Device for voltage control
SUBSTANCE: voltage control device comprises of a three-phase transformer. The primary winding of each phase of the transformer includes series-connected network and control part, wherein the first outputs of the control part are connected to the output of the network part in each phase. Thus, a common point is formed. The second outputs of the control part are connected to the first outputs of an uncontrolled reactor of each phase. The second outputs of the uncontrolled reactors of all three phases are interconnected forming the first neutral. The first outputs of thyristor keys are connected to the common connection point of the control and network parts of the first and second phases. The second outputs of the thyristor keys of the first and second phases are combined together to form the second neutral, to which the common connection point of the network and control parts of the third phase primary winding is connected.
EFFECT: simplification of design, improvement of control characteristics and increase of reliability.
3 cl, 4 dwg
SUBSTANCE: in transformer winding taps switching unit the transformer is made with two branches of the split winding with low- and high-voltage taps, thyristors are joined into two valve groups with opposite conductivity directions and interconnected by two outputs, with a phase lead of the supply circuit. The valve group with one conductivity direction is coupled but its other outputs to taps of one branch of the split winding while the valve group with opposite conductivity direction is coupled to the other branch of the split winding.
EFFECT: ensuring voltage regulation under load, reducing value of switching extra currents of the transformer winding control stage.
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.
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: group of inventions is related to above-ground structures for tethered aircraft. The first version of a power supply method for an aircraft with a tether line is characterised by the fact that power supply from the ground is carried out with high voltage of 0.1-10 kV by converting the voltage of the ground power supply source from 12-380 V to 0.1-10 kV and then transmitted through a transmission line with the further conversion of the voltage from 0.1-10 kV to 12-380 V. The second version is characterised by transmission of power from the ground in a resonant way at the high frequency of 1-25 kHz by the conversion of the ground surface in the voltage and frequency from 12-380 V to 0.1-10 kV, 1-25 kHz and transmission through transmission lines with the further conversion of the cable line voltage from 0.1-10 kV up to 12-380 V. Each version of the power supply device is characterised by the usage of the respective voltage converters.
EFFECT: group of inventions is oriented to the increase of the power supply range and altitude.
4 cl, 2 dwg
SUBSTANCE: invention relates to the electrical engineering. The device is intended for improvement of electric energy quality in regard to unbalance level in power networks with voltage of 0.4kV. It eliminates voltage unbalance due to vector subtraction of zero-phase-sequence voltage from voltage for all the three phases; to this end each of three groups of in-series secondary windings of step-down single-phase four-winding transformers with transformer ration equal to three is connected in series to wire of the respective phase so that voltage added to the line is subtracted by geometric vectors from voltage of the respective phases. The device is connected to the line break; it may be used for improvement of electric energy quality both for individual devices and their groups in regard to unbalance level. The balancer consists of three step-down single-phase four-winding transformers (1) with one primary (2) and three secondary (3) windings, input terminals (4), output terminals (5).
EFFECT: simplification of design, improvement of reliability and efficiency.
SUBSTANCE: device comprises network terminals, three fast-operate fast-release voltage relays with closing and opening contacts, seven repeater relays per a phase with closing and opening contacts, three phase-recovering capacitors, three phase-shifting chokes, three phase-compensating capacitors, terminals for the connection of a three-phase load and a power supply source. The voltage relays are coupled to phase voltage of the respective phases in the network, the phase-recovering capacitors are coupled to linear voltage, at that each of the capacitors is connected in series to an opening contact of the repeater relay of the respective phase, each of the phase-shifting chokes is shunted by the closing contacts of the first and second repeater relays of the respective phase and by the in-series closing contacts of the third and fourth repeater relays of the respective phase, the repeater relays are connected to the negative output of the power supply source directly and to the positive output through the closing contacts of the voltage relay respectively. Each phase-compensating capacitor is shunted by the closing contacts of the fifth and sixth repeated relay of the respective phase and the phase-shifting capacitor of each phase is coupled between the same phase of the network and the phase next to the retarding phase through the opening contact of the seventh repeated relay of the respective phase.
EFFECT: faster operation and bigger power of the device.
1 tbl, 1 dwg
SUBSTANCE: in the method which assumes switch-over, at least, of part of single-phase loads to the least loaded phase for each switched-over single-phase load in the place of its connection to the line the values of active power corresponding to each phase voltage and current of zero wire of the line without considering the current of single-phase load are determined, and as the least loaded phase the line phase with the maximum value of the absolute value of active power is accepted the sign of which is opposite to the sign of active power of the most loaded phase. The device implementing the method contains the switching unit (1), four inputs (7, 8, 9 and 10) which are inputs of the device and are used for connection to phase wires F1, F2, F3 and zero wires N of the line, and two outputs (11) and (12) of the switching unit are used as the device outputs and are intended for connection of the single-phase load. The device also contains the current sensor (3) connected to zero wire N of the current line, and the first (4), the second (5) and the third (6) phase voltage sensors connected to device inputs, and also the unit 2 for determination of the least loaded phase the output bus (20) of which is connected to the control input of the switching unit 1. The unit (2) for determination of the least loaded phase contains the multichannel analogue-digital converter (17) connected to the input (19) unit (18) of digital signal processing. Inputs of the multichannel analogue-digital converter (17) are connected to the first (13), to the second (14), to the third (15) and to the fourth to inputs of the unit (2) of determination of the least loaded phase the output bus (20) of which is the output of the unit (18) of digital signal processing.
