Automatic voltage regulating and stabilizing device for power electronic SVR (Support Vector Register) circuit

Abstract

The invention discloses an automatic voltage regulating and stabilizing device for a power electronic SVR circuit, and belongs to the technical field of power electronics. Comprising a self-coupling voltage regulator unit, a power electronic regulation unit and a bypass unit, the self-coupling voltage regulator unit is connected in series with the power electronic regulation unit, and the bypass unit is connected in parallel with the power electronic regulation unit; the power electronic regulation unit is a unified power quality regulator with a series-parallel connection structure and comprises a series connection side module and a parallel connection side module; and a series winding and a parallel winding of the unified power quality regulator and an autotransformer of the autotransformer voltage regulator unit adopt a winding integrated structure design. According to the medium-voltage power distribution network voltage regulating device, the self-coupling voltage regulator and the unified power quality regulator (UPQC) of a series-parallel structure are deeply fused, and an integrated framework with coarse and fine regulation coordinated voltage regulation, winding integration and fault bypass redundancy is designed; the comprehensive improvement of the voltage regulation performance, the service life of the device, the electric energy quality treatment, the structure cost and the operation reliability is realized.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and more specifically, to a power electronic SVR line automatic voltage regulation and stabilization device. Background Technology

[0002] Voltage quality is one of the core indicators for the safe and stable operation of a power system. Its quality directly affects the safe operating efficiency of power equipment and the energy loss of distribution lines, while also having a crucial impact on industrial and agricultural safety and the daily electricity experience of residents. my country's medium-voltage distribution network is affected by multiple factors, including diurnal load fluctuations, seasonal load changes, excessively long power supply radius, and uneven load distribution, leading to significant fluctuations in the bus voltage of distribution lines. When the line voltage is too low, it can cause insufficient output and abnormal operation of electrical equipment; when the line voltage is too high, it can accelerate the aging of electrical equipment and even cause equipment failures and safety accidents. Therefore, achieving accurate, rapid, and stable regulation of medium-voltage distribution network line voltage is a pressing technical problem that needs to be solved during the construction and upgrading of the distribution network.

[0003] Currently, the industry mainstream adopts the following four technical solutions for voltage regulation in medium-voltage distribution networks. Each solution is based on different principles to achieve voltage regulation, but they all have obvious technical defects and limitations in practical applications: Changing the on-load tap changer of the main transformer in the substation: This solution uses the substation bus voltage as the only adjustment benchmark and changes the transformation ratio by adjusting the tap position of the main transformer to achieve voltage regulation. It cannot accurately adjust the local voltage fluctuations of the distribution line, and frequent operation of the main transformer on-load tap will significantly affect the mechanical structure and electrical performance of the main transformer, reducing the overall operational safety and service life of the main transformer. Capacitor switching voltage regulation: This solution reduces the voltage drop caused by reactive current in the line by switching capacitor banks, thereby indirectly achieving the purpose of voltage regulation. However, it is only applicable to scenarios where the voltage is too low due to excessive reactive power loss, with a narrow scope of application and a limited range of voltage regulation. It is difficult to achieve the expected voltage regulation effect for large voltage fluctuations caused by frequent load fluctuations and excessively long power supply radius. SVR automatic voltage regulator: This solution is a common method for voltage regulation in medium-voltage distribution networks. It maintains stable output voltage by automatically adjusting the transformer ratio through an autotransformer. However, it relies on the mechanical action of the on-load tap changer to switch the tap position. In the face of frequent voltage fluctuations and over-limit scenarios in the distribution network, it has problems such as slow response speed and insufficient voltage regulation flexibility. Moreover, the frequent mechanical action of the on-load tap changer will accelerate its wear and significantly shorten the service life of the switch and even the entire device. At the same time, the traditional SVR only has a single voltage regulation function and cannot achieve comprehensive power quality management of the distribution line. Voltage regulation by series compensation device: This scheme uses the capacitive reactance of series capacitors to offset the impedance in the line and uses the self-adaptability of capacitors to improve the line voltage. However, it has strict requirements on the wire diameter and load distribution of the distribution line. It has basically no regulating effect on the voltage drop at the end of the line caused by excessive line length or excessive resistance, and its applicable scenarios are limited.

