CN102195370B - Leakage reactance variable wide speed range output permanent magnet generator system - Google Patents

Abstract

The invention discloses a leakage reactance variable wide speed range output permanent magnet generator system, which relates to a leakage reactance variable wide speed range output permanent magnet generator system. The invention solves the problems of complex control and low reliability existing in the existing permanent magnet generator system. The number of rotor poles of the three-phase permanent magnet synchronous generator in the system of the present invention is 10n; The phase difference between the two sets of three-phase windings of the stator is 30 ° electrical angle; The number of slots of the stator core is 12n, two sets of three The phase windings are all concentrated windings. The 6n coils that make up each set of three-phase windings are evenly distributed along the circumference and wound on the armature core teeth. The set of windings with more turns is embedded in the bottom layer of the slot, and the other set The winding is embedded in the upper layer of the slot, and the leakage reactance regulator is between the upper winding and the lower winding; the output end of each set of three-phase winding is connected to the AC input end of a three-phase rectifier, and the DC output ends of two three-phase rectifiers are connected in parallel or After being connected in series, they are connected to the common DC bus. The invention is suitable for wind power generation system.

Description

Leakage reactance variable wide speed range output permanent magnet generator system

technical field

The invention relates to an output permanent magnet generator system with variable leakage reactance and wide speed range, which belongs to the field of motors.

Background technique

As a generator, the permanent magnet motor has many advantages due to the omission of the excitation winding and the collector ring and brush that are prone to failure: simple structure, reduced processing and assembly costs, more reliable operation, etc. The rare earth permanent magnet generator has significant advantages such as small size, light weight, high efficiency, and flexible shape and size of the motor; at the same time, due to the small permeability of the permanent magnet in the direct axis magnetic circuit, the direct axis armature The reaction reactance is much smaller than that of the electric excitation synchronous generator, so the inherent voltage adjustment rate is smaller than that of the electric excitation synchronous generator. Therefore, small wind turbines basically use permanent magnet synchronous generators.

In a wind power generation system, the output voltage of a wind generator (especially a permanent magnet generator) fluctuates in a wide range due to a wide range of wind speed. Therefore, small generators often cannot be directly connected to the load, but use a rectifier to convert the AC voltage and current in the armature winding into DC voltage and current, charge the battery, store the electric energy, and supply power to the load through the battery. See Figure 5 Shown; It is also possible to use a controllable rectifier regulator to make the generator supply power to the load and the battery at the same time.

However, the main problem of the current off-grid wind power generation system is that it cannot capture the maximum wind energy and realize the maximum power control, and the generator cannot output electric energy when the wind turbine is at a low speed; Difficulty, high cost, low reliability and other issues.

Contents of the invention

In order to solve the problems of complex control and low reliability existing in the existing permanent magnet generator system, the present invention proposes a permanent magnet generator system with variable leakage reactance and wide speed range output.

A leakage reactance variable wide speed range output permanent magnet generator system according to the present invention is composed of a three-phase permanent magnet synchronous generator and two three-phase rectifiers. The three-phase permanent magnet synchronous generator includes a stator, Rotor and air gap, the rotor is composed of permanent magnets, rotor yoke and shaft, the number of rotor poles is 10n; the stator is composed of iron core and two sets of three-phase windings, the phase difference between the two sets of three-phase windings is 30 ° electrical angle; the number of slots of the iron core of the stator is 12n, n is a positive integer, the two sets of three-phase windings are concentrated windings, each set of three-phase windings is composed of 6n coils, each set of three-phase windings The 6n coils are evenly distributed along the circumference and wound on the teeth of the armature core, that is, one coil is wound on every other tooth; the number of turns of the two sets of windings is different, and the set of windings with more turns is embedded in the bottom layer of the slot. Another set of windings with less is embedded in the upper layer of the slot, that is, close to the slot side, and a leakage reactance adjustment piece made of magnetic material is arranged between the upper layer winding and the lower layer winding; the output end of each set of three-phase windings is connected to a three-phase After the AC input terminal of the rectifier and the DC output terminals of the two three-phase rectifiers are connected in parallel or in series, they are connected to the common DC bus.

