JP6676396B2 - Motor driving device and industrial machine using the same - Google Patents

Description

  The present invention relates to a motor driving device.

  Motor control requires information about the mechanical state (number of rotations and position) of the motor. Motor control systems are broadly divided into those that use sensors such as resolvers and those that do not use sensors (sensorless systems). In the sensorless method, a mechanical state of the motor is estimated based on an electrical state such as a voltage and a current applied to the motor, and drive control of the motor is performed based on the estimated state.

JP 2001-211698 A

Yoji Takeda et al., “Design and Control of Interior Permanent Magnet Synchronous Motor,” Ohmsha, October 2001, pp. 113-115

  In a conventional technique (for example, see Non-Patent Document 1), a detection voltage is input to a motor and a detection current is used as an output of the motor to estimate a phase angle (position) from an input / output relationship. , On the assumption that the detection voltage is constant. However, if a constant voltage is output, the motor rotates during the sampling period, and the voltage phase angle is delayed by the rotation angle, so that the voltage input to the motor is not constant, and its effective value and the detected voltage Error occurs between the two. Therefore, an error occurs in the estimated phase angle due to the voltage error, and the estimation accuracy deteriorates. If the sampling period is sufficiently short, this error is small and can be neglected. However, the influence of the error increases as the sampling frequency becomes relatively lower with respect to the rotation speed of the motor.

  The present invention has been made in such a situation, and an exemplary object of one embodiment of the present invention is to provide a sensorless motor driving device with improved estimation accuracy of a motor state.

  One embodiment of the present invention relates to a motor driving device. The drive device monitors a voltage applied to the motor and generates a detection voltage vector at a predetermined sampling period Ts, and a current detection unit monitors a current flowing through the motor and generates a detection current vector. , Ts / 2, assuming that the motor rotates, the phase of the detection voltage vector is rotated, and a voltage phase correction unit that generates a correction voltage vector; and the rotation speed of the motor based on the correction voltage vector and the detection current vector. And a motor controller that generates a control signal so that the estimated value ＾ ω of the rotation speed of the motor approaches the target rotation speed of the motor, and a power unit that drives the motor based on the control signal. Is provided.

  According to this aspect, the accuracy of estimating the state of the motor can be improved by using the correction voltage vector representing the detected voltage closer to the effective voltage (vector).

  The voltage phase correction unit may rotate the angle corresponding to Δω · Ts / 2, or the voltage phase angle of the detection voltage vector.

  The estimator may generate a predicted current vector based on the corrected voltage vector and the detected current vector, and estimate the rotor phase angle ＾ θ based on a difference between the predicted current vector and the detected current vector.

  The voltage detection unit may include a voltage sensor that generates a detection voltage of the uvw phase, and a first coordinate converter that converts the detection voltage of the uvw coordinate system into a voltage vector of the γδ coordinate system.

  The drive device may further include a current phase correction unit that rotates the detection current vector and generates a correction current vector, assuming that the motor rotates for a time period of Ts / 2. The estimator may estimate the rotation speed of the motor based on the correction voltage vector and the correction current vector.

  The current detection unit may include a current sensor that generates a detection current of the uvw phase, and a second coordinate converter that converts the detection current of the uvw coordinate system into a current vector of the γδ coordinate system.

  Another embodiment of the present invention relates to an industrial machine. The industrial machine includes a permanent magnet motor and any one of the above-described driving devices that drives the permanent magnet motor.

  It should be noted that any combination of the above-described components, and any replacement of the components and expressions of the present invention between methods, apparatuses, systems, and the like are also effective as embodiments of the present invention.

  According to an embodiment of the present invention, the accuracy of estimating the mechanical state of the motor can be improved.