[0004] In summary, existing medium-voltage distribution network voltage regulation technologies cannot simultaneously meet the practical operational requirements of distribution networks, which demand fast voltage regulation response, high voltage regulation accuracy, long device lifespan, and wide applicability. Furthermore, most existing solutions only offer a single voltage regulation function and cannot address power quality management needs such as reactive power compensation and harmonic suppression in distribution lines. Therefore, developing a voltage regulation and stabilization device that can achieve rapid and accurate voltage regulation, extend device lifespan, and provide comprehensive power management for distribution lines has become a key direction for addressing the pain points of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a power electronic SVR line automatic voltage regulation and stabilization device to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An automatic voltage regulation and stabilization device for SVR lines using power electronic technology includes an autotransformer unit, a power electronic regulation unit, and a bypass unit; The autotransformer unit is connected in series with the power electronic regulation unit, and the bypass unit is connected in parallel with the power electronic regulation unit. The power electronic regulation unit is a unified power quality regulator with a series-parallel structure, including a series side module and a parallel side module; The series windings, parallel windings, and autotransformer of the autotransformer unit of the unified power quality regulator adopt an integrated winding structure design.

[0007] Preferably, the autotransformer unit is used for bidirectional coarse adjustment of the line voltage, with a coarse adjustment accuracy of ±5% relative to the rated voltage; the power electronic regulating unit is used for bidirectional fine adjustment of the line voltage, with a fine adjustment accuracy of less than 1% relative to the rated voltage.

[0008] Preferably, the series-side module includes a series-coupled transformer and a series inverter. The output terminal of the series inverter is connected to the secondary side of the series-coupled transformer, and the primary side of the series-coupled transformer is connected in series with the output terminal of the autotransformer unit.

[0009] Preferably, the series inverter is equipped with a voltage imbalance compensation control module, which outputs a compensation voltage to offset the line voltage imbalance component.

[0010] Preferably, the parallel-side module includes a parallel inverter, wherein the AC side of the parallel inverter is connected in parallel with the line bus, and the DC side is connected to the DC side of the series inverter via a common bus.

[0011] Preferably, the parallel inverter is equipped with a composite compensation control module, which includes a reactive power compensation submodule, a three-phase current imbalance compensation submodule, and a harmonic compensation submodule.

[0012] Preferably, the bypass unit is composed of a forward and reverse thyristor and a switch. After the bypass unit is connected in parallel with the series output part of the power electronic regulation unit, it is connected in parallel with the secondary side of the series coupling transformer.

[0013] Preferably, the series inverter is a three-phase four-arm inverter, and the DC side of the series inverter is equipped with a DC capacitor energy storage module.

[0014] Preferably, the parallel inverter is a three-phase PWM rectifier inverter, and the AC side of the parallel inverter is connected in parallel with the line bus through a filter reactor.

[0015] Preferably, the winding integrated structure is a magnetic circuit sharing structure in which the series windings and parallel windings of the unified power quality regulator and the windings of the autotransformer are integrated into the same iron core.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention deeply integrates the autotransformer with the unified power quality regulator (UPQC) in series and parallel structure, and designs an integrated architecture with coarse and fine adjustment for coordinated voltage regulation, winding integration, and fault bypass redundancy. Compared with traditional medium-voltage distribution network voltage regulation devices, it achieves a comprehensive improvement in voltage regulation performance, device life, power quality management, structural cost, and operational reliability. The autotransformer unit uses bidirectional coarse adjustment of ±5% of rated voltage to deal with large voltage fluctuations in the line, while the power electronic regulation unit uses bidirectional fine adjustment of <1% of rated voltage to achieve precise voltage stabilization. The two work together to stabilize the line voltage within ±1% of the rated value. The millisecond-level response speed of the power electronic regulation unit is far superior to that of the traditional mechanical SVR, and can effectively deal with frequent small voltage fluctuations caused by day-night / seasonal load changes in the distribution network, solving the core pain points of slow response and low accuracy of traditional voltage regulation technology. The autotransformer unit undertakes most of the voltage regulation load, which reduces the regulation pressure on the power electronic regulation unit, avoids the power electronic devices from working under high load for a long time, and significantly reduces the number of on-load tap changer operations of the autotransformer, reducing its mechanical wear and making the overall design life of the device much longer than that of the traditional SVR.

