JPS61207189A - Rectification compensator of dc machine - Google Patents

Abstract

PURPOSE:To always compensate a rectification by correcting a current flowed to an auxiliary winding in response to excess or insufficient value of a rectification compensating amount and the magnitude of the value. CONSTITUTION:The outputs of a current detector 13 and a rotating speed detector 14 are input to a multiplier 15, and the result is input to a gate signal generator 16. The switching frequency and the conduction rate of a current controller are controlled by the obtained gate signal to control a current flowed to an auxiliary winding 8. The position of a sparkless zone varies as the operating time is elapsed, and when exceeding a rectification compensating range, a spark is generated from a brush 11. The excess or insufficient value of the rectification compensating amount and the magnitude of the amount are detected by a search coil 19, and a rectification compensating amount correcting circuit 20 outputs a correcting voltage in response to the output of the coil 19. Thus, the optimum rectification compensation can be always performed.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a rectification compensator for a DC machine such as a motor or a generator equipped with a commutator and brushes, and particularly relates to a rectification compensator for a DC machine such as a motor or a generator equipped with a commutator and brushes, and particularly relates to a rectification compensation device for a DC machine such as a motor or a generator equipped with a commutator and brushes. Concerning what you have.

[Background of the invention]

It is no exaggeration to say that the rectification performance of a DC machine affects the performance and life of the machine, and a lot of research has been done in the past. The quality of this rectification performance is determined by measuring the no-spark zone of the actual machine. On the other hand, in a DC machine, there is a phenomenon in which a non-sparking band moves depending on the rotational speed, and if the amount of movement of this non-sparking band is large, it becomes impossible to operate with non-sparking commutation.

As a countermeasure against this problem, a rectification compensation system shown in FIGS. 6 to 8 has been proposed (see Japanese Utility Model Application No. 50-99408).

FIG. 6 is an exploded view of the main parts of a direct current machine equipped with a conventional rectification compensator. In the figure, 1 is a ring-shaped yoke, 2, 3
4 and 5 are the main pole iron core and the main pole winding that constitute the main pole 2, and 6, 7.8 are the commutator core that constitutes the commutator pole 3, A commutator winding, an auxiliary winding, and a rotating armature.

10 is its armature winding. Main pole 2 is armature winding 10
The commutator 3 provides a commutator magnetic flux for generating a rectified electromotive force when the current flowing in the armature winding 10 is reversed. Also.

The auxiliary winding 8 provided at the tip of the commutating pole iron core 6 is wound differentially with respect to the commuting pole winding 7, and as shown in FIG. Therefore, the magnetomotive force is adjusted to move the load shaft onto the 0-P line at the center of the sparkless zone.

Figure 8 shows the amount of current in the auxiliary winding depending on the rotation speed and armature current.
FIG. 6 is a block circuit diagram of a device for controlling the spark zone movement phenomenon and compensating for the no-spark band movement phenomenon, in which parts corresponding to FIG. 6 are given the same reference numerals as in FIG. 6. Other symbols are as follows. 11 is a brush, 12 is a commutator, 13 is a current detector, 1
4 is a rotation speed detector, 15 is a multiplier, 16 is a gate signal generator, 17 is an external DC power supply, 18 is a thyristor, G i
'0 This is a current-side circuit composed of semiconductor switching elements such as thyristors and power transistors.

That is, this device controls the current iC supplied from the external DC power supply 17 to the auxiliary winding 8 by K as follows, while passing the armature current IM through the commutator winding 7.

That is, the outputs of the current detector 13 and the rotational speed detector 14 are input to the multiplier 15, and the results are used to control the gate signal conduction rate, etc., and the current flowing through the auxiliary winding 8. As a result, the current IC in the auxiliary winding 8 changes according to the rotational speed and the armature current, so the interpolation magnetomotive force changes, and the load axis is shifted to the center of the non-spark zone as shown in FIG. -Move onto the P line. As a result, the DC machine can be operated with sparkless rectification.

However, as the operating time of the DC machine passes, the oxide film formed on the brush sliding surface of the commutator gradually becomes thicker.
It was found that as the contact resistance between the commutator and the brushes gradually increases, the short-circuit current flowing through the rectifier coil decreases, causing a change in the position of the non-sparking zone of the DC machine.

If there is a large change in the position of the spark-free zone due to this oxide film, sparks will be generated from the brush, so the amount of current IC flowing through the auxiliary winding 8 must be adjusted each time using the rectification compensator described above. The problem is that it doesn't.

[Purpose of the invention]

An object of the present invention is to provide a rectification compensation device for a DC machine that can always perform good rectification compensation even if the position of the non-sparking zone changes with the passage of operating time.

[Summary of the invention]

In order to achieve this object, the present invention provides a rectification state detection means 1 for detecting the excess or deficiency of the amount of rectification compensation and its magnitude; A rectification compensation amount correction means for correcting the current flowing through the auxiliary winding is provided, and if the position of the non-sparking zone changes with the passage of operating time and sparks are generated from the brush, the rectification compensation amount is determined to be excessive or insufficient. The present invention is characterized in that the current flowing through the auxiliary winding is automatically corrected according to its magnitude.

