JPS62217891A - Control system of commutatorless motor - Google Patents

Abstract

PURPOSE:To control a lead angle of a converter at side of a motor accurately, by a method wherein signal multiplied from output signal of a position detector mounted on a synchronous machine is used as input current of a pulse distribution circuit. CONSTITUTION:One input of a phase comparator 52 is a position detector signal (a) mounted on a synchronous machine, and another input is output signal (h) of a frequency dividing circuit 55. The phase comparator 52 detects phase difference of the two input signals, output corresponding to the phase difference is smoothed by a filter 53 and then becomes input signal of a VCO 54. The VCO 54 oscillates at frequency depending on the input signal, and the output is inputted to a counter 56 and the frequency dividing circuit 55. Frequency dividing ratio of the frequency dividing circuit 55 is dependent on resolving power of lead angle in the pulse dividing. Output (g) of the VCO 54 is used in place of pulse generator signal in the pulse dividing circuit.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a so-called synchronous motor in which a synchronous motor is driven through an inverter consisting of forward and reverse converters, and commutation of the reverse converter is performed by the back electromotive force. Concerning a control method for a commutatorless motor.

[Conventional technology]

FIG. 4 is a schematic diagram showing a general example of a commutatorless motor control system. In the figure, 1 is a power supply side converter (forward converter), 2 is a motor side converter (inverse converter), 3 is a synchronous motor, 4 is a position detector (PS), and 5 is a control device.

In other words, as is well known, commutatorless motors
For example, a thyristor inverter (variable voltage variable frequency converter) consisting of a forward converter 1 and an inverse converter 2, a synchronous motor 3, a rotor magnetic pole position detector (PS') 4, and a control device 5 that performs ignition control. By replacing the commutator and brushes of the DC motor with a thyristor and a position detector, the synchronous motor has the same control characteristics as a DC motor, and the rotor magnetic pole position of the synchronous motor 6 is is detected by the position detector (PS) 4, and the inverse converter 2
It generates torque by switching the direction and phase of the armature current.

By the way, in such a commutatorless motor, it is necessary to control the firing advance angle (β) of the um machine side converter (inverse KM device) in order to perform constant margin angle control, but the applicant has The following Kihalus generator (PL) is used as a reference quantity for lead angle control.
Japanese Patent Application No. Sho 59-145944 proposes a method using pulses from O) (hereinafter also simply referred to as the "proposed method").

Note that this PLG pulse is also used as a speed feedback amount when performing speed control, and is particularly suitable for a DDC (direct digital control) method using a digital processing device a (hereinafter simply referred to as a microcomputer) such as a microcomputer. There is.

FIG. 5 is a schematic diagram showing the proposed system, FIG. 6 is a block diagram showing 1,44 components of the pulse distribution circuit in FIG. 5, and FIG. 7 is a waveform diagram of each part for explaining its operation.

As is clear from FIG. 5, compared to the general method shown in FIG. 4, this proposed method is characterized by the provision of a PLG6, and the pulses from this PLG6 are The pulse is guided to a pulse distribution circuit to perform constant margin angle control.

That is, the pulse distribution circuit shown in FIG. 6 is provided in the control device 5 shown in FIG.
, a comparator 57, a buffer 58, etc. A pulse signal from the PLG 6 is input to the color/receiver 56, and this is counted as shown in FIG. 7(a). Comparator 5
7, when this count value matches the value corresponding to the interval from the current ignition timing to the next ignition timing, which is detected by the microcomputer 51, the microcomputer 51 sends an interrupt signal [as shown in FIG. 7(b)]. At the same time, a clear signal is given to the counter 56, and the counter 56 is cleared as shown in FIG. 7(a).

The microcomputer 51 generates an ignition pulse e as shown in FIG. 7(c) based on the interrupt signal f, and sequentially supplies it to the switching elements via the packer 58. The value Δα set in the comparator 57 from the microcomputer 51 is
From the lead angle command value β and the actual firing value β, the microcomputer 51 calculates Δα−60°e′+(β”−β). Therefore, the input signal of the counter 56 determines the lead angle resolution. It will be decided.

[Problem that the invention seeks to solve]

However, since it is difficult to mechanically attach the above-mentioned PLO to large-capacity electric motors such as pumped storage generators, there are cases where only a position detector can be attached. With the id and h logic signals of this position detector,
Generally about 60°el or 120°el mn14
Therefore, with this alone, the amount of information tK necessary for performing not only constant margin angle control but also advance angle control will be insufficient. In addition, in applications where constant margin angle control is not required,
Pulse distribution can be performed based on the signal from position detection, but an advance angle adjustment function may be required to correct position detector adjustment errors.

In other words, although advance angle control would be impossible without PLO pulses, due to installation constraints, PLO pulses cannot be controlled in this way.
There is a problem that it may not be possible to install the .

Therefore, it is an object of the present invention to provide a control system for a large-capacity synchronous machine in which it is difficult to install a PLG, in which highly accurate advance angle control can be performed using only position detector signals.

