A parallel hybrid excitation synchronous generator

Abstract

The utility model provides a parallel type's mixed excitation synchronous generator, including the rotation axis, the parallel setting has permanent magnet rotor and excitation rotor on rotation axis, is equipped with stator on the outside of permanent magnet rotor and excitation rotor, is equipped with air gap between permanent magnet rotor and stator and between excitation rotor and stator. The utility model solves the technical problem to provide a parallel type's mixed excitation synchronous generator, through possessing the advantage of two kinds of motor, namely high efficiency and adjustable main magnetic flux, reduces excitation machine magnetic field loss, and promotes the efficiency of whole system.

Description

Technical Field

[0001] This utility model relates to the field of generator technology, and in particular to a parallel hybrid excitation synchronous generator. Background Technology

[0002] In a typical hydroelectric power station, electrical energy is generated by the force of falling water. The ability to generate electricity depends on the available flow rate and the head of the dam. Water possesses potential energy at the top of the dam. As the water rushes through the gates and impacts the rotating blades of the turbine through the guide vanes, this potential energy is converted into mechanical energy. The turbine acts as the prime mover of a synchronous generator, generating electrical energy according to Faraday's law of electromagnetic induction. The two main types of synchronous generators are electrically excited synchronous generators and permanent magnet synchronous generators. Using modern rare-earth permanent magnets, the efficiency of permanent magnet synchronous generators can be significantly improved. Permanent magnet synchronous generators do not have an electrically excited system, therefore they are typically highly efficient, compact, and lightweight. The main disadvantage of permanent magnet synchronous generators is the lack of reactive power regulation capability because the main magnetic flux generated by the permanent magnets is not adjustable. The magnetic flux of electrically excited synchronous generators is controllable due to the adjustable excitation windings, but its main disadvantage is relatively high excitation losses.

[0003] Depending on the connection method of the permanent magnet and the electrical excitation power supply, hybrid excitation synchronous generators can be divided into series hybrid excitation synchronous generators and parallel hybrid excitation synchronous generators. In a series hybrid excitation synchronous generator, the two excitation power supplies are connected in series, as shown in Figure 1(a); while in a parallel hybrid excitation synchronous generator, they are connected in parallel, as shown in Figure 1(b). Due to the special properties of rare earth permanent magnets, namely, the permeability of neodymium iron boron permanent magnets is close to that of air, the range of air gap flux variation in a series hybrid excitation synchronous generator is naturally smaller than that in a parallel hybrid excitation synchronous generator. In a parallel hybrid excitation synchronous generator, when the main magnetic flux is enhanced, the air gap flux density can increase by 95%, and when the main magnetic flux is weakened to zero electrical excitation, the air gap flux density can decrease by 70%. On the other hand, in a series hybrid excitation synchronous generator, the air gap flux increases by +17% and decreases by -30% relative to the flux generated solely by the permanent magnet. It can be concluded that if a series hybrid excitation synchronous generator is required to have the same flux variation range as a parallel hybrid excitation synchronous generator, the size of its excitation coil will often be increased, which in turn requires more space to place the excitation winding, thus increasing the size of the generator.

[0004] Depending on the location of the permanent magnets and excitation coils within the motor, the excitation power supply of a hybrid excitation synchronous generator can be arranged in several ways: 1. Both power supplies are in the rotor; 2. Both power supplies are in the stator; 3. One power supply is in the rotor, and one power supply is in the stator; 4. The permanent magnet power supply is installed in the rotor, and the electrical excitation power supply is installed at the motor end. In generator mode, if both power supplies are in the stator, excitation control becomes complex. For the latter two cases, where the excitation power supply is either in the stator or at the motor end, the excitation power supplies of the hybrid excitation synchronous generator are connected in parallel, allowing the main magnetic flux to be adjusted over a wider range. However, this power supply location increases the stator outer diameter of the hybrid excitation synchronous generator. The first case, where both power supplies are in the rotor, allows for series or parallel connection of the two power supplies, and from a manufacturing perspective, this arrangement is much simpler than the others.