[0017] (2) Using a series-parallel UPQC as the power electronic regulation unit breaks the limitation of the traditional SVR which only has a single voltage regulation function; the series side cancels the three-phase voltage imbalance component of the line through the voltage imbalance compensation control module, and the parallel side realizes reactive power compensation, three-phase current imbalance compensation, harmonic suppression and multiple current-type power quality management through the composite compensation control module. There is no need to install various power quality management equipment separately in the distribution network, reducing equipment deployment costs and space occupation. The series winding and parallel winding of the UPQC and the autotransformer of the autotransformer unit adopt the winding integrated structure design to realize magnetic circuit sharing. Compared with the traditional split design of "autotransformer + independent UPQC", the overall volume and weight of the device are significantly reduced, and the material cost of core components such as iron core and winding is reduced. At the same time, the DC side of the series inverter and the parallel inverter are connected to the same bus, eliminating the need for an independent DC energy storage unit, further simplifying the structure of the power electronic regulation unit, reducing the number of devices, reducing hardware costs, and the integrated design makes the device installation layout simpler and suitable for small installation scenarios such as outdoor distribution networks and box-type substations. A bypass unit connected in parallel with the power electronic regulation unit is set up. When the power electronic regulation unit experiences abnormal conditions such as device failure, overvoltage, or overcurrent, the bypass circuit can be quickly closed to disconnect the faulty unit from the power grid. At the same time, the autotransformer unit is kept connected to the power grid, maintaining the coarse voltage regulation function of the line. This avoids the interruption of voltage regulation or power instability in the distribution network caused by a single module failure, achieving uninterrupted power supply to the power grid and significantly improving the fault tolerance of the device in the operation of the distribution network and the overall power supply reliability of the distribution network. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Example 1: Please see Figure 1 An automatic voltage regulation and stabilization device for power electronic SVR lines is disclosed, applicable to 6kV, 10kV, and 35kV medium-voltage distribution lines. It includes an autotransformer unit, a power electronic regulating unit, and a bypass unit. The autotransformer unit is connected in series with the power electronic regulating unit, and the bypass unit is connected in parallel with the power electronic regulating unit. This overall architecture balances the needs for wide-range voltage regulation and high-precision rapid compensation. Furthermore, through the redundant design of the bypass unit, uninterrupted power supply to the grid is achieved in the event of a power electronic regulating unit failure, avoiding line voltage regulation interruption due to a single module failure, and improving the stability and fault tolerance of the device in distribution network operation.

[0021] The autotransformer unit is used for bidirectional coarse adjustment of line voltage, both boosting and bucking, with a coarse adjustment accuracy of ±5% relative to the rated voltage. It can cope with large voltage fluctuations in the distribution network and quickly adjust the line voltage to a range close to the rated voltage, laying the foundation for fine adjustment by the subsequent power electronic regulation unit. As the coarse adjustment execution component, the autotransformer unit undertakes most of the voltage regulation load, effectively reducing the regulation load of the power electronic regulation unit, while avoiding the power electronic devices from operating under high load for a long time, thus extending the service life of the power electronic devices.

[0022] The power electronic regulation unit is used for bidirectional fine regulation of line voltage, including both boost and buck adjustments, with a fine regulation accuracy of less than 1% relative to the rated voltage. This power electronic regulation unit is a unified power quality regulator (UPQC) with a series-parallel structure, comprising a series-side module and a parallel-side module. The series-side module consists of a series-coupled transformer, a three-phase four-arm inverter, and a voltage imbalance compensation control module. The DC side of the series inverter is equipped with a DC capacitor energy storage module, whose output is electrically connected to the secondary side of the series-coupled transformer. The primary side of the series-coupled transformer is connected in series with the output of the autotransformer unit. The voltage is adjusted by regulating the output voltage of the series inverter. The voltage regulation system changes the voltage across the coupling transformer, enabling millisecond-level bidirectional fine adjustment of the line voltage. Its response speed is far superior to that of traditional mechanical SVRs, and it can cope with frequent small voltage fluctuations in the distribution network. Furthermore, the voltage imbalance compensation control module can detect the line voltage imbalance component in real time and output the corresponding compensation voltage, effectively offsetting the three-phase voltage imbalance problem in the distribution network. This solves the pain point of three-phase voltage imbalance caused by uneven load distribution in medium-voltage distribution networks. At the same time, the series connection between the primary side of the series coupling transformer and the output of the autotransformer unit enables the superposition of coarse adjustment voltage and fine adjustment compensation voltage. The voltage regulation logic is simple and the regulation efficiency is high, with no additional power loss.

