Overhead ground wire ice-melting transformer and ice-melting system used in power grid non-stop state

Abstract

The invention relates to an overhead ground wire ice melting transformer for a power grid in a non-stop state, and belongs to the technical field of overhead ground wire ice melting. The overhead ground wire ice melting transformer comprises a transformer body, primary windings of the transformer body are connected with a three-phase alternating current power supply, and two pairs of primary windings and secondary windings are arranged in pairs; in the primary windings, two ends of a first primary winding are used for being connected with an A phase and a B phase of a power system, one end of a second primary winding is electrically connected with a midpoint of the first primary winding, and the other end of the second primary winding is connected with a C phase; in the secondary winding, the first secondary winding is used for being connected in series with a first power supply loop; the second secondary winding is connected in series with a second power supply loop; and the first power supply loop and the second power supply loop are mutually independent and are respectively connected in series with a load adjusting module for changing the loop load. The invention further relates to an overhead ground wire ice melting system for the power grid in the non-stop state. The overhead ground wire ice melting system comprises a ground wire tail end connection controller and the overhead ground wire ice melting transformer.

Description

Technical Field

[0001] The invention belongs to the technical field of overhead ground wire de-icing, and relates to an overhead ground wire de-icing transformer and an de-icing system for a power grid in a non-stop operation state. Background Art

[0002] Power system failures due to ice covering overhead transmission lines and overhead ground wires occur frequently in winter, easily causing large-scale power outages in cities and rural areas. In view of this, it is necessary to melt the ice on overhead transmission lines and overhead ground wires to eliminate failures and safety hazards.

[0003] Currently, DC ice melting is often used in existing technologies, but the DC ice melting method still has the following shortcomings:

[0004] Ground wire de-icing is time-consuming and inefficient. DC ground wire de-icing requires segmented de-icing, and the time required to de-icing overhead ground wires far exceeds that required to de-icing conductors (according to statistics, ground wire de-icing accounts for approximately 70% of the total de-icing operations). This occupies a large amount of de-icing resources and significantly reduces the de-icing efficiency of DC de-icing devices. Furthermore, due to the varying types and resistances of transmission line ground wires, DC de-icing requires segmented de-icing, which is time-consuming. Furthermore, in order to match the resistance of each ground wire segment, it is not possible to guarantee that the ground wires within the same de-icing segment are of the same type, resulting in unsatisfactory de-icing effects in individual sections.

[0005] Transmission lines must be shut down, impacting power supply reliability. Using DC de-icing requires shutting down transmission lines. If the lines are not shut down, accidental contact between the de-icing device and live lines could cause short circuits or even equipment explosions. Applying DC current to a live line can cause an abnormal increase in the grounding potential, risking insulator breakdown due to overvoltage, and abnormal current distribution in the grounding system, impacting the logic of relay protection devices. If the transmission line is operating (AC voltage), the addition of DC de-icing current can generate harmonics or electromagnetic interference, threatening the safety of line equipment (such as transformers and capacitors). When a transmission line is operating, the conductors are energized with three-phase AC, making it difficult to directly form a controllable DC circuit with the ground wire / OPGW. Forcing a circuit can lead to uncontrolled current due to phase differences. Relay protection devices can misinterpret the DC current as a fault current (such as a ground fault), causing false tripping of the line and expanding the scope of the power outage.

[0006] To de-ice large-diameter ground wires (low resistance) in certain heavily iced areas, ground wire de-icing requires extended or repeated de-icing, increasing transmission line outages and posing potential risks to grid safety. This high investment and costs hinder cost reduction and efficiency gains. The DC de-icing system requires large-capacity rectifiers and converters, making it expensive. This increases the initial investment and cost of deploying DC ground wire de-icing equipment. Furthermore, de-icing operations require the transmission line to be shut down to facilitate de-icing, impacting grid safety. Summary of the Invention

[0007] In view of this, an object of the present invention is to provide an overhead ground wire de-icing transformer and de-icing system for use in a non-stop power grid operation state.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] On the one hand, the present invention provides an overhead ground wire ice-melting transformer for use in a non-stop power grid operation state, comprising a transformer body, the primary winding of the transformer body being used to connect to a three-phase AC power supply ≥10kV; the voltage level of the transformer body is AC 5-10kV, and the rated capacity is 500-5000kVA; the primary winding and the secondary winding of the transformer body are arranged in pairs; in the primary winding: the two ends of the first primary winding are used to connect to phases A and B of the power system, one end of the second primary winding is electrically connected to the midpoint of the first primary winding, and the other end is connected to phase C; in the secondary winding: the first primary winding is used to be connected in series to a first power supply circuit; the second secondary winding is used to be connected in series to a second power supply circuit; the first power supply circuit and the second power supply circuit are independent of each other and each is connected in series with a load adjustment module for changing the circuit load.