It is a block diagram of a motor drive device concerning an embodiment. 2 (a) is a waveform of the d-axis voltage _{v d,} FIG. 2 (b) is a diagram showing a dq coordinate system and the γδ coordinate system. FIG. 4 is a diagram illustrating correction of a voltage phase angle. It is a block diagram which shows the example of a structure of an estimator. FIG. 3 is a block diagram illustrating a specific configuration example of a motor drive device. 6A and 6B are operation waveform diagrams of the motor drive device of FIG. It is a block diagram of a motor drive device concerning a modification. FIG. 1 is a perspective view illustrating an appearance of a shovel as an example of a construction machine according to an embodiment. It is a block diagram of an electric system, a hydraulic system, and the like of the shovel according to the embodiment.

  Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and the repeated description will be omitted as appropriate. In addition, the embodiments do not limit the invention, but are exemplifications, and all features and combinations described in the embodiments are not necessarily essential to the invention.

  In this specification, “the state in which the member A is connected to the member B” means that the member A and the member B are physically directly connected, and that the member A and the member B It does not substantially affect the actual connection state, or does not impair the function or effect exerted by the combination thereof, and also includes the case where the connection is made indirectly via another member. Similarly, “the state in which the member C is provided between the member A and the member B” means that the member A and the member C or the member B and the member C are directly connected, Indirect connection via another member that does not substantially affect the actual connection state or impair the function or effect provided by the combination thereof.

  FIG. 1 is a block diagram of a motor drive device 100 according to the embodiment. The motor driving device 100 drives a permanent magnet motor (hereinafter, simply referred to as a motor) 200. The motor drive device 100 performs feedback control of the motor 200 by a sensorless method so that the rotation speed ω of the motor 200 approaches its target value (target rotation speed) ω *.

  The motor driving device 100 includes a voltage detection unit 110, a current detection unit 120, a voltage phase correction unit 130, an estimator 140, a motor controller 160, and a power unit 180. In the present embodiment, motor 200 is a three-phase motor, and controls motor 200 by vector control using estimated rotational orthogonal two-phase coordinates (γδ axes).

The voltage detection unit 110 monitors the three-phase voltages v _u , v _v , v _w (collectively v _uvw ) applied to the motor 200, and detects the detection voltage vectors v _γ , v _δ (at a predetermined sampling period Ts). v _γδ ). Current detecting unit 120, the three-phase current _i u flowing through the motor _200, i _v, monitors i _{w (i} collectively referred _uvw), to produce a detected current vector i _γ, i δ _(i collectively referred to as _{the ??)} .

The voltage phase correction unit 130 rotates the electric phase angle of the detection voltage vector _vγδ assuming that the motor 200 rotates at a constant speed for a half period Ts / 2 of the sampling period Ts, and corrects the correction voltage vector _vγδ ′. Generate The estimator 140 estimates the mechanical state of the motor 200 (hereinafter referred to as the rotation speed ω) based on the correction voltage vector _vγδ ′ and the detected current vector _iγδ , and generates an estimated rotation speed value 回 転 ω. .

The motor controller 160 generates the control signal v _uvw * such that the estimated rotation speed _{回 転} ω of the motor 200 approaches the target rotation speed (rotation speed command value) ω * of the motor 200. The control signal v _uvw * is a command value for each of the U-phase, V-phase, and W-phase voltages. The power unit 180 drives the motor 200 based on the control signal v _uvw *. For example, power unit 180 includes a modulator that performs pulse width modulation on control signal v _uvw *, and an inverter that drives motor 200 based on the pulse width modulated signal.

In FIG. 2 (a), the waveform of the d-axis voltage _{v d} is shown. t _{0, t} 2, · · · are sampling points by the voltage detection unit 110, d-axis voltage _{v d} at each sampling point, the measured voltage v _gamma. The measured voltage v _gamma does not match the average value of d-axis voltage _{v d} of each sampling period (effective voltage _v d _bar), the error _{v err} occurs between them. FIG. 2B shows a dq coordinate system (synchronous rotation orthogonal two-phase coordinates) and a γδ coordinate system in an overlapping manner. The γδ axis coordinate system rotates clockwise at a speed ω with respect to the dq axis coordinate system. Δθ is the phase difference between the q axis and the δ axis at each time.

