Rural power grid low voltage boosting device and voltage boosting method

Abstract

The invention relates to the technical field of intelligent rural power grids, in particular to a rural power grid low-voltage boosting device and a voltage boosting method.The rural power grid low-voltage boosting device comprises a voltage boosting device body connected with a user metering box, the voltage boosting device body is mainly composed of a low-voltage controller, an alternating-current contactor, a miniature circuit breaker and a separate compensation capacitor, and the rural power grid low-voltage boosting device is small in size and high in reliability. The voltage boosting device body is mounted on a telegraph pole within 10 meters close to a user or at the front end of a user metering box, so that the power utilization voltage of the user is stabilized by utilizing the compensation characteristic and the capacitance boosting effect of the separate compensation capacitor, and normal use of household appliances of the user is guaranteed; through cooperation of the low-voltage controller capable of being controlled by the single-chip microcomputer and the alternating current contactor, remote control and automatic control over the electricity utilization voltage of a user are achieved, networking control can be conducted through 4G / 5G communication, the voltage condition of the user can be remotely obtained, and the electricity utilization low voltage of the user is effectively improved through the compensation characteristic and the capacitance rising effect of the separate compensation capacitor.

Description

Technical Field

[0001] The invention belongs to the technical field of intelligent agricultural power grids, and in particular relates to an agricultural power grid low-voltage boosting device and a voltage boosting method. Background Art

[0002] The rural power grid low voltage booster is a device designed to solve the problem of low voltage in rural power grids. The main purpose of this device is to increase the voltage level of the power grid, thereby ensuring that rural residents can use electricity stably and safely. The structure of the rural power grid low voltage booster usually includes the first connecting wire column, voltage monitor, transformer, controller body, transmission guide column and second connecting wire column. These parts are carefully designed and combined to enable the device to effectively increase the voltage.

[0003] After searching, the Chinese patent application number is 201910776236.7, which discloses a low-voltage boosting device for rural power grids, including an electrically connected single-phase EN series controller, a line protection unit and a capacitor, a thyristor composite switch circuit, a molded case circuit breaker, a lightning arrester and a current transformer. The controller adopts feedback monitoring, takes the real-time voltage of the load as the switching physical quantity, completes signal data acquisition, calculation, and control output within 20ms, and completes zero current input within less than 10ms after the switching switch receives the switching instruction. There is no inrush current and no impact on the power grid to ensure real-time tracking switching. The device of the invention has a short response time, good voltage boosting effect, and high compensation accuracy, and ultimately achieves the purpose of stabilizing the terminal voltage of the system and increasing the voltage qualification rate.

[0004] However, the above-mentioned rural power grid low voltage boosting device still has the following defects:

[0005] When the rural power grid boosting device is used for power users who are far away from the distribution transformer, have thin power supply lines and poor voltage quality, it is not convenient to automatically boost the excessively low voltage within a certain range on the user side to the rated voltage of 220V±5%, which makes the user voltage too low and causes household appliances to not work normally. Therefore, we need to propose a rural power grid low voltage boosting device and a voltage boosting method to solve the above-mentioned problems. Summary of the invention

[0006] In view of the above problems, the present invention provides a low voltage boosting device for rural power grid, comprising a voltage boosting device body connected to a user meter box, the voltage boosting device body being installed on a power pole within 10 meters of the user or on the front end of the user meter box, and the voltage boosting device body being connected to a user meter box by a 6mm diameter 2 The above wires are connected to the rural grid transformer;

[0007] The voltage boosting device body includes a low voltage controller that can be controlled by a single chip microcomputer, an AC contactor, a miniature circuit breaker connected to the rural power grid circuit, and a compensation capacitor with a graded switching function. One end of the miniature circuit breaker is connected to the live wire and the neutral wire of the rural power grid transformer, and the other end of the miniature circuit breaker is connected to the low voltage controller. The AC contactor is provided with an A contact and a control contact. One end of the A contact is respectively connected to the input end of the low voltage controller, and the other end of the A contact is connected to the neutral wire of the rural power grid transformer. One end of the control contact is connected to the compensation capacitor.