[0010] Furthermore, the first power supply circuit constitutes an AC ice-melting circuit, which is used to be connected in series with the head ends of two parallel overhead ground wires to be melted, and the end connection positions of the two overhead ground wires are electrically connected with controllable on and off through a ground wire end connection controller.

[0011] Furthermore, the load adjustment module in the AC ice melting circuit is an adjustable resistor; and the load adjustment module in the second power supply circuit is a converter.

[0012] Furthermore, the load adjustment module in the AC ice melting circuit is an adjustable resistor; the load adjustment module in the second power supply circuit includes a motor and a motor drive controller, and the motor is an AC asynchronous motor.

[0013] Furthermore, the load regulation module in the second power supply circuit also includes a generator and a power storage mechanism, the input shaft of the generator is drivingly connected to the output shaft of the motor, and the electrical output interface of the generator is connected to the electrical input interface of the power storage mechanism through a cable.

[0014] Furthermore, the first power supply circuit and the second power supply circuit constitute independent AC ice melting circuits, and the two parallel overhead ground wires to be melted are independently connected in series to the first power supply circuit and the second power supply circuit; the load adjustment module is a converter or a motor and a motor drive controller.

[0015] Furthermore, it also includes a container body, and the transformer body is fixedly installed as a whole inside the container body; the outer surface of the container body is provided with an electrical interface for one-to-one electrical connection with the primary winding and the secondary winding.

[0016] On the other hand, the present invention provides an overhead ground wire de-icing system for use in a non-stop power grid state, comprising a ground wire end connection controller and the overhead ground wire de-icing transformer as described above; the ground wire end connection controller comprises a controllable on-off connection mechanism electrically connected across two parallel overhead ground wires to achieve remote on-off control.

[0017] Furthermore, the controllable on-off connection mechanism includes a shell made of hard insulating material, and the overall shape of the shell is a cylindrical structure, the two ends of the cylindrical structure are respectively electrically fixedly connected to one end of a conductive cable, and the other end of the conductive cable is electrically fixedly connected to two overhead ground wires to be melted through a clamp; the interior of the shell is provided with an axially extending and insulated partition plate, and the partition plate divides the interior of the shell into an on-off space and a control space; in the on-off space: a fixed conductor electrically connected to the end of one of the conductive cables and a movable conductor electrically connected to the end of the other conductive cable through a retractable cable are provided; in the control space: a control module, and a drive module, a communication module and a power supply module electrically connected to the control module are provided; the drive module has an action part that can extend back and forth along the axial direction of the shell, and the action part is fixedly connected to the movable conductor through an insulating connector, so that the movable conductor can be in contact with or away from the fixed conductor.

[0018] Furthermore, the on-off space is located at the upper inner portion of the outer shell, and the control space is located at the lower inner portion of the outer shell; the controllable on-off connection mechanism also includes an icing condition monitoring module connected to the control module signal, and the icing condition monitoring module includes an ambient temperature sensor, a ground temperature sensor and an icing thickness measurement sensor; the ambient temperature sensor is used to be fixedly mounted on the outer side of the outer shell, and the measuring surface is in contact with the air and is used to measure the air temperature; the ground temperature sensor is used to be fixedly mounted on the outer surface of a conductive cable exposed to the air, and the measuring surface is in contact with the outer surface of the conductive cable and is used to measure the temperature of the conductive cable; an outwardly protruding cover is provided on the outer side of the axial end of the outer shell, and a thickness measurement space is formed between the cover and the outer shell, and the icing thickness measurement sensor is fixedly arranged in the thickness measurement space and the measuring surface points to the outer surface of the conductive cable exposed to the air.

[0019] The beneficial effects of the present invention are:

[0020] 1. Compared with the prior art, the advantages of the overhead ground wire de-icing transformer used for power grid non-stop operation are:

[0021] (1) The cost of the overhead ground wire de-icing transformer in this technical solution can be lower, and the three-phase AC power grid can operate more safely without stopping during the ground wire de-icing operation, thereby better ensuring the reliability of the power grid's continuous power supply. Specifically:

[0022] In existing technology, de-icing transmission line ground wires involves using a large-capacity de-icing converter to convert AC power into DC power and apply it to the ground wire of the ice-covered transmission line. The ends of the ground wire are then short-circuited, allowing the DC current to gradually melt the ice on the ground wire through its thermal effect. Using DC de-icing requires an AC power source of 10kV or higher. After passing through a three-winding rectifier transformer, the current is fed into a 12-pulse thyristor rectifier (a unit costs approximately 40,000 to 100,000 yuan). After rectification, the DC power is output for de-icing. Therefore, deploying DC de-icing equipment requires a significant initial investment, and de-icing ground wires or OPGW (overhead ground wire composite optical cable) requires the transmission line to be shut down for de-icing.

