Buffer for decision making on disconnection in adaptive detection of short circuit through arc

FIELD: electricity.

SUBSTANCE: device for detection and filtration of undesired events of disconnection of short circuit through an arc contains: a storage to store data of one or more types of events of disconnection of short circuit through an arc, previously detected in a circuit within a certain period of time, with each previously detected type of event of disconnection of short circuit through an arc leading to the interruption of the circuit at least once, if detected; and a processor, which communicates with the storage, while the processor is adapted to determine whether the newly detected event of disconnection of short circuit through an arc is an undesired event of disconnection, based on the number of times of one and the same type of the event of disconnection of short circuit through an arc, which occurred earlier, as a newly detected event of disconnection of short circuit through an arc, and to forbid the interruption of the circuit if the newly detected event of disconnection of short circuit through an arc is determined as an undesired event of disconnection.

EFFECT: providing filtration of undesired events of disconnection of short circuit through an arc.

19 cl, 5 dwg

 



 

Same patents:

FIELD: electricity.

SUBSTANCE: device with earthed neutral protecting capacitor bank against internal faults comprises a microprocessor processing digital values of unbalance current, current measured at input to the capacitor bank, voltage measured at busbars of the substation. The microprocessor perform calculation of valid values for orthogonal components of phase current and voltage, calculation of compensating current and zero-sequence current. Comparing current values with consideration of the preset braking value the microprocessor forms the sign of protection actuation. Switching the sign of protection actuation on and off is made with consideration of the preset resetting coefficient. According to a separate algorithm the microprocessor also forms sign of failure for secondary control voltage circuits and blocks the sign of protection actuation when the sign of failure for secondary control voltage circuits is positive. The microprocessor identifies the modes when burning of sectional fuses is possible; it calculates relative value of imbalance current, increment of the relative imbalance current, and total imbalance current as per diagonal lines with capacitors. Comparing value of the total imbalance current with setting the microprocessor generates a signal specifying available capacitors with burnt sections.

EFFECT: providing protection for a bank of capacitors.

5 dwg, 2 tbl

FIELD: electricity.

SUBSTANCE: invention is used in the field of electric engineering and power engineering. The device contains three windings, each is placed in a separate rod from magnetic material, "star" or "zigzag" connected the inputs each of which is connected to the respective phase conductor of the electric network, and the neutral point is connected to the input of the fourth winding with alternating inductance placed on the fourth rod from magnetic material with air gaps. The output of the fourth winding is connected to the earth, all four rods are connected by yokes from one and from another side. Yokes, connecting the rods of the first three windings are joined as two symmetric three-beam stars at an angle 120 degrees with reference to each other, and the fourth rod connects joining places of yokes. Parallel to the fourth coil the variable active and reactive resistance (inductive or capacitive) is connected. The fourth coil is designed with branches, and variable active and reactive resistance through the switching device is connected parallel to a part of turns of the fourth coil. On the fourth rod the additional fifth coil is placed and to leads of this coil in parallel with it the second variable active and reactive resistance is connected.

EFFECT: improvement of accuracy of compensation of capacitor currents of single-phase short circuits to earth and expansion of range of change of the device parameters.

4 cl, 5 dwg

FIELD: electricity.

SUBSTANCE: invention relates to the field of electrical equipment and can be used for AC/DC conversion. The reversible valve inverter contains two opposite directed DC sources combined by common terminals intended for connection to a load, is fitted with the protection tripping device (PTD), the first contact terminal in the position of the first pass is connected to the second terminal of the first source, and the first contact terminal in the position of the second pass of PTD is intended for connection to the second terminal of the load, and coil terminals of PTD are combined, and the middle point of PTD formed by connection of the contact and the winding is connected to the second terminal of the load.

EFFECT: reliability improvement.

1 dwg

FIELD: electrical engineering.

