Actuation method of transformer of traction substation
SUBSTANCE: substation transformer start-up method, at which, first, two input terminals are connected to two phases of a three-phase network at transition of phase voltage of the third phase of the network through zero, and then, the third input terminal is connected to the third phase of the network at transition of linear voltage from two previous phases through zero.
EFFECT: simpler implementation of the method and elimination of additional losses in a three-phase transformer owing to providing accuracy of initial moment of actuation of two phases.
The invention relates to electrical engineering, in particular to systems for industrial, municipal and traction power supply, and can be used in transformer substations, including for railway and urban (trams, trolley buses, escalators) electrified transport.
The known method include three-phase substation transformer on the AC No. 639120 the USSR, published 25.12.1978 in bull. No. 47, which is used as a prototype. According to the method of connecting two phases of the primary winding of the transformer at the time of maximum voltage between them, and then connect the third phase in the transition of the above-mentioned voltage through zero.
The disadvantage of the prototype method is the complexity of the implementation, due to the fact that the maximum voltage between two phases is difficult, especially when the distortion voltage. Modern consumers in industrial and traction power supply, having a highly variable, reactive, non-linear (including valve) character, create input and output transformer substation distortion of currents and voltages. When the distortion voltage having a random character, may be offset or ambiguity extremum, which makes it difficult to control the maximum voltage.
This feature violates accuracy is ü the inclusion of the two phases in the π/2 line voltage and will not provide for the inclusion without surge current, will increase during the transition process. While the subsequent inclusion of the third phase even at the right time (when switching the above-mentioned voltage through zero) will create a new perturbation to the unfinished transition process.
All this does not completely limit the starting current and the duration of the transition process, creating electrical losses, and one-sided bias of the transformer core will increase the magnetic losses.
The objective of the invention is to simplify the implementation of the method and the elimination of additional losses in three-phase transformer by ensuring the accuracy of the initial inclusion of the two phases.
The solution of the task will be simplified implementation of the method and achieved the exact identification of the moment of inclusion in the π/2 line voltage from these two phases. Ease of implementation is to identify the transition phase voltage of the third phase through zero, using nonorgan, for example, a comparator, one input of which is connected to zero. In addition will be completely eliminated additional trigger losses in the transformer.
The solution of this problem is achieved by the fact that the inclusion of the two input terminals to the two phases of three-phase network are produced in the moment of transition of the phase voltage of the third phase of the network through zero.
usnot the proposed method is illustrated in the following description and the accompanying drawings. In Fig. 1 shows a distorted voltages and currents, and when enabled by a known method, and Fig. 2 - distorted voltages and currents and in the inclusion of the proposed method.
Numerical experiments in MatLab found that the accuracy of the inclusion by a known method violated ambiguous extremum voltage, distorted the 5th and 7th harmonics, and the inclusion of the two phases according to the first maximum linear voltage causes a transition currents (Fig. 1), the attenuation of which lasts several tens of periods. The application of this process include the third phase even at a given point in time during the transition line voltage through zero does not eliminate, but rather exacerbates the situation from the steps of the transition process, i.e. not achieved the desired result. In comparison with this, when turning on the other two phases at the time of zero crossing of the phase voltage of the third phase (Fig. 2), almost immediately achieved steady state currents.
Suitable applications are transformer substation systems for municipal, agricultural, industrial power supply and traction power supply systems electric transport.
The method of inclusion of the substation transformer to the input terminals intended for connection to three-phase with the ti and output terminals, intended for connection through traction network to electrificadora transport, first connect the two input clamp into two phases of three-phase network, and then make the connection to the third input of the clamp to the third phase of the network at the moment of transition line voltage from the two previous phases through zero, characterized in that the inclusion of the two input terminals to the two phases of three-phase network are produced in the moment of transition of the phase voltage of the third phase of the network through zero.
