Low-cost fault control device and method based on low-power active module integration and adaptive control

Abstract

The present invention discloses a low-cost fault control device based on low-power active module integration and adaptive control, including: one end of the arc suppression coil is connected to the neutral point of the power grid; the mechanical switch module is connected to the main trunk of the arc suppression coil at preset intervals through a preset number of taps to form a preset number of gears; the gears include a first switch and a second switch, which are respectively connected to the upper branch and the lower branch of the mechanical switch module; the mechanical switch module is connected to the balance winding through a bias transformer and then grounded. The DC side capacitor is connected to the primary winding of the bias transformer through a first voltage type converter, and is connected to the primary winding of the output transformer through a second voltage type converter; the same-name end of the secondary winding of the output transformer is connected to the neutral point of the power grid, and the opposite-name end of the secondary winding is grounded; the positive and negative poles of the rectifier are respectively connected to the positive and negative poles of the DC side capacitor; the rectifier is also connected to the power grid. The present invention also discloses a low-cost fault control method based on low-power active module integration and adaptive control.

Description

Technical Field

[0001] The present invention relates to the technical field of single-phase grounding fault control in a distribution network, and in particular to a low-cost fault control device and method based on low-power active module integration and adaptive control. Background Art

[0002] During the operation of the distribution network, there are a large number of single-phase grounding faults caused by complex reasons such as lightning strikes, short-term contact between branches and conductors, insulator contamination and breakdown, and cable degradation. Small current grounding methods, especially resonant grounding methods, have the advantages of compensating for single-phase grounding fault currents and improving power supply reliability. In the resonant grounding method, the arc suppression coil over-compensates the capacitive current to the ground, which can effectively suppress the residual current at the fault point to the self-extinguishing range. When the current passes through zero and the arc is extinguished, the arc suppression coil can reduce the recovery speed of the fault phase voltage, thereby significantly reducing the risk of arc reignition and achieving effective control of single-phase grounding faults.

[0003] The turn-adjusting arc-suppression coil has been widely used in distribution networks due to its low cost and clear operating principle. With the continuous expansion of distribution networks in cities and industrial and mining enterprises, the amplitude of the active component in the single-phase ground fault current of the distribution network has increased significantly. The traditional turn-adjusting arc-suppression coil can only generate inductive current to compensate for the power frequency reactive component in the ground fault current. Due to the characteristics of the components, it cannot compensate for the active component in the ground fault current, and an arc will be generated during the turn-adjusting process, which seriously affects the effect of the arc extinguishing device and the reliability of the device itself. In order to improve the reliability and response speed of the arc extinguishing system, relevant scholars have made in-depth research on hybrid on-load tap changers by taking advantage of the flexible control of power electronic switches. The hybrid on-load tap changer suppresses the arc during the switching process of the tap changer, thereby improving the life of the mechanical contact. However, the hybrid on-load tap changer can still only compensate for the reactive component of the single-phase ground fault, and the compensation of the active component in the ground fault current needs further research and improvement.

[0004] Therefore, a new technical solution is urgently needed to solve the technical problem of how to compensate for the composite components of reactive and active power in the single-phase grounding fault current and achieve adaptive suppression of the turn-to-turn arc. Summary of the invention

[0005] The present invention provides a low-cost fault control device and method based on low-power active module integration and adaptive control, which is used to solve the technical problem of how to compensate for the composite components of reactive and active power in single-phase grounding fault current and achieve adaptive suppression of turn-to-turn arc.

[0006] To achieve the above-mentioned objectives, the present invention provides a low-cost fault control device based on low-power active module integration and adaptive control, including a dry arc suppression coil, a bias transformer, a balancing winding, a first voltage-type converter, a rectifier, a DC side capacitor, a mechanical switch module and a low-power active module; the low-power active module includes an output transformer and a second voltage-type converter.

[0007] One end of the dry arc suppression coil is connected to the neutral point of the power grid; the mechanical switch module is connected to the trunk of the dry arc suppression coil at preset intervals through a preset number of taps to form a preset number of gears; the gears include a first switch and a second switch; the first switch and the second switch are respectively connected to the upper branch and the lower branch of the mechanical switch module; the upper branch and the lower branch are respectively connected to the same-name end of the first secondary winding and the opposite-name end of the second secondary winding of the bias transformer; the bias transformer is connected to the balancing winding through the opposite-name end of the first secondary winding and the same-name end of the second secondary winding and then grounded.

[0008] The DC side capacitor is connected to the primary winding of the bias transformer through a first voltage type converter, and is connected to the primary winding of the output transformer through a second voltage type converter; the same-name end of the secondary winding of the output transformer is connected to the neutral point of the power grid, and the opposite-name end of the secondary winding of the output transformer is grounded; the positive and negative poles of the rectifier are respectively connected to the positive and negative poles of the DC side capacitor; the rectifier is also connected to the power grid through the power grid connection terminal.

