JPH02228239A - Synchronous machine - Google Patents

Abstract

PURPOSE: To achieve good voltage adjustment along the entire number-of- rotation region of an engine with only a slight constitution and circuitry technology cost by using an uncontrolled-type power supply stabilizing circuit, in order to obtain the sufficiently stabilized voltage based on the voltage restriction depending on the number of rotation. CONSTITUTION: A rotor 11 is provided concentrically in the inside of a stator 10. The stator 10 supports a plurality of grooves 13. The magnetizing direction of neighboring permanent magnets 17 is rotated by 180 deg. by magnetic pole distribution. A rod is mounted on the periphery of a rotor-supporting body 15. A hollow cylinder 18 is rotatably coupled together with the rotor 11. At the same time, the permanent magnet 17 is fixed on the supporting body 15. Therefore, the permanent magnet 17 is securely attached, even for a high number of rotation. The hollow cylinder 18 has a slight width in the radial direction, extends to the entire length of the rotor 11 in the axial direction and protrudes beyond the rotor 11 on the side of the edge.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of Application The invention presupposes a synchronous machine, such as a three-phase current generator for a motor vehicle, as indicated in the preamble of claim 1.

PRIOR ART Synchronous machines of this type are known (see the publication "Alternating (!current Mac
hines”M, 0.8ay, 5th edition, 1984
, Pitman Publishing L.
Published by imlted, London, 546/54
(page 7), also offers a number of different rotor configurations, where the rotor's normally circular member is
Used as a support for embedded permanent magnets. When the ring-shaped rotor core has only one magnet (two bipole configuration), this core slips in the circumferential direction to prevent short-circuiting of the magnetic flux. Permanent magnets are housed in the rotor core, each projecting radially outwardly in the direction of radial magnetization in an alternating manner, in which case the individual magnets, which are separated from each other at the outer periphery, each further have a magnetic pole. Can support pieces.

Another known embodiment includes permanent magnets radially embedded in slits in the rotor member, with magnetization directions running alternately clockwise and counterclockwise. In this case, so-called wedge poles are inserted between the permanent magnets, and the outer end surfaces of these wedge poles project in the direction of the stator. Another known structure for embedding permanent magnets in the rotor member has the following points. That is, the side magnetized permanent magnets are provided in a non-radial position in the squirrel cage rotor, and in this case, the monitoring or control of the appropriate metal can be carried out at one distance from the circular permanent magnets of the rotor. The magnet is demagnetized (demagnetized) jj! , is to take care of the whole family. In this case, the material of the magnet may include or be made of a metal.

- It is numerically known to use synchronous machines in the form of three-phase current generators as a reliable energy source in motor vehicles. The current generated by this generator is rectified and used for further powering multiple loads and charging the vehicle battery. In this case, a high value is imposed on this generator, i.e. the speed f of the vehicle engine,
One foot voltage across the whole area, as maintenance free operation as possible, robust construction, light weight and long service life.

A typical three-phase current generator has a claw-shaped pole rotor configured as an inside pole machine. The excitation winding of this rotor is supplied with an excitation current via a slip ring which is placed on the rotor strip and has carbon brushes which are fixed to the casing.

Synchronous machines are also known which have a rotor excited by permanent magnets, the magnetic poles of which are made up of individual permanent magnets. This raccoon synchronous machine is significantly more robust and has less protection because slip rings are omitted, so it has a longer life and is much more efficient.

In the case of synchronous motors excited by permanent magnets, the problem naturally arises that the output voltage must be constant over the entire speed range of the vehicle engine. Without additional means, the voltage induced in the armature winding would rise with increasing rotational speed, so that the output voltage of the synchronous generator would also vary over a wide range. Therefore, there have been no proposals for controlling the magnetic flux of the magnetic pole wheel, that is, the effective magnetic flux of a synchronous machine excited by a permanent magnet.

For example, the inner pole rotor of a synchronous generator, which has individual poles, is divided into two rotor halves that are arranged axially next to each other. In order to reduce the pole wheel flux by increasing the rotational speed, the rotor halves are rotated in opposite directions.

By this means, the induced voltage is controlled, but the iron loss in the stator is completely maintained.

It is also known to construct the rotor as a claw-pole rotor with a permanent magnet core, and to reduce the main magnetic flux by reverse rotation of one claw-pole half. The disadvantage in this case is that the suction force is large and not linear. This poses a problem in adapting the properties of the spring that activates the counterrotation depending on the rotational speed of the claw pole halves.