[0005] Based on the above considerations, this utility model adopts a parallel hybrid excitation synchronous generator, in which both excitation power sources are placed in the rotor. Summary of the Invention

[0006] The technical problem to be solved by this utility model is to provide a parallel hybrid excitation synchronous generator that combines the advantages of two types of motors, namely high efficiency and adjustable main magnetic flux, thereby reducing the magnetic field loss of the exciter and improving the efficiency of the entire system.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a parallel hybrid excitation synchronous generator, including a rotating shaft, on which a permanent magnet rotor and an excitation rotor are arranged in parallel, a stator is provided on the outside of the permanent magnet rotor and the excitation rotor, and an air gap is provided between the permanent magnet rotor and the stator and between the excitation rotor and the stator.

[0008] Preferably, the permanent magnet rotor is formed by multiple permanent magnet rotor units surrounding each other, and each permanent magnet rotor unit includes a permanent magnet rotor core, within which permanent magnet poles are provided.

[0009] Preferably, the end of the permanent magnet rotor core is provided with a first non-magnetic insulating part, and the permanent magnet poles are provided on both sides inside the first non-magnetic insulating part, and the permanent magnet poles are arranged radially.

[0010] Preferably, the excitation rotor is formed by multiple excitation rotor units surrounding each other, and each excitation rotor unit includes an excitation rotor core, within which excitation poles are provided.

[0011] Preferably, the end of the excitation rotor core is provided with a second non-magnetic insulating part, and the excitation magnetic pole is tangentially disposed in the second non-magnetic insulating part.

[0012] Preferably, an excitation winding is provided between the excitation pole and the second non-magnetic insulating part.

[0013] Preferably, the stator includes a stator core, and a plurality of armature windings are provided inside the stator core.

[0014] Preferably, the core is made of M400-50A silicon steel sheet.

[0015] Preferably, the non-magnetic insulating portion is a thin film of non-magnetic insulating material.

[0016] Preferably, it also includes a frame, with the rotating shaft rotatably connected inside the frame and the stator located on the outside of the frame.

[0017] This utility model provides a parallel hybrid excitation synchronous generator, which has the following advantages: 1. High efficiency: Maintains high efficiency over a wide load range, and reduces electrical excitation losses of permanent magnets at low loads; 2. Flexibility: By adjusting the electric excitation current, the output voltage and reactive power can be flexibly controlled to adapt to different power grid requirements; 3. Stability: Strong anti-interference ability; quickly stabilizes output voltage when the power grid fluctuates or the load changes abruptly. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1(a) shows the series connection of the permanent magnet and the electrically excited power supply; Figure 1(b) shows the parallel connection of the permanent magnet and the electrically excited power supply; Figure 2 This is a schematic diagram of the structure of this utility model; Figure 3 This is a schematic diagram of the permanent magnet rotor unit of this utility model; Figure 4 This is a schematic diagram of the excitation rotor unit of this utility model; Figure 5 This is a schematic diagram of the excitation coil of this utility model. Detailed Implementation

[0019] like Figure 2 As shown, a parallel hybrid excitation synchronous generator includes a rotating shaft 1, on which a permanent magnet rotor 2 and an excitation rotor 3 are arranged in parallel. A stator 4 is provided on the outside of the permanent magnet rotor 2 and the excitation rotor 3. An air gap 5 is provided between the permanent magnet rotor 2 and the stator 4 and between the excitation rotor 3 and the stator.

[0020] Preferred, such as Figure 3 As shown, the permanent magnet rotor 2 is composed of multiple permanent magnet rotor units, each of which includes a permanent magnet rotor core 6, and a permanent magnet pole 7 is provided inside the permanent magnet rotor core 6.

[0021] Preferably, the permanent magnet rotor core 6 has a first non-magnetic insulating portion 8 at its end, and permanent magnet poles 7 are disposed on both sides inside the first non-magnetic insulating portion 8, arranged radially. The first non-magnetic insulating portion 8 is used for coil winding insulation and has the characteristics of high temperature resistance and aging resistance.

[0022] Preferred, such as Figure 4 As shown, the excitation rotor 3 is composed of multiple excitation rotor units, each of which includes an excitation rotor core 9, and an excitation pole 10 is provided inside the excitation rotor core 9.

[0023] Preferably, the end of the excitation rotor core 9 is provided with a second non-magnetic insulating part 11, and the excitation magnetic pole 10 is tangentially disposed within the second non-magnetic insulating part 11. The second non-magnetic insulating part 11 is used for coil winding insulation and has the characteristics of high temperature resistance and aging resistance.

[0024] Preferred, such as Figure 5 As shown, an excitation winding 12 is provided between the excitation pole 10 and the second non-magnetic insulating part 11.

