JP2003009599A - Controller fo synchronous motor and elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller of an embedded-magnet synchronous motor and a controller for an elevator, capable of obtaining good output by determining a d-axis current command id * and a q-axis current command iq * under the maximum torque control using a simple method. SOLUTION: In this controller of an embedded-magnet synchronous motor where a permanent is embedded in the rotor thereof, under the maximum torque control for generating the maximum torque of the embedded-magnet synchronous motor at the minimum current, there are provided a current command comput means 10 of computing a d-axis current command id * which performs Maclaurin's expansion of a q-axis current command iq * and is obtained by a relational expression approximated and simplified by a secondary expression of a q-axis current command iq * and the q-axis current command iq * from the obtained d-axis current command id * and a torque command T*, and converting and controlling parts 6, 8, 11, 12, 13, 14 which respectively determine the d-axis current command id *, the q-axis current command iq *, the d-axis and q-axis voltage commands vd *, vq * from the d-axis and q-axis currents determined from the detected values and control the synchronous motor therewith.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an embedded magnet type synchronous motor control device having a structure in which a permanent magnet is embedded inside a rotor, and the embedded device connected to a hoisting machine using the same. The present invention relates to an elevator control device that controls an elevator by driving a magnetic synchronous motor with an inverter.

[0002]

2. Description of the Related Art An embedded magnet type synchronous motor (Interior Perman
ent Magnet Motor) has a structure in which a permanent magnet is embedded inside the rotor, and it can be manufactured smaller than an induction motor with the same output and can operate with high efficiency. May be used for. The embedded magnet type synchronous motor is driven by an AC power source of variable voltage and variable frequency supplied from an inverter.

The embedded magnet type synchronous motor has a property called reverse salient polarity in which the q-axis self-inductance L _q is larger than the d-axis self-inductance L _d in the dq coordinate expression. An electric motor having a reverse saliency can increase the torque by passing a current in the negative direction of the d-axis.
Wide-range variable speed operation using weakening magnetic flux control of M motor
(The Institute of Electrical Engineers of Japan, Volume D, Vol. 114, No. 9, 1994) proposes maximum torque control in which maximum torque is obtained with minimum current.

In the above paper, in the maximum torque control, the d-axis current command i is calculated by the relational expressions shown in the equations (1) and (2).
Determine _d * and q-axis current command i _q *.

I _d * = K ₁ −√ (K ₁ ² + i _q * ² ) (1)

T * = P _n · {φ _a + (L _d −L _q ) · _id *} · i _q * (2) where T * is the torque command P _{n and the number} of pole pairs φ _a √3 × (effective value of armature flux linkage number by permanent magnet) K ₁ = φ _a / {2 · (L _q −L _d )}.

[0007]

However, the above equation
If the d-axis current command i _d * and the q-axis current command i _q * are calculated directly from (1) and equation (2), it takes a long time to calculate, so that the control loop cannot be calculated at high speed, and the responsiveness is deteriorated. There was a conventional problem of getting worse.

The present invention has been made in order to solve the above problems, and does not require an exact solution or an iterative calculation by directly solving the above equations (1) and (2). , By obtaining the d-axis current command i _d * and the q-axis current command i _q * for maximum torque control by a simple method,
An object of the present invention is to provide a control device for an embedded magnet type synchronous motor and an elevator control device that can obtain good output.

[0009]

In view of the above object, the present invention relates to an embedded magnet type synchronous motor control device having a structure in which a permanent magnet is embedded in a rotor. In the maximum torque control for generating the maximum torque with the minimum current in the synchronous motor, the q-axis current command i _q * is obtained by a simplified relational expression which is approximated by a quadratic formula of the q-axis current command i _q *. D-axis current command i _d *, obtained d-axis current command i _d * and torque command T
A current command calculating means for calculating the q-axis current command i _q * from *, and the d-axis current command i _d * and the q-axis current command i _q.
And a conversion / control unit for controlling the synchronous motor based on the d and q axis voltage commands v _d * and v _q * obtained from the d and q axis currents obtained from the detected values. It is in the control device of the characteristic synchronous motor.