[0023] Using the technical solution of the present invention, the AC power supply uses a dual winding with a primary and a secondary side (i.e., utilizing the working principle of a Scott balancing transformer, which costs less than 30,000 yuan) to achieve "three-phase AC to two-phase AC conversion," that is, directly converting the three-phase AC power supply into a two-phase AC voltage with equal amplitude and a phase difference of 90 degrees. When the loads on the secondary windings (the first power supply circuit and the second power supply circuit) are equal, the three-phase currents are symmetrical (with no negative sequence (negative sequence means that phase A lags phase B by 120 degrees, phase B lags phase C by 120 degrees, and phase C lags phase A by 120 degrees)).

[0024] At the same time, because the technical solution of the present invention adopts a load regulation module in both power supply circuits, the load regulation module can be used to balance the loads in the first power supply circuit and the second power supply circuit, thereby better avoiding the generation of zero-sequence current in the power grid (zero-sequence current is generated when the power grid operates asymmetrically in three phases or operates in a single phase), reducing the impact on the operation of the power grid, and better ensuring the safe operation of the power grid, thereby effectively ensuring that the power grid does not stop operating during ice melting, that is, better ensuring the reliability of the power grid's continuous power supply.

[0025] (2) The structure and wiring method of the overhead ground wire de-icing transformer in this technical solution are simpler, which simplifies the de-icing equipment and rectification and conversion process, and reduces the de-icing investment. Therefore, it can be easily deployed and used in various substations.

[0026] 2. Compared with the prior art, the overhead ground wire de-icing system of the present invention for use in a non-stop power grid operation state has the advantage that it can remotely control the on / off switching of the ends of two parallel overhead ground wires through a controllable on / off connection mechanism, thereby improving the on / off efficiency, that is, helping to improve the de-icing efficiency.

[0027] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0029] Figure 1 This is a structural diagram of the overhead ground wire ice-melting transformer used in a power grid non-stop operation state according to the present invention;

[0030] Figure 2 This is a structural diagram of the overhead ground wire ice-melting transformer used in a power grid non-stop operation state according to the present invention;

[0031] Figure 3 This is a partial wiring diagram of the overhead ground wire ice-melting transformer for use in a power grid without power outages according to the present invention;

[0032] Figure 4 The primary voltage phasor diagram of the overhead ground wire ice melting transformer used in a non-stop power grid operation state according to the present invention;

[0033] Figure 5 The secondary voltage phasor diagram of the overhead ground wire ice melting transformer used in a non-stop power grid operation state according to the present invention;

[0034] Figure 6 This is a schematic diagram of the overall wiring of the overhead ground wire ice-melting transformer for use in a power grid without stopping operation according to the present invention;

[0035] Figure 7 This is a structural schematic diagram of a container body of an overhead ground wire ice-melting transformer for use in a non-stop power grid operation state according to the present invention;

[0036] Figure 8 This is a structural schematic diagram of a container body of an overhead ground wire ice-melting transformer for use in a non-stop power grid operation state according to the present invention;

[0037] Figure 9 A schematic diagram of the installation position of the ground wire end connection controller in the overhead ground wire ice melting system of the present invention;

[0038] Figure 10 A schematic diagram of the three-dimensional structure and a partial enlarged diagram of the controllable on-off connection mechanism of the present invention;

[0039] Figure 11 A schematic diagram of the three-dimensional structure and a partial enlarged diagram of the controllable on-off connection mechanism of the present invention;

[0040] Figure 12 A schematic diagram of the three-dimensional structure of the controllable on-off connection mechanism of the present invention and a partial enlarged diagram (with the end cover disassembled);

[0041] Figure 13 A schematic diagram of the three-dimensional structure of the controllable on-off connection mechanism of the present invention and a partial enlarged diagram (with the end cover disassembled);

[0042] Figure 14 This is a structural diagram of the linear module and the fixed conductor and movable conductor parts in the controllable on-off connection mechanism of the present invention (the fixed conductor and the movable conductor are in a contact and conductive state);

[0043] Figure 15 This is a structural diagram of the linear module and the fixed conductor and movable conductor parts in the controllable on-off connection mechanism of the present invention (the fixed conductor and the movable conductor are in a separated and disconnected state);

[0044] Figure 16 Schematic diagram of the structure of the linear module and the fixed conductor and movable conductor parts in the controllable on-off connection mechanism of the present invention (the fixed conductor and the movable conductor are in a separated and disconnected state, and the movable conductor and the insulating connector are in a separated state);

[0045] Figure 17 A cross-sectional view of a fixed conductor in the controllable on / off connection mechanism of the present invention;

[0046] Reference numerals are: first primary winding W11, second primary winding W12, first primary winding W21, second primary winding W22, first primary current Iα, second secondary current Iβ; first parallel overhead ground wire E1, first parallel overhead ground wire E2, ground wire end connection controller SA1, grounding control switches SA2 and SA3, ice melting circuit control switch S4, adjustable resistor R1, converter / motor drive controller Converter, motor M, generator G, uninterruptible power supply UPS, battery BAT; Container body CT; transmission tower TT; controllable on-off connection mechanism CC: shell C1, conductive cable C2, clamp C3, partition C4, on-off space C5, fixed conductor C51, movable conductor C52, control space C6, control module C61, linear module C62, communication module C63, power supply module C64, action part C65, insulating connector C66, ambient temperature sensor C7, ground temperature sensor C8, ice thickness measurement sensor C9, cover C10, end cover C12, anemometer C13. DETAILED DESCRIPTION

[0047] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0048] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0049] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring the embodiments of the present invention.

