JPS59175366A - Rectification compensator of dc electric machine - Google Patents

Abstract

PURPOSE:To prevent the generation of sparks at the outlet and inlet sides of a brush by winding the first and second windings for regulating the size and distributed shape of an interpole magnetic flux on a pole core, and controlling the magnetomotive forces of the windings. CONSTITUTION:A stator has a main pole including a main pole core and a main pole winding 5, an interpole including an interpole core and an interpole winding 7, and a brush 11. A rotor has an armature and a commutator 12. The first winding 19A which regulates the magnitude of the interpole magnetic flux and the second winding 19B which regulates the distributed shape of the interpole magnetic flux are provided on the interpole core, and the magnetomotive forces are individually controlled by current controllers 18A, 18B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rectification compensator for a DC machine, and particularly to one that adjusts the magnetic flux of a commutator.

[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 equipment. On the other hand, DC machines have a phenomenon in which the 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, rectification compensation systems shown in FIGS. 1 to 3 have been proposed.

FIG. 1 is an exploded view of the main parts of a conventional DC machine. In the figure, 1 is an annular yoke, 2.3 is a main pole and a counter pole formed on the inner circumferential side thereof, and 4 and 5 are a main pole iron core and a main pole winding that constitute main pole 2. , 6, 7.8 are a commutator core, a commutator winding, and an auxiliary winding that constitute the commutator 3, 9 is a rotating armature, and 10 is the armature winding. The main pole 2 provides a main magnetic flux to the armature winding 10, and the commutative pole 3 provides a commutative magnetic flux for generating a rectified electromotive force when the current flowing in the armature winding 10 is reversed. Further, a t provided at the tip of the commutating pole iron core 6 is provided.
'The Lfc auxiliary winding 8 is wound differentially with the commutator winding 7, and as shown in FIG. Since the interpolation magnetic flux becomes excessive, the magnetomotive force is adjusted to move the load shaft onto the O-P line at the center of the non-sparking zone.

Figure 3 is a block circuit diagram of a device that controls the amount of current in the auxiliary winding according to the rotational speed and armature current to compensate for the no-spark zone movement phenomenon. The same reference numerals as in Figure 1 are given. Other codes are as follows.

11 is a brush, 12 is a commutator, 13 is a current detector, 14
15 is a rotation speed detector, 15 is a multiplier, 16 is a gate signal generator, 17 is an external DC power supply, and 18 is a current control circuit consisting of semiconductor switching elements such as a thyristor, a GTO thyristor, and a power transistor.

That is, this device controls the current tpk supplied to the auxiliary winding 8 from the external DC power supply 17 as follows while passing the commutator winding 7Kt mechanized current IM. and the output of the rotation speed detector 14 are input to the multiplier 15, and the result is input to the gate signal generator 16, and the gate signal obtained thereby controls the switching frequency, conduction rate, etc. of the current control circuit. , to control the current flowing through the auxiliary winding 8. As a result, the current 1 in the auxiliary winding 8 changes depending on the rotational speed and armature current, so the interpolation magnetomotive force changes, and the load axis is shifted to the center of the non-sparking zone as shown in Figure 2. Move onto the O-P line. As a result, the DC machine can be operated with sparkless rectification.

However, in the conventional device as described above, when the amount of movement of the non-sparking zone is large, it is necessary to increase the magnetomotive force sound that can be controlled by the auxiliary winding 8, and this can be done by increasing the current or the number of turns of the auxiliary winding. However, if the current is increased, it is necessary to use a switching element with a large capacity in the current control circuit 18, and if the number of turns is increased, it is necessary to use a switching element with a high withstand voltage. It has the disadvantage of high cost. In addition, the magnetic flux distribution near the commutating pole is not necessarily symmetrical between the commutation start side and the commutation end side, and despite this, conventionally the commutating pole magnetomotive force is determined by focusing on the brush exit side, that is, the commutation end side. Even if there is no spark on the brush outlet side, sparks may be generated on the brush inlet side, and it is difficult to eliminate this with conventional equipment.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rectification compensator for a DC machine that overcomes the drawbacks of the prior art described above, can be implemented at a relatively low cost, and can prevent sparks from occurring on the outlet and inlet sides of the brush.

[Summary of the invention]

In order to achieve the above object, the present invention provides a stator 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 brushes, an armature and a commutator. and a rotor that transmits and receives power to the armature via the brush and the commutator, wherein the commutator core includes a first winding that adjusts the magnitude of the commutator magnetic flux; A second winding for adjusting the distribution shape of the polar magnetic flux is provided, and a control means for controlling the magnetomotive force of the first and second windings is further provided.

In addition, in response to movement of the non-spark zone position due to changes in the state of film formation on the brush, etc., the rectification state is detected and at least one of the first and second windings is adjusted according to the detected value. It is designed to adjust the magnetomotive force of the wire.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 4 to 7.

FIG. 4 is a developed view showing an example of the configuration of a DC machine according to the present invention. In this figure, parts corresponding to those in FIG. 1 are given the same reference numerals as in FIG. Magnetic flux φ due to line 7
, the magnetic flux φ11. This is because the first winding 19A and the second winding 19B which generate φ,2 are provided.

