JPH0463634B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Technical Field>> The present invention relates to a current command generator for a device for driving and controlling a permanent magnet type synchronous motor.

≪Prior art and its problems≫ Japanese Unexamined Patent Publication No. 1823/1983 is known.

In a device that drives and controls a permanent magnet type synchronous motor, the motor drive current is controlled according to a current command obtained from a current command generator.

However, since the current command was determined based on the assumption that the torque was simply proportional to the load angle and current amplitude, the torque command and the torque generated by the motor did not exactly match, and it was difficult to improve the torque response. Therefore, there was a problem in trying to improve the control response and efficiency of the motor.

<<Object of the Invention>> The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a current command generator that can improve control responsiveness and efficiency of a motor. be.

<<Structure of the Invention>> In order to achieve the above object, the present invention provides a torque component current command calculation that calculates a torque component current command i ₁ d according to the formula i ₁ d=T/Φ using a torque command T and a magnetic flux command Φ. Find the load angle command δ using the motor's primary inductance L, motor permanent magnet effective magnetic flux φ, torque command T, and magnetic flux command Φ according to the formula δ=sin ^-1 (L/φ・T/Φ). Load angle command calculation means, primary inductance L of the motor, magnetic flux command Φ,
A magnetic flux component current command calculation means for calculating a magnetic flux component current command _i1q using the load angle command δ according to the formula _i1q =(Φ-φcosδ)/L, a torque component current command _i1d , a magnetic flux component current command
i ₁ q _{, the} ^detected rotation ^angle θ _{0 of the} motor rotor ^, and the load angle command δ to determine _the current command i for the motor _. q)} or an approximate expression thereof; and current command calculation means.

<<Embodiments of the Invention>> Hereinafter, preferred embodiments of the apparatus according to the present invention will be described based on the drawings.

In FIG. 1, the DC output current of an on-vehicle battery 10 is converted into three-phase alternating current by a PWM inverter 12, and the alternating current is supplied as a drive current to a permanent magnet disk type synchronous motor 14.

FIG. 2 shows a side cross section of the permanent magnet disk type synchronous motor 14, in which a rotor 18 and a permanent magnet 20 are fixed to the rotating shaft 16.

The rotor 18 is made up of magnetically permeable materials formed in a substantially tray shape that are opposed to each other, and a magnetic circuit 22 is formed by the magnetomotive force of a permanent magnet 20 inserted between the two.

Further, a stator 24 is inserted into a gap formed on the circumferential surface of the rotor 18, and a motor torque is generated by the flow of a current 26, and the rotor 18 is rotated by the reaction.

Further, the rotation of the rotor 18 is detected by a rotation sensor 28, and by monitoring the detection signal, the first
The rotor rotation angle θ ₀ is detected by the rotor position detector 30 in the figure.

In Fig. 1, this device includes a torque command generator 3.
2 and a magnetic flux command generator 34 are provided,
The torque command T and magnetic flux command φ are supplied to a divider 38 of a current command generator 36.

In this divider 38, the torque component current command i ₁ d is determined by the calculation process of equation (1): i ₁ d=T/Φ.

Furthermore, the command i ₁ d is an arithmetic unit (inverse sine function generator)
In the arithmetic unit (inverse sine function generator) 40, the load angle command δ is determined by the primary inductance L of the permanent magnet disk type synchronous motor 14, the permanent magnet effective magnetic flux φ, and this command i ₁ d. =sin ^-1 (L/φ·i ₁ d) = sin ^-1 (L/φ.T/Φ) ... It is determined by the calculation process of equation (2).

The command δ obtained by the arithmetic unit (inverse sine function generator) 40 is obtained by the arithmetic unit (inverse cosine function generator) 42.
is supplied to the arithmetic unit (cosine inverse function generator)
42, the value φcosδ is determined.

The value φcosδ is subtracted from the command Φ in the computing unit 44, and this subtraction value is supplied to the computing unit 46.

The arithmetic unit 46 uses the subtraction value of the arithmetic unit 44 and the primary inductance L of the permanent magnet disc type synchronous motor 14 to calculate the magnetic flux component current command i ₁ q as follows: i ₁ q = (Φ-φcosδ)/L... It is determined by equation (3).

Further, the magnetic flux component current command i ₁ q and the torque component current command i ₁ d are supplied to an arithmetic unit 48 and an arithmetic unit (tangent inverse function generator) 50.

In the calculator 48, the current amplitude command √i ₁ q ² +
i ₁ d ² is calculated, and the arithmetic unit 50 calculates the phase angle
tan ^-1 (i ₁ d/i ₁ q) is required.

In addition, the phase angle tan ^-1 (i ₁ d/i ₁ q) is input to the computing unit 52 along with the load angle command δ and the rotor detection rotation angle θ ₀ .
In this arithmetic unit 52, the phase angle command θ is determined by equation (4): θ=θ ₀ +δ+θ ₁ .