[0008] The load of the split compensation capacitor is reduced when the user's power voltage is restored. When the user's power voltage returns to normal, the capacitance compensated by the split compensation capacitor will automatically exit step by step.

[0009] Furthermore, the voltage boosting device body is provided with multiple groups, each of which is connected to a user metering box of a user, and each of which is connected to the rural power grid transformer.

[0010] Furthermore, the low voltage controller is configured as a programmable time controller, which monitors and controls the low voltage condition through the processes of power input and signal processing, voltage monitoring and comparison, timing and delay functions, and action execution and control output.

[0011] Furthermore, the AC contactor is configured as three single-phase vacuum contactors, one end of the A contacts of the three single-phase vacuum contactors are connected in parallel to the input end of the low voltage controller, the other end of the A contacts of the three single-phase vacuum contactors are connected to the neutral line of the rural power grid transformer, and one end of the neutral line of the rural power grid transformer is connected to the neutral line pin of the compensation capacitor, one end of the control contacts of the three single-phase vacuum contactors are connected in parallel to the compensation capacitor, and the other end of the control contacts of the three single-phase vacuum contactors are connected to the live wire of the rural power grid transformer.

[0012] Furthermore, the rural power grid transformer is configured as a single-phase transformer for single-phase line voltage transformation, and the wires connecting the rural power grid transformer and the voltage boosting device body are configured as copper wires or aluminum wires.

[0013] Furthermore, the miniature circuit breaker is configured as a 2P air switch for connection to the rural power transformer, and the voltage boosting device body is suitable for connection to single-phase line users. There are the following two situations during connection:

[0014] 1) When there is a utility pole within 10 meters of the user, install the voltage booster on the utility pole, and connect the L and N wires from the utility pole to one end of the miniature circuit breaker;

[0015] 2) When there is no electric pole within 10 meters of the user, the voltage booster device body is installed at the front end of the user's meter box, and the L line and N line are drawn from the electric pole and connected to one end of the miniature circuit breaker.

[0016] Furthermore, there are two AC contactors, and the compensation capacitor includes a capacitor C1 and a capacitor C2 which are arranged in parallel. One end of the control contacts of the two AC contactors is respectively connected to the capacitor C1 and the capacitor C2, and the A contacts of the two AC contactors are both connected to the input end of the low-voltage controller.

[0017] Furthermore, the miniature circuit breaker is configured as a 4P air switch, the rural power grid transformer is configured as a three-phase transformer connected to one end of the miniature circuit breaker, and the other end of the miniature circuit breaker is connected to the other end of the control contacts of the two AC contactors.

[0018] Furthermore, when the miniature circuit breaker is connected to the rural power transformer and the user meter box, there are the following two situations:

[0019] A1. If there is a utility pole within 10 meters of the user, install the voltage booster on the utility pole, and draw three live wires and one neutral wire from the utility pole to connect them to the four connection ports on the upper end of the miniature circuit breaker respectively;

[0020] A2. When there is no electric pole within 10 meters of the user, install the voltage booster device at the front end of the user's meter box, and draw three live wires and one neutral wire from the electric pole and connect them to the four connection ports at the upper end of the miniature circuit breaker respectively.

[0021] Based on the above-described low-voltage boosting device for a rural power grid, the present invention further provides a low-voltage boosting method for a rural power grid, comprising the following steps:

[0022] S1. Install multiple voltage booster bodies on electric poles within 10 meters of multiple end users or at the front end of user meter boxes;

[0023] S2, connect the main bodies of multiple voltage boosting devices with the user's metering box and the rural power grid transformer respectively using electric wires from the live wire and the neutral wire on the electric pole, and pre-set the low voltage threshold through the low voltage controller;

[0024] S3, continuously monitor the voltage level of the rural power grid through the low voltage controller. When it is detected that the voltage is lower than the preset low voltage threshold, the low voltage controller will determine that the voltage needs to be increased and send a switching control signal;

[0025] S4, the AC contactor takes action after receiving the switching control signal, connects the split compensation capacitor to the circuit, and the control contacts of the AC contactor are closed to allow current to pass through the split compensation capacitor;

[0026] S5. The sub-compensation capacitors are used in different numbers to provide different capacitive reactances according to the needs. The capacitive reactances provided by the sub-compensation capacitors resonate with the inductive loads of the rural power system to improve the supply voltage of the end users in stages.

