A high voltage power saver for a power distribution system and method of use thereof

Abstract

The present application relates to the technical field of distribution network energy saving and power quality management equipment, in particular to a high-voltage power saver for a power distribution system and a use method thereof, comprising a magnetic circuit body of three-phase equal-length closed magnetic circuit, the magnetic circuit body contains three groups of iron cores, each group of iron core contains two groups of core columns and an iron yoke, the core columns and the iron yoke of a single group of iron core form a three-dimensional frame-shaped structure, and the three groups of iron cores are distributed in an equilateral triangle space. Through the three-phase magnetic circuit being completely equal-length, the three-phase magnetic excitation imbalance problem is solved; meanwhile, a magnetostrictive damping buffer layer is additionally arranged at the spliced interface of the iron core, and a multi-stage composite buffer pad layer is arranged inside the clamp, so as to form a double-layer broadband damping structure, inhibit the magnetostrictive vibration of the iron core, reduce the spliced joint magnetic leakage, reduce the no-load loss and operation noise of the equipment, and control the harmonic distortion rate in the voltage regulation closed loop to avoid the deterioration of power quality in the voltage regulation process.

Description

Technical Field

[0001] This invention relates to the field of distribution network energy saving and power quality management equipment technology, specifically to a high-voltage energy-saving device for a power distribution system and its usage method. Background Technology

[0002] With the intelligent and large-scale development of industrial equipment, the number of frequency converters, rectifiers, and nonlinear load devices in 10kV power distribution systems has increased significantly. These devices generate a large number of 3rd, 5th, and 7th harmonics during operation, severely polluting the power quality of the grid. Simultaneously, the load of the power distribution system exhibits dynamic fluctuations, with significant differences between day and night and between peak and off-peak loads. The system often operates under light load conditions, easily leading to problems such as excessively high grid voltage, significantly increasing iron and copper losses in the power distribution equipment, and resulting in substantial energy waste. Furthermore, uneven load distribution on the user side easily causes imbalances in three-phase voltage and current, leading to excitation imbalance and severe overheating in the power distribution equipment, thus shortening its service life.

[0003] Currently, the mainstream high-voltage energy-saving and power quality management equipment on the market can be divided into three categories. The first category is the traditional laminated iron core type high-voltage energy-saving equipment. Its iron core adopts a segmented laminated structure, and the geometric lengths of the three-phase magnetic circuits are inconsistent. The magnetic circuit of the middle column is short and the magnetic circuit of the side column is long, which leads to an imbalance of the three-phase excitation current. The no-load current can reach 10%-15% of the rated current, and the no-load loss remains high. At the same time, there are many gaps in the splicing of the laminated iron core, resulting in serious magnetic leakage, large vibration and noise, complex winding process, and difficult high-voltage insulation treatment. The equipment has a high failure rate and extremely poor energy-saving and voltage stabilization effects.

[0004] The second type is the existing three-dimensional wound core transformer. Referring to CN208889436U, a triangular arrangement of the three-dimensional wound core structure is disclosed. By setting core insulating varnish, insulating sleeves, and staggered winding ends, the insulation performance of the equipment is optimized to a certain extent. However, this structure is only suitable for traditional parallel-type power transformers and cannot adapt to the special operating conditions of 10kV series-type high-voltage energy-saving devices. It lacks core structures such as dedicated harmonic shielding windings, dynamic intelligent voltage regulation, and high-voltage synchronous bypass protection. Furthermore, the core splicing interface lacks a vibration damping and buffering structure, resulting in significant vibration, noise, and magnetic leakage problems caused by magnetostriction, failing to meet the requirements for high-precision energy saving and stable operation.

[0005] The third type is conventional Z-type winding magnetic balance energy-saving equipment. Relying on the ampere-turn cancellation principle of Z-type winding, it can achieve a certain harmonic suppression effect. However, this type of equipment uses ordinary planar iron cores and has not solved the inherent defects of unequal length of three-phase magnetic circuits and high no-load loss. The magnetic circuit balance performance is poor, and the overall energy saving and power quality management effect is limited.

[0006] Based on existing technologies, current high-voltage energy-saving equipment generally suffers from the following technical shortcomings: First, the core structure design is unreasonable, resulting in magnetic circuit imbalance, severe magnetic leakage, and difficulty in solving vibration and noise problems; second, the winding structure is simple, with limited harmonic suppression effect and no quantitative harmonic control constraints; third, it relies solely on single load rate voltage regulation, without taking into account key power quality indicators such as three-phase imbalance and harmonic distortion rate, and the voltage regulation process easily deteriorates the power grid quality; fourth, the high-voltage bypass switching lacks phase synchronization control, and direct switching easily generates operational overvoltage, impacting the high-voltage winding insulation and resulting in low equipment operation safety; fifth, the technical solutions are mostly qualitative principle descriptions without quantitative mathematical model support, and prototype design relies on trial and error, resulting in poor engineering practicality; sixth, the insulation structure has insufficient adaptability, and traditional insulation solutions are designed for parallel transformers and cannot adapt to the special electric field distribution of series-connected high-voltage energy-saving devices, leading to rapid insulation aging. Summary of the Invention

