JPS605785A - Prescribed position stop control system of synchronous motor - Google Patents

Abstract

PURPOSE:To stop a synchronous motor at the prescribed position by a simple control system by fixing the pulse width of a pulse train of phase outputs, and applying repeatedly equal width pulses to the motor, thereby generating a stationary magnetic field from an armature winding. CONSTITUTION:An inverter 2 is controlled by a PWM controller 4. Digital outputs which are read out from waveform memories 61-63 in a PWM controller 4 are converted by D/A converters 71, 73 into analog sinusoidal signals. The signals are compared by comparators 81-83 with a triangular signal from a D/A converter 74 to produce unequal width pulse train. The inverter 2 is controlled by the pulse train. When a motor 3 is stopped, the pulse width of the pulse train of the phase outputs of the inverters 2 controlled by a PWM controller 4 is fixed to the pulse width of the phase outputs in the specific phase zone, and the equal width pulse is repeatedly applied to the motor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Q) The invention relates to a control method for stopping a power motor in a stereotactic manner.

Control method (J) to localize the motive (directly stop it) 1 f
, a position detector is provided in the rotating system of the electric motor, and the motor is stopped based on the starting signal ll'r. .

However, the above method has a major drawback in that it requires a positioning device. ! Q) When a position detector such as a magnetic type or an optical heavy type is added to a motor, the t4 configuration becomes complicated, large, and expensive. Additionally, the reconnaissance resistance of position detectors is generally inferior to that of wealth or motive itself. Therefore, high temperature/S
There are problems with K, which is used in harsh environments such as heavy duty and high humidity. In addition, the position detector and the control device must be connected with a cable. This sensor cable easily picks up noise, so countermeasures must be taken to prevent this.

As a fixed position stop control method that does not use a position detector, a method that uses a pulse motor is well known. rt is the number of pulses added to motor vri11 and the position (angle) of the motor
can be controlled using an oven loop method. but,
Pulse motors do not have a large torque capacity, so they cannot be used as power motors.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to provide a simple control system (2) that does not use a synchronous electric motor for power and a position detector that can obtain large torque. It provides an ili control method for discharging the slag at a fixed position.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows a control system in which a synchronous motor is operated one step using a PWM (pulse width modulation) inverter to which the present invention is applied.

The output of the rectifier 1 which rectifies the DC current source becomes the input to a power transistor inverter 20, and the AC output produced by the inverter 2 is applied to the loom winding of the synchronous power shell 3.

Inverter 2 &'! PWM control device t4v
Controlled by r. In this control device 4, an oscillator 41 oscillates at a frequency according to a frequency command signal vr from a command section 40. The oscillation output is output by two counters 42 and 42.
43, and are counted.

The digital counting output of the counter 42 becomes the address input of the sine wave waveform memories 61, 62, and 63 consisting of l(+I M. These three waveform memories 61, 62, and 63f
The same sine waveform is quantized and stored in f. However, the number of waveforms stored in each waveform memory 61, 62, and 63 is 12.
The phase difference is n by 0''.

The digital outputs read from the respective waveform memories 61, 62, and 63 are converted into analog sine wave signals r-s-1 by D/A converters 71, 72, and 73, respectively.

In addition, the count output of the counter 43 is stored in the triangular waveform memory 64.
Q) Address input. The digital output of the memory 64 is converted into an analog signal by a D/A converter 74 to obtain a triangular wave signal d.

FIG. 2 shows the relationship between the above-mentioned corrected wave signal r.8.t and the triangular wave signal dfll+. These signal frequencies vary proportionally to the oscillator 410 frequency. However, in this embodiment, the frequency of the triangular wave signal d is equal to the frequency of the sine wave signal r.
-8-t, 17) The frequency is set to be 6 times higher.

In addition, the heavy pressure command I/C from the command unit 40 becomes a gain control signal for each D/A converter 71, 72, 73, and the positive r1
i:f)lt No. 48 r -s -t, 0)l 1% is ko0) 1g @Cvr.

