JP2529187B2 - Rectifier compensator for DC machines - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a rectification compensator for a DC machine such as a motor or a generator having a commutator and a brush, and particularly to an auxiliary winding for adjusting the auxiliary pole magnetomotive force. About what you have.

[Background of the Invention]

It is no exaggeration to say that the rectification performance of a DC machine influences the performance and life of the machine, and many studies have been made in the past. The quality of the rectification performance is determined by measuring the sparkless zone for the actual machine. On the other hand, the DC machine has a phenomenon in which the non-spark zone moves depending on the number of revolutions. If the amount of movement of the non-spark zone is large, it becomes impossible to operate in non-spark rectification.

As a countermeasure against this, conventionally, a rectification compensation method shown in FIGS. 3 to 5 has been proposed (see Japanese Utility Model Laid-Open No. 50-99408).

FIG. 3 is an exploded view of a main part of a DC machine equipped with a conventional rectification compensation device. In the figure, 1 is a ring-shaped yoke, 2, 3
Are the main and auxiliary poles formed on the inner peripheral side, and 4 and 5 are the main poles 2
Main pole core and main pole windings that make up, 6,7,8 are auxiliary pole cores that make up the pole 3, auxiliary pole windings and auxiliary windings, 9 is a rotating armature, and 10 is the armature winding. It is a line. The main pole 2 applies a main magnetic flux to the armature winding 10, and the auxiliary pole 3 applies an auxiliary magnetic flux for generating a rectified electromotive force when a current flowing in the armature winding 10 is reversed. Further, the auxiliary winding 8 provided at the tip of the commutating pole core 6 is wound differentially with respect to the commutating pole winding 7, and as shown in FIG. As it moves toward the over-rectifying side (excessive commutation of magnetic poles), the magnetomotive force is adjusted to move the load shaft to the O-P line at the center of the non-spark zone.

FIG. 5 is a block circuit diagram of a device that controls the current amount of the auxiliary winding according to the rotation speed and the armature current to compensate for the non-spark band movement phenomenon. The part corresponding to FIG. The same reference numerals as in the figure are attached. 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, 17 is an external DC power supply, 18 is a thyristor, GTO thyristor, power transistor, etc. 2 is a current control circuit composed of the semiconductor switching element of FIG.

That is, this device controls the current i _c supplied from the external DC power supply 17 to the auxiliary winding 8 while flowing the armature current I _M through the auxiliary pole winding 7 as follows. That is, the outputs of the current detector 13 and the rotation speed detector 14 are input to the multiplier 15, the result is input to the gate signal generator 16, and the switching frequency of the current control circuit 18 is input by the gate signal obtained by this. In addition, the current passing through the auxiliary winding 8 is controlled by controlling the conduction ratio and the like. As a result, the current i _c of the auxiliary winding 8 changes according to the rotation speed and the armature current, so that the commutating magnetic force of the auxiliary pole changes, and as shown in FIG. Move to the OP line. As a result, the DC machine can be operated with no spark rectification.

However, if such a rectification compensation method is applied to a DC machine in which start-stop is frequently repeated, there is a problem that a large spark is generated from the brush, the brush is abnormally worn, and the commutator is roughly damaged.

[Object of the Invention]

The present invention has been made in view of this point, and an object thereof is to eliminate the above-mentioned problems and to perform rectification compensation of a DC machine that can perform good rectification compensation even when applied to a DC machine in which start-stop is frequently repeated. To provide a compensator.

[Outline of Invention]

The present inventor conducted and studied various experiments in order to investigate the cause of the above-mentioned problems. As a result, we found that the spark from the brush occurs only in the start mode, and becomes larger especially when the armature current changes rapidly.

The present invention has been made based on such a discovery, and in the rectification compensation method described above, a semiconductor switching element is used instead of the diode conventionally used as the one-way conductive semiconductor element for the flywheel circuit for auxiliary winding. (Second semiconductor switching element) is used,
The terminal voltage of the auxiliary winding is detected, and it is judged from the magnitude and direction whether it is the start-up time, and only when it is judged that it is the start-up time, the current flowing through the auxiliary winding via the flywheel circuit for the auxiliary winding is detected. The chopper is controlled by a semiconductor switching element.

Example of Invention

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the illustrated embodiments, but the result of an examination of the cause of the above-mentioned problems will be briefly described.

First, FIG. 6 shows the main circuit configuration of the current control circuit 18 adopting the tipper method in the rectification compensation device. In this figure, when the GTO thyristor (hereinafter, simply referred to as GTO) 19 is turned on, a current i _c1 is supplied from the DC power supply 17 to the auxiliary winding 8, and when the GTO 19 is turned off, the energy of the inductance of the auxiliary winding 8 assists the auxiliary winding 8. A current i _c2 flows through a flywheel diode (hereinafter simply referred to as F · D) 20 for winding. In addition, 21 is FD for GTO19, and 22 is a snubber circuit.