[0023] The parallel-side module consists of a three-phase PWM rectifier-inverter and a composite compensation control module. The AC side of the parallel inverter is connected in parallel to the line bus via a filter reactor, while the DC side is connected to the DC side of the series inverter via a common bus. This common bus design eliminates the need for separate DC energy storage units for the series and parallel inverters, simplifying the structure of the power electronic regulation unit, reducing the number of components, and lowering the hardware cost and size of the device. The composite compensation control module integrates a reactive power compensation submodule, a three-phase current imbalance compensation submodule, and a 7th and lower harmonic compensation submodule, which can respectively achieve: compensating for reactive power in the distribution network and reducing reactive voltage drop in the line; offsetting the three-phase current imbalance component in the line and improving the three-phase power supply balance of the grid; suppressing the 3rd, 5th, and 7th harmonic distortions in the distribution network, reducing the harm of harmonics to electrical equipment and the grid, and achieving comprehensive management of line current-type power quality.

[0024] The series windings, parallel windings, and autotransformer of the autotransformer unit of the unified power quality regulator adopt a winding integrated structure design. This structure is a magnetic circuit sharing structure integrated on the same iron core. The windings of the UPQC and the autotransformer are integrated on the same iron core to achieve magnetic circuit sharing. Compared with the traditional separate design of "autotransformer + independent UPQC", the overall size and weight of the device are greatly reduced, the material cost of core components such as iron core and windings is reduced, and the installation layout of the device is simplified, making it suitable for narrow installation scenarios such as outdoor distribution networks and box-type substations.

[0025] The bypass unit consists of a forward and reverse thyristor and a switch. After the bypass unit is connected in parallel with the series output of the power electronic regulation unit, it is connected in parallel with the secondary side of the series-coupled transformer. When the power electronic regulation unit experiences abnormal conditions such as device failure, overvoltage, or overcurrent, the bypass circuit can be quickly closed to disconnect the power electronic regulation unit from the power grid. At the same time, the normal connection between the autotransformer unit and the power grid is ensured. This avoids secondary impacts on the power grid caused by faulty power electronic components and maintains the coarse voltage regulation function of the device, ensuring that the voltage of the distribution network line does not experience significant instability.

[0026] The auxiliary module includes a voltage and current sampling module and a main control module. The voltage and current sampling modules are respectively set at the incoming end, outgoing end, and bus, and are used to collect grid voltage and current signals in real time and transmit them to the main control module. The main control module sends adjustment commands to the autotransformer unit and the power electronic regulation unit according to the sampling signals, while monitoring the working status of each module and controlling the opening and closing of the bypass unit.

[0027] Device core parameters The core operating parameters and adjustment precision of the device in this embodiment are as follows: Autotransformer unit: voltage regulation range is ±15% of rated voltage, bidirectional coarse adjustment accuracy is ±5% relative to rated voltage, and on-load tap changer operation time is ≤120s; Power electronic regulation unit: bidirectional fine regulation accuracy is <1% relative to rated voltage, voltage regulation response speed ≤20ms; series side voltage imbalance compensation capability is ≤5% voltage imbalance; parallel side reactive power compensation range is -50kVar~+200kVar, harmonic compensation rate ≥90% (for 3rd, 5th, and 7th characteristic harmonics), three-phase current imbalance compensation capability is ≤10% current imbalance; Bypass unit: Fault opening and closing response time ≤ 5ms, can withstand the impact of rated short-circuit current of the distribution network.

[0028] Working principle of the device The device in this embodiment achieves precise voltage stabilization and comprehensive power quality management of the distribution network through the working logic of "coarse adjustment + fine adjustment" coordinated voltage regulation, series + parallel coordinated power quality management, and fault bypass protection. The specific workflow is divided into normal voltage regulation and stabilization process, power quality management process, and fault bypass protection process.