The leakage reactance variable wide speed range output permanent magnet generator system of the present invention belongs to the wide speed range output permanent magnet wind power generator system. The working principle of this kind of generator system is:

For a wide speed range output permanent magnet generator system composed of a double-winding generator and two rectifiers, because the number of turns of the two sets of windings in the generator is different, the back EMF of the winding with more turns is higher than that of the winding with fewer turns of back electromotive force. When the speed of the generator is low, the winding with more turns will have power output. As the speed of the generator increases, the output power and current of the winding with more turns will also increase, but due to the winding with more turns The notch width of the slot where the coil side is located is small and the notch height is high. Therefore, the leakage reactance of the winding with many turns is large, which suppresses the increase of the output voltage at high speed, thereby limiting the output power at high speed and ensuring that it will not Damaged by current exceeding the limit value. Windings with few turns have output only when the generator is at high speed, and because of the small leakage reactance of windings with few turns, windings with few turns can output large current and high power.

Figure 4 is the power output characteristic of the generator system. It can be seen from the figure that the total output power curve of the system is close to the maximum output power curve of the wind turbine, so the power generation system can adapt to the characteristics of the wind turbine, can realize automatic tracking of the maximum wind energy, and can effectively improve power generation. Electromechanical energy conversion capability when the machine speed changes. The invention can be widely used in variable-speed power generation fields such as vehicle power generation, wind power generation, and small hydropower generation.

The invention uses a special armature structure to make the leakage reactance of the winding variable with the output current, thereby limiting the output power of the winding, and using the combined output of two sets of windings to realize the follow-up of the output power of the generator from low speed to high speed, and to enhance The electromechanical energy conversion efficiency of the generator is improved; in addition, the generator system is composed of two sets of winding permanent magnet synchronous generators and two rectifiers. The wave currents cancel each other out, making the armature magnetomotive force sinusoidal.

The permanent magnet generator system of the present invention has the advantages of simple structure, low vibration and noise, high efficiency, small output voltage pulsation, strong overload capacity, high reliability and low manufacturing cost, etc. On the basis of the wind power system, the maximum wind energy automatic tracking control of the wind power generation system is realized, which greatly improves the ability to convert wind energy into electrical energy under the condition of wind speed changes.

Description of drawings

Fig. 1 is the electrical schematic diagram of the leakage reactance variable wide speed range output permanent magnet generator system according to the present invention, and Fig. 2 is the leakage reactance variable wide speed range output permanent magnet generator system described in the second specific embodiment The structural representation of the permanent magnet motor, Fig. 3 is the structural representation of the permanent magnet generator in the leakage reactance variable wide speed range output permanent magnet generator system described in Embodiment 4, Fig. 4 is the curve of the permanent magnet generator system Figure, wherein curve 11 represents the situation that the maximum wind power output power is equal to the generator input power, curve 12 represents the total output power of the permanent magnet generator, and curve 13 represents the output power of winding 2 with many turns, and Fig. 5 is the existing small Electrical schematic diagram of a wind power system.