FIG. 3 is a diagram illustrating the correction of the voltage phase angle. The voltage phase correction unit 130 rotates (delays) the phase angle ω · Ts / 2 and the sampled voltage v (t ₀ ), assuming that the motor rotation speed ω is constant during each sampling period Ts. . Voltage after the rotation v _{'(t 0)} is close to the voltage _{v d} at time _{t 1} of FIG. 2 (a), that is, close to the effective voltage _v d _bar voltage _{v d.}

Return to FIG. The rotation speed Δω estimated by the estimator 140 is input to the voltage phase correction unit 130. Voltage phase correcting unit 130, ^ ω · Ts / 2 corresponding angle, by rotating the voltage phase angle of the detection voltage vector v _{the ??,} generates the correction voltage vector v _{the ??} '.

  The present invention extends to various devices and circuits that can be grasped as the block diagram or circuit diagram of FIG. 1 or derived from the above description, and is not limited to a specific configuration. Hereinafter, a more specific configuration example will be described, not to narrow the scope of the present invention, but to help understand and clarify the essence and circuit operation of the present invention.

FIG. 4 is a block diagram illustrating a configuration example of the estimator 140. The estimator 140 estimates the mechanical state of the motor (specifically, the position estimation value ＾ θ and the speed estimation value) based on the electric state of the motor (i _γ , i _δ , v _γ ′, v _δ ′). Value ＾ ω). Predicting current calculation unit 142, the correction voltage vector _{v γδ '(v γ',} v δ '), the current vector _{i γδ (i γ, i δ} ) and speed estimation value ^ omega, based on the induced voltage estimated value ^ e generates a predicted value of the current vector i _{the ??} (predicted current vector) _i γδ '. The phase angle estimator 144 generates a rotor position estimation value ＾ θ and a speed estimation value ＾ ω based on the predicted current vector i _γδ ′ (i _γ , i _δ ′).

The first error generator (subtractor) 150 generates a gamma-axis current error .DELTA.i _gamma corresponding to the difference between the current i measured value i _gamma and the predicted value i _gamma of _gamma '. The second error generator (subtractor) 151 generates a [delta]-axis current error .DELTA.i _[delta] corresponding to the difference between the current i measured value i _[delta] and the predicted value i _[delta] of _[delta] '. Position error estimator 152 generates a gamma-axis current error Δi error estimate position based on the _gamma delta ^ differential value of θ Δ ^ θ '(i.e. error estimate of the velocity). The induced voltage estimating unit 153 generates an estimated value ＾ e of the induced voltage based on the δ-axis current error Δi _δ . The coefficient unit (multiplier) 154 multiplies the estimated value 誘 起 e of the induced voltage by the induced voltage constant (1 / ＾ K _E ) to generate a predicted value of the speed. Adders 155 and 156 add the estimated speed value and the estimated error value to generate an estimated speed value Δω. The estimated speed ＾ ω is integrated by the integrator 157 to generate a position estimated value ＾ θ.

  Note that the configuration of the estimator 140 is not limited to that shown in FIG. 4, and other known or future technology related to sensorless driving can be used.

FIG. 5 is a block diagram illustrating a specific configuration example of the motor driving device 100. Voltage detector 110 includes a voltage sensor 112 and a first coordinate converter 114. The voltage sensor 112 generates a uvw-phase detection voltage v _uvw . The first coordinate converter 114 converts the detection voltage v _{uvw in the uvw} coordinate system into a voltage vector v _γδ in the γδ coordinate system. The current detection unit 120 includes a current sensor 122 and a second coordinate converter 124. The current sensor 122 generates a uvw-phase detection current i _uvw . The second coordinate converter 124 converts the detected current i _{uvw in the uvw} coordinate system into a current vector i _γδ in the γδ coordinate system.