The problem here is that the auxiliary winding 8 always forms a closed circuit by F · D20 and is arranged in the same magnetic path as the auxiliary pole winding 7 as shown in FIG. Therefore, it has been found that the following drawbacks occur.

That is, in a DC machine in which start-stop is frequently repeated, when the armature current transiently increases or decreases, the armature current also flows in the commutating pole winding 7, so that the commutating pole flux also transiently changes. Then, a voltage is induced in the auxiliary winding 8 in accordance with this change in magnetic flux. In the steady operation mode, the current control circuit 18 operates and the required current i _c flows through the auxiliary winding 8. However, at the time of starting the transient operation mode, Fig. 7 (a), (b)
The induced voltage v _c1 shown in FIG. 7 is generated, and the induced voltage v _c2 shown in FIGS.
When the DC machine is operated in the pattern of the armature current I _M shown in FIG. 7 (e), the auxiliary winding 8 is shown in FIG. 7 (f).
Although the current i _c shown by the broken line should flow, the current i _c3 actually shown by the solid line in FIG. _7F flows, and an abnormal current flows at the time of startup.

As a result of studying the cause, when the auxiliary pole magnetic flux φ _IP due to the auxiliary pole winding 7 suddenly increases at the time of start-up shown in FIGS. A current flows so as to generate a magnetic flux φ _ax in the direction of canceling φ _IP . That is, the voltage v _c1 is generated in the auxiliary winding 8, and this voltage v
Due to _{c1, a} current i _c3 that cannot be controlled flows through F · D20. Further, at the time of stop shown in FIGS. 7 (c) and 7 (d), the voltage v _c2 generated in the auxiliary winding 8 is opposite to the voltage v _c1 generated at the time of start-up, so this voltage v _c2
The current does not flow. Therefore, the larger the rate of change of the armature current I _M at startup, the larger the voltage v _c1 induced in the auxiliary winding 8 and the uncontrollable current that flows in the auxiliary winding 8 according to this voltage v _c1. i _c1 also becomes large. Therefore, there is no problem when the width of the non-spark band of the DC machine is wide, but when it is narrow, the load axis OP line shown in FIG. From this, it was found that a large spark was generated, which caused abnormal wear of the brush and rough damage of the commutator.

FIG. 1 is a block circuit diagram of a rectifying / compensating device according to an embodiment of the present invention, which solves such a problem. In the figure, the parts corresponding to those in FIGS. 5 and 6 are designated by the same reference numerals.

This embodiment differs from the conventional example shown in FIGS. 5 and 6 in that the F / D20 for auxiliary winding is replaced with GTO23, and
A detector 24 for detecting the induced voltage in the auxiliary winding 8 is provided, and the gate signal generator 16 determines whether or not the starting time is based on the detected magnitude and direction of the induced voltage in the auxiliary winding 8.
The current control signal of the GTO 19 is supplied to the GTO 23, and the current i _c3 flowing in the auxiliary winding 8 at that time is controlled by the chipper so as to approach the current i _c shown by the broken line in FIG. 7 (f). Is.

Therefore, an abnormal current does not flow in the auxiliary winding at the time of startup, and good rectification compensation can always be performed.

FIG. 2 is a block circuit diagram of a rectifying / compensating device showing still another embodiment of the present invention. In the figure, parts corresponding to FIGS. 1, 5 and 6 are designated by the same reference numerals.

In FIG. 2, 35 is a current direction determination circuit, 25A to 25D are analog switches, 26 is a pulse generator, 27 is a current detector, 28A and 28B are two-way analog switches, 29 is an inverting circuit, and 30 is a command generator. Reference numeral 31 is a comparator, and 32 is an AND circuit. The current control circuit 18 is composed of power transistors 33A to 33D connected in an H-shape so as to supply a current in the forward and reverse directions to the auxiliary winding 8 and diodes 34A to 34D connected in parallel to the power transistors 33A to 33D. ing. Here, the current i _c flowing through the auxiliary winding 8 turns on the transistor 33D and turns on / off the transistor 33A, so that the DC power supply 17
Sourced from the same, and the reverse current flows through the transistor as well.
It is supplied by controlling 33B and 33C.

