Device for remote protection of overhead power lines
The device addresses the complexity and reliability issues of existing relay protection by employing induction coils and reed switches for remote protection of overhead power lines, simplifying design and enhancing reliability through voltage comparison and adjustable coil positioning.
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Patents
- Current Assignee / Owner
- FEDERALNOE GOSUDARSTVENNOE BJUDZHETNOE OBRAZOVATELNOE UCHREZHDENIE VYSSHEGO OBRAZOVANIJA NATSIONALNYJ ISSLEDOVATELSKIJ UNIV MEHI FGBOU VO NIU MEHI
- Filing Date
- 2025-07-17
- Publication Date
- 2026-06-30
Smart Images
Figure 00000001_ABST
Abstract
Description
[0001] Field of technology to which the invention relates
[0002] The invention relates to electrical engineering, namely to relay protection, and can be used for remote protection of overhead power lines with voltage equal to or higher than 110 kV.
[0003] Technology Level
[0004] A device for maximum current protection of an electrical installation is known (RU patent No. 2705213, published on 06.11.2019, IPC H02H 3 / 28, H02H 7 / 08), containing a current sensor, which is a measuring transducer placed in an electrically insulating housing in the form of a flat inductance coil and a cable amplifier connected to it, a responding element in the form of a diode bridge, to one diagonal of which a cable amplifier is connected through an electric capacitor, and to the other diagonal - a relay with an adjustable response threshold.
[0005] The disadvantage of this technical solution is the placement of the current sensor in close proximity to the current-carrying parts of the protected electrical installation, with its placement in an electrically insulating porcelain housing at the closest possible distance from the current-carrying busbar, which, when replacing a failed current sensor and cable amplifier, requires dismantling the electrically insulating housing.
[0006] The closest in technical essence to the proposed invention is a differential protection device on reed switches and a magnetoresistor for a converter installation with a transformer and a rectifier (patent RU No. 2614243, published 03 / 24 / 2017, IPC H02H 7 / 10), containing a reed switch, an actuator, the output of which is connected to the trip circuit of a switch of an electrical installation, first, second and third reed switches with control windings, first and second adjustable resistors, to the first output of which the ends of the control windings of the first, second and third reed switches are connected.
[0007] The disadvantages of this technical solution are the use of a significant number of elements and low reliability of protection of overhead power lines with a voltage of 110 kV and above, which can lead to failure of the protection to operate.
[0008] Disclosure of the essence of the invention
[0009] The technical objective of the proposed invention is to implement remote protection of overhead power lines using induction coils, based on the principle of voltage comparison.
[0010] The technical result consists in simplifying the design of the device and increasing the reliability of protection of overhead power lines.
[0011] This is achieved by the fact that the known device for remote protection of overhead power lines, containing the first, second and third reed switches with a closing contact, an intermediate relay with a winding, six adjustable resistors (R 1,2,3 and R 4,5,6) and an indicator relay with a winding, equipped with a bar on which the first, second and third reed switches are secured with the help of first clamps, a first supporting post, on the first end of which the bar is installed with the help of the first screw, and the second end of which is secured to the wall of the operational control cabinet with the help of the second screw, wherein the reed switches are placed inside the control windings, connected in opposite directions, and the bar with the reed switches is installed in the operational control cabinet, an automatic switch, six inductance coils (KI 1-6 ), the second clamps, the first and second bolt-nut connections, the second support post, the third clamps, the first and second groups of voltage amplifiers (U 1-3 and U 4-6), connecting cable, voltage amplifier unit, relay unit, wherein the first contact cores of the closing contact of the reed switches are connected to the plus pole of the circuit breaker, and the first terminal of the intermediate relay winding is connected to the second contact core of the closing contact of the reed switches, the second terminal of the intermediate relay windings is connected to the minus pole of the circuit breaker, six inductance coils (CI 1-6 ) by means of second clamps and with the help of the first bolt-nut connection are attached to the second supporting post, which, in turn, by means of third clamps is attached with the help of the second bolt-nut connection to the current-carrying buses, six voltage amplifiers (U) are connected to the terminals of the inductor coils 1-6 ), so that the terminals of the first and second groups of inductance coils (CI) 1-3 and KI 4-6 ) are connected to the first terminals of the first and second groups of voltage amplifiers (U 1-3 and U4-6 ) connecting cable to the first and second groups of voltage amplifiers (U 1-3 and U 4-6 ) the input of six adjustable resistors (R) is connected 1,2,3 and R 4,5,6 ), the output of which is connected to the control winding of the reed switches, to the contact for closing the intermediate relay connected to the plus pole of the circuit breaker, by means of an indicator relay with a winding, the drive of the circuit breaker is connected, its second output is connected to the minus pole of the circuit breaker, six voltage amplifiers (U 1-6 ) and adjustable resistors (R 1-6 ) are located in the voltage amplifier block, and the intermediate and indicator relays are located in the relay block, the voltage amplifier block and the relay block are placed in the operational control cabinet, and the inductance coils (KI 1-6) with the help of a second support post are located on the current-carrying buses of block-modular closed switchgears (ZRU) with a voltage of 110 kV, which are connected on both sides to an overhead power line.