[0050] Example 1:

[0051] like Figure 1-5As shown, this embodiment provides an overhead ground wire ice-melting transformer for use in a non-stop power grid operation state, including a transformer body, the primary winding of which is used to connect to a three-phase AC power supply ≥10kV; the voltage level of the transformer body is AC 5-10kV, and the rated capacity is 500-5000kVA; the primary winding and the secondary winding of the transformer body are arranged in pairs.

[0052] like Figure 3 As shown, in the primary winding: the two ends of the first primary winding W11 are used to connect to phases A and B of the power system, one end of the second primary winding W12 is electrically connected to the midpoint of the first primary winding W11, and the other end is connected to phase C.

[0053] In the secondary winding: the first secondary winding W21 is used to be connected in series with the first power supply circuit; the second secondary winding W22 is used to be connected in series with the second power supply circuit; the first power supply circuit and the second power supply circuit are independent of each other and each is connected in series with a load adjustment module for changing the circuit load.

[0054] like Figure 6 As shown, the first power supply circuit forms an AC ice-melting circuit, which is connected in series with the head ends of two parallel overhead ground wires (parallel first overhead ground wire E1 and parallel first overhead ground wire E2) to be melted. The terminal connection points of the two overhead ground wires are electrically connected with controllable on / off control via a ground wire terminal connection controller SA1. Parallel first overhead ground wire E1 is connected to a grounding control switch SA3 and an ice-melting circuit control switch S4, while parallel first overhead ground wire E2 is connected to a grounding control switch SA2.

[0055] During implementation, the first embodiment of the ground wire end connection controller SA1 (not shown in the accompanying drawings) is: it includes a conductor and an outdoor click-type disconnector, and the outdoor click-type disconnector is fixedly installed on the transmission tower at a position adjacent to the end of the overhead ground wire. The front and rear static contacts of the outdoor click-type disconnector are each electrically fixedly connected to the ends of the two overhead ground wires through a conductor and a clamp.

[0056] In this embodiment, the two parallel overhead ground wires to be de-iced are connected in series only to the first power supply circuit to form an AC de-icing circuit. This makes it easy for the second power supply circuit to match and adjust according to the current and load in the first power supply circuit to achieve load balancing between the first power supply circuit and the second power supply circuit. At the same time, the second power supply circuit does not need to be connected to the overhead ground wire, which simplifies the structure of the second power supply circuit, saves the cables and construction required for connecting to the de-icing circuit, and further reduces the deployment difficulty.

[0057] The load adjustment module in the AC ice-melting circuit is an adjustable resistor R1; the load adjustment module in the second power supply circuit is a converter.

[0058] The adjustable resistor R1 in the AC ice melting circuit is low in price, can adjust the load power parameters without a complex control circuit, and has a fast adjustment response.

[0059] The converter in the second power supply circuit is an off-the-shelf product. It uses power electronic devices (such as IGBTs and MOSFETs) for regulation, resulting in low energy loss. This allows for easy closed-loop control and precise load regulation using a controller and power parameter testers (such as current transformers or voltage transformers).

[0060] Example 2:

[0061] This embodiment provides an overhead ground wire ice-melting transformer for use in a power grid without stopping operation. The difference from the first embodiment is that:

[0062] The load adjustment module in the AC ice melting circuit is an adjustable resistor R1;

[0063] The load regulation module in the second power supply circuit includes a motor M and a motor drive controller, and the motor is an AC asynchronous motor.

[0064] The motor and the motor drive controller in the second power supply circuit have a large load adjustment range, and different loads can be simulated by controlling the rotational speed.

[0065] Among them, the load regulation module in the second power supply circuit also includes a generator G and a storage mechanism. The input shaft of the generator G is drive-connected to the output shaft of the motor, and the electrical output interface of the generator is connected to the electrical input interface of the storage mechanism through a cable.

[0066] During implementation, the power storage mechanism comprises an uninterruptible power supply (UPS) and a battery (BAT) or supercapacitor module. Generator G is electrically connected to a voltage regulator, which regulates the output voltage, providing a regulated input for the power storage mechanism, ensuring the safety and reliability of power generation and storage. Furthermore, this technical solution utilizes a load regulation module with generator M, enabling step-down voltage transformation on the secondary side, eliminating transformers and reducing deployment and operational costs.