This phase angle command θ is the current amplitude command i ₁
is also supplied to the vector multiplier 54,
In this vector multiplier 54, the current commands iu, iv, and iw of each phase are iu=√ ₁ ² + ₁ ² sin (θ ₀ + δ + θ ₁ )...Equation (5) iv=√ ₁ ² + ₁ ² sin (θ ₀ +δ+θ ₁ +2π/3) ...... Equation (6) iw = √ ₁ ² + ₁ ² sin (θ + δ + θ ₁ + 4π/3) ...... It is determined by Equation (7).

These current commands iu, iv, iw are supplied to the PWM inverter 12, and these current commands iu,
Three-phase alternating currents corresponding to iv and iw are supplied to the permanent magnet disk type synchronous motor 14 as drive currents.

The present embodiment has the above configuration, and its operation will be explained below.

As understood from the description of the permanent magnet disk type synchronous motor 14 in FIG. 2, the permanent magnet disk type synchronous motor 14 has a positional relationship between current and magnetic flux that is opposite to that of a normal motor.

Here, when the two-pole model shown in FIG. 3 is assumed for the permanent magnet disk type synchronous motor 14, the torque is generated as follows.

In FIG. 3, the coordinates (q, d) are taken in the direction of the effective magnetic flux Φ _A , and the magnetic flux φ _A is obtained by the permanent magnet.

At this time, the magnetic flux components in each direction can be expressed by Φ _A = φ _A cos δ + Li ₁ q . . . Equation (8) O = φ sin δ + Li ₁ d . . . Equation (9).

The torque T _A generated by this motor can be expressed by the equation (10): T _A =Φ _A ·i ₁ d .

Therefore, when the torque command T and the magnetic flux command Φ are given, the equation (1) can be obtained from the equation (10), and the command i ₁ d can be obtained from this equation.

Further, the load command δ can be obtained from equations (10) and (9).

Furthermore, the above equation (3) is obtained from the above equation (8), and the command i ₁ q is obtained from this equation.

Since these commands i ₁ q and i ₁ d are orthogonal, their vector absolute value becomes the current amplitude command i ₁ , and this command i ₁ corresponds exactly to the torque command T.

Also, each phase at that time is the sum of the rotor rotation angle, the load angle, and the phase angle, so the above (4)
If the phase angle command θ obtained by the formula is used together with the current amplitude command i ₁ to calculate the current command i,
A torque T A that exactly matches the torque command _T is generated in the permanent magnet disc type synchronous motor 14,
At this time, the torque T _A does not lag behind the command T.

Therefore, as in this embodiment, the above equations (5) and (6)
The current commands iu, iv, and iw obtained by equation (7) are
When applied to the PWM inverter 12, extremely responsive and efficient motor control is possible.
Motor controllability is significantly improved.

Note that it is preferable that the torque command generator 32, magnetic flux command generator 34, and current command generator 36 of this embodiment are integrally configured by a processing device such as a microcomputer.

<<Effects of the Invention>> As explained above, according to the present invention, a current command is generated faithfully to the torque generation principle of a permanent magnet type synchronous motor, so it is possible to significantly improve its responsiveness and efficiency. becomes.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a device to which the present invention is applied, FIG. 2 is a sectional side view of a permanent magnet disk type synchronous motor, and FIG. 3 is an explanatory diagram of a two-pole model of the permanent magnet disk type synchronous motor. 10... Vehicle battery, 12... PWM inverter, 14... Permanent magnet disk type synchronous motor,
28... Rotation sensor, 30... Rotor position detector, 32... Torque command generator, 34... Magnetic side command generator, 36... Current command generator, 38... Divider, 40... Arithmetic unit (inverse sine function generator), 4
2... Arithmetic unit (cosine inverse function generator), 44, 46,
48... Arithmetic unit, 50... Arithmetic unit (tangent inverse function generator), 52... Arithmetic unit, 54... Vector multiplier.

Claims (1)

[Claims] 1. Torque component current command calculation means for calculating a torque component current command i ₁ d according to the formula i ₁ d = T/Φ using a torque command T and a magnetic flux command Φ; a primary inductance L of the motor; The load angle command δ is determined by the motor permanent magnet effective magnetic flux φ, torque command T, magnetic flux command Φ, and permanent magnet effective magnetic flux φ according to the formula δ=sin ^-1 (L/φ・T/Φ). Angle command calculation means, primary inductance L of the motor, magnetic flux command Φ,
A magnetic flux component current command calculation means for calculating a magnetic flux component current command i ₁ q using the load angle command δ and the effective magnetic flux φ of the permanent magnet according to the formula i ₁ q = (Φ − φ cos δ) / L, and a torque component current command i ₁ d, magnetic flux component current command
i ₁ q _{, the} ^{detected rotation} _angle θ ₀ of _the motor rotor ^, and the load angle command δ to determine _the current command i for the motor _. q)} A current command generator for a permanent magnet type synchronous motor, comprising: current command calculating means for calculating a current command according to the formula or an approximate formula thereof;