Detailed ways

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 1. The leakage reactance variable wide speed range output permanent magnet generator system described in this embodiment is composed of a three-phase permanent magnet synchronous generator and two three-phase rectifiers. The three-phase permanent magnet synchronous The generator includes a stator, a rotor and an air gap. The rotor is composed of a permanent magnet 6, a rotor yoke 7 and a rotating shaft, and the number of poles of the rotor is 10n; the stator is composed of an iron core 1 and two sets of three-phase windings. The phase difference between the windings is 30° electrical angle; the number of slots of the stator core 1 is 12n, n is a positive integer, the two sets of three-phase windings are concentrated windings, and each set of three-phase windings is composed of 6n coils , the 6n coils in each set of three-phase windings are evenly distributed along the circumference and wound on the armature core teeth 4, that is, one coil is wound on every other tooth; the number of turns of the two sets of windings is different, and the set of windings with more turns is 2 Placed at the bottom of the slot, another set of windings 3 with fewer turns is embedded in the upper layer of the slot, that is, near the notch side, and a leakage reactance adjusting piece 5 made of magnetic material is arranged between the upper winding and the lower winding; each set The output end of the three-phase winding is connected to the AC input end of a three-phase rectifier, and the DC output ends of the two three-phase rectifiers are connected in parallel or in series, and then connected to the common DC bus.

Referring to FIG. 1 , it is a schematic diagram of the principle of the leakage reactance variable wide speed range output permanent magnet generator system described in this embodiment.

Specific Embodiment 2. This embodiment is a further limitation of the leakage reactance variable wide speed range output permanent magnet generator system described in specific embodiment 1. The leakage reactance variable wide speed range output permanent magnet generator in this embodiment The leakage reactance regulating piece 5 in the machine system is flat-shaped, and the flat leakage reactance regulating piece 5 is located in the radial middle position of the groove where it is located, and divides the groove where it is located into two parts, the axial length of which is less than The distance between the axial ends of the winding in its slot.

Referring to shown in Fig. 2, when n=1, the structural representation of the permanent magnet generator described in the present embodiment, the stator slot number of this permanent magnet generator is 12 slots, and the rotor pole number is 10 poles, so adjacent The electrical angle difference between the two stator slots is 150°, that is (-30°). The winding is a concentrated winding, and each set of winding is composed of 6 coils, and each coil is wound on the armature core teeth 4. Every A tooth is wound around a coil. The 2 turns of the second set of windings are mostly located in the lower layer of the slot, that is, away from the slot side; and the 6 coils embedded in the lower layer of the slot are respectively a1x1, b1y1, c1z1, a2x2, b2y2, c2z2, which are placed in the stator core along the circumference in turn. Arranged on teeth 4, where a1x1 and a2x2 are connected in series, b1y1 and b2y2 are connected in series, c1z1 and c2z2 are connected in series, these 6 coils constitute the second set of windings; the first set of windings has 3 turns and is located on the upper layer of the slot, namely: adjacent to the slot On the side, the six coils are A1X1, B1Y1, C1Z1, A2X2, B2Y2, and C2Z2, which are arranged on the stator core teeth 4 along the circumference in turn, where A1X1 is connected in series with A2X2, B1Y1 is connected in series with B2Y2, and C1Z1 is connected in series with C2Z2. These 6 coils Form the first set of windings.

Specific Embodiment 3. This embodiment is a further limitation of the leakage reactance variable wide speed range output permanent magnet generator system described in specific embodiment 1. The leakage reactance variable wide speed range output permanent magnet generator in this embodiment The leakage reactance regulating piece 5 in the machine system is tile-shaped, and the tile-shaped regulating piece is located in the radial middle position of the groove where it is located, and divides the groove where it is located into two parts, the axial length of which is less than The distance between the axial ends of the winding in its slot.

Specific Embodiment 4. This embodiment is a further limitation of the leakage reactance variable wide speed range output permanent magnet generator system described in specific embodiment 1. The leakage reactance variable wide speed range output permanent magnet generator in this embodiment In the machine system, an axial through slot is opened radially in the middle of the armature teeth, and a thin plate 8 is embedded in the through slot. The thin plate 8 is selected from materials with low resistivity.

Referring to FIG. 3 , it is a schematic structural diagram of the permanent magnet generator described in this embodiment when n=2.

Specific Embodiment 5. This embodiment is a further limitation of the leakage reactance variable wide speed range output permanent magnet generator system described in specific embodiment 1. The leakage reactance variable wide speed range output permanent magnet generator in this embodiment The two sets of three-phase windings in the machine system are star-connected, delta-connected or star-delta mixed.

