JP2006050766A - Induction motor drive device and tuning method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device with which a double-winding induction motor can be tuned. <P>SOLUTION: A second inverter is gate-blocked, and first winding is excited with direct-current voltage to identify the primary resistance of the first winding. A first inverter is gate-blocked, and second winding is excited with direct-current voltage to identify the primary resistance of the second winding. Thereafter, no-load operation is performed at a predetermined rotation speed, no-load current is measured and the primary leakage inductance and the excitation inductance of an induction motor are identified. The induction motor is locked, and voltage of a predetermined frequency is applied to measure current. Then, the primary leakage inductance and the secondary leakage inductance are identified. The induction motor is excited at a predetermined frequency and is rotated under no load. Then, current is measured with voltage amplitude variable. In a state in which no-load operation is performed at a predetermined rotation speed, a current command is zeroed to observe the amount of attenuation in voltage command. A secondary time constant is determined, and these constants are set as control parameters on the drive device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an induction motor drive device for controlling a large capacity induction motor having double windings by two sets of inverters and a tuning method thereof.

For example, Patent Literature 1 discloses a conventional tuning method for a drive device. The prior art will be described with reference to the drawings.
FIG. 5 is an example of the prior art. In FIG. 5, 101 is a three-phase power source, 102 is a converter, 103 is a smoothing capacitor, 104 is an inverter, 105 is an induction motor, 106 is a speed command circuit, 107 is a vector control arithmetic circuit, and 108 is a pulse width modulation (PWM) circuit. It is. Reference numeral 111 denotes a speed detector, 112 denotes a current detector, 120 denotes basic data setting means, and 121 denotes auto-tuning means.

Next, the operation will be described. The basic data setting means 120 sets the rated frequency fB, the rated rotation speed SB, the rated current Im, the number of poles Pm, and the base voltage VB as basic data for measuring the circuit constants of the induction motor 105. The auto-tuning means 121 obtains the motor excitation current Ids from the no-load current I0 at the rated rotation detected by the current detector 112, and the rated frequency fB of the induction motor 105 set by the basic data setting means 120 and the rating The rated slip angular frequency ωsr is obtained from the rotational speed SB, the secondary inductance L2 is obtained from the base voltage VB of the induction motor 105 set by the basic data setting means 120, the rated frequency fB and the no-load current I0, and the basic data setting means 120 is obtained. The rated torque current Iqr is obtained from the rated current Im of the induction motor 5 and the motor excitation current Ids set by the following equation. The next resistor R2 is set for calculation.

As basic data for measuring the circuit constants of the induction motor 105, the rated frequency fB, the rated rotational speed SB, the rated current Im, the number of poles Pm, and the base voltage VB are set for the auto tuning means by the basic data setting means 120. . The auto tuning unit 121 receives the basic data of the induction motor 105 set by the basic data setting unit 120, and accelerates the induction motor 105 to the base frequency fB with a V / F pattern determined by the rated frequency fB and the base voltage VB. At this time, if the no-load current flowing through the induction motor 5 is I0, the torque component current I1q becomes zero, so the following equation is established.
VB = 2π · fB · L1 · I0 (1)
(However, L1 = l1 + M)
I0 = Ids / √3 (2)
Here, the no-load current I0 is a value detected by the current detector 112. When the expression (2) is expanded with respect to the motor excitation current Ids, the following expression (3) is obtained.
Ids = I0 · √3 (3)
The auto-tuning means 121 takes in the no-load current I0 from the current detector 112, obtains the motor excitation current Ids by the equation (3), and sets it in the vector control arithmetic circuit 7. As a result, the motor excitation current Ids is set with high accuracy, and magnetic flux control with high accuracy is performed.
However, the prior art is not related to the double winding of the induction motor, and cannot be applied to the double winding induction motor as it is.
JP-A-10-243698

  The present invention has been made in view of such problems, and an object thereof is to identify a constant of a double-winding induction motor and set the identified constant as a control parameter in the induction motor drive device.

