JPH0799950B2 - Control system of synchronous motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for a synchronous motor which requires many detection signals such as field pole position detection signals and speed detection signals.

[0002]

2. Description of the Related Art A control system for controlling a synchronous motor with good responsiveness detects a field pole of the synchronous motor and controls a current phase in synchronization with a magnetic pole position, thereby achieving extremely excellent torque control and speed control. In the control of the synchronous motor that can be achieved, a pulse encoder and a resolver are used for field pole position detection and speed detection, and many signal lines are required.

FIG. 8 shows a control system diagram of a conventional typical synchronous motor. In order to control the synchronous motor with extremely excellent responsiveness, it is necessary to pass a current through the magnetic flux generated from the field pole provided in the rotor of the synchronous motor and the stator winding that intersects with the magnetic flux. Is.

In FIG. 8, the detection signal of the field pole position detector 2 for detecting the position of the field pole of the rotor attached to the synchronous motor 1 is taken into the current phase controller 7, and the speed controller 5 is loaded. It is possible to control the phase and magnitude of the electric current by multiplying the output, that is, the torque command. These signals are given to the current controller 9, and the current actually supplied to the synchronous motor 1, that is, the feedback signal of the current, is compared and calculated, and then the power is supplied by the signal to the PWM controller 10 and the transistor base drive circuit 11. The inverter unit 12 provided for the control is controlled to supply the optimum current to the electric motor to enable torque control and speed control. In FIG. 8, 4 is a speed setter, 5 is a speed controller, 6 is a speed converter, 7 is a current phase controller, 8 is a torque current calculator, 9 is a current controller, and 1 is a current controller.
Reference numeral 0 is a PWM controller, 11 is a transistor base drive circuit, and 12 is an inverter unit. Although the field pole detection signal line and the speed detection signal line are shown as one line in the figure, these are three pairs or more. However, it is omitted for convenience.

As described above, in order to control the synchronous motor according to the conventional technique with good characteristics, the signal lines for detecting the magnetic field pole position attached to the synchronous motor 1, the normal U phase, V phase, and W phase 3 are used.
In addition to 3 pairs (6) of multiple phase signal lines, in addition to 2 or 3 pairs of signal lines for speed detection, usually φA, φB, (φZ), Power supply line, multiple wires are required. Further, even in the method of detecting these two signals by the resolver, four pairs (8) or more signal lines including the power supply line are required.

[0006]

However, with the miniaturization of mechanical devices as in recent years, the advent of control devices with or without wiring, including control devices and electric motors, has been awaited. Ultimately, it is most desirable to be sensorless, but the current technology does not provide sufficient characteristics. Incidentally, the conventional system using the DC motor has the merit that it can be realized by only one pair (two) of the analog tacho signal line which is the speed feedback signal as the signal line. In the current situation where the child) is a problem from the aspect of maintenance, it cannot be accepted in the market as an optimal system.

[0007]

In consideration of the above points, the present invention intends to control the synchronous motor with the same number of wires as the DC motor without impairing the characteristics of the synchronous motor.
That is, in the present invention, the field pole position of the synchronous motor is detected, and the current control synchronized with the corresponding field pole position enables the torque control and speed control of the synchronous motor. A plurality of field pole position detection signals corresponding to a plurality of windings determined by the number, so-called digital signals, are converted into analog quantities and combined to output as one signal in analog quantity. It employs a detector that can capture the velocity detection signal by superimposing it on the line.

[0008]

Thus, in the present invention, by adopting a detector having an output obtained by converting a plurality of field pole position detection signals and speed detection signals into one signal, the characteristics of the synchronous motor are impaired with only one signal line. Without this, torque control and speed control can be achieved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a system diagram showing the flow of field pole position detection signals and speed detection signals according to the present invention, and FIG. 2 is a system diagram showing the configuration of signal lines of a detector. According to this, conventionally, the signals of the magnetic pole position detector 2 and the velocity detector 3 are U,
The V, W signals and signals such as φ _A are output through a plurality of individual signal lines, but in FIG. 3, these signals are output as a single signal by a pair of signal lines. That is, 3 pairs (6 lines) of field magnetic pole detection signals and 4 pairs (8 lines) including the power supply line are required, but the present invention can be realized with 1 pair (3 lines). Further, as will be described later, by further adding the component of the speed detection signal on this signal, the speed detection signal line 3 pairs (6 lines) or 4 pairs (8 lines) becomes unnecessary. As described above, according to the present invention, the signal lines of ten or more can be realized by the three signal lines.

FIG . 3 shows a three-phase winding, one-pole motor shaft of a two-pole machine.
It represents the field magnetic pole position detection signal at the time of turning, U,
Three 120 ° output depending on the V and W phase winding positions
It is a phase difference signal. Traditionally, these signals are separate signals
It was supplied using a wire, but in this system it is shown in FIG.
The analog type current adder is used to output three phase difference signals
4 wave heights as shown in Fig. 4b
Characterized by converting into one analog signal with a value
To do. A specific example of the circuit is shown in FIG. U
SIG, VSIG, and WSIG are input resistors of the adder shown in FIG.
Determined by anti (R, 4 / 3R.2R) and feedback resistor 2R of adder
It is added at the whole magnification. In this example, 2x, 1.5x,
Since the voltage signals of FIG. 3 are added as 1 ×, the voltage signal of FIG.
Voltage signals with peak values of 2Va, 1.5Va, Va
Is output to the current type adder of FIG. Therefore, that
The addition result VOUT is the field pole position every 60 ° as shown in FIG. 4b.
It becomes one analog signal with different peak value according to the position .

