Method of power takeoff from half-wave power transmission in “electric centre”
FIELD: electrical engineering.
SUBSTANCE: according to the method on the line arranged are additional sources of reactive capacitive power reducing the line inductance n times and increasing the line capacity n times and raising the voltage performance along the ordinate axis by reducing the line wave resistance only.
EFFECT: providing consumers with rated voltage in the “electric center” of the middle part of a half-wave power transmission line operating in the idle mode.
1 cl, 1 dwg
SUBSTANCE: use of the invention: in electrical engineering. According to the invention, input data on voltages, currents and their frequency in a non-homogeneous power transmission line can be obtained through interface units or sensors made in the form of voltage and current transformers or in the form of voltage dividers and alternating current shunts, spectrum analysers and frequency meters. As a result of processing of the input data in the processor there shaped are control signals for correction elements which can be represented by on-load tap changers of power transformers, reactors and three-phase or single-phase current and voltage generating devices such as capacitor banks, three-wire (without the fourth conductor from a neutral of a power supply and load source) consolidated load consisting of a step-down transformer, the connection circuit of primary and secondary winding of which is "triangle/star with an output zero conductor", filters of higher harmonic components of currents and voltages, and an active filter with floating capacitors, which is provided for a single-wire line.
EFFECT: providing coordination conditions for all line conductors, except for superconductors, and a neutral conductor with electrical loads.
SUBSTANCE: device for synchronisation of parameters connected for parallel operation of generators comprises two division devices, two comparators with an actuating element at the outlet, which form jointly the first regulation block, a common subtractor, an amplitude detector connected to the outlet of the reference generator and comprising a differentiator, a subtractor, an integrator, a signal delay element, two multipliers, a block of rooting and two additional amplitude detectors.
EFFECT: increased accuracy of detection of mismatch of amplitudes, frequencies and phases connected for parallel operation of generators and reduced error of synchronisation of these parameters of board network voltage.
SUBSTANCE: invention is referred to the electric power industry, and namely to the improvement in quality of electric energy in power transmission lines with distributed parameters of medium, high and superhigh voltage. A change in primary parameters of a power transmission line in the operation process is related to the change in a sagging value of a linear wire of the power transmission line. For three linear wires composing the three-phase three-wire power transmission line (PTL) (2) placed at poles (1) it is suggested to evaluate sagging by one distance meter (24) operating in real time and placed in a supporting structure of theses liner wires, which unites all linear wires by means of polymer insulators (3). Supporting structures made of the polymer insulators with distance meters are placed at some locations along the whole length of PTL. The distance meters are supplied by an electric energy accumulating battery (20), which, in its turn, receives electric energy from a solar battery (10). As a result of comparison of the values by the processor the actual sagging values for the wire are measured indirectly and considered in a special programme.
EFFECT: invention provides reduced losses of electric energy and increased capacity of PTL.
2 cl, 6 dwg
SUBSTANCE: electric distributing network comprises a feeding transformer substation and receiving distributors interconnected by feeding power transmission lines including at least one electric circuit with voltage of 0.4 kV, at that according to this invention feeding lines are coupled additionally to the circuit with voltage of 0.95 kV. The feeding transformer substation is made with power three-winding transformer 6(10)/0.95/0.4 kV, receiving distributors in the circuit with voltage of 0.95 kV are made as individual transformer substations with three-phase power transformers of 0.95/0.4 kV and/or single-phase power transformers of 0.55/0.23 kV.
EFFECT: improving power supply reliability for consumers and ensuring the rated quality of electric energy.
SUBSTANCE: system contains the directional power relays located on traction substations and by their outputs connected to switch control units, and by inputs - with the evaluators of current of power branches of traction substations and voltage transformers of distributing devices 27.5 kV. Each voltage transformer of the contact network feeders of the traction substation is connected by one terminal of primary winding to the contact network feeder of the traction substation, and the secondary winding terminals - to the voltage comparator, these voltage transformers are connected only to one of feeders of the contact network of each power branch of traction substations, the adjacent switch control units of each intersubstation zones are connected to each other by means of communication channels of switch control units, voltage comparators are connected to switch control units, the switch control units are connected by means of communication channels with the control units switches which are also connected through communication channels with the switches of additional parallel connection points, current evaluators of the power branch of the traction substations are connected by the inputs to the current transformers of the contact network feeders of the traction substations, the additional parallel connection points with switches are connected to contact suspension brackets of the neighboring tracks near places of connection of feeders of distributing devices 27.5 kV to contact suspension brackets of the contact network.