It is also known to make the rotor axially displaceable so that it can be displaced away from the stator as the rotational speed increases. This reduces the active area of the stator holes and reduces the effective magnetic flux. This 1 yen worth of purchase is significantly reduced.Furthermore, the robustness and lifespan of the synchronous machine are impaired by complex mechanical parts.

An equally unsatisfactory solution is to adjust the axially varying air gap depending on the rotational speed by means of a relative displacement between stator and rotor.

All of the mechanical adjustments described above for controlling the effective magnetic flux in synchronous generators are only suitable for processes that change steadily and, moreover, require considerable machine outlays. Therefore, the above-mentioned adjustment cannot be carried out in practice, and it depends on the electrical 'vI4 adjustment.

For example, it is known to fit additional coils on the stator yoke of a synchronous machine, thereby controlling the armature winding flux using saturation regulation. The disadvantage in this case is that the winding volume required for the additional windings is also considerably larger than the winding volume 9 of the original stator winding or armature winding.

Moreover, the additional copper losses are significant, which significantly reduces efficiency.

For this purpose, rectifier bridge circuits in parallel-regular or series-regular or semi-regular form of the output voltage, which are intended for thyristor or transistor regulation, for example in motor vehicles, for the power-generating operation of synchronous machines with rectifier bridge circuits. is used.

In the case of parallel adjustment distortion, a thyristor or transistor placed at the output of an uncontrolled rectifier bridge circuit
When the generator current connected to the on-board power supply is not needed, it is short-circuited. The disadvantage is that energy consumption occurs even when generator current is not required by the on-board power supply. Efficiency is significantly lower due to high copper losses. Furthermore, a backward-connected diode is required between the thyristor output and the vehicle battery, which must carry the entire load current in the forward direction. During operation without a battery, the generator voltage at the thyristor rises sharply depending on the no-load characteristic. Therefore, the values of the semiconductor components for convenience must be selected for the extremely high cut-off voltages that occur in this case.

In the case of series regulation, a thyristor or transistor in series with the output of the uncontrolled rectifier glitch circuit routes the generator current to the on-board power supply as required.

When the generator current is not required in the onboard power supply, the thyristor or transistor interrupts the load circuit and synchronous power generation is created without load. The thyristor or transistor must therefore, on the one hand, switch the entire on-board power supply current and, on the other hand, serve a voltage fixation. This voltage fixing causes a high voltage to be generated when the output circuit is open.
It is set by the no-load voltage of the machine. This results in high current and voltage oscillations in the vehicle power supply, which impairs the electric-magnetic interaction.

In the case of a semi-controlled rectifier bridge circuit, the six diodes of the uncontrolled rectifier bridge circuit are replaced by six thyristors. These thyristors are operated using control devices of the phase-controlled or on/off regulated type.

This requires a complex control switching circuit in the control device, for example a separate trigger circuit for anti-phase control as well as a zero point retracing circuit.

Problems to be Solved by the Invention The object of the present invention is to construct a permanent magnet excited type synchronous machine of the type mentioned at the beginning as follows. The object of the present invention is to avoid the above-mentioned disadvantages of known synchronous machines with a small constructional and circuit technology outlay, and to achieve excellent voltage regulation over the entire speed range of the vehicle engine.

Means for Solving the Problem The aforementioned problem is solved in a synchronous machine as set forth in the preamble of claim 1, by the configuration shown in the characterizing part of claim 1. In this case, eddy current effects that occur under certain conditions are used to control the effective magnetic flux. The resultant magnetic field penetrating the air gap generates eddy currents in the field of non-magnetic dielectric material. The eddy current losses determined thereby depend on the frequency and increase with increasing rotational speed. With a corresponding value selection of this field field, these eddy current losses are
This becomes large enough to limit the rotational speed-dependent increase in the voltage generated across the armature winding.

Based on this voltage limit depending on the rotation speed, for example, when the synchronous machine of the present invention is used as a three-phase current generator for the DC electric field of an automobile, sufficient voltage and running can be achieved at the rotation speed of the vehicle engine. It is sufficient to use an uncontrolled type of power stabilization circuit to overcome the chain acid. No circuit-technically complex voltage regulators and/or magnetic field regulators are required. Since voltage regulation is performed by eddy currents and no voltage regulator is used, no disturbance voltage occurs due to peaks during switching of the regulator.

In this case, the rotor of the synchronous machine of the present invention is characterized by a simple structure, and further has a small moment of inertia. Therefore, in the case of the use of the same type of motor vehicle, the stresses in the V-shaped drive belt when the rotational speed changes occur even less.