[0067] After adopting the above generator and power storage mechanism, the kinetic energy of the motor can be used to generate electricity, and the power storage mechanism can be used to store the generated electricity for standby use.

[0068] Example 3:

[0069] This embodiment provides an overhead ground wire ice-melting transformer for use in a power grid without stopping operation. The difference from Embodiments 1 and 2 is that:

[0070] The first power supply circuit and the second power supply circuit constitute independent AC ice melting circuits, and the two parallel overhead ground wires to be melted are independently connected in series to the first power supply circuit and the second power supply circuit; the load adjustment module is a converter or a motor and a motor drive controller.

[0071] In this way, the two circuits on the secondary side can be used as the power source of the AC ice melting circuit at the same time. The load of the two AC ice melting circuits is the impedance of the two parallel and equidistant overhead ground wires. The load is more balanced, which can reduce the power consumption of the load regulation module.

[0072] Example 4:

[0073] This embodiment provides an overhead ground wire ice-melting transformer for use in a power grid without power outages. The embodiment differs from Embodiments 1-3 in that:

[0074] Overhead ground wire de-icing transformers used for non-stop grid operation also include containerized CTs, such as Figure 7-8 As shown, the transformer body is fixedly installed inside the container body CT; the outer surface of the container body CT is provided with an electrical interface for one-to-one electrical connection with the primary winding and the secondary winding.

[0075] The use of the above container body CT makes the lifting of the transformer body and the on-site installation process more convenient.

[0076] Preferably, the outer top side of the container body CT is fixedly installed with lifting ears or rings for lifting; the bottom has space for a forklift to insert, and the space is also convenient for the various cables typically connected to the winding to pass through smoothly and be quickly routed through the underground corridor.

[0077] Example 5:

[0078] This embodiment provides an overhead ground wire de-icing system for a non-stop power grid operation state. Figure 9 As shown, it includes a ground wire end connection controller SA1 and an overhead ground wire ice melting transformer arranged on a transmission tower TT;

[0079] The ground wire end connection controller SA1 includes a controllable on-off connection mechanism CC electrically connected across two parallel overhead ground wires to achieve remote on-off control.

[0080] like Figure 10-17 As shown, the controllable on-off connection mechanism CC includes a housing C1 made of a hard insulating material. The housing C1 has an overall cylindrical structure. The two ends of the cylindrical structure are each electrically and fixedly connected to one end of a conductive cable C2. The other end of the conductive cable C2 is electrically and fixedly connected to two overhead ground wires to be melted through a clamp C3.

[0081] An axially extending and insulated partition plate C4 is provided inside the housing. The partition plate C4 divides the interior of the housing into a switching space C5 and a control space C6.

[0082] In the on-off space C5, there are provided a fixed conductor C51 electrically connected to the end of one of the conductive cables and a movable conductor C52 electrically connected to the end of the other conductive cable via a retractable cable.

[0083] In the control space C6: a control module C61, a driving module electrically connected to the control module C61, a communication module C63 and a power supply module C4 are provided; the driving module has an action part C65 that can extend back and forth along the axial direction of the shell, and the action part C65 is fixedly connected to the movable conductor C52 through an insulating connector C66, so that the movable conductor C52 can be in contact with or connected to the fixed conductor C51 or move away from it.

[0084] By using the above-mentioned ground wire end connection controller SA1, it is possible to remotely send and receive signals through the communication module C63, receive control instructions and transmit them to the control module C61 to activate the drive module, so that the fixed conductor and the movable conductor in the on-off space can be in contact and connected or disconnected, so that the operation of connecting to melt ice or disconnecting to stop melting ice can be quickly completed according to actual conditions, making the operation more convenient, intelligent and efficient.

[0085] During implementation, end caps C12 are removably fixedly connected to each axial end face of control space C6 on the housing. End caps C12 are made of the same insulating material as housing C1. End caps C12 and the end faces of housing C1 can be fixed with screws (sealing rings can be provided on the contact surfaces) or ultrasonic welding to enhance connection reliability and sealing.

[0086] During implementation, both axial end faces of the on-off space C5 are detachably fixedly connected with a protective net (not shown in the figure). The protective net is preferably made of the same insulating material as the outer shell, which can effectively block and prevent birds from entering.

[0087] During implementation, the driving module may be an electric push rod or a motor-driven linear module C62.

[0088] During implementation, the movable conductor C52 has a conical cylindrical structure. The end surface of the fixed conductor C51 facing the movable conductor has a conical cylindrical socket for the movable conductor C52 to mate with. This not only provides a guide between the conical cylindrical socket and the conical cylindrical structure, but also allows for a larger contact area when the two are connected, improving the reliability of electrical contact.

[0089] In practice, the communication module C63 preferably adopts a 3G or 4G communication module. Solar power generation films are arranged axially on the outer surface of the housing C1, and the solar power generation films are electrically connected to the power supply module C4 and used to charge the power supply module C4.