[0007] The purpose of this invention is to provide a high-voltage energy-saving device for power distribution systems and its usage method to solve the above-mentioned problems. By ensuring that the three-phase magnetic circuits are of completely equal length, the problem of three-phase excitation imbalance is solved. At the same time, a magnetostrictive damping buffer layer is added at the core splicing interface, which, together with a multi-stage composite buffer pad layer on the inner side of the clamp, forms a double-layer broadband vibration reduction structure. This suppresses the magnetostrictive vibration of the core, reduces the leakage flux at the splice, reduces the no-load loss and operating noise of the equipment, and incorporates the harmonic distortion rate into the voltage regulation closed-loop constraint to avoid the deterioration of power quality during the voltage regulation process. Details are described below.

[0008] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a high-voltage energy-saving device for a power distribution system, comprising a magnetic circuit body with a three-phase equal-length closed magnetic circuit. The magnetic circuit body includes three sets of iron cores, each set of iron cores including two sets of core columns and an iron yoke. The core columns and iron yokes of a single set of iron cores enclose each other to form a three-dimensional frame structure. The three sets of iron cores are spatially distributed in an equilateral triangle, and each core column and its corresponding iron yoke are integrally and continuously wound. Adjacent core columns are interconnected through the iron yokes to form a three-dimensional closed magnetic circuit. A magnetostrictive damping buffer layer is provided at the mating interface of each set of iron cores. A winding assembly is assembled on the outside of the core columns of the magnetic circuit body. The winding assembly includes windings of the same number as the iron cores. The windings are wound around the outside of the two sets of core columns of adjacent iron cores, and the adjacent iron cores are abutted and spliced ​​into one unit.

[0009] Preferably, the winding adopts a Z-type harmonic shielding structure, including a working winding and a shielding winding; the ends of the winding are provided with a graded equal quantity staggered structure; an insulating layer is provided between the winding and the core column; the three sets of iron cores are interconnected and enclosed to form a core cavity; It also includes a clamping assembly for clamping and fixing the magnetic circuit body and the winding assembly; the clamping assembly includes a frame, a limiting plate, and a mounting plate; the frame is arranged around the outer periphery of the iron core; the limiting plate abuts against the end face of the winding; the mounting plate is located between two adjacent windings on the outer side of the frame; both the mounting plate and the limiting plate have radially arranged reinforcing ribs on their inner sides; the frame is made of non-magnetic metal, and a multi-stage composite buffer pad layer is provided on the inner side of the frame; the limiting plate is integrally formed with the frame, and the limiting plate has screw holes for axial support of the winding; It is also equipped with an electronic control unit for signal acquisition and voltage regulation. The electronic control unit includes an intelligent control module and a voltage regulation module. The intelligent control module integrates a voltage sensor, a current sensor, and a temperature acquisition unit. The temperature acquisition unit is located at the winding end and the yoke position. The intelligent control module is electrically connected to the voltage regulation module to construct a three-parameter dual closed-loop economic voltage solution model for load rate, three-phase unbalance, and total harmonic distortion. It is also equipped with a high-voltage synchronous bypass switching unit, which includes a high-voltage vacuum contactor, a mechanical interlock mechanism, and a synchronous phase detection submodule. The high-voltage synchronous bypass switching unit is connected in parallel to the input and output ends of the high-voltage energy-saving device to complete the seamless switching between the energy-saving operation mode and the bypass power supply mode.

[0010] Preferably, the magnetostrictive damping buffer layer is made of butyl-nitrile composite damping rubber with a thickness of 0.25-0.45 mm; the magnetostrictive damping buffer layer completely covers the contact surface of the iron core splicing and mating; the iron core meets the three-phase magnetic circuit equal length constraint: The no-load loss of the iron core satisfies the formula: Among them, the process coefficient It should be controlled between 1.05 and 1.1.

[0011] Preferably, the Z-type harmonic shielding winding satisfies the harmonic ampere-turn balance constraint formula: ; In the formula: Harmonic order; , These are the equivalent number of turns and the h-th harmonic current of the working winding, respectively. , These are the equivalent number of turns of the shielding winding for the h-th harmonic and the h-th harmonic current, respectively.

[0012] Preferably, the inner wall of the core cavity is coated with an insulating varnish with a thickness of 0.1-0.3 mm, and a reinforcing insulating layer is provided on the outside of the insulating varnish; a radial air gap of 0.5-1.2 mm is reserved between the reinforcing insulating layer and the winding; the reinforcing insulating layer is composed of polyimide film composite NOMEX aramid paper stacked and wound, and the thickness of the reinforcing insulating layer is 0.4-0.7 mm.

