RU2524776C1 - Starting gas turbine engine by contactless salient-pole sync generator with rotating rectifier - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: at initial period of gas turbine engine starting, primary generator armature winding and exciter excitation winding are connected via control unit to power supply. Note here that said control unit allows primary generator magnetic flux vector advance relative to rotor pole axis while gas turbine engine is accelerated by reactive moment. As rpm increases, induced e.m.f. in exciter armature winding rectified by rotating rectifier feeds the primary generator excitation winding to generated active torque. At reached preset rpm control unit is disconnected from primary generator winding while contactless salient-pole sync generator changes over to generator mode.

EFFECT: decreased ballast flight weight, simplified design.

3 dwg

Description

The invention relates to the field of aviation technology, and in particular to the process of starting gas turbine engines.

The invention can find application in electrical engineering, as well as in those areas of technology where an autonomous source of electrical and mechanical energy is needed, combining the quality of reliability with high specific power and good regulatory characteristics.

One of the types of engines of autonomous objects, including modern aircraft, are gas turbine engines.

Starting a gas turbine engine is one of the main operations in preparing an aircraft for flight.

The most widely used are turbostarter and electric starting methods [1, p. 61].

A turbostarter start of a gas turbine engine is known, in which a turbocompressor starter is used as a starter, which is a small gas turbine engine [1, p. 62] with a limited duration of operation in the starter mode.

The use of turbostarters complicates the production and operation of a gas turbine engine, increases the overall start time.

A known electrical method for starting a gas turbine engine.

To start a gas turbine engine on aircraft, mainly electric starters or starter-generators are used.

The electric starter, which is a separate structural unit of relatively large mass and dimensions, performs the launch function and is subsequently an unused load that increases the flight mass of the aircraft.

The most widely used for starting modern gas turbine engines are starting systems with starter generators.

Known starter-generator of direct current having a brush-collector assembly [2, p. 193-195]. The main disadvantage of this design is the low reliability due to the presence of a brush-collector assembly.

Known non-contact synchronous generator with a rotating rectifier, consisting of three electrical machines: the main generator, pathogen, exciter, having a common casing and shaft [2, p.184-185]. The disadvantage of the design is irreversibility, i.e. the impossibility of the generator in motor mode.

Closest to the claimed technical solution is a non-contact synchronous starter-generator with a rotating rectifier, consisting of three electrical machines: the main generator, pathogen, exciter, and for the implementation of the motor (starter) mode, an asynchronous machine with a phase rotor is used as a pathogen [3, 4 p. 122]. In the motor mode, the exciter works as a rotating transformer [4 p. 122], in the generator mode - as an implicit synchronous generator [4 p. 125]. This method of providing excitation significantly (from 2 to 2.5 times) increases the mass of the pathogen compared with the pathogen of a contactless synchronous generator with a rotating rectifier, which ultimately contributes to an increase in the mass of the starter-generator as a whole by 10-15% [4 pp. .125-126].

Taking into account the conditions for starting a gas turbine engine, it should be noted that the main moment of resistance, which must be overcome by the starter-generator in the process of starting the gas turbine engine, is created by the compressor. This moment is proportional to the square of the compressor speed n and is characterized by the dependence:

M _sopr = A _k · n ² ,

where A _k is a constant characterizing the parameters of the compressor.

Thus, at the initial moment of start-up, the starter-generator must develop the moment necessary to overcome only the inertia of the rotating parts [5, p. 199].

In connection with the foregoing, the technical solution proposed in [3] is not optimal for the implementation of starting a gas turbine engine due to an unjustified increase in the mass of the pathogen.

The objective of the invention is to launch a gas turbine engine using a non-contact explicit pole synchronous generator with a rotating rectifier.

The technical result to which the proposed solution is directed is to use a non-contact explicit pole synchronous generator with a rotating rectifier mounted on board the aircraft as a device for starting a gas turbine engine, which ultimately leads to a decrease in ballast flight mass and simplification of design aircraft engine due to the rejection of the classic starter.

The problem is solved as follows. The gas turbine engine is started by a non-contact explicit pole synchronous generator with a rotating rectifier, containing the main generator, pathogen and exciter. At the initial moment of starting the gas turbine engine, the armature winding of the main generator and the excitation winding of the pathogen are connected to the power source through the control unit, while the control unit advances the magnetic flux vector of the main generator relative to the axis of the rotor pole, and the initial spin of the gas turbine engine is carried out by the reactive moment, and with an increase frequency of rotation induced electromotive force in the winding of the armature of the pathogen, rectified by a block of a rotating rectifier, itaet field winding of the main generator, creating an active torque, and when it reaches a predetermined speed, the control unit is disconnected from the main generator windings, a non-contact salient-pole synchronous generator with a rotating rectifier as a generator.