EFFECT: improved quality of electric power in the power supply system.
SUBSTANCE: invention is used in electrical engineering. Matching of four-wire power transmission line, namely, line and neutral wires with electrical load is achieved as a result of compliance with certain conditions involving comparison of actual (which is present in real time at the facility) and reference (determined using the specialised software) load resistance, voltages at the line end and currents supplied to the load. Source data on voltages, currents, and frequencies in the line can be obtained through interface units, or sensors made in the form of voltage and current transformers or in the form of voltage dividers and alternating current shunts, spectrum analysers and frequency meters. As a result of processing of the source the data control signals are generated for adjustment devices, which are represented by constant-voltage regulators of power transformers, without balancers, three-phase devices and single-phase devices that generate current and voltage such as capacitor banks, four-wire (without the fourth wire from the neutral of the power source or load) generalised loads consisting of step-down transformer, which primary and secondary windings are connected as delta/star, filters of higher harmonic components of currents and voltage, the active filter with "floating" condensers designed for the single-wire line.
EFFECT: decrease of losses of electric energy, increase of the line capacity and decrease of distortion of voltage and current curves.
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: network is based on overhead power transmission lines (1), (2), (3), (4) with the voltage of 20 kV, 10 kV, 6 kV and (0.7-0.99) kV respectively. Lines (1), (2), (3) are connected through a single-transformer substation (5) 20(10)(6)/(0.7-0.99)/0.4 kV or 20(10)(6)/(0.7-0.99) kV by a circuit (6) to a transformer (7) winding of the overheard power transmission line (4) with voltage while by the other circuit (8) - to the transformer winding of the overheard power transmission line (9) with the voltage of 0.4 kV. Lines with the voltage of (0.7-0.99) kV are connected to consumers through individual step down pile-mounted transformer substations (0.7-0.99)/0.4 kV or (0.4-0.57)/0.23 kV with a switchgear cabinet of (0.23-0.4) kV. The network 4 is mounted both at non-insulated wires and self-supported insulated wires. The substation (5) is made as a three-phase transformer of 20(10)(6)/(0.7-0.99)/0.4 kV or a double-winding transformer of 20(10)(6)/(0.7-0.99) kV.
EFFECT: improved reliability and economic benefits of distributing power networks for consumers.
8 cl, 1 dwg
FIELD: physics, computer engineering.
SUBSTANCE: invention relates to information-measurement and computer engineering and can be used to generate solutions during real-time operational control of power system modes, based on selecting critical sections and determining maximum allowed overflows on parameters of the current mode of the electrical power system. The system for monitoring the stability margins of an electrical power system comprises a group of random access memory devices, a group of digital sensors, a storage device, a data collection and processing unit, a unit for evaluating the state of the electrical power system, as well as series-connected unit for determining limiting modes, unit for determining critical sections and unit for determining maximum allowed and emergency allowed overflows.
EFFECT: simple design.
SUBSTANCE: invention is used in electrical engineering. According to the method power of induced voltage is determined by calculations or measurements, autonomous power source is formed with potential adjustment of value and phase of compensating voltage, phase wires of the cut off line are connected by earthing wires to the earth loop of the line support at the job site, value of induced voltage is measured by voltmeter at the job site, the adjustable power source with voltage equal in value and with opposite phase to induced voltage is connected between the earth loop of the support and earthing wires, value of residual induced voltage is controlled against readings of voltmeter.
EFFECT: reduction of induced pressure.
2 tbl, 3 dwg
FIELD: electrical energy transmission to stationary and mobile users.