[0013] Preferably, the thickness of the reinforcing rib gradually increases from the frame towards the mounting plate or limiting plate; the multi-stage composite buffer pad layer includes an inner silicone rubber layer and an outer damping foam layer; the cross-section of the yoke is circular or fan-shaped; the connection between the yoke and the core column adopts a rounded corner transition with a radius of 8-15mm.

[0014] Preferably, the three-parameter dual closed-loop economic voltage solution model includes a load factor calculation formula: ; For real-time load rate, For real-time active load power, This refers to the rated capacity of the device. The voltage output rule is: when The output voltage is reduced by 3% to 5% compared to the rated voltage; when The output voltage is maintained at the rated voltage; when The output voltage is linearly interpolated to adjust with the load rate; at the same time, a mandatory constraint is imposed on the three-phase current imbalance. Total Harmonic Distortion When the measured parameters exceed the limits, the output voltage should be corrected first.

[0015] Preferably, when the temperature acquisition unit detects that the winding or core temperature exceeds the preset protection threshold, the intelligent control module triggers the high-voltage synchronous bypass switching unit, waits for the input and output voltage phase synchronization moment to engage the bypass, and outputs a fault alarm signal.

[0016] Preferably, the graded, equal-quantity, staggered winding ends have an equal number of ports in the upper and lower halves of the winding, arranged in an alternating pattern to avoid short circuits at the winding ends.

[0017] The present invention also provides a method for using the high-voltage energy-saving device of the power distribution system, comprising the following steps: S1. Equipment installation and fixing: Connect the high-voltage energy-saving device body in series to the 10kV user-side power distribution circuit, and connect the high-voltage synchronous bypass switching unit in parallel to the input and output ends of the energy-saving device; use the mounting plates of the clamp assembly to fasten the whole machine; connect the voltage sensor, current sensor, and temperature acquisition unit to the secondary signal circuit to complete the mechanical verification and high-voltage insulation withstand voltage pre-test; S2. Power-on self-test: When the upstream high-voltage power supply is closed, the intelligent control module performs a power-on self-test, collects three-phase voltage, three-phase current, and temperature signals, and verifies the status of the high-voltage synchronous bypass switching unit; if the self-test is fault-free, it enters the power-saving operation mode; if the self-test is abnormal, it directly switches to bypass power supply. S3, Dual Closed-Loop Real-Time Control Operation: The intelligent control module collects electrical parameters in real time, calculates the load rate, three-phase imbalance, and total harmonic distortion rate, inputs them into the three-parameter dual closed-loop economic voltage solution model, and outputs commands to the voltage regulation module; relying on the three-dimensional closed magnetic circuit and Z-type harmonic shielding winding to cancel high-order harmonic magnetic flux and balance the three-phase excitation current. S4. Status monitoring and fault diagnosis: Continuously monitor temperature, voltage, current, and power quality indicators; when over-temperature, over-current, severe three-phase imbalance, or THD over-limit faults occur, wait for phase synchronization to execute bypass switching and output alarm; S5. Repair and recovery process: After troubleshooting, confirm the hardware insulation status, check the input and output phase synchronization, exit the bypass, and re-enter the power saving operation mode. S6. Shutdown operation: First switch to bypass power supply, then disconnect the upstream high-voltage circuit breaker to complete the power outage of the entire machine.

[0018] The beneficial effects are as follows: 1. The present invention achieves complete equal length of the three-phase magnetic circuit through the equilateral triangular three-dimensional closed magnetic circuit structure, which solves the problem of three-phase excitation imbalance from the root. At the same time, a special magnetostrictive damping buffer layer is added at the iron core splicing interface, which, together with the multi-stage composite buffer pad layer on the inner side of the clamp, forms a double-layer broadband vibration reduction structure, which effectively suppresses the magnetostrictive vibration of the iron core, reduces the leakage magnetic flux at the splice, and significantly reduces the no-load loss and operating noise of the equipment. Compared with traditional laminated iron cores and ordinary flat wound iron cores, the performance is significantly improved.

[0019] 2. Based on the harmonic cancellation principle of Z-type winding, a dedicated harmonic ampere-turn balance mathematical model is formed to achieve the cancellation of the 3rd, 5th, and 7th major high-order harmonics, solving the defects of qualitative treatment and unstable effect of traditional equipment; at the same time, the harmonic distortion rate is incorporated into the voltage regulation closed-loop constraint to avoid the deterioration of power quality during the voltage regulation process, and the harmonic treatment effect is controllable and quantifiable.

[0020] 3. The traditional single load rate voltage regulation mode is changed. The dual constraints of three-phase unbalance and total harmonic distortion are introduced to form a three-parameter dual closed-loop voltage regulation model, which is adapted to the complex fluctuation of industrial power grid. While achieving energy saving by reducing voltage under light load, it can ensure the power quality indicators of the power grid and take into account both energy saving and power supply stability.