SUBSTANCE: invention may be used to create rectifiers for controlled electric DC and AC drives for machines to increase their efficiency, and also on transformation substations for power supply to electrified railway roads, in electric metallurgical and chemical industry to reduce the value of pulsations of rectified voltage and to reduce content of higher harmonic components in an AC curve in a three-phase grid. The proposed five-phase phase changer comprises a three-phase transformer, having three coils of the primary winding, which are connected as a star network, and are connected to the three-phase grid with a zero wire "0", six joined main coils of the secondary windings, one additional coil of secondary winding and taps from turns of the main coils of the secondary windings, which jointly with the output clamp of the additional coil of the secondary winding create a symmetrical five-phase system of voltages. Each main coil of the secondary winding of the transformer is a side of a "hexagon" A, B, C, D, E, F, transforming a symmetrical three-phase system of voltages into a symmetrical six-phase system of voltages, at the same time the additional coil of the secondary winding with its beginning is connected to the unit of the "hexagon" circuit, which is not connected with the main coils of the secondary winding of the phase, on the rod of which there is the additional coil of the secondary winding.
EFFECT: reduced consumption of active materials during replacement of a three-phase group transformer with a three-rod one, improved weight and dimensional indices of a converter, simplified design of a converter and technology of its manufacturing.
SUBSTANCE: drive system for actuation of a tap changer for the purpose of on-load transformer voltage control comprises an electric motor (20), made as capable of connection with a movable part of the specified tap changer for its displacement for the purpose to perform a tap-changing operation. The system comprises an electric converter (33) for connection of a supply source (24) to the specified electric motor (20), and also a device (34) of control made as capable of electric converter control with the purpose to control operation of the motor and thus the specified tap changer.
EFFECT: expanded operational capabilities by provision of ability to adapt to various levels of controlled voltage and to various characteristics of tap changers.
26 cl, 7 dwg
FIELD: electric engineering.
SUBSTANCE: in the transformer machine for alternating current electric rail roads, which contains three-phased traction transformer, having three-rod magnetic conductor, primary winding connected to power network, and secondary winding, phase windings of which are connected to each other, two volt-adding windings, each one of which is positioned on the middle rod of three-rod magnetic conductor and connected by one end to appropriate section of contact network, and by other end - to one of windings of phases of secondary winding, which is positioned on extreme rod of three-rod magnetic conductor. In accordance to the invention, each volt-adding winding is fitted with a voltage regulation device.
EFFECT: creation of transformer machine with voltage management for electric railroads, characterized by high operational reliability due to flexible adjustment of numbers of coils of enabled volt-adding windings.
FIELD: electrical engineering.
SUBSTANCE: proposed transformer set has three-phase traction transformer incorporating three-leg magnetic core, primary winding connected to power circuit, and secondary winding built of two phase windings disposed on extreme legs of three-leg magnetic core; finishing leads of these windings are designed for connection to contact system; in addition it has two voltage boost windings, each being disposed on intermediate leg of three-led magnetic core and connected through one lead to traction rail and through other one, to starting lead of one of secondary winding phases disposed on one of extreme legs of three-leg magnetic core. Each of voltage boost windings is proposed to be provided with voltage regulator. Provision is made for joint or separate voltage regulation for each of two contact-system sections.
EFFECT: reduced current and power loss in contact system due to raising voltage across contact system at constant input power of locomotive, improved balancing of supply mains phase currents.
1 cl, 5 dwg
FIELD: electrical engineering.
SUBSTANCE: novelty is that one more secondary winding is proposed to be introduced in adjustable-voltage transformer set that has three-phase traction transformer incorporating primary winding connected to supply mains and secondary winding whose phase windings are interconnected and are provided with three leads of which two ones are designed for connection to contact system and third one, to traction rail; it also has voltage booster whose primary winding leads are connected to phase b leads of three-phase traction transformer secondary winding and its secondary winding is inserted between starting lead of phase a winding and first section of contact system; additional secondary winding is proposed to be inserted between phase c leads and second section of contact system; each secondary winding of voltage booster is proposed to be provided with voltage regulator.
EFFECT: enhanced quality of electrical energy complying with specified requirements due to minimizing equalizing current occurring in traction network.
1 cl, 1 dwg
FIELD: on-load voltage regulation in power and converter transformers.