The sine wave signals r-s-t and the triangular wave signal d are compared by n comparators 81, 82, and 83, respectively, to produce an unequal width pulse train as shown in FIG. These comparators 81 and 8
The inverter 2 is controlled by the output r of 2.83, and the output pressure of the inverter 2 is PWM of the sine wave approximation shown in Fig. 3.
This becomes a signal and is applied to the electric motor 3ff.

The heavy pressure output of each phase of the inverter 2 becomes a sine wave approximation signal consisting of six unequal-width pulse trains in which one cycle is divided into six equal parts i and one pulse is included in each of the six phase intervals P1 to P6. Moreover, there is a phase difference of 120° between each phase.

The localization td stop control of this invention is performed as shown in the arrow. In other words, the pulse width of the pulse train of each phase output of the inverter 2 is fixed at 61, and the pulse width mK of each phase output in a specific phase interval of each phase interval P1 to P6 is fixed, and the pulse width of the pulse train is fixed to 61. 'l! is applied to motive 3.

As a result, a static magnetic field is generated from the Boisogo winding, and the motor 3 is stopped at a fixed position corresponding to the specific phase section.

For example, when raising three suspended aircraft in the phase interval P2 of FIG. 3, the inverter 2 outputs a pulse train of equal width as shown in FIG. 4 by the control described later.

The pulse width of each phase output in FIG. 4 is equal to nK of each phase output in phase section P2 of FIG. In this way, as shown in FIG.
From -8-T, a static magnetic field is generated in the direction indicated by arrow P2 (0), and the static force in the P2 direction moves relative to the rotor by one movement.

Further, when the motor 3 is stopped and started in the phase interval P3 of FIG. 3, the inverter 2 outputs the equal width pulse train shown in FIG. 5. As a result, a stationary force acts on the electric motor 3 in the direction of arrow P3 in FIG.

In this embodiment, the inverter 2 generates a pulse train of equal width as shown in FIG. 4 and FIG.
This is done by stopping the count operation in step 2.

When the counting operation of the counter 42 is stopped at a certain point T1, the addresses of the sine wave waveform memories 61, 62, and 63 are no longer updated. Therefore, as shown in Figure 7, D/
A converters 71, 72, 73θ] Outputs r, 8, and ↑ become a direct current with a continuous wave width f at time T1. This direct current and triangular wave d
are compared by the comparators 81, 82, and B3. Then, the equal width σ) becomes an inverter control signal, and the above-mentioned 111 W pulse train is generated from the inverter 2. Therefore, the counter 42 can be operated or stopped. The opening electric motor 3 can be rotated or stopped at any fixed position by can be increased.

As explained above in detail, according to the present invention, a simple oven loop control system is used to control fixed position stop of a large-torque power motor, without using a position detector that complicates the configuration. can be done.

[Brief explanation of drawings]

Figure 1 &! A configuration diagram of a control system to which this invention is applied, Fig. 2 is a control signal waveform diagram of the same control system during normal operation ((b) rotation drive), Fig. 3 is an output waveform diagram of the inverter during normal operation, and Fig. Figures 4 and 5 are inverter output waveform diagrams for fixed position stop control, Figure 6 is an explanatory diagram of the stopping action σ of the synchronous value motive, and Figure 7 is a control signal waveform diagram for fixed position stop σ]. . 2...Inverter, 3...Synchronization, motor, 4...
・pwulIill (foundation) device, 40... command department, 4
1... Trigger, 42° 43... Counter, 61,6
2.63...Sine wave waveform memory, 64...Triangular waveform memory, 71.72°73.74...1]/Af converter, 81,82.83...Comparator. Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) Using a pulse width modulation inverter, one cycle of the output voltage is divided into N equal parts (1) Each phase section ff
An alternating current flow similar to a sine wave consisting of an unequal 1-pulse train is generated, and this output drives the synchronous motor to rotate. α) Come on Vr; The pulse width is fixed to the pulse width of each phase output in the specific σ phase interval of N + fixed σ) in each phase interval, and equal-width pulses are repeated to obtain the same pulse width as described above. A fixed position stop control method for a synchronous motor, characterized in that a stationary grinding field is generated from an armature winding, and the motor is stopped at a fixed position corresponding to the specific phase section.