[0021] 4. A high-voltage synchronous bypass switching unit is added, which realizes impact-free switching through phase synchronization detection, solving the problem of operation overvoltage and damage to high-voltage insulation caused by bypass switching of traditional equipment; coupled with multi-point temperature monitoring and automatic bypass protection functions, it realizes real-time fault response and improves the operational safety of equipment under 10kV high-voltage series conditions.

[0022] 5. Based on the electric field distribution characteristics of 10kV series equipment, a composite insulation structure consisting of core cavity insulating varnish, reinforced insulation layer, and radial air gap is adopted, along with graded and equal high and low staggered winding ends, to improve electrical creepage distance, avoid short circuits at winding ends, adapt to high-voltage series operation conditions, and reduce the risk of insulation aging. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall main structure of the present invention; Figure 2 This is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 3 This is an exploded view of the structure of the present invention. Figure 4 This is a schematic diagram of the three-dimensional structure of the three-dimensional wound iron core unit of the present invention; Figure 5 This is a top view of the overall structure of the present invention; Figure 6 This is a schematic diagram of the Z-type harmonic shielding winding connection method of the present invention; Figure 7 This is a schematic diagram of the harmonic shielding winding wiring structure of the present invention; Figure 8 shows the stacked iron core ( Figure 8b ), flat coiled iron core ( Figure 8c ), three-dimensional rolled iron core ( Figure 8a A comparative diagram of the magnetic circuit performance of three types of iron core structures; Figure 9 This is a schematic diagram of the actual structure of the three-dimensional wound iron core of the present invention; Figure 10 A schematic diagram comparing the voltage waveforms of phase A of the power grid before and after harmonic mitigation; Figure 11 This is a schematic diagram comparing the voltage waveforms of phase A of the power grid after harmonic mitigation. Figure 12 This is a simplified schematic diagram of the overall assembly of the iron core, winding, and clamping parts of the present invention.

[0025] The annotations in the attached figures are explained as follows: 1. Iron core; 101. Core column; 102. Iron yoke; 2. Winding; 3. Clamping piece; 301. Frame; 302. Limiting piece; 303. Mounting piece; 304. Reinforcing rib; 4. Core cavity. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0027] It should be noted that all directional and positional terms used in this invention, such as "up," "down," "left," "right," "front," "back," "vertical," "horizontal," "inner," "outer," "top," "lower," "lateral," "longitudinal," and "center," are only used to explain the relative positional relationships and connections between components in a specific state (as shown in the accompanying drawings). They are merely for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0028] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0030] See Figures 1-12As shown, this invention provides a high-voltage energy-saving device for power distribution systems, suitable for series connection in 10kV power distribution circuits. It includes a magnetic circuit body with a three-phase equal-length closed magnetic circuit. The magnetic circuit body comprises three sets of iron cores 1, each set of iron cores 1 including two sets of core posts 101 and yokes 102. The core posts 101 and yokes 102 of a single set of iron cores form a three-dimensional frame structure, used to construct a regular, closed single-phase magnetic circuit channel, ensuring uniform and stable magnetic flux transmission in a single set of iron cores. The three sets of iron cores 1 are spatially distributed in an equilateral triangle. Each core post 101 and its corresponding yoke 102 are integrally and continuously wound. Adjacent core posts 101 are interconnected through yokes 102 to form a three-dimensional closed magnetic circuit, thereby achieving completely equal geometric lengths of the three-phase magnetic circuit and eliminating three-phase interference at the source. To address excitation imbalance, the system reduces no-load current and no-load loss. A magnetostrictive damping buffer layer is installed at the interface where each set of iron cores is joined, absorbing the magnetostrictive vibration generated by alternating excitation of the iron cores, suppressing magnetic leakage through the iron core joints, and reducing equipment operating noise and magnetic loss. A winding assembly is mounted outside the core column of the magnetic circuit body to achieve electromagnetic coupling transformation based on the magnetic circuit body, completing the functions of grid voltage regulation and harmonic suppression. The winding assembly includes windings 2 in the same number as the iron cores. These windings 2 are wound around the outside of two sets of core columns 101 of adjacent iron cores 1, abutting and joining the adjacent iron cores 1 together. This winding fastening effect strengthens the overall structural rigidity of the iron cores and simultaneously enables electromagnetic linkage matching of multiple iron cores.