SUBSTANCE: proposed method makes use of ac voltage generator and includes voltage transfer from generator to low-voltage winding of Tesla coil; connection of one of high-voltage winding leads of this transformer to one of output terminals of electrical equipment being fed (load) and setting of resonant oscillations in electric circuit; rectification of high-frequency ac voltage and current of step-up Tesla coil high-voltage winding by connecting internal lead of this step-up Tesla coil winding to high-frequency diode; and transfer of rectified voltage and current to load over single-wire line. As an alternative, high-frequency ac voltage across high-voltage winding of step-up Tesla coil is rectified by connecting internal lead of Tesla coil high-voltage winding to diode-capacitor unit, doubling voltage, and transmitting rectified voltage and current to load over two-wire line.
EFFECT: enhanced effectiveness, reduced loss, enhanced reliability of electrical energy transmission.
17 cl, 13 dwg
FIELD: converter engineering.
SUBSTANCE: proposed voltage regulator designed for symmetrical mode of operation incorporates provision for simultaneous and similar voltage regulation in all three phases with aid of one switching member in the form of transistor switch at output of three-phase diode bridge connected through ac terminals to loose leads of primary windings, one switching member being used for the purpose in unipolar boost voltage circuits or two ones, in bipolar boost voltage circuits.
EFFECT: reduced number of transistor switches designed for periodic connection of primary windings to supply mains.
2 cl, 7 dwg
FIELD: transmission of electric power in electric networks with an insulated neutral.
SUBSTANCE: an antiphase connection of the electric power sources is supposed in the electrical system, which makes it possible to make a four-wire power transmission line at preservation of the same level of transmitted power as via a two-circuit power transmission line with six line wires.
EFFECT: reduced loss of electric power, as well as reduced cost.
4 cl, 4 dwg
FIELD: designing power supply systems for users whose parameters need protection against deviation from specified ratings.
SUBSTANCE: proposed system has power supply and protective gear incorporating protective units and final unit that functions to connect power supply to user upon serviceability check of protective unit conducted by sequential polling, pre-disabling in the process their communication with final unit of protective gear. Polling signal is generated across first protective unit by means of dc voltage supply. Output signal pointing to operation of successive protective unit is used as polling signal of next unit, as preceding-unit polling cancellation signal, and as clear signal. Output signal of next protective unit pointing to serviceability of all units serves as instruction for connecting power supply system to user circuits and for ensuring its operation under normal conditions incorporating function of protection against deviation of output parameters from specified ratings.
EFFECT: enhanced operating reliability.
2 cl, 1 dwg
FIELD: power distribution systems for railways.
SUBSTANCE: proposed system designed to supply railway equipment with ac power at 27.5 kV has pole-mounted traction substations spaced 200 - 240 km apart. These substations supply with power intermediate substations incorporating single-phase transformers and shorting-out switches through two-wire lines installed on contact-system poles. Two three-phase balancing transformers with grounded common point are installed in each pole-mounted traction substation; one of these transformers is operating and other one is stand-by transformer. Two-wire line is sectionalized trough one intermediate substation by means of two switches. Single-phase transformer is connected to each wire of two-wire line either side of sectionalizing switches through tee-junction of disconnecting switches which ensures parallel connection of all pole-mounted traction substations and intermediate substations to traction mains.
EFFECT: reduced number of pole-mounted traction substations and power loss in traction mains.
1 cl, 1 dwg
FIELD: power systems.
SUBSTANCE: one or more electromotive force sources interconnected in parallel through local supply mains are proposed to be additionally introduced and dispersed on territory closer to users with control system incorporating synchronization module, computer, actuating modules, start and stop modules being used to maintain rated characteristics of all electromotive force sources. Provision should be made to transfer excess or backup electrical energy to external supply mains. Proposed power station is characterized in ability of disposing electromotive force sources on right-of-way of secondary land tenure..
EFFECT: enhanced output capacity of power station.
1 cl, 1 dwg
FIELD: electrical and power engineering; power stations using unit-type power supply circuits.