The synchronous machine shown in claim 1 can be configured as shown in claims 2 and below.

A simple technical implementation of the eddy current field body according to the invention is made of copper,
This is achieved by a solid hollow cylinder made of aluminum, brass or other conductive non-magnetic material. A hollow cylinder of this kind is fitted onto the rotor and contracted, so that the inside of the hollow cylinder rests directly on the permanent magnets.

This hollow cylinder is used at the same time to position and store the permanent magnets on the support. Therefore, the centrifugal force acting on the permanent magnet, even at extremely high rotational speeds,
It can be easily absorbed mechanically.

When using eddy current effects for voltage regulation, instead of configuring the hollow cylinder as a solid mass as shown in another example, a cage-shaped structure is formed with a relatively large cutout as follows. It is enough. The rods extend axially over the rotor and are connected to each other at least at their ends via circular rings. In this case eddy current losses are created in these rods. Cage configurations of this type are also used for safe and secure positioning of permanent magnets.

In the case of a hollow cylinder that is valved as a solid body or a hollow cylinder that is valved as a cage shape, according to the present invention, at least the end face of the hollow cylinder is configured to protrude in the direction of the rotor end work Q. However, it is further molded into a ventilation fan. This eliminates the need for an additional cross-flow ventilator mounted on the rotor shaft.

The rotor has less inertia.

When mounting the permanent magnets on the periphery of the rotor, the permanent magnets are placed in such a way that they are sufficient for the desired stress, e.g. due to centrifugal force, when changing the load at the desired operating speed. In addition, according to the present invention, the catastrophic current region body can be constructed from a permanent magnet itself. This is because when the permanent magnet material itself is formed based on, for example, textile elements,
This is because it has conductivity. In this case, the shape, size and arrangement of the permanent magnets are a measure for the eddy current effects that affect the effective magnetic flux or the l1li pole wheel flux qI. As permanent magnet materials, for example samaricum (am) or combinations with rare earth elements such as neodymium (Nd') are used. For example, the usable material is 8m0
o or NdFeB.

In the case of the synchronous machine according to the invention, the voltage regulation is carried out by means of eddy current effects, so that a voltage stabilization circuit of the uncontrolled type is sufficient for a good voltage constant, as described above. According to the illustration, this circuit is connected in parallel to the output of a rectifier bridge circuit connected to the armature winding. A stabilizing circuit of this type, in its most advanced form, consists of a diode which is placed in parallel with the output of the rectifier bridge circuit via a pre-resistor. The regulated output voltage is derived directly from the Zener diode (n or npn).
The current is emitted from the emitter of the transistor. The collector-base section of this transistor is connected in series with the collector resistor and in parallel with the front resistor of the Zener diode.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The automatic military three-phase current generator shown in cross section in FIG. 1 as an illustration of the invention is shown in detail as a possible embodiment for a synchronous machine. This three-phase current generator has a stator 10 and a rotor 11. The rotor has a gap of 12
In order to maintain the
ing. The stator 10 supports a plurality of grooves 13 arranged around its periphery in a seam-like manner for accommodating three-phase stator windings or armature windings 14 . The armature gold wire is shown in FIG. 1 only by the @ line in the groove 13.

A rotor 11 of the permanent magnet excited type has a cylindrical support 15 made of ferromagnetic material. This support is mounted on the rotor shaft 16 so as to rotate together with the sword. Permanent magnets 17 are provided as rotor poles at the periphery of the carrier 150 with a radial or diametric magnetization direction.

The magnetization directions of adjacent permanent magnets 17 are each rotated by 1800 degrees due to the magnetic pole distribution. In this case, this permanent magnet can be constructed as a flat rod extending in the longitudinal direction of the rotor. These rods are arranged such that their sides touch each other on the circumference of the rotor support 15 which is formed in a cylindrical shape. Advantageously, the permanent magnet material is a material in combination with Naeto earth elements, which is fitted in such a way that its inner wall rests directly on the permanent magnet 17. This hollow cylinder 1B is rotatably connected to the rotor 11. This bonding is preferably effected by shrinkage. At the same time, the permanent magnet 17 is fixed in this position on the support 15, so that a secure mounting of the permanent magnet is achieved even at high rotational speeds. The thin-walled hollow cylinder 18 has a significantly small radial width and extends over the entire axial length of the rotor 11;
Furthermore, it protrudes beyond the rotor 11 on the end face side. Both protruding circles i! The edges can advantageously form a ventilation fan (not shown) for the cross-flow of the one-three-phase current generator. The hollow cylinder 18 is made of a conductive non-magnetic material such as copper, aluminum, brass, etc.

