WO2018095852A1

WO2018095852A1 - Wind power plant and 3-phase inductor unit

Info

Publication number: WO2018095852A1
Application number: PCT/EP2017/079749
Authority: WO
Inventors: Juri WILHELM; Harald Lindhorst
Original assignee: Wobben Properties Gmbh
Priority date: 2016-11-22
Filing date: 2017-11-20
Publication date: 2018-05-31
Also published as: DE102016122435A1

Abstract

The present invention comprises a wind power plant (100), having at least one inverter (130) and at least one 3-phase inductor unit (200) which is coupled between the inverter (300) and an output (500) of the wind power plant (100), wherein the 3-phase inductor unit (200) has four or five limbs (210-250), each having a first and second end, a first and second yoke (260, 270) and a magnetic coupling unit (280), wherein the magnetic coupling unit (280) is coupled to all of the four or five limbs (210-250), serves as a magnetic bypass and is arranged between the first and second ends of the four or five limbs (210-250), wherein there is an air gap (281) between the magnetic coupling unit (280) and each of the four or five limbs (210-250), wherein the first, second and third limbs (210-230) each have a phase of a first and second primary winding (L11, L21, L31; L12, L22, L33).

Description

Wind turbine and 3-phase throttle unit

The present invention relates to a wind energy plant and a three-phase choke unit.

Electromagnetic three-phase choke coils, also referred to simply as a choke, which are used to confine current particles in electrical leads, to buffer energy, to adjust impedance, and / or to filter, are well known. Such chokes can be used at the output of an inverter to form 1.2 / modulated current sinusoidal as possible before it is fed into an electrical supply network. The choke is thus arranged between the inverter and the electrical supply network, in which the energy is to be fed.

In particular, in wind turbines, which have inverters, the chokes between the inverter and the supply network are provided. In a wind turbine with a three-phase system, a reactor is typically used for each phase or a 3-phase reactor is used. The three droops of a three-phase system can be combined into a three-phase choke. For this purpose, a composite of stacked sheets magnetic core can be provided, which has approximately the appearance of eight of a digital display. As a result, three magnetically interconnected legs are provided, each receiving a winding of a phase. A magnetic field, which results from a current of a winding in the magnetic leg of this winding, runs in part through the other two magnetic legs of the other two windings. As a result, the magnetic fields of all three windings and thus all three phases are superimposed.

Such 8-shaped magnetic cores typically have a very high magnetic permeability, so that the electrical properties of the throttles are essentially determined by the windings. A disadvantage of such chokes, however, is that the throttle is not completely symmetrical, because two coils are arranged on a respective outer magnetic leg, whereas one of the coils in a magnetic leg is disposed between the two outer legs. As a result, the magnetic fields of the windings, namely in particular between the two outer windings on the one hand and the winding arranged centrally in between, on the other hand can differ. There may be any stray fields and effective for the middle winding magnetic resistance may be slightly lower than the respective effective for the two outer windings magnetic resistance.

Due to the increasing performance of the electrical components in the field of power electronics even the smallest structural asymmetries, especially in the field of three-phase coils can lead to an inadmissible or at least undesirable heating of the coils.

In the priority German patent application, the German Patent and Trademark Office has researched the following documents: DE 10 2013 208 911 A1, DE 1 056 731 A1 and US 2006/0250207 A1. It is the object of the invention to provide a wind turbine and a three-phase choke unit, which avoid the above-mentioned disadvantages.

This object is achieved by a wind turbine according to claim 1 and by a 3-phase throttle unit according to claim 7.

The present invention thus relates to a wind energy plant with at least one inverter and at least one 3-phase throttle unit, which is provided between the inverter and an output terminal of the wind turbine. The throttle unit is configured as a four- or five-legged 3-phase throttle unit. The throttle unit has three legs each with at least one primary winding. The fourth and fifth legs are return legs and outer legs, respectively. The four or five legs each have first and second ends. Furthermore, the throttle unit has a first and a second yoke, which is respectively coupled to one end of the four or five legs. Furthermore, the throttle unit has a coupling unit which is coupled to all five legs, serves as a magnetic bypass and is arranged between the first and second ends of the five legs and has an air gap between the coupling unit and the legs. According to one aspect of the invention, the wind turbine can have at least two inverters and at least two three-phase throttle units.

Optionally, the coupling unit is arranged centrally along the length of the five legs. Above the coupling unit and below a first yoke each have a primary winding is provided around one of the first, second and third legs. Between the coupling unit and the second yoke in each case three further primary windings are provided around the first, second and third legs, so that a two-phase system is obtained.

According to the invention, a magnetic bypass is provided in the form of the coupling unit. According to one aspect of the present invention, a coupling factor of> 0.3 and <0.7 is achieved.

Further embodiments of the invention are the subject of the dependent claims.

Advantages and embodiments of the invention are explained below with reference to the drawing.

