfil the objective of the present invention, the embodiment is illustrated in the accompanying figures, and the details of the invention are to be evaluated by considering the whole description. In these figures; Figure 1 is the schematic view of the vector structures used in Field Oriented Control (FOC) of the Permanent Magnet Synchronous Motor (PMSM) in an exemplary embodiment of the invention.
Figure 2 shows the currents applied according to D-Q axis set in an exemplary embodiment of the invention.
Figure 3 shows the current vectors that can apply on the Permanent Magnet Synchronous Motor (PMSM) in an exemplary embodiment of the invention.
The components shown in the figures are each given reference numbers as follows:
1. Permanent Magnet Synchronous Motor (PMSM)
2. Rotor
3. Stator d. Rotor axis
q. Vertical axis to rotor
Is. Stator current vector
Isd. The component of the stator current vector in rotor axis
Isq. The component of the stator current vector vertical to rotor axis
A, B, C, A', B', C. Stator phases
S, N. Rotor magnetic poles
a, b, c. Triaxial coordinate plane axes
α, β. Two axes formed as a result of Clarke Cycle of triaxial (a, b, c) stator current isp. The component of the stator current in β axis
isa. The component of the stator current in a axis
Ψΐί. rotor flux
Θ. rotor angle
Id. rotor axial current Iq. vertical axial current to the rotor
Φ. The angle between the stator flux vector and the rotor flux vector
Idref. rotor axial reference current
Iqref. Vertical axial reference current to the rotor
Uo. The component of the current applied on the stator in a axis
Up. The component of the current applied on the stator in β axis
Vo(OOO), Vi(100), V2(110), V3(010), V4(011), Vs(OOl), V6(101), V7(lll).
PMSMs
A rotor (2) alignment method, which enables the rotor (2) to be aligned with the A phase axis at the start for Permanent Magnet Synchronous Motors (PMSM) (1) using incremental angle encoder, comprises the steps of
applying a rotor axial reference current (Idref) to the stator (3) reels such that magnetic field will be generated in A phase axis of the stator (3);
an incremental angle encoder measuring the speed of the rotor (2) continuously or in selected time intervals;
a speed controller decreasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below a selected rotor (2) speed;
stopping the rotor axial reference current (Idref) when the rotor axial reference current (Idref) comes to a selected highest rotor axial reference current (Idref) value;
giving a vertical axial reference current to the rotor (2) (Iqref) for a chosen time to the stator (3) reels when the rotor (2) speed is constantly measured as zero (0) even though rotor axial reference current (Idref) is given to the stator (3) reels and highest rotor axial reference current (Idref) value is reached;
- changing the selected rotor (2) speed sign as negative (-) if the rotor (2) speed measured by the angle encoder has negative (-) sign; operating Permanent Magnet Synchronous Motor (PMSM) (1) by accepting the A phase axis of the angle encoder as 0° for the rotor (2) position.
In a Permanent Magnet Synchronous Motors (PMSM) (1) wherein the rotor (2) is aligned with A phase axis at the start; it comprises
at least one speed controller applying a rotor axial reference current (Idref) to the stator (3) reels such that magnetic field will be generated in A phase axis of the stator (3);
an incremental angle encoder measuring the speed of the rotor (2) continuously or in selected time intervals;
speed controller decreasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below a selected rotor (2) speed, stopping the rotor axial reference current (Idref) when the rotor axial reference current (Idref) comes to a selected highest rotor axial reference current (Idref) value; giving a vertical axial reference current to the rotor (2) (Iqref) for a chosen time to the stator (3) reels when the rotor (2) speed is constantly measured as zero (0) even though rotor axial reference current (Idref) is given to the stator (3) reels and highest rotor axial reference current (Idref) value is reached, changing the selected rotor (2) speed sign as negative (-) if the rotor (2) speed measured by the angle encoder has negative (-) sign;
Permanent Magnet Synchronous Motor (PMSM) (1) operating by accepting the A phase axis of the angle encoder as 0° for the rotor (2) position.
In the inventive rotor (2) alignment method for Permanent Magnet Synchronous Motors (PMSM) using incremental angle encoder, initially (when the rotor is at zero speed), the rotor (2) (the movable part, component) is brought to a position selected relative to the stator (3). More specifically, the rotor axis (d) is aligned with the A phase axis of the stator (3) in the rotor (2) alignment method.
