JP2817904B2 - DC machine rectifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectifier for improving rectification of a DC machine having an auxiliary pole coil.

[0002]

2. Description of the Related Art Conventionally, in a DC machine having an armature coil and a field coil, when a current flows through an armature coil, a magnetomotive force is generated in the armature core in a direction substantially perpendicular to the main magnetic field, and the main magnetic field is generated. It is known that an armature reaction that disturbs the distribution of the armature occurs, and in order to eliminate the armature reaction and perform good rectification, a DC machine is provided with an auxiliary pole. Then, as shown in FIG. 7, the armature coil 1 and the auxiliary coil 2
Are connected in series, and the same current as the current flowing through the armature coil 1 is also passed through the auxiliary pole coil 2, thereby canceling the magnetic flux generated by the armature reaction caused by the armature current.

[0003]

However, since the same current as the current flowing through the armature coil 1 flows through the auxiliary pole coil 2, there is a time lag from the actual spatial magnetic flux density.
Commutation may be deteriorated by overload. Also, compared to the magnetic saturation current in which the magnetization does not increase even if the magnetic field is further increased,
When a large amount of current flows through the armature coil 1, an extra current corresponding to the armature current also flows through the auxiliary pole coil 2, so that
There is a problem that efficiency is poor.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a rectifier for a DC machine which can always obtain good rectification and can improve the operation efficiency without flowing useless current to the auxiliary pole coil. The purpose is to provide.

[0005]

In order to achieve the above object, the present invention provides an armature coil wound on a rotor core energized through a commutator, a field coil wound on a field core,
And a rectifier for a DC machine having an auxiliary pole coil wound around an auxiliary pole core for improving rectification, wherein the auxiliary pole for controlling the auxiliary pole coil and a current flowing through the coil in parallel with the armature coil. And a magnetic flux of a geometric neutral axis between the field cores is set to 0 based on data calculated from a current flowing through the armature coil and a rotation speed of the armature coil. Thus, the current supply control of the auxiliary pole chopper is performed.

[0006]

According to the above arrangement, the gap magnetic flux between the field cores is calculated from the current flowing through the armature coil and the rotation speed of the armature coil, and the gap magnetic flux between the field cores is calculated based on the calculated data. The current flowing through the auxiliary pole coil is controlled by changing the conduction ratio of the auxiliary pole chopper so that the magnetic flux of the geometric neutral axis becomes zero. In this way, a good rectification can be obtained without a deviation between the geometric neutral axis and the electrical neutral axis. In addition, even when a current equal to or more than the magnetic saturation current flows through the armature coil, it is possible to prevent a useless current from flowing through the auxiliary pole coil.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a DC machine.
This circuit includes a series circuit of an armature coil 1, a commutator, a brush and a field effect transistor 11 (hereinafter abbreviated as FET) for controlling a current flowing through the armature coil 1, a supplementary pole coil 2 and this coil. FE for controlling the flowing current
This is a circuit in which a series circuit of T12 and a series circuit of a field coil 3 and an FET 13 for controlling a current flowing through this coil are connected in parallel. These are connected to a DC power supply E. The FETs 11, 12, and 13 form a chopper circuit, and each gate is connected to a control circuit (not shown). Diodes 21, 22, and 23 are connected to the respective coils in anti-parallel.

Next, the internal configuration of the DC machine will be described. FIG.
Is a side view of the DC machine, and FIG. 3 is a partial longitudinal sectional view. Four field cores 33 are radially arranged inside the DC machine, and the field coils 3 are wound around each of the field cores 33. The DC machine has an armature core 31 as a rotor.
An armature coil 1 wound around the armature core 31;
A commutator 5 and a brush 6 for performing commutation, a locker 7 for insulating the brush 6 from the case of the DC machine, and the like are provided.

Next, the operation of the above configuration will be described. The current data flowing through the armature coil 1 and the rotation speed data of the armature coil 1 are input to a control circuit (not shown), and the control circuit calculates the gap magnetic flux between the field cores 33. Then, based on the calculation data, the control circuit outputs a chopper pulse so that the magnetic flux of the geometric neutral axis between the field cores 33 becomes 0, thereby setting the FET1
2 (FIG. 1) is controlled to control the current flowing through the auxiliary pole coil 2. FIG. 4 is a magnetic flux density distribution curve in the gap between the field cores. The vicinity of the geometric neutral axis is rectified by the auxiliary pole coil 2 wound around the auxiliary pole core 32 to obtain a rectified magnetic flux B. As described above, the current flowing through the auxiliary pole coil 2 is chopper-controlled so that the rectified magnetic flux B becomes zero.

