DE4137457C1 - Voltage regulator for permanent magnet generator - reduces flux density by iris diaphragm closure and lowers generator voltage for stable supply - Google Patents

Abstract

The voltage regulator has an adjustable shutter (22) in the form of an iris diaphragm (22) made of a magnetic conducting material positioned between the permanent magnets (12) and the ring core (18). The flux density is reduced by the closing of the iris diaphragm and the voltage produced by the generator is lowered. The iris diaphragm is controlled by a mechanism (24) and the drive results using a servo motor (26). ADVANTAGE - Unit has lowest possible additional weight and constructional volume. Also gives increased generator output.

Description

The invention relates to a device for voltage regulation of generato with permanent magnets.

Permanent magnet generators have the property that depending on the Bela supply a different voltage. Most electrical ver consumers require an electrical voltage which must be relatively stable and may fluctuate only a few percent. This problem is usually caused by solved the following measures:

• - Voltage regulation by control electronics
  Disadvantages: relatively high weight, complicated circuitry, impairment of the overall efficiency due to heat loss, large construction volume due to cooling surfaces, active cooling using a fan, high manufacturing costs, high interference pulses, susceptible to load changes
• - Construction of a magnetic opposing field
  Disadvantages: similar to control electronics
• - Regulation by changing the speed
  Disadvantage: relatively sluggish, since the drive unit must be controlled (e.g. internal combustion engine). No constant frequency, relatively complex, expensive.
• - Change in the air gap between permanent magnets and iron core (DE-AS 10 88 600)
  Disadvantages: great effort, expensive.

Also known from US-PS 40 27 229 is a generator, in which in a constant gap between the permanent magnet and the ferro toroid magnetic elements in front of or away from the toroidal poles are, whereby the magnetic field of the rotor more or less that Toroid is fed.

The invention is based on the aforementioned US-PS 40 27 229 based on the task of a device for tension to create regulation with the lowest possible additional weight and Construction volume comes along, and that also with high generator power is feasible.

The solution to this problem is the subject of the claim.

In the subject of the invention, the magnetic flux is diverted or partially redirected by inserting an iris diaphragm like in a camera between the magnet and the core. The insertion of the Iris diaphragm causes part of the magnetic flux from the north pole of the Magnet goes over the iris to the south pole of the magnet. With quite ge When the iris is open, the generator generates full voltage while at  closed iris, the magnetic flux completely over the iris de goes. The generator is switched off in this state.

The following advantages result from the invention:

• - compact design
• - inexpensive manufacture
• - stepless regulation possible
• - almost no external interference
• - Saving an expensive power electronics with the known Disadvantages such as on and off spikes
• - no performance limit
• - Space and weight saving construction
• - Can be installed inside the generator
• - no technically complex maintenance required (Troubleshooting)
• - robust construction
• - The overall efficiency of the generator is not affected pregnant, that means no heat loss.

The invention is explained in more detail below with reference to figures.

Show it:

Fig. 1 is a schematic axonometric view,

Fig. 2 and 3, view a generator according to the invention with partly closed iris diaphragm in a sectional view and plan and

FIGS. 4 and 5 a generator according to the invention with opened iris diaphragm in a sectional view and plan view.

The components shown for the explanation of the invention in the figures have the following reference numbers:

2 permanent magnet generator
4 rotor
6 stator
8 Air gap between the rotor and stator
10 magnetic disc
12 permanent magnets
14 drive shaft
16 hub
18 toroid
20 spool
22 iris diaphragm
24 mechanics
26 servomotor
28 slats of the iris

The generated voltage U of a permanent magnet generator 2 is dependent on the flux density B, which comes from the permanent magnet 12 . The voltage changes accordingly by changing the flux density. If the flux density is increased, the voltage increases. If the flux density is reduced, the voltage drops. Because of this law, it is possible to regulate the voltage U of the generator 2 by deliberately changing the magnetic flux density.

With the help of an adjustable iris 22 , which consists of a magnetically conducting material, the flux density is reduced by closing the iris 22 and the voltage generated by the generator drops, as shown in Fig. 2 ge.

By opening the iris diaphragm ( FIG. 3), the full flux density acts on the coil 20 ; the voltage U of the generator rises.

Control of the iris

The iris diaphragm 22 is controlled by means of a mechanism 24 (tooth rims, levers or the like). The drive takes place by means of a servomotor 26 .

Through an electronic circuit, not shown, the output span voltage U queried on the generator.

If the voltage is too high, the iris diaphragm 22 is closed by a pulse from the control electronics and the flux density is reduced. If the voltage is too low, the iris 22 is opened in the same way; Flux density B and voltage U increase.

Claims (1)

Device for voltage regulation of generators with permanent magnets, characterized in that there is an adjustable aperture ( 22 ) in the manner of an iris made of a magnetically conductive material in axial air gap machines between the permanent magnets ( 12 ) and the ring core ( 18 ).