A kind of AC-DC hybrid power generation power supply system of double-stator axial flux generator

Abstract

The application relates to a kind of AC-DC hybrid power generation power supply system of double-stator axial flux generator, the system includes generator unit and rectifier unit, the generator unit is double-stator axial flux permanent magnet generator, the DC winding unit of DC side stator and rectifier unit connection constitutes DC power supply, for generating DC voltage;The AC winding unit of AC side stator is used to generate AC voltage.The application can provide AC and DC power supply simultaneously by a generator;AC and DC power supply are not coupled in electricity and machinery;The voltage pulsation coefficient of DC power supply is low;The eddy current loss of generator rotor is small;AC and DC power supply have redundancy fault-tolerant operation ability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power generation and power supply, in particular to an axial flux permanent magnet generator for AC-DC hybrid power generation and power supply. BACKGROUND

[0002] In independent systems such as aircraft, ships, space stations, spacecraft, and oil drilling platforms, both AC power and DC power are often required, and the quality of DC power supply is often required to be high, and the size and weight of the AC-DC hybrid power generation and power supply system are strictly limited.

[0003] To obtain AC and DC power at the same time, patent (application number CN201610258892.4) proposes a dual-winding asynchronous motor AC-DC starting power generation system for a more electric aircraft and a control method thereof. The system has two dual-winding asynchronous generators, each connected to a different prime mover shaft. One outputs AC power, and the other outputs DC power after rectification. This scheme realizes the supply of AC and DC power for a more electric aircraft, but the system structure and control strategy are complex, and the use of two motors increases the size and weight of the entire system. Patent (application number CN201811114730.9) proposes a topology structure and control method of an AC-DC generator system. Two sets of stator windings are placed on one generator. One set of three-phase Y-connected windings directly outputs three-phase AC power, and the other set of windings is an open winding structure. Each end of the winding is connected to a power generation and driving unit. The outputs of the two power generation and driving units are connected in series and output DC power. This system can provide AC and DC power at the same time, but the DC side topology structure is complex, and the AC winding and DC winding are mechanically coupled, which reduces the reliability of the system.

[0004] Therefore, it is particularly necessary to design an AC-DC hybrid power generation system that is relatively simple in structure, small in size, and high in reliability. SUMMARY

[0005] OBJECTIVE

[0006] The present application proposes an AC-DC hybrid power generation and power supply system for a dual-stator axial flux generator, which aims to provide an AC-DC hybrid power generation and power supply system that is small in size, light in weight, simple in structure, high in power density, and can provide AC and DC power at the same time. The system eliminates the electrical or mechanical coupling between the AC power source and the DC power source in traditional AC-DC hybrid power generation systems, improves the redundancy and fault tolerance operation capability of the system, reduces the voltage ripple coefficient of the DC power source, and improves the power supply quality.

[0007] TECHNICAL SCHEME

[0008] An AC-DC hybrid power generation and supply system of a double-stator axial flux generator, the system comprising a generator unit and a rectifier unit, the generator unit being a double-stator axial flux permanent magnet generator, the DC side stator and the AC side stator of the generator unit being symmetrically fixed in a machine base, the rotor of the generator unit being fixed on a rotating shaft, the DC side stator and the AC side stator being symmetrically placed on both sides of the rotor, there being air gaps between the DC side stator and the AC side stator and the rotor, the DC winding unit of the DC side stator and the rectifier unit being connected to form a DC power supply for generating a DC voltage; the AC winding unit of the AC side stator being used for generating an AC voltage.

[0009] Further, the DC winding unit is composed of n groups of j-phase symmetric windings, n and j being natural numbers, the n groups of j-phase symmetric windings in the DC winding unit being respectively connected to n groups of j-phase full-wave rectifier bridges of the rectifier unit, when n > 1, n n groups j of the symmetric windings are sequentially different by θ = 180° / e electrical degrees in space; the AC winding unit is composed of jn groups m of symmetric windings, k , m k n and j being natural numbers, when n > 1, m m groups k of the symmetric windings are sequentially different by θ = 180° / e electrical degrees in space. β km

[0010] Further, the DC side stator comprises a DC stator core and a DC winding unit, and the AC side stator comprises an AC stator core and an AC winding unit; the DC stator core and the AC stator core each comprise armature teeth and armature slots, the DC winding unit is embedded in the armature slots in the DC stator core, and the AC winding unit is embedded in the armature slots in the AC stator core.

