阅读说明：本技术 一种发电机自并励无刷励磁系统及其应用 (Self-shunt excitation brushless excitation system of generator and application thereof ) 是由 王丹 毛承雄 张甜甜 官志涛 谷博 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种发电机自并励无刷励磁系统及其应用,属于发电机励磁控制领域,包括：励磁变压器,其高压侧与发电机的机端相连；三相整流器,其交流侧与励磁变压器的低压侧相连；P路高频交流发生器,各输入端均与三相整流器的输出端相连；M对沿圆周排列的固定磁极,与P路高频交流发生器的输出端相连；N对沿圆周排列的旋转磁极,与发电机的转子同轴转动,与M对固定磁极形成电磁感应,实现能量传输；两圆周同心；N个与发电机的转子同轴转动的单相整流器,分别与N对旋转磁极串联,形成N条支路,N条支路通过并联和/或串联后与发电机的励磁绕组串联,为发电机提供励磁。本发明能够实现自并励无刷励磁,提高系统可靠性并减少维护成本。(The invention discloses a self-shunt excitation brushless excitation system of a generator and application thereof, belonging to the field of excitation control of the generator and comprising the following steps: the high-voltage side of the excitation transformer is connected with the generator end of the generator; the alternating current side of the three-phase rectifier is connected with the low-voltage side of the excitation transformer; the P-path high-frequency alternating current generator is connected with the output end of the three-phase rectifier at each input end; m pairs of fixed magnetic poles arranged along the circumference are connected with the output end of the P-path high-frequency alternating current generator; n pairs of rotating magnetic poles which are arranged along the circumference rotate coaxially with the rotor of the generator to form electromagnetic induction with M pairs of fixed magnetic poles, so that energy transmission is realized; the two circumferences are concentric; the N single-phase rectifiers which rotate coaxially with the rotor of the generator are respectively connected with the N rotating magnetic poles in series to form N branches, and the N branches are connected with the excitation winding of the generator in series after being connected in parallel and/or in series to provide excitation for the generator. The invention can realize self-shunt brushless excitation, improve the system reliability and reduce the maintenance cost.)

1. A self shunt excitation brushless excitation system for a generator, comprising:

the high-voltage side of the excitation transformer is connected with the generator end of the generator and is used for carrying out voltage reduction treatment on the generator end alternating-current voltage of the generator;

the alternating current side of the three-phase rectifier is connected with the low-voltage side of the excitation transformer and is used for rectifying the alternating voltage output by the excitation transformer into direct-current voltage;

the input end of each high-frequency alternating current generator is connected with the output end of the three-phase rectifier and used for converting the direct-current voltage output by the three-phase rectifier into P high-frequency alternating-current voltage with controllable phase difference;

m pairs of fixed magnetic poles arranged along the first circumference are connected with the output end of the P-path high-frequency alternating current generator, a plurality of pairs of fixed magnetic poles connected to the same path of high-frequency alternating current generator are mutually connected in parallel, and the high-frequency alternating current voltage output by the P-path high-frequency alternating current generator supplies power;

n pairs of rotating magnetic poles arranged along a second circumference and rotating coaxially with a rotor of the generator; the N pairs of rotating magnetic poles are used for inducing alternating current voltage on each pair of rotating magnetic poles through electromagnetic induction between the N pairs of rotating magnetic poles and the M pairs of fixed magnetic poles; the first circumference is concentric with the second circumference;

the N single-phase rectifiers are coaxially rotated with the rotor of the generator and are respectively connected with the N pairs of rotating magnetic poles in series to form N branches, and each single-phase rectifier is used for rectifying alternating current voltage output by the pair of rotating magnetic poles connected with the single-phase rectifier in series into direct current voltage; the N branches are connected in parallel and/or in series and then are connected in series with an excitation winding of the generator to provide excitation for the generator;

wherein M, N and P are both preset positive integers.

2. The generator self-shunt brushless excitation system of claim 1, wherein in each pair of fixed poles, one pole is excited in a forward direction and the other pole is excited in a reverse direction;

in the M pairs of fixed magnetic poles, the forward excitation magnetic poles and the reverse excitation magnetic poles are arranged at intervals in a crossed manner, or the forward excitation magnetic poles and the reverse excitation magnetic poles are symmetrically arranged about the diameter of the first circumference.