Fig. 1 shows a schematic representation of a wind turbine according to the invention;

FIGS. 2A to C show various views of a throttle unit according to a first embodiment of the invention;

3A and B each show a view of a throttle unit according to a second embodiment of the invention,

4A and B show various views of a throttle unit according to a third embodiment of the invention and

Fig. 5 shows a schematic representation of the inverter and a throttle unit according to a fourth embodiment.

Fig. 1 shows a schematic representation of a wind turbine according to the invention. 1 shows a wind energy plant 100 with a tower 102 and a nacelle 104. A rotor 106 with three rotor blades 108 and a spinner 110 is arranged on the nacelle 104. The rotor 106 is set in rotation by the wind in rotation and thereby drives a generator in the nacelle 104 at. The wind energy plant Typically, ge 100 has a power cabinet in the region of its base, in which the DC voltage of a DC intermediate circuit is converted by means of inverter 300 into an AC voltage. Such an inverter typically has a choke 200 which is coupled between the inverter and an output of the wind turbine.

FIGS. 2A to C show various views of a throttle unit according to a first embodiment of the invention. The throttle unit 200 according to an embodiment of the invention has five (or optionally only four legs) legs 210-250, wherein the first three legs 210, 220, 230 each have a first primary winding L11, L21, L31 of a first 3-phase system , The fourth and fifth legs 240, 250 serve as Rückflußschenkel or outer legs and have no windings. The first ends of the five or four legs 210-250 are coupled to a first yoke 260 and the second ends of the four or five legs 210-250 are coupled to a second yoke 270. The first and second yokes 260, 270 each extend over the length or width of the throttle unit.

Furthermore, the throttle unit 200 has a magnetic bypass in the form of a coupling unit 280, which is optionally arranged in the middle between the first and second ends of the four or five legs 210-250. The coupling unit 280 is arranged on both sides of the four or five legs 210-250. Further, an air gap 281 between the four or five legs 210-250 and the coupling unit 280 is provided in each case.

Optionally, the fourth and fifth legs may have a winding, e.g. To lead unbalanced magnetic components evenly between the fourth and / or fifth legs, so that it can come to a uniform heating within the core. Further, the windings on the fourth and fifth legs may serve for symmetry or filtering.

Optionally, the first to third legs 210-230 may have second primary windings L 2, L22, L32 of another 3-phase system. The first primary windings L11, L21, L31 are provided between the first yoke 260 and the coupling unit 280. The second primary windings L12, L22, L32 are provided between the coupling unit 280 and the second yoke 270. Optionally, the primary windings L11, L12 are connected in series. Further, the primary windings L21 and L22 and L31 and L32 are connected in series. In particular, on both sides of the leg between the five legs 210-250 and the coupling unit 280 each have an air gap 281 is provided.

The choke unit according to the invention is advantageous over two uncoupled 3-phase chokes, because here less winding material is required for the windings. The core of the throttling unit according to the invention is also advantageous over three cores, each with one phase, because less material is used.

The throttle unit according to the invention thus preferably has a ferromagnetic core with the five legs 210-250, the first and second yokes 260, 270 and the magnetic coupling unit 280. The two yokes 260, 270 are arranged substantially orthogonal to the five legs. The ferromagnetic core has a central axis which extends through the second leg. The five legs 210-250 of the ferromagnetic core each have central axes which extend in a plane parallel to each other.

The ferromagnetic core can be laminated as a powder core, for example, manganese-zinc ferrite or designed as an electric sheet.

The coupling, which is achieved by the coupling unit 280, can be adjusted, for example, by varying the air gap 281.

3A and B each show a view of a throttle unit according to a second embodiment of the invention. The throttle unit according to the second exemplary embodiment has four or five legs 210-250, wherein the first three legs 210-230 are surrounded by the fourth and fifth legs 240, 250. The throttle unit 200 further includes first and second yokes 260, 270 coupled to first ends of the first three legs. The second yoke 270 is coupled to second ends of the first, second and third legs. In contrast to the first and second yoke according to the embodiment of FIG. 2A, the first and second yokes 260, 270 did not extend over the entire width or length of the throttle unit. Rather, the fourth and fifth legs 240, 250 extend over the entire height of the throttle unit, so that the fourth and fifth legs define the first and second yoke 260, 270. Further, a coupling unit 280 is provided, which is coupled to all legs 210-250, wherein an air gap 281 between the respective legs 210-250 and the coupling unit 280 is present. A first three-phase primary winding L11, L21, L31 is provided on the respective first, second and third legs 210-230 between the coupling unit 280 and the first yoke 260. A second three-phase primary winding with the windings L12, L22, L32 is provided on the first, second and third legs 210-230 between the coupling unit 280 and the second yoke 270.

In Fig. 3B is a side view of the throttle unit according to the second embodiment is shown. The throttle unit is designed here O-shaped. In particular, the fourth or fifth leg 240, 250 is shown in FIG. 3B. The fourth or fifth leg 240, 250 is then configured O-shaped. Schematically, the first phase L11 of the first primary winding and the first phase L12 of the second primary winding are also shown. The fourth or fifth legs 240, 250 are thus located at both ends of the coupling unit 280 and the first and second yoke 260, 270.

