JPS59204457A - Rectification compensator of dc electric machine - Google Patents

Abstract

PURPOSE:To improve the rectifying performance by comparing a detection voltage by a detecting brush with a command value, f/V-converting the compared output, and controlling a current of an auxiliary winding in response to the output, thereby reducing the current pulsation of the auxiliary winding. CONSTITUTION:A detection voltage by a detecting brush 12 is inputted through an insulating amplifier 15 to a comparator 16. This comparator 16 compares the detected voltage with a command value (a), and outputs a detected voltage higher than the command value (a). This output is waveform-shaped by a waveform shaper 17, and converted by a f/V converter 18 into a DC voltage. The current of an auxiliary winding 5A is supplied in response to the DC voltage of the converter 18 by a power amplifier 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a DC machine, and more particularly to a rectification compensation device for a swing DC machine that improves the rectification effect.

[Background of the invention]

DC machines have a phenomenon in which the position of the spark-free zone shifts depending on the rotational speed and the state of film formation on the commutator surface, making it difficult to achieve spark-free commutation over the entire operating range. As a countermeasure for this,
A method has been proposed in which the rectification state is detected and the interpolation magnetomotive force is adjusted according to the rectification state to achieve sparkless commutation. Examples thereof are shown in FIGS. 1 to 3. Figure 1 shows an exploded view of the stator and rotor of a DC machine. A main pole iron core 2 and a commutating pole iron core 4 are attached to the inner circumference of the yoke 1, and the main pole iron core 2 has a field winding 3 that generates all of the main magnetic flux, and a compensation that compensates for bias in the main magnetic flux due to armature reaction. A winding 6 is provided.

On the other hand, the commutator core 4 has a commutator winding 5 that produces rectified magnetic flux.
The commutator winding 5 is connected in series with the armature and the compensation winding 6 (FIG. 2). An auxiliary winding 5A' is wound differentially with the commutator winding 5 on the inner circumferential tip side of the twisted commutator core 4.
(Z is provided. The magnitude of the rectified electromotive force induced in the rectifier coil of the armature winding 9 provided in the slot 8 of the armature core 7 changes by controlling the amount of current in this auxiliary winding 5A. FIG. 2 is a circuit block diagram of a rectification compensator that supplies current to the auxiliary winding according to the rectification state from an external power supply.

In FIG. 2, armature current 1y is applied to brush 1 (1').

It flows through the commutator 11 to the armature winding 9, and further flows from the brush 10 through the compensation winding 6 and the commutator winding 5. The current iP of the auxiliary winding 5A is detected by a brush 12 that detects the voltage between the brushy commutator pieces near the brush outlet where the result of rectification compensation is good or bad is detected, and the power amplifier 13 detects this detected voltage V.
1° is supplied according to b. In other words, in this method, if the detection voltage Vb is within ±3V, the brush does not generate sparks, so the current is applied to the auxiliary winding 5A according to the detection voltage Vb so that the voltage is always within ±3V. The purpose is to fully adjust the interpolation magnetomotive force by flowing iP to achieve sparkless rectification.

However, as a result of rectification compensation using this method,
Although the auxiliary magnetomotive force can be adjusted in accordance with the rectified state, that is, the detected voltage Vb, there is a problem in that the current ip of the auxiliary winding 5A has large pulsations.

FIG. 3 shows an example of operating characteristics. When the rotation speed N' (i = constant and the armature current IM is changed at point A1, the current IP in the auxiliary winding follows the change in the armature current Iy, but the current pulsation is large. .

This is because the rectifying performance of each rectifying coil is different.
This is because the detected voltage Vb varies for each commutator piece, and the current is controlled according to the detected voltage Vb for each commutator piece. If this current pulsation is large, the commutating magnetic flux will pulsate, and due to the eddy current generated in the commutating magnetic path, the commutating magnetic flux will be delayed in time with respect to changes in the armature current, which will actually reduce the rectification performance. There are drawbacks. -! Furthermore, if a smoothing reactor 14 is inserted as shown in FIG. 2 to suppress current pulsations, there is a drawback that the rectification compensator becomes large.

[Object of the Invention] The object of the present invention is to reduce the current pulsation of the auxiliary winding to suppress the pulsation of the interpolation magnetic flux, and to completely eliminate the smoothing reactor, thereby obtaining a compact and good rectifying performance for a DC machine. To provide a compensation device.

[Summary of the invention]

In the present invention, if the detection voltage Vb by the detection brush exceeds ±3V, sparks are generated from the brush, so the detection voltage Vbf is compared with the command value lower than ±3V, and the entire waveform of the detection voltage higher than the direct command is shaped. Input to f/V converter, this f/■
The present invention is characterized in that the current in the auxiliary winding is controlled according to the output of the converter to reduce current pulsations in the auxiliary winding and to obtain good rectification performance.