3. The generator self-shunt brushless excitation system of claim 2, wherein the M pairs of fixed poles have the forward excited poles and the reverse excited poles alternately arranged, and the excitation direction of each fixed pole is fixed during operation.

4. The generator self-shunt brushless excitation system of claim 1, wherein in each pair of fixed poles, one pole is excited in a forward direction and the other pole is excited in a reverse direction;

the M pairs of fixed magnetic poles are arranged without gaps, in the working process, the excitation direction of each rotary magnetic pole after induction is fixed, and the excitation direction of each rotary magnetic pole is the same as that of the fixed magnetic pole opposite to the rotary magnetic pole.

5. The generator self-shunt excitation brushless excitation system according to any one of claims 1 to 4, wherein the three-phase rectifier is a two-level, three-level or multilevel structure based on thyristors of half-controlled devices, or the three-phase rectifier is a two-level, three-level or multilevel structure based on fully-controlled devices.

6. The generator self-shunt excitation brushless excitation system according to any one of claims 1 to 4, wherein the single-phase rectifier is a diode-based rectifier, a fully-controlled device-based rectifier, or a diode-based rectifier in series with a current-sharing resistor.

7. Generator self-shunt excitation brushless excitation system according to any of claims 1 to 4, wherein the high frequency AC generator is a chopper.

8. An electrical generator system, comprising: a generator and a generator self shunt excitation brushless excitation system as claimed in any one of claims 1 to 7.

Technical Field

The invention belongs to the field of generator excitation control, and particularly relates to a self-shunt excitation brushless excitation system of a generator and application thereof.

Background

The excitation system is an important component of the synchronous generator, has an important function for maintaining the stable operation of the generator, can maintain the generator terminal voltage, realizes the reasonable distribution of the reactive power among the generators in parallel operation, and can improve the stability of the power system. The selection of a proper excitation mode plays an important role in ensuring the performance of an excitation system.

At present, a self-shunt excitation mode is mostly adopted for a synchronous generator, an excitation power supply of the synchronous generator is taken from the end of the generator and is supplied to the generator for excitation through an excitation transformer and a silicon controlled rectifier, the excitation response time is short, the regulation speed of the end voltage of the generator is high, and the capability of improving the stability of a system is outstanding. However, the self-shunt excitation system needs the carbon brush and the slip ring to transmit the current of a static rotating part and a rotating part, the carbon brush and the slip ring are easy to have mechanical faults and need to be maintained, the carbon powder and the copper powder are easy to cause the pollution of a motor winding and influence the insulation, and when flammable gas exists in the surrounding environment, the spark generated between the slip ring and the carbon brush is easy to cause accidents; in addition, when the self-shunt excitation system generates a three-phase short circuit at the near end of the generator, the strong excitation capacity is obviously reduced. The three-machine brushless excitation system is another common excitation mode, the system is a separately excited brushless excitation system, an excitation power supply is not affected by terminal voltage drop, and a carbon brush and a slip ring are not arranged, but the three-machine brushless excitation system needs a coaxial exciter, the length of a machine set is large, an exciter link is added in the middle of the excitation system, the response speed is low, the failure rate is increased, the shafting is long, and the risk of machine set vibration and torsional vibration is increased.

Generally, the self-shunt excitation system has obvious engineering advantages, but because the carbon brush and the slip ring exist, mechanical faults are easy to occur, the pollution of a motor winding is easy to cause, accidents are easy to cause, regular maintenance is required, and the self-shunt excitation system is difficult to be applied to occasions such as small and medium explosion-proof motors.

Disclosure of Invention

Aiming at the defects and improvement requirements of the prior art, the invention provides a self-shunt excitation brushless excitation system of a generator and application thereof, aiming at realizing energy transmission and brushless excitation through electromagnetic induction, thereby eliminating a slip ring and a carbon brush in a conventional self-shunt excitation system and improving the operation reliability of the system.

