JPS6339484A - Controller for brushless motor - Google Patents

Abstract

PURPOSE:To precisely conform the position of a magnetic pole to the phase of armature currents by adding a numeric value set to an offset means to the information of the position of the magnetic pole. CONSTITUTION:A signal displaying difference with actual speed of target speed from an integrating amplifier 4 and pole-position information from an adding means 10 are inputted to a three-phase distribution circuit 5, and a brushless motor 2 is supplied with armature current information having amplitude corresponding to target torque through current amplifiers 14-16 at every phase. When a fundamental wave outputted from an ROM 9 and the position of an actual magnetic pole are displaced, a numeric value corresponding to the phase shift is set to an offset means 12. Since the numeric value is added to pole- position information in the adding means 10, the fundamental wave generated from the ROM 9 is phase-shifted, and conformed to the position of the magnetic pole.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for exciting a brushless motor.

[Conventional technology]

Brushless motors are equipped with a rotor position detection sensor that detects the rotor position on the stator side, and the position signal output by the rotor position detection sensor is part of the information that controls the energization of the stator windings. It is one. In other words, the position signal output by the rotor position detection sensor has significance as a basic signal for knowing the rotor's magnetic pole position, and the motor control device controls the armature current to the motor according to the rotor's magnetic pole position. is supplied to. Therefore, it has been necessary to strictly adjust the attachment of the rotor position detection sensor in relation to the magnetic pole position of the rotor.

[Problem that the invention seeks to solve]

However, it is very difficult to mechanically accurately adjust the position of the rotor position detection sensor, and the adjustment has not always been made sufficiently.

In addition, it is difficult to correct the position of the rotor position detection sensor once it has been adjusted and fixed, especially in types where the motor and rotor position detection sensor are integrated, readjusting the rotor position detection sensor. is nearly impossible.

[Failure to solve the problem]

The brushless motor control device of the present invention was made in view of the above problems, and includes an offset means that can set and hold an arbitrary value, and a magnetic pole position that is basic information for determining the phase of the armature current. and addition means for adding the output value of the offset means to the information.

[Effect]

If the installation of the rotor position detection sensor is incompletely adjusted, setting an appropriate value in the offset means will add the value set in the offset means to the magnetic pole position information G and determine the magnetic pole position. The position information is corrected, and the magnetic pole position and armature current phase match accurately.

〔Example〕

Hereinafter, the present invention will be described in detail along with examples.

The figure is a block diagram showing one embodiment of the present invention.

The speed command means 1 is means for giving a target speed to the three-phase brushless motor 2, and its output signal, the speed command signal, is inputted to the adder/subtractor 3 as an addition element. The actual speed signal output from the sensor 13 is input to the adder/subtractor 3 as a subtraction element.

The sensor 13 is integrally attached to the brushless motor 2 and is a means for detecting the rotational speed and position of the rotor, and the rotational speed and position of the rotor detected by the sensor 13 are each an actual speed signal. and output as a position signal.

A specific example of such a sensor 13 is a resolver.

The output of the adder/subtractor 3 indicates the difference Δω between the target speed and the actual speed, and is input to the integrating amplifier 4. Integrating amplifier 4 is
This is means for outputting a target torque 7'q') based on the input Δω, and the target torque Tq'' is input to the three-phase distribution circuit 5.

Three-phase distribution circuit 5 includes D/A converter 6.7.8 and ROM
9, which is a means for distributing and outputting armature current information according to the target torque Tq1 for each phase.

In the ROM 9, sine waves whose phases are shifted by 120 degrees are written for one cycle each as U phase, ■ phase, and W phase. That is, when the address value is smoothly increased in the ROM 9, one cycle of sine waves corresponding to the U phase, ■ phase, and W phase is output in the form of a digital signal. Therefore, if such addressing is periodically and continuously repeated, a continuous sine wave can be obtained for each phase. The U-phase sine wave is sent to the D/A converter 6,
■The phase sine wave is D/A converter 7, and the W phase sine wave is D/A converter 7.
Each signal is input to a converter 8 and converted into an analog signal. Note that in each D/A converter 6 to 8, an integrating amplifier 4
Multiplication by the target torque Tq9 from is also performed at the same time.