The present invention according to claim 1 is a drive device for driving an induction motor having a double winding of a first winding and a second winding on a stator, the first inverter driving a first winding, and the In a tuning method of a drive device constituted by a second inverter that drives a second winding, the second inverter is gate-blocked, and the first winding is DC voltage excited by the first inverter and 1 of the first winding. A step of identifying a secondary resistance, a step of gate-blocking the first inverter, a step of identifying a primary resistance of the second winding by performing DC voltage excitation on the second winding with the second inverter, (2) operating the inverter, performing no-load operation at a predetermined rotational speed, measuring the no-load current, and identifying the primary leakage inductance and the excitation inductance of the first winding and the second winding; Lock the motor Applying a voltage of a predetermined frequency from the first inverter and the second inverter, measuring a current, and identifying a primary leakage inductance and a secondary leakage inductance of the first winding and the second winding; The current command is set to zero in the state where the first inverter is operating at no load at a predetermined rotational speed, the attenuation amount of the voltage command is measured, and the secondary time constants of the first winding and the second winding are obtained. The step and the constant of the induction motor determined in each step are set as the control parameters of the drive device.

According to a second aspect of the present invention, in the tuning method for an induction motor drive device according to the first aspect, the first and second inverters are operated to excite the induction motor at a predetermined frequency, and the induction motor is rotated without load. The voltage amplitude is made variable, the current is measured, and a step for obtaining magnetic saturation is provided.

According to a third aspect of the present invention, there is provided a drive device for driving an induction motor having a double winding of a first winding and a second winding on a stator, the first inverter driving a first winding, and the In a drive device composed of a second inverter for driving the second winding, a vector control calculation means for inputting a speed command and the speed of the induction motor and calculating a d / q axis current command from parameters of the induction motor; a first current control means for generating a first d / q-axis voltage command by performing control processing on the d / q-axis current command and the d / q-axis current of the first winding; Second current control means for generating a second d / q-axis voltage command by performing control processing on the d / q-axis current of the winding, and converting the first d / q-axis voltage command into a first U / V / W voltage command The first coordinate conversion means and the second d / q axis voltage command are converted into a second U / V / W voltage command. Second coordinate conversion means; first PWM generation means for converting the first U / V / W voltage command into a first PWM signal; second PWM generation means for converting the second U / V / W voltage command into a second PWM signal; A first current detecting means for detecting a first U / V / W-phase current from one winding; a second current detecting means for detecting a second U / V / W-phase current from a second winding; Identification of third coordinate conversion means for converting W-phase current into first d · q-axis current, fourth coordinate conversion means for converting second U · V · W-phase current into second d · q-axis current, and induction motor identification And a basic data setting means for setting constants in the tuning means. The tuning means gate-blocks the second inverter, and the first inverter excites the first winding with a DC voltage to 1 of the first winding. The secondary resistance is identified and the first inverter is gate-blocked The second winding is DC voltage excited to identify the primary resistance of the second winding, the first inverter and the second inverter are operated, and no load operation is performed at a predetermined rotational speed. Then, the no-load current is measured, the primary leakage inductance and the excitation inductance of the first winding and the second winding are identified, the induction motor is locked, and the voltage of the predetermined frequency is obtained from the first inverter and the second inverter. Apply and measure the current, identify the primary leakage inductance and secondary leakage inductance of the first winding and the second winding, and perform no-load operation at a predetermined rotational speed with the second inverter and the first inverter. The current command is set to zero while the current command is zero, the attenuation of the voltage command is measured, the secondary time constant of the first winding and the second winding is obtained, and the obtained induction motor constant is set as the control parameter of the drive device With something to do That.

According to a fourth aspect of the present invention, in the induction motor drive device according to the third aspect, the first and second inverters are operated to excite the induction motor at a predetermined frequency, the induction motor is rotated without load, and the voltage is increased. The current is measured with variable amplitude, and magnetic saturation is obtained.

  According to the present invention, it is possible to identify a constant of a double-winding induction motor and set the identified constant as a control parameter in the induction motor drive device.

Specific examples of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a drive device that realizes a method for tuning an induction motor according to the present invention. In FIG. 1, 1 is a three-phase power supply device, 2 is a converter that converts a three-phase AC voltage into a DC voltage, 3 is a DC voltage smoothing electrolytic capacitor, 4 and 5 are a first inverter, a second inverter, and 6 are doubles, respectively. Induction motor having three-phase windings, 7 is a first winding of the induction motor, 8 is a second winding of the induction motor, 9 is position detection means, 10 and 11 are first current detection means and second current, respectively. It is a detection means. 12 is a vector control calculation means, 13 and 14 are first current control means and second current control means, 15 is first coordinate conversion means, 16 is second coordinate conversion means, 17 is position trigonometric function conversion means, 18 Is a position / speed conversion means, 19 is a third coordinate conversion means, 20 is a fourth coordinate conversion means, 21 is a first PWM conversion means, 22 is a second PWM conversion means, 23 is an auto-tuning means, and 24 is a basic data setting means. .

