Device for single-phase automatic repeated connection of ultrahigh voltage lines
SUBSTANCE: device comprising serially connected reactor switches and shunting reactors, neutral of which includes parallel compensating reactor and breaker, capacitor batteries are additionally connected serially with shunting reactors in each phase from the side of neutral leads, shunted with switches.
EFFECT: reliability improvement.
The invention relates to techniques for the transmission of electricity alternating current, namely the transmission of ultra-high voltage (VSS).
Known apparatus for implementing a single-phase automatic reclosing (main electric networks) lines VSS (Hasibar R., Legate A.S., J. Brunke, W.G. Peterson - The Application of High-Speed Grounding Switches for Single-Pole Reclosing on 500 kV Power Systems (Application of high-speed bypass phases at the main electric networks in the transmission 500 kV). - IEEE Transactions on Power Apparatus and System, Vol.PAS-100, No.4, April 1981. - P.1512-1515.), containing shunt switches at both ends of the line, in the pause mode, the main electric networks to sexonthebeach emergency phase ends of the line and thereby reduce to acceptable levels the current arc is sustained.
The disadvantage of this device is its high cost.
It is also known a device for the implementation of the main electric networks of lines VSS, taken as a prototype (NAS, Useraccess, Snejanka. The use of compensatory reactors to facilitate main electric networks of high-voltage lines. // Electric station, 1975, No. 12. - S-72, figure 1). A device for implementing main electric networks in the line contains a shunt reactors connected to the line through the reactor switches. Single-phase short-circuit alarm off phase linear circuit breakers and neutral shunt reactors provides for the inclusion of compensation react the RA. The inclusion of the compensation reactor is by turning off the switch that bypasses the compensation reactor in normal mode. As a result, in the pause mode, the main electric networks is compensation uid tank line and correspondingly decreasing the current feed.
The disadvantage of this device is that the compensating reactor provides reduced during pause main electric networks of the electrostatic component of the current recharge and has no limiting effect on the electromagnetic component. At the same time during the dynamic transition in the pause main electric networks is an increase in the angle between the EMF adjacent systems, and accordingly, in the current arc recharge becomes the defining electromagnetic component. When the angle between the EMF adjacent systems in the range δ0÷δ0to +40° (δ0- the angle between the EMF in the source mode)that, as a rule, takes place, the electromagnetic component of the current recharge is crucial, and the total current recharge reaches 70-90 A. According to the experimental data (Useraccess. The generalization performance data efficiency of the main electric networks VL VSS and experimental data of the time of arc extinction recharge. // Electric station, 1989, No. 3. - P.65-72) when such currents feeding the duration of a pause main electric networks should be 1.8 to 3.0, and when currents in excess of 90 A successful repayment augustinowicz unlikely.
The task of the invention is the reduction of electrostatic and electromagnetic components of the current feed in order to ensure a successful main electric networks.
This object is achieved in that in the known device, containing series-connected reactor switches and shunt reactors, in a neutral position which is parallel to the compensating reactor and a switch in series with shunt reactors in each phase from neutral conclusions connected capacitor Bank, the device is activated switches.
Figure 1 shows the structural diagram of the proposed device. Figure 2 presents the dependence of the current recharge and its components from the divergence angle between the EMF adjacent systems during pause main electric networks.
The device (1) for the implementation of the main electric networks of the line 1 contains shunt reactors 2, is connected to the line circuit 3, the compensating reactor 4 with parallel switch 5 and connected in series with shunt reactors 2 batteries capacitors 6, continuely switches 7.
The device operates as follows. In the normal mode in the case of single-phase short circuit 8 emergency phase line 1 off line switches 9, after which there is a connection compensatory re ctor 4 by turning off the switch 5 and the commissioning of capacitor Bank 6 by turning off the switch 7 in phase, same with the emergency phase of the line.