An armature current Ia flows through the armature circuit based on an induced voltage generated by rotation of the armature coil 1, and the armature current Ia generates an armature reaction magnetic flux φa. The induced voltage value induced in the armature coil 1 is a value φ obtained by subtracting the armature reaction magnetic flux φa generated by the armature coil 1 from the magnetic flux φm generated by the field coil 3.
And the rotation speed N of the armature coil 1. Since a current is caused to flow through the auxiliary pole coil 2 in order to cancel the armature reaction magnetic flux φa, the current flowing through the auxiliary pole coil 2 is unambiguous from two data, the armature current Ia and the rotation speed N of the armature coil 1. Is decided.

FIG. 5 is a time chart of the current flowing through the armature coil and the auxiliary pole coil. In a magnetically unsaturated state in which a current equal to or less than the magnetic saturation current I2 flows through the armature coil 1 (time 0 to t1 and t2), a current proportional to the armature current flows through the auxiliary pole coil 2. Conventionally armature coil 1
And the auxiliary pole coil 2 are connected in series. Therefore, even in a magnetic saturation state (time t1 to t2) in which a current equal to or higher than the magnetic saturation current I2 flows through the armature coil 1, the auxiliary pole current is represented by a dotted line in FIG. And increases with the armature current. On the other hand, according to the present invention, since the armature coil 1 and the auxiliary pole coil 2 have separate FETs and are in a parallel relationship,
In the magnetic saturation state, the auxiliary pole current can be kept at a constant low current I1 in order to prevent unnecessary current from flowing through the auxiliary pole coil 2. By doing so, energy can be saved only in the shaded portions in FIG.

The present DC machine can be applied both as a generator as shown in FIG. 6A and as an electric motor as shown in FIG. The N and S poles of the auxiliary pole core 32 are opposite between the case of operating as a generator and the case of operating as a motor.

[0013]

As described above, according to the present invention, the distance between the field cores is determined based on the gap magnetic flux data between the field cores calculated from the current flowing through the armature coils and the rotation speed of the armature coils. The current flowing through the auxiliary pole coil is controlled by the auxiliary pole chopper so that the magnetic flux of the geometric neutral axis becomes zero.
By doing so, compared to the conventional case where the same current as the armature current flows through the auxiliary pole coil, there is no time lag with the actual spatial magnetic flux density, so the rectification can be improved and the brush can be improved. Extend the life of the device. Further, since the auxiliary pole chopper for controlling the power supply to the auxiliary pole coil is provided, it is possible to prevent the useless current from flowing through the auxiliary pole coil and to improve the operation efficiency.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a DC machine according to an embodiment of the present invention.

FIG. 2 is a side view of the DC machine.

FIG. 3 is a partial vertical sectional view of the DC machine.

FIG. 4 is a magnetic flux density distribution curve in a gap between field cores.

FIG. 5 is a time chart of a current flowing through the armature coil and the auxiliary pole coil.

FIG. 6 is an explanatory diagram when the present DC machine is used as (a) a generator and (b) an electric motor.

FIG. 7 is a control circuit diagram of a DC machine according to the related art.

[Explanation of symbols]

 Reference Signs List 1 armature coil 2 auxiliary pole coil 3 field coil 11, 12, 13 field effect transistor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 23/00 H02K 23/24 H02K 23/66 H02P 7/06

Claims (1)

(57) [Claims] 1. An armature coil wound around a rotor core energized via a commutator, a field coil wound around a field core, and an auxiliary pole wound around an auxiliary pole core for improving rectification. In a rectifier of a DC machine provided with a coil, a series circuit of the auxiliary pole coil and an auxiliary pole chopper for controlling a current flowing through the coil is connected in parallel with the armature coil, and flows through the armature coil. Based on data calculated from the current and the rotation speed of the armature coil, the energization control of the auxiliary pole chopper is performed so that the magnetic flux of the geometric neutral axis between the field cores becomes zero. A rectifier for a DC machine, characterized in that: