WO2011129717A1

WO2011129717A1 - Three-phase electrical reactor with magnetic biasing

Info

Publication number: WO2011129717A1
Application number: PCT/RU2010/000820
Authority: WO
Inventors: Александр Михайлович БРЯНЦЕВ
Original assignee: Bryantsev Alexander Mikhailovich
Priority date: 2010-04-14
Filing date: 2010-12-31
Publication date: 2011-10-20
Also published as: EP2560174A4; UA102354C2; RU2418332C1; EP2560174A1

Abstract

The invention relates to electrical engineering and may be utilized in an electrical circuit for reactive power compensation, voltage stabilization, etc. The reactor comprises three upper and three lower vertical rods. Two-section windings are disposed on the rods. Horizontal yokes have two middle and two end sections, and four magnetic shunts in the form of rectangular frames. The horizontal sections of the shunts are disposed on the ends of the windings along the upper, middle and lower yokes, and the vertical sections are disposed along the lateral yokes. The reactor windings are connected to a three-phase circuit and to controllable semiconductor transducers. Non-magnetic gaps are formed in the sections of the middle horizontal yoke. Each magnetic shunt has two additional vertical sections between the windings. The ratio of the sizes of the non-magnetic gaps of the middle yoke in the end sections Δ_end and in the middle sections Δ_middle is 1.5<(Δ_middle/Δ_end)<3, that between the cross section of the steel of the middle sections of the middle yokes S_m.y. and the cross section of the rods S is 0.9<(S_m.y./S)<1.3, that between the cross section of the steel of all other sections of the yokes S_y. and S is 0.7<(S_y./S)<0.9, and that between the cross section of the steel of all parts of the magnetic shunts S_sh and S is 0.07<(S_sh/S)<0.3.

Description

ELECTRIC THREE PHASE REJECTOR WITH MAGNETIZATION

The invention relates to the field of electrical engineering and can be used for magnetization controlled reactors installed, for example, in an electrical network to compensate for reactive power, stabilize voltage, parallel operation with capacitor banks, increase throughput, etc.

A three-phase electric reactor with magnetization is known [1], which contains a charged magnetic system with upper, lower, middle and two side yokes, coaxial upper and lower rods located on the rods of the upper and lower windings, as well as inputs, semiconductor diodes and thyristors. The disadvantage of this device, an analogue, is the increased consumption of steel of the magnetic circuit due to the increased magnetic flux in it (from the scattering magnetic field) in the load conditions of the reactor, as well as because of the non-optimal choice of the parameters of the magnetic circuit.

This drawback was partially eliminated in [2]. An electric three-phase magnetization reactor contains a charged magnetic system with three upper and three lower coaxial rods, with upper, lower, middle and two side yokes, the horizontal yokes having two middle and two extreme sections. The windings located on each core consist of two parts. The inputs of the reactor are connected to parts of the windings and converters with a control system. Four magnetic shunts are installed in the reactor in the form of rectangular frames with horizontal and vertical parts, and the horizontal parts of the shunts are located at the ends of the windings along the upper, middle and lower yoke, and the vertical parts closing them are located along the side yards. The disadvantage of this device, the prototype, is also the increased consumption of the magnetic circuit steel due to the increased magnetic flux in it (from the scattering magnetic field) in the reactor load conditions due to the suboptimal design and parameters of the shunts and magnetic circuit. In addition, the range of reactor power control is limited and reliability is reduced due to the danger of in cases of high voltage on the control system due to its galvanic connection with the reactor windings.

The aim of the invention is to reduce the consumption of steel and losses, increase reliability, increase the functionality of the reactor — expand the range of power control — by introducing new elements into the design and electrical circuit, new connections between elements, and optimization of parameter ratios.

This goal is achieved by the fact that in an electric three-phase reactor with magnetization, the magnetic system of which is made of charged sheets of electrical steel and contains a magnetic circuit with coaxially located three upper and three lower vertical rods, on which two-section windings are located, the upper, lower and middle horizontal and two lateral vertical yokes, and the horizontal yokes have two middle and two extreme sections, four magnetic shunts in the form of rectangular frames with horizontal vertical and vertical sections, the horizontal sections of the shunts located on the ends of the windings along the upper, middle and lower yoke, and the vertical sections closing them are located along the side holes, and the reactor also contains controllable semiconductor converters of diodes and resistors and a control system, windings are connected to a three-phase network and to converters; three-winding isolation transformers installed between the converters and the control system are introduced into the reactor. Nonmagnetic gaps were made in the sections of the average horizontal yoke of the magnetic core. Each magnetic shunt has two additional vertical sections located between the windings. The ratio of the values of non-magnetic gaps of the magnetic circuit in the extreme sections of the average yoke of Akrain. ^and values of non-magnetic gaps in the middle sections of the average yoke A _avg . (Assigned / Acreyn.) Is

1 _> 5 <(A _average, Δ, φ ₃ β _Η ) <3.

