Control device for electric motor and control method for electric motor
First Claim
1. A control device configured to control an electric motor by vector control, the control device comprising:
- a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity for voltage being calculated from a torque command value used to drive the electric motor; and
an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, wherein the at least one state quantity for control includes an inductance value of the current control unit and an inductance value of the electric motor, and (ii) drive the electric motor on the basis of a result of the determination,wherein the over-modulation processing unit includes;
an over-modulation characteristic determination unit configured to determine which type of over-modulation stability the electric motor is in while in the over-modulation state, from at least two types of over-modulation stability, on the basis of the inductance value of the current control unit and the inductance value of the electric motor; and
a phase region determination unit configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, according to the type of over-modulation stability the electric motor is in, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not.
1 Assignment
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Accused Products
Abstract
A control device 1 for an electric motor of the present invention includes: a current control unit 4 configured to calculate voltage command values vd*, vq* used to drive an electric motor 100, on the basis of a state quantity for voltage command value calculation and q and d-axis current detection values id, iq, the state quantity calculated from a torque command value T*; and an over-modulation processing unit 16 configured to determine whether the electric motor 100 is stable or unstable in an over-modulation state, on the basis of the voltage command values vd*, vq*, current control constants, and electric motor constants, and to drive the electric motor 100 in the over-modulation state when determining that the electric motor 100 is stable.
15 Citations
28 Claims
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1. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity for voltage being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, wherein the at least one state quantity for control includes an inductance value of the current control unit and an inductance value of the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit includes; an over-modulation characteristic determination unit configured to determine which type of over-modulation stability the electric motor is in while in the over-modulation state, from at least two types of over-modulation stability, on the basis of the inductance value of the current control unit and the inductance value of the electric motor; and a phase region determination unit configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, according to the type of over-modulation stability the electric motor is in, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A control method for controlling an electric motor by vector control, the method comprising:
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calculating a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity for voltage being calculated from a torque command value used to drive the electric motor; and determining whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, wherein the at least one state quantity for control includes an inductance value of a current control unit and an inductance value of the electric motor; and driving the electric motor on the basis of a result of the determination, wherein the step of determining whether the electric motor is stable or unstable in the over-modulation state, on the basis of the phase of the voltage command value and the at least one state quantity for control which is used to control the electric motor includes; determining which type of over-modulation stability the electric motor is in while in the over-modulation state, from at least two types of over-modulation stability, on the basis of the inductance value of the current control unit and the inductance value of the electric motor; identifying a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, according to the type of over-modulation stability the electric motor is in, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction; determining whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not.
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20. A control device configured to control an electric motor by vector control, the control device comprising:
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current control means for calculating a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity for voltage being calculated from a torque command value used to drive the electric motor; and over-modulation processing means for (i) determining whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, wherein the at least one state quantity for control includes an inductance value of the current control means and an inductance value of the electric motor, and (ii) driving the electric motor on the basis of a result of the determination, wherein the over-modulation processing means includes; over-modulation characteristic determination means for determining which type of over-modulation stability the electric motor is in while in the over-modulation state, from at least two types of over-modulation stability, on the basis of the inductance value of the current control means and the inductance value of the electric motor; and phase region determination means for (i) identifying a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, according to the type of over-modulation stability the electric motor is in on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determining whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not.
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21. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit is configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not, and wherein the over-modulation processing unit is configured such that, when determining whether the electric motor is stable or unstable in the over-modulation state, the over-modulation processing unit determines that a state of the electric motor changes to a stable or unstable state every time the phase of the voltage command value moves to a different quadrant on the coordinate system defined in the magnetic pole direction and the direction orthogonal to the magnetic pole direction.
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22. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit is configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not, wherein the over-modulation processing unit further includes an over-modulation suppressing unit configured to reduce a modulation ratio when the electric motor is determined to be unstable in the over-modulation state, and wherein the over-modulation suppressing unit is configured such that the over-modulation suppressing unit does not reduce the modulation ratio when the modulation ratio of the electric motor is within a preset threshold.