[0029] (1) Normal voltage regulation and stabilization process When voltage fluctuations occur in the distribution network lines, the voltage sampling module collects voltage signals from the incoming and outgoing terminals in real time and transmits them to the main control module. The main control module determines whether to initiate coarse adjustment, fine adjustment, or a combination of coarse and fine adjustment modes based on the set rated voltage threshold. Coarse adjustment mode: When the line voltage fluctuation is ≥ ±5% (relative to the rated voltage), the main control module sends a command to the autotransformer unit to change the autotransformer ratio by switching the on-load tap changer, thereby achieving bidirectional coarse adjustment of the voltage and adjusting the line voltage to within ±5% of the rated voltage. Fine-tuning mode: When the line voltage fluctuation is less than ±5% (relative to the rated voltage), the main control module directly sends a command to the series side module of the power electronic regulation unit to adjust the PWM output signal of the series inverter, change the compensation voltage across the series coupling transformer, and after the compensation voltage is superimposed with the original line voltage, the output voltage is precisely maintained at the rated voltage value, with a fine-tuning accuracy of <1%; Coarse adjustment + fine adjustment mode: When the line voltage fluctuation range is > ±5%, it is first coarsely adjusted to within ±5% through the autotransformer unit, and then finely adjusted to the rated voltage through the series side module to complete the accurate voltage regulation of a large range of voltage fluctuations.

[0030] (2) Comprehensive Power Quality Management Process While regulating and stabilizing voltage, the device addresses voltage-related power quality issues through series-connected modules and current-related power quality issues through parallel-connected modules, achieving integrated power quality management, as detailed below: Voltage-type governance: The voltage sampling module detects the three-phase voltage imbalance of the distribution network in real time. When the imbalance exceeds the set threshold, the voltage imbalance compensation control module of the series inverter calculates and outputs a compensation voltage that is equal in magnitude and opposite in phase to the imbalance component based on the detection signal. This compensation voltage is connected in series to the line through the series coupling transformer to cancel the line voltage imbalance component and make the three-phase voltage balance meet the distribution network standard. Current-type power quality management: The current sampling module collects reactive current, three-phase unbalanced current, and harmonic current signals from the line bus in real time. The composite compensation control module of the parallel inverter processes these signals through various sub-modules: the reactive power compensation sub-module outputs capacitive / inductive reactive current to compensate for the reactive power of the line and reduce reactive voltage drop; the three-phase current imbalance compensation sub-module outputs unbalanced compensation current to offset the difference in three-phase currents in the line; and the harmonic compensation sub-module outputs compensation current that is equal in magnitude but opposite in phase to the harmonic current to suppress harmonic distortion in the line. The superposition of these compensation currents is then injected into the line by the parallel inverter to achieve comprehensive management of current-type power quality problems.

[0031] (3) Fault bypass protection process The main control module monitors the operating status of the power electronic regulation unit in real time. When abnormal conditions such as device failure, overvoltage, overcurrent, or overtemperature are detected in the series inverter or parallel inverter, a command is immediately sent to the bypass unit to trigger the rapid closing of the bypass switch composed of the forward and reverse thyristors and the switch, disconnecting the power electronic regulation unit from the grid circuit. At the same time, the autotransformer unit maintains its connection with the grid and continues to perform coarse voltage adjustment to ensure that the power distribution network does not experience power outages or significant voltage instability. After the fault is cleared, the bypass switch opens, the power electronic regulation unit is put back into operation, and the device resumes normal coarse and fine adjustment and power quality management functions.

[0032] Device application effect The power electronic SVR automatic voltage regulation and stabilization device of this embodiment is applied to a 10kV medium-voltage distribution line (power supply radius 5km, frequent load fluctuations). Compared with traditional mechanical SVR and independent UPQC, it achieves the following technical effects: Improved voltage regulation accuracy and response speed: The voltage at the output terminal is stabilized within ±1% of the rated voltage, and the voltage regulation response speed is ≤20ms, which can cope with the millisecond-level voltage fluctuations in the distribution network and solves the problems of slow response (120s) and low accuracy of traditional SVR. Extended device lifespan: The number of on-load tap changer operations of the autotransformer unit is reduced by more than 80%, avoiding wear caused by frequent mechanical actions, and the overall design life of the device is increased from 10 years for traditional SVRs to 15 years. Comprehensive improvement of power quality: The three-phase voltage imbalance of the line is reduced to below 3%, the three-phase current imbalance is reduced to below 5%, the distortion rate of the 3rd, 5th and 7th harmonics is reduced to below 5%, the reactive power compensation rate is ≥95%, and no other power quality management equipment needs to be installed separately. Reduced size and cost: The integrated winding structure reduces the overall size of the device by 40% compared to the traditional SVR + independent UPQC split design, reduces hardware material costs by 30%, and simplifies the installation layout, making it suitable for scenarios such as power grid box-type substations and outdoor pole-mounted installations. Improved operational stability: The redundant design of the bypass unit ensures no power supply interruption in the event of a device failure, increasing the power supply reliability of the distribution network to 99.99%.