[0090] During implementation, the conductive cable C2 and the overhead ground wire to which it is connected are made of the same material and type of wire (for example, if the overhead ground wire is LBGJ-120-20AC aluminum-clad steel stranded wire, the conductive cable is also made of LBGJ-120-20AC aluminum-clad steel stranded wire). The outer surface of the conductive cable C2 and the outer surface of the overhead ground wire to which it is connected are treated with the same surface treatment process (e.g., spraying or painting with anti-icing and snow coating). This allows the conductive cable C2 in the controllable on-off connection mechanism CC to be in the same natural environment as the overhead ground wire, resulting in the same ice and ice melting conditions. This facilitates the timely and accurate detection of ice and ice melting conditions by deploying sensors on the controllable on-off connection mechanism, enabling more accurate monitoring and data transmission of the ice and ice melting conditions, and thus enabling more precise, timely, and intelligent ice melting operations.

[0091] During implementation, the anti-ice and snow coating is an existing coating, which is mainly composed of an alternating multi-block inorganic-organic interpenetrating network polymer (IPN) base material and a high-activity nano anti-ice and snow filler that has been surface-modified. It is suitable for various coating methods, can self-curing at room temperature, and can form a 30μm dry coating film on the protected surface after coating. The dry coating film can prevent ice and snow from adhering, and the working mechanism is: the dry coating film can form a fluid interface or thin layer interface on the protected surface after the initial ice crystals adhere, so that ice cannot adhere there. The adhesion between the fluid interface or thin layer interface on the protected surface and the ice is less than 0.2Mpa, which can prevent ice and snow from adhering. At the same time, the anti-ice and snow coating also has composite functions such as corrosion resistance, wear resistance, anti-aging, and surface self-cleaning.

[0092] During implementation, the hard insulating material of the shell can be any one of silicone rubber, phenolic resin or glass fiber reinforced plastic.

[0093] During implementation, the overhead ground wire de-icing system, designed for use without grid shutdown, also includes a vacuum circuit breaker and disconnector installed on the high-voltage side of the primary winding, line ABC. It also includes current and voltage transformers for measuring the three phases A, B, C, and C, as well as current and voltage transformers for measuring the first and second power supply circuits. The components required for connecting the high-voltage and low-voltage sides of the transformer are all existing technology and have typical design and construction standards in the relevant industry, so they are not detailed here.

[0094] During implementation, the control module C61 can adopt a single-chip microcomputer (for example, an MCU of model PIC24FJ64GA705); the drive module can directly adopt a stepper motor driver, or the drive module can adopt a stepper motor drive control chip of model TMC5272 or TMC5271; the communication module C63 can adopt a LoRa wireless communication module, a 3G communication module or a 4G communication module; the power supply module C4 preferably adopts a low-temperature resistant supercapacitor battery pack.

[0095] The on-off space is located at the upper inner portion of the shell, and the control space is located at the lower inner portion of the shell.

[0096] The controllable on-off connection mechanism also includes an icing condition monitoring module connected to the control module C61 signal. The icing condition monitoring module includes an ambient temperature sensor C7, a ground temperature sensor C8, and an ice thickness measurement sensor C9.

[0097] The ambient temperature sensor C7 is fixedly mounted on the outer surface of the housing C1, with the measuring surface in contact with the air and used to measure the air temperature;

[0098] The ground wire temperature sensor C8 is used to be fixedly mounted on the outer surface of the conductive cable C2 exposed to the air, with the measuring surface in contact with the outer surface of the conductive cable C2 and used to measure the temperature of the conductive cable C2;

[0099] An outwardly protruding cover C10 is provided on the outer surface of the axial end of the shell C1, and a thickness measurement space is formed between the cover C10 and the shell C1. The ice thickness measurement sensor C9 is fixedly arranged in the thickness measurement space and the measuring surface points to the outer surface of the conductive cable exposed to the air.

[0100] This technical solution, after setting the above-mentioned icing condition monitoring module at the controllable on-off connection mechanism CC, can enable the icing condition monitoring module to obtain the most accurate icing condition parameters, thereby helping to improve the on-site anti-icing emergency response capability, accuracy and flexibility.