[Failure to solve the problem]

A frequency multiplier circuit is provided that multiplies the frequency of the output signal from the position detector.

[Effect]

By multiplying the signal from the position detector by the frequency multiplier circuit and using this multiplied signal to control the lead angle of the converter on the motor side, the lead angle can be adjusted even in large-capacity synchronous motors where it is difficult to install a PLO. To be able to control with high precision.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an embodiment of the invention. In the figure, 52 indicates two input signals a.

53 is a filter for smoothing the output of the phase comparator, 54 is a VCO (voltage controlled oscillator), 55 is a frequency dividing circuit, and the other parts are the same as in FIG. 6. .

One input of the phase comparator 520 is the position detector signal a attached to the synchronous motor 3, and the other input is the output signal of the frequency dividing circuit 55. The phase comparator 52 is
A phase difference between the two input signals is detected, and an output corresponding to this phase difference is smoothed by a filter 53 and then becomes an input signal to the VCO 54.

The VCO 54 oscillates at a frequency determined by the input signal,
The output is input to a counter 56 and a frequency divider circuit 55.

The division ratio N of the frequency dividing circuit 550 is the lead angle β in pulse distribution.
Determined by the resolution of The output of the frequency divider circuit 55 is locked to the same frequency fs as the other input of the phase comparator 52, which is the position detector signal. Therefore, the output g of the VCO 54 has a frequency of (NXf,), and this signal g is used in place of the input pulse generator signal in the proposed pulse distribution circuit shown in FIG.

FIGS. 2 and 3 show the relationship between the position detector signal a and the output signal g of the vC054. FIG. 2 shows a case in which the position detector output signal is directly used as input to the phase comparator 52.
The resolution of the advance angle determined by the input signal g of the pulse distribution circuit is 360°et/N. Since position detectors are usually installed for 3 or 6 phases, a signal a as shown in Figure 3 (a) is obtained by logically synthesizing these position detector signals.
' can also be used as the input of the phase comparator, in which case the resolution of the advance angle I would be 120°"7M.

In other words, the method shown in Figure 3 contains three times as much information as the method shown in Figure 2, so when compared in terms of responsiveness, it is
The method shown in the figure is a better method. Note that the pulse distribution method using the output signal g of the VCO 54 as input is the same as explained in FIG. 6, so the explanation will be omitted.

A multiplier circuit (for example, a phase-lock Druze CPLL) is used to convert the position detector signal attached to the motor into the above-described circuit.
By using the frequency-multiplied signal in the pulse divider as the input signal of the pulse divider, it is possible to create a large-capacity synchronous motor that cannot be attached due to mechanical constraints to the conventional pulse generator used as the input of the pulse divider. (Also, it is possible to perform advance angle control with high precision.

〔Effect of the invention〕

According to this invention, a signal obtained by multiplying the output signal of a position detector attached to a synchronous motor is used as a human input signal for the pulse distribution circuit. Even in large-capacity synchronous motor control that cannot be performed, the advantage is that the lead angle β of the electric TtJJJ machine-side converter can be controlled with high accuracy.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Figs. 2 and 3 are waveform diagrams of various parts to explain the operation of Fig. 1, and Fig. 4 is a general diagram of a non-commutator motor control system. 5 is a schematic diagram showing a proposed method, FIG. 6 is a block diagram showing a specific example of the pulse distribution circuit used in FIG. 5, and FIG. 7 explains its operation. It is a waveform diagram of each part for. Code explanation 1...Power side converter (forward converter), 2...
...Motor side converter (device changer), 5...Synchronous motor, 4...Position detector (PS), 5...
...Control device, 6...Pulse generator (
PLG), 51... Calculation side 51 device (microcomputer), 52... Phase comparator, 53...
... Filter, 54 ... Voltage controlled oscillator (VCO), 55 ... Frequency divider circuit, 56 ...
... Counter, 57 ... Comparator, 58 ...
··buffer. Agent Patent Attorney Akio Namiki Agent Patent Attorney Kiyoshi Matsuzaki Figure 1 Figure 2 Figure 3 Figure 6 Figure 7

Claims (1)

[Claims] 1) An arithmetic and control device, a counter that counts a predetermined clock signal to determine the ignition pulse interval, and a current ignition timing that is calculated by the arithmetic and control device from a control advance angle command value. and a comparator that compares the counter value with a value corresponding to the interval from 1 to the next ignition timing, and outputs an interrupt signal to the arithmetic and control unit and a clear signal to the counter when the two match, In a control method in which a firing pulse to be applied to a switching element of a converter main circuit is determined by an arithmetic control unit from the interrupt signal to control the advance angle of a commutatorless motor, a position detector attached to the commutatorless motor is used. 1. A control system for a non-commutated motor, characterized in that a multiplier circuit is provided for multiplying the frequency of an output signal from a non-commutator motor, and the output of the multiplier circuit is used as a clock signal for the counter. 2) A control method for a non-commutator motor according to claim 1, wherein the multiplier circuit is a phase-locked loop (PLL) circuit.