The relationship between the steel section of the middle sections of the middle yoke S _cp. „ _P. and the cross section of the rods S is within

0.9 <(S _cp . _Ap . / S) <l, 3, the ratio between the steel cross section of all other sections of the yoke S _Hp and the cross section of the rods S is within

0.7 <(S „ _p. / S) <0.9,

the ratio between the steel cross section of all parts of the magnetic shunts S _m and the cross section of the rods S is within

0.07 <(S _m / S) <0.3.

The proposed reactor with magnetization is illustrated by drawings. Figure 1 shows the withdrawal part of the reactor (a magnetic system with windings) - front view, figure 2 is the same, top view, figure 3 is the same side view. Figure 4 shows the main magnetic circuit burdened from sheets of electrical steel, figure 5 shows one of the four magnetic shunts burdened from sheets of electrical steel in the form of a rectangular three-window frame. Figure 6 shows the electrical circuit of the reactor.

The magnetic system of the reactor, laden from sheets of electrical steel, consists of a main magnetic circuit and four magnetic shunts.

The magnetic core of the reactor (Figs. 1-4) contains six coaxial rods - three upper 1, 2, 3 and three lower 4, 5, 6. On each rod there is a winding consisting of two sections 7 and 8. There are two lateral vertical yokes 9 and 10, as well as three horizontal yokes - the upper yoke 11, the lower yoke 72, and the average yoke 13. The section of the steel of the rods is S, the section of the steel of all the yokes except the average yoke is S „, the section of the steel of the middle yoke is S _{cp fl} p ..

Each of the horizontal yards 11, 12 and 13 has four sections: two extreme and two middle.

All sections of the average horizontal yoke 13 have non-magnetic gaps 14 (the size of the gap in the middle sections Δ _average ) and 15 (the size of the gap in the extreme sections Δ ^ ,,).

Each of the four magnetic shunts 16 is made in the form of a rectangular three-window frame (Fig. 5). The horizontal parts of the shunts are located at the ends of the windings (between the end of the winding 7 and 8 and the pressing beam 17, Fig.Z). Shunts 16 have two middle vertical parts 18 located between the windings. All parts of magnetic shunts have a steel cross section S _m. .

The electrical circuit of the reactor (Fig.6) contains three input phase network A, B and C. Two sections 7 and 8 of the winding on the upper rod 1 of phase A have taps A1-A2 and AZ-A4, on the lower coaxial rod 4, taps A5-A6 and A7-A8. Two sections of the RB winder on the upper rod of phase 2 have taps B1-B2 and VZ-B4, on the lower coaxial rod 5 - B5-B6 and B7-B8. Two sections of the winding on the upper rod 3 of phase C have taps C1-C2 and C3-C4, on the lower coaxial rod 6 - C5-C6 and C7-C8.

The windings are connected in a circuit of two triangles and connected to the three inputs of the phases of the network A, B and C.

Between each two sections of the windings of each rod, a converter is turned on, consisting of a diode D and a resistor R connected in parallel: converter P _{1A is} connected between taps A2 and A3, converter P _{2A is} connected between taps A6 and A7, and B2 and B3 are tapped between taps A6 and A7 converter _{P] B,} and Wb between the taps V7- P converter _2B, C2 and between the taps SOC - UR converter between the taps Sa and C 7 - transducer n · _2C terminals converters notation means the same as the windings of the taps, which they are connected. In all 6 converters, the diodes D and the resistors R are the same.

Between the control system (SU) and the converters, insulating three-winding transformers Т _А , Т _в and Т _{с are} installed. Each primary sectioned winding of the transformer is connected by its terminals (Um-Ugl. U v-U ₂ v and U] s-U ₂ s) to the control system. Each of the two secondary windings is connected to the taps of the sections of the control windings and the terminals of the converters. The transformer T _{A has} one secondary winding connected to the taps A2 and A6 and simultaneously with the terminals of the transducer A2 and A6, the second one is connected to the taps A3 and A7 and simultaneously with the terminals of the transducer A3 and A7. At transformer T _in one, the secondary winding is connected to bends B2 and Bb and terminals B2 ιι Β6, the second to bends ВЗ and В7 and terminals ВЗ and 57. At transformer T _с, one secondary winding is connected to bends С 2 and С6 and terminals C2 and Sat, the second - with taps SZ and S7 and terminals SZ and S 7.