[Embodiments of the invention]

Embodiments of the present invention will be described using FIGS. 4 to 6. FIG. 4 shows a circuit block diagram of a rectification compensator according to the present invention that supplies current to the auxiliary winding according to the rectification state using an external power source.

In Figure 4, ′! 1! The Isogo current IM flows along the same path as in the conventional case. On the other hand, the voltage Vb detected by the detection brush 12 is input to a comparator 16 via an isolation amplifier 15 in order to isolate it from the main circuit of the DC machine. This comparator 16 compares it with the command value and outputs a detected voltage Vb"!z that is higher than the command value. Figures (A) and (B) in Fig. 5 show examples of the output voltage. That is, (A) When the detected voltage Vb shown in FIG.
b' is output. Since this voltage V b' appears intermittently and has different magnitudes and widths, the waveform shaping circuit lI? 5] Shape the waveforms so that they have the same size in step 7.

FIG. 5(C) shows an example of the output voltage Vα, and when the waveform of (B) is input, the waveform shaping circuit 17 increases the width without changing it and makes the heights equal. To,
Shape the waveform. Furthermore, the output Vα of the waveform shaping circuit 17 is converted into a DC voltage vf by an f/v converter 18, as shown in FIG.

Therefore, the current IP of the auxiliary winding 5A is
3, the DC voltage f of the f/V converter 18 is supplied according to f.

FIG. 6 shows an example of the results of rectification compensation using this method. When the rotation speed N2 is constant and the armature current IM is changed at point A, the auxiliary winding current iP is the armature current I
Since it follows the change in y and the input to the power amplifier is approximately direct current Ichikawa, the pulsation is small.

FIG. 7 shows another embodiment. That is, the average value circuit 19
is the output voltage Vf of the f/v converter 18 which is slightly flI#l
'fK: Averaging 1-1 Its output voltage Vfmi is input to the power amplifier 13. From this, the current of the auxiliary winding 5A is 1
P is i′iii when the input of the power amplifier 13 is almost perfect;
Since the current voltage becomes Vfm, there is almost no current pulsation.

According to this embodiment, since the current pulsation in the auxiliary winding is small,
A DC machine with good rectification performance is obtained in which the commutating magnetic flux does not lag behind the armature current in time.

Further, the smoothing reactor can be removed, and the size of the rectification compensator can be reduced.

〔Effect of the invention〕

According to the present invention, it is possible to provide a rectification compensator for a DC machine in which current pulsations in the auxiliary winding are reduced, pulsations in the interpolation magnetic flux are reduced, and good rectification performance can be obtained.

Since a twisted and smoothing reactor can be removed, a compact rectification compensator can be provided.

[Brief explanation of the drawing]

Fig. 1 is an exploded view of the stator and rotor of a DC machine, Fig. 2 is a circuit block diagram of a conventional rectification compensator, Fig. 3 is a diagram of conventional operating characteristics, and Fig. 4 is a rectification compensator of the present invention. 5 is a schematic diagram of the operation of the circuit, FIG. 6 is a diagram showing the operating characteristics of the present invention, and FIG. 7 is a circuit block diagram of another embodiment of the present invention. 5A... Auxiliary winding, 10... Brush, 11... Commutator, 12... Detection brush, 18... f/■ converter, 19... Rod 2 figure'JJ3 factor 4 Eye 15 Rod S diagram (4) 4 (2) Rod 7 diagram - m /! ;' Poetry series 17 Vto V,・O'' 2 Monkeyaku 3 f 3 // ,,, ? Otsu=CVf Kameichi--Two Arms" Ushi--H\1

Claims (1)

[Scope of Claims] 1. A rotor consisting of an armature and a commutator, and a stator consisting of a main pole, a commutator pole, and brushes. In addition to the commutator winding that passes the armature current to the commutator, an auxiliary winding that carries a full wave of current other than the Isogo current is provided near the exit of the brush. A detection brush is provided for detecting the voltage between the brush and the commutator piece, the voltage detected by this detection brush is compared with a command value, and the detected voltage that is equal to or higher than the command value is inputted to an 'ef/V converter. f
1. A DC machine and ρ rectification compensator, characterized in that it is provided with means for controlling the amount of current in an auxiliary winding in proportion to the output of a /V converter. 2. Claim 1, characterized in that means is provided for waveform-shaping the detected voltage equal to or higher than the command value using a waveform-shaping circuit, and inputting the output of the waveform-shaping circuit to the r/V converter. Rectification compensation device for DC machines. 3. In claim 2, the output of the f/V converter is averaged by an average value circuit, and the amount of current in the auxiliary winding is controlled in proportion to the output of the average value circuit. A rectification compensator for a DC machine characterized by the following.