To substantially reduce electromagnetic component of the current recharge and respectively of the total current to values of less than 40 A, in which is provided a successful main electric networks for 0.6 to 0.8 seconds, the resistance of the capacitor Bank should be 30-40% of the resistance of the shunt reactor. Otherwise, the arc current recharge will exceed the required value of 40 A. the capacity of the capacitor battery is relatively small and does not exceed 2-3% of the power shunt reactor.
Figure 2 illustrates the effective reduction of the electromagnetic component of the current recharge and respectively of the total current flow in the range of 40 A to line 750 kV with a length of 450 km when combined compensation of the reactor and capacitor Bank, the resistance of which is assumed to be 35% of the resistance of the shunt reactor. The value of the electrostatic component of the current recharge is also reduced.
Thus, the device containing series-connected reactor switches and shunt reactors, in a neutral position which is parallel to the compensating reactor and switch, and containing in series with shunt reactors in each phase from the neutral terminals on the capacitor Bank, the device is activated switches, allows to reduce electromagnetic who itnow and electrostatic components of the current recharge, that ensures successful main electric networks.
A device for implementing single-phase automatic reclosing of ultra-high voltage lines containing series-connected reactor switches and shunt reactors, in a neutral position which is parallel to the compensating reactor and the switch, characterized in that it introduced a battery of capacitors, the device is activated switches and installed in each phase in series with shunt reactors from neutral conclusions.
SUBSTANCE: improved efficiency of method implementation is achieved due to multi-phase system balancing against specified phase, or phase with load current close to mean current, or less loaded phase defined as reference phase. By the method, balancing is implemented by generation of pre-formed currents by means of additional power source in each of remaining (n-1) phases, so that in each balanced (n-1) phase of the main n-phase network, the geometrical sum of currents generated in balanced phase and with load current is equal modulo to current in reference phase, and angle formed by the current of reference phase and total current of balanced phase following the reference phase at forward sequence of phases, as well as between total currents of neighbouring (n-1) balanced phases is equal to electrical degrees.
EFFECT: improved efficiency of multi-phase system balancing due to increased response and simplified implementation, extended application sphere, improved economy.
SUBSTANCE: method consists in generation by means of additional power source to each of the rest (n-1) phases of currents, which are pre-formed so that in each adjustable (n-1) phase of the main n-phase network the geometrical sum of currents - generated to adjustable phase and with current of its load can be equal as to current modulus to the current equal to current in reference phase, and the angle formed with the current of the latter and with total current of adjustable phase following the reference one at forward sequence of phases, as well as between total currents of neighbouring (n-1) adjustable phases can be equal to electrical degrees. At that, power takeoff to the above additional power source is performed from combination of at least two minimum loaded phases which are pre-determined by the condition of decreasing asymmetry in adjustable n-phase system.
EFFECT: increasing quick operation, economy, simplifying the implementation and enlarging application range.
SUBSTANCE: balance-to-unbalance traction-feeding transformer includes three-leg core, three-phase symmetric primary winding and three-phase secondary winding. Secondary winding is connected as per three-rayed zigzag scheme, each ray of which consists of two in-series connected similar windings located on different core legs. Each of the windings of one of the rays has voltage which is 2.5-3.0 times less than that of each of the windings in two other rays. Transformer is converter of three-phase voltage into symmetric two-phase one with phase displacement angle between voltage vectors, which is close to 90°.
EFFECT: simplifying the design and economy of materials.
FIELD: electrical engineering.
SUBSTANCE: invention relates to electrical engineering, and can be used for phase-to-phase distribution of current in magnetically unstable three-phase signals, for example for neutralisation of zero-sequence harmful effects on current feed circuit in three-phase AC-to-DC and DC-to-AC voltage transformers. Proposed device comprises the transformer with its two phase windings connected, each by one output terminal, to zero input terminal, while their other output terminal is connected to appropriate phase input terminal. The transformer comprises two magnetic cores with phase windings connected in series and furnished with central tap. The said windings have their central and extreme free terminals connected to zero and common phase input terminals, respectively. Note here that central output terminal divides the number of turns in each phase windings into unequal parts, smaller ones being connected to opposing phase input terminals.