To achieve the above object, according to one aspect of the present invention, there is provided a self-shunt excitation brushless excitation system for a generator, comprising:

the high-voltage side of the excitation transformer is connected with the generator end of the generator and is used for carrying out voltage reduction treatment on the generator end alternating-current voltage of the generator;

the three-phase rectifier is connected with the low-voltage side of the excitation transformer on the alternating current side and used for rectifying the alternating voltage output by the excitation transformer into direct-current voltage;

the input end of each high-frequency alternating current generator is connected with the output end of the three-phase rectifier and used for converting the direct-current voltage output by the three-phase rectifier into P high-frequency alternating-current voltage with controllable phase difference;

m pairs of fixed magnetic poles arranged along the first circumference are connected with the output end of the P-path high-frequency alternating current generator, a plurality of pairs of fixed magnetic poles connected to the same path of high-frequency alternating current generator are mutually connected in parallel, and the high-frequency alternating current voltage output by the P-path high-frequency alternating current generator supplies power; the M pairs of fixed magnetic poles are arranged along a first circumference;

n pairs of rotating magnetic poles arranged along a second circumference, coaxially rotate with a rotor of the generator and are arranged along a second circumference concentric with the first circumference; the N pairs of rotating magnetic poles are used for inducing alternating current voltage on each pair of rotating magnetic poles through electromagnetic induction between the N pairs of fixed magnetic poles and the M pairs of fixed magnetic poles; the first circumference is concentric with the second circumference;

the N single-phase rectifiers rotate coaxially with the rotor of the generator and are respectively connected with the N pairs of rotating magnetic poles in series to form N branches, and each single-phase rectifier is used for rectifying alternating current voltage output by the pair of rotating magnetic poles connected with the single-phase rectifier in series into direct current voltage; the N branches are connected in parallel and/or in series and then are connected in series with an excitation winding of the generator to provide excitation for the generator;

wherein M, N and P are both preset positive integers.

The self-shunt excitation brushless excitation system of the generator is supplied with power by the generator terminal voltage to provide excitation for the generator, so that a self-shunt excitation mode is realized; on the basis, in the excitation system provided by the invention, the N rotating magnetic poles rotating coaxially with the generator rotor and the N single-phase rectifiers form a rotating part, the rotating part realizes energy transmission through electromagnetic induction between the rotating magnetic poles and the fixed magnetic poles and supplies power for the excitation winding of the generator, so that a carbon brush and a slip ring are omitted, the technical problems that mechanical faults are easy to occur, motor winding pollution is easy to cause and accidents are easy to occur in the traditional self-shunt excitation system due to the use of the carbon brush and the slip ring are effectively solved while self-shunt excitation is realized, the system operation reliability is effectively improved, and the maintenance cost is reduced.

In some alternative embodiments, one pole of each fixed pair is forward-excited and the other pole is reverse-excited;

in the M pairs of fixed magnetic poles, the forward excited magnetic poles and the reverse excited magnetic poles are arranged at intervals, or the forward excited magnetic poles and the reverse excited magnetic poles are arranged symmetrically about the diameter of the first circumference.

In some alternative embodiments, the M pairs of fixed magnetic poles are arranged with the forward-excited magnetic pole and the reverse-excited magnetic pole crossed and spaced, and the excitation direction of each fixed magnetic pole is fixed during operation.

In the invention, the magnetic poles excited in the positive direction and the magnetic poles excited in the negative direction are arranged in the M pairs of fixed magnetic poles at intervals in a crossed manner, and the excitation directions in the fixed magnetic poles are fixed and unchanged in the working process, so that the control mode is easy to realize, and the fixed magnetic poles and the rotary magnetic poles are arranged at equal intervals, thereby saving the cost.

In some alternative embodiments, one pole of each fixed pair is forward-excited and the other pole is reverse-excited;

the M pairs of fixed magnetic poles are arranged without gaps, in the working process, the excitation direction of each rotary magnetic pole after induction is fixed, and the excitation direction of each rotary magnetic pole is the same as that of the fixed magnetic pole opposite to the rotary magnetic pole.