4A and B show various views of a throttle unit according to a third embodiment of the invention. The throttle unit has four or five legs 210-250, the first, second, and third legs 210-230 having first and second primary windings. The throttle unit further includes a first yoke 260, a second yoke 270, and the fourth and fifth legs 240, 250 coupled to the first and second yokes 260, 270.

FIG. 4B shows a side view of the throttle unit according to the third exemplary embodiment. The fourth and / or fifth legs 240, 250 delimit, as in the second embodiment of Fig. 3A, the first and second yoke, but the legs are not O-shaped, but designed as a metal sheet or yoke.

Fig. 5 shows a schematic representation of the inverter and a throttle unit according to a fourth embodiment. According to the fourth embodiment, two inverters 300 are respectively coupled to a first primary winding L11, L21, L31 and a second primary winding L12, L22, L32 of the throttle unit 200. The throttle unit can be configured as in the first, second or third embodiment. The output of the throttle unit is coupled to an output 500 of the wind turbine or represents this output. With the throttle unit 200 according to the invention, a coordinated parallel connection of two or more inverters 300 can be provided.

According to the first embodiment, the legs can be realized as stamped sheets or as beams. The fourth and fifth legs according to the second embodiment The embodiment of FIG. 3A may be configured as wound sheets. The fourth and fifth legs 240, 250 according to the third embodiment are attached to the sides of the first and second yokes 260, 270. By the fourth and fifth legs 240, 250, which are configured in an O-shape, a magnetic coupling can be achieved. In particular, in this way a larger magnetically effective cross section can be achieved.

In Fig. 2A, on the one hand, a magnetic flux M1 and a magnetic flux M2 is shown, wherein the first magnetic flux M1 is generated by the coil L11 and the second magnetic flux M2 is generated by the coil L12. The respective coils L11 and L12 generate an opposing magnetic field M1, M2. These two magnetic fluxes M1, M2 add up in the coupling element 280. The coupling factor can be adjusted in particular by the air gap between the coupling unit 280 and the respective first, second or third limbs.

According to the invention, the coupling factor corresponds to the ratio of the voltages on the windings L11 and the winding L12.

Claims

claims

Wind energy plant (100), with

at least one inverter (130) and

at least one 3-phase throttle unit (200), which is coupled between the inverter (300) and an output (500) of the wind turbine (100),

wherein the 3-phase choke unit (200) has four or five legs (210-250) each having first and second ends, first and second yokes (260, 270), and a magnetic coupling unit (280),

wherein the magnetic coupling unit (280) is coupled to all of the four or five legs (210-250), serves as a magnetic bypass and is disposed between the first and second ends of the four or five legs (210-250),

wherein there is an air gap (281) between the magnetic coupling unit (280) and each of the four or five legs (210-250),

wherein the first, second and third legs (20-230) each have a phase of first and second primary windings (L11, L21, L31; L12, L22, L33).

Wind energy plant according to claim 1,

wherein windings of the first and second primary windings (L11, L21, L31, L12, L22, L33) provided on the first, second and third legs (210-230) are coupled together.

Wind turbine according to claim 1 or 2, wherein

two inverters (300) are coupled to a three-phase choke unit (200), wherein a first inverter (300) is connected to the first primary windings (L 1, L21, L31) and a second inverter (300) is connected to the second primary windings (L12 , L22, L33) is switched.

Wind turbine according to claim 1, 2 or 3, wherein

a coupling factor of the magnetic coupling unit (280) through the air gap (281) is adjustable.

Wind turbine according to claim 3, wherein

the coupling factor is> 0.3 and> 0.7, in particular 0.5.

6. Wind turbine according to one of claims 2 to 5, wherein in each case a first end of the first and second primary windings each having one of the inverters and a respective second end of the first and second primary windings is coupled to an output.

7. 3-phase throttle unit, with

four or five legs (210-250) each having a first or second end, a first yoke (260) coupled to first ends of the four or five legs (210-250),

a second yoke (270) each coupled to second ends of the four or five legs (210-250),

a magnetic bypass in the form of a magnetic coupling unit (280) coupled to each of the four or five legs (210-250) via an air gap (281) and between the first and second ends of the four or five legs (210-250) is arranged

wherein the first, second and third legs (210-230) have respective first and second primary windings (L11, L21, L31, L12, L22, L33).

8. 3-phase throttle unit according to claim 7,.

wherein the windings of the first and second primary windings (L11, L21, L31; L12, L22, L33) on the first, second and third legs (210-230) are respectively coupled together.

9. 3-phase throttle unit according to claim 6 or 7, wherein

the coupling factor of the coupling unit (280) through the air gap (281) is adjustable.

10. 3-phase throttle unit according to one of claims 6, 7 or 8, wherein

the coupling factor is> 0.3 and> 0.7, in particular 0.5.