[0027] S6. When the voltage exceeds the user's power supply rated value, the miniature circuit breaker disconnects the circuit to cut off the boost of the user's power supply voltage by the compensation capacitor.

[0028] The beneficial effects of the present invention are:

[0029] 1. The present invention uses a voltage boosting device body which is mainly composed of a low voltage controller, an AC contactor, a miniature circuit breaker and a compensation capacitor. The voltage boosting device body is small in size and is installed on a utility pole within 10 meters of the user or at the front end of the user's metering box, so as to utilize the compensation characteristics and capacitance rise effect of the compensation capacitor to stabilize the user's power voltage and ensure the normal use of the user's household appliances.

[0030] 2. The present invention reduces the load when the user's power voltage is restored by setting up the separate compensation capacitor. When the user's power voltage returns to normal, the capacitance compensated by the separate compensation capacitor will automatically exit step by step to ensure that the working voltage is prevented from rising and unnecessary compensation is prevented.

[0031] 3. The present invention realizes remote control and automatic control of the user's power voltage through the cooperation of a low-voltage controller that can be controlled by a single-chip microcomputer and an AC contactor. It can use 4G / 5G communication for networking control, remotely obtain the user's voltage conditions, and increase the end-user voltage by 0-20V or even above 30V through the compensation characteristics and capacity rise effect of the compensation capacitor, thereby effectively improving the user's low power voltage.

[0032] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic diagram of a main circuit of a voltage boosting device according to Embodiment 1 of the present invention is shown;

[0035] Figure 2 A schematic diagram of the installation of the voltage boosting device according to Embodiment 1 of the present invention is shown;

[0036] Figure 3 A schematic diagram of a main circuit of a voltage boosting device according to Embodiment 2 of the present invention is shown;

[0037] Figure 4 A schematic diagram of the installation of the voltage boosting device according to Embodiment 2 of the present invention is shown;

[0038] Figure 5 A schematic diagram of installing multiple voltage boosting device bodies according to an embodiment of the present invention is shown.

[0039] In the figure: 1. User meter box; 2. Voltage booster device body; 3. Rural power grid transformer. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] An embodiment of the present invention provides a rural power grid low-voltage boosting device, comprising a voltage boosting device body 2 connected to a user meter box 1, wherein the voltage boosting device body 2 is installed on a utility pole within 10 meters from the user or at the front end of the user meter box 1, and the voltage boosting device body 2 is connected to a rural power grid transformer 3 via an electric wire with a diameter of 6 mm2 or more; the voltage boosting device body 2 is installed close to the user so as to utilize the compensation characteristics and capacitance rise effect of the separate compensation capacitor to stabilize the user's power voltage, so as to ensure the normal use of the user's household appliances.

[0043] The voltage boosting device body 2 includes a low voltage controller that can be controlled by a single-chip microcomputer, an AC contactor, a miniature circuit breaker connected to the rural power grid circuit, and a compensation capacitor with a graded switching function. One end of the miniature circuit breaker is connected to the live wire and the neutral wire of the rural power grid transformer 3, and the other end of the miniature circuit breaker is connected to the low voltage controller. The AC contactor is provided with an A contact and a control contact. One end of the A contact is respectively connected to the input end of the low voltage controller, and the other end of the A contact is connected to the neutral wire of the rural power grid transformer 3. One end of the control contact is connected to the compensation capacitor. The compensation capacitor is connected to the low voltage controller through the AC contactor. The AC contactor can realize remote control and automatic control of the user's power voltage. 4G / 5G communication can be used for networking control to remotely obtain the user's voltage situation. Through the compensation characteristics and capacitance rise effect of the compensation capacitor, the end user voltage is increased by 0-20V, or even above 30V, effectively improving the low voltage of user electricity.