EFFECT: possibility to use two single-phase transformers with various-shape magnetic cores instead of three-phase transformer.
FIELD: electrical engineering.
SUBSTANCE: invention relates to electrical engineering and may be used for hardware designing to improve quality and reduce voltage and electric power losses, when such power is transmitted in three-phase four-wire electric networks due to reduction of anharmonicity and asymmetry. Protection device generates 150 Hz frequency current from phase currents. This current is immediately introduced to harmonics 3 current of neutral working wire in opposite phase.
EFFECT: compensating highest current harmonics flowing along neutral conductor.
2 cl, 2 dwg
SUBSTANCE: invention concerns current power transmission equipment, particularly high-voltage power transmission. Device includes reactive shunts connected by reactive switches to line, with additional special reactive shunts connected to the line in star network pattern with unearthed neutral conductor.
EFFECT: enhanced shunt compensation of power transmission line in low load mode, stability and reliability in elimination of single-phase short circuits at single-phase reclosing.
FIELD: power production.
SUBSTANCE: when non-sinusoidal shape of supply voltage is decreased, electric power is distributed between electronic devices distorting the shape of supply voltage and electronic devices improving the shape of supply voltage during the semi-wave of supply voltage. Device is connected in parallel with consumers introducing distortions of voltage shape. Main voltage is supplied to the device input. Device includes serial connection of phase-shifting chain, control pulse shaper, dc power supply and power switcher, which connects consumers improving the shape of supply voltage to the mains at a certain period of time.
EFFECT: improvement of supply voltage shape and simplification of device design.
2 cl, 4 dwg
FIELD: electric engineering, possible use for powering various equipment.
SUBSTANCE: the balancing three-phased to one-phased transformer of alternating voltage contains input and output contacts, to which a transformer is connected which has primary windings in all three phases and two secondary windings in phases A and C. Primary windings are connected in a "zigzag". Windings of phases A and B, B and C, and also C and A are connected respectively. Secondary windings in phases A and C are coupled oppositely and are connected to output contacts.
EFFECT: reduction of stabilized power and asymmetry of primary currents and voltages.
FIELD: electric engineering, possible use in power circuits of various equipment.
SUBSTANCE: three-phased balancing device contains input and output clamps of powering networks. To output clamps, three-phased transformer is connected, primary windings of which are oppositely coupled in a zigzag. In accordance to the invention, between input and output clamps of powering network, first three-phased automatic switch is coupled, having an independent release. Serially with primary windings of three-phased transformer, second three-phased automatic switch is coupled. As zero contact for connection of phase loads, zero contact of primary windings of three-phased transformer, coupled oppositely in a zigzag, is used. Control block is connected serially to independent release, coupled between output clamp of one of the phases and zero contact of powering network, and ensures supply of voltage to independent release and activation of first automatic switch on disabling of second automatic switch.
EFFECT: increased reliability when powered from three-conductor or four-conductor powering network.
FIELD: electrical engineering.
SUBSTANCE: proposed method used to enhance quality characteristics of electrical energy supplied to users susceptible to impact of negative factors of electrical-energy higher harmonic components includes generation of higher harmonic components of current in network which are acting in phase opposition relative to higher harmonics of supply mains.
EFFECT: enhanced quality characteristics of electrical energy supplied to users.
1 cl, 3 dwg
SUBSTANCE: device is designed for serial connection to consumer to be protected over booster transformer by two switches, thyristor converter to which absorbing condenser is connected forming power damper for power flow control, operating by utilisation of power stored in charging device in DC circuit. Device is intended for generation and supply of additional voltage with specified amplitude, frequency, phase shift angle, in amount of difference between nominal and actual voltages, to power consumer in order to mitigate short-term dips and allows for maintenance of power consumer voltage during liquidation of power supply failures. Device supplies compensated voltage formed by pulse-width modulation algorithm and adjusted dynamically over thyristor control circuits by converter fed by charging device in DC circuit.