[Embodiments of the invention]

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

FIG. 1 is a block circuit diagram of a rectification compensator according to an embodiment of the present invention. In the figure, parts corresponding to those in FIG. 8 are given the same reference numerals as in FIG. 8.

The difference between this embodiment and the conventional example shown in FIG. 8 is that the main pole iron core 4
A search coil 19 for detecting the rectification state is wound around the rectification compensation amount correction circuit 201 which inputs the output of the search coil 19 and generates a correction voltage, and the armature and commutator. An adder 21 is provided to add to the output.

Therefore, when no spark is generated in the brush 11, the current iC flows through the auxiliary winding 8 in the same way as in the conventional case.
Good rectification compensation is performed.

However, the position of the spark-free zone changes with the passage of operating time and exceeds the commutation compensation range 1, armature and commutator brush 1
Sparks are generated from 1. This generation of sparks is caused by an excess or deficiency in the amount of rectification compensation, but since the search coil 19 for rectification state detection is wound around the main pole iron core 4, the excess or deficiency of this amount of rectification compensation and its size are determined by the search coil 19. Detected by 19. In other words, the direction of the short-circuit current flowing through the rectifier coil changes depending on the amount of rectification compensation, and the magnitude of the short-circuit current changes depending on the amount of excess or deficiency, so the magnetic flux ψα created by this short-circuit current is the main 1 passing through pole core 4
, armature and commutator? - A voltage is generated in the coil 19 according to the magnitude of the rectification compensation amount, and is input to the rectification compensation amount correction circuit 20. In the rectification compensation amount correction circuit 20, if a spark is generated on the under-rectification side, a negative correction voltage is outputted, and this is added to the output of the multiplier 15 in the adder 21 to reduce this output. Therefore, tRi c flowing through the auxiliary winding 8 decreases, and the interpolation magnetomotive force becomes stronger. On the other hand, if the spark is generated on the exit side,
A positive correction voltage is output, and this is applied to the adder 21 and the multiplier 15.
is added to the output of , increasing this output. Therefore, the current i,2 flowing through the auxiliary winding 8 increases and the interpolation magnetomotive force becomes weaker. As a result, even if sparks are generated from the brush 11, the current i(2) flowing through the auxiliary winding 8 is immediately corrected in a direction that does not generate sparks, so that good rectification compensation can be performed.

Moreover, FIG. 2 is a block circuit diagram of a rectification compensator showing a more specific embodiment when the present invention is applied to a DC machine operated in four quadrants. In this figure, parts corresponding to FIGS. 1 and 8 are designated by the same reference numerals as those in these figures.

In FIG. 2, 22 is a function generator having five characteristics as shown in FIG. 83, 23 is an operation determination circuit, and 24 is a current direction determination circuit. 25 is a rectification state detector consisting of a proportional circuit, and 26 is a correction amount setting circuit consisting of a proportional circuit having characteristics as shown in FIG. 4. These constitute the rectification compensation amount correction circuit 20. 27A to 27D are analog switches, and Trl'' Tf4 is a power transistor, which is connected in an H type corresponding to four-quadrant operation, and the current control circuit 18 described above is configured.

Figure 5 shows the rotation speed during four-quadrant operation consisting of forward rotation, forward rotation regeneration, reverse rotation, and reverse rotation regeneration, armature IIc flow operation pattern 1, armature and commutator analog switches 27A to 27
The ON-OFF pattern of D is shown.

In the rectification compensator configured as shown in FIG.
When no spark is generated from the brush 11, current iC flows through the auxiliary winding 8 in the same manner as in the conventional case. That is, in the case of normal rotation in which the armature current I flows in the direction of the solid arrow, the current direction determination circuit 24 provides the DKON signal to the analog switches 2A and 2F on the path of one output terminal α.

On the other hand, the armature current and rotation speed of the DC machine detected by the current detector 13 and the rotation speed detector 14 are greater than or equal to a predetermined value.
Since a voltage is output from the armature and commutator operation determination circuit 23, the transistor Tfl in the current control circuit 18 is turned on. Also, the output vH of the multiplier 15 is
2, the function generator 22 outputs a voltage Vθ corresponding to the output V of the multiplier 15, as shown in FIG. Therefore, the ON-OFF state of the transistor Tr4 is controlled by the gate signal generator 16 according to the output Vθ, and the current ic of the auxiliary winding 8 flowing in the direction of the solid arrow according to the magnitude of the armature current and the rotational speed is It is supplied from a DC power supply 17. In the case of forward rotation regeneration in which only the direction of the armature current I is reversed, the analog switches 27B and 27C in the path of the other output terminal of the current direction determination circuit 24 are turned on, and the transistor Tf2*'rrs is operated. For,
The auxiliary winding 80 current IC in the opposite direction as shown by the dashed arrow
flows. In addition, in the case of reverse rotation, the operating state of normal rotation regeneration is maintained, and in the case of reverse rotation regeneration, the electric current RI flowing to the auxiliary winding 8 is
Since the direction and magnitude of c are controlled, good rectification compensation is achieved.