The outputs of the A/D converters 6 to 8 are respectively connected to current amplifiers 14 to 14.
The current is amplified by 16 and supplied to each phase of the brushless motor 2 to drive the motor.

Addressing to the ROM 9 is performed by an adding means 10. The adding means 10 is a means for adding the digital magnetic pole position information given from the magnetic pole position detection circuit 11 and the digital correction information given from the offset means 12. The magnetic pole position detection circuit 11 is a means for detecting the positional relationship (i.e., electrical angle) of the magnetic poles between the stator and rotor of the brushless motor 2 based on the position signal output by the sensor 13. The position is displayed numerically and output as digital magnetic pole position information. The offset means 12 outputs a preset constant as correction information, and this constant can be set and held by a date switch or set and held in a writable storage means. can.

Next, the operation of the control device of this embodiment configured as described above will be explained. Assume now that the offset means 12 is set so that its output is zero. Speed command means 1
When a speed command signal is output from the sensor 13, it is compared with the actual speed signal from the sensor 13, and the difference Δω is input to the integrating amplifier 4. Integrating amplifier 4 supplies target torque Tq'' corresponding to Δω to three-phase distribution circuit 5. Three-phase distribution circuit 5 outputs armature current information having an amplitude according to target torque Tq'' for each phase. Armature current information is current amplifiers 14 to 16
The signal is amplified and applied to the brushless motor 2. At this time, the fundamental wave of each phase in the three-phase distribution circuit 5 is given by the ROM 9, and since the output of the offset means 12 is zero, the phase of this fundamental wave is given by the magnetic pole position information output from the magnetic pole position detection circuit 11. ing. Therefore, if the mounting of the sensor 13 is insufficiently adjusted and there is a shift in the magnetic pole position information, the phase of the fundamental wave output from the ROM 9 will also shift and will not accurately match the magnetic pole position.

Therefore, if the position of the fundamental wave output from the ROM 9 and the actual magnetic pole deviates, a numerical value corresponding to the phase deviation is set in the offset means 12 with respect to the magnetic pole position information. Then, the value is added to the magnetic pole position information in the adding means 10, so that the fundamental wave generated by the ROM 9 is phase-shifted and becomes coincident with the magnetic pole position.

From now on, unless the setting value of the offset means 12 is changed,
Armature current with accurate phase is supplied to the brushless motor 2.

〔Effect of the invention〕

As explained above, according to the brushless motor control device of the present invention, when the installation of the rotor position detection sensor is incompletely adjusted, when an appropriate value is set in the offset means, the magnetic pole position information is set to the corresponding value. is added to correct the magnetic pole position information, and the magnetic pole position and the phase of the armature current match accurately.

That is, even if the mechanical adjustment at the time of attaching the rotor position detection sensor is not perfect, it can be easily corrected.

Therefore, the position adjustment during installation may be imperfect to some extent, and therefore the installation is facilitated. Moreover, the correction by the offset means allows the magnetic pole position and the phase of the armature current to match more accurately than when conventional mechanical adjustment alone is used.

[Brief explanation of the drawing]

The figure is a block diagram showing one embodiment of the present invention. 1... Speed command means, 2... Brushless motor, 3
... Adder/subtractor, 5... Three-phase distribution circuit, 6 to 8...
D/A converter, 9...ROM, 10...addition means,
11... Magnetic pole position detection circuit, 12... Offset I.
Means, 13...sensor.

Claims (1)

[Claims] Equipped with a rotor position detection sensor that detects the rotational position of the rotor, creates magnetic pole position information that numerically indicates the positional relationship between the magnetic poles of the rotor and stator from the output of the rotor position detection sensor, and fixes it from the magnetic pole position information. In a brushless motor control device that determines the phase of an armature current with respect to a child winding, an offset means that can set and hold an arbitrary value;
A brushless motor control device comprising: adding means for adding an output value of the offset means to the magnetic pole position information.