SUBSTANCE: device incorporates extra second four-phase bridge rectifier with output terminals making the device output terminals and three differentiating inductive current inverters. Current second windings starts are connected to common zero terminals of the machine. Ends of said windings are connected with appropriate ends of the machine phase windings. Starts of the latter are connected to ends of appropriate third current windings. Starts of the latter are connected to ends of conductors phased with the line for connection of the machine to its switch. Input terminals of second rectifier are connected to common zero terminal of the device and to starts of third coils of all groups. Ends of the latter are connected to said connectors and the device appropriate phase.

EFFECT: reliable fault protection.

1 dwg

FIELD: electrical engineering.

SUBSTANCE: proposed device comprises electrically connected circuit voltage rectifier, voltage divider, ADC, microprocessor, digital electronic commutator, indication unit and commutation unit. Circuit voltage rectifier is composed by full-wave voltage rectifier. Said ADC is composed by ADC built in microprocessor.

EFFECT: higher noise immunity to circuit pulse interferences and flexibility.

1 dwg

FIELD: electricity.

SUBSTANCE: power supply circuit coupled to the network line with positive potential and GND-potential of the supply unit comprises a coil connected by its first output to positive potential and by its second output to GND-potential, a semiconductor switch switched on between the coil and GND-potential, a semiconductor switch switched on between positive potential and coil, a diode connected between the second output of the coil and positive potential if straight direction and a diode switched on between GND-potential and the first output of the coil in straight direction. An accumulator battery charged from the network supply unit in the process phase may be charged by energy accumulated in the coil from one of process phases with further supply by recuperated energy of the coil. The microcontroller activates semiconductor switches depending on parameters of a signal tracked by the detection circuit; when current reaches threshold value at the coil the microcontroller switches the semiconductor switches off so that current starts passing through the recuperating circuit and when current decreases up to minimum value the microcontroller switches the semiconductor switches on so that the coil starts using the recuperated energy.

EFFECT: reducing power consumption.

3 cl, 3 dwg

FIELD: electricity.

SUBSTANCE: currents are measured in each phase from the side of an electric motor cutout terminals and zero terminals, the current values are compared between each two phases both from the side of the electric motor cutout terminals and the zero terminals, and when from the side of the cutout terminals for one phase the current value is less than current value for the other two phases in the modulus by n times, where n>1, and from the side of the zero terminals the current value in the same phase is more than the current values for the other two phases by m times, where m>1, then the signal is sent to switch off the motor cutout.

EFFECT: increased sensitivity to currents of the double-phase short circuit.

3 dwg

FIELD: electricity.

SUBSTANCE: use: in the field of electric engineering. The device comprises input and output buses and switching elements, which are made in the form of a group of primary ones, according to the number of energy generation channels, providing for their connection to a power supply bus in accordance with the specified conditions, and in the form of a group of secondary ones, in accordance with the number of loads, providing for their connection to the power supply bus in accordance with information on the procedure of connection, realised in the introduced control device, which is connected with the help of a multiplex information bus to all switching elements, at the same time the switching element based on a semiconductor electronic key comprises sensors of current and voltage, sensors of environmental parameters, connected to a microcontroller, interacting via an information multiplex bus with a control device, which makes it possible to perform diagnostics and switching of energy generation and consumption channels in accordance with information on reference values of currents, voltages and parameters (for instance, temperature of the electronic key) of environment stored in the memory of the microcontroller.

EFFECT: expansion of functional capabilities.

2 dwg

FIELD: electricity.

SUBSTANCE: invention is attributed to the field of electric engineering and can be used for protection of power supply grids. For protection of parallel lines of the power supply grid the first protective instrument (13a) is connected to the first line (11a) of the power supply grid for registration of measured values, which characterise working condition of the first line (11a). The first protective instrument (13a) via a communication connection (15) is connected to the second protective instrument (13b) located nearby. In order to increase reliability and selectivity during monitoring of parallel lines, a method is proposed, in which the second protective instrument (13b) is connected to the second line (11b) of the power supply grid stretching in parallel to the first line (11a). Both protective instruments (13a, 13b) exchange measured data recorded by them relative to their appropriate line (11a, 11b), and/or signals produced from these measured values. Each protective instrument (13a, 13b) is made as capable of performing a protective function for its appropriate line (11a, 11b) when performing the main logic (25) of protections. Each protective instrument for performance of its main logic (25) of protection involves measured values registered on its own line (11a), and also measured values and/or signals accepted from another protective instrument (13b).