In the current command calculation means, the d-axis current command i _d * is the q-axis current command i _q one sample before.
Using * [z ^-1 ], the following equation, i _d * =-i _q * [z ^-1 ] ² / (2 · K ₁ ) where K ₁ = φ _a / {2 · (L _q −L _d ). } φ _a is √3 × (effective value of the number of armature flux linkages by permanent magnets) L _d is the d-axis self-inductance L _q is determined according to the q-axis self-inductance is there.

Further, the current command calculation means includes a memory for storing the q-axis current command i _q * [z ^-1 ] one sample before,
From the q-axis current command i _q * [z ^-1 ] one sample before, the following expression, i _d * =-i _q * [z ^-1 ] ² / (2 · K ₁ ), where K ₁ = φ _a / { 2 · (L _q −L _d )} φ _a is √3 × (effective value of the number of armature flux linkages by permanent magnets) L _d is the d-axis self-inductance L _q is the d-axis current command according to the q-axis self-inductance From the d-axis current command calculation unit that calculates i _d *, and the calculated d-axis current command i _d * and torque command T *, the following equation, i _q * = T * / [P _n · {φ _a + ( L _d −L _q ) · _id *}] where P _n includes a q-axis current command calculation unit that calculates a q-axis current command i _q * according to the _number of pole pairs, and is a controller for a synchronous motor. It is in.

Further, by controlling the drive of the embedded magnet type synchronous motor by the control device of the synchronous motor, the hoisting machine connected thereto is rotationally driven to drive the elevator. It is in.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in accordance with embodiments. Embodiment 1. FIG. 1 shows the configuration of an elevator control apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a car, 2 is a counterweight, 3 is a rope, 4 is an embedded magnet type synchronous motor (IPM), 5 is a hoisting machine, 6 is an inverter,
7 is a rotation detector, 8 is a speed / position signal processor, 9 is a speed controller, 10 is a current command calculator, 11 is an A / D converter,
Reference numeral 12 is a coordinate converter, 13 is a current controller, 14 is a coordinate converter, and 15 is a current detection device.

First, the general operation of the elevator will be described. A car 1 and a counterweight 2 are connected to each other via a rope 3, and a hoisting machine 5 connected thereto by an embedded magnet type synchronous motor 4. Is driven to drive the elevator, that is, the car 1 is moved up and down. The embedded magnet type synchronous motor 4 is driven by the variable voltage / variable frequency AC power supplied from the inverter 6.

Next, the control operation of the embedded magnet type synchronous motor 4 will be described. A rotation detector 7 including an encoder detects the rotation of the embedded magnet type synchronous motor 4. speed·
The position signal processor 8 calculates the speed and position of the synchronous motor 4 as the angular velocity ω and the angle θ based on the signal from the rotation detector 7. The speed controller 9 calculates the torque command T * from the deviation between the speed command ω * from the outside and the angular speed ω. Then, the current command calculation unit 10 calculates the d, q-axis current commands i _d *, i _q * from the torque command T * as described in detail later.

The current detection device 15 measures the three-phase alternating current output from the inverter 6, and the output of the current detection device 15 is converted into a digital signal by the A / D converter 11 and input to the coordinate converter 12. . The coordinate converter 12 converts the measured values of the three-phase alternating current converted into digital signals into d and q axis currents i _d and i _q . The current controller 13, d from the current command calculating unit 10, q-axis current command i _d *, i _q * and d from coordinate converter 12, q-axis current i _d, the i _q, d, q
The voltage commands v _d *, v _q * are obtained. And the coordinate converter 14
Is output from the current controller 13 d, q voltage command v
_d *, _vq * is converted into a three-phase AC voltage command, which is supplied to the inverter 6, and the drive control of the embedded magnet type synchronous motor 4 is performed by the inverter 6.

In the following, the d-axis current command i _d * and the q-axis of the maximum torque control are obtained without directly obtaining the exact solution by directly solving the above equations (1) and (2) or performing repeated calculations. Current command calculator 1 that calculates current command i _q * by a simple method
The calculation process at 0 will be described in detail.