[0044] The load of the separate compensation capacitor is reduced when the user's power voltage is restored. When the user's power voltage returns to normal, the capacitance compensated by the separate compensation capacitor will automatically exit step by step, ensuring to prevent the working voltage from rising and unnecessary compensation.

[0045] The AC contactor is set as three single-phase vacuum contactors, one end of the A contact of the three single-phase vacuum contactors is connected in parallel to the input end of the low voltage controller, the other end of the A contact of the three single-phase vacuum contactors is connected to the zero line of the rural power transformer 3, and one end of the zero line of the rural power transformer 3 is connected to the zero line foot of the sub-compensation capacitor, one end of the control contact of the three single-phase vacuum contactors is connected in parallel to the sub-compensation capacitor, and the other end of the control contact of the three single-phase vacuum contactors is connected to the live wire of the rural power transformer 3. By connecting the three single-phase vacuum contactors in parallel to the low voltage controller, the load capacity of the entire rural power system is increased. When one or two of the single-phase vacuum contactors fail, the other single-phase vacuum contactors can still work normally, thereby ensuring the continuity and reliability of the system. The parallel connection of the three single-phase vacuum contactors and the sub-compensation capacitor can achieve a precise graded switching effect, making the sub-compensation capacitor switch more accurate, and preventing overvoltage caused by excessive input capacitors. It can independently and quickly disconnect or connect the circuit, so that it can flexibly adapt to load changes and fault conditions to improve the response speed of the system.

[0046] The rural power grid transformer 3 is configured as a single-phase transformer for single-phase line transformation. The wires connecting the rural power grid transformer 3 and the voltage boosting device body 2 are configured as copper wires or aluminum wires. The miniature circuit breaker is configured as a 2P air switch for connection to the rural power grid transformer 3. The 2P air switch has two main contacts, one for connecting the neutral wire and the other for connecting the live wire. It can control two lines at the same time. This 2P air switch is relatively small in size, easy to install, and has the function of leakage protection, which is convenient for modular setting and later maintenance.

[0047] The voltage boosting device body 2 is suitable for use in connection with single-phase line users, such as Figure 2 As shown, there are two situations when connecting:

[0048] 1) When there is an electric pole within 10 meters of the user, the voltage booster device body 2 is installed on the electric pole, and the L line and N line are connected to one end of the miniature circuit breaker from the electric pole;

[0049] 2) When there is no electric pole within 10 meters of the user, the voltage booster body 2 is installed at the front end of the user meter box 1, and the L line and N line are drawn from the electric pole and connected to one end of the miniature circuit breaker;

[0050] By installing the voltage boosting device body 2 at a position close to the user load, it is convenient to automatically perform capacitance compensation according to the degree of voltage reduction of the user.

[0051] The voltage boosting device body 2 is provided with multiple groups, each of which is connected to a user metering box 1 of a user, and each of which is connected to the rural power grid transformer 3, so that multiple voltage boosting device bodies 2 are installed in a distributed manner, and each voltage boosting device body 2 is close to the end user, so as to centralize the voltage boosting device bodies 2 at multiple locations to realize centralized management of multiple voltage boosting device bodies 2.

[0052] The low voltage controller is configured as a programmable time controller. Figure 1 The low and medium voltage controller is represented by PTKDOY, the three single-phase vacuum contactors are represented by KM1, KM2 and KM3 respectively, the miniature circuit breaker is represented by QF1, and the compensation capacitor is represented by C. The time controller monitors and controls the low voltage condition through the process of power input and signal processing, voltage monitoring and comparison, timing and delay functions, action execution and control output. At the same time, through the programmable function, the user can flexibly configure the parameters and logic of the controller according to actual needs. It is easy to install and does not require on-site parameter configuration. It is plug-and-play. It adopts intelligent single-chip control, which is reliable, stable, and accurate logic program. It coordinates switching through voltage control, can be intelligently grouped, and can control time while grouping.