In the present invention, the output of a speed controlled preferably in a Field Oriented Control (FOC) algorithm is considered as rotor axial reference current (Idref) instead of vertical axial reference current to the rotor (Iqref), being different from the classis method. Vertical axial reference current to the rotor (Iqref) is considered as zero (0). First, a rotor axial reference current (Idref) is given to the stator (3) reels by considering the rotor angle (Θ) (rotor position information in terms of angle) 0 such that magnetic field will be generated in A phase axis of the stator (3). The magnetic field in the A phase axis generated with the rotor axial reference current (Idref) interacts with the magnetic field of the rotor (2), and applies a force and torque on the rotor (2) in direction of the A phase axis. The rotor (2) moves towards the A phase axis as a result of the applied torque.
The torque value generated on the rotor (2) depends on the angle between the A phase axis and the rotor axis (d) (the axis of the rotor (2) magnetic field) and the rotor axial reference current (Idref). In a position wherein the A phase axis and the rotor axis (d) are vertical to each other, the torque value generated on the rotor (2) is at the highest level, in the position wherein they are parallel to the each other (the angle between the A phase axis and the rotor axis is 0° or 180°) the torque value generated on the rotor (2) is zero (0). During alignment process, as the rotor (2) rotates (moves), the angle between the A phase axis and the rotor axis (d) changes. Therefore, the torque value generated in a reference current with constant rotor axis (Idref) can decrease and increase according to the varying angle. According to the said variant torque value, the rotor (2) speed changes during alignment process. The said variance in the speed causes the alignment process to take longer time and/or the oscillation of the rotor (2) in A phase axis. In the inventive rotor (2) alignment method, the alignment time is shortened by changing the rotor axial reference current (Idref) applied such that the rotor (2) speed will be fixed.
An incremental angle encoder measures the speed of the rotor (2) continuously or in selected time intervals. A speed controller increases or decreases rotor axial reference current (Idref) so that the rotor (2) speed remains at a selected rotor speed value. The speed controller decreases the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increases the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below a selected rotor (2) speed. Therefore, the rotor (2) moves towards the A phase axis of the stator (3) at a selected rotor (2) speed by rotating. The selected rotor (2) speed is preferably selected at the highest level at which the rotor (2) will not make oscillation. Since the torque value that will move the rotor (2) changes depending on the environmental conditions directly such as temperature, expansion as a result of temperature change, friction; the required torque value to be applied varies dynamically. In the inventive rotor (2) alignment method, since the alignment control is performed independent from the torque value, depending on the rotor (2) speed; the alignment time is not affected by the said dynamic variants. As a result of the rotor (2) moving much faster than desired; with the rotor (2) alignment method, the time losses that can causes by the oscillation in A phase axis and the effects causes by the dynamic variants are eliminated, and thus the alignment process is carried out much faster relative to the previous technique. When the rotor (2) speed reaches zero (0) value, the angle between the A phase axis and the rotor axis (d) becomes 0° and the rotor (2) is aligned with the A phase axis. In order to reach the selected rotor (2) speed, the speed controller starts to continuously increase the rotor axial reference current (Idref), however the torque cannot be generated and the rotor (2) does not move when the angle between the A phase axis and the rotor (2) magnetic field axis becomes 0°. The speed controller stops the rotor axial reference current (Idref) when the rotor axial reference current (Idref) comes to a selected highest rotor axial reference current (Idref) value. The rotor (2) is aligned with the A phase axis.
After the rotor (2) is aligned with the A phase axis, the Permanent Magnet Synchronous Motor (PMSM) (1) can be operated by accepting the A phase axis as 0° for the rotor (2) position.