SUBSTANCE: proposed system designed to provide for auxiliary power supply to station power unit, as well as to maintain desired voltage level across switchgear installation and auxiliary power consumers of power unit both in the course of variations in the parameters of the latter and in case of short circuits in station switchgear installation and adjacent supply mains has generator, unit transformer, station switchgear and auxiliary power installations, operating and additional auxiliary-power transformers. Line leads of generator stator winding are connected through unit transformer and operating transformer to switchgear installations and to auxiliary-power installations, respectively. Second winding of additional transformer is connected in parallel with power circuit between secondary winding of operating transformer and auxiliary-power switchgear installation. Primary winding of additional transformer is connected in series with power unit load circuit, that is, this transformer runs under load-specified conditions. Power supply system may be provided with additional auxiliary-power switchgear installation, additional transformer being provided with additional secondary windings. This power supply system may be also provided with current-limiting reactors.
EFFECT: enlarged functional capabilities, enhanced operating reliability.
3 cl, 9 dwg
FIELD: ac power supply systems for flying vehicles.
SUBSTANCE: proposed device has base and base-mounted supply mains protective gear in the form of single- and three-phase protective apparatuses integrated into respective functional buses. There are three distribution buses A, B, C connected to power supplies, each incorporating power terminals for respective functional buses. Single-phase protective apparatuses are disposed in staggered manner relative to adjacent rows of apparatuses and their functional buses are comb-type buses with flexible contact tags abutting against tilted contact strips of protective apparatuses. Functional buses of three-phase protective apparatuses are made of integer flexible insulated wire. Bends at stripped insulation points are clamped by cable lugs for connection to contact strips of protective apparatuses. Each functional bus of both single- and three-phase protective apparatuses is connected through its leads to different power terminals of functional buses related to same distribution bus.
EFFECT: enhanced operating reliability of power supply system, reduced mass and cost of flying vehicle equipment.
1 cl, 4 dwg
FIELD: electrical engineering; current regulation systems for aluminum-industry heavy-power converter substations.
SUBSTANCE: proposed device noted for high working capacity as a whole at varying input parameters and incorporating provision for multiple increase in current regulation precision has three-phase booster transformer, phase-shifting transformer, reactance components constituting three-phase resonance-tuned reactor and three single-phase capacitor units, load, three-phase autotransformer, and supply mains; in addition, at least one voltage selector switch may be introduced in device and at least one of autotransformer windings may incorporate regulation sections; moreover, at least one three-phase controlled reactor may be introduced in device and autotransformer may be provided with additional winding.
EFFECT: enlarged functional capabilities, reduced size and mass of device.
3 cl, 1 dwg
FIELD: power supply systems for consumers disposed at long distances from power centers.
SUBSTANCE: proposed single-wire distribution network that has power supply, three-wire network connected thereto, single-phase step-down transformer, intermediate converter installed on three-wire network submain that incorporates power rectifier bridge whose inputs are connected to three-wire network and outputs, to ripple capacitor, power supply, and primary winding of single-phase intervening transformer one of whose secondary-winding leads is grounded and other one is connected through single-wire line to one of primary-winding leads of single-phase step-down transformer; other lead of the latter is grounded and its primary winding is connected in series with power thyristor assembly whose control input is connected to anode of rectifier diode; cathode of the latter is connected to secondary winding lead of disabling matching transformer whose primary winding integrated with parallel-connected protective diode is inserted in collector circuit of disabling transistor; connected to base of this transistor through current-limiting resistor is output of 2AND gate one of whose inputs is connected to pulse-width modulated generator and to rectangular-pulse generator and other one, to rectangular-pulse generator through inverting component; connected to cathode of second rectifier diode whose anode is connected to secondary winding lead of enabling matching transformer whose primary winding incorporating parallel-connected second protective anode is inserted in collector circuit of enabling transistor whose base is connected through current-limiting resistor to output of second 2AND gate; inputs of the latter are connected to pulse-width modulated generator and to rectangular-pulse generator; secondary-winding second leads of disabling and enabling transformers and leads of non-polar voltage regulator diode are connected to power thyristor assembly cathode.
EFFECT: enhanced reliability of power supply.
1 cl, 1 dwg