[0012] Brief description of drawings
[0013] The essence of the invention is explained by the drawings, where Fig. 1 shows a bar with reed switches and its: a) front view; b) rear view; Fig. 2 shows the operational control cabinet; Fig. 3 shows the structural diagram of the device for remote protection of overhead power lines; Fig. 4 shows the induction coil with elements for its fastening; Fig. 5 shows the arrangement of the induction coils in the block-modular indoor switchgear of 110 kV; Fig. 6 shows a general view of the connection of the protected overhead power line to the block-modular indoor switchgear of 110 kV.
[0014] Implementation of the invention
[0015] The device for remote protection of overhead power lines comprises first, second and third reed switches 1 with a closing contact 2, which are secured by first clamps 3 to a bar 4 installed on the first end of the first supporting post 5 using a first screw 6 (Fig. 1). The second end of the first supporting post 5 is secured to the wall of the operational control cabinet 7 using a second screw 8 (Fig. 1b). The reed switches 1 are located inside the control windings 9, connected in opposite directions. The bar 4 with the reed switches 1 is installed in the operational control cabinet 7 (Fig. 2).
[0016] The first contact cores 10 of the closing contact 2 of the reed switches 1 are connected to the plus pole of the circuit breaker 11, and the first terminal of the winding 13 of the intermediate relay 14 is connected to the second contact core 12 of the closing contact 2 of the reed switches 1. The second terminal of the windings 13 of these relays 14 is connected to the minus pole of the circuit breaker 11 (Fig. 3). Six inductance coils (CI) 1-6) 15, by means of second clamps 16 and with the help of the first bolt-and-nut connection 17 are attached to the second supporting post 18 (Fig. 4). The second supporting post 18 is attached by means of third clamps 19 with the help of the second bolt-and-nut connection 20 to the current-carrying buses 21 (Fig. 5).
[0017] Six voltage amplifiers (U1-6) 22 are connected to the terminals of the inductance coils 15, so that the terminals of the first and second groups of inductance coils (KI 1-3 and KI 4-6 ) 15 are connected to the first terminals of the first and second groups of voltage amplifiers (U 1-3 and U 4-6 ) 22 connecting cable 23.
[0018] To the first and second groups of voltage amplifiers (U 1-3 and U 4-6 ) 22 connected to the input of six adjustable resistors (R 1,2,3 and R 4,5,6 ) 24, the output of which is connected to the control winding of 9 reed switches 1.
[0019] The drive 28 of the circuit breaker is connected to the closing contact 25 of the intermediate relay 14, connected to the “plus” pole of the circuit breaker 11, via the indicator relay 26 with the winding 27, its second output is connected to the “minus” pole of the circuit breaker 11.
[0020] Six Voltage Amplifiers (U 1-6 ) 22 and adjustable resistors (R 1-6 ) 24 are located in the voltage amplifier block 29, and the intermediate 14 and indicator 26 relays are located in the relay block 30. The voltage amplifier block 29 and the relay block 30 are located in the operational control cabinet 7.
[0021] Inductance coils (KI 1-6 ) 15 with the help of the second supporting rack 18 are located on the current-carrying buses 21 of the block-modular closed switchgear (ZRU) with a voltage of 110 kV, which are connected on both sides to the overhead power line 31.