In one embodiment of the invention, multi-channel incremental angle encoder is used. In this embodiment of the invention, if the rotor axis (d) is in a position between 0° to 180° relative to the A phase axis at the start (when the rotor is at zero speed, in other words before rotor axial reference current (Idref) is given to the stator (3) reels), the rotor (2) speed is measured with negative (-) sign by the incremental angle encoder after rotor axial reference current (Idref) is given. The speed controller continuously increases the rotor axial reference current (Idref) in order to bring the rotor (2) speed to the selected rotor (2) speed. As the rotor axial reference current (Idref) increases, the rotor (2) speed increases to high speeds with negative (-) sign. The rotor (2) moves towards the A phase axis at high speed with negative sign, and it is aligned with A phase axis by oscillating in an uncontrolled way. In order to avoid the said uncontrolled alignment, when a rotor speed with negative (-) sign is measured by the incremental angle encoder, the sign of the selected rotor (2) speed which is considered as reference by the speed controller is changed as negative (-). Therefore, alignment is performed in a controlled way without oscillation at a speed as much as the selected rotor (2) speed. In one embodiment of the invention, if the rotor axis (d) is in a position between 180° to 360° relative to the A phase axis at the start before rotor axial reference current (Idref) is given to the stator (3) reels, the rotor (2) speed is measured with positive (+) sign by the incremental angle encoder after rotor axial reference current (Idref) is given. In the said situation, the rotor (2) alignment method carries out alignment process in a controlled way without oscillation. In the present invention, even though rotor axial reference current (Idref) is given to the stator (3) reels and the highest rotor axial reference current (Idref) is reached at the start, the initial position of the rotor (2) not changing, in other words continuously being measured as zero (0) depends on two situations. The first situation is that the initial position of the rotor (2) (when the rotor (2) is immobile, the position of the rotor (2) axis before rotor axial reference current (Idref) is given) is right on the A phase axis (the angle between the rotor (2) axis and the A phase axis is 0°). In the first situation, since the rotor (2) is already aligned with the A phase axis, an alignment process is not needed. Permanent Magnet Synchronous Motor (PMSM) (1) can be operated by accepting the A phase axis as 0° for the rotor (2) position. The second situation is that the initial position of the rotor (2) (when the rotor (2) is immobile, the position of the rotor (2) axis before rotor axial reference current (Idref) is given) has 180° to the A phase axis (the rotor axis (d) is at -A phase axis, see Figure 1). In the second situation, assuming the rotor (2) is in the first situation, since the rotor (2) position is 180° erroneous if the Permanent Magnet Synchronous Motor (PMSM) (1) is operated, the Permanent Magnet Synchronous Motor (PMSM) (1) will not work properly. It is not known whether the rotor (2) is aligned in the A phase axis or in -A phase axis by not being able to recognizing these two situations in which the initial position of the rotor (2) does not change. In order to solve this problem, at the start, a vertical axial reference current to the rotor (2) (Iqref) is preferably given for a chosen time to the stator (3) reels when the rotor (2) speed is constantly measured as zero (0) (when the rotor (2) initial position does not change) even though rotor axial reference current (Idref) is given to the stator (3) reels and highest rotor axial reference current (Idref) value is reached; and thus it is enabled that the rotor (2) position changes. The rotor (2) alignment method is applied after the vertical axial reference current to the rotor (2) (Iqref) given to the stator (3) reels are stopped.

Claims

A rotor (2) alignment method, which enables the rotor (2) to be aligned with the A phase axis for Permanent Magnet Synchronous Motors (PMSM) (1) using incremental angle encoder, comprising the steps of
applying a rotor axial reference current (Idref) to the stator (3) reels such that magnetic field will be generated in A phase axis of the stator (3); an incremental angle encoder measuring the speed of the rotor (2) continuously or in selected time intervals;
a speed controller decreasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below a selected rotor (2) speed;
stopping the rotor axial reference current (Idref) when the rotor axial reference current (Idref) comes to a selected highest rotor axial reference current (Idref) value.
A rotor (2) alignment method according to claim 1, comprising the steps of - giving a vertical axial reference current to the rotor (2) (Iqref) for a chosen time to the stator (3) reels when the rotor (2) speed is constantly measured as zero (0) even though rotor axial reference current (Idref) is given to the stator (3) reels and highest rotor axial reference current (Idref) value is reached; applying a rotor axial reference current (Idref) to the stator (3) reels such that magnetic field will be generated in A phase axis of the stator (3);
an incremental angle encoder measuring the speed of the rotor (2) continuously or in selected time intervals;
a speed controller decreasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below a selected rotor (2) speed;
stopping the rotor axial reference current (Idref) when the rotor axial reference current (Idref) comes to a selected highest rotor axial reference current (Idref) value.
A rotor (2) alignment method according to claim 1 or 2, comprising the step of changing the sign of the selected rotor (2) speed as negative (-) if the rotor (2) speed first measured by the incremental angle encoder has negative (-) sign.
