JPS6051346B2 - DC machine rectification compensation device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a rectification compensation device for a DC machine.

It is no exaggeration to say that the rectification performance of a DC machine affects the performance and life of the machine, and much research has been conducted in the past. Recently, with the development of computers, rectification performance is being understood quantitatively through detailed calculations, but the current situation is that the quality of rectification is ultimately determined by measuring the no-spark zone of the actual equipment. be. Conventional methods of commutation compensation include methods that compensate for the movement of the non-spark zone at rotational speed, and methods that optically detect sparks generated from brushes and reduce the rate of change in armature current to prevent extreme deterioration of commutation. Methods to suppress this have been proposed.

However, the former method only compensates for movement of the non-spark zone at rotational speed, but cannot compensate for the normal commutation state.

Furthermore, the latter method is intended to suppress deterioration of commutation during transient times due to delays in the interpole magnetic flux, etc. when the armature current changes, and has the drawback that deterioration of commutation during steady operation cannot be compensated for. An object of the present invention is to provide a rectification compensator capable of compensating for rectification during steady operation and transient operation and also for movement of the non-sparking zone, while eliminating the drawbacks of the prior art described above.

In order to achieve this object, the present invention provides a detection brush that is in sliding contact with the commutator near the brush, and detects the voltage between the brush and the commutator piece when the commutator piece separates from the brush.
It is detected as a voltage between the brush and the detection brush, and when this detection voltage becomes larger than a positive predetermined value, the rectifying magnetic flux is increased, and when it becomes smaller than a negative predetermined value, the rectifying magnetic flux is decreased. It is characterized by the following.

Hereinafter, the present invention will be explained in detail based on the drawings.

As shown in Figure 1, the rectification phenomenon of a DC machine occurs when a brush 3 slides on the surface of the commutator 2 in a rotor consisting of an armature winding 1 and a commutator 2. During the transition to FIG.
This is a phenomenon that inverts up to 1a.

When this current 1 changes, leakage magnetic flux is generated and the coil (thickness) receiving the rectification of the armature winding 1
A reactance voltage Er (=-L7ft, where L is the inductance of the coil) is generated at the line.

Normally, in order to cancel this reactance voltage, a commutating pole or a commutating pole and a compensation winding (not shown) are provided to generate a rectified magnetic flux, and a rectified voltage E . give. This rectified voltage E. When the relationship between Ec and reactance voltage Er is Ec>E, the rectification curve in Figure 2 changes as shown by curve a (over-rectification), and the brush between the brush and the commutator piece under this brush at this time changes as shown in curve a (over-rectification). Contact voltage drop■
The change in B is as shown by curve a in FIG. Then EO=E
When r, the rectification curve becomes like curve b in FIG. 2 (DC rectification), and the brush contact voltage drop becomes like curve b in FIG. 3. Further, when EO is less than Er, both the rectification curve and the brush contact voltage drop become curve c (under-rectification). Therefore, in over-rectification (curve a) and under-rectification (curve c), the brush contact voltage drop on the brush outlet side exceeds the spark generation limit voltage, for example, about ±3V, and exceeds +3V or -3V (for example, When the voltage reaches -4V), sparks are generated from the brush sliding surface.

Therefore, the rectifying performance can be improved by adjusting the rectifying magnetic flux so that the brush contact voltage drop 8 is within the spark generation limit voltage, for example, ±3 . Fourth
The figure is a schematic diagram in which a detection brush 4 is provided on the outlet side of the brush 3.

Here, the detection brush 4 is arranged with a slight distance δ from the brush 3, and its thickness is desirably about the width of the commutator piece. As a result, when the commutator piece that is in contact with the brush 3 moves in the rotation direction and comes under the detection brush 4, the detection brush 4 contacts the commutator piece as a stylus, so that the brush 3 and its commutator The voltage between the child piece and the child piece can be detected. Furthermore, at the moment when the commutator piece moves in the rotation direction and separates from the brush 3 (at the end of commutation), only that commutator piece is in contact with the detection brush 4, so the brush 3 and the detection brush 4 If we detect the voltage between
A pike-like voltage at the end of commutation when the commutator pieces separate from the brush 3 can be detected. That is, the spike-like (A, c) voltage at the brush outlet shown in FIG. 3 can be detected for each commutator piece. FIG. 5 shows an electrical circuit diagram of a rectification compensator according to an embodiment of the present invention.