[0101] During implementation, the ice thickness measurement sensor uses a microwave radar sensor (for example, the WTL580-C01 microwave radar sensing module produced by Shenzhen Waytronic Electronics Co., Ltd., which can achieve a forward sensing distance of 0.1 to 20 m (adjustable), ultra-low power consumption, and an operating current as low as 18 uA or less; or the GT1500UWB system-level low-power ranging chip produced by Shenzhen Jieyang Microelectronics Co., Ltd.), an infrared ranging sensor (for example, the WTU201F2 B004 low-power infrared ranging module produced by Shenzhen Waytronic Electronics Co., Ltd., which has low power consumption and an operating current of ≤12 uA in standby mode), an ultrasonic ranging chip or a lidar (for example, the short-range single-point series lidar produced by Benewake (Beijing) Photonics Technology Co., Ltd., such as any one of the models TF-NOVA, TF-Luna, TFS20-L or TFminiPlus), and preferably, the ranging sensors are arranged in two groups at both ends of the axial direction of the housing. Because the conductive cable is the same model and size as the overhead ground wire and is located in the same natural environment, this not only improves the reliability of overhead ground wire temperature measurement through redundant configuration, but also allows for simultaneous measurement of ice thickness on both conductive cables through dual redundant configuration. This allows for more accurate and real-time information on ice thickness changes on both conductive cables and overhead ground wires (calculating ice melting rates), providing precise data support for accurate ice melting.

[0102] During implementation, the outer shell is preferably of cylindrical structure; the cover shell and the outer shell are preferably of integrally formed structure, and the shape of the cover shell on the cutting surface perpendicular to the axial center line of the outer shell is inverted V shape, and the lower edge of the inverted V shape is smoothly connected to the outer side surface of the outer shell; the cover shell is located on the outside of the axial end of the outer shell in the axial direction of the outer shell and is formed with a fixed mounting portion for exposing the transmitting and receiving head of the ice thickness measuring sensor, and the transmitting and receiving head fixed on the mounting portion is obliquely downward and points downward to the outer surface of the adjacent conductive cable exposed to the air.

[0103] This makes the outer surface of the housing more resistant to ice and snow accumulation. Similarly, the outer shape of the cover forms a surface for rain, ice, and snow to shed, providing protection against accumulation. The outer end of the mounting portion of the cover is pointed, minimizing the obstruction of ice and snow, thereby ensuring accurate measurement of ice thickness on the conductive cable. It also protects the transmitter and receiver heads of the ice thickness measurement sensor.

[0104] During implementation, both the ambient temperature sensor and the ground temperature sensor can utilize CMOS temperature sensor chips, such as the DS1621 digital temperature sensor chip manufactured by Dallas Semiconductor Corporation in the United States. This chip can accurately measure temperatures over a wide temperature range of -55°C to +125°C, with an accuracy of up to 0.5°C and reliable measurement. Furthermore, the chip operates with a voltage range of 2.7V to 5.5V, consumes low power, and helps extend the life of the device. The 8-pin DIP package occupies little space and is compact, making it suitable for mounting the ambient temperature sensor on the exterior of the housing, and for mounting the ground temperature sensor on the underside of a conductive cable.

[0105] In implementation, it is preferred that two redundant line temperature sensors be installed on the outer underside of a conductive cable connected at each end of the cylindrical structure of the housing. Because the conductive cable is the same model and size as the overhead ground wire and is located in the same natural environment, this redundant installation not only improves the reliability of overhead ground wire temperature measurement, but also allows for simultaneous temperature measurement of both conductive cables through dual redundancy, enabling more accurate and precise real-time temperature readings and temperature changes of both the conductive cable and the overhead ground wire, providing precise data support for precise ice melting.

[0106] During implementation, a lightning rod structure is preferably provided on the top of the housing, and the bottom of the lightning rod structure is electrically connected to any conductive cable through an electrical cable.

[0107] During implementation, it is preferred that a wind speed sensor (anemometer C13) is fixedly mounted on the lower exterior of the housing, and the signal output end of the wind speed sensor is electrically connected to the corresponding input interface on the control module C61.

[0108] In summary, the above-mentioned overhead ground wire de-icing system for non-stop power grid operation can obtain multiple parameters such as the actual wind speed, ambient temperature, temperature of the overhead ground wire, and ice thickness at the overhead ground wire de-icing site through a controllable on-off connection mechanism, and can thus promptly start the overhead ground wire de-icing operation when the ambient temperature is at a low wind speed on a single day, a high ambient temperature, and a low load on the power grid, and monitor the overhead ground wire itself and the thickness of its ice covering in real time, thereby realizing accurate, efficient, and safe manual or intelligent de-icing operations for the ground wire.

[0109] When the above-mentioned overhead ground wire ice melting system is used in actual use without power grid shutdown, it:

[0110] When there is no need to melt ice on the overhead ground wire, the fixed conductor and the movable conductor in the controllable on-off connection mechanism are disconnected; and the two parallel overhead ground wires are grounded respectively.