A rotor (2) alignment method according to any one of the preceding claims, comprising the step of operating Permanent Magnet Synchronous Motor (PMSM) (1) by accepting the A phase axis of the incremental angle encoder as 0° for the rotor (2) position.
A Permanent Magnet Synchronous Motor (PMSM) (1), comprising
at least one speed controller applying a rotor axial reference current (Idref) to the stator (3) reels such that magnetic field will be generated in A phase axis of the stator (3);
an incremental angle encoder measuring the speed of the rotor (2) continuously or in selected time intervals; and characterized by
speed controller decreasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder exceeds a selected rotor (2) speed, and increasing the rotor axial reference current (Idref) when the rotor (2) speed measured by the incremental angle encoder decreases below the said selected rotor (2) speed, stopping the rotor axial reference current (Idref) when the rotor axial reference current (Idref) comes to a selected highest rotor axial reference current (Idref) value. A Permanent Magnet Synchronous Motor (PMSM) (1) according to claim 5, comprising speed control giving a vertical axial reference current to the rotor (2) (Iqref) for a chosen time to the stator (3) reels when the rotor (2) speed is constantly measured as zero (0) even though rotor axial reference current (Idref) is given to the stator (3) reels and highest rotor axial reference current (Idref) value is reached.
A Permanent Magnet Synchronous Motor (PMSM) (1) according to claim 5 or 6, comprising speed controller changing the selected rotor (2) speed sign as negative (-) if the rotor (2) speed measured by the angle encoder has negative (-) sign.
A Permanent Magnet Synchronous Motor (PMSM) (1) according to any of the claims 5 to 8, which is operated as accepting the A phase axis as 0( rotor (2) position.
PCT/TR2016/050246 2016-07-28 2016-07-28 A rotor alignment method WO2018021983A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111987937A (en) * 2019-05-24 2020-11-24 上海安浦鸣志自动化设备有限公司 Permanent magnet motor starting device and method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0784378A2 (en) * 1996-01-11 1997-07-16 Siemens Aktiengesellschaft Method for determining the absolute rotor position of in field controlled synchronous machines and device for carrying out this method
US20080272731A1 (en) * 2007-05-03 2008-11-06 Schulz Steven E Method and system for resolver alignment in electric motor system
US20150214875A1 (en) * 2012-08-10 2015-07-30 Hitachi Automotive Systems, Ltd. Motor Control Device Provided with Motor Unit and Inverter Unit
US20160061635A1 (en) * 2013-05-28 2016-03-03 Fuji Electric Co., Ltd. Magnetic pole position detection device of permanent magnet-type synchronous motor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0784378A2 (en) * 1996-01-11 1997-07-16 Siemens Aktiengesellschaft Method for determining the absolute rotor position of in field controlled synchronous machines and device for carrying out this method
US20080272731A1 (en) * 2007-05-03 2008-11-06 Schulz Steven E Method and system for resolver alignment in electric motor system
US20150214875A1 (en) * 2012-08-10 2015-07-30 Hitachi Automotive Systems, Ltd. Motor Control Device Provided with Motor Unit and Inverter Unit
US20160061635A1 (en) * 2013-05-28 2016-03-03 Fuji Electric Co., Ltd. Magnetic pole position detection device of permanent magnet-type synchronous motor

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
G.L.CASCELLA; F.CUPERTINO; L.SALVATORE; S.STASI: "PMSM Rotor Double-Alignment by PI and Sliding-Mode Controllers", IEEE, 2003, pages L741 - 1747
H.OH; K.Y.SONG; K.Y.CHO; H.W.KIM; B.M.HAN: "Initial Rotor Position Detecting Algorithm of PM Synchronous Motor using Incremental Encoder", IEEE, 2013, pages 681 - 686, XP032475403, DOI: doi:10.1109/ECCE-Asia.2013.6579174
K.XU, W.CHEN; Y,XU,M.GAO; Z.HE: "Vector Control for PMSM", IFSA SENSORS & TRANSDUCERS, vol. 170, 2014, pages 227 - 233

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111987937A (en) * 2019-05-24 2020-11-24 上海安浦鸣志自动化设备有限公司 Permanent magnet motor starting device and method
CN111987937B (en) * 2019-05-24 2023-11-03 上海安浦鸣志自动化设备有限公司 Permanent magnet motor starting device and method

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