The motor controller 160 performs a major loop that performs feedback control that brings the rotation speed ω of the motor 200 closer to its target value ω *, and a minor loop that performs feedback control that brings the current vector i _γδ of the motor 200 closer to its command vector i _γδ *. Have. The speed error detector 162 generates a speed error Δω which is a difference between the estimated value ＾ ω of the rotational speed and the target value ω *. Speed controller 164 generates current command vector i _γδ * based on speed error Δω. For example, the speed controller 164 can be constituted by a PI (proportional / integral) controller or a PID (proportional / integral / derivative) controller.

The current error detector 166 generates a current error Δi which is a difference between the detected current vector i _γδ and the command vector i _γδ *. The current controller 168 generates a voltage command vector v _γδ * based on the current error Δi. For example, the current controller 168 can be constituted by a PI (proportional / integral) controller or a PID (proportional / integral / derivative) controller. The third coordinate converter 170 converts the voltage command vector v _γδ * of the _γδ coordinate system into a voltage command vector v _uvw * of the uvw coordinate system. For the coordinate conversion by the coordinate converters 114, 124, and 170, the position estimation value ＾ θ estimated by the estimator 140 is used.

  The above is the configuration of the motor driving device 100. Subsequently, the operation will be described. FIGS. 6A and 6B are operation waveform diagrams when the load of the motor of the motor driving device 100 of FIG. 1 is changed in a step-like manner. The load changes at times t = 2s and 4s. FIGS. 6A and 6B show a position estimation error Δθ and an induced voltage error Δe, respectively. Each drawing shows a waveform when the voltage phase corrector 130 performs correction (with correction) and when no correction is performed (without correction).

  Referring to FIG. If no correction is made, the initial position may have an error, and even in a steady state, the error will have a non-zero baseline. If a load change occurs at time t = 2s, the error moves away from the baseline and returns to the original baseline at time t = 4s. Referring to FIG. 6B, when no correction is performed, the error Δe in the steady state becomes zero, but the error in the induced voltage increases due to the load fluctuation at time t = 2 s.

  In contrast, when the correction is performed, as shown in FIG. 6A, the position estimation error can be kept close to zero both in the steady state and when the load changes. Further, as shown in FIG. 6B, the error of the induced voltage can be maintained near zero regardless of the load fluctuation.

  The above is the operation of the motor driving device 100. As described above, according to the motor driving device 100, the position error and the induced voltage error can be reduced. This makes it possible to drive the motor more stably and more accurately than in the past.

  Referring to FIG. 1, functional blocks such as a voltage phase correction unit 130, an estimator 140, and a motor controller 160 are implemented by a combination of a processor such as a microcomputer or a CPU (Central Processing Unit) and a software program executed thereby. can do. Therefore, when the voltage phase correction unit 130 is implemented on software, it is not necessary to add hardware, so that the cost and the size of the device are not substantially increased.

  In the related art, in a situation where the sampling frequency is relatively low with respect to the rotation speed of the motor, the estimation error becomes particularly large. According to the motor driving device 100 according to the embodiment, the estimation error can be reduced when the same sampling frequency and the same rotation speed are assumed. Alternatively, when trying to obtain the same control performance as that of the related art, the sampling frequency can be lower than that of the related art. Alternatively, when the same control performance as that of the related art is to be obtained, the number of revolutions can be further increased at the same sampling frequency.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and that such modifications are also within the scope of the present invention. is there. Hereinafter, such modifications will be described.

FIG. 7 is a block diagram of a motor drive device 100a according to a modification. The motor driving device 100a further includes a current phase correction unit 190 in addition to the components of the motor driving device 100 of FIG. The current phase correction unit 190 rotates the detected current vector i _γδ assuming that the motor 200 rotates for a time period of Ts / 2, and generates a corrected current vector i _γδ ′. The estimator 140 estimates the rotation speed ω of the motor 200 based on the correction voltage vector _vγδ ′ and the correction current vector _iγδ ′. According to this modification, the accuracy can be further improved.

