JPS59194653A - Rectification compensator of dc electric machine - Google Patents

Abstract

PURPOSE:To improve the performance of a commutator by detecting a voltage between the segments of the commutator, and controlling the current of an auxiliary winding in response to the peak value of the detected voltage, thereby reducing the current pulsation of the auxiliary winding. CONSTITUTION:A voltage between the segments of a brush commutator near the outlet of the brush is detected by a detecting brush 15. The voltage detected by the brush 15 is inputted through an insulating amplifier 18 for insulating from a main circuit of a DC electric machine to a peak value holding circuit 19. The output of the holding circuit 19 is inputted to a power amplifier 16. Accordingly, the current of an auxiliary winding 9 is controlled by the amplifier 16 to the value in response to the peak value of the detected voltage by the brush 15, and supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rectification compensation device for a DC machine, and more particularly to a current control device for an auxiliary winding wound around a commutating pole iron core.

[Background of the invention]

In a DC machine, the position of the spark-free zone changes depending on the rotational speed and the state of film formation on the commutator surface, so it is difficult to achieve spark-free commutation over the entire operating range. As a countermeasure to this problem, 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.

FIG. 1 is a diagram showing the main parts of a conventional DC machine. In this figure, 1 is an annular yoke, 2 and 3 are the main pole and counter pole formed on the inner circumferential side, and 4.5.6 is the main pole iron core that constitutes the main pole 2, and the main pole winding. Lines and compensation windings 7.8.9 are a commutator core, a commutator winding, and an auxiliary winding that constitute the commutator 3; 10 is a rotating armature; 11. ．． 12 is ti constituting the armature 10
These are the child core and armature winding. The main pole 2 is the rotating armature 10
At the same time, the compensation winding 6 compensates for bias in the main magnetic flux due to armature reaction, and the commutator 3
This provides the commutating magnetic flux for generating rectified electromotive force to the rectifying coil. Further, the auxiliary winding 9 wound around the tip of the commutating pole iron core 7 is wound differentially with respect to the commuting pole winding 8, and the commutating magnetomotive force is adjusted by controlling the current of the auxiliary winding 9. do the work.

FIG. 2 is an electrical circuit diagram of a rectifier tI@ compensation device that controls the current flowing to the auxiliary winding according to the rectification state. In this figure, 13 is a brush, 14 is a commutator, 15 is a detection brush,
16 is a power amplifier, and 17 is a smoothing reactor. Note that the other symbols are the same as in FIG. 1. The armature current IM flows through one brush 13 and the commutator 14 to the magnet winding 12 (not shown in FIG. 2), and then through the commutator 14 and the other brush 13 to the compensation winding 6. and flows through the commutator winding 8. On the other hand, the detection brush 15 detects the brushy commutator strip voltage near the brush outlet, which indicates whether the rectification compensation is good or bad.
It is controlled and supplied by the 1@ unit 16 to a value corresponding to this detected 1 pressure vbK. In other words, in this method, if the detection voltage is within ±3V, sparks will not be generated from the brush.
The interpolation magnetomotive force is adjusted by controlling the value of the current i in the auxiliary winding 'crK*according to the detection voltage b, and the detection voltage Vb is always kept within ±3V in an attempt to achieve sparkless rectification. It is something.

According to this rectification compensation method, the interpolation magnetomotive force can be adjusted according to the rectification state, that is, the detected voltage vb, but on the other hand, there is a problem in that the DC 1p flowing through the auxiliary winding 9 has large pulsations.

, Figures 3 (a) to (b) are operational characteristic diagrams of this rectification compensation system. When the rotation speed N of the DC machine is kept constant as shown in Fig. 3 (a), and the armature current is changed by 1.-1 at a time point of 1 A as shown in Fig. 3 (ri), the auxiliary winding 9 Current i.

Although it follows the change in armature current IM(7) as shown in Fig. 3-9, the pulsation is large. The reason for this is that the rectifying performance of each rectifying coil of the armature winding 12 is different from each other, so if the detected voltage % is large for each commutator piece, the commutator magnetic flux will pulsate, Due to the eddy currents occurring in the path, the compensating magnetic flux is delayed in time with respect to changes in the armature current, which actually deteriorates the rectifying performance. Also, this current i
If a smoothing reactor 17 is inserted as shown in FIG. 2 in order to suppress the pulsation of the rectification compensator, a disadvantage arises in that the size of the rectification compensator becomes large.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a DC rectification compensator that is compact and provides good rectification performance.

[Summary of the invention]

In order to achieve this object, the present invention focuses on the fact that sparks from the brush are generated in response to the peak value of the detection voltage vb, and provides a circuit for bolding the peak value of the detection voltage vb.
The present invention is characterized in that current pulsations in the auxiliary winding are reduced by controlling the current in the auxiliary winding according to the peak value of the held detection voltage vb.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail based on FIGS. 4 to 7.

4i1tA) - (This is an explanatory diagram showing the detection status/pus of the voltage between the brush commutator pieces by the gummy detection brush and the result. In FIG. 4(A), 12a is the rectifier coil of the armature winding 12; 13 is a main plane, 14 is a commutator, 14a,
14b is its commutator piece, and 15 is a detection brush. Now, assuming that the direction of rotation of the DC machine is the direction of arrow X, the detection brush 15 disposed at the outlet end of the main brush 13 detects the voltage vb at the end of commutation when the main brush 13 leaves the commutator piece 14a.
The detection results are shown in Figure 4 (Naka).
become that way. That is, the voltage Vb detected by the detection brush 151C is a voltage detected for each commutator piece, and varies as shown in the figure because the rectifying performance of each rectifying coil is different.