That is, the first winding 19A is wound around the root of the commutator core 6 differentially with respect to the commutator winding 7, and the magnetic flux φpt K
This allows the magnetic flux φ caused by the commutator winding 7 to be reduced and the amount of magnetic flux passing through the entire commutator core 6 to be adjusted. Also, the second
The winding 19B is formed by dividing the tip of the commutator core 6 into two by the slot 20 into a rectification start side and a rectification end side, and winding the commutator winding 7 on one side differentially. The magnetic flux φ, 2 reduces the magnetic flux φ caused by the commutator winding 7, and the amount of magnetic flux passing through one side of the commutator core 60 is adjusted so that the magnetic flux distribution shape under the commutator can be adjusted. Since the rotation direction of the armature 9 is in the direction indicated by the arrow, the second winding 19B is connected to the commutating pole iron core 6.
It is provided on the rectification start side of the tip.

Figure 5 shows the shape of the magnetic flux distribution under the commutating pole, where the magnetic flux distribution φ under the commuting pole. Since the main magnetic flux φM leaks to the bottom of the commutator, the main magnetic flux φM and the commutator magnetic flux φ are combined and are not symmetrical with respect to point P at the center of the commutator.

As a result, the rectified magnetic flux becomes excessive on the rectification start side A in the rectification section, and on the contrary, the rectified magnetic flux becomes insufficient on the rectification end side B. Therefore, the commutating magnetic flux is normally rectified at the end side BK.
If you pay attention to this and decide, there will be over-rectification on the rectification start side A,
Sparks are generated on the brush inlet side, which is unfavorable for rectification. The second winding 19B mentioned above is for preventing this,
It has the function of completely reducing the magnetic flux φ due to the commutating pole winding 7, and reducing the magnetic flux on the commutation start side A to prevent commutation sparks from occurring from the inlet side of the brush.

FIG. 6 is a block circuit diagram showing a rectification compensator for a DC machine according to an embodiment of the present invention, which adjusts the magnetomotive force of the first and second windings described above. In this figure, parts corresponding to those in FIG. 4 are designated by the same reference numerals as in FIG. 4. Also,
The configurations of the current detector 13, rotation speed detector 14, multiplier 15, and external DC power supply 17 are the same as in the case of FIG. 3.

In this embodiment, since the commutating pole has a first winding 19A and a second winding 19Bt which are wound differentially with respect to the commutating pole winding 7, in order to control each of them individually, Two current control circuits 18A, 18B are provided, and correspondingly two gate signal generators 16A are provided.

It is located in 16B'. In addition, 21 is a voltage amplifier that functionally amplifies the output of the multiplier 15, 22 is a detection brush provided near the outlet side of the brush 11, 23 is an isolation amplifier that isolates the main circuit and control circuit of the DC machine, and 24 is a voltage amplifier.

In this configuration, the current l, 2 of the second winding 19B connected to the interpolation is obtained by multiplying the detected values by the current detector 13 and the rotation speed detector 14 by the multiplier 15, and the output thereof is calculated as in the conventional case. The signal amplified by the voltage amplifier 21 is controlled by the multi-gate signal generator 16B1 and the current control circuit 18Bt for adjustment.

Leakage of the main magnetic flux to the bottom of the interpole can be determined based on the operating state, that is, the magnitude of the armature current and rotational speed. It is designed to be controlled by

In addition, the current 1.1 of the first winding 19A provided in the commutating pole is
The voltage Vb detected on the brush outlet side by the detection brush 22 is inputted to the voltage amplifier 24 via the insulation amplifier 23, where it is compared with the command value S (for example, ±3V of the spark generation limit voltage), and the difference is calculated as a function of the voltage. The amplified output is input to the gate signal generator 16A, and the current control circuit 18A is controlled and adjusted by the gate signal obtained from the signal generator 16A. As a result, the magnetomotive force of the first winding 19A is controlled so that the detection voltage of the detection brush 22 provided on the brush outlet side is within ±3V of the spark generation limit voltage, so that the magnetomotive force of the first winding 19A is Regarding the rectification spark on the large rectification side, as described above, the magnetomotive force of the second winding 19B is adjusted according to the armature current and rotation speed so that the rectification magnetic flux on the rectification start side does not become excessive. This can also be prevented.

As described above, according to this embodiment, it is possible to suppress the generation of sparks on the outlet side and the inlet side of the brush, and it is possible to always operate with sparkless rectification. Furthermore, according to this embodiment, two windings are provided which are differentially wound with the interpolation winding, and the magnetomotive force of each winding can be adjusted individually. The magnetomotive force of the conventional single auxiliary winding is much smaller than that of a single auxiliary winding, and assuming that the movement of the non-sparking band is the same, the capacitance and voltage resistance of the switching element in the current control circuit will be much smaller than that of the conventional single auxiliary winding. Therefore, even if the number of switching elements is doubled, cheaper switching elements can be used in terms of capacity and breakdown voltage, and the cost of the rectification compensator can be reduced.