EFFECT: decrease of disbalance level at which the balancing of phase currents is performed, simplification of implementation and improvement of operational reliability.
5 cl, 2 dwg
SUBSTANCE: invention is used in electrical engineering. The method consists in following stages: formation of the component of the positive phase sequence system, intended for power supply, formation of the component of the negative phase sequence system, intended for power supply, superposition of the component of the positive phase sequence system and the component of the negative phase sequence system with obtaining of supply current, and supply of such composite current into a three-phase mains.
EFFECT: decrease of non-symmetry in three-phase mains.
12 cl, 5 dwg
SUBSTANCE: invention is used in electrical engineering. The device represents an earthing bipole - a tracking width-modulated voltage converter (a tracking PWM converter) attaching the neutral of the network feeding transformer to earth and forming lagging current for compensation of leading capacitance current of single-phase fault to earth, as well as a neutral current sensor, a network voltage transformer, a clock signal generator for measurement of network capacity and a calculation unit for determination of the required admittance of the above bipole. In addition to a common set of functional units, the tracking PWM converter is equipped with a current setting unit, the inputs of which are represented by neutral voltage and the required admittance, and the output of which is represented by current demand supplied to the current control input of the tracking PWM converter, and transfer function of the current setting device provides for lagging phase shift of about 90 degrees on network frequency.
EFFECT: improving quick action and enlarging functional capabilities.
9 cl, 46 dwg
SUBSTANCE: invention relates to electric engineering. The invention claims a three-phase balancing device where a three-phase three-leg transformer contains windings connected in an opposite staggered way. Free leads of the first windings are connected to output terminals and free leads of the second windings are connected into a common zero point to couple phase loads. In each phase there is one or two in-series voltage adding windings coupled through a two- or three-position switch in sequence with load at the side of the supply mains.
EFFECT: provision of the phase voltage balancing.
SUBSTANCE: control method for shunting of power supply units includes the following steps: measurement of the first three-phase output eclectic signal; calculation of the first direct and reverse sequences of the first three-phase output eclectic signal; generating of the preset components for direct and reverse sequences of phases in order to perform automatic compensation for the components of the first direct and reverse sequences thus outputting components of the second direct and reverse sequences; summing-up of the second direct and reverse sequences and output of the second three-phase output eclectic signal in the preset mode.
EFFECT: reducing output voltage ripple.
10 cl, 10 dwg
SUBSTANCE: invention is related to the field of electric engineering and power electronics and can be used for manufacturing of HV three-phase alternating current generating systems for aircraft. The suggested three-phase alternating current generating system with voltage inverter contains a three-phase synchronous generator, a static electric energy transducer based on a three-phase bridge rectifier which inputs are connected to outputs of the synchronous generator, two filter capacitors in the direct current link connected in-series and switched on in parallel to the output terminals of the rectifier and a three-phase bridge voltage inverter which inputs are connected to the rectifier outputs and outputs are connected to inputs of three low-frequency LC filters; a neutral load wire of the generation system is connected to the average point of filter capacitors in the direct current link; an inductance coil is connected by its one output to the neutral load wire of the generation system and by its other output to the neutral wire of the stator three-phase winding of the synchronous generator.
EFFECT: reducing electric losses in elements and improving efficiency ratio of the system as a whole.
SUBSTANCE: voltage stabiliser for a power supply system, which stabilises load of active power, comprises the first AC-DC and DC-AC converter to convert between AC power and DC power; and a nickel-metal-hydride battery located between and connected to a high-voltage cable at the DC side of the first AC-DC and DC-AC converter and a low-voltage cable at the DC side of the first AC-DC and DC-AC converter.
EFFECT: reduced mass and dimension parameters of a device.
10 cl, 17 dwg
SUBSTANCE: in the mains voltage control unit the transformer primary winding connected through the reverse polarity switch with the adjusting winding (secondary winding) of the transformer and placed with it on the same magnetic conductor is installed in the device with a possibility of interaction with the winding of the voltage measuring transformer connected to the electric drive-connected controller. The device contains two additional regulators which are identical with the first one. Regulators are connected to the three-phase voltage network with formation of the connection circuit designed as a full triangle as it is indicated in the application materials.
EFFECT: improved reliability.