Next, the operation will be described. The vector control calculation means 12 uses the primary resistance R1, the secondary resistance R2, the primary inductance L1, the secondary inductance L2, and the excitation current Ids that are parameters of the induction motor from the speed command ω * and the speed ω of the induction motor. The d-axis current command Id * and the q-axis current command Iq * are generated by calculation. The first current control means 13 performs control arithmetic processing on the d-axis current command Id *, the q-axis current command Iq *, the first d-axis current Id1 and the first q-axis current Iq1 of the first winding, and the first d-axis voltage command Vd1 * and a first q-axis voltage command Vq1 * are generated. The second current control means 14 performs control arithmetic processing on the d-axis current command Id *, the q-axis current command Iq *, the second d-axis current Id2 and the second q-axis current Iq2 of the second winding, and performs a second d-axis voltage command. Vd2 * and a second q-axis voltage command Vq2 * are generated. The first PWM conversion means converts the first d · q-axis voltage commands Vd1 *, Vq1 * into first PWM signals PU1 *, * PU1 *, PV1 *, * PV1 *, PW1 *, * PW1 *. The first PWM signals PU1 *, * PU1 *, PV1 *, * PV1 *, PW1 *, * PW1 * are insulated and amplified by a first gate drive means (not shown) to drive the gate of the first inverter 4. When the gate is driven, the first inverter applies a PWM voltage to the first winding of the induction motor, and first winding currents Iu1, Iv1, and Iw1 flow. The second PWM conversion means converts the second d · q-axis voltage commands Vd2 *, Vq2 * into first PWM signals PU2 *, * PU2 *, PV2 *, * PV2 *, PW2 *, * PW2 *. The second PWM signals PU2 *, * PU2 *, PV2 *, * PV2 *, PW2 *, * PW2 * are insulated and amplified by a second gate drive means (not shown) to drive the gate of the second inverter 5. When the gate is driven, the second inverter applies PWM voltage to the second winding of the induction motor, and second winding currents Iu2, Iv2, and Iw2 flow. When the first winding current and the second winding current flow, the induction motor generates torque and rotates according to the moment of inertia and the load. The first current detection means 10 detects the first winding current and outputs Iu1, Iv1, Iw1 to the third coordinate conversion means. The third coordinate conversion unit 19 performs coordinate conversion of Iu1, Iv1, and Iw1 with a trigonometric function of position to generate first d · q axis currents Id1 and Iq1, and outputs them to the first current control unit and the tuning unit. The second current detection means 11 detects the second winding current and outputs Iu2, Iv2, Iw2 to the fourth coordinate conversion means. The fourth coordinate conversion means 20 performs coordinate conversion of Iu1, Iv1, and Iw1 with position trigonometric functions to generate d · q-axis currents Id2 and Iq2, and outputs them to the second current control means and the auto-tuning means. The position detecting means detects the rotational position θ of the induction motor and outputs the position θ to the position trigonometric function converting means 17 and the position speed converting means 18. The position trigonometric function converting means 17 calculates the drive electrical angle θe of the induction motor from the position θ of the induction motor and the d · q axis current commands Id * and Iq *, and obtains a trigonometric function sin (θe) · cos (θe) as a first function. Output to the second, third, fourth and coordinate converters.

The constant of the induction motor will be described with respect to the tuning means. When the tuning mode is set, first, the basic data setting unit 24 sets the rated rotational speed, the number of poles, and the like in the tuning unit. Next, the tuning means generates a second inverter gate block signal to gate block the second inverter, and the first inverter excites the first winding with a DC voltage. The primary resistance of the first winding is identified from the relationship between the excitation voltage and the flowing current. Next, the second inverter gate block signal is canceled, the first gate block signal is generated to gate block the first inverter, and the second winding is DC voltage excited by the second inverter. The primary resistance of the second winding is identified from the relationship between the excitation voltage and the flowing current.

