JPH0552152B2 - - Google Patents

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, rectification compensation methods 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 a ring-shaped yoke, 2 and 3 are a main pole and a counter pole formed on the inner circumferential side thereof, 4 and 5 are a main pole iron core and a main pole winding that constitute the main pole 2, and 6 ,7,8
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 commutator pole 3 provides a commutator magnetic flux for generating a rectified electromotive force when the current flowing in the armature winding 10 is reversed. In addition, the auxiliary winding 8 provided at the tip of the commutating pole core 6 is wound differentially with respect to the commuting pole winding 7, and as shown in FIG. As the current increases, the rectification moves toward the over-rectifying side (the interpolation magnetic flux is excessive), so 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 the figure are given. Other symbols are as follows. 11 is a brush, 12
is a commutator, 13 is a current detector, 14 is a rotation speed detector, 15 is a multiplier, 16 is a gate signal generator, 1
7 is an external DC power supply, and 18 is a current control circuit composed of semiconductor switching elements such as a thyristor, a GTO thyristor, and a power transistor.

That is, in this device, the armature current I _M is applied to the commutator winding 7.
At the same time, the current i _c supplied from the external DC power supply 17 to the auxiliary winding 8 is controlled as follows.
That is, the outputs of the current detector 13 and rotation speed detector 14 are input to the multiplier 15, the result is input to the gate signal generator 16, and the gate signal obtained thereby controls the switching frequency and the current control circuit. The current flowing through the auxiliary winding 8 is controlled by controlling the conduction rate and the like. As a result, the current of the auxiliary winding 8
Since i _c changes depending on the rotational speed and armature current, the interpolation magnetomotive force changes, and the load axis moves onto the O-P line at the center of the non-sparking zone, as shown in FIG. As a result, the DC machine can be operated with sparkless rectification.

However, the conventional devices as described above are good when applied to DC machines with small load fluctuations, but
When applied to a DC machine where the load changes suddenly, there is a problem in that rectification is poor and sparks are generated from the brushes.

[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 not only during steady operation but also during sudden load changes.

[Summary of the invention]

The inventors of the present invention investigated the reason why good rectification compensation cannot be performed during load fluctuations as described above through various experiments and studies, and discovered that the reason is as follows.

In other words, in a DC machine, when the load suddenly changes, the interpole magnetic flux also changes accordingly, resulting in eddy currents occurring in the interpole magnetic path, and due to the influence of this eddy current, the interpole magnetic flux changes temporally relative to the armature current. There is a delay and the rectification tends to be insufficient. If the above-mentioned rectification compensation device is added to this and the current in the auxiliary winding is increased in proportion to the magnitude of the armature current, the commutating magnetic flux further decreases, resulting in insufficient rectification and poor commutation.

Further, when a current from an external DC power supply is controlled by turning on and off a semiconductor switching element and supplied to the auxiliary winding, a pulsating current is superimposed on the DC current in the current of the auxiliary winding. As a result, when the current in the auxiliary winding pulsates, a problem arises in that the no-spark zone of the DC machine becomes narrow. As a countermeasure for this,
The inventors' experiments have confirmed that it is sufficient to set the switching frequency of the semiconductor switching element higher than a certain value so that the commutating magnetic flux does not pulsate due to the pulsation of the current in the auxiliary winding. Ta.

On the other hand, since the switching frequency of the semiconductor switching element is affected by the inductance value of the auxiliary winding circuit, it becomes difficult to increase the frequency of the semiconductor switching element by inserting a reactor that increases the inductance in the auxiliary winding circuit. .

The present invention has been made in view of these points, and includes a first-order lag circuit between the armature current detection means and the multiplier, so that the current in the auxiliary winding is controlled temporally relative to changes in the armature current. It is characterized by the fact that it changes with a delay.

[Embodiments of the invention]

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

FIG. 4 is a block circuit diagram of a rectification compensator according to an embodiment of the present invention. In this figure, parts corresponding to those in FIG. 3 are given the same reference numerals as in FIG. 3.

This embodiment differs from the conventional example shown in FIG. 3 in that a first-order lag circuit 19 is newly provided between the current detector 13 and the multiplier 15. The first-order delay circuit 19 serves to temporally delay the output voltage with respect to the input voltage from the current detector 13 and input the delayed output voltage to the multiplier 15 .

Figure 5 shows the armature current _I
When suddenly changes from a light load to a heavy load at time t ₁ , the current in the auxiliary winding i _c , the magnetic flux φ _IP due to the interpolation winding, the magnetic flux φ _c due to the auxiliary winding, and the magnetic fluxes φ _IP , φ _c The changes in the total interpolation magnetic flux φ〓 _IP , which is the composite magnetic flux, are shown.