Converters and isolation transformers are placed on the assembly panel 19, mounted on the withdrawal part (figure 2). The extraction part — the reactor magnetic system (magnetic core and shunts) with windings and structural fittings — is placed in the oil tank.

Consider the operation of the reactor. The reactor is connected to the three-phase network by inputs A, B and C, the mains voltage is supplied to the reactor windings.

To transfer the reactor to the minimum power mode - idle mode - the control system of the control system provides at the terminals U] A ~ U2A, U1V-U2V and U1S-2C the minimum resistance. Since the insulating transformer T _A, T _B and T _c are thus short-circuited, and their resistance to scattering of small outlets sections A2 and A3 windings, Ab and A7, B2 and OT, B6 and B7, C 2 and SZ, C6 and C7 are almost pairwise shorted. Moreover, each of the converters P _1A and P ₂ A, P _1B and P _2B , P _{] C} and P _{2C is} practically short-circuited, and there is no magnetization of the cores of the magnetic circuit.

In the case when the control system of the control system connects the maximum resistance to the U1A-U2A, U1V-U2V, ^and U1S-U2S taps, the reactor switches to the maximum power mode - full-time saturation of the rods. This is due to the fact that the diodes D of the converters P _1L , P ₂ A, P _{1V are} connected to the taps of the sections of the windings A2 and AZ, A6 and A7, B2 and VZ, V6 and V7, C2 and SZ, C6 and C7 , P _2V ,

Intermediate modes from idle to maximum power are provided by the control system of the control system according to a given program (for example, to stabilize the mains voltage) or during manual adjustment. In this case, the rated power mode, as a rule, is set for one of the intermediate modes - the half-period saturation reactor mode. In this mode, the steel of each core of the reactor is in a saturated state for half a period. Such a regime is characterized not only by minimal (theoretically zero) distortions of the reactor current by higher harmonics, but also by the optimal consumption of active materials and optimal losses in the windings.

Isolation transformers are installed between the control system (it is located on the control panel in the room) and the converters, which ensure the absence of galvanic communication and increased safety of personnel and low-voltage equipment from possible high-voltage supply to the control system (for example, in emergency situations). The converters, together with isolating transformers, are located on panel 19 in the reactor tank located in the open area of the substation. Non-magnetic gaps 14 and 75 are made in the sections of the average horizontal yoke 13 of the magnetic circuit. These gaps are necessary in order to expand the limits of regulation of the reactor power. The magnitude of non-magnetic gaps should be minimal; when designing a reactor, it is selected from the technological capabilities of production and usually amounts to fractions or units of millimeters.

In the magnetic circuit, the magnitude of the nonmagnetic gap in the extreme sections of the average yoke A is _extreme . should be less than the non-magnetic gap in the middle sections of this yoke A _average (1.5- ^ 3) times, i.e.

1.5 <(A _sredn / (A _krayn ) <3.

The upper boundary should not be exceeded, otherwise the magnetic flux of scattering in the extreme vertical parts of the shunt will be reduced, and in the middle it will be increased. The lower boundary must also be observed, otherwise the magnetic flux of scattering will be increased in the vertical extreme parts of the shunt, in the middle vertical parts of the shunt will be reduced. Fulfillment of the optimum ratio of the gap sizes allows one to obtain a favorable distribution of magnetic induction over the rods, yokes, and shunts, as well as the minimum steel consumption at the maximum shunt efficiency in terms of unloading the main magnet core of the reactor and reducing additional losses in the structural elements and tank wall .

Of great importance is the choice of the cross-sectional area of steel for all sections of the magnet wire.

The ratio between the steel cross section of the sections of the average yoke S _cp and the cross section of the rods S should be chosen within

0.9 <(S _{cp p} / S) <l, 3.

The relationship between the cross section of the steel of all other sections with the S „ _p . and the cross section of the rods S - must be selected within

0.7 <(S _V. / S) <0.9.

If the cross section of steel with a yoke exceeds the maximum boundary, then the reactor is obtained with an increased consumption of steel in yokes. If the steel cross section of the yoke is less than the minimum value, then steel saturation occurs in the reactor yokes in certain modes of its operation. This leads to adverse events - an increase additional losses due to eddy currents in structural elements, an increase in nonlinear distortions in the reactor current.