FIG. 2 shows an electrical circuit diagram of an on-board power source for an automobile. This power source is fed from the three-phase generator mentioned above. In this case, at 20 a car battery is shown. This vehicle battery is charged by a three-phase current generator to an on-board voltage UB of, for example, 12V.

A resistor 21 having a resistance value RL represents a direct current load connected to the on-board power supply of the motor vehicle.

a star-connected winding body 14a of a three-phase armature winding 14;
The winding ends ty, v, w of 14b, 14c are connected to a non-controlled rectifier bridge circuit 22. The output terminals of this bridge circuit are designated B+ and D-. The generator voltage U rectified across these terminals. appears.

A voltage stabilizing circuit 23 is connected to output terminals B+ and D- of the rectifier bridge circuit 22, and an automobile battery 20 and a current load 21 are connected to the output side thereof. An embodiment of this voltage stabilizing circuit 23 is shown in FIGS. 6 and 4.

As shown in FIG. 3, the voltage stabilizing circuit 23 is composed of a Zener diode 24 in the case of the most leap year.

This Zener diode is connected to the output sides B+ and D- of the rectifier bridge circuit 22 via a device resistance. The output voltage of the Zener diode 24 forms the stabilized DC voltage UA of the three-phase current generator for supplying the motor vehicle battery 20 and the current load 21 . The output terminals of the voltage stabilizing circuit 23 are indicated at 26 and 27 in FIG. The vehicle battery 20 is connected to a current load 21 at this output terminal.

Figure 4 shows a high voltage stabilizing circuit 2 which is a modified version of the circuit in Figure 3.
3' is shown. This circuit is expanded around transistor 28, which transforms the basic Zener diode circuit of FIG. 6 into a series type stabilizing circuit. pnp ) The emitter of the transistor 28 is the output terminal 26
The collector-base section of the transistor 28 is connected in series with the collector resistor 29 and in parallel with the pre-resistor 25'. - The stabilized output voltage of the voltage stabilizing circuit 23' is indicated by UA.

A three-phase current generator excited by a permanent magnet is driven by the vehicle engine via a rotor shaft 16 at a rotation speed dn. This rotational speed varies within a wide range depending on the operating conditions of the vehicle engine.

The pole wheel flux generated by the rotor 11, which is excited by the permanent magnets, is designated φp in FIG. As the rotor 11 rotates, this pole wheel flux induces a voltage (KMIF) in the armature winding 14. This voltage causes a current flow in the armature winding 14 when the current load 21 is connected. This armature current creates a magnetic field across the armature. This magnetic field weakens the magnetic flux in the pole wheel. The resultant effective magnetic flux acting in the air gap 12 provides a measure for the voltage induced in the armature winding 14.

This effect flux causes eddy currents in the hollow cylinder 18, which causes eddy current losses. This eddy current loss depends on the frequency and increases as the rotational speed increases. If the available degrees of freedom are designed accordingly, for example if the dimensions of the hollow circle are set accordingly, then the value of this eddy current can be determined in such a way that the induced voltage increases depending on the rotational speed. Can be configured to limit. Voltage regulation is thereby achieved. A substantial voltage drift of the output voltage of the three-phase current generator is therefore achieved over the entire speed range of the vehicle engine without additional construction. Therefore, in order to satisfy the demand for a vehicle tower-mounted power supply, the above-mentioned non-controlled type stabilizing circuits 23 and 2 shown in FIG.
3' is sufficient.

A cage-shaped structure is obtained by forming a notch in the sword direction in the hollow circle mT1tj of the mass solid body shown in FIG. In this case, this hollow cylinder 18 is constructed from an axial rod. The rods can extend over the entire axial length of the rotor 11 and are further connected to each other at least at the ends by circular rings. This type of cage-shaped cypress is sufficient to form eddy currents, so that the eddy 11t flow effect can also be generated in a three-phase current generator.
It can be used for speed-dependent voltage regulation.