EFFECT: increased reliability and selectivity of decisions on working conditions of parallel lines of a multi-phase power supply grid.

23 cl, 11 dwg

FIELD: electricity.

SUBSTANCE: device contains a directional element consisting of matching current and voltage converters of transformer type, two frequency filters, two emergency component filters, two current and voltage signs comparator circuits, two univibrators, two inhibit circuits and a starting element consisting of a commercial frequency filter, an inhibit circuit, a voltage relay, AND element, a time element and two output relays, there are also auxiliary inhibit circuit, a commercial frequency filter, two threshold elements, two time elements and two output relays.

EFFECT: improving operational reliability of the device at failure of zero-sequence voltage circuits or at non-availability of voltage at the distribution point or at the transformer substation with which zero-sequence voltage circuits can be arranged.

1 dwg

FIELD: electricity.

SUBSTANCE: invention relates, without limitation, to the method to generate a fault signal (F), which indicates a fault in a plant (11) of energy transmission (an element of a transmission system), besides, within the method it is inspected, where a start-up process takes place in the energy transmission plant, and fault signal generation is blocked, if the start-up process takes place. In accordance with the invention it is provided that an inspection is carried out to confirm whether at least one current (I1, I2, I3, I4) of the energy transmission plant within the specified minimum time interval for duration of the current period has a flat current characteristic, and the fault signal generation is blocked, if at least one current within the specified minimum time interval has a flat current characteristic.

EFFECT: elimination of false signal generation.

24 cl, 5 dwg

FIELD: electricity.

SUBSTANCE: present invention can be used in electrical engineering for protection false triggering of fire extinguishing systems. The device has three protection stages. The first is in form of an aerial fuse with three electrodes, one of which is earthed. The second stage has induction coils and series-connected semiconductor voltage limiters, in form of TVS - bidirectional diodes or varistors or protective thyristors, the common point of which is connected to the earthed electrode of the aerial fuse. The other two electrodes are connected to the induction coils. The third protection stage has a series circuit of a diode and coils of an electromagnetic relay, and is connected to the triggering wires in parallel to the semiconductor voltage limiters. The relay contacts shunted with a resistor can be fitted in any of the triggering wires. When there is fire, trigger voltage and current are applied in opposite direction to the control voltage and current, closing the relay contacts, thus triggering the pyrocartridge.

EFFECT: equalisation of potential between triggering wires and any of the triggering wires and earth, and reduced number of elements of the circuit.

7 cl, 5 dwg

The invention relates to power engineering and can be used as the protection of special interest for military and civilian purposes such as command posts, missile facilities, stations and switchgear to power most responsible consumers

The invention relates to the field of electrical engineering, in particular to relay protection and is intended for use in the composition of the relay protection devices in which the input of the influencing quantities are voltage, including the zero-sequence voltage, or as a separate device that controls the functioning of secondary circuits of voltage transformers connected in a star schema broken Delta

FIELD: electricity.

SUBSTANCE: present invention can be used in electrical engineering for protection false triggering of fire extinguishing systems. The device has three protection stages. The first is in form of an aerial fuse with three electrodes, one of which is earthed. The second stage has induction coils and series-connected semiconductor voltage limiters, in form of TVS - bidirectional diodes or varistors or protective thyristors, the common point of which is connected to the earthed electrode of the aerial fuse. The other two electrodes are connected to the induction coils. The third protection stage has a series circuit of a diode and coils of an electromagnetic relay, and is connected to the triggering wires in parallel to the semiconductor voltage limiters. The relay contacts shunted with a resistor can be fitted in any of the triggering wires. When there is fire, trigger voltage and current are applied in opposite direction to the control voltage and current, closing the relay contacts, thus triggering the pyrocartridge.

EFFECT: equalisation of potential between triggering wires and any of the triggering wires and earth, and reduced number of elements of the circuit.

7 cl, 5 dwg

FIELD: electricity.