[0053] Among them, power input and signal processing: the low voltage controller receives power input from the rural power system and processes the input signal through the internal circuit. The input signal may include power system parameters such as voltage, current, and frequency.

[0054] Voltage monitoring and comparison: The low voltage controller has a voltage monitoring circuit inside to monitor the input voltage level in real time. At the same time, a reference voltage value or voltage range is set inside the controller. When the monitored voltage is lower than or exceeds the set reference value, the controller will trigger the corresponding action.

[0055] Timing and delay function: Low voltage controllers usually have timing and delay functions, which are used to delay the execution of corresponding actions after the voltage is lower than the reference value. This delay function can avoid false actions caused by instantaneous voltage fluctuations.

[0056] Action execution and control output: When the voltage is detected to be lower than the reference value and after the set delay time, the low voltage controller will execute the preset action, such as issuing an alarm signal, cutting off the load, starting the backup power supply, etc. The control output part is responsible for converting the executed action into the corresponding control signal or operation instruction.

[0057] Programmable function: Low voltage controllers usually have programmable functions, and users can set the parameters and action logic of the controller through programming. For example, different voltage thresholds, delay times, action types, etc. can be set to meet specific application requirements.

[0058] The miniature circuit breaker includes an on-off contact, a magnetic trip coil, a thermal trip bimetallic strip and an arc extinguishing unit, and the on-off contact, the magnetic trip coil, the thermal trip bimetallic strip and the arc extinguishing unit work together to protect the circuit from overcurrent, overload and short circuit. When an abnormal situation occurs in the circuit, the miniature circuit breaker can quickly cut off the circuit, thereby protecting electrical appliances and ensuring personal safety.

[0059] Among them, the on-off contact: The on-off contact is closed under normal circumstances, allowing current to pass. When an abnormal situation occurs in the circuit, the contact will quickly open and cut off the current.

[0060] Magnetic trip coil: When a short-circuit current appears in the circuit, the magnetic trip coil will be affected by the magnetic field generated by the short-circuit current, triggering the trip mechanism to disconnect the on-off contacts. The magnetic trip method can instantly disconnect the circuit and play a role in short-circuit protection.

[0061] Thermal trip bimetallic strip: Thermal tripping uses the deformation of the bimetallic strip after being heated to trigger the tripping mechanism. When an overload current appears in the circuit, the bimetallic strip will bend due to the heat, thereby triggering the tripping mechanism and disconnecting the on-off contacts, which is used for long-delay overload protection.

[0062] Based on the above-described low-voltage boosting device for a rural power grid, the present invention further provides a low-voltage boosting method for a rural power grid, comprising the following steps:

[0063] S1, installing multiple voltage boosting device bodies 2 on utility poles within 10 meters of multiple end users or at the front end of user meter boxes 1;

[0064] S2, connect multiple voltage boosting device bodies 2 with user metering boxes 1 and rural grid transformers 3 respectively using live wires and neutral wires from electric poles, and preset low voltage thresholds through low voltage controllers;

[0065] S3, continuously monitor the voltage level of the rural power grid through the low voltage controller. When it is detected that the voltage is lower than the preset low voltage threshold, the low voltage controller will determine that the voltage needs to be increased and send a switching control signal;

[0066] S4, the AC contactor takes action after receiving the switching control signal, connects the split compensation capacitor to the circuit, and the control contacts of the AC contactor are closed to allow current to pass through the split compensation capacitor;

[0067] S5. The sub-compensation capacitors are used in different numbers to provide different capacitive reactances according to the needs. The capacitive reactances provided by the sub-compensation capacitors resonate with the inductive loads of the rural power system to improve the supply voltage of the end users in stages.

[0068] S6. When the voltage exceeds the user's power supply rated value, the miniature circuit breaker disconnects the circuit to cut off the boost of the user's power supply voltage by the compensation capacitor.