(Application)
Finally, the use of the motor drive device 100 will be described. The motor drive device 100 can be used for an industrial machine. FIG. 8 is a perspective view illustrating an external appearance of a shovel 1 which is an example of the industrial machine according to the embodiment. The shovel 1 mainly includes a traveling mechanism 2 and an upper revolving body (hereinafter, also simply referred to as a revolving body) 4 rotatably mounted on the upper part of the traveling mechanism 2 via a revolving mechanism 3.

  A boom 5, an arm 6 linked to the tip of the boom 5, and a bucket 10 linked to the tip of the arm 6 are attached to the revolving unit 4. The bucket 10 is a facility for capturing suspended loads such as earth and sand and steel materials. The boom 5, the arm 6, and the bucket 10 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, respectively. Further, the revolving unit 4 is provided with a power source such as an operator's cab 4a for accommodating an operator who operates the position of the bucket 10, the excitation operation and the release operation, and an engine 11 for generating hydraulic pressure. The engine 11 is, for example, a diesel engine.

  FIG. 9 is a block diagram of an electric system, a hydraulic system, and the like of the shovel 1 according to the embodiment. In FIG. 9, the system for mechanically transmitting power is indicated by a double line, the hydraulic system is indicated by a thick solid line, the control system is indicated by a broken line, and the electric system is indicated by a thin solid line.

  The shovel 1 includes a motor generator (also referred to as an electric motor) 12 and a speed reducer 13. The rotating shafts of the engine 11 and the motor generator 12 are connected to each other by being connected to an input shaft of the speed reducer 13. Have been. When the load of the engine 11 is large, the motor generator 12 assists (assists) the driving force of the engine 11 with its own driving force, and the driving force of the motor generator 12 is transmitted to the main pump 14 via the output shaft of the speed reducer 13. Is transmitted. On the other hand, when the load of the engine 11 is small, the driving force of the engine 11 is transmitted to the motor generator 12 via the speed reducer 13, so that the motor generator 12 generates power. The motor generator 12 is configured by, for example, an IPM (Interior Permanent Magnetic) motor in which a magnet is embedded inside the rotor. Switching between driving of the motor generator 12 and power generation is performed by the controller 30 that controls the driving of the electric system in the shovel 1 according to the load of the engine 11 and the like.

  A main pump 14 and a pilot pump 15 are connected to an output shaft of the speed reducer 13, and a control valve 17 is connected to the main pump 14 via a high-pressure hydraulic line 16. The control valve 17 is a device that controls a hydraulic system in the shovel 1. A boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 are connected to the control valve 17 via a high-pressure hydraulic line in addition to the hydraulic motors 2A and 2B for driving the traveling mechanism 2 shown in FIG. , The control valve 17 controls the hydraulic pressure supplied thereto in accordance with the operation input of the driver.

  An operating device 26 (operating means) is connected to the pilot pump 15 via a pilot line 25. The operating device 26 is an operating device for operating the turning electric motor 21, the traveling mechanism 2, the boom 5, the arm 6, and the bucket 10, and is operated by an operator. The control valve 17 is connected to the operating device 26 via a hydraulic line 27, and a pressure sensor 29 is connected via a hydraulic line 28. The operating device 26 converts the hydraulic pressure (primary hydraulic pressure) supplied through the pilot line 25 into a hydraulic pressure (secondary hydraulic pressure) corresponding to the operation amount of the operator and outputs the hydraulic pressure. The secondary-side hydraulic pressure output from the operating device 26 is supplied to the control valve 17 through a hydraulic line 27 and detected by a pressure sensor 29.

  When an operation for turning the turning mechanism 3 is input to the operation device 26, the pressure sensor 29 detects this operation amount as a change in the hydraulic pressure in the hydraulic line 28. The pressure sensor 29 outputs an electric signal indicating the oil pressure in the oil pressure line 28. This electric signal is input to the controller 30 and used for driving control of the turning electric motor 21.

  The controller 30 is configured by an arithmetic processing unit including a CPU (Central Processing Unit) and an internal memory, and is realized by the CPU executing a drive control program stored in the internal memory. The controller 30 performs drive control of the inverters 18A and 18C, the power storage means 40, and the like in response to various sensors and operation inputs from the operation device 26 and the like.