The invention can provide higher energy transmission efficiency by arranging the M pairs of fixed magnetic poles without gaps, fixing the excitation direction of the rotary magnetic poles at each appointed position in the working process, and ensuring that the excitation directions of the rotary magnetic poles and the fixed magnetic poles opposite to the rotary magnetic poles are the same.

In some optional embodiments, the three-phase rectifier is a two-level structure, a three-level structure or a multi-level structure based on a thyristor of a half-controlled device, or the three-phase rectifier is a two-level structure, a three-level structure or a multi-level structure based on a full-controlled device.

In some optional embodiments, the single-phase rectifier is a diode-based rectifier, a fully-controlled device-based rectifier, or a diode-based rectifier connected in series with a current-sharing resistor.

In some alternative embodiments, the high frequency ac generator is a chopper.

According to another aspect of the present invention, there is provided a generator system comprising: the invention provides a generator and a self-shunt excitation brushless excitation system of the generator.

Based on the characteristic that the self-shunt excitation brushless excitation system of the generator provided by the invention can effectively improve the operation reliability of the system, the generator system provided by the invention has higher operation reliability.

Generally, by the above technical solution conceived by the present invention, the following beneficial effects can be obtained:

(1) the self-shunt excitation brushless excitation system of the generator is supplied with power by the generator terminal voltage to provide excitation for the generator, so that a self-shunt excitation mode is realized; on the basis, in the excitation system provided by the invention, the N rotating magnetic poles rotating coaxially with the generator rotor and the N single-phase rectifiers form a rotating part, the rotating part realizes energy transmission through electromagnetic induction between the rotating magnetic poles and the fixed magnetic poles and supplies power for the excitation winding of the generator, so that a carbon brush and a slip ring are omitted, the technical problems that mechanical faults are easy to occur, motor winding pollution is easy to cause and accidents are easy to occur in the traditional self-shunt excitation system due to the use of the carbon brush and the slip ring are effectively solved while self-shunt excitation is realized, the system operation reliability is effectively improved, and the maintenance cost is reduced.

(2) The self-shunt excitation brushless excitation system of the generator, provided by the invention, has the advantages that the rotating part comprises a plurality of branches formed by connecting the rotating magnetic pole pairs and the single-phase rectifier in series, each branch forms an energy transmission channel, when a single rotating transmission channel fails, the system can still supply power continuously, the redundancy of the system is improved, and the operation reliability of equipment is further improved.

(3) According to the self-shunt excitation brushless excitation system of the generator, high-frequency alternating current is transmitted through the M pairs of fixed magnetic poles and the N pairs of rotating magnetic poles, so that the magnetic pole quality and the space are saved, the cost is greatly saved compared with a three-machine brushless excitation system, meanwhile, the length of a shafting can be reduced, and the stability of the shafting of the system is improved.

(4) The self-shunt excitation brushless excitation system of the generator provided by the invention has the advantages that the materials, the pole pair number, the size, the layout, the square wave frequency, the magnetic path channel and the like of the fixed magnetic pole and the rotating magnetic pole are flexibly adjustable, and the self-shunt excitation brushless excitation system of the generator has higher energy transmission efficiency by adjusting the parameters.

(5) The self-shunt excitation brushless excitation system of the generator can provide excitation current with proper magnitude for the generator by adjusting the series and parallel relations among the N branches of the rotating part, thereby realizing effective excitation of the generator.

(6) The self-shunt excitation brushless excitation system of the generator provided by the invention can realize the regulation of the excitation current of the generator by controlling the amplitude of the direct-current voltage output by the three-phase rectifier.

Drawings

Fig. 1 is a schematic diagram of a self-shunt excitation brushless excitation system of a generator according to embodiment 1 of the present invention;

fig. 2 is a schematic view of a fixed magnetic pole and a rotating magnetic pole provided in embodiment 1 of the present invention; wherein, (a) is a sectional view of the fixed magnetic pole and the rotary magnetic pole, and (b) is an expanded view of the fixed magnetic pole and the rotary magnetic pole;

fig. 3 is a schematic diagram of an excitation direction of a fixed magnetic pole, a schematic diagram of a waveform of a rotating magnetic pole induction and a schematic diagram of an input waveform of a single-phase rectifier according to embodiment 1 of the present invention; wherein, (a) is the schematic diagram of the excitation direction of the fixed magnetic pole, (b) is the schematic diagram of the induction waveform of the rotating magnetic pole, and (c) is the schematic diagram of the output waveform of the single-phase rectifier;