Specific Embodiment Six. This embodiment is a further limitation of the leakage reactance variable wide speed range output permanent magnet generator system described in specific embodiment one. The leakage reactance variable wide speed range output permanent magnet described in this embodiment The rotor in the generator system is an embedded permanent magnet structure, an external permanent magnet structure or a surface permanent magnet structure.

Specific Embodiment 7. This embodiment is a further limitation of the leakage reactance variable wide speed range output permanent magnet generator system described in specific embodiment 1. The leakage reactance variable wide speed range output permanent magnet described in this embodiment In the generator system, the three-phase rectifier can be an uncontrolled rectifier or a controllable rectifier composed of power semiconductor devices.

For the power semiconductor device described in this embodiment mode, MOSFET or IGBT can be selected.

Claims (8)

1. the variable wide speed range output permanent-magnet generator of leakage reactance system, consisted of by a three-phase permanent synchronous generator and two three-phase rectifiers, described three-phase permanent synchronous generator comprises stator, rotor and air gap, it is characterized in that, described rotor is made of permanent magnet (6), rotor yoke (7) and rotating shaft, and the rotor number of poles is 10n; Described stator is made of (1) unshakable in one's determination and two covers, three phase windings, and the phase difference between described two covers, three phase windings is 30 ° of electrical degrees; The groove number of the described iron core (1) of described stator is 12n, n is positive integer, described two covers, three phase windings are concentrated winding, every cover three phase windings are made of 6n coil, 6n coil in every cover three phase windings distributes along even circumferential and is wrapped on the armature core tooth (4), namely twines a coil every a tooth; The number of turn of double winding is different, the cover winding (2) that the number of turn is many embeds the bottom at groove, the another set of winding that the number of turn is few embeds the upper strata at groove, namely near the notch side, is provided with the leakage reactance adjustment sheet (5) that is made of magnetic material between upper strata winding and the lower floor's winding; The output of every cover three phase windings connects the ac input end of a three-phase rectifier, after the dc output end parallel connection or series connection of two three-phase rectifiers, receives on the common DC bus.

2. the variable wide speed range output permanent-magnet generator of leakage reactance according to claim 1 system, it is characterized in that, described leakage reactance adjustment sheet (5) is plate shaped, this plate shaped leakage reactance adjustment sheet (5) is positioned at the radially centre position of its place groove, and the place groove is divided into inside and outside two parts, the axial length of described adjustment sheet is less than the distance between the axial two ends of the winding in its place groove.

3. the variable wide speed range output permanent-magnet generator of leakage reactance according to claim 1 system, it is characterized in that, described leakage reactance adjustment sheet (5) is tile shape, the adjustment sheet of described tile shape is positioned at the radially centre position of its place groove, and the place groove is divided into inside and outside two parts, the axial length of described adjustment sheet is less than the distance between the axis of winding two ends in its place groove.

4. the variable wide speed range output permanent-magnet generator of leakage reactance according to claim 1 system is characterized in that, radially has axial pass trough in the middle of armature core tooth (4), has embedded thin plate (8) in this groove.

5. the variable wide speed range output permanent-magnet generator of leakage reactance according to claim 1 system is characterized in that, described two covers, three phase windings are that star connection, Y connection, delta connection or star are mixed connection with triangle.

6. the variable wide speed range output permanent-magnet generator of leakage reactance according to claim 1 system is characterized in that, described rotor is embedded permanent magnet (6) structure, extrapolation permanent magnet (6) structure or surperficial permanent magnet (6) structure.

7. the variable wide speed range output permanent-magnet generator of leakage reactance according to claim 1 system is characterized in that, described three-phase rectifier is uncontrollable rectifier.

8. the variable wide speed range output permanent-magnet generator of leakage reactance according to claim 1 system is characterized in that, the controlled rectifier of described three-phase rectifier for being made of power semiconductor.

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