EFFECT: power consumer protection against voltage dips during short-term power supply failure, improved reliability of consumer operation, prevented spread of network crashes.
FIELD: electrical engineering.
SUBSTANCE: invention relates to electrical engineering and can be used for power transmission line (PTL). In compliance with this invention, automatic repeated switching-on of PTL is carried out in compliance with the line diagnostics positive result. In compliance with proposed method, PTL state diagnostics is performed by receiving and analysing continuous high-frequency signals at every phase. Aforesaid signals comprise at least one informative indication of PTL serviceability or apparent failure. Note that HF signal reception and analysis are performed on one end of the line. Note also that informative indications are formed proceeding from inherent and condition resistances at various frequencies.
EFFECT: higher probability of successful switching on.
FIELD: electric engineering.
SUBSTANCE: according to the invention, if current supplied to the customer is measured as overcurrent, the heat amount corresponding to the measured overcurrent is calculated and transmitted to the heat amount control unit before the supplied power is disconnected. The above-mentioned control unit continues to operate after de-energising using battery power. When power supply is restored via automatic switch, further overcurrent takes place. The residual amount of heat in electrical circuit is analysed based on the data stored in heat amount control unit and time elapsed. Finally, variable time of emergency trip delay for automatic switch is defined.
EFFECT: increased accuracy and easiness of device.
11 cl, 4 dwg
SUBSTANCE: invention relates to the filed of electrical power engineering and is to be implemented in protective relay and automation equipment for control over connection of three-phase power transmission lines (PTL). The proposed mode envisages the sequence of operations being as follows: phase 1 connection, phase 2 and phase 3 voltages measurement, check-up of each of the voltage values measured for being lower than the first reference value; in case the check-up yields positive results one proceeds with phase 2 connection, phase 3 voltage measurement, check-up of the phase 3 voltage value measured for being lower than the second reference value; in case the check-up yields positive results one proceeds with phase 3 connection; in case any check-up yields negative results or there is a protective relay signal for disconnection of the currently connected phase the subsequent phases remain unconnected and the previously connected ones become disconnected. After connection of phase 1 and measurement of phase 2 and phase 3 voltages one additionally performs check-up of each of the voltage values measured for exceeding the third reference value. The first and the second reference values are taken to be equal to 75-85% of the rated phase voltage value; the third reference value is taken to be equal to 5-15% of the rated phase voltage value.
EFFECT: elimination of the risk of interphase fault close-in of a line having all its phases disconnected combined with the mode realisation simplification.
5 cl, 1 dwg
SUBSTANCE: method for quenching of arc of single-phase earth fault, in pause of "ОАПВ" of power transmission line, with shunting three-phase reactor and single-phase grounding reactor in neutral of its power winding shunted with switch in normal mode, differs by the fact that as shunting reactor phase-controlled reactor with magnetization is used, the secondary control winding of which, connected as delta, in cycle of "ОАПВ" pause together with unshunting of grounding neutral reactor is shunted for the time of arc quenching by additional three-phase switch of 35 kV, phases of which are connected parallel to every phase of reactor control winding. Versions of specified invention are the cases, when in cycle of "ОАПВ" with the help of corresponding phase of 35 kV switch only one phase of the secondary control winding delta is shunted, which corresponds to the phase of line, in which single-phase earth fault occurred, or when switch is not available, compensation of capacitance current of arc is carried out with limit saturation of "healthy" phases of reactor by command of automatic control systems.
EFFECT: higher accuracy.
3 cl,1 dwg
FIELD: switches controlled by zero-sequence currents.
SUBSTANCE: proposed device has operating mechanism 10 for automatic reclosure of zero-sequence current controlled switch 2 connected to supply mains 8, 9 in front of load, control facility 1 designed to actuate operating mechanism 10 and connected in front of zero-sequence current controlled switch, as well as past the latter and in front of load for bypassing mentioned zero-sequence current controlled switch during its disconnection; control facility has circuit 20 that functions to check device for connection to power line and circuit 23, for detecting leakage currents, both used to check for leakage currents before actuating operating mechanism for reclosing zero-sequence current controlled switch; control facility is connected to power line through switch designed for ON-operation upon disconnection of zero-sequence current controlled switch.