[0033] Example 2: Device Adaptation Design for Different Voltage Levels This embodiment is an adaptation of Embodiment 1. It adjusts the parameters and structure of the device to suit the voltage levels and operational requirements of 6kV and 35kV medium-voltage distribution lines. The core structure and working principle remain the same as in Embodiment 1, with only the following adaptation design: 6kV distribution network adaptation: The autotransformer unit has a voltage regulation range of ±20% of the rated voltage and a coarse adjustment accuracy of ±5%; the power electronic regulating unit has a series side compensation voltage range of ±300V and a parallel side reactive power compensation range of -30kVar to +100kVar, with a harmonic compensation rate of ≥85%; the winding integrated structure adopts a miniaturized iron core and is compatible with 6kV distribution network outdoor pole-mounted small mounting boxes; 35kV distribution network adaptation: The autotransformer unit is equipped with a large-capacity on-load tap changer with a voltage regulation range of ±10% of the rated voltage and a coarse adjustment accuracy of ±5%; the power electronic regulating unit is equipped with a high-voltage isolation coupling transformer on the series side with a compensation voltage range of ±1750V, and the parallel side is connected to the 35kV bus through a step-up reactor with a reactive power compensation range of -200kVar to +800kVar and a harmonic compensation rate of ≥90%; the bypass unit adopts a 35kV high-voltage bypass switch to meet the insulation and withstand voltage requirements of the 35kV distribution network.

[0034] The adaptability design of this embodiment enables the device to meet the operational needs of different medium-voltage distribution networks, achieving precise voltage regulation and comprehensive power quality management through "coarse adjustment + fine adjustment," while maintaining the technical advantages of small size, low cost, and high reliability.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A power electronic SVR line automatic voltage regulation and stabilization device, characterized in that, It includes an autotransformer unit, a power electronic regulating unit, and a bypass unit; The autotransformer unit is connected in series with the power electronic regulation unit, and the bypass unit is connected in parallel with the power electronic regulation unit. The power electronic regulation unit is a unified power quality regulator with a series-parallel structure, including a series side module and a parallel side module; The series and parallel windings of the unified power quality regulator and the autotransformer of the autotransformer unit adopt an integrated winding structure design.

2. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 1, characterized in that: The autotransformer unit is used for bidirectional coarse adjustment of the line voltage, with a coarse adjustment accuracy of ±5% relative to the rated voltage; the power electronic adjustment unit is used for bidirectional fine adjustment of the line voltage, with a fine adjustment accuracy of less than 1% relative to the rated voltage.

3. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 1, characterized in that: The series-side module includes a series-coupled transformer and a series inverter. The output terminal of the series inverter is connected to the primary side of the series-coupled transformer, and the secondary side of the series-coupled transformer is connected in series with the output terminal of the autotransformer unit.

4. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 3, characterized in that: The series inverter is equipped with a voltage imbalance compensation control module, which outputs a compensation voltage to offset the line voltage imbalance component.

5. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 1, characterized in that: The parallel-side module includes a parallel inverter, wherein the AC side of the parallel inverter is connected in parallel with the line bus, and the DC side is connected to the DC side of the series inverter via a common bus.

6. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 5, characterized in that: The parallel inverter is equipped with a composite compensation control module, which includes a reactive power compensation submodule, a three-phase current imbalance compensation submodule, and a harmonic compensation submodule.

7. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 1, characterized in that: The bypass unit is composed of a forward and reverse thyristor and a switch. The bypass unit is connected in parallel with the series output of the power electronic regulation unit and then in parallel with the secondary side of the series-coupled transformer.

8. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 3, characterized in that: The series inverter is a three-phase four-bridge inverter, and the DC side of the series inverter is equipped with a DC capacitor energy storage module.

9. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 5, characterized in that: The parallel inverter is a three-phase PWM rectifier inverter, and the AC side of the parallel inverter is connected in parallel with the line bus through a filter reactor.

10. The power electronic SVR line automatic voltage regulation and stabilization device according to claim 1, characterized in that: The winding integrated structure is a magnetic circuit sharing structure in which the series windings and parallel windings of the unified power quality regulator and the windings of the autotransformer are integrated into the same iron core.

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