A particularly cost-effective method for creating eddy currents is to mount the permanent magnets 17 on the periphery of the support 15 as follows. The permanent magnets in this case are sufficient to cope with the stresses expected due to centrifugal forces in the event of a change in load and in response to the required operating speed of the vehicle engine. This allows the hollow circular portion 18 as a support element to be omitted. The permanent magnet 1.gamma., the permanent magnet material of which is electrically conductive, is in this case constructed and arranged as follows. That is, the separately described structure and arrangement are made so that a region body that rotates together with the rotor 11 is formed in the cavity 12 in the same way as in the case of the hollow cylinder 18 of the mass solid body or the hollow cylinder in the cage-shaped structure. It is done. As a result of the electrical conductivity of the permanent magnet material, eddy currents naturally form within the magnet material. Therefore, in this case as well, the rotation-dependent voltage regulation is automatically adjusted.

The features shown in the claims as well as in the drawings, both individually or in any combination with one another, constitute the essence of the invention.

Effects of the Invention The present invention provides voltage-based acid resistance that is independent of the rotational speed of a vehicle engine.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of an embodiment of a three-phase synchronous generator for automobiles, and Figure 2 is a cross-sectional view of an automobile tower connected to this synchronous generator.
The circuit diagram of IC#, Figures 3 and 4 are the first and second circuit diagrams.
FIG. 3 shows a valley circuit diagram of a voltage stabilization circuit corresponding to an embodiment.

Claims (1)

[Claims] 1. In a synchronous machine having a stator that supports armature windings and a permanent magnet rotor that rotates within the stator while maintaining an air gap, a conductive non-magnetic material is used. A region body (18) having a rotor (11) is provided, the region body having a rotor (11) in a gap (
12) so that it surrounds and rotates with the rotor without slipping, and furthermore, the region body is configured in such a way that rotational speed-dependent eddy currents are formed in it, which eddy currents limit the induced voltage. A synchronous machine characterized by: 2. Synchronous machine according to claim 1, characterized in that the area body (18) has a small radial extension. 3. The area body is composed of a thin-walled hollow cylinder (18) of a mass solid body made of copper, aluminum, brass, etc., and the hollow cylinder is placed on the rotor (11) and is compressed, for example, by shrinking. Claim 1 or 2, wherein the rotor is rotatably coupled with the rotor.
Synchronous machine as described. 4. The area body is composed of a cage-shaped hollow cylinder made of copper, aluminum, brass, etc., which is rotatably connected to the rotor (11), and the hollow cylinder extends in the axial direction of the rotor (11). 2. A synchronous machine according to claim 1, further comprising rods that are connected to each other at least at their ends. 5. Permanent magnets (17) forming rotor poles are provided on a support (15) made of ferromagnetic material, which is rotatably fixed on the rotor shaft (16); Furthermore, a hollow cylinder (18) has an inner wall that is connected to the permanent magnet (
5. A synchronous machine according to claim 3, further comprising a synchronous machine which is placed directly on the support (17) and is further adapted to fix the permanent magnets in their position on the support (15). 6. From claim 3, wherein the hollow cylinder (18) projects in at least one part beyond the rotor (11) in the axial direction, and the projecting cylindrical edge is formed to serve as a ventilation fan. The synchronous machine described in any one of items 5 to 5. 7. Permanent magnets (17) constituting the rotor magnetic poles are fixed on a support (15) made of a ferromagnetic material and rotatably placed on the rotor shaft (16). 2. A synchronous machine according to claim 1, wherein the field body is constituted by the permanent magnet (17) itself. 8. Make the permanent magnet (17) from a material containing rare earth elements,
8. A synchronous machine according to claim 5, wherein the synchronous machine is formed, for example, from a combination of samarium (Sm) and cobalt (Co) or from a combination of neodymium (Nd), iron (Fe) and boron (B). 9. Connect the winding ends (U, V, W) of the armature winding (14) to the rectifier bridge circuit (22), and further connect the output side (B^+, D^) of the rectifier bridge circuit (22). 8. A synchronous machine according to claim 1, wherein only a non-controlled voltage stabilizing circuit (23) is connected to the synchronous machine (1). 10. A voltage stabilization circuit (23) is connected in parallel to the output side of the rectifier bridge circuit (22), a pre-resistor (25)
), and furthermore, the output side (26) of the voltage stabilizing circuit (23) is connected from the connection point between the Zener diode (24) and the pre-resistor (25) to
Alternatively, the collector-emitter section of the npn transistor (28) is connected in series with the collector resistor (29) and connected in parallel with the pre-resistor (25) so as to be formed directly from the emitter of the npn transistor (28). A synchronous machine according to claim 9. 11. The permanent magnets (17) are flat rods that extend in the longitudinal direction of the rotor and are placed on the surface of the support (15) with their sides abutting each other. A synchronous machine according to any one of claims 1 to 10.