When the Maclaurin expansion is performed on the relational expression of the above equation (1) and the approximation is performed by the quadratic equation of i _q *, the equation (3) is obtained.

I _d * = − (i _q *) ² / (2 · K ₁ ) ... (3)

When the d-axis current command i _d * is fixed in the above equation (2), the torque command T * and the q-axis current command i _q * are in a proportional relationship, and q can be easily calculated from the given torque command T *. The axis current command i _q * can be obtained. So 1
Using previous sample q-axis current command i _q * [z ^-1] to calculate the d-axis current command i _d * above, obtaining the q-axis current command i _q * from the torque command T *. At this time, the d-axis current command _id * is calculated by the equation (4).

I _d * = − i _q * [z ⁻¹ ] ² / (2 · K ₁ ) ... (4) where K ₁ = φ _a / {2 · (L _q −L _d )} φ _a Is √3 × (effective value of the number of armature flux linkages by the permanent magnet) L _d is the d-axis self-inductance L _q is the q-axis self-inductance

By solving the equation 2 for i _q *, the equation (5) is obtained.

I _q * = T * / [P _n · {φ _a + (L _d −L _q ) · i _d *}] (5) where T * is the torque command P _n is the number of pole pairs

From equations (4) and (5), the d and q axis current commands i _d
By obtaining *, i _q *, it is possible to obtain a current command that is substantially equal to the current command obtained by the maximum torque control algorithm by a simple method.

According to the present invention having such a configuration, the d, q-axis current commands i _d *,
Find i _q *. FIG. 2 is a block diagram showing an example of the configuration of the current command calculation unit 10 of FIG.

The d-axis current command i _d * is calculated from the q-axis current command i _q * [z ^-1 ] one sample before stored in the memory 10a or the like by the d-axis current command calculation unit 10b according to the above equation (4). Calculated. The q-axis current command i _q * is calculated from the d-axis current command i _d * and the torque command T * by the q-axis current command calculation unit 10c.
Is calculated according to the above equation (5).

[0027]

As described above, according to the present invention, there is provided an embedded magnet type synchronous motor control device having a structure in which a permanent magnet is embedded in a rotor, wherein the embedded magnet type synchronous motor is used. in the maximum torque control for generating a maximum torque at minimum current, q-axis current command i _q * for performs Maclaurin expansion q-axis current command i _q * of d-axis current obtained by the approximate simplified equation by a quadratic equation A current command calculation means for calculating the command i _d *, the obtained d-axis current command i _d *, and the q-axis current command i _q * from the torque command T *, and the d-axis current commands i _d * and q. Based on the axis current command i _q * and the d and q axis currents obtained from the detected values, the d and q axis voltage commands v _d
Since the control device of the synchronous motor is characterized by including * and v _q * respectively, and a conversion / control unit for controlling the synchronous motor based on these, d that generates maximum torque with minimum current. , Q-axis current command can be easily obtained without using an arithmetic unit capable of high-speed processing, and thus the arithmetic cycle of the control loop can be shortened even if an arithmetic unit with low-speed processing is used. A highly stable control characteristic can be obtained.

In the current command calculation means, the d-axis current command i _d * is the q-axis current command i _q one sample before.
Using * [z ^-1 ], the following equation, i _d * =-i _q * [z ^-1 ] ² / (2 · K ₁ ) where K ₁ = φ _a / {2 · (L _q −L _d ). } φ _a is √3 × (effective value of the number of armature flux linkages by permanent magnets) L _d is the d-axis self-inductance L _q is determined according to the q-axis self-inductance. Therefore, the maximum torque control algorithm is used. A current command almost equal to the required current command can be obtained by a simple method.

Further, the current command computing means stores a memory for storing a q-axis current command i _q * [z ^-1 ] one sample before,
From the q-axis current command i _q * [z ^-1 ] one sample before, the following expression, i _d * =-i _q * [z ^-1 ] ² / (2 · K ₁ ), where K ₁ = φ _a / { 2 · (L _q −L _d )} φ _a is √3 × (effective value of the number of armature flux linkages by permanent magnets) L _d is the d-axis self-inductance L _q is the d-axis current command according to the q-axis self-inductance From the d-axis current command calculation unit that calculates i _d *, and the calculated d-axis current command i _d * and torque command T *, the following equation, i _q * = T * / [P _n · {φ _a + ( L _d −L _q ) · _id *}] where P _n includes a q-axis current command calculation unit that calculates the q-axis current command i _q * in accordance with the _number of pole pairs. Can be implemented with a simple configuration.