Next, the first inverter and the second inverter are operated simultaneously to perform no-load operation at a predetermined rotational speed, and the no-load current is measured. The primary leakage inductance and excitation inductance of the induction motor are identified from the measured no-load current. Next, the induction motor is locked, the voltage of a predetermined frequency is applied from the first inverter and the second inverter, the current is measured, and the primary leakage inductance and the secondary leakage inductance of the first winding and the second winding are identified. To do. Next, with the second inverter and the first inverter operating at no load at a predetermined rotational speed, the current command is set to zero, the attenuation amount of the voltage command is observed, and the first and second windings are observed. Obtain the second-order time constant. Furthermore, the constant of the identified induction motor is set as a control parameter for the induction motor drive device, and the tuning is completed.
When tuning is complete, a tuning completion display signal is generated to prepare for exiting tuning mode.

FIG. 2 is a flowchart showing the tuning method of the present invention.
In FIG. 2, steps ST1 to ST3 are steps for identifying the primary resistance of the first winding of the induction motor. In step ST1, the gate of the second inverter is blocked, and in step ST2, the first winding is DC-excited by the first inverter. In step ST3, the primary resistance is identified from the relationship between the voltage and current of the first winding.
Steps ST4 to ST6 are steps for identifying the primary resistance of the second winding of the induction motor. In step ST4, the gate of the first inverter is blocked, and in step ST5, the second inverter is DC-excited by the second inverter. In step ST6, the primary resistance is identified from the relationship between the voltage and current of the second winding.
Steps ST7 to ST9 are steps for identifying the primary leakage inductance and the excitation inductance of the first winding and the second winding. In step ST7, the first inverter is excited with the first inverter, the second inverter is excited with the second winding at a predetermined frequency, and no-load operation is performed. In step ST8, the no-load current is measured. In step ST9, the primary leakage inductance and the excitation inductance of the first winding and the second winding are identified.
Steps ST10 to ST12 are steps for identifying the primary leakage inductance and the secondary leakage inductance of the first winding and the second winding. In step ST10, the rotor of the induction motor is locked. In step ST11, the first inverter excites the first winding and the second inverter excites the second winding at a predetermined frequency. In step ST12, the primary leakage inductance and the secondary leakage inductance of the first winding and the second winding are identified.
Steps ST13 and ST14 are steps for identifying a secondary time constant. In step ST13, no-load operation is performed at a predetermined rotational speed, and the current command is set to zero. In step ST14, the voltage command after the current command is set to zero is observed, and the secondary time constants of the first winding and the second winding are identified from the attenuation.
Step 15 tunes the control parameters of the induction motor controller based on the identified induction motor constants.
In this way, R11, R12, L11, L12 of the first winding, R21, R22 of the second winding are identified and set as control parameters of the induction motor control device.
FIG. 3 shows an embodiment in which the magnetic saturation characteristic of the induction motor is added to a constant, and includes step 16 and step 17. In step 16, the induction motor is operated with no load to change the excitation voltage from 50% to 100% of the rated excitation voltage. In step 17, magnetic saturation is identified by looking at the relationship between the excitation voltage and the excitation current. This is because, during normal operation, an excitation current command is given to generate a secondary magnetic flux, and therefore accurate secondary magnetic flux control cannot be performed unless magnetic saturation is taken into consideration. FIG. 4 shows the relationship between the excitation current and the secondary magnetic flux. The coordinates of the polygonal line of the excitation voltage and the excitation current are stored in the induction motor drive device and used for controlling the secondary magnetic flux.

In order to drive an induction motor having a capacity far exceeding the capacity of an economical general-purpose semiconductor switching element, a combination of a multi-winding motor and a plurality of inverters is indispensable. In particular, application can be expected to increase the size of electric injection molding machines and electric press machines.