[0025] Preferably, the stator 4 includes a stator core 13, and a plurality of armature windings 14 are provided inside the stator core.

[0026] Preferably, the core is made of M400-50A silicon steel sheet.

[0027] Preferably, the non-magnetic insulating film is made of a non-magnetic insulating material. Examples include polyester film and polytetrafluoroethylene film.

[0028] Preferably, it also includes a frame 15, with the rotating shaft 1 rotatably connected inside the frame 15, and the stator 4 located on the outside of the frame 15.

[0029] The hybrid excitation synchronous generator has two rotor sections that share a single stator, and the stator currents of the two rotors are the same. The total power of the hybrid excitation synchronous generator is the sum of the power generated by the permanent magnet rotor section and the electrically excited rotor section; the d-axis synchronous inductance Ld is the sum of the Ld of the permanent magnet rotor section and the Ld of the electrically excited rotor section.

[0030] Since the two rotors in the hybrid excitation synchronous generator are placed side by side, two rotors are designed separately and then the results are combined. Figure 3 The image shows a cross-sectional view of a single magnetic pole of the permanent magnet rotor section of the design. Figure 4 A cross-sectional view of a single magnetic pole of the electrically excited rotor section of the design is shown.

[0031] Hybrid excitation synchronous generators combine the advantages of permanent magnet synchronous motors, namely the physical properties of rare earth permanent magnet materials, with the advantages of electrically excited synchronous motors, namely the ability to adjust the main magnetic flux through excitation coils. In this type of motor, the permanent magnet is only used to generate the main magnetic flux of the motor, while the excitation coil is used to enhance or weaken the main magnetic flux. Through this combination, hybrid excitation synchronous generators have lower electrical excitation losses compared to electrically excited synchronous motors.

[0032] The above embodiments are merely preferred technical solutions of this utility model and should not be considered as limitations on this utility model. The protection scope of this utility model should be the technical solution described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the protection scope of this utility model.

Claims

1. A parallel hybrid excitation synchronous generator comprising a rotating shaft (1), characterized in that: A permanent magnet rotor (2) and an excitation rotor (3) are arranged side by side on a rotating shaft (1). A stator (4) is provided on the outside of the permanent magnet rotor (2) and the excitation rotor (3). An air gap (5) is provided between the permanent magnet rotor (2) and the stator (4) and between the excitation rotor (3) and the stator.

2. The parallel hybrid excitation synchronous generator according to claim 1, characterized in that: The permanent magnet rotor (2) is formed by multiple permanent magnet rotor units, each of which includes a permanent magnet rotor core (6) and a permanent magnet pole (7) is provided inside the permanent magnet rotor core (6).

3. The parallel hybrid excitation synchronous generator according to claim 2, characterized in that: The end of the permanent magnet rotor core (6) is provided with a first non-magnetic insulating part (8), and permanent magnet poles (7) are provided on both sides inside the first non-magnetic insulating part (8), and the permanent magnet poles (7) are arranged radially.

4. The parallel hybrid excitation synchronous generator according to claim 1, characterized in that: The excitation rotor (3) is formed by multiple excitation rotor units, each of which includes an excitation rotor core (9) and an excitation pole (10) is provided inside the excitation rotor core (9).

5. The parallel hybrid excitation synchronous generator according to claim 4, characterized in that: The end of the excitation rotor core (9) is provided with a second non-magnetic insulating part (11), and the excitation magnetic pole (10) is arranged tangentially in the second non-magnetic insulating part (11).

6. The parallel hybrid excitation synchronous generator according to claim 5, characterized in that: An excitation winding (12) is provided between the excitation pole (10) and the second non-magnetic insulating part (11).

7. The parallel hybrid excitation synchronous generator according to claim 1, characterized in that: The stator (4) includes a stator core (13) and multiple armature windings (14) are provided inside the stator core.

8. A parallel hybrid excitation synchronous generator according to any one of claims 2-7, characterized in that: The iron core is made of M400-50A silicon steel sheets.

9. The parallel hybrid excitation synchronous generator according to claim 3 or 5, characterized in that: The non-magnetic insulating part uses a thin-film non-magnetic insulating material.

10. The parallel hybrid excitation synchronous generator according to claim 1, characterized in that: It also includes a frame (15), a rotating shaft (1) rotatably connected inside the frame (15), and a stator (4) located on the outside of the frame (15).

Images