RU2624772C2 - Turbogenerator unit of three-phase currents of two different frequencies - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: proposed turbo generator contains a ferromagnetic stranded stator comprising two distributed three-phase windings of a three-phase alternating current of increased frequency F1 And power frequency FS=50 Hz with the number of pairs of poles p₁ and p₂. And p₁>p_2, and a rotating ferromagnetic rotor. The rotor consists of two parts, on the external surfaces of which there are two distributed excitation windings in the slots. DC excitation winding with pole pairs number p₁ is connected to the output of the brushless excitation device. Three-phase winding of excitation of an alternating current with the number of pairs of poles p₂ is connected through contact rings and brushes to a three-phase output of a reversible frequency converter.

EFFECT: reduction of the estimated total power of the converting devices, their total mass and dimensions.

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Description

1.1. Technical field

The invention relates to the field of electrical engineering, in particular to synchronous electric three-phase alternating current turbogenerators with electromagnetic excitation and with additional windings both on the stator and on the rotor for generating voltages of two different frequencies.

1.2. State of the art

A known three-phase current generator with electromagnetic excitation, consisting of a charged magnetic core (stator) with a cylindrical bore and grooves on its inner surface, in which there is a distributed winding of an alternating three-phase current and from a ferromagnetic rotor mounted on a shaft, resting its ends on bearings, one of the ends of which are connected to a drive motor (turbine) [1].

In the grooves of the ferromagnetic rotor of an implicit pole design, a DC excitation winding is laid, which is electrically connected to a rotating rectifier of a brushless excitation device rigidly fixed to the shaft end [2]. The DC excitation winding is powered by the electric power of the brushless excitation device when the rotor rotates from the drive motor.

In the indicated turbogenerator, when the rotor rotates as a result of the interaction of the magnetic field of the rotating direct current excitation winding with the stator winding, an alternating three-phase electromotive force (emf) is induced in it, which should later be synchronized in magnitude, frequency and phase when connected to an external network with external voltage.

The magnitude of the first (main) harmonic emf E ₁ and its frequency in the General case is determined by the formulas [1]:

,

,

Where:

- W is the number of turns in the phase of the stator winding;

- F ₁ - the first harmonic flux linkage phase of the stator winding, WB;

- k _{about 1} ^_ winding coefficient;

- k _{p. 1} - bevel coefficient of grooves;

- частота переменной э.д.с, Гц;-

- frequency of the variable emf, Hz;

- p ₁ - the number of pairs of poles of the stator winding and rotor;

- n ₁ - rotor speed, rpm

In accordance with formula (2), a three-phase voltage of an industrial frequency of 50 Hz at the output of a synchronous turbogenerator with p ₁ = 1 is inducted at the maximum possible rotor speed n ₁ = 3000 rpm.

It is known that steam (gas) turbines, which are the driving engines for the turbogenerator, have the best technical and economic indicators (specific fuel consumption, efficiency, specific power, etc.) at higher rotational speeds n≥6000 rpm [3].

The disadvantage of this technical solution of a turbogenerator of alternating voltage of an industrial frequency of 50 Hz is that an intermediate mechanical gearbox is used for its drive [3], which leads to an increase in the mass, dimensions and cost of the entire turbine unit as a whole.

Another close in technical essence to the claimed device is a technical solution used in an electric machine frequency converter with a phase rotor [1], in which when the rotor rotates from a drive motor, incl. at a higher rotational speed, and when a three-phase voltage of one frequency is applied from the rotor side, a three-phase voltage of another frequency can be obtained from the stator side, incl. industrial frequency 50 Hz.

The indicated technical solution [1] found implementation in the method and control device of an autonomous asynchronous generator [4] (analog), in the circuit of the three-phase winding of the rotor of which an adjustable frequency converter is used. When changing, for example, with an increase in the speed of the drive motor, the frequency and amplitude of the induced emf remain constant in a three-phase stator winding support by appropriate regulation in the direction of decreasing the frequency and amplitude of the three-phase current at the output of said frequency converter.

The disadvantage of this technical solution is the inability to generate alternating three-phase voltages of two different frequencies.