The layout of the main generator, pathogen and exciter of the non-contact explicit pole synchronous generator with a rotating rectifier and the connection diagram of the windings in the motor mode are shown in Fig. 1 and Fig. 2, Fig. 3 is an example of a control part of a control unit.

An anchor of the main generator 2 with the armature winding 3, an inductor of the explicit-pole synchronous exciter of the reversed structure 4 with the field winding 5, the armature of the synchronous exciter 6 with the armature winding 7, and the rotor module are installed in the housing 1 of the non-contact explicit pole synchronous generator with a rotating rectifier. The rotor module (rotor) contains a shaft 8 common to three electric machines, mounted in bearing bearings. On the shaft of the rotor module are fixed explicit poles of the main generator 9 with an excitation winding 10, a block of a rotating rectifier 11, an armature of a synchronous exciter 13 with a winding 14 and a system of permanent magnets 15 of a synchronous exciter. The armature winding of the synchronous exciter 14 is connected through a block of a rotating rectifier 11 with the excitation winding 10 of the main generator.

To use a non-contact explicit-pole synchronous generator with a rotating rectifier in motor mode, a non-contact synchronous generator with a rotating rectifier, for example, is supplemented with a rotor position sensor 16, mechanically connected to the rotor module, and a control unit 17, the input of which is connected to the power source, and the outputs are connected to the phases the anchor winding of the main generator 3 and the field winding of the pathogen 5.

The control unit 17 consists of a power and control part. The power part of the control unit 17 is a classic three-phase inverter, which commutes the phase of the armature winding of a non-contact explicit pole synchronous generator. The power part is supplied either from a direct current source or through a rectifier from an alternating current source.

The control part of the control unit 17 is built on the basis of vector control, a variant of the structural diagram of the control part is presented in figure 3.

In motor mode, to obtain information about the position of the rotor instead of the rotor position sensor, it is possible to use one of the sensorless control algorithms.

Contactless synchronous generator with a rotating rectifier operates in a motor mode as follows. At the initial moment of start-up, the control unit 17 connects the armature winding 3 of the main generator and the field winding of the pathogen 5 to the power source.

The control unit, according to the signals of the rotor position sensor 16, generates the current vector of the armature winding 3 of the main generator and, therefore, the magnetic flux vector of the main generator so that the axis of the magnetic flux is ahead of the axis of the rotor pole by an angle θ.

In the interaction of the magnetic field of the main generator and the pronounced poles of the rotor of the main generator, a reactive torque occurs [6, p. 212-214], equal to

$$M_p=\frac{m_{\mathrm{one}}\cdot U_{\mathrm{one}}^2}{2\cdot {\omega }_{\mathrm{one}}}\cdot \left(\frac{\mathrm{one}}{X_q}-\frac{\mathrm{one}}{X_d}\right)\cdot \sin \left(2\cdot \theta \right),\left(\text{one}\right)$$

where m ₁ is the number of phases of the winding of the armature of the main generator,

U ₁ - phase voltage supplied to the winding of the armature of the main generator,

ω ₁ - angular synchronous speed,

X _d - inductive resistance of the winding of the armature of the main generator along the longitudinal axis,

X _q - inductive resistance of the armature winding of the main generator along the transverse axis.

Under the influence of a reactive moment, the rotor of a contactless synchronous generator with a rotating rectifier is driven into rotation.

As follows from formula (1), the maximum reactive moment occurs at an angle θ = 45 °. In this regard, at the time of start-up, in order to create the maximum reactive moment, the control unit 17 regulates the current vector of the armature winding of the main generator 3 so that the angle 9 is 45 °.

Under the influence of a reactive torque, as the rotation frequency increases, an electromotive force is induced in the winding of the pathogen armature 14, which is rectified by the rotary rectifier unit 11 and ensures current flow through the excitation winding of the main generator 10, creating an additional active torque equal to [6, p. 213]

$$M_{\mathrm{about}\mathrm{from}n}=\frac{m_{\mathrm{one}}\cdot E_0\cdot U_{\mathrm{one}}}{X_d\cdot {\omega }_{\mathrm{one}}}\cdot \sin \left(\theta \right),\left(\text{2}\right)$$

where E ₀ is the electromotive force of the generator armature winding induced by the excitation winding current of the main generator.