SUBSTANCE: invention relates, without limitation, to the method to generate a fault signal (F), which indicates a fault in a plant (11) of energy transmission (an element of a transmission system), besides, within the method it is inspected, where a start-up process takes place in the energy transmission plant, and fault signal generation is blocked, if the start-up process takes place. In accordance with the invention it is provided that an inspection is carried out to confirm whether at least one current (I1, I2, I3, I4) of the energy transmission plant within the specified minimum time interval for duration of the current period has a flat current characteristic, and the fault signal generation is blocked, if at least one current within the specified minimum time interval has a flat current characteristic.

EFFECT: elimination of false signal generation.

24 cl, 5 dwg

FIELD: electricity.

SUBSTANCE: device for detection and filtration of undesired events of disconnection of short circuit through an arc contains: a storage to store data of one or more types of events of disconnection of short circuit through an arc, previously detected in a circuit within a certain period of time, with each previously detected type of event of disconnection of short circuit through an arc leading to the interruption of the circuit at least once, if detected; and a processor, which communicates with the storage, while the processor is adapted to determine whether the newly detected event of disconnection of short circuit through an arc is an undesired event of disconnection, based on the number of times of one and the same type of the event of disconnection of short circuit through an arc, which occurred earlier, as a newly detected event of disconnection of short circuit through an arc, and to forbid the interruption of the circuit if the newly detected event of disconnection of short circuit through an arc is determined as an undesired event of disconnection.

EFFECT: providing filtration of undesired events of disconnection of short circuit through an arc.

19 cl, 5 dwg

FIELD: automatic load regulation and protection in dc and ac circuits.

SUBSTANCE: proposed method implies output voltage control by varying active resistance of component being regulated. Output voltage is compared with permissible maximal and minimal values. Comparison results are submitted in the form of low and high levels of respective signals and processed so that if output voltage is within permissible limits, control signal is not generated nor supplied to component being regulated. If output supply voltage rises beyond maximum permissible value for short time, control signal is generated and supplied to component being regulated for stabilizing it. If output voltage exceeds maximum permissible value or drops below its permissible minimum, protective gear disconnects load from supply mains upon expiration of preset time interval.

EFFECT: ability of regulating both ac and dc voltages; reduced time of load running at output voltage beyond its permissible values.

1 cl, 3 dwg

FIELD: protection of a three-phase power equipment against asymmetry of currents, current ground leakage and affection of man by electric current.

SUBSTANCE: the method of protection consists in estimation of instantaneous values of asymmetry of phase currents in the load, comparison of these values with the tolerance and disconnection of the load from the source of the three-phase power mains in case the value of asymmetry of currents in the load is out of the tolerance. The device has a magnetic starter and a load, in addition it has a relay for estimation of the degree of asymmetry of phase currents in the load, whose inputs are in-phase connected to the outputs of the magnetic starter, and the outputs - to the load inputs, and the relay break contacts are series-connected to the magnetic starter winding.

EFFECT: enhanced reliability and equipment duplication.

1 cl, 3 dwg

FIELD: switching of DC power networks.

SUBSTANCE: the controller consists of buffer (1), galvanic decoupling assembly (2) control and protection assembly (3), voltage conversion assembly (4), switch (5) and time-delay assembly (6).

EFFECT: provided in-line monitoring of the present condition of load current, reduced power consumption, expanded field of application, simplified controller construction and, as a result, reduced cost.

1 dwg

FIELD: insulated-neutral alternating-current low-voltage power distribution networks and two-wire direct-current networks.

SUBSTANCE: proposed method includes current (voltage) and insulation resistance measurements, comparison of measured values with relay settings tuned away from normal transient conditions of equipment under protection, and operation of final element in case measured values exceed setting ones; relay operating current (voltage) settings are tuned away from continuous admissible conditions provided ground-fault or current (voltage) relays operate simultaneously or sequentially one after another but within selective time delay of protective gear. Two design alternated of device implementing this method are also proposed.

EFFECT: enhanced response to arcing short circuits.

4 cl, 2 dwg

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