[0022] All structural elements of the proposed device are made of lightweight and durable plastic, such as "PLA", printed on a 3D printer, except for: the first 6 and second 8 screws; the first 17 and second bolt-nut 20 connections, made of a non-magnetic material, as well as reed switches 1, inductor coils 15, intermediate 14 and indicator relay 26.
[0023] The reed switches 1 can be of the KEM-1 type, their control windings 9 can be implemented using the windings of the intermediate relay of the RP 16 type; the circuit breaker 11 is the AP-50 type switch; the inductance coils 15 are the windings of the intermediate relay of the RP 23 type; the connecting cable 23 is the Olflex classic 100 4 1.5 cable; the adjustable resistors 24 are the SP-3 resistors; the intermediate relay 14 is the RT570220 type relay; the indicator relay 26 is the RU-21 type relay.
[0024] The overhead power line remote protection device operates as follows.
[0025] On each current-carrying busbar 21, observing the minimum permissible distance according to the Electrical Installation Code, equal to 700 mm from it, the second supporting post 18 is fixed together with the first and second groups of induction coils (ICs) 1-3 and KI 4-6 ) 15 (Fig. 4), while at the beginning of the induction coil KI 15 are installed inside the detachable second clamps 16 and, using the first bolt-and-nut connection 17, are secured to the second supporting post 18. The second supporting post 18 itself, using the third clamps 19, using the second bolt-and-nut connection 20, is secured to the current-carrying buses 21 (Fig. 5). Before installing and securing the induction coils KI 15 in the block-modular switchgear of 110 kV, they are installed taking into account the maximum parameters of the magnetic field induced by each current-carrying busbar 21 (in those places where the current-carrying busbars have the maximum value of magnetic induction) and the convenience of placing the KI 15, while the KI 15 are located perpendicular to the plane of the cross-section of the current-carrying busbars 21. The circuit breaker 11 is turned on and the “plus” potential is applied to the first contact cores 10 of the reed switch 1 (Fig. 3).
[0026] The operating principle of the proposed device is based on comparing the voltage values at the beginning and end of the protected overhead power line 31, similar to comparing its resistance value - as in traditional distance protection (Fig. 6). The protected zone of this device is the overhead line 31 between two groups of inductance coils (ICs) 1-3 ) and (KI 4-6 ) 15, installed on both sides (on the current-carrying buses 21) and having the same parameters. The effect of magnetic fluxes F, created by currents in the phases of the overhead line 31 on the inductance coils KI 15 is shown by arrows (Fig. 3). Voltage amplifiers (U 1-6) 22 increase the voltage value taken from the terminals of the inductance coils KI 15 to the required value. If necessary, it is possible to move the inductance coils KI 15 towards or away from the current-carrying busbar 21 by means of the second supporting post 18, thereby allowing for additional adjustment of the tripping settings of the distance protection (Fig. 4, 5).
[0027] In normal operation of the electrical installation, the parameters in the device are adjusted using adjustable resistors (R 1-6 ) 24 so that the voltages U1 and U2 coincide in magnitude, as a result of which the device circuit does not react to external short circuits (outside the protected overhead power line 31) (Fig. 3).
[0028] When a short circuit occurs on the protected overhead power line 31, the current in the current-carrying buses 21 increases, and the inductance coil KI 15 reacts to changes in the magnetic field around this bus 21, and an increased EMF value is induced in KI 15 (Fig. 5). Due to the fact that this voltage value, taken from the terminals of the inductance coil 15, is small (about 20-25 V), it is increased using a voltage amplifier (U 1-6) 22 to a voltage value equal to U=220 V and is supplied to the first terminal of the control winding 9 of the reed switch 1 (Fig. 1). In this case, the voltages U1 and U2 are directed in different directions and are not equal to each other - they differ, and in connection with this, the currents in the control windings 9 of the reed switches 1, creating a magnetic flux acting on these reed switches 1 (Fig. 1, 3), will also differ. As a result of achieving this difference between the voltages U1 and U2 - a value sufficient for the operation of the reed switch 1, it, under the influence of the magnetic field created by the control winding 9, operates and closes between itself the first 10 and second 12 of its contact cores and sends a signal "+", coming from the automatic switch 11, to the first terminal of the winding 13 of the intermediate relay 14 (Fig. 3). This relay 14, having been triggered, sends a signal to turn off the drive 28 of the switch through the first terminal of the winding of the indicator relay 26, which is connected to its contact 25 for closing.As a result, the protected overhead power line 31 is disconnected (Fig. 6).