Block diagram of the drive device of the present invention Flowchart illustrating the method of the present invention Flowchart illustrating the method of the present invention The figure which shows the magnetic saturation characteristic of the induction motor Block diagram showing conventional auto tuning

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 3 phase power supply device 2 Converter 3 Electrolytic capacitor 4 1st inverter 5 2nd inverter 6 Double winding induction motor 7 First winding 8 Second winding 9 Position detection means 10 First current detection means 11 Second current detection Means 12 Vector control calculation means 13 First current control means 14 Second current control means 15 First coordinate conversion means 16 Second coordinate conversion means 17 Position trigonometric function conversion means 18 Position velocity conversion means 19 Third coordinate conversion means 20 Fourth Coordinate conversion means 21 First PWM conversion means 22 Second PWM conversion means 23 Tuning means 24 Basic data setting means

Claims (4)

A drive device for driving an induction motor having a double winding of a first winding and a second winding on a stator, wherein a first inverter that drives the first winding and a second drive that drives the second winding In a tuning method of a drive device composed of two inverters,
Gate-blocking the second inverter and direct voltage excitation of the first winding with the first inverter to identify a primary resistance of the first winding;
Identifying the primary resistance of the second winding by gate-blocking the first inverter and exciting the second winding with a DC voltage with the second inverter;
The first inverter and the second inverter are operated, the no-load operation is performed at a predetermined rotational speed, the no-load current is measured, the primary leakage inductance of the first winding and the second winding, Identifying the excitation inductance;
The induction motor is locked, a voltage of a predetermined frequency is applied from the first inverter and the second inverter, current is measured, and primary leakage inductance and secondary leakage of the first winding and the second winding are measured. Identifying the inductance; and
The current command is set to zero in a state in which no load operation is performed at a predetermined rotational speed by the second inverter and the first inverter, the attenuation amount of the voltage command is measured, and the first winding and the second winding are measured. Obtaining a second order time constant of
A method of tuning an induction motor drive device, wherein the constant of the induction motor obtained in each step is set as a control parameter of the drive device. Activating the first inverter and the second inverter to excite the induction motor at a predetermined frequency, rotating the induction motor without load, measuring the current with variable voltage amplitude, and obtaining magnetic saturation. The method of tuning an induction motor drive device according to claim 1, wherein: A drive device for driving an induction motor having a double winding of a first winding and a second winding on a stator, wherein a first inverter that drives the first winding and a second drive that drives the second winding In a drive device composed of two inverters,
A vector control calculation means for inputting a speed command and the speed of the induction motor and calculating a d / q-axis current command from the parameters of the induction motor;
A first current control means for generating a first d / q-axis voltage command by performing a control process on the d / q-axis current command and the d / q-axis current of the first winding;
A second current control means for generating a second d / q-axis voltage command by performing a control process on the d / q-axis current command and the d / q-axis current of the second winding;
First coordinate conversion means for converting the first d / q-axis voltage command into a first U / V / W voltage command;
Second coordinate conversion means for converting the second d / q-axis voltage command into a second U / V / W voltage command;
First PWM generating means for converting the first U / V / W voltage command into a first PWM signal;
Second PWM generating means for converting the second U, V, W voltage command into a second PWM signal;
First current detection means for detecting a first U / V / W phase current from the first winding;
Second current detection means for detecting a second U / V / W phase current from the second winding;
Third coordinate conversion means for converting the first U / V / W-phase current into first d / q-axis current;
A fourth coordinate conversion means for converting the second U / V / W phase current into a second d / q axis current;
A basic data setting means for setting a constant for identifying the induction motor in the tuning means,
The tuning means includes
The second inverter is gate-blocked, the first inverter is DC voltage excited with the first inverter to identify the primary resistance of the first winding,
The first inverter is gate-blocked, and the second inverter is DC voltage excited with the second inverter to identify the primary resistance of the second winding,
The first inverter and the second inverter are operated, the no-load operation is performed at a predetermined rotational speed, the no-load current is measured, the primary leakage inductance of the first winding and the second winding, Identify the excitation inductance,
The induction motor is locked, a voltage of a predetermined frequency is applied from the first inverter and the second inverter, current is measured, and primary leakage inductance and secondary leakage of the first winding and the second winding are measured. Identify the inductance,
The current command is set to zero in a state in which no load operation is performed at a predetermined rotational speed by the second inverter and the first inverter, the attenuation amount of the voltage command is measured, and the first winding and the second winding are measured. Find the second-order time constant of the line
An induction motor drive device, wherein the obtained constant of the induction motor is set as a control parameter of the drive device. Operating the first inverter and the second inverter to excite the induction motor at a predetermined frequency, rotating the induction motor with no load, measuring a current with a variable voltage amplitude, and obtaining magnetic saturation. The induction motor drive device according to claim 3.

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