In the rectification compensation device shown in FIG. 4, as in the conventional example shown in _{FIG .} is controlled as follows. That is, the detection output of the current detector 13 is transferred to the first-order delay circuit 1.
9 to obtain an output delayed in time with respect to the armature current I _M , this output and the detection output of the rotation speed detector 14 are input to the multiplier 15, and the result is input to the gate signal generator 16. By inputting the current i c to the auxiliary winding 8, the current i _c that lags in the auxiliary winding 8 is controlled in the same manner as in the conventional example described above.

As a result, when the rotational speed N is constant and the armature current I _M suddenly changes, the current i _c of the auxiliary winding 8 lags behind the change in the armature current I _M. Incidentally, i _c ' shown by a broken line is the current in the auxiliary winding 8 without the primary lag circuit 19, and changes immediately without any time delay with respect to changes in the armature current I _M. As a result, the magnetic flux φ _c caused by the auxiliary winding 8 reduces the commutating magnetic flux φ _IP (which is delayed in time with respect to the change in the armature current I _M due to the influence of the eddy current in the commutating magnetic path).
The rise of φ is delayed compared to the magnetic flux φ _c ′ (indicated by the broken line) due to the auxiliary winding without the primary lag circuit 19, and the total interpolation magnetic flux _φ Compared to the magnetic flux φ〓 _IP ′ (indicated by the broken line), it follows changes in the armature current I _M better. In other words, good rectification compensation can be performed even when load fluctuations are large. Moreover, the first-order lag circuit 19 is inserted in the output circuit of the current detector 13, and the first-order lag circuit including a reactor that adversely affects the switching frequency of the semiconductor switching element 18 is not inserted in the circuit of the auxiliary winding 8. By setting the switching frequency of the semiconductor switching element high, good rectification compensation can be performed during steady operation without narrowing the no-spark zone of the DC machine.

Note that with respect to changes in the rotational speed N, the interpolation magnetomotive force is controlled so that the load axis is centered on the no-spark zone, as in the conventional example.

In the embodiment described above, the first-order lag circuit 19 is replaced by the multiplier 15.
Although the first-order delay circuit 19 is provided before the multiplier 15, it goes without saying that the first-order lag circuit 19 may be provided after the multiplier 15 in the case of a DC machine in which there is no sudden change in rotational speed.

〔Effect of the invention〕

As explained above, according to the present invention, the primary lag circuit is provided so that the current in the auxiliary winding does not change immediately in response to a change in the armature current, but changes with a time delay. Even when there is a sudden load change, the total interpolation magnetic flux follows changes in the armature current well, making it possible to perform good commutation compensation. Moreover, the first-order lag circuit is provided on the output circuit side of the armature current detection means,
Since the auxiliary winding circuit does not have a primary lag circuit including a reactor that adversely affects the switching frequency of the semiconductor switching element, the switching frequency of the semiconductor switching element can be set high to maintain the non-sparking band of the DC machine during steady operation. Good rectification compensation can be performed without narrowing the

[Brief explanation of drawings]

Fig. 1 is an exploded view of the main parts of a conventional DC machine, Fig. 2 is a characteristic diagram showing the phenomenon of movement of the non-sparking zone with respect to rotational speed, Fig. 3 is a block circuit diagram of a conventional rectification compensator, and Fig. 4 is FIG. 5 is a block circuit diagram of a rectification compensation device according to an embodiment of the present invention, and is an explanatory diagram of the operation of the rectification compensation device. 1... Yoke, 2... Main pole, 3... Complementary 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...first-order lag circuit.

Claims (1)

[Claims] 1. A rotor with an armature and a commutator, a main pole consisting of a field core and a field winding, a commutator core, a commutator winding, and a differentially wound auxiliary pole winding. A stator having a commutating pole consisting of a winding and a brush, an external DC power supply supplying current to the auxiliary winding, a current control circuit consisting of a semiconductor switching element, an armature current detecting means, and a rotation speed detecting means. , a multiplier that multiplies these detected values, and a gate signal generation circuit that generates a gate signal according to the output of the multiplier, and transmits and receives power to the armature through the brush and commutator. and controlling the switching frequency and conductivity of the current control circuit by the gate signal to control the current flowing to the auxiliary winding, wherein a primary voltage is provided between the armature current detection means and the multiplier. A rectification compensator for a DC machine, characterized by being provided with a delay circuit.