The closest in technical implementation to the claimed device is the technical solution of the main turbogenerator of increased frequency (200 Hz or more) as part of the ship's unified electric power system (EEES) [5], the rotation of which is carried out directly from the turbine at a speed of n≥6000 rpm ( prototype).

However, in this prototype there is no possibility of generating an alternating three-phase voltage of an industrial frequency of 50 Hz, which is necessary for supplying general ship consumers. To supply general ship consumers with a three-phase current of an industrial frequency of 50 Hz as part of the ship's EEES [5], converter devices are used, namely cascade matrix frequency converters (KMPCH) with parallel connection of cascades as part of a centralized power take-off system (COM), which in turn is powered by main turbogenerators of increased frequency. Moreover, the total capacity of these KMPCH should be at least the sum of the total capacities of the said consumers, taking into account their possible overloads, which is the reason for the increase in mass, dimensions and cost of the whole EAEU as a whole, despite the use of increased frequency.

The objective of the proposed technical solution is to significantly reduce the estimated apparent power of the necessary converting devices, their total weight and dimensions as part of the ship EEEC.

The technical result of the proposed device for a three-phase current turbogenerator of two different frequencies is that when using the method [6], along with the generation of electricity of two different frequencies — an increased frequency of 200 Hz and an industrial frequency of 50 Hz — at the same time they reduce the estimated apparent power of the necessary converting devices approximately 50% of the total capacity of all general ship consumers of industrial frequency, taking into account their possible overloads.

и промышленной

), содержащем ферромагнитный шихтованный статор с цилиндрический расточкой, на внутренней поверхности которой в общих пазах размещены две распределенные трехфазные обмотки переменного трехфазного тока повышенной частоты f1 и промышленной частоты fs=50 Гц - основная и дополнительная - с числом пар полюсов соответственно p₁ и p₂ при соблюдении условия p₁>p₂, и вращающийся ферромагнитный ротор неявнополюсной конструкции, состоящий из двух частей, насаженных на общий вал и расположенных внутри расточки статора, на наружных поверхностях которых в пазах размещены две распределенные обмотки возбуждения, причем на основной части ротора размещена обмотка возбуждения постоянного тока с числом пар полюсов p₁, подключенная к выходу устройства бесщеточного возбуждения, предусмотрены следующие отличия:The specified technical result is achieved by the fact that in the proposed device of the turbogenerator of three-phase currents of two different frequencies (increased

and industrial

), containing a ferromagnetic charged stator with a cylindrical bore, on the inner surface of which in the common grooves are two distributed three-phase windings of an alternating three-phase current of increased frequency f1 and industrial frequency fs = 50 Hz - the main and additional - with the number of pole pairs, respectively, p ₁ and p ₂ subject to the condition p _1> p _2, and a rotating ferromagnetic rotor neyavnopolyusnoy structure consisting of two parts, fitted on a common shaft and disposed inside the stator bore, on the outer surface of which in two grooves arranged distributed field winding, wherein the primary part of the rotor field winding is placed dc number of pairs of poles p _1, connected to the output device of the brushless excitation provides for the following differences:

основной волны намагничивающей силы трехфазной обмотки возбуждения, размещенной в пазах дополнительной части ротора, поддерживают всегда ниже и в противоположном направлении угловой частоты вращения

ротора, т.е. поддерживают асинхронный режим с отрицательной частотой скольжения

. Указанный режим позволяет по сравнению с КМПЧ в составе централизованной СОМ прототипа [5] существенно уменьшить расчетную полную мощность обратимого преобразователя частоты, следовательно, его общую массу и габариты.1. A three-phase alternating current winding with the number of pole pairs p ₂ placed on the additional part of the rotor (charged) and connected through contact rings and brushes to the three-phase output of the reversible frequency converter is introduced into the grooves of the implicit pole design of the second additional part of the rotor (charge). Rotational speed

the main wave of the magnetizing force of the three-phase field winding, located in the grooves of the additional part of the rotor, always support lower and in the opposite direction of the angular frequency of rotation

rotor, i.e. support asynchronous mode with negative slip rate

. This mode allows, in comparison with the CMPC in the centralized COM prototype [5], to significantly reduce the estimated apparent power of a reversible frequency converter, therefore, its total weight and dimensions.