[0011] Further, the rotor comprises a rotor frame and permanent magnets; two permanent magnet mounting holes are formed on the rotor frame, the permanent magnets are embedded in the permanent magnet mounting holes, the magnetization directions F of the adjacent two permanent magnets are different, and a pair of poles is formed on the rotor; the rotor frame is made of non-magnetic material. p p

[0012] Further, the voltage ripple coefficient of the DC power supply is S n = 2 / ((2 nj ) 2 - 1).

[0013] A control method of an AC-DC hybrid power generation and supply system of a double-stator axial flux generator, when one group of the DC winding unit j ​​​​​​​A set of phase symmetrical windings or rectification units j When the phase full-wave rectification bridge fails, the system cuts off the set j Phase symmetrical windings and corresponding j Phase full-wave rectification bridge, DC power supply load operation; when the AC winding unit in m Set k A set of phase symmetrical windings k When the phase symmetrical winding fails, the system cuts off the set k Phase symmetrical winding.

[0014] The present application has the following technical effects relative to the prior art:

[0015] (1) The AC / DC hybrid power generation and power supply system of the double-stator axial flux generator proposed in the present application has higher reliability and redundant fault-tolerant operation capability.

[0016] (2) The AC / DC hybrid power generation and power supply system of the double-stator axial flux generator proposed in the present application has the advantages of small size and light weight compared to the AC / DC hybrid power generation and power supply system of the traditional AC / DC generator set.

[0017] (3) The AC / DC hybrid power generation and power supply system of the double-stator axial flux generator proposed in the present application has higher power density compared to the AC / DC hybrid power supply system of the traditional multi-winding AC / DC generator.

[0018] (4) The AC / DC hybrid power generation and power supply system of the double-stator axial flux generator proposed in the present application has simple rectification unit structure and low voltage pulsation coefficient of the DC power supply. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced as follows.

[0020] Figure 1 It is a schematic diagram of the AC / DC hybrid power generation and power supply system of the present application;

[0021] Figure 2 It is a sectional view of the generator unit of the AC / DC hybrid power generation and power supply system of the present application;

[0022] Figure 3 It is a DC side or AC side stator diagram of the generator unit of the AC / DC hybrid power generation and power supply system of the present application;

[0023] Figure 4 It is a rotor structure diagram of the generator unit of the AC / DC hybrid power generation and power supply system of the present application;

[0024] Figure 5 DC voltage ripple for three-phase and six-phase electric machines.

[0025] Wherein: 1 - generator unit, 10 - DC side stator, 100 - DC winding unit, 101 - first DC j phase winding, 102 - second DC j phase winding, 10n - nth DC j phase winding, 11A - second air gap, 11D - first air gap, 12 - rotor, 121 - rotor frame, 122 - permanent magnet, 1211 - permanent magnet mounting hole, 13 - machine base, 14 - rotating shaft, 15 - bearing, 2 - rectifier unit, 20 - AC side stator, 200 - AC winding unit, 201 - first AC k phase winding, 202 - second AC k phase winding, 20m - mth AC k phase winding, 3 - DC power supply, 300A - AC stator core, 300D - DC stator core, 301 - armature tooth, 302 - armature slot. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

[0027] As shown in Figure 1 and 2 , the present example provides a DC / AC hybrid power generation and power supply system based on a double-stator axial flux permanent magnet generator, which comprises a generator unit 1 and a rectifier unit 2; the generator unit 1 is a double-stator axial flux permanent magnet generator, and the generator unit 1 comprises a fixed body and a rotating body, the fixed body and the rotating body are connected through a bearing 15, the fixed body comprises a DC side stator 10, an AC side stator 20 and a machine base 13, the DC side stator 10 and the AC side stator 20 are symmetrically fixed in the machine base 13, specifically, the DC side stator 10 and the AC side stator 20 are respectively fixed on different machine bases 13; the rotating body comprises a rotor 12 and a rotating shaft 14, the rotor 12 is fixed on the rotating shaft 14, the DC side stator 10 and the AC side stator 20 are symmetrically placed on both sides of the rotor 12, and there are air gaps 11 between the DC side stator 10 and the AC side stator 20 and the rotor 12, the air gaps 11 are two, which are a first air gap 11D and a second air gap 11A, the first air gap 11D exists between the DC side stator 10 and the rotor 12, and the second air gap 11A exists between the AC side stator 20 and the rotor 12. The DC winding unit 100 of the DC side stator 10 and the rectifier unit 2 are connected to form a DC power supply 3 for generating a DC voltage; the DC winding unit 100 is composed of n groups j of symmetrical windings, n, j These are natural numbers, respectively called the first DC. j Phase winding 101, second DC j Phase windings 102, ..., ... n DC j Phase winding 10 n DC winding unit 100 n Group j The symmetrical windings are respectively connected to rectifier unit 2. n Group j The full-wave rectifier bridge uses AC winding units 200 on the AC side stator 20 to generate AC voltage. The DC winding unit and AC winding unit can be designed with different numbers of phases depending on the application, and the two units are mounted on a separate stator, with no electrical or mechanical coupling.