[0031] As an optional implementation, the winding 2 adopts a Z-type harmonic shielding structure, including a working winding and a shielding winding; the ends of the winding 2 are provided with a graded equal-quantity staggered structure, thereby effectively increasing the electrical creepage distance at the winding ends, balancing the electric field distribution at the ends, and avoiding breakdown and short-circuit faults caused by electric field concentration under high-voltage conditions; an insulation layer is provided between the winding 2 and the core column 101; the three sets of iron cores 1 are interconnected to form a core cavity 4, which is used to reserve insulation and heat dissipation space, organize the internal layout of the equipment, and at the same time improve the overall high-voltage insulation performance in conjunction with the multi-layer insulation structure; A clamping assembly 3 is also provided to clamp and fix the magnetic circuit body and the winding assembly; the clamping assembly 3 includes a frame 301, a limiting piece 302, and a mounting piece 303; the frame 301 is arranged around the outer periphery of the iron core 1 to fully wrap and limit the magnetic circuit body and the winding assembly, improve the overall structural stability, and resist the influence of external vibration; the limiting piece 302 abuts against the end face of the winding 2; the mounting piece 303 is set between two adjacent windings 2 outside the frame 301, thereby realizing bidirectional positioning of the winding in both the circumferential and axial directions, and preventing the winding from shifting or loosening during equipment operation; the inner sides of the mounting piece 303 and the limiting piece 302 All components are equipped with radially arranged reinforcing ribs 304 to enhance the overall structural strength and load-bearing capacity of the clamps, distribute stress, and prevent deformation during long-term operation. The frame 301 is made of non-magnetic metal, and a multi-stage composite buffer pad is set on the inner side of the frame 301 to adapt to the wide-frequency vibration mode of the three-dimensional iron core, achieve full-band vibration reduction and noise reduction, and further weaken the transmission of magnetostrictive vibration to the entire housing. The limiting plate 302 is integrally formed with the frame 301. The limiting plate 302 has screw holes for axial support of the winding, which is used to accurately lock the axial position of the winding, limit the winding movement, and ensure the assembly accuracy and operational stability of the high-voltage winding. It is also equipped with an electronic control unit for signal acquisition and voltage regulation. The electronic control unit includes an intelligent control module and a voltage regulation module. The intelligent control module integrates a voltage sensor, a current sensor, and a temperature acquisition unit. The temperature acquisition unit is located at the end of winding 2 and at the position of yoke 102. The intelligent control module is electrically connected to the voltage regulation module to construct a three-parameter dual closed-loop economic voltage solution model with load rate, three-phase imbalance, and total harmonic distortion rate. This breaks through the limitations of traditional single load rate voltage regulation, takes into account both energy saving effect and power grid quality, and achieves accurate and adaptive voltage regulation under complex operating conditions. It is also equipped with a high-voltage synchronous bypass switching unit, which includes a high-voltage vacuum contactor, a mechanical interlock mechanism, and a synchronous phase detection submodule. This unit is used to achieve reliable switching of the high-voltage circuit, mechanical anti-misoperation, and accurate voltage phase comparison. The high-voltage synchronous bypass switching unit is connected in parallel to the input and output of the high-voltage energy-saving device. It is used to complete the shockless switching between the energy-saving operation mode and the bypass power supply mode. With this configuration, the high-voltage switching operation overvoltage can be eliminated through the cooperation of phase synchronization detection and mechanical and electrical dual interlocks, protecting the high-voltage insulation of the equipment and ensuring uninterrupted power supply to the power distribution system. The magnetostrictive damping buffer layer is made of butyl-nitrile composite damping rubber with a thickness of 0.25-0.45mm, thus possessing both excellent damping and vibration absorption performance and high voltage and aging resistance. The thin-layer structure does not affect the magnetic flux transmission of the magnetic circuit. The magnetostrictive damping buffer layer completely covers the contact surface of the iron core assembly. The iron core meets the three-phase magnetic circuit equal length constraint to ensure balanced and consistent three-phase excitation current, completely solving the problem of unbalanced three-phase voltage and current in traditional equipment. Specifically: The no-load loss of the iron core satisfies the formula: Among them, the process coefficient By controlling the value between 1.05 and 1.1, the additional losses caused by the processing and assembly of the iron core can be reduced. The no-load loss is far superior to that of traditional laminated iron core equipment, and the magnetic circuit stability is stronger, with extremely low energy efficiency decay during long-term operation. The Z-type harmonic shielding winding satisfies the harmonic ampere-turn balance constraint formula: In the formula: Harmonic order; 、 These are the equivalent number of turns and the h-th harmonic current of the working winding, respectively. , These are the equivalent number of turns for the h-th harmonic of the shielding winding and the h-th harmonic current, respectively. By setting them up in this way, the main high-order harmonics such as the 3rd, 5th, and 7th harmonics can be precisely suppressed through the ampere-turn cancellation principle, quantifying the harmonic control effect and avoiding harmonic pollution of the power grid and equipment damage. The inner wall of the core cavity 4 is coated with an insulating varnish with a thickness of 0.1-0.3mm. A reinforcing insulating layer is set on the outside of the insulating varnish to form basic insulation protection, seal the tiny gaps in the iron core, and prevent partial discharge. A radial air gap of 0.5-1.2mm is reserved between the reinforcing insulating layer and the winding 2, thereby utilizing the air insulation characteristics to improve the overall electrical creepage distance, enhance the high voltage withstand capability, and facilitate internal ventilation and heat dissipation. The reinforcing insulating layer is composed of polyimide film composite NOMEX aramid paper, with a thickness of 0.4-0.7mm. This setting facilitates the construction of a high-strength, high-temperature resistant, and high-voltage resistant composite insulation system, which is suitable for the harsh working conditions of 10kV high-voltage series connection and delays insulation aging. The thickness of the reinforcing rib 304 gradually increases from the frame 301 towards the mounting plate 303 or the limiting plate 302, thereby achieving a uniform transition of the force gradient, concentrating the bearing of the vibration stress of the winding and the iron core, and avoiding structural cracking caused by local stress concentration. The multi-stage composite buffer pad layer includes an inner silicone rubber layer and an outer damping foam layer, which combines the high elasticity of silicone rubber and the wide-frequency vibration absorption advantages of damping foam to achieve double-layer composite vibration reduction, adapting to the multi-stage vibration modes of the iron core. The cross-section of the yoke 102 is circular or fan-shaped, preferably a fan-shaped structure, which is suitable for the triangular iron core layout and the magnetic flux distribution is more uniform. The connection between the yoke 102 and the core column 101 adopts a rounded corner transition with a radius of 8-15mm, which is used to reduce the magnetic resistance at the corner of the magnetic circuit, avoid local magnetic flux accumulation and magnetic saturation, and further reduce magnetic circuit loss. The three-parameter dual-closed-loop economic voltage solution model includes a load rate calculation formula: ; For real-time load rate, For real-time active load power, This refers to the rated capacity of the device. The voltage output rule is: when The output voltage is reduced by 3% to 5% compared to the rated voltage; when The output voltage is maintained at the rated voltage; when The output voltage is linearly interpolated to adjust with the load rate; at the same time, a mandatory constraint is imposed on the three-phase current imbalance. Total Harmonic Distortion When measured indicators exceed limits, the output voltage is corrected first, thereby achieving voltage reduction and energy saving under light load conditions and ensuring stable power supply under heavy load conditions. At the same time, power quality indicators are strictly controlled to prevent the voltage regulation process from deteriorating the grid conditions. When the temperature acquisition unit detects that the winding or core temperature exceeds the preset protection threshold, the intelligent control module triggers the high-voltage synchronous bypass switching unit, waits for the input and output voltage phase synchronization moment to put the bypass into operation, and outputs a fault alarm signal, thereby realizing accurate prediction and seamless switching of equipment overheating faults, avoiding high temperature burning of windings and cores, and ensuring the safe operation of equipment and power grid. The graded, equal-quantity, staggered winding ends have an equal number of ports in the upper and lower halves of the winding, arranged in an alternating pattern to avoid short circuits at the winding ends. This, in turn, regulates the electric field distribution at the winding ends, eliminates the potential for concentrated potential differences at the ends, and improves the operational reliability and insulation safety of the high-voltage winding.