Under the action of the total moment (M _p + M _DOS ), the rotor speed increases.

To create maximum torque during the spinning process, the control unit 17, based on the signals of the rotor position sensor 16, controls the position of the current vector of the armature winding of the main generator 3 relative to the axis of the rotor poles, for example, according to the following law:

$$\theta \equiv f\left(I_f,{\omega }_{\mathrm{one}},U_c,L_d,L_q\right)\equiv \left(\frac{\sqrt{{\left(I_f\cdot {\omega }_{\mathrm{one}}\cdot L_q\right)}^2+8\cdot {\left(U_c\cdot \left(L_d-L_q\right)\right)}^2-I_f\cdot {\omega }_{\mathrm{one}}\cdot L_q}}{\mathrm{four}\cdot U_c\cdot \left(L_d-L_q\right)}\right),\left(\text{3}\right)$$

where I _f is the excitation winding current of the main generator, determined by the rotor speed and the excitation winding voltage of the pathogen,

L _d is the inductance along the longitudinal axis,

L _q is the inductance along the transverse axis.

The excitation winding current of the main generator 10 can be expressed as:

$$I_f=k\cdot I_{BB}\cdot {\omega }_{\mathrm{one}},\left(\text{four}\right)$$

where I _BB is the excitation current of the pathogen,

k is the design coefficient.

Upon reaching the rotational speed of the rotor module, determined by the parameters of the gas turbine engine, the non-contact explicit-pole synchronous generator with a rotating rectifier enters the generator mode, the control unit 17 is disconnected from the winding of the generator armature 3.

The proposed technical solution implements the functions of the motor mode in the generator without changing the design, increasing mass, preserving the advantages of a non-contact explicit-pole synchronous generator with a rotating rectifier [7, p. 14], which is currently the main type of electric energy source on board most operating aircraft. At the enterprise of OJSC "Electric Drive", Kirov, an experimental verification of the proposed solution was carried out (Act No. 07541905-98 / 2-2010). The results confirmed the correctness of the proposed technical solution and the feasibility of its use in the implementation of the program "Fully Electrified Aircraft".

Link to the source of fame

[1] Aircraft equipment. / Yu.A. Andrievsky, Yu.E. Voskresensky, Yu.P. Dobrolensky et al .; Ed. Yu.P. Dobrolensky. - M: Military Publishing, 1989 .-- 248 p.: Ill. - (Military aircraft)

[2] Electrical equipment of aircraft: a textbook for high schools. In two volumes / Edited by S.A. Gruzkova. Volume 1. Aircraft power supply systems. - M.: Publishing House MPEI, 2005. - 568 p.

[3] United States Patent No. US 2009/0174188 A1

[4] Levin A.V. Electric plane: from idea to implementation. / A.V. Levin, I.I. Alekseev, S.A. Kharitonov, L.K. Kovalev // M .: Mechanical Engineering, 2010 .-- 288 p.

[5] K.S. Bobov, V.A. Vinokurov, B.C. Askerko, M.V. Kravchuk, G.I. Panasyuk Aircraft electric machines. Part 1. Machines of direct and alternating current. Transformers / Ed. K.S. Bobova. - VVIA them. prof. NOT. Zhukovsky; 1960 .-- 642 p.

[6] Katsman M.M., Yuferov F.M. Electric machines of automatic systems: a textbook for technical schools. / Edited by F.M. Yuferova. - 2nd ed., Revised. and add. - M .: Higher. school; 1979.- 261 p.

[7] Valve generators of autonomous power supply systems. / N.M. Rozhnov, A.M. Rusakov, A.M. Sugrobov, P.A. Tyrichev; Ed. P.A. Tyricheva - M.: Publishing House MPEI, 1996. - 280 p.

Claims (1)

A method of starting a gas turbine engine, carried out by a non-contact explicitly polarized synchronous generator with a rotating rectifier containing a main generator, a pathogen and exciter, characterized in that at the initial moment of starting a gas turbine engine, the armature winding of the main generator and the excitation winding of the pathogen are connected to the power source through the control unit, while the control unit provides advance of the magnetic flux vector of the main generator relative to the axis of the rotor pole, and the initial the spinning of the gas turbine engine is carried out by the reactive moment, and with an increase in the frequency of rotation, the induced electromotive force in the exciter armature winding, rectified by the rotating rectifier unit, feeds the excitation winding of the main generator, creating an active torque, and, when the set speed is reached, the control unit is disconnected from the main winding generator, and the non-contact explicit pole synchronous generator with a rotating rectifier goes into generator mode.

Images