[0028] When DC winding unit 100 n When >1, n Group j The symmetrical windings are spatially separated by θ = 180°. jn Electrical angle; AC winding unit 200 m Group k Symmetrical winding configuration, m , k For natural numbers, they are respectively called the first exchange. k Phase winding 201, second AC k Phase winding 202, ..., No. m comminicate k Phase winding 10 m ,when m When >1, m Group k The symmetrical windings are spatially spaced in sequence. β =180° / km Electrical angle (i.e., first AC) k Phase winding 201 and the second AC k Phase difference of phase winding 202 β =180° / km Electrical angle, up to the first m -1 Exchange k Phase winding 20 ( m -1) and the m comminicate k Phase winding 20 m difference β =180° / km (electric angle).

[0029] like Figure 3As shown, the DC-side stator 10 in the generator unit 1 includes a DC stator core 300D and a DC winding unit 100, and the AC-side stator 20 includes an AC stator core 300A and an AC winding unit 200. Both the DC stator core 300D and the AC stator core 300A include armature teeth 301 and armature slots 302. The DC winding unit 100 is embedded in the armature slot 302 in the DC stator core 300D, and the AC winding unit 200 is embedded in the armature slot 302 in the AC stator core 300A.

[0030] like Figure 4 As shown, the rotor 12 in the generator unit 1 includes a rotor frame 121 and a permanent magnet 122; two openings are formed on the rotor frame 121. p A permanent magnet mounting hole 1211 is provided, and a permanent magnet 122 is embedded in the permanent magnet mounting hole 1211. The magnetization directions F of two adjacent permanent magnets 122 are opposite, thus constructing a permanent magnet mounting hole 1211 on the rotor 12. p Opposite pole; rotor frame 121 is made of non-magnetic material.

[0031] like Figure 1 As shown, the DC winding unit 100 in the generator unit 1 is composed of... n Group three phases ( Figure 1 In j =3) Symmetrical winding configuration, n These are natural numbers, respectively named the first DC three-phase winding 101, the second DC three-phase winding 102, ..., the ... n DC three-phase winding 10 n ,when n When >1, n The three-phase symmetrical windings are spatially spaced with a phase difference of θ = 180° / 3. n Electrical angle (i.e., the phase difference between the first DC three-phase winding 101 and the second DC three-phase winding 102) θ = 180° / 3 n Electrical angle, up to the first n -1 DC three-phase winding 10 ( n -1) and the n DC three-phase winding 10 n Phase difference θ = 180° / 3 n Electrical angle). Selected n The larger the value, the smaller the DC voltage ripple coefficient, and the stronger the power supply's redundancy and fault tolerance capability. Figure 5 A simulation was performed on a motor with n=m=2 and j=k=3. The number of DC ripples generated per pair of magnetic poles rotated by the motor is 2. jn =2×3×2=12 times, Figure 5 The simulation passed through two pairs of magnetic poles, so the number of voltage fluctuations was 24. Figure 5 The peak-to-peak voltage fluctuation in the system decreased from 37.20V in the three-phase system to 11.07V in the six-phase system.

[0032] As Figure 1 shown, the AC winding unit 200 in the generator unit 1 is composed of m three-phase symmetrical windings, Figure 1 k =3), m is a natural number, respectively referred to as a first AC three-phase winding 201, a second AC three-phase winding 202, …, and a m AC three-phase winding 10 m When m >1, m the three-phase symmetrical windings are sequentially different by β =180° / 3 m electrical angle (i.e., the first AC three-phase winding 201 is different from the second AC three-phase winding 202 by β =180° / 3 m electrical angle, and so on until the m -1 AC three-phase winding 20 m -1) is different from the m AC three-phase winding 20 m by β =180° / 3 m electrical angle). Increasing the value of m can reduce the armature reaction air gap magnetic field harmonic distortion rate, and further reduce the rotor eddy current loss of the generator.