скольжения в качестве обратимого преобразователя частоты используют каскадный матричный преобразователь частоты, входные клеммы каждого каскада которого соединяют через выключатели и согласующий трансформатор с внешней сетью повышенной частоты

аналогично КМПЧ в составе централизованной СОМ прототипа [5].2. For the implementation in the turbine generator of asynchronous mode with a negative frequency

Slides as a reversible frequency converter use a cascade matrix frequency converter, the input terminals of each stage of which are connected via switches and a matching transformer to an external high-frequency network

similarly KMPCH as part of a centralized COM prototype [5].

1.3. Brief Description of the Drawings

The proposed device is illustrated by a drawing, which shows a block diagram (Fig. 1) of the construction of a turbogenerator of three-phase currents of two different frequencies, which implements a method of generating alternating voltages [6].

In the presented block diagram (Fig. 1), the following notation is used:

1 - stator;

1.1 - the main three-phase winding;

1.2 - additional three-phase winding;

2 - transformer;

3 - switches;

4 - reversible cascade matrix frequency converter (KMPCH);

4.1 - three-phase inputs;

4.2 - three-phase output;

5 - switch;

6 - external network of increased frequency;

7 - switch;

8 - external network of industrial frequency;

9 - the main part of the rotor;

10 - an additional part of the rotor;

11 - drive engine (turbine);

12 - a direct current excitation winding;

13 - three-phase field winding;

14 - brushless excitation device.

1.4. Disclosure of invention

The proposed technical solution consists in the fact that an additional part with a three-phase field winding located in its grooves is introduced into the design of the ferromagnetic rotor located inside the stator bore, and an additional three-phase winding on the stator is introduced, the number of pole pairs of which differs from the number of pole pairs of the main windings located on the stator and on the main part of the rotor. Moreover, in the circuit of a three-phase field winding, located on the additional part of the rotor, a reversible KMPCH is connected, the calculated apparent power of which is significantly less (approximately 50%) of the KMPCH in the centralized COM used in the prototype [5].

The turbogenerator of three-phase currents of two different frequencies has a ferromagnetic charge stator 1 with a cylindrical bore and grooves on its inner surface, in which, along with the main three-phase winding 1.1 of increased frequency voltage, an additional three-phase winding 1.2 of industrial frequency voltage is distributed in the common grooves (Fig. 1) .

и имеющую число пар полюсов p₁=2, соединяют через согласующий трансформатор 2 и выключатели 3 с трехфазными входами 4.1 каждого каскада обратимого КМПЧ 4, а также через выключатель 5 соединяют с внешней сетью 6 повышенной частоты.The main winding 1.1, designed to generate an alternating three-phase voltage, including high voltage, high frequency

and having the number of pole pairs p ₁ = 2, connect through a matching transformer 2 and switches 3 with three-phase inputs 4.1 of each stage of the reversible KMPCH 4, as well as through a switch 5 connect to an external network 6 of high frequency.

и имеющую число пар полюсов p₂=1, соединяют через выключатель 7 с внешней сетью 8 промышленной частоты 50 Гц.An additional three-phase winding 1.2, designed to generate an alternating three-phase voltage of industrial frequency

and having the number of pole pairs p ₂ = 1, connect through a switch 7 to an external network 8 of industrial frequency 50 Hz.

Inside the stator bore 1, there is a cylindrical rotor made of ferromagnetic material, consisting of a main 9 and an additional 10 parts of an implicit pole, mounted on a common shaft, resting its ends on bearings (not shown in the figure), one of the ends of which is connected directly to the drive motor ( turbine) 11.

On the outer surface of each part of the rotor there are grooves. In the grooves of the main part of the rotor 9, a distributed DC excitation winding 12 with the number of pole pairs p ₁ = 2 is placed, and in the grooves of the additional part of the rotor 10 (lined), a distributed three-phase excitation winding 13 with the number of pole pairs p ₂ = 1 is placed.

The DC excitation winding 12 is electrically connected to the output of the brushless excitation device 14 located at one end of the shaft. The three-phase field winding 13 is electrically connected to three contact rings located and rigidly fixed at the other end of the shaft (not shown in the figure).