[0032] A method for using a high-voltage energy-saving device in a power distribution system includes the following steps: S1. Equipment installation and fixing: Connect the high-voltage energy-saving device body in series to the 10kV user-side power distribution circuit, and connect the high-voltage synchronous bypass switching unit in parallel to the input and output ends of the energy-saving device; use the mounting plate 303 of the clamp assembly 3 to fasten the whole machine; connect the voltage sensor, current sensor, and temperature acquisition unit to the secondary signal circuit to complete the mechanical verification and high-voltage insulation withstand voltage pre-test; S2. Power-on self-test: When the upstream high-voltage power supply is closed, the intelligent control module performs a power-on self-test, collects three-phase voltage, three-phase current, and temperature signals, and verifies the status of the high-voltage synchronous bypass switching unit; if the self-test is fault-free, it enters the power-saving operation mode; if the self-test is abnormal, it directly switches to bypass power supply. S3, Dual Closed-Loop Real-Time Control Operation: The intelligent control module collects electrical parameters in real time, calculates the load rate, three-phase imbalance, and total harmonic distortion rate, inputs them into the three-parameter dual closed-loop economic voltage solution model, and outputs commands to the voltage regulation module; relying on the three-dimensional closed magnetic circuit and Z-type harmonic shielding winding to cancel high-order harmonic magnetic flux and balance the three-phase excitation current. S4. Status monitoring and fault diagnosis: Continuously monitor temperature, voltage, current, and power quality indicators; when over-temperature, over-current, severe three-phase imbalance, or THD over-limit faults occur, wait for phase synchronization to execute bypass switching and output alarm; S5. Repair and recovery process: After troubleshooting, confirm the hardware insulation status, check the input and output phase synchronization, exit the bypass, and re-enter the power saving operation mode. S6. Shutdown operation: First switch to bypass power supply, then disconnect the upstream high-voltage circuit breaker to complete the power outage of the entire machine.

[0033] By using an equilateral triangular three-dimensional closed magnetic circuit structure, the three-phase magnetic circuits are made to be of completely equal length, thus solving the problem of three-phase excitation imbalance at its root. At the same time, a dedicated magnetostrictive damping buffer layer is added to the core splicing interface, which, together with the multi-stage composite buffer pad layer on the inner side of the clamp, forms a double-layer broadband vibration reduction structure. This effectively suppresses the magnetostrictive vibration of the core, reduces magnetic leakage at the splice, and significantly reduces the no-load loss and operating noise of the equipment. Compared with traditional laminated cores and ordinary flat wound cores, the performance is significantly improved.