  The turning electric motor 21 is provided in the turning mechanism 3 in FIG. 8 and turns the upper turning body 4. The turning motor 21 is an AC motor, and is a power source of the turning mechanism 3 that turns the turning body 4. A resolver 22, a mechanical brake 23, and a turning speed reducer 24 are connected to a rotating shaft 21A of the turning electric motor 21. The turning inverter 18C receives electric power from the power storage means 40 and drives the turning electric motor 21. Further, during the regenerative operation of the turning electric motor 21, the electric power from the turning electric motor 21 is collected in the power storage means 40.

  When the turning electric motor 21 performs a power running operation, the turning force of the rotational driving force of the turning electric motor 21 is amplified by the turning speed reducer 24, and the turning body 4 is controlled to accelerate and decelerate to perform a rotary motion. In addition, due to the inertial rotation of the swing body 4, the rotation speed is increased by the swing reduction gear 24 and transmitted to the swing motor 21 to generate regenerative electric power.

  The resolver 22 is a sensor that detects the rotation position and the rotation angle of the rotation shaft 21A of the turning electric motor 21, and detects the rotation angle and the rotation direction of the rotation shaft 21A by being mechanically connected to the turning electric motor 21. When the resolver 22 detects the rotation angle of the rotation shaft 21A, the rotation angle and the rotation direction of the turning mechanism 3 are derived. The mechanical brake 23 is a braking device that generates a mechanical braking force, and mechanically stops the rotating shaft 21 </ b> A of the turning electric motor 21 according to a command from the controller 30. The turning speed reducer 24 is a speed reducing device that reduces the rotation speed of the rotation shaft 21 </ b> A of the turning electric motor 21 and mechanically transmits the rotation speed to the turning mechanism 3.

  Subsequently, the electric system will be described in detail. The electric system mainly includes a controller 30, power storage means 40, and inverters 18A and 18C.

(assist)
The motor generator 12 is connected to the secondary (output) end of the assist inverter 18A. The inverter 18A controls the operation of the motor generator 12 based on a command from an assist inverter controller which is a part of the controller 30.

(Turning)
The turning motor 21, the resolver 22, the mechanical brake 23, the turning speed reducer 24, the turning inverter 18 </ b> C, and the turning inverter controller which is a part of the controller 30 constitute an electric turning device.
The turning electric motor 21 is AC-driven by a turning inverter 18C according to a PWM (Pulse Width Modulation) control command. As the turning electric motor 21, for example, a magnet embedded type IPM motor is suitable.

  The turning inverter controller receives the rotation speed command according to the operation input, and controls the turning inverter 18C so that the turning speed of the turning electric motor 21 detected by the resolver 22 matches the rotation speed command.

(Power supply)
The power storage device 40 and a converter controller which is a part of the controller 30 constitute a power supply device. The power storage means 40 includes, for example, a battery which is a storage battery, a step-up / step-down converter (bidirectional DC / DC converter) for controlling charging / discharging of the battery, and a DC bus composed of positive and negative DC wirings (shown in the figure). Zu). As the battery, a rechargeable secondary battery such as a lithium ion battery, a capacitor, or another form of power supply capable of transmitting and receiving power may be used. The primary side (DC input) of each of the inverters 18A and 18C is connected to the DC bus. The controller controls the bidirectional DC / DC converter so that the DC link voltage generated on the DC bus is at a predetermined voltage level. The power supply device causes the bidirectional DC / DC converter to perform a step-up operation when the motor generator 12 or the like performs a power running operation, and performs a step-down operation of the bidirectional DC / DC converter when the motor generator 12 or the like performs a regenerative operation. Then, the electric power generated by the motor generator 12 is collected in the battery.