In FIG. 5, 3 is a brush, 4 is a detection brush, 5 is an armature, 6 is a separately excited field winding, 7 is a compensation winding, 8 is a commutator winding, 9 is an auxiliary commutator winding, 10 11 is a comparator, 11 is a commutator magnetization command circuit, 12 is a commutator demagnetization command circuit, and 13 is an auxiliary commutator winding excitation/demagnetization device.

Note that the commutating pole winding 8 and the auxiliary commutating pole winding 9 are wound on the same core, that is, the commuting pole core. Now, separately excited field winding 6
After applying another magnetic voltage between terminals Y and Y of the DC machine main circuit, when applying main circuit voltage between terminals X and 2. The main circuit current is supplied to the armature 5 in the order of the brushes 3, and further flows through the compensation winding 7 and the commutator winding 8, causing the armature 5 to rotate in the direction of the arrow. At this time, brush 3
The contact voltage drop between the brush 3 and the commutator 2 is detected as the voltage between the brush 3 and the detection brush 4, and this detected voltage is input to the comparator 10. In the comparator 10, when the detected voltage is above a positive spark generation limit voltage, for example +3V, it is output to the commutator magnetization command circuit 11, and when the detection voltage is below a negative spark generation limit voltage, for example -3V, the commutator is demagnetized. Output to the magnetic command circuit 12. The output signals of the commutator magnetization and demagnetization command circuits 11 and 12 are input to the auxiliary commutator winding excitation/demagnetization device 13. For this reason, when the auxiliary commutator winding excitation/demagnetizer 13 receives the magnetization command, it passes current through the auxiliary commutator winding 9 so that the magnetomotive force is in the same direction as the commutator winding 8, and the demagnetization command is issued. In the case of , the commutator winding 8
A current is passed through the auxiliary commutator winding 9 so that the magnetomotive force is in the opposite direction. Therefore, if the rectified magnetic flux generated by the interpolation magnetomotive force is over- or under-rectified, it can be adjusted to linear rectification, and the reactance voltage Er and rectified voltage E.

The relationship can always be set to the optimal relationship Er=NEO.
Although it is desirable to provide one detection brush for each brush arranged at each position in the circumferential direction, one detection brush may be provided on the brush holding arm at a position where brush sparks are most likely to occur. Further, FIG. 6 shows another embodiment of the present invention.

In FIG. 6, the same reference numerals as in FIG. 5 indicate the same or equivalent components, and 14 represents a commutating pole and a compensation winding excitation/demagnetization device. That is, the auxiliary commutator winding 9 in FIG. 5 is omitted,
The output of the commutator and compensation winding excitation/demagnetizer 14 is directly applied to both ends of the series circuit of the compensation winding 7 and the commutator winding 8.

Therefore, the voltage between the brush 3 and the commutator piece is detected as the voltage between the brush 3 and the detection brush 4, and the detected voltage is input to the comparator 10, and when the detected voltage is, for example, +3V or more, An input signal enters the commutator magnetization command circuit 11,
The commutator magnetization command circuit 11 outputs a signal for exciting the commutator winding and the compensation winding 7 to the commutator and compensation winding excitation device 14, and the commutator and compensation winding excitation device A current is applied to excite the pole and compensation winding.

This excitation current increases the magnetic flux of the interpole and the compensation winding, increasing the rectifying electromotive force, and the voltage between the brush 3 and the commutator piece (detected voltage) at the brush outlet when commutation is completed.
can be reduced to 3■ or less. Conversely, if the detection voltage between the brush 3 and the detection brush 4 is -3■ or less (for example,
-4■ or -5V), the output signal from the comparator 10 is input to the commutator demagnetization command circuit 12, and its output is input to the commutator and compensation winding excitation/demagnetizer 14. Flow current in a direction that reduces the current in the commutating pole and compensation winding.