Further, since the control device for the synchronous motor drives and controls the embedded magnet type synchronous motor, the hoisting machine connected thereto is rotationally driven to drive the elevator. It is possible to easily obtain the d and q axis current commands that generate the maximum torque by the current without using an arithmetic unit capable of high-speed processing. As a result, even if an arithmetic unit with a low processing speed is used, a control loop can be obtained. The calculation cycle of can be shortened, and an elevator control device with high stability can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an elevator control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a configuration of a current command calculation unit in FIG.

[Explanation of code] 1 car, 2 counterweight, 3 rope, 4
Embedded magnet type synchronous motor, 5 hoisting machine, 6 inverter, 7 rotation detector, 8 speed / position signal processor, 9 speed controller, 10 current command calculator, 10a memory, 1
0b d-axis current command calculation unit, 10c q-axis current command calculation unit, 11 A / D converter, 12 coordinate converter, 13 current controller, 14 coordinate converter, 15 current detection device.

Continued front page    F term (reference) 5H560 AA10 BB04 BB12 DB07 DC12                       EB01 GG04 RR06 TT11 TT15                       XA02 XA13                 5H576 AA07 BB09 DD05 EE01 GG02                       GG04 HB01 JJ02 JJ08 LL01                       LL22 LL45

Claims (4)

[Claims] 1. A controller for an embedded magnet type synchronous motor having a structure in which a permanent magnet is embedded in a rotor, wherein maximum torque is generated in the embedded magnet type synchronous motor with a minimum current. In the control, the q-axis current command i _q * is subjected to the Maclaurin expansion and the q-axis current command i _q * 2
A d-axis current command _id * obtained by a simplified relational expression approximated by the following equation and a q-axis current command _iq * are calculated from the obtained d-axis current command _id * and torque command T *. Current command calculation means, the d-axis current command i _d * and the q-axis current command i _q *, and the d and q-axis voltage commands v _d * and v _q * from the d and q-axis currents obtained from the detected values. A control device for a synchronous motor, comprising: a conversion / control section that controls the synchronous motor based on the respective requirements. 2. The current command calculation means, wherein d
The axis current command i _d * is the q-axis current command i _q * one sample before
Using [z ^-1 ], the following equation, i _d * =-i _q * [z ^-1 ] ² / (2 · K ₁ ) where K ₁ = φ _a / {2 · (L _q −L _d )} 2. The synchronization according to claim 1, wherein φ _a is √3 × (effective value of the number of magnetic flux linkages of the armature by permanent magnets) L _d is d-axis self-inductance L _q is determined according to q-axis self-inductance Electric motor controller. 3. The current command calculation means stores a memory for storing a q-axis current command i _q * [z ^-1 ] one sample before, and a q-axis current command i _q * [z ^{-1 for} one sample before. ] From the following equation, i _d * =-i _q * [z ^-1 ] ² / (2 · K ₁ ) where K ₁ = φ _a / {2 · (L _q −L _d )} φ _a is √3 × (Effective value of the number of armature flux linkages by permanent magnets) L _d is the d-axis self-inductance L _q is the d-axis current command i _d * according to the q-axis self-inductance d-axis current command i _d * and the following equation from the torque command _{T *, i q * = T} * / [P n · {φ a + (L d -L q) · i d *}] However, P _n The control device for the synchronous motor according to claim 1, further comprising: a q-axis current command calculation unit that calculates a q-axis current command i _q * according to the number of pole pairs. 4. An elevator is driven by rotationally driving a hoisting machine connected to an embedded magnet type synchronous motor by drivingly controlling the embedded magnet type synchronous motor by the synchronous motor control device according to any one of claims 1 to 3. An elevator control device characterized by being driven.