On the other hand, the position of the spark-free zone changes with the passage of operating time and exceeds the commutation compensation range (1).The armature and commutator As mentioned above, sparks are generated from the brush 11 due to excess or deficiency in the amount of commutation compensation. The search coil 19 detects the excess or deficiency of this rectification compensation amount and its magnitude. Since this detection output is input to the rectification state detector 25 of the rectification compensation amount correction circuit 20, a detection voltage ■I corresponding to the excess or deficiency of the rectification compensation amount and its magnitude is output from the rectification state detector 25. This is input to the correction amount setting circuit 26 of the rectification compensation amount correction circuit 20.

As shown in FIG. 4, the correction amount setting circuit 26 outputs a correction voltage Vδ set according to the detected voltage vI. Here, the spark-free zone becomes narrower in accordance with the magnitude of the rotation speed, and the correction amount changes even for the same spark magnitude, that is, the same detection voltage Vt (as the rotation speed increases, the same spark magnitude Therefore, a plurality of correction voltages val to VJs are set for the same detection voltage (I) in accordance with the magnitude of the rotational speed. Since the correction voltage Vδ outputted from the correction amount setting circuit 26 is matched with the output Vθ of the function generator 22 in the adder 21, if a spark is generated on the under-rectification side, the combined value will be small. If the copole magnetomotive force increases and sparks are generated on the retreating flow side, the composite value increases and the copole magnetomotive force decreases. As a result, even if a spark is generated from the brush 11, the current i immediately flows to the auxiliary winding 8.
(Since y is corrected in a direction that does not generate sparks, good rectification compensation can be performed.

In each of the above embodiments, a search coil is used as a rectification state detection means, but instead of this, a phototube method is used to detect the size of a spark, and detect the spark that appears between the field winding terminals or between the positive and negative brushes. Other detection means can also be used, such as a method of detecting excess or deficiency in the amount of rectification compensation using noise.

〔Effect of the invention〕

As explained above, according to the present invention, when a spark is generated from the brush, the current flowing through the auxiliary winding is automatically corrected according to the excess or deficiency of the rectification compensation amount and its magnitude. Even if the position of the no-spark zone changes with the passage of operating time, the rectification compensation amount is automatically corrected to an appropriate amount, and good rectification compensation can always be performed.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of a rectification compensation device according to an embodiment of the present invention. FIG. 2 is a block circuit diagram of a rectification compensation device according to another embodiment of the present invention. FIG. 4 is a characteristic diagram of a correction amount setting circuit, FIG. 5 is an explanatory diagram of the operation of the rectification compensator shown in FIG. 2, and FIG. 6 is an exploded view of the main parts of a conventional DC machine. FIG. 7 is a characteristic diagram showing a movement phenomenon of the spark-free zone with respect to the rotational speed, and FIG. 8 is a block circuit diagram of a conventional rectification compensator. 1...Yoke, 2...Main pole, 3...
...Commuting pole, 4...Main pole iron core, 5...Main pole winding, 6...Commuting pole iron core, 7...Commuting pole winding , 8... Auxiliary winding, 9... Armature, 11... Brush, 12... Commutator □
, 13... Current detector, 14... Rotation speed detector, 15... Multiplier, 16...
Gate signal generation circuit, 17... DC power supply, 18
... Current control circuit, 19 ... Search coil for rectification state detection, 20 ... Rectification compensation amount correction circuit. Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A rotor having an armature and a commutator, a main pole consisting of a main pole iron core and a main pole winding, a commutating pole iron core, a commutating pole winding, and this commutating pole winding are differentially connected. A commutative pole consisting of an auxiliary winding wound around the
and a stator having brushes, means for detecting armature current, and means for detecting the rotation speed of the rotor,
In a rectification compensation device for a DC machine that controls a current flowing through the auxiliary winding according to a detected armature current and rotation speed, a rectification state detection means for detecting excess or deficiency of the amount of rectification compensation and its magnitude. A rectification compensation device for a DC machine, comprising: and a rectification compensation amount correction means for correcting the current flowing through the auxiliary winding according to the detected excess or deficiency of the rectification compensation amount and its magnitude. 2. The rectification compensation device for a DC machine according to claim 1, wherein the rectification state detection means comprises a search coil wound around the main pole iron core. 3. In claim 1, the rectification compensation amount correction means includes a rectification state detector that generates a detection voltage in a direction and magnitude according to the detected excess or deficiency of the rectification compensation amount and its magnitude; A rectification compensation device for a DC machine, comprising a correction amount setting circuit that generates a correction voltage according to the detected voltage. 4. The rectification compensation device for a DC machine according to claim 3, wherein the correction amount setting circuit is configured to change the correction voltage in inverse proportion to the rotation speed of the rotor.