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23. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit is configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not, and wherein the over-modulation processing unit stores an inductance value of the current control unit for each of at least two types of over-modulation stability, and selects one of the inductance values of the current control unit according to the phase of the voltage command value.
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24. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit is configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not, wherein the electric motor is connected to a transmission, and wherein the over-modulation processing unit is configured such that, when the electric motor is unstable in the over-modulation state, the over-modulation processing unit moves the phase of the voltage command value to a phase region in which the electric motor is stable in the over-modulation state, by causing the transmission to perform a gear-shift.
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25. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit is configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not, wherein the electric motor is connected to a drive force transmission mechanism capable of switching a transmission direction of a drive force, and wherein the over-modulation processing unit is configured such that, when the electric motor is unstable in the over-modulation state, the over-modulation processing unit moves the phase of the voltage command value to a phase region in which the electric motor is stable in the over-modulation state, by switching the transmission direction of the drive force.
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26. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit is configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not, wherein the electric motor is a power generator, and wherein the over-modulation processing unit is configured such that, when the power generator is unstable in the over-modulation state, the over-modulation processing unit moves the phase of the voltage command value to a phase region in which the electric motor is stable in the over-modulation state, by moving an operation point of the electric motor, representing a power generation amount and a number of revolutions of the power generator, along an even output line of a graphical representation of a relationship between a power generation amount and the number of revolutions of the power generator, the even output line being a line on the graphical representation at which an output of the electric motor is constant.
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27. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit is configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not, wherein the state quantity for control includes a set of current control constants used by the current control unit to control the electric motor, wherein the over-modulation processing unit is configured to store the current control constants, select a current control constant at which the electric motor is stable in the over-modulation state, on the basis of the phase of the voltage command value, and output the selected current control constant to the current control unit, wherein the over-modulation processing unit is configured to store the current control constant for each of at least two types of over-modulation stability, determine that the electric motor is in the over-modulation state when a modulation ratio of the electric motor is equal to or larger than a predetermined value, and select the current control constant of the type of over-modulation stability, among the at least two types of over-modulation stability, at which the electric motor is stable, on the basis of the phase of the voltage command value, and wherein the over-modulation processing unit is configured to store the current control constant corresponding to a position at a boundary between the at least two types of over-modulation stability, and select the current control constant corresponding to the position at the boundary when the modulation ratio of the electric motor is smaller than the predetermined value.
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28. A control device configured to control an electric motor by vector control, the control device comprising:
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a current control unit configured to calculate a voltage command value used to drive the electric motor, on the basis of a state quantity for voltage command value calculation and a current detection value detected from the electric motor, the state quantity being calculated from a torque command value used to drive the electric motor; and an over-modulation processing unit configured to (i) determine whether the electric motor is stable or unstable in an over-modulation state, on the basis of a phase of the voltage command value and at least one state quantity for control which is used to control the electric motor, and (ii) drive the electric motor on the basis of a result of the determination, wherein the over-modulation processing unit is configured to (i) identify a stable phase region of the voltage command value in which the electric motor is stable in the over-modulation state, on the basis of quadrants on a coordinate system defined in a magnetic pole direction and a direction orthogonal to the magnetic pole direction, and (ii) determine whether the electric motor is stable or unstable in the over-modulation state, on the basis of whether the phase of the voltage command value is in the stable phase region or not, wherein the state quantity for control includes a set of current control constants used by the current control unit to control the electric motor, wherein the over-modulation processing unit is configured to store the current control constants, select a current control constant at which the electric motor is stable in the over-modulation state, on the basis of the phase of the voltage command value, and output the selected current control constant to the current control unit, and wherein the over-modulation processing unit is configured to continuously change the current control constants, according to the phase of the voltage command value.
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Specification