выходного тока.The contact rings by means of three fixed electric brushes (not shown in the figure) are phase-connected to the three-phase output 4.2 of a reversible cascade matrix frequency converter (KMPCH) 4, with the ability to control the amplitude and frequency

output current.

The device turbogenerator of three-phase currents of two different frequencies according to the proposed technical solution works as follows.

и осуществляют подключение цепи электропитания обмотки возбуждения постоянного тока 12 к устройству бесщеточного возбуждения 14.Pre-driven engine (turbine) 11 start and accelerate the turbogenerator to a speed

and connect the power supply circuit of the DC winding 12 to the brushless excitation device 14.

, которое через согласующий трансформатор 2 и выключатели 3 поступает на трехфазные входы 4.1 каждого каскада обратимого КМПЧ 4.As a result of the interaction of the magnetic field of the rotating DC winding 12 with the main three-phase winding 1.1 of the stator 1, the latter produces an alternating three-phase voltage of increased frequency

which, through the matching transformer 2 and switches 3, enters the three-phase inputs 4.1 of each stage of the reversible KMPCH 4.

в трехфазное напряжение промышленной частоты

, которое при плавном увеличении его амплитуды и частоты от нуля до номинального значения

через трехфазный выход 4.2, электрические щетки и контактные кольца поступает в трехфазную обмотку возбуждения 13 дополнительной части ротора 10.Reversible KMPCH 4 converts an alternating three-phase voltage of high frequency

into three-phase voltage of industrial frequency

which, with a smooth increase in its amplitude and frequency from zero to a nominal value

through a three-phase output 4.2, electric brushes and slip rings enters the three-phase field winding 13 of the additional part of the rotor 10.

которой направлена в противоположную сторону относительно направления вращения обеих частей ротора 9 и 10.Further, the magnetizing currents arising in the three-phase field winding 13 create a spatial main wave (harmonic) of the magnetizing force [1] on the additional part of the rotor 10, the angular frequency of rotation

which is directed in the opposite direction relative to the direction of rotation of both parts of the rotor 9 and 10.

скольжения по способу [6], в соответствии с которым угловую частоту вращения

основной волны намагничивающей силы трехфазной обмотки возбуждения 13 поддерживают всегда ниже угловой частоты вращения

обеих частей ротора 9 и 10.Moreover, in the proposed device of a turbogenerator of three-phase currents of two different frequencies, an asynchronous mode with a negative frequency is used

slip according to the method [6], in accordance with which the angular frequency of rotation

the main wave of the magnetizing force of the three-phase field winding 13 is always kept below the angular frequency of rotation

both parts of the rotor 9 and 10.

In order to exclude mutual electromagnetic influence of both windings located as in the common grooves of the stator 1.1; 1.2, and on both parts of the rotor 12; 13, their number of pole pairs must, in accordance with method [6], satisfy the condition p ₁ > p ₂ .

As a result of the interaction of the total magnetic field from two rotating field windings 12 and 13 with the main 1.1 and additional 1.2 stator windings 1, three-phase variable emfs are induced in them rotation:

- в основной обмотке 1.1;- with frequency

- in the main winding 1.1;

- в дополнительной обмотке 1.2 (знак - «минус» характеризует передачу электроэнергии в сеть).- with slip frequency

- in an additional winding 1.2 (a minus sign indicates the transmission of electricity to the network).

;

через выключатели 5; 7 после их синхронизации по частоте и напряжению поступает во внешние сети 6; 8 переменного напряжения соответствующей частоты.Then, the generated electricity in said windings 1.1; 1.2 stator 1 in the form of three-phase currents of two different frequencies

;

through switches 5; 7 after their synchronization in frequency and voltage enters the external network 6; 8 AC voltage of the corresponding frequency.

скольжения в трехфазной обмотке возбуждения 13, расположенной на дополнительной части ротора 10, индуктируется переменная противо-э.д.с. с частотой

. Под действием этой противо-э.д.с. электроэнергия трехфазных токов через контактные кольца и щетки поступает на трехфазный выход 4.2 обратимого КМПЧ 4.In addition, during the start-up and acceleration of the turbogenerator to the angular frequency of rotation ω ₁ and after putting it into asynchronous mode with a negative frequency

slip in the three-phase field winding 13, located on the additional part of the rotor 10, a variable counter-emf is induced. with frequency

. Under the influence of this counter-emf. the electric power of three-phase currents through the contact rings and brushes is supplied to the three-phase output 4.2 of the reversible KMPCH 4.

