JPS6149680A - Current command generator for permanent magnet type synchronous motor - Google Patents

Abstract

PURPOSE:To remarkably improve the responsiveness and the efficiency by providing a current command calculator for generating a current command in accordance with a torque generation principle of a permanent magnet type synchronous motor. CONSTITUTION:A calculator 40 calculates a load angle command from the primary inductance L of a permanent magnet disc type synchronous motor 14, a permanent magnet effective magnetic flux phi and a torque component current command i1d. A calculator 42 obtains a value phicosdelta. The value phicosdelta is subtracted from a command phi in a calculator 44, and a magnetic flux component current command i1q is obtained in a calculator 46 by the primary inductance L of the motor 14. A current amplitude command is obtained in a calculator 48, and a phase angle is obtained in a calcultor 50. A phase angle command theta is obtained in a calculator 52. Current commands iU, iV, iW of the respective phases are obtained in a vector multiplier 54.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a current command generator for a device that controls the drive of a permanent magnet type synchronous motor.

(Prior art and its problems) Japanese Patent Application Laid-Open No. 48-1823 is known.

In a device that controls the drive AI of a permanent magnet type synchronous motor, a current command generator is used to control if! - The motor drive current is frill-controlled in accordance with the given current command.

However, since the current command was determined 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 responsiveness and efficiency of the motor.

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

(Structure of the Invention) In order to achieve the above object, the present invention provides a torque command T1
A torque component current command calculation means that calculates a torque component current command i1d according to the formula i + d - T / Φ based on the magnetic flux command Φ, and a load angle command based on the primary inductance L1 of the motor, the permanent magnet effective magnetic flux φ of the motor, and the torque command T1 magnetic flux command Φ. δ
The magnetic flux component current command 11q is calculated using the load angle command calculating means, the motor's primary inductance L, the magnetic flux command Φ, and the load angle command δ according to the formula: i+Q=(Φ−φcosδ)
/L Magnetic flux component current command calculating means, torque component current command ild, magnetic flux component current command! +Q, the detected rotation angle θ0 of the motor rotor, and the load angle command δ set the current command i to the motor as i −11+Ilq −e'
(θ0+δ+tan' (i Id/i +Q)
) or an approximate expression thereof, and current command derivation 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 the vehicle battery 10 is PW
It is converted into a three-phase alternating current by an M 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.

Since the rotor 18 is faced with a stone material formed in a substantially tray shape, a magnetic circuit 22 is formed by the magnetomotive force of a permanent magnet 20 inserted between the two.

Furthermore, a stator 24 is inserted into a gap formed on the circumferential side of the rotor 18, and a motor torque is generated by the flow of a current 26, and a reaction force is applied to the rotor 18.
is rotated.

Further, the rotation of the rotor 18 is detected by the rotation sensor 28, and by monitoring the detection signal, the rotor rotation angle θ0 is detected by the rotor position detector 3o in FIG.

In FIG. 1, this device is provided with a torque command generator 32 and a magnetic flux command generator 34, and their torque command T and magnetic flux command φ are supplied to a divider 38 of a current command generator 36.・It is.

In this U cutter 38, the torque component current command i1d is further transmitted to the arithmetic unit (inverse sine function generator) i1.
d −T/Φ ... is determined by the arithmetic processing of equation (1).

40, and the arithmetic unit (inverse sine function generator) 4
When J is set to 0, the primary inductance L of the permanent magnet disk type synchronous motor 4 and the permanent magnet effective magnetic flux φ are the commands i
1d, the load angle command δ becomes δ-5in'<1/φ-1
1d) -sin' (L/φ·T/′Φ)...It is determined by the arithmetic processing of equation (2).

The command δ obtained by the arithmetic unit (inverse sine function generator > 40) is supplied to the arithmetic unit (inverse cosine function generator) 42, where the value φC
O3δ is required.

The value φCO3δ is subtracted from the command Φ by J5 in the arithmetic unit 44, and this subtracted value is supplied to the arithmetic unit 46.