[0111] When de-icing the overhead ground wire is necessary, the fixed and movable conductors in the controllable on / off connection mechanism are connected, and AC power is introduced into the circuit to melt the ice. Based on dynamic measurements of ice coverage (such as ice thickness), the system automatically decides to start and stop de-icing, achieving intelligent AC de-icing operations.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. Overhead ground wire de-icing transformer for non-stop grid operation, characterized by: The transformer comprises a transformer body, wherein the primary winding of the transformer body is used to be connected to a three-phase AC power supply of ≥10kV; The voltage level of the transformer body is AC 5-10kV, and the rated capacity is 500-5000kVA; the primary winding and secondary winding of the transformer body are arranged in pairs; In the primary winding: the two ends of the first primary winding are used to connect to phases A and B of the power system, one end of the second primary winding is electrically connected to the midpoint of the first primary winding, and the other end is connected to phase C; In the secondary winding: the first secondary winding is used to be connected in series with the first power supply circuit; the second secondary winding is used to be connected in series with the second power supply circuit; the first power supply circuit and the second power supply circuit are independent of each other and each is connected in series with a load adjustment module for changing the circuit load.

2. The overhead ground wire ice-melting transformer for use in a power grid without stopping operation according to claim 1, characterized in that: The first power supply circuit constitutes an AC ice melting circuit, which is used to be connected in series with the head ends of two parallel overhead ground wires to be melted. The end connection positions of the two overhead ground wires are electrically connected with controllable on and off through a ground wire end connection controller.

3. The overhead ground wire ice-melting transformer for use in a power grid without stopping operation according to claim 2, characterized in that: The load adjustment module in the AC ice melting circuit is an adjustable resistor; the load adjustment module in the second power supply circuit is a converter.

4. The overhead ground wire ice-melting transformer for use in a power grid without stopping operation according to claim 2, characterized in that: The load adjustment module in the AC ice melting circuit is an adjustable resistor; the load adjustment module in the second power supply circuit includes a motor and a motor drive controller, and the motor is an AC asynchronous motor.

5. The overhead ground wire ice melting transformer for use in a power grid without stopping operation according to claim 4, characterized in that: The load regulation module in the second power supply circuit also includes a generator and a power storage mechanism. The input shaft of the generator is drivingly connected to the output shaft of the motor, and the electrical output interface of the generator is connected to the electrical input interface of the power storage mechanism through a cable.

6. The overhead ground wire ice-melting transformer for use in a power grid without stopping operation according to claim 1, characterized in that: The first power supply circuit and the second power supply circuit constitute independent AC ice melting circuits, and the two parallel overhead ground wires to be melted are independently connected in series to the first power supply circuit and the second power supply circuit; the load adjustment module is a converter or a motor and a motor drive controller.

7. The overhead ground wire ice-melting transformer for use in a power grid without stopping operation according to any one of claims 1 to 5, characterized in that: It also includes a container body, and the transformer body is fixedly installed inside the container body as a whole; the outer surface of the container body is provided with an electrical interface for electrically connecting with the primary winding and the secondary winding in a one-to-one correspondence.

8. An overhead ground wire de-icing system for use in a power grid without shutting down, characterized by: It comprises a ground wire end connection controller and the overhead ground wire ice-melting transformer according to claim 7; the ground wire end connection controller comprises a controllable on-off connection mechanism that is electrically connected across two parallel overhead ground wires and can realize remote on-off control.

9. The overhead ground wire ice melting system for non-stop grid operation according to claim 8, characterized in that: The controllable on-off connection mechanism includes a housing made of a hard insulating material. The housing has an overall cylindrical shape. The two ends of the cylindrical structure are each electrically and fixedly connected to one end of a conductive cable. The other end of the conductive cable is electrically and fixedly connected to two overhead ground wires to be melted through a clamp. An axially extending and insulating partition plate is provided inside the housing, and the partition plate divides the interior of the housing into a switching space and a control space; In the on-off space: a fixed conductor electrically connected to the end of one of the conductive cables and a movable conductor electrically connected to the end of the other conductive cable via a retractable cable are provided; In the control space: a control module, and a drive module, a communication module and a power supply module electrically connected to the control module are provided; The driving module has an action portion that can extend back and forth along the axial direction of the housing. The action portion is fixedly connected to the movable conductor through an insulating connector, so that the movable conductor can be in contact with or away from the fixed conductor.

10. The overhead ground wire ice melting system for non-stop grid operation according to claim 8, characterized in that: The on-off space is located at the upper inner portion of the shell, and the control space is located at the lower inner portion of the shell; The controllable on-off connection mechanism also includes an icing condition monitoring module connected to the control module signal, and the icing condition monitoring module includes an ambient temperature sensor, a ground temperature sensor and an ice thickness measurement sensor; The environmental temperature sensor is used to be fixedly mounted on the outer surface of the housing, with the measuring surface in contact with the air and used to measure the air temperature; The ground wire temperature sensor is used to be fixedly mounted on the outer surface of a conductive cable exposed to the air, with a measuring surface in contact with the outer surface of the conductive cable and used to measure the temperature of the conductive cable; An outwardly convex cover is provided on the outer side surface of the axial end of the shell, and a thickness measurement space is formed between the cover and the shell. The ice thickness measurement sensor is fixedly arranged in the thickness measurement space and the measuring surface points to the outer surface of the conductive cable exposed to the air.

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