  That is, when the inverter 18A causes the motor generator 12 to perform a power running operation, necessary electric power is supplied from the battery and the buck-boost converter to the motor generator via the DC bus. When the motor generator 12 is operated for regenerative operation, the electric power generated by the motor generator 12 is charged to the battery via the DC bus and the step-up / step-down converter. The switching control between the step-up operation and the step-down operation of the step-up / step-down converter is performed by the converter controller based on the DC bus voltage value, the battery voltage value, and the battery current value. Thereby, the DC bus can be maintained in a state where the DC bus is charged to a predetermined constant voltage value. The above is the configuration of the shovel 1.

  The motor drive device 100 according to the embodiment can be used for driving the motor generator 12, and in this case, a part of the controller 30 and the inverter 18A correspond to the motor drive device 100.

  Alternatively, the motor driving device 100 according to the embodiment can be used for driving the turning electric motor 21, and in this case, a part of the controller 30 and the inverter 18 </ b> C correspond to the motor driving device 100. Since the motor drive device 100 can drive the motor in a sensorless manner, the resolver 22 in FIG. 9 may be omitted, or the detected value of the resolver 22 may be used to complement the position / velocity detected by the resolver 22. And the sensorless detection value may be used together.

  Here, in the embodiment, the shovel 1 has been described as an example of the industrial machine and the construction machine. However, other examples of the construction machine using the motor include a lifting magnet vehicle, a crane, and an electric forklift.

  Although the present invention has been described using specific words and phrases based on the embodiments, the embodiments are merely illustrative of the principles and applications of the present invention, and the embodiments are defined in the appended claims. Many modifications and changes in arrangement may be made without departing from the spirit of the present invention.

100 motor drive device, 200 motor, 110 voltage detector, 112 voltage sensor, 114 first coordinate converter, 120 current detector, 122 current sensor, 124 second coordinate converter, 130 Voltage phase correction unit, 140 estimator, 142 predicted current calculation unit, 144 phase angle estimation unit, 160 motor controller, 180 power unit, 190 current phase correction unit.

Claims (6)

A motor driving device,
A voltage detector that monitors a voltage applied to the motor and generates a detection voltage vector at a predetermined sampling cycle Ts;
A current detection unit that monitors a current flowing through the motor and generates a detection current vector corresponding to a detection value of the current vector;
An estimator for estimating the rotational speed of the motor based on the correction voltage vector and the detected current vector;
Ts / 2 time, assuming that the motor is rotated at a rotational speed ^ omega of the estimator has estimated angle corresponding to ^ ω · Ts / 2, rotates the phase of the detection voltage vector, the correction voltage vector A voltage phase correction unit that generates
A motor controller that generates a control signal so that the estimated value ＾ ω of the rotation speed of the motor approaches the target rotation speed of the motor,
A power unit that drives the motor based on the control signal;
A drive device comprising: The estimator is
Generating a predicted current vector that is the current vector calculated based on the corrected voltage vector , the detected current vector , the rotation speed {ω, and the estimated value e of the induced voltage ;
The drive device according to claim 1 , wherein a phase angle ＾ θ of the rotor is estimated based on a difference between the predicted current vector and the detected current vector. The voltage detector,
a voltage sensor for generating a uvw-phase detection voltage;
a first coordinate converter that converts the detected voltage in a uvw coordinate system into the voltage vector in a γδ coordinate system;
Drive device according to claim 1 or 2, characterized in that it comprises a. Assuming that the motor rotates at the rotation speed ＾ ω estimated by the estimator for a time of Ts / 2, the detection current vector is rotated by an angle corresponding to ＾ ω · Ts / 2 to generate a correction current vector. Further comprising a current phase correction unit,
The estimator, the correction voltage vector and based on the corrected current vector, driving device according to any one of claims 1 to 3, characterized in that for estimating the rotation speed of the motor. The current detector,
a current sensor for generating a uvw-phase detection current;
a second coordinate converter that converts the detected current in a uvw coordinate system into the current vector in a γδ coordinate system;
The driving device according to any one of claims 1 to 4 , comprising: A permanent magnet motor,
The drive device according to any one of claims 1 to 5 , which drives the permanent magnet motor;
An industrial machine comprising:

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