In the above embodiment, the magnetomotive force of the first winding was controlled according to the rectification state on the brush outlet side, and the magnetomotive force of the second winding was controlled according to the armature current and the rotation speed. The magnetomotive force of the second winding may be controlled depending on the magnetomotive force of the main pole winding, that is, the magnitude of the current flowing through the main pole winding.

By the way, although it varies depending on the brush material, rectifying sparks usually occur when the brush voltage exceeds the spark generation limit voltage of ±3V. Therefore, as shown in Fig. 7, the brush 1
Detection brushes 22A are installed near the outlet and inlet sides of 1.
, 22B are provided, and the voltage V between the brush 11 and the commutator 12 is
bz, Vbz f is detected, and this detected voltage Vb1. ■
By determining whether b2 exceeds the spark generation limit voltage by ±3vt, the rectification state of the DC machine can be detected. Therefore,
The first and second windings 19A provided on the commutating pole as shown in FIG.
.

The detection brush 22A is provided with a magnetomotive force of 19B near the outlet and inlet sides of the brush 11 as described above.

By controlling according to the detected voltages Vb and Vb2 by 22BK, it is possible to prevent sparks from occurring on the outlet and inlet sides of the brush. Specifically, for example, the first volume 119
A detection brush 22 with a magnetomotive force t near the brush outlet side pressure
Trap control may be performed so that the voltage detected by AK is within ±3V, and the magnetomotive force of the second winding 19B is controlled so that the voltage detected by the detection brush 22B provided near the brush inlet side is within 3V. .

〔Effect of the invention〕

As explained above, according to the present invention, the first winding for adjusting the magnitude of the commutating magnetic flux and the second winding for adjusting the distribution shape of the commutating magnetic flux are wound around the commutating iron core. However, since these magnetomotive forces are fully controlled, the generation of sparks on the outlet and inlet sides of the brush can be effectively prevented.
! , even if the movement of the non-sparking band is large, the winding for interpolation magnetic flux control is divided into two parts, so the capacity and withstand voltage of the current control switching element are smaller than before, resulting in inexpensive rectification compensation. There is an advantage that the device can be configured.

[Brief explanation of the drawing]

Figure 1 is an exploded view of the main parts of a conventional DC machine, Figure 2 is a graph showing the movement of the spark-free zone with respect to rotational speed, Figure 3 is a block circuit diagram of a conventional rectification compensator, and Figure 4 is the main part of this machine. FIG. 5 is a developed view of essential parts showing an example of a DC machine according to the invention, and FIG. 5 is a developed view showing a gravitational state showing magnetic flux distribution near a commutating pole. 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 , 9... Armature, 11... Brush, 12... Commutator, 13... Current detector, 14... Rotation speed Detector, 15...
Multiplier, 16A, 16B...Gate signal generation circuit, 17...DC power supply, 18A, 18B...
...Current control circuit, 19A...First winding,
19B...second winding, 20...slot, 22, 22A, 22B...detection brush. # l Cause $3 Figure 4 Figure $5 Figure

Claims (1)

[Scope of 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 a ring-shaped yoke. and a rotor having an armature and a commutator, and power is transferred to and from the armature via the brush and the commutator, wherein the commutator core has a magnitude of the commutator magnetic flux. A first winding for adjusting and a second winding for adjusting the distribution shape of the interpolation magnetic flux are provided, and a control means for controlling the magnetomotive force of these first and second windings is further provided. Features a DC machine rectification compensation device. 2. Claim 1, characterized in that the first winding is disposed on the root side of the commutator core, and the second winding is disposed on the tip side of the commutator core. Rectification compensation device for DC machines. 3. Permissible Claims In claim 1 or 2, the tip of the commutator core is divided into two by a slot into a rectification start side and a rectification end side, and the second winding is A rectification compensator for a DC machine, characterized in that the device is wound on the rectification start side. 4. In claim 1, 2, or 3, the control means includes a magnetomotive force tube of at least one of the first and second windings, the commutator, and the brush. 1. A rectification compensation device for a DC machine, characterized in that the device performs control according to a rectification state between the two. 5. Claims 1, 2, or 3, wherein the control means controls the magnetomotive force of the first winding according to a commutation state between the commutator and the brush, and A rectification compensation device for a DC machine, characterized in that the magnetomotive force of the second winding is controlled according to armature current and rotation speed. 6. Claims 1, 2, or 3, wherein the control means controls the magnetomotive force of the first winding according to a commutation state between the commutator and the brush, and A rectification compensation device for a DC machine, characterized in that the magnetomotive force of the second winding is controlled according to the magnitude of the magnetomotive force of the main pole winding. 7.% Allowance In claim 1 or 2, the control means detects the magnetomotive force of the first and second windings by a detection brush provided near the outlet side and near the inlet side of the brush. 1. A rectification compensator for a DC machine, characterized in that it is controlled in accordance with a detected voltage. 8. In claim 7, the control means:
The magnetomotive force of the first winding is controlled according to the voltage detected by a detection brush provided near the outlet side of the brush, and the magnetomotive force of the second winding is controlled near the inlet side of the brush. A rectification compensator for a DC machine, characterized in that it is controlled according to the voltage detected by a brush○