FIG. 4 is a schematic diagram of the parallel connection and the series connection of the branches provided in embodiment 1 of the present invention; wherein, (a) is a schematic diagram of two branches connected in parallel, and (b) is a schematic diagram of two branches connected in series;

fig. 5 is a schematic structural diagram of a single-phase rectifier according to embodiment 1 of the present invention; wherein, (a) is a rectifier based on a diode, (b) is a rectifier based on a fully-controlled device, and (c) is a rectifier based on a diode and connected with a current-sharing resistor in series;

FIG. 6 is a schematic view of a fixed magnetic pole and a rotating magnetic pole provided in embodiment 2 of the present invention; wherein, (a) is a sectional view of the fixed magnetic pole and the rotary magnetic pole, (b) is an expanded view of the fixed magnetic pole and the rotary magnetic pole, and (c) is a schematic view of the excitation direction of each fixed magnetic pole;

fig. 7 is a schematic diagram of the excitation direction of the fixed magnetic pole, a schematic diagram of the waveform of the rotating magnetic pole induction and a schematic diagram of the input waveform of the single-phase rectifier according to embodiment 2 of the present invention; wherein, (a) is the schematic diagram of the excitation direction of the fixed magnetic pole, (b) is the schematic diagram of the induction waveform of the rotating magnetic pole, and (c) is the schematic diagram of the output waveform of the single-phase rectifier.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

In the present application, the terms "first," "second," and the like (if any) in the description and the drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

In order to solve the technical problems that the existing self-shunt excitation system of the generator is easy to generate mechanical faults, easily causes pollution to a motor winding and accidents due to the use of a carbon brush and a slip ring, so that the excitation system requires regular maintenance and is difficult to be applied to occasions such as small and medium explosion-proof motors and the like, the invention provides a self-shunt excitation brushless excitation system of the generator and application thereof, and the whole idea is as follows: the generator terminal voltage supplies power to an excitation system to realize a self-shunt excitation mode; on the basis, N pairs of rotating magnetic poles which rotate coaxially with a generator rotor and N single-phase rectifiers which are correspondingly connected in series form a rotating part, the rotating part realizes energy transmission through electromagnetic induction between the rotating magnetic poles and the fixed magnetic poles and excites the generator, so that a carbon brush and a slip ring are omitted, the defects caused by the carbon brush and the slip ring are overcome, the maintenance cost is reduced, the operation reliability of the system is improved, and the excitation system can be suitable for occasions such as small and medium-sized explosion-proof motors.

The following is example 1.

Example 1:

a self shunt excitation brushless excitation system for a generator, as shown in fig. 1, comprising:

the high-voltage side of the excitation transformer is connected with the generator end of the generator and is used for carrying out voltage reduction treatment on the generator end alternating-current voltage of the generator;

a three-phase rectifier, i.e. AC/DC 1 in fig. 1, having an AC side connected to the low-voltage side of the excitation transformer, for rectifying the AC voltage output from the excitation transformer into a DC voltage;

the input end of each high-frequency alternating current generator is connected with the output end of the three-phase rectifier and used for converting the direct-current voltage output by the three-phase rectifier into P high-frequency alternating-current voltage with controllable phase difference;

m pairs of fixed magnetic poles arranged along the first circumference are connected with the output end of the P-path high-frequency alternating current generator, a plurality of pairs of fixed magnetic poles connected to the same path of high-frequency alternating current generator are mutually connected in parallel, and the high-frequency alternating current voltage output by the P-path high-frequency alternating current generator supplies power;

the N pairs of rotating magnetic poles arranged along the second circumference rotate coaxially with the rotor of the generator and are used for inducing alternating-current voltage on each pair of rotating magnetic poles through electromagnetic induction between the N pairs of fixed magnetic poles; the first circumference is concentric with the second circumference;