[0029] Thus, the proposed invention implements remote protection of overhead power lines, performed on the principle of voltage comparison, using two groups of inductance coils (IC) 1-3 ) and (KI 4-6 ), installed on both sides of an overhead power line in a modular indoor switchgear (ZRU) (on BM ZRU-110 kV busbars) with a voltage of 110 kV or higher. The proposed device compares voltage values at the beginning and end of the protected overhead power line, similar to comparing its resistance—as in traditional distance protection.
[0030] Also, with the help of the second support post, the possibility of moving the induction coils to or from the busbar is realized, thereby allowing for additional adjustment of the distance protection response settings.
[0031] The proposed invention, compared to the prior art, reduces the number of design elements (which reduce the operational reliability of the entire device): the converter unit and transformer are eliminated, and the number of reed switches is significantly reduced, increasing the reliability of overhead power line protection. The operating algorithm has been fundamentally modified through the use of a new method for adjusting the response settings (in the prior art, this is accomplished by varying the adjustable resistances in the reed switch coil supply circuit; in the proposed invention, this is accomplished by changing the coil position relative to the conductors). The device's overall dimensions have also been reduced, simplifying its installation in distribution boards.
[0032] The use of the invention makes it possible to simplify the design of the device and increase the reliability of the protection of overhead power lines.
Claims
A device for remote protection of overhead power lines, comprising first, second and third reed switches with a closing contact, an intermediate relay with a winding, six adjustable resistors (R 1,2,3 and R 4,5,6 ) and an indicator relay with a winding, characterized in that it is equipped with a bar on which the first, second and third reed switches are secured with the help of first clamps, a first supporting post, on the first end of which the bar is installed with the help of the first screw, and the second end of which is secured to the wall of the operational control cabinet with the help of the second screw, wherein the reed switches are placed inside the control windings, connected in opposite directions, and the bar with the reed switches is installed in the operational control cabinet, an automatic switch, six inductance coils (KI 1-6 ), the second clamps, the first and second bolt-nut connections, the second support post, the third clamps, the first and second groups of voltage amplifiers (U 1-3 and U 4-6), connecting cable, voltage amplifier unit, relay unit, wherein the first contact cores of the closing contact of the reed switches are connected to the plus pole of the circuit breaker, and the first terminal of the intermediate relay winding is connected to the second contact core of the closing contact of the reed switches, the second terminal of the intermediate relay windings is connected to the minus pole of the circuit breaker, six inductance coils (CI 1-6 ) by means of second clamps and with the help of the first bolt-and-nut connection are attached to the second supporting post, which, in turn, by means of third clamps is attached with the help of the second bolt-and-nut connection to the current-carrying buses, six voltage amplifiers (U) are connected to the terminals of the inductor coils 1-6 ), so that the terminals of the first and second groups of inductance coils (IC) 1-3 and KI 4-6 ) are connected to the first terminals of the first and second groups of voltage amplifiers (U 1-3 and U 4-6) connecting cable to the first and second groups of voltage amplifiers (U 1-3 and U 4-6 ) the input of six adjustable resistors (R) is connected 1,2,3 and R 4,5,6 ), the output of which is connected to the control winding of the reed switches, to the contact for closing the intermediate relay connected to the plus pole of the circuit breaker, by means of an indicator relay with a winding, the drive of the circuit breaker is connected, its second output is connected to the minus pole of the circuit breaker, six voltage amplifiers (U 1-6 ) and adjustable resistors (R 1-6 ) are located in the voltage amplifier block, and the intermediate and indicator relays are located in the relay block, the voltage amplifier block and the relay block are placed in the operational control cabinet, and the inductance coils (KI 1-6) with the help of a second support post are located on the current-carrying buses of block-modular closed switchgears (ZRU) with a voltage of 110 kV, which are connected on both sides to an overhead power line.