When the magnetic flux component current command i+Q is set as i+Q=(Φ
-φcosδ)/L... determined by equation (3).

Further, the Takyo component current command i+QJ and the torque component current command iId are supplied to an operator 48 and an operator (tangent inverse function generator) 50.

In the impedance generator 48, the current amplitude command Ji+Q21qld
2 is calculated, and the arithmetic unit 50 calculates the phase angle tan'l
(i ld /i Iq ) is required.

Moreover, the above phase angle tan' (i + d /i +
Q) C) The load angle command δ and the rotor detection rotation angle θ0 are supplied to the performance unit 52, and in this calculation unit 52, the phase angle command θ is calculated as θ−θ. +δ+01 ... determined by equation (4).

This phase angle command θ is supplied together with the current amplitude command 11 to a vector multiplier 54, and in this vector multiplier 54, current commands iu, iv,
iw is iu= l+Q 1ql sin (θ.+δ+θ1)...Equation (5)%Equation%+01+2π/'3)...l'
(6 formula iw= + I Q +I
IT″″′sin (θ+δ+01+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 #J currents.

This embodiment has the above-mentioned configuration, and its operation will be explained below: J! I will clarify.

As can be 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 motor 14, the torque is generated as follows.

In Figure 3, the markers (Q, d) are the effective magnetic flux Φ^
The magnetic flux φ^ is 1q due to the permanent magnet.
It is being

At this time, the magnetic flux components in each direction are as follows: ΦA=φA008δ+Li+Q Equation (8) 0−φsinδ+Li 1 d =−(9)
It is possible to express it by the formula.

And the torque T^ generated by this motor is TA-ΦA
-1Id...It can be expressed by equation (10).

Therefore, when the torque command T and the magnetic flux command Φ are given, the equation (1) can be expressed as 1rI from equation (10).
Therefore, the command i1d can be obtained from this equation.

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

Furthermore, the above-mentioned equation (3) is removed from the above-mentioned equation (8),
Command i+Q is obtained from this equation.

Since these commands i+Q and ild are orthogonal, their vector absolute value becomes the current amplitude command 11, and this command II
corresponds precisely to the torque command.

, :;5
1 to calculate the current command 1, a torque TA that exactly matches the torque command T is generated in the permanent magnet disk type synchronous rotor 14, and this torque T
A never lags behind command T.

Therefore, as in this embodiment, the current command iu is determined by the equations (5), (6), and (7).

When iv and iw are given to the PWM inverter 12,
Motor control with extremely high responsiveness and efficiency becomes possible, and motor controllability is significantly improved.

Note that the torque command generator 32 of this embodiment. Magnetic flux command generator 34. It is preferable that the Fi flow command generator 36 be constructed integrally with processing equipment 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. .

[Brief explanation of the drawing]

Fig. 1 is a block configuration diagram of a device to which the present invention is applied, Fig. 2 is a side sectional view of a permanent magnet disk type synchronous motor, and Fig.
The figure is an explanatory diagram of a 2fi model of a 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 flux Command generator 36... Current command generator 38... Divider 42... Arithmetic unit (cosine inverse function generator) 44.46.4
8... 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 that calculates the torque component current command i_1d according to the formula i_1d=T/Φ using the torque command T and magnetic flux command Φ, the motor's primary inductance L, the motor's permanent magnet effective magnetic flux φ, and the torque command The load angle command δ is calculated as δ=sin＾−＾1(L/
The magnetic flux component current command i_1q is calculated using the load angle command calculation means obtained according to the formula: i_1q=(Φ- φcosδ)/L magnetic flux component current command calculating means, torque component current command i_1d, magnetic flux component current command i_1q,
Based on the detected rotation angle θ_0 of the motor rotor and the load angle command δ, the current command i for the motor is i=√{i_1d^2+i_1q^2・e^j[θ_0
+δ+tan＾−＾1(i_1d/i_1q)]} or an approximate expression thereof; current command calculation means for calculating the current command according to the equation or an approximate equation thereof; and a current command generator for a permanent magnet type synchronous motor.