[0069] Example 2

[0070] The similarities are not repeated here. The difference from Example 1 is that two AC contactors are provided, and the split compensation capacitor includes a capacitor C1 and a capacitor C2 which are arranged in parallel. One end of the control contacts of the two AC contactors is connected to the capacitor C1 and the capacitor C2 respectively, and the A contacts of the two AC contactors are connected to the input end of the low voltage controller (such as Figure 3 The medium and low voltage controller is represented by PTK, the two AC contactors are represented by KM1 and KM2 respectively, and the miniature circuit breaker is represented by QF1), so that the voltage boosting device body 2 is suitable for use by three-phase line users.

[0071] The miniature circuit breaker is configured as a 4P air switch, the rural power transformer 3 is configured as a three-phase electric transformer connected to one end of the miniature circuit breaker, and the other end of the miniature circuit breaker is connected to the other end of the control contacts of the two AC contactors. The 4P air switch has four connection ports, can control four circuits at the same time, and provide protection when an abnormality occurs in the circuit, ensuring the normal operation and safety of the user's household appliances.

[0072] When the miniature circuit breaker is connected to the rural grid transformer 3 and the user meter box 1, Figure 4 As shown, there are two situations:

[0073] A1. When there is an electric pole within 10 meters of the user, the voltage booster body 2 is installed on the electric pole, and three live wires (i.e. A, B, C) and a neutral wire N are drawn from the electric pole and connected to the four connection ports at the upper end of the miniature circuit breaker respectively;

[0074] A2. When there is no electric pole within 10 meters near the user, the voltage boosting device body 2 is installed at the front end of the user's metering box 1, and three live wires (i.e. A, B, C) and a neutral wire N are drawn from the electric pole and connected to the four connection ports on the upper end of the miniature circuit breaker respectively; by installing the voltage boosting device body 2 at a position close to the user's load, it is convenient to automatically perform capacitance compensation according to the degree of voltage reduction of the user.

[0075] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low voltage boosting device for a rural power grid, characterized in that: The invention comprises a voltage boosting device body (2) connected to a user meter box (1), the voltage boosting device body (2) being installed on a power pole within 10 meters of the user or at the front end of the user meter box (1), and the voltage boosting device body (2) being connected to a rural power transformer (3) via an electric wire with a diameter of 6 mm2 or more; The voltage boosting device body (2) comprises a low voltage controller that can be controlled by a single chip microcomputer, an AC contactor, a miniature circuit breaker connected to the rural power grid circuit, and a compensation capacitor with a graded switching function, one end of the miniature circuit breaker is connected to the live wire and the neutral wire of the rural power grid transformer (3), the other end of the miniature circuit breaker is connected to the low voltage controller, the AC contactor is provided with an A contact and a control contact, one end of the A contact is respectively connected to the input end of the low voltage controller, the other end of the A contact is connected to the neutral wire of the rural power grid transformer (3), and one end of the control contact is connected to the compensation capacitor; The load of the split compensation capacitor is reduced when the user's power voltage is restored. When the user's power voltage returns to normal, the capacitance compensated by the split compensation capacitor will automatically exit step by step.

2. The low voltage boosting device for a rural power grid according to claim 1, characterized in that: The voltage boosting device body (2) is provided in multiple groups, each of which is connected to a user metering box (1) of a user, and each of which is connected to a rural power grid transformer (3).

3. The low voltage boosting device for a rural power grid according to claim 2, characterized in that: The low voltage controller is configured as a programmable time controller, which monitors and controls the low voltage condition through the processes of power input and signal processing, voltage monitoring and comparison, timing and delay functions, and action execution and control output.

4. A low voltage boosting device for a rural power grid according to claim 3, characterized in that: The AC contactor is configured as three single-phase vacuum contactors, one end of the A contacts of the three single-phase vacuum contactors is connected in parallel to the input end of the low voltage controller, the other end of the A contacts of the three single-phase vacuum contactors is connected to the neutral line of the rural power transformer (3), and one end of the neutral line of the rural power transformer (3) is connected to the neutral line pin of the compensation capacitor, one end of the control contacts of the three single-phase vacuum contactors is connected in parallel to the compensation capacitor, and the other end of the control contacts of the three single-phase vacuum contactors is connected to the live line of the rural power transformer (3).