поступает на трехфазные входы 4.1 каждого каскада обратимого КМПЧ 4 и через выключатели 3, согласующий трансформатор 2 и выключатель 5 после синхронизации по частоте и напряжению передается во внешнюю сеть 6 повышенной частоты

.The specified electricity after the reverse conversion into a three-phase current with a frequency

arrives at the three-phase inputs 4.1 of each stage of the reversible KMPCH 4 and through the switches 3, the matching transformer 2 and the switch 5 after synchronization in frequency and voltage is transmitted to an external network 6 of increased frequency

.

The estimated apparent power of the proposed turbogenerator device is determined as the sum of the total capacities consumed by external networks from both the main (P _main ) winding 1.1 of stator 1 and the additional (P _extra ) winding 1.2. Moreover, the last P _{add is} usually defined as the sum of the total capacities of all general ship consumers in an external network of industrial frequency 8, taking into account their possible overloads.

The calculated apparent power P _{2 of the} three-phase field winding 13 of the additional part of the rotor 10, as well as the equal calculated apparent power of the reversible KMPCH 4, is determined in accordance with [1] by the formula:

,

,

- скольжение дополнительной части ротора 10 в относительных единицах (знак - «минус» характеризует передачу электроэнергии в сеть).Where:

- sliding of the additional part of the rotor 10 in relative units (the minus sign indicates the transmission of electricity to the network).

Thus, the proposed technical solution for the device of a turbogenerator of three-phase currents of two different frequencies has the necessary justification and, along with the expansion of the functionality of the prototype by the method [6], provides the claimed technical result at a rotor speed of n ₁ = 6000 rpm, i.e. a significant decrease (by ~ 50%) of the estimated apparent power, therefore, the total mass and dimensions of the necessary converting devices (reversible KMPCH) as part of the ship EEES.

Literature

1. Voldek A.I. Electric cars. M .: Energy, 1978. - S. 366; 375; 593.

2. Yakovlev G.S. Ship electric power systems. L .: Shipbuilding, 1987.- S. 61.

3. Block turbogenerators of the TG type. Products of OJSC Kaluga Turbine Plant; internet: www.oaoktz.ru.

4. A method for controlling an autonomous asynchronous generator. Meshcheryakov V.N., Ivanov A.B., Kulikov A.I. RF patent 2213409, cl. H02P 9/00 of 04/26/2001.

5. Ship electric power system of alternating voltage of increased frequency with an electric propulsion system and matrix frequency converters. Aleksandrov V.P., Skvortsov B.A., Hamster V.A. RF patent No. RU 2510781 C2, class. H02J 3/34 dated July 17, 2012.

6. A method of generating alternating voltages of two different frequencies in a three-phase current turbogenerator. Skvortsov B.A. Application for invention No. 201532456 cl. H02P 9/00 from 08/04/2015

Claims (1)

A device for a three-phase current turbogenerator of two different frequencies, containing a ferromagnetic charged stator with a cylindrical bore, on the inner surface of which are two distributed three-phase windings of an alternating three-phase current of increased frequency f ₁ and industrial frequency f _s = 50 Hz with the number of pole pairs, respectively, p ₁ and p ₂ subject to the condition p _1> p _2, and a rotating ferromagnetic rotor neyavnopolyusnoy structure consisting of two parts, fitted on a common shaft and disposed within a bore Ator, the outer surfaces of which two distributed field winding placed in slots, wherein the main part of the rotor is placed DC field winding with the number of pairs of poles p _1, connected to the output device of the brushless excitation, characterized in that the introduced three-phase alternating current excitation winding with a number of pairs of poles p ₂ located on the additional part of the rotor (laden), connected through contact rings and brushes to the three-phase output of a reversible frequency converter, as well as In addition to a reversible frequency converter, a cascade matrix frequency converter is introduced, the input terminals of each stage of which are connected via switches and a matching transformer to an external high frequency network f ₁ .

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