Therefore, the commutating magnetic flux and the magnetic flux due to the compensation winding decrease, and the rectifying electromotive force becomes smaller, so that the voltage (detected voltage) between the brush 3 and the commutator piece at the end of commutation at the brush outlet is -3■ or more (e.g. -2■, -1V). In this manner, the magnetomotive force of the commutating pole and the compensation winding can be adjusted based on the detected voltage between the brush 3 and the detection brush 4, and rectification can be maintained in a good state.

In this embodiment, the magnetomotive force of the commutator and the compensation winding is adjusted based on the detected voltage, but the output of the excitation/demagnetization device is adjusted only to the commutator winding 8 or only to the compensation winding 7. It is also possible to adjust the magnetomotive force of only one of these by applying it to the magnetomotive force. As explained above, according to the present invention, the limit voltage at which sparks are generated from the brush, for example, exceeds the range of approximately ±3 V and exceeds +3 V or -3 V.
When the voltage is below V (for example -4V), the rectifying magnetic flux is increased or decreased to adjust the voltage between the brush and commutator on the brush outlet side to within the spark generation limit voltage, thereby adjusting the load condition and rotation speed. It is possible to compensate for the non-spark seven-band movement phenomenon caused by the difference in the number of sparks, and it is possible to always maintain a good rectification state.

[Brief explanation of drawings]

Fig. 1 A to C are diagrams explaining the principle of rectification, Fig. 2 is a rectification curve diagram, Fig. 3 is a characteristic diagram showing brush contact voltage drop corresponding to the rectification curve, and Fig. 4 is a brush according to the present invention. A schematic diagram showing means for detecting a spike voltage between a brush and a commutator at the outlet, FIG. 5 is an electrical circuit diagram of a rectification compensator showing one embodiment of the present invention, and FIG. 6 is a diagram showing another embodiment of the present invention. FIG. 2 is an electrical circuit diagram of the rectification compensator shown in FIG. 2...Commutator, 3...Brush, 4...Detection brush, 7...Compensation winding, 8...Commuting pole winding, 9...Auxiliary commuting winding, 10... Comparator, 11...Commuting pole magnetization command circuit, 12...Commuting pole demagnetizing command circuit, 13...Auxiliary commutating pole winding excitation/demagnetization device, 14...Commuting pole and compensation winding excitation/demagnetization device Magnetic device.

Claims (1)

[Scope of Claims] 1. A rotor having an armature and a commutator, a winding that generates rectified magnetic flux consisting of at least one of a main pole, a commutator winding, and a compensation winding, and a stationary member having brushes. A detection brush is provided in the vicinity of the brush and makes sliding contact with the commutator, and a detection brush is provided in the vicinity of the brush, and the commutator pieces are detected from the brush. The voltage between the brush and the commutator piece when they are separated is configured to be detected as the voltage between the brush and the detection brush, and when the detected voltage becomes larger than a positive predetermined value, A current is passed through the winding that generates the rectified magnetic flux so that the rectified magnetic flux increases, and when the detected voltage becomes smaller than a negative predetermined value, the rectified magnetic flux decreases in the winding that generates the rectified magnetic flux. 1. A rectification compensator for a DC machine, characterized in that the device is configured to allow current to flow as if the current is caused to flow. 2. A rotor having an armature and a commutator, a winding that generates a rectified magnetic flux consisting of at least a commutator winding among a main pole, a commutator winding, and a compensation winding, and a stator having brushes, In the device in which power is transferred to and from the armature via the brush and the commutator, a detection brush that is in sliding contact with the commutator is provided near the brush,
The voltage between the brush and the commutator piece when the commutator piece separates from the brush is detected as the voltage between the brush and the detection brush, and
An auxiliary commutator winding is wound on the core around which the commutator winding is wound, and when the detected voltage becomes larger than a positive predetermined value, the auxiliary commutator winding is A current is passed to generate a magnetic flux in the same direction as the rectified magnetic flux generated in the auxiliary commutator winding, and when the detected voltage becomes smaller than a predetermined negative value, the rectified magnetic flux generated in the auxiliary commutator winding is A rectification compensator for a DC machine, characterized in that it is configured to flow a current so as to generate a magnetic flux in the opposite direction to the rectified magnetic flux.