Magnetic shunts 16 effectively “channelize” the scattering magnetic flux that occurs when current flows in the windings, i.e. in all modes when magnetizing rods. The scattering magnetic flux circulates axially inside the windings and closes by the yokes of the magnetic system and by magnetic shunts. If there are no magnetic shunts 16, then the magnetic flux closes along the structural elements and the tank wall, causing eddy currents, additional losses and unacceptable heating in them. For effective magnetic flux closure, shunts have middle longitudinal vertical sections 18 located between the windings. These two additional (in comparison with the prototype) vertical sections are necessary for the optimal distribution of magnetic fluxes of scattering and to reduce the total consumption of steel in shunts and magnetic core.

The steel cross section of magnetic shunts should be the larger, the larger the radial size of the windings, because when the reactor is loaded, an increased magnetic flux of scattering occurs (in comparison with the magnetic flux in the rods and yokes of the magnetic circuit in idle mode).

The ratio between the steel cross section of all parts of each of the magnetic shunts S, _JJ and the cross section of the rods S should be selected within

0.07 <(S _w / S) <0.3.

If the steel cross section of the magnetic shunts is chosen to be larger than the maximum value of the given ratio, then an overspending of steel is obtained. If the steel cross section of the shunts is less than the minimum value, then the shunts become ineffective and do not shield the scattering flux of the windings. This leads to adverse phenomena - an increase in magnetic induction in the magnetic circuit, the main losses in steel and additional losses in structural elements.

The proposed “three-window” shunt design improved in comparison with the prototype provides an optimal distribution of the magnetic fluxes of the reactor, and, consequently, an optimal consumption of steel in the magnetic system. All the considered limits of optimal size ratios were determined as a result of the analysis of numerous calculations on mathematical models controlled by magnetization of reactors in a wide range of variation of their parameters. If necessary, the examination can be provided with the detailed results of these calculations.

A high voltage reactor is typically oil cooled. The extraction part — the reactor magnetic system (magnetic core and shunts) with windings and press fittings — is located in the oil tank, and the reactor inlets are on the tank cover. Converters and isolation transformers are located in the same tank on an assembly panel mounted on a removable part.

The operability of the proposed reactor and its high technical and economic indicators are confirmed by calculations, physical modeling, test results of prototypes of similar designs. Compared to analogues and prototype, the proposed reactor has reduced steel consumption, losses, reliability, labor costs in manufacturing, and dimensions and weight have been reduced. In the near future it is planned to manufacture prototypes for mass production.

LITERATURE

1. Bryantsev AM "Electric reactor with magnetization." RF patent JY ^O RU 2324251, application: 2006146290/09, 12/26/2006. Published: 05/10/2008.

2. Bryantsev A.M. "Electric reactor with magnetization." RF patent JYO RU 2324250, application: 2006145299/09, 12.20.2006. Published: 05.10.2008.

Claims

CLAIM

An electric three-phase magnetization reactor, the magnetic system of which is made of charged sheets of electrical steel and contains a magnetic circuit with coaxially arranged three upper and three lower vertical rods, on which two-section windings, upper, lower and middle horizontal and two lateral vertical yokes are placed, The horizontal yokes have two middle and two extreme sections, four magnetic shunts in the form of rectangular frames with horizontal and vertical sections, and the horizontal the on-site sections of the shunts are located at the ends of the windings along the upper, middle, and lower yokes, and the vertical sections closing them are located along the side yards, and the reactor also contains controllable semiconductor converters of diodes and resistors and a control system, the windings being connected with a three-phase network and with converters, characterized in that three-winding isolating transformers installed between the converters and the control system in mid-horizon sections are introduced into the reactor For the magnetic yoke of the magnetic core, non-magnetic gaps are made, each magnetic shunt has two additional vertical sections located between the windings, the ratio of the values of the non-magnetic gaps of the magnetic core in the extreme parts of the average yoke Lcr _Ain and the values of non-magnetic gaps in the middle parts of the average yoke A, the _average

1 5 <(Avg.

the ratio between the steel section of the middle sections of the middle jugle 8 _sr. and the cross section of the rods S is within

0.9 <(S _cp.ap. / S) <l, 3,

the ratio between the steel cross section of all other sections of the core S _ap . and the cross section of the rods S is within

0.7 <(S _ap . / S) <0.9,

0.07 <(S _m / S) <0.3.