EFFECT: enhanced reliability.
8 cl, 3 dwg
FIELD: electrical engineering; controlling feeder switches of alternating-current traction substations.
SUBSTANCE: proposed method for controlling switching apparatuses such as feeder switches of 27.5 and 2 x 27.5 kV AC traction substations includes primary determination of cause of expected disconnection of switch by means of digital terminals as early as before switch disconnection, that is, it is found out if switch disconnection will occur as result of malfunction of terminal protective gear due to processes in traction load current or short circuit; to this end percentage of third harmonic in current through switch or shift angle between first harmonics of current through switch and voltage across 27.5-kV traction substation buses are evaluated during period between sending OFF- and ON-operation commands to switch; terminal sends commands for connection or disconnection of switch in compliance with processes occurring in traction load current and residual voltage; in addition, point of short circuit in disconnected section of traction line is located by means of proposed device.
EFFECT: enhanced safety in operation.
2 cl, 1 dwg
FIELD: automating power supplies of railway automatic and teleautomatic equipment including feeder turn-on devices.
SUBSTANCE: proposed device has three comparators 3-5 connected to feeder phase leads, AND circuit 7 integrating signals of comparators 3-5, OR circuit 2 connected to load phase leads, inverter 6 connected to output of OR circuit 2, inverter connected to output of AND circuit 7 and to reset input of flip-flop 12, AND circuit 8 one of whose inputs is connected to output of AND circuit 7, other input, to output of inverter 6, and output, to setting input flip-flop 12. Newly introduced in device are shaper of limited number of closing and reclosing signals for relay and starter, start-of-operation delay component 9 for shaper 13 designed to afford device operation without attempting relay reclosure in response to feeder first normalized phase voltages, inverter 11 whose input is connected to output of component 9 and output, to input of shaper 13, inverter 14 whose input is connected to output of shaper 13, AND circuit 15 one of whose inputs is connected to output of inverter 14, other input, to output of flip-flop 12, and output, to external relays unit.
EFFECT: enhanced reliability.
1 cl, 1 dwg
FIELD: automation of power systems; overload protection of power supplies.
SUBSTANCE: proposed device designed for recovering load power circuit by its automatic reclosure including automatic elimination of overcurrent causes has resistor, first and second measuring transducers, switch, input and output leads, common lead, and newly introduced first and second comparators, first and second reference-level setting elements, and RS flip-flop.
EFFECT: enlarged functional capabilities.
1 cl, 1 dwg
FIELD: electrical engineering; electronic relays responding to increment in current, for instance reverse-sequence current.
SUBSTANCE: proposed relay has intervening current transformer whose input functions as information input of current relay; rectifier; final element; first, second, and third threshold units; first and second AND gates; reversing counter; monostable multivibrator; clock generator; and frequency sensor; monostable multivibrator input functions as trigger input of current relay; newly introduced in device are algebraic adder whose output is connected to first threshold unit input; delay unit whose input is connected to addition input of algebraic adder and to rectifier output and output, to algebraic adder subtraction input; short-pulse shaper; and third AND gate whose direct input is connected to second short-pulse shaper and to HIGHER output of first threshold unit, inverse input, to short-pulse shaper output; output of third AND gate is connected to second direct input of second AND gate.
EFFECT: enhanced noise immunity.
1 cl, 4 dwg
FIELD: electrical engineering; electronic current relays.
SUBSTANCE: proposed current relay has intervening current transformer, rectifier, two final components, three threshold units, two AND gates, reversing counter, monostable multivibrator, clock generator, frequency divider, adder, subtraction unit, clipper limiter, and two low-pass filters.
EFFECT: enlarged functional capabilities.
1 cl, 2 dwg