[0033] The n three-phase symmetrical windings in the DC winding unit 100 are respectively connected to n three-phase full-wave rectifier bridges, when one of the three-phase symmetrical windings (or one of the three-phase full-wave rectifier bridges) fails, the system cuts off the three-phase symmetrical winding and the three-phase full-wave rectifier bridge corresponding thereto, and the DC power supply 3 runs in a reduced load state; when one of the m three-phase symmetrical windings in the AC winding unit 200 fails, the system cuts off the three-phase symmetrical winding.

[0034] The application provides an AC-DC hybrid power generation and supply system based on a double-stator axial flux permanent magnet generator, which can reduce the volume and weight of the AC-DC hybrid power generation system, has a simple structure, and is free of electrical and mechanical coupling between the AC winding unit and the DC winding unit. The smaller the DC voltage pulsation coefficient is, the better the redundant fault-tolerant operation capability is.​

Claims

1. A hybrid AC / DC power generation system for a dual-stator axial flux generator, characterized in that: The system includes a generator unit (1) and a rectifier unit (2). The generator unit (1) is a dual-stator axial flux permanent magnet generator. The DC-side stator (10) and AC-side stator (20) of the generator unit (1) are symmetrically fixed in the frame (13). The rotor (12) of the generator unit (1) is fixed on the shaft (14). The DC-side stator (10) and AC-side stator (20) are symmetrically placed on both sides of the rotor (12). There is an air gap (11) between the DC-side stator (10) and the AC-side stator (20) and the rotor (12). The DC winding unit (100) of the DC-side stator (10) and the rectifier unit (2) are connected to form a DC power supply (3) for generating DC voltage. The AC winding unit (200) of the AC-side stator (20) is used to generate AC voltage. The DC winding unit (100) is composed of n sets of j-phase symmetrical windings, where n and j are natural numbers. The n sets of j-phase symmetrical windings in the DC winding unit (100) are respectively connected to the n sets of j-phase full-wave rectifier bridges of the rectifier unit (2). When n>1 in the DC winding unit (100), the n sets of j-phase symmetrical windings are spatially separated by θ=180° / jn electrical angles. The AC winding unit (200) is composed of m sets of k-phase symmetrical windings, where m and k are natural numbers. When m>1, the m sets of k-phase symmetrical windings are spatially separated by β=180° / km electrical angles. The voltage ripple coefficient of the DC power supply (3) is Sn=2 / ((2nj)2-1); When a set of j-phase symmetrical windings in the DC winding unit (100) or a set of j-phase full-wave rectifier bridges in the rectifier unit (2) fails, the system disconnects the set of j-phase symmetrical windings and the corresponding j-phase full-wave rectifier bridges, and the DC power supply (3) operates at reduced load; when a set of k-phase symmetrical windings in the m sets of k-phase symmetrical windings in the AC winding unit (200) fails, the system disconnects the set of k-phase symmetrical windings.

2. The AC / DC hybrid power generation and supply system of a dual-stator axial flux generator according to claim 1, characterized in that: The DC-side stator (10) includes a DC stator core (300D) and a DC winding unit (100), and the AC-side stator (20) includes an AC stator core (300A) and an AC winding unit (200). Both the DC stator core (300D) and the AC stator core (300A) include armature teeth (301) and armature slots (302). The DC winding unit (100) is embedded in the armature slot (302) of the DC stator core (300D), and the AC winding unit (200) is embedded in the armature slot (302) of the AC stator core (300A).

3. The AC / DC hybrid power generation and supply system of a dual-stator axial flux generator according to claim 1, characterized in that: The rotor (12) includes a rotor frame (121) and permanent magnets (122); 2p permanent magnet mounting holes (1211) are opened on the rotor frame (121), and the permanent magnets (122) are embedded in the permanent magnet mounting holes (1211). The magnetization directions F of two adjacent permanent magnets (122) are opposite, and p pole pairs are constructed on the rotor (12); the rotor frame (121) is made of non-magnetic material.

4. A control method for an AC / DC hybrid power generation and supply system of a dual-stator axial flux generator as described in claim 1, characterized in that: When a set of j-phase symmetrical windings in the DC winding unit (100) or a set of j-phase full-wave rectifier bridges in the rectifier unit (2) fails, the system disconnects the set of j-phase symmetrical windings and the corresponding j-phase full-wave rectifier bridges, and the DC power supply (3) operates at reduced load; when a set of k-phase symmetrical windings in the m sets of k-phase symmetrical windings in the AC winding unit (200) fails, the system disconnects the set of k-phase symmetrical windings.

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