[0034] Based on the harmonic cancellation principle of Z-type winding, a dedicated harmonic ampere-turn balance mathematical model is formed to achieve the cancellation of the 3rd, 5th, and 7th major high-order harmonics, solving the defects of qualitative treatment and unstable effect of traditional equipment; at the same time, the harmonic distortion rate is incorporated into the voltage regulation closed-loop constraint to avoid the deterioration of power quality during the voltage regulation process, and the harmonic treatment effect is controllable and quantifiable.

[0035] The traditional single load rate voltage regulation mode is changed. The dual constraints of three-phase unbalance and total harmonic distortion are introduced to form a three-parameter dual closed-loop voltage regulation model, which is adapted to the complex fluctuation of industrial power grids. While achieving energy saving by reducing voltage under light load, it can also ensure the power quality indicators of the power grid, taking into account both energy saving and power supply stability.

[0036] A high-voltage synchronous bypass switching unit is added, which achieves shock-free switching through phase synchronization detection, solving the problems of operational overvoltage and damage to high-voltage insulation caused by bypass switching of traditional equipment; coupled with multi-point temperature monitoring and automatic bypass protection functions, it realizes real-time fault response and improves the operational safety of equipment under 10kV high-voltage series conditions.

[0037] Based on the electric field distribution characteristics of 10kV series equipment, a composite insulation structure consisting of core cavity insulating varnish, reinforced insulation layer, and radial air gap is adopted, along with graded and equal high and low staggered winding ends, to improve electrical creepage distance, avoid short circuits at winding ends, adapt to high-voltage series operation conditions, and reduce the risk of insulation aging.

[0038] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-voltage energy-saving device for a power distribution system, suitable for series connection in a 10kV power distribution circuit, characterized in that, The magnetic circuit body includes a three-phase equal-length closed magnetic circuit. The magnetic circuit body includes three sets of iron cores (1). Each set of iron cores (1) includes two sets of core posts (101) and iron yokes (102). The core posts (101) and iron yokes (102) of a single set of iron cores enclose each other to form a three-dimensional frame structure. The three sets of iron cores (1) are spatially distributed in an equilateral triangle. Each core post (101) and the corresponding iron yoke (102) are integrally and continuously wound. Adjacent core posts (101) are interconnected through iron yokes (102) to form a three-dimensional closed magnetic circuit. A magnetostrictive damping buffer layer is provided at the docking interface where each set of iron cores is spliced ​​together. The core posts of the magnetic circuit body are equipped with winding assemblies. The winding assemblies include windings (2) with the same number as the iron cores. The windings (2) are wound around the two sets of core posts (101) of adjacent iron cores (1) and abut against each other to splice the adjacent iron cores (1) into one.

2. The high-voltage energy-saving device for a power distribution system according to claim 1, characterized in that, The winding (2) adopts a Z-type harmonic shielding structure, including a working winding and a shielding winding; the ends of the winding (2) are provided with a graded equal quantity high and low staggered structure; an insulating layer is provided between the winding (2) and the core column (101); the three sets of iron cores (1) are interconnected to form a core cavity (4). A clamping assembly (3) is also provided to clamp and fix the magnetic circuit body and the winding assembly; the clamping assembly (3) includes a frame (301), a limiting piece (302) and a mounting piece (303); the frame (301) is arranged around the outer periphery of the iron core (1); the limiting piece (302) abuts against the end face of the winding (2); the mounting piece (303) is arranged between two adjacent windings (2) outside the frame (301); the mounting piece (303) and the limiting piece (302) are both provided with radially arranged reinforcing ribs (304); the frame (301) is made of non-magnetic metal, and a multi-stage composite buffer pad is provided on the inner side of the frame (301); the limiting piece (302) is integrally formed with the frame (301), and the limiting piece (302) has screw holes for axial support of the winding; It is also equipped with an electronic control unit for signal acquisition and voltage regulation. The electronic control unit includes an intelligent control module and a voltage regulation module. The intelligent control module integrates a voltage sensor, a current sensor, and a temperature acquisition unit. The temperature acquisition unit is located at the end of the winding (2) and the position of the yoke (102). The intelligent control module is electrically connected to the voltage regulation module to construct a three-parameter dual closed-loop economic voltage solution model with load rate, three-phase unbalance and total harmonic distortion. It is also equipped with a high-voltage synchronous bypass switching unit, which includes a high-voltage vacuum contactor, a mechanical interlock mechanism, and a synchronous phase detection submodule; The high-voltage synchronous bypass switching unit is connected in parallel to the input and output ends of the high-voltage energy-saving device to complete the seamless switching between the energy-saving operation mode and the bypass power supply mode.