SUBSTANCE: newly introduced in proposed method for transformer winding tap changing without opening load current circuit, including voltage checkup, in which control pulses are supplied to thyristors of thyristor switches, each incorporating thyristors connected in parallel opposition inserted in tap circuits of transformer winding are procedures of checking currents carried by thyristors of each thyristor switch, voltage recording when current crosses zero, and changing-over transformer winding taps by applying control pulses to one of thyristors incorporated in respective switch depending on time remaining till voltage polarity is reversed.
EFFECT: enhanced reliability.
2 cl, 8 dwg
FIELD: continuous switching of tap-changing-under-load transformers.
SUBSTANCE: proposed stepping thyristor switch has mechanical stepping selector and load switch. Stepping selector only is disposed in transformer oil tank while load switch incorporating thyristors is mounted in separate case attached to one side wherein it is held in air medium, so that switch thyristors are disposed away from hot transformer oil.
EFFECT: enhanced reliability and service life of switch.
SUBSTANCE: invention is referred to a power supply unit for a line portion related to the vehicle track, which comprises a receiver at the side of the line portion to receive energy transmitted actively through electromagnetic induction by a transmitter of the line portion related to the vehicle track. There is an energy storage unit at the side of the line portion to accumulate energy received by the receiver at the side if the line portion and to supply electric energy notwithstanding time of energy transmission from the transmitter to the receiver at the side of the line portion. The invention includes also a device with the power supply unit as well as method to supply the line portion related to the vehicle track with electric energy.
EFFECT: improved reliability and electrical safety of the power supply devices.
19 cl, 1 dwg
SUBSTANCE: invention is related to the equipment ensuring normal functioning of overhead contact system in conditions of making way to high-speed electric stock (HSES). The overhead contact system insulating coupler and neutral insert for high-speed railway trunk lines powered by alternating current comprises the overhead contact system to the right and to the left from the substation powered by different phases of the traction-feeding transformer. In order to exclude short-circuiting between phases two isolating gaps are set and the section of the overhead contact system between these gaps is not connected to any phase. Stepped active resistances coupled to the incoming and outgoing isolated parts of the overhead contact system connected to the gaps are used as executive bodies of arc-striking protection. The above resistances perform function of stepwise reduction or increase for HSES load current. The reduce load current up to the value, which is not destructive.
EFFECT: HSES making way through the neutral insert without destructive arcing.
SUBSTANCE: present invention is related to low-voltage power supply line for devices along a railway line or an underground line. At that this line receives energy from high-voltage and direct-current overhead line passing at the surface instead of a special power line mounted along the track for this purpose.
EFFECT: reduction of costs and improvement of reliability in operation of the low-voltage line.
5 cl, 3 dwg
SUBSTANCE: invention relates to electric power engineering and may be used in poser supply for consuming equipment located along power lines. Proposed system comprises: (i) at least, one distribution station with first voltage applied to its input to get second voltage at its output. Note here that second voltage is lower or higher than said first one, (ii) multiple components arranged long power line. Note here that said components is supplied with second voltage and comprises network power supply to transform second voltage into third voltage.
EFFECT: simplified production and lower costs.
12 cl, 2 dwg
SUBSTANCE: invention relates to electric power supply for electrified railways. Proposed system comprises rectifier substations, overhead system, track circuit, power dispatcher unit, GLONASS/GPS unit, and current and voltage control units. Note here that every rectifier station is composed of transformer with feeders, current and voltage transducers, and voltage controller. Rectifier substations are interconnected by overhead system and track circuits. Overhead system is connected with power transformers of rectifier stations. GLONASS/GPS unit, current and voltage control units are installed at rolling stock. Besides, proposed system comprises unit OR and power accounting device mounted at every rectifier station and every rolling stock. GLONASS/GPS unit is connected to AND unit whereto connected are power accounting device, current and voltage control units.
EFFECT: higher accuracy of power consumption accounting.
SUBSTANCE: electric supply system for electric railway is suggested. Substation for electric railway contains transformer (3) to receive electric energy from AC electric line (2), rectifier (4) connected to transformer (3), power supply line (5) connected to rectifier (4) and nickel-hydride battery (8) as DC power supply, where nickel-hydride battery (8) is directly connected to power supply line. Electric supply system can also contain device for accumulating and supplying electric energy containing nickel-hydride battery connected directly to power supply line and installed out of substation site.