n single-phase rectifiers, namely AC/DC 2 shown in fig. 1, which rotate coaxially with the rotor of the generator, are respectively connected in series with the N pairs of rotating magnetic poles to form N branches, each single-phase rectifier being configured to rectify an AC voltage output by the pair of rotating magnetic poles connected in series with the rectifier into a DC voltage; the N branches are connected in parallel and/or in series and then are connected in series with an excitation winding of the generator to provide excitation for the generator;

m, N and P are preset positive integers, which can be determined according to requirements such as actual energy transmission efficiency, and in this embodiment, M is 4, and N is 4;

in this embodiment, one magnetic pole of each pair of fixed magnetic poles is excited in the forward direction, and the other magnetic pole is excited in the reverse direction, so as to form closed magnetic force lines; in practical application, according to the magnetic material, structure and wiring mode of the rotor and the requirement of magnetic resistance, the magnetic poles excited in the forward direction and the magnetic poles excited in the reverse direction in the M pairs of fixed magnetic poles are arranged at intervals in a crossed manner, or the magnetic poles excited in the forward direction and the magnetic poles excited in the reverse direction are symmetrically arranged (such as up-down symmetry, left-right symmetry and the like) about the diameter of the first circumference; as an alternative implementation manner, in this embodiment, the magnetic poles excited in the forward direction and the magnetic poles excited in the reverse direction are arranged in a crossed and spaced manner, as shown in (a) in fig. 2, and during operation, the excitation direction in each fixed magnetic pole is fixed, as shown in (b) in fig. 2; as shown in fig. 2 (a), the outer side is a fixed magnetic pole, and the inner side is a rotating magnetic pole;

in order to realize current sharing or reduce voltage ripples, in practical application, the P-path high-frequency alternating current generator can be controlled to enable the converted high-frequency alternating current voltages to have a proper controllable phase difference, and under special conditions, the phase difference can be controlled to be zero, and at the moment, each path of high-frequency alternating current voltage is an in-phase signal; as an alternative implementation, in this embodiment, the high-frequency ac generator is embodied as a chopper, so that the dc voltage output by the three-phase rectifier can be converted into a high-frequency square wave, and power can be supplied to the fixed magnetic poles, so that the excitation direction in each pair of fixed magnetic poles is fixed positive and negative, and forward excitation and reverse excitation are respectively generated, as shown in (a) in fig. 3; it should be noted that, in some other embodiments of the present invention, other devices such as an igbt (insulated Gate Bipolar transistor), an IGCT (Integrated Gate-shared resistor), and the like may also be used as the high-frequency ac generator to convert the dc voltage into the high-frequency ac voltage;

during the rotation process of the rotating magnetic poles, high-frequency square waves with amplitude changes are induced on the corresponding rotating magnetic poles in real time, as shown in (b) in fig. 3, then the high-frequency square waves are rectified by a single-phase rectifier to obtain direct-current voltage, and N branches are connected in parallel to supply power for an excitation winding of the generator. In the control process, the output waveform of the single-phase rectifier is shown as (c) in fig. 3, the control mode is simple and easy to realize, and the fixed magnetic poles and the rotating magnetic poles are arranged at equal intervals, so that the cost is saved.

Taking any two branches as an example, the parallel connection mode and the series connection mode of the two branches are respectively shown as (a) and (b) in fig. 4; in practical application, the serial or parallel connection mode between the branches can be set according to the actual exciting current of the generator; when the exciting current required by the generator is large, all the branches can be connected in parallel to supply power for the exciting winding of the generator; when the exciting current required by the generator is small, the branch circuits can be connected in series to supply power for the generator exciting winding, or part of the branch circuits can be connected in series and then connected in series with the rest branch circuits to supply power for the generator exciting winding.

In this embodiment, the three-phase rectifier may select any structure capable of rectifying the three-phase ac voltage into dc voltage for output, for example, the three-phase rectifier is a two-level structure, a three-level structure or a multi-level structure based on a thyristor of a half-control device, or the three-phase rectifier is a two-level structure, a three-level structure or a multi-level structure based on a full-control device, and the like, and is selected accordingly according to specific application requirements in practical application; the excitation current of the generator can be adjusted by controlling the amplitude of the direct-current voltage output by the three-phase rectifier.

