SU1534625A1 - Device for regulation of power of single-phase transverse capacitance compensation unit - Google Patents

Abstract

This invention relates to electric power industry and can be used in unbalanced load grids. The purpose of the invention, an increase in the efficiency of functioning, is realized by controlling and regulating not only by the reactive component, but also by current unbalance. This is achieved by the fact that the current consumed by the load of the lagging phase is fed to the input of the reactive power converter 10 without the current of the compensating device, since transformers 2, 3 current included in the difference of currents. The outputs of active power converters 8 and reactive 9 and 10 receive currents proportional to the respective powers at the connection points of transformers 2 and 3. The current values obtained at the outputs of converters 8 to 10 are summed in adder 11, the output of which is U _P = K ( 2Q _OM + 1 / 2Q _ON + √3 / ^2. P _^ON). Comparator 12 compares U _P ≥K ^. Q _K , where Q _K is the power of the compensating device. 1 il.

Description

The invention relates to electrical power engineering and is used in traction with an asymmetrical load, in particular in an electrified iron to ac electric power supply system.

The purpose of the invention is to increase the efficiency of the device,

I The drawing shows a functional diagram of a device for controlling the power of a condenser unit (CI).

Transformer of t bevy substation

feeds 27.5 kV busses through the transformers of lagging phase 2 and advanced phase 3; a busbar (to lagging phase) is connected to a transverse capacitive compensation unit, KU, consisting of a capacitor bank with a reactor 4, a control unit 5 and a current transformer 6. The control unit 5 is made on vacuum switches with control equipment. The voltage transformers 7 are connected to 27.5 kV buses (to the phases) Lagging and leading and to the ground loop. The primary and secondary windings of the voltage transformers 7 are connected in an open triangle. The voltages on the secondary side of the transformers 7, the voltages UA, UB, Uc, are applied to the measuring transducers. The transformers 3 are connected measuring transducers of active power 8 and reactive power 9. A second transducer of reactive power is connected to transformers 2 and 6. The control law further implements the adder 11 and the comparator 12. The switch 13 serves to switch off the short-circuit current of the capacitor.

The device works as follows.

At the output of converters 8-10, we obtain currents proportional to the respective powers at the connection points of current transformers 2 and 3. At the same time, the current consumed by the load of the lagging phase without the current of the compensating device enters the input of the converter 10, which is achieved by switching on the current transformers 2 to the current difference. The output of the converters 8-10 values

  K, - Rop; 1h - K4-Qon;

  Qor

where rop is active power load ahead of the phase; Qon - reactive load power of the advanced phase; QOT is the reactive power of the lagging phase load, summed in adder 1, the output of which is the value

IR K (2QOT + - - Qon +),

where K is the proportionality coefficient,

Comparator 12 compares 0.

Up KQ ,,.

Where QK is the power of the compensating device.

5 When an inequality is fulfilled, a command is issued to turn on the compensating device by the control unit 5, and if the inequality is not fulfilled, the device is turned off,

0 The condition for switching on the compensating device is the minimum value of the load at which equality of losses occurs with the presence and absence of compensation.

5 The efficiency of the device for controlling the power of a one-phase installation of transverse capacitive compensation is increased by reducing the losses in the networks due to the combination of reactive power compensation and load balancing.

Formula of invention

A device for controlling the power of a single-phase transverse capacitive compensation unit connected to a lagging phase of a traction substation of electric AC railways, comprising a control unit, current transformers of a trailing phase of a traction transformer, and a transverse capacitive installation

compensation, the secondary windings of which are included in the difference of currents, characterized in that, in order to increase the efficiency of operation, it is equipped with a transfer51

an advanced phase current generator for a traction substation, two voltage transformers with an open triangle connection circuit, a measuring transducer of active power, and two reactive power transducers, an adder and a comparator, the first terminals of the primary windings of the voltage transformers are connected to the lagging and to the advancing phases, respectively, the second grounding terminals, the first inputs of the measuring transducer of active power and the first reactive power converter p Connected to the secondary area 346256

a coil of the transformer of the advanced phase, and the input of the second measuring transducer of reactive power -. is connected to the difference between the currents of the secondary winding of the current transformer, the lagging phase and the secondary winding of the current transformer of the installation of transverse capacitive compensation, IQ the secondary windings of the two voltage transformers are connected to the second. the inputs of three transducers, the outputs of which are connected to the input of the adder, the output of which 15 is connected to the input of the comparator, and the output of the comparator is connected to the control unit.

Claims (1)

The device operates as follows. At the output of converters 8-10 we obtain currents proportional to the corresponding capacities at the connection points of current transformers 2 and 3. At the same time, the current consumed by the load of the lagging phase without the current of the compensating device is supplied to the input of the converter 10, which is achieved by turning on the current transformers 2 and 6 by the current difference. The values obtained at the outputs of the converters 8-10 A device for controlling the power of a single-phase transverse capacitive compensation installation, _ included in the lag phase of the traction sub50 of the AC electric railway station, comprising a control unit, current transformers of the lag phase of the traction transformer and transverse capacitive installations 55 compensation, the secondary windings of which are included in the current difference, ό characterized in that, in order to increase the efficiency of operation, it is equipped with a current transformer of the leading phase of the traction substation, two voltage transformers with an open triangle connection circuit, an active power measuring transducer, and two reactive power transducers, an adder and a comparator, the first terminals of the primary windings of voltage transformers connected to the lagging and leading phases, respectively, the second leads are grounded, the first inputs of the active power measuring transducer and the first reactive power converter are connected to the secondary winding of the leading phase current transformer, and the input of the second reactive power measuring transducer5 is connected to the current difference of the secondary winding of the current transformer, lagging phase and the secondary winding of the transformer current transverse capacitive compensation, 10 secondary windings of two voltage transformers connected to the second input odes of three measuring transducers, the outputs of which are connected to. the input of the adder, the output of which 15 is connected to the input of the comparator, and the output of the comparator is connected to the control unit.