Further, FIG. 4(c) shows the generation state of brush sparks detected by a phototube or the like (not shown), and the brush sparks are detected when the detection voltage Vb is the spark generation limit voltage v5. This occurs when the detection voltage vb is exceeded, and is influenced by the peak value of the detection voltage vb.

As mentioned above, the present invention has been made with attention to this point, and FIG. 5 is an electrical circuit diagram of a rectification compensation device according to an embodiment thereof. This embodiment differs from the conventional example shown in FIG. 2 in that an isolation amplifier 18 and a peak/direct hold circuit 19' are newly added. In addition, the F-beak 1 direct hold circuit 19 includes a capacitor Cf, a return resistance field, and diodes D, D.

It consists of

In such a circuit configuration, the armature current flows along the same path as in the conventional case. -The voltage Vb detected by the detection brush 15 is input to the peak value hold circuit 19 via the absolute +J amplifier 18 for insulating it from the main circuit on the left. V
, is held, and is discharged by the return resistor. In other words, the peak value hold circuit 19 is
When the detection voltage vb shown in (a) is input, its peak voltage Vb is summed up and input to the DC power amplifier 16 with little pulsation as shown in Fig. 6 (b). Ru. The output voltage of the auxiliary winding 9 is determined directly by the power amplifier 16 according to the peak value of the detected voltage vb.
blj controlled and supplied.

FIGS. 7(A) to 7(C) are four diagrams showing the operation of the rectification compensator of this embodiment. With the rotational speed N of the DC current I constant as shown in Figure 7 (a), the armature current ■ is varied at time tA as shown in Figure 7 (b), and the As shown in FIG. 7(c), when the current in the auxiliary winding 9 reaches 1°, as shown in FIG. Since the voltage has an almost DC waveform (・),
The pulsation becomes extremely small. Therefore, it is possible to prevent the generation of current in the commutator magnetic path due to pulsations in the commutator magnetic flux, eliminate the delay of the interpole magnetic flux with respect to changes in the armature current, and perform a good rectifying action.

FIG. 8 is an electrical circuit diagram of a rectification compensator according to an embodiment of the present invention (an average value circuit 20 is further added to the embodiment of FIG. 5). That is, the fluctuating peak value V, which is the output of the peak value hold circuit 19, as shown in FIG. Therefore, the input to the power amplifier 160 becomes a direct current voltage with almost no pulsation, and a better rectification effect than in the embodiment shown in FIG. 5 can be achieved. can.

〔Effect of the invention〕

As explained above, according to the present invention, the voltage between the brush commutator pieces near the brush outlet is detected, the peak value of this detected voltage is held, and the current of the auxiliary winding is determined according to the held peak value. By controlling , the d current pulsations in the auxiliary winding are reduced, thereby preventing the generation of eddy currents in the auxiliary and magnetic paths due to pulsations in the interpole magnetic flux, and reducing the delay in the interpole magnetic flux relative to armature current changes. Without this, a good rectification effect can be achieved. Moreover, since there is no need to use a smooth reactor as in the conventional case, it is possible to downsize the mounting device.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the main parts of a DC machine, Figure 2 is an electrical circuit diagram of a conventional rectification compensator, Figures 3 (a) to e→ are its operating characteristics, and Figures 4 (a) to (h). ) is an explanatory diagram showing the detection state and result of the voltage between plano and commutator pieces, FIG. b) Country of explanation of the operation of the peak value hold circuit;
FIGS. 7A to 7C are operating characteristic diagrams thereof, and FIG. 8 is a circuit diagram of a rectification compensator according to another embodiment of the present invention. l...Yoke, 2...Main pole, 3...
...Auxiliary pole core, 4...Main pole core, 5...Main pole winding, 7...Commuting pole core, 8...Urakoshi winding , 9...Auxiliary winding, 13...Main brush, 14...Commutator, 15...Detection brush, 16...' 1-E force amplifier, 18...
-...Isolation amplifier, 19...Peak direct hold circuit, 2o...Average value circuit Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5/Q Fig. 6 Figure 7

Claims (1)

[Claims] 1. A fixing having a main pole consisting of a main pole iron core and a main pole winding, a commutating pole consisting of a commutating pole iron core and a commutating pole winding, and a brush on the inner peripheral side of an annular yoke. In the electric motor, an auxiliary winding is provided on the commutator core, means for detecting voltage between the brush commutator pieces near the outlet of the brush, and a peak value of the voltage detected by the detecting means. 1. A rectification compensation device for a DC machine, comprising: a holding circuit, and controlling one current of the auxiliary winding according to the peak value. 2. The rectification compensator for a DC machine according to claim 1, wherein the peak value hold circuit includes a peak value holding capacitor and a return resistor connected in parallel. 3. Claim 1 is characterized in that a circuit for determining an average value of the output of the peak value hold circuit is provided, and the current of the auxiliary winding is controlled according to this average value. Rectification compensation device for DC machines.