In such a configuration, the armature current I _M (solid line in positive direction, broken line in reverse direction) flows as in the conventional case. here,
When the armature current I _M is flowing in the positive direction, the current direction determination circuit 35 operates to turn on the analog switches 25A and 25D in the path of one of the output terminals a, and the analog switch 28B.
Transistor 33D is turned on via and maintains its state. On the other hand, the pulse generator 26 that receives the output of the multiplier 15 as an input
Since the ON signal from is supplied to the transistor 33A,
The transistor 33A is turned on, and the current i _c shown by the solid line from the DC power supply 17 flows through the auxiliary winding 8. After that, when the current i _c reaches a certain value, it is detected by the current detector 27 and is matched with the output of the multiplier 15. Therefore, the pulse generator 26 supplies an off signal to the transistor 33A, and this is output. Turn off. At this time, the current of the auxiliary winding 8 continues to flow through the transistors 33D and 34B due to the energy of its inductance. That is, the transistor 33A is turned on and off, and the amount of current flowing through the auxiliary winding 8 is controlled according to the output of the multiplier 15.

At the time of start-up, the induced voltage of the auxiliary winding 8 is detected by the voltage detector 24, this is compared with the command value from the command generator 30 by the comparator 31, and when the voltage exceeds the command value, the comparator 31 An ON signal is output, and this is input to one input terminal of the AND circuit 32. On the other hand, when the output of the pulse generator 26 is an off signal, the AND circuit 32 is passed through the inverting circuit 29.
The other input of is simply provided with an ON signal. Therefore, the AND circuit 32 outputs an ON signal and the analog switch
28B is switched, so transistor 33D is multiplier 15
ON / OFF control is performed according to the output of the. As a result, the current flowing due to the induced voltage of the auxiliary winding 8 can be controlled at the time of start-up, and an abnormal current as in the conventional case does not flow, and good rectification compensation can always be performed.

When the armature current I _M flows in the opposite direction as shown by the broken line, the analog switches 25B, 25C in the path of the other output end b of the current direction determination circuit 35 are turned on and the transistor 33B, 33 C causes the auxiliary winding 8 to have a current i _c indicated by a broken line.
Is supplied, an abnormal current is prevented from flowing in the auxiliary winding 8 by the same operation as in the case of the forward direction, and good rectification compensation can be always performed even at the time of starting.

〔The invention's effect〕

As described above, according to the present invention, the rectification compensation of the DC device in which the current flowing from the external DC power supply to the auxiliary winding according to the armature current and the rotation speed is chopper-controlled by the first semiconductor switching element. In the device, a semiconductor switching element (second semiconductor switching element) is used in place of the diode conventionally used as the one-way conductive semiconductor element for the auxiliary winding flywheel circuit, and the terminal voltage of the auxiliary winding is detected. Then, determine whether it is at startup from the size and direction, and only when it is determined at startup,
Since the current flowing in the auxiliary winding via the flywheel circuit for the auxiliary winding is chopper controlled by the semiconductor switching element, sparks from the brush are generated even when applied to a DC machine in which start-stop is frequently repeated. Therefore, good rectification compensation can always be performed.

[Brief description of drawings]

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, and FIG. 3 is a conventional DC machine. FIG. 4 is a characteristic diagram showing the movement phenomenon of the non-spark zone with respect to the number of revolutions, FIG. 5 is a block circuit diagram of a conventional rectification compensator, and FIG. 6 is a diagram of the current control circuit part of FIG. An electric circuit diagram showing the details and FIGS. 7 (a) to 7 (f) are operation explanatory views of the conventional rectification compensation device during a transition. 5 ... Main pole winding, 7 ... Complement pole winding, 8 ... Auxiliary winding, 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, 19,23 …… G
TO, 24 ... Voltage detector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Makino 3-1-1 Sachimachi, Hitachi City Inside the Hitachi factory, Hiritsu Manufacturing Co., Ltd. (56) References JP-A-60-26494 (JP, A) 55-82096 (JP, U)

Claims (1)

(57) [Claims] 1. A rotor having an armature and a commutator, a main pole composed of a main pole core and a main pole winding, a commutating pole core, a commutating pole winding, and this commutating pole winding are wound differentially. A stator having a commutating pole composed of an auxiliary winding and a brush, a means for detecting an armature current, a means for detecting the rotation speed of the rotor, and a detected armature current and rotation speed. A flywheel circuit for an auxiliary winding having a first semiconductor switching element that controls a current flowing from the external DC power source to the auxiliary winding in response to the chopper, and a one-way conductive semiconductor element connected in parallel with the auxiliary winding. And a means for detecting a terminal voltage of the auxiliary winding, and a magnitude of the detected terminal voltage in a rectification compensating device for a DC machine using the second semiconductor switching element as the one-way conductive semiconductor element. When starting from the direction Means for determining whether or not the current control signal of the first semiconductor switching element is supplied to the second semiconductor switching element only when it is determined at the time of start-up, through the flywheel circuit for auxiliary winding. A rectifying / compensating device for a DC machine, characterized in that a current flowing through an auxiliary winding is chopper controlled.