On the other hand, as a method of further reducing the signal lines,
To the analog magnetic field position detection signal
To the pulse signal of the speed output according to the speed of the motor
It is to be superimposed. Specifically, U shown in FIG.
The voltage signal VOUT that can identify the magnetic pole positions of V and W
The speed profile detected according to the motor speed shown in FIG.
The loose signal ΦA is multiplied by the multiplier of FIG.
You can The pulse signal ΦA is 1 or 0 (zero)
Of the signal fO of FIG.
The UT also has a peak value corresponding to the field pole position shown in FIG. 6a.
In addition, a pulse signal consisting of a frequency corresponding to the motor speed
It can be taken out as a sequence (incremental signal).
Wear.

The magnetic pole position and velocity thus obtained are
The pulse signal containing the information is the current of FIG.
Current phase control that can be transmitted to the phase controller 7 and speed converter 6
In the device 7, the peak value of the transmitted signal and the preset value are set.
Same reference values as in Fig. 4b for U, V and W phase windings
By comparing (crest value) with the
The flow phase can be obtained again. On the other hand, speed converter
In 6, the frequency of the transmitted signal is changed to frequency / voltage.
Knowing the actual motor speed by converting using
You can This detected signal is the speed feedback signal
It is sent to the controller 5. In the speed controller 5, the speed setter 4
And the feedback signal obtained by the speed converter 6
Compare and calculate the required torque current, and use it as the torque command.
It is sent to the torque current calculator 8. In the torque current calculator 8,
This torque command and the optimum current obtained by the current phase controller 7
Multiply by the phase signal and increase the current required for each U, V, W phase.
Send to the current controller 9 as a current command with a magnitude and phase
And the synchronous motor is controlled. In addition, the star after power on
Control based on the field pole position signal, the motor shaft
Incremental proportional to speed after one revolution
Derive the current phase from the pulse signal to obtain a finer control.
You can also take control.

Thus, by passing this signal through the current phase controller 7 and the speed converter 6 shown in FIG. 8 and extracting and controlling it as a current phase signal and a speed feedback signal, high-performance speed control of the synchronous motor, etc. Can be realized.

[0014]

As described above, according to the method of the present invention, by using a detector having an output obtained by converting a plurality of field pole position detection signals and velocity detection signals into one signal, only one signal line is required. The control can be performed without impairing the characteristics of the synchronous motor. In addition, the conventional sensorless system cannot make full use of the characteristics of the synchronous motor with the current technology, but the method of the present invention enables the use of a detector with a small number of signal lines, and can bring out the characteristics originally possessed by the synchronous motor. Therefore, it is possible to exhibit extremely excellent characteristics exceeding those of the DC motor.

[0015]

[Brief description of drawings]

FIG. 1 is a circuit system diagram in which the signal flows of a field pole position detector and a speed detector, which are objects of the present invention in the control system diagram of the conventional synchronous motor of FIG. 8, are extracted.

FIG. 2 is a circuit system diagram showing a configuration of a signal line of a detector which is one of the objects of the present invention.

FIG. 3 is a waveform diagram of a field magnetic pole position detection signal of each three phases.

FIG. 4a is a waveform diagram in which the output signals of FIG. 3 are provided with different peak values for each phase.

FIG. 4b shows an output waveform when the outputs of FIG. 4a are combined.

5 is a circuit system diagram showing an example of the waveform synthesis method of FIG. 4a.

FIGS. 6a and 6b are waveform diagrams obtained by superimposing a velocity detection signal on a field magnetic pole position detection signal and extracting in pulse form with the same waveforms as FIGS. 4a and 4b.

7 is a circuit diagram showing an example for superimposing the incremental pulse of FIG. 6b on FIG. 4b.

FIG. 8 is a circuit system diagram of a general synchronous motor control system.

[Explanation of symbols]

1 Synchronous Motor 2 Field Magnetic Pole Position Detector 3 Speed Detector 5 Speed Controller 6 Speed Converter 7 Current Phase Controller 8 Torque Current Calculator 10 PWM Controller 11 Transistor Base Drive Circuit 12 AC-DC-AC Inverter Unit

Claims (1)

[Claims] 1. A detects the field pole position of the synchronous motor, the control apparatus performs current control in synchronism with the corresponding field pole position, corresponding to a plurality of windings is determined by the number of phases and number of poles of the synchronous motor The plural field pole position detection signals, so-called plural digital signals, are added by the current type adders having different gains.
A single analog signal that has multiple peak values when arithmetically synthesized.
Detector that outputs the signal after conversion into a signal, and a motor on the signal
Pulse signals proportional to the speed of
It is converted into a pulse signal with a peak value of
In addition to the report, a control system for a synchronous motor, which enables control of the torque and the speed of the synchronous motor by using a detector which converts and outputs a signal having speed information .