SU1251261A1 - Method of controlling four thyristor rectifiers with forced commutation - Google Patents

Abstract

The invention relates to electrical engineering and can be used in control systems on electric conductors. The composition of the alternating current. The purpose of the invention is to increase the power factor in the initial part of the adjustment characteristic when implementing the method of controlling four identical thyristor rectifiers (TB) 1-4. To the secondary windings of transformers 13-16 are connected the corresponding TV 1-4, which are connected through their filters 5-8 with their own loads 9-12. The primary windings of transformers 13-16 are connected between the contact network 17 and ground. The control method of TB 1-4 is that control pulses are generated in the middle of the half period of the network voltage curve. The shift of the rear SRI front control pulses for TV 1 and the front edge for TV 2, uveI (L ts9 g g W

Description

Lichivayut interval conduction to 75 e. hail. Increase the conduction interval to the beginning of the half-cycle for TB 1 and to the end of the half-period for TB 2. After that, increase the conduction interval for each TB 1-4 to 180 e. hail. Moreover, these phase-controlled control pulses form for TV 1 and TB 2 only for odd half-periods, and for TV 3 and TB 4, according to the same algorithm, for even half-periods. Kogf

The invention relates to electrical engineering for use primarily in control systems on AC electric rolling stock.

The purpose of the invention is to increase the power factor in the initial part of the adjustment characteristic when implementing the method of controlling four identical thyristor rectifiers.

On. Fig. 1 shows an electrical circuit comprising four rectifiers controlled by the proposed method; FIGS. 2 and 3 are diagrams of the rectifier voltages and currents in the primary network.

FIG. 1 shows an electric drive circuit containing connectors 1–4, each of which through a corresponding filter 5–8 feeds its load 9–12. Each of connectors 1–4 is connected to the secondary winding of its transformer 13–16. These primary windings transformers are connected between the contact network 17 and ground.

The load 9-12 for the electromotive motion of the single-phase-current composition is a direct current motor, and the dp of an electric rolling stock with asynchronous traction motors is an autonomous current or voltage inverter. x

Turning on and off the fully controlled thyristors of the breakers 1-4 is performed by a control system which is not shown in the diagram.

51261

yes the conduction intervals TB 1–4 for the corresponding half-periods reach 180 e.gard. phase-controlled control pulses form according to the same algorithm dp even half-periods for. TB 1 and TB 2 and for odd half-periods for TB 3 and TB 4. This control method allows one to obtain the shape of the total consumed current curve, which is close to sinusoidal, which determines its efficiency. 3 il.

In the initial part of the adjustment characteristic (fig. 2a), the conductor interval of the rectifier is formed

1 and 2 are from the middle of even half-periods, moreover, at rectifiers I and 3 its

they count in the direction of the end, and in 2 and 4 - in the direction of the beginning of the corresponding half period. After reaching the conduction interval of 73 degrees,

its further increase dp corresponding half-periods. 1-4 are carried out from their middle in the opposite direction to the half-period border (Fig. 2b). Expansion

the conduction intervals in the corresponding half-periods due to the unused part of the half-period (13 electr.config.) are shown in Fig. 2c.

the output voltage (in the second half of the adjustment characteristic), the control algorithm is repeated in accordance with Fig. 2 (a, b, c), only the adjustable conductivity intervals of the top of the targets I and

2 is counted from the middle of even, and for 3 and 4 - from the middle of odd half-periods (fig.Z a, b, c).

This control method allows to obtain the shape of the curve of the total consumed current 1 | - (Fig. 2 and 3), approaching a sinusoidal one.

The proposed method of controlling the output voltage of the drivers provides a higher value of the power factor ee, which

and determines its technical and economic efficiency.

Claims (1)

Invention Formula The control method of four forced switching commutators, consisting in the fact that control pulses are generated in the middle of the half-period of the network voltage curve, increases the conductivity interval up to 75 electr., Dv: helium of the control pulses. for the first miter and front for the second, then increase the conduction interval until the beginning of the half period for the first miter and until the end of the half-cycle for the second, then increase the conductivity interval for each mitel to 180 different II a. Js d  .: IffO F - q | T7 By the fact that, in order to increase the power factor in the initial part of the adjustment characteristic, the above phase-controlled control pulses are generated for the first and second metals only for odd half-periods, and for the third and fourth rectifiers, the phase-controlled control pulses are formed by the same algorithm only for even half-periods, and after the conductivity interval for each respective half-period reaches 1.80 electr., the phase-controlled control pulses form for the even half-periods for the first and second and for odd half-periods for the third and fourth higher times.  art g about. J5 : .z: .c / 2 45 Uft Zx .. Uft J5 / 2 (irt V2f  :: xz5fewz :: BUT. AND - / J y SST tff-t fewz :: ifft and. „ZT ZZEZT t M. / .Sh ./  P 77 // Y7 / 1, U / //// L go about , ten IU / / /./X W / U / Y / / X Ufft J Editor M. Bandura Compiled by .O.Parfenova Tehred o.Gor tvay Order 4423/55 Circulation 631 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 Proofreader A. Obruchar