In this embodiment, the single-phase rectifier may be any one of structures that can rectify a single-phase ac voltage into a single-phase dc voltage output, for example, the single-phase rectifier may be a diode-based rectifier as shown in (a) in fig. 5, thereby achieving the normal functions of supplying power to and deactivating magnetism of the excitation winding; the single-phase rectifier can also be a rectifier based on a full-control device as shown in (b) in fig. 5, the energy of the rectifier can flow in two directions, inversion demagnetization can be realized, the control is more flexible, and multi-module dynamic current sharing control can be realized; the single-phase rectifier may also be a rectifier based on a diode and connected in series with a current sharing resistor as shown in fig. 5 (c), and the current sharing resistor may also be a specially designed resistor with a small positive temperature coefficient resistance, so as to achieve a good natural current sharing effect; more optional single-phase rectifier structures will not be listed, and in practical application, the single-phase rectifier structures are selected according to specific application requirements, and in practical application, the single-phase rectifier structures can also adopt three-level or multi-level structures according to actual needs.

The generator self-shunt excitation brushless excitation system provided by the embodiment is supplied with power by generator terminal voltage to provide excitation for the generator, so that a self-shunt excitation mode is realized; on this basis, in the excitation system provided by the embodiment, the N pairs of rotating magnetic poles rotating coaxially with the generator rotor and the N single-phase rectifiers form a rotating part, the rotating part realizes energy transmission through electromagnetic induction between the rotating magnetic poles and the fixed magnetic poles, and supplies power to the excitation winding of the generator, so that a carbon brush and a slip ring are omitted, and the technical problems that mechanical faults are easy to occur, motor winding pollution is easy to cause and accidents are easy to occur due to the use of the carbon brush and the slip ring in the traditional self-shunt excitation system are effectively solved while self-shunt excitation is realized, the system operation reliability is effectively improved, and the maintenance cost is reduced.

Example 2:

a self-shunt excitation brushless excitation system of a generator, which is similar to the above embodiment 1, except that in this embodiment, M pairs of fixed magnetic poles are arranged without gap, as shown in (a) of fig. 6, and in the working process, the excitation direction of each rotating magnetic pole after induction is fixed, and the excitation directions of each rotating magnetic pole and the fixed magnetic pole opposite to the rotating magnetic pole are the same, as shown in (b) of fig. 6; without loss of generality, in the present embodiment, M is 8, N is 4; as shown in fig. 6 (a), the outer side is a fixed magnetic pole, and the inner side is a rotating magnetic pole;

during the excitation process, the position of each rotating magnetic pole is detected in real time through corresponding control, and the fixed magnetic pole at the corresponding position is set by combining the excitation direction required by each rotating magnetic pole, so that the excitation directions of the fixed magnetic pole and the rotating magnetic pole are the same, namely, the fixed magnetic pole opposite to the rotating magnetic pole with negative excitation can always provide negative excitation, and the fixed magnetic pole opposite to the rotating magnetic pole with positive excitation can always provide positive excitation, as shown in (c) of fig. 6, in the figure, the time is represented in the transverse direction;

in this embodiment, the chopper is used as a high-frequency ac generator to convert the dc voltage output by the three-phase rectifier into a high-frequency square wave and supply power to the fixed magnetic poles, so that two magnetic poles of each pair of fixed magnetic poles respectively generate forward excitation and backward excitation, as shown in (a) of fig. 7, in the above control manner, a high-frequency square wave with an unchanged amplitude is induced on the rotating magnetic poles in real time, as shown in (b) of fig. 7, the high-frequency square wave passes through the single-phase rectifier to obtain a dc power, and the dc power output by the parallel connection of the N branches supplies power to the excitation winding. In the control process, the output waveform of the single-phase rectifier is as shown in (c) of fig. 7, and the energy transmission efficiency is high in the magnetic pole arrangement mode and the control mode.

Example 3:

an electrical generator system comprising: a generator and a self shunt excitation brushless excitation system for the generator provided in embodiment 1 or 2 above.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.