3. A high-voltage energy-saving device for a power distribution system according to claim 2, characterized in that, The magnetostrictive damping buffer layer is made of butyl-nitrile composite damping rubber with a thickness of 0.25-0.45 mm; the magnetostrictive damping buffer layer completely covers the contact surface of the iron core splicing and mating; the iron core meets the three-phase magnetic circuit equal length constraint: The no-load loss of the iron core satisfies the formula: Among them, the process coefficient It should be controlled between 1.05 and 1.

1.

4. A high-voltage energy-saving device for a power distribution system according to claim 3, characterized in that, The Z-type harmonic shielding winding satisfies the harmonic ampere-turn balance constraint formula: ; In the formula: Harmonic order; 、 These are the equivalent number of turns and the h-th harmonic current of the working winding, respectively. , These are the equivalent number of turns of the shielding winding for the h-th harmonic and the h-th harmonic current, respectively.

5. A high-voltage energy-saving device for a power distribution system according to claim 4, characterized in that, The inner wall of the core cavity (4) is coated with an insulating varnish with a thickness of 0.1-0.3mm, and a reinforcing insulating layer is provided on the outside of the insulating varnish; a radial air gap of 0.5-1.2mm is reserved between the reinforcing insulating layer and the winding (2); the reinforcing insulating layer is made of polyimide film composite NOMEX aramid paper stacked and wound, and the thickness of the reinforcing insulating layer is 0.4-0.7mm.

6. A high-voltage energy-saving device for a power distribution system according to claim 2, characterized in that, The thickness of the reinforcing rib (304) gradually increases from the frame (301) toward the mounting plate (303) or the limiting plate (302); the multi-stage composite buffer pad layer includes an inner silicone rubber layer and an outer damping foam layer; the cross-section of the yoke (102) is circular or fan-shaped; the connection between the yoke (102) and the core column (101) adopts a rounded corner transition with a radius of 8-15mm.

7. A high-voltage energy-saving device for a power distribution system according to claim 6, characterized in that, The three-parameter dual-closed-loop economic voltage solution model includes a load rate calculation formula: ; For real-time load rate, For real-time active load power, This refers to the rated capacity of the device. The voltage output rule is: when The output voltage is reduced by 3% to 5% compared to the rated voltage; when The output voltage is maintained at the rated voltage; when The output voltage is linearly interpolated to adjust with the load rate; at the same time, a mandatory constraint is imposed on the three-phase current imbalance. Total Harmonic Distortion When the measured parameters exceed the limits, the output voltage should be corrected first.

8. A high-voltage energy-saving device for a power distribution system according to claim 2, characterized in that, When the temperature acquisition unit detects that the winding or core temperature exceeds the preset protection threshold, the intelligent control module triggers the high-voltage synchronous bypass switching unit, waits for the input and output voltage phase synchronization moment to engage the bypass, and outputs a fault alarm signal.

9. A high-voltage energy-saving device for a power distribution system according to claim 2, characterized in that, The graded, equal-quantity, staggered winding ends have an equal number of ports in the upper and lower halves of the winding, arranged in an alternating pattern to avoid short circuits at the winding ends.

10. A method of using a high-voltage energy-saving device in a power distribution system as described in any one of claims 2-9, characterized in that, Includes the following steps: S1. Equipment installation and fixing: Connect the high voltage energy-saving device body in series to the 10kV user side power distribution circuit, and connect the high voltage synchronous bypass switching unit in parallel to the input and output ends of the energy-saving device; use the mounting plate (303) of the clamp assembly (3) to fasten the whole machine; connect the voltage sensor, current sensor and temperature acquisition unit to the secondary signal circuit to complete the mechanical verification and high voltage insulation withstand voltage pre-test; S2. Power-on self-test: When the upstream high-voltage power supply is closed, the intelligent control module performs a power-on self-test, collects three-phase voltage, three-phase current, and temperature signals, and verifies the status of the high-voltage synchronous bypass switching unit; if the self-test is fault-free, it enters the power-saving operation mode; if the self-test is abnormal, it directly switches to bypass power supply. S3, Dual Closed-Loop Real-Time Control Operation: The intelligent control module collects electrical parameters in real time, calculates the load rate, three-phase imbalance, and total harmonic distortion rate, inputs them into the three-parameter dual closed-loop economic voltage solution model, and outputs commands to the voltage regulation module; relying on the three-dimensional closed magnetic circuit and Z-type harmonic shielding winding to cancel high-order harmonic magnetic flux and balance the three-phase excitation current. S4. Status monitoring and fault diagnosis: Continuously monitor temperature, voltage, current, and power quality indicators; when over-temperature, over-current, severe three-phase imbalance, or THD over-limit faults occur, wait for phase synchronization to execute bypass switching and output alarm; S5. Repair and recovery process: After troubleshooting, confirm the hardware insulation status, check the input and output phase synchronization, exit the bypass, and re-enter the power saving operation mode. S6. Shutdown operation: First switch to bypass power supply, then disconnect the upstream high-voltage circuit breaker to complete the power outage of the entire machine.

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