5. The low voltage boosting device for rural power grid according to claim 4, characterized in that: The rural power transformer (3) is configured as a single-phase transformer used for single-phase line voltage transformation, and the wires connecting the rural power transformer (3) and the voltage boosting device body (2) are configured as copper wires or aluminum wires.

6. A low voltage boosting device for a rural power grid according to claim 5, characterized in that: The miniature circuit breaker is configured as a 2P air switch for connection to a rural power transformer (3), and the voltage boosting device body (2) is suitable for connection to single-phase line users. During connection, there are the following two situations: 1) When there is an electric pole within 10 meters of the user, the voltage booster device body (2) is installed on the electric pole, and the L line and the N line are connected to one end of the miniature circuit breaker from the electric pole; 2) When there is no electric pole within 10 meters of the user, the voltage boosting device body (2) is installed at the front end of the user meter box (1), and the L line and the N line are drawn from the electric pole and connected to one end of the miniature circuit breaker.

7. The low voltage boosting device for a rural power grid according to claim 3, characterized in that: There are two AC contactors, and the compensation capacitor includes a capacitor C1 and a capacitor C2 which are arranged in parallel. One end of the control contacts of the two AC contactors is respectively connected to the capacitor C1 and the capacitor C2, and the A contacts of the two AC contactors are both connected to the input end of the low-voltage controller.

8. The low voltage boosting device for the rural power grid according to claim 7, characterized in that: The miniature circuit breaker is configured as a 4P air switch, the rural power grid transformer (3) is configured as a three-phase transformer connected to one end of the miniature circuit breaker, and the other end of the miniature circuit breaker is connected to the other end of the control contacts of the two AC contactors.

9. The low voltage boosting device for the rural power grid according to claim 8, characterized in that: When the miniature circuit breaker is connected to the rural power transformer (3) and the user meter box (1), the following two situations exist: A1. When there is an electric pole within 10 meters of the user, the voltage booster body (2) is installed on the electric pole, and three live wires and one neutral wire are drawn from the electric pole and connected to the four connection ports at the upper end of the miniature circuit breaker respectively; A2. When there is no electric pole within 10 meters of the user, the voltage boosting device body (2) is installed at the front end of the user meter box (1), and three live wires and one neutral wire are drawn from the electric pole and connected to the four connection ports at the upper end of the miniature circuit breaker respectively.

10. A method for increasing low voltage in a rural power grid, based on a device for increasing low voltage in a rural power grid according to any one of claims 1 to 9, characterized in that: The steps include: S1, installing a plurality of voltage boosting device bodies (2) on electric poles within 10 meters of a plurality of end users or at the front end of a user meter box (1); S2, using live wires and neutral wires from electric poles to connect multiple voltage boosting device bodies (2) to user meter boxes (1) and rural power transformers (3) respectively using electric wires, and presetting low voltage thresholds through low voltage controllers; S3, continuously monitor the voltage level of the rural power grid through the low voltage controller. When it is detected that the voltage is lower than the preset low voltage threshold, the low voltage controller will determine that the voltage needs to be increased and send a switching control signal; S4, the AC contactor takes action after receiving the switching control signal, connects the split compensation capacitor to the circuit, and the control contacts of the AC contactor are closed to allow current to pass through the split compensation capacitor; S5. The sub-compensation capacitors are used in different numbers to provide different capacitive reactances according to the needs. The capacitive reactances provided by the sub-compensation capacitors resonate with the inductive loads of the rural power system to improve the supply voltage of the end users in stages. S6. When the voltage exceeds the user's power supply rated value, the miniature circuit breaker disconnects the circuit to cut off the boost of the user's power supply voltage by the compensation capacitor.

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