EFFECT: providing stability of transport facilities performance and lowering thermal losses in electric supply system.
20 cl, 20 dwg
SUBSTANCE: invention relates to electrified railways. Proposed system comprises AC traction substations, switchgears, catenary sections, rail circuits, section pillar made up sections of first and second buses, bus switch and single-pole feeder switches, and traction loads. Traction substations are interconnected via switchgears and catenary sections connected via feeder switches to bus first and second sections interconnected via bus switch. One output of traction loads is connected to rail circuits while their another output is connected to catenary sections. Three-pole bus switch features series interconnection of poles. Pure diverter is connected in parallel to one pole of bus switch set to sequential operation of poles in disconnection starting from pole with pure diverter and ending by poles without pure diverters, and, on the contrary, in connection, set to sequential operation of poles starting from pole without pure diverter and ending by poles with pure diverters.
EFFECT: longer life of section pillar bus switch.
SUBSTANCE: proposed configuration includes: line towers, brackets for attachment of two insulators in line at base angles of imaginary spatial equilateral triangle with sides increased to minimum tolerable convergence.
For balancing said linear electric parameters, six-step cross bonding of wires-phases is used with wire-phase turn through 60° at every tower and gyration of wires over entire length of the line. Geometrical arrangement of wires at said towers at angles of imaginary spatial equilateral triangle is performed by means of alternating-height different-length brackets with suspended insulators for wires-phases to be secured thereat.
EFFECT: reduced electromagnetic interferences.
SUBSTANCE: invention relates to electrified railway transport and aims at perfecting overhead power supply circuits. Device serves to connect, a least, one single-phase line 4 supplying overhead contact wire of railway track section to three-phase power supply line 1. At least, one transformer 2 has its primary connected with power supply line 1 and its secondary connected with, at least, one single-phase power supply line 4 and grounding point 10. Note here that balancing device 8 is connected with, at least, one signal-phase power supply line 4 and grounding point 10.
EFFECT: reducing undesirable asymmetry of currents in power supply circuit.
9 cl, 4 dwg
SUBSTANCE: invention relates to power supply of electrified railways and may be used in single-phase AC system with frequency of 27.5 V and frequency of 50 Hz. Proposed compensator comprises measuring current and voltage transformers, primaries of said transformers are connected with output windings of traction transformer connected to automatic switchgear. Secondaries of said transformers and output of perfect time system are connected to appropriate inputs of traction circuit parameters metre. First, second, third and fourth outputs of the latter are connected to inputs of memory unit, unit to compute cosφ and tgφ, unit to determine harmonic components in every phase, respectively, and with first input of the unit computing compensation parameters for every phase. Second and third inputs of the latter are connected to output of the unit to compute cosφ and tgφ and output of the unit to determine harmonic components in every phase.
EFFECT: higher efficiency of traction substation.
FIELD: equipment of electrified railway roads.
SUBSTANCE: apparatus includes pickup of harmonic components of thrust electric current arranged in influencing contact circuit. Unit for processing signal includes n-link thrust electric current selector; first n-link unit of phase shifting members; first n-link unit of phase shift regulators; first n-link unit of scale amplifiers with scaling factors Ksc(comp) and mixing unit. Feedback circuit includes pickup for measuring harmonic components of compensating electric current of screening wire; n-link selector of compensating electric current; second unit of phase shifting members; second n-link unit of phase shift regulators; second n-link unit of scale amplifiers with scaling factors Ksc(m)selected according to relation Ksc(comp) - Ksc(m) = 1. Control inlet of controlled electric current source is connected with outlet of mixing unit. Said source is connected in series with grounded-end screening wire placed between contact circuit and line subjected to influence. Novelty is second feedback circuit including pickup for measuring harmonic components of induced noise; n-link noise selector and n-link unit for measuring amplitudes of harmonic components of noise for detecting their fluctuation in comparison with preset values.
EFFECT: improved protection of communication lines adjacent to thrust circuit due to correction of control algorithm according to real value of noise in adjacent communication line.
1 dwg, 1 ap