[0009] Preferably, the first voltage-type converter and the second voltage-type converter have the same structure, both including a fully controlled device S 1 、 S 2 、S 3 and S 4 , each fully controlled device includes a freewheeling diode connected in parallel therewith; wherein, S 1's emitter is connected to S 3's collector and serves as the input of the voltage-type converter. S 2's emitter is connected to S The collector of 4 serves as the output terminal of the voltage source converter; S 1 and S 2 are connected to each other and serve as the first terminal of the voltage source converter. S 3 and S The emitters of 4 are connected to each other and serve as the second terminal of the voltage-type converter.

[0010] Preferably, the DC side capacitor is connected to the primary winding of the bias transformer through a first voltage type converter, and is connected to the primary winding of the output transformer through a second voltage type converter, including:

[0011] The positive and negative electrodes of the DC side capacitor are respectively connected to the first terminal and the second terminal of the first voltage type converter, and the input end and the output end of the first voltage type converter are respectively connected to the opposite end and the same end of the primary winding of the bias transformer.

[0012] The positive and negative electrodes of the DC side capacitor are also connected to the first terminal and the second terminal of the second voltage type converter respectively, and the input end and the output end of the second voltage type converter are connected to the opposite end and the same end of the primary winding of the output transformer respectively.

[0013] Preferably, the rectifier comprises a diode D 1. D 2. D 3. D 4. D 5 and D 6.

[0014] in, D 2. D 4 and D 6 are connected to the positive pole D 1. D 3 and D 5 and serves as the negative pole of the grid connection terminal.

[0015] D 1. D 3 and D The positive electrode of 5 is used as the positive electrode of the rectifier; D 2. D 4 and D The negative electrode of 6 serves as the negative electrode of the rectifier.

[0016] Preferably, the bias transformer is connected to the balance winding through the opposite-name end of the first secondary winding and the same-name end of the second secondary winding and then grounded, comprising:

[0017] The bias transformer is connected to the first winding first end of the balancing winding through the opposite-name end of the first secondary winding.

[0018] The bias transformer is connected to the second winding second end of the balancing winding via the second secondary winding like-name end.

[0019] The second end of the first winding of the balancing winding is connected to the first end of the second winding of the balancing winding and then grounded.

[0020] The present invention also provides a low-cost fault control method based on low-power active module integration and adaptive control. The device based on the present invention includes:

[0021] The power grid is monitored in real time. When a single-phase grounding fault occurs, the inductance required to compensate the reactive component and the active current required to compensate the active component are calculated to obtain the compensation inductance value and the compensation current value respectively.

[0022] According to the compensation inductance value, SPWM modulation wave control is performed through the first voltage-type converter, and the arc extinguishing current of the upper branch and the lower branch are controlled to be in the first state in an arbitrary order; the first state includes controlling the arc extinguishing current to be zero, and restoring the arc extinguishing current to a normal state after a preset time; when the arc extinguishing current of the upper branch is zero, the first switch switching between the current gear and the target gear is completed, and when the arc extinguishing current of the lower branch is zero, the second switch switching between the current gear and the target gear is completed; before any switch switching between the current gear and the target gear and after all switch switching is completed, the upper branch and the lower branch are controlled to evenly share the arc extinguishing current; after completing the switching between the gears, the effective inductance of the dry arc extinguishing coil is equal to the compensation inductance value, and the reactive component in the single-phase grounding fault is compensated by the dry arc extinguishing coil.

[0023] According to the compensation current value, SPWM modulation wave control is performed through the second voltage-type converter, so that the output current of the second voltage-type converter is equal to the compensation current value, and the active component compensation in the single-phase grounding fault is completed; the regulation of the single-phase grounding fault is realized.

[0024] Preferably, performing SPWM modulation wave control through the first voltage source converter according to the compensation inductance value includes:

[0025] The compensation inductance value is converted into a preset value to obtain a first SPWM modulation wave; the first SPWM modulation wave is input into the first voltage type converter to realize the control of the first voltage type converter.

[0026] Preferably, performing SPWM modulation wave control through the second voltage source converter according to the compensation current value includes:

[0027] The compensation current value is converted in a preset manner to obtain a second SPWM modulation wave; the second SPWM modulation wave is input into the second voltage type converter to realize control of the second voltage type converter.

[0028] Preferably, the inductance required for calculating the reactive component compensation can be expressed by the following relationship:

[0029] in, Indicates the compensation inductance value; Indicates the capacitance of the A phase line of the power grid; Indicates the capacitance of the phase B line of the power grid; Indicates the capacitance of the phase C line of the power grid; .

[0030] Preferably, the active current required for calculating the active component compensation can be expressed by the following relationship:

[0031] in, Indicates the active current required to compensate the active component, according to As a reference value, a compensation current value of the same magnitude is obtained; Indicates the grid A phase voltage; It represents the equivalent conductance of the A phase line of the power grid.

[0032] The present invention has the following beneficial effects:

[0033] The low-cost fault control device based on low-power active module integration and adaptive control of the present invention, by setting a mechanical switch module with dual switches in one gear, enables the device of the present invention to be used for arc-free switching of dual switches between different gears, thereby realizing arc-free reactive power compensation, avoiding the influence of arc generated during the switching process of traditional single switch; by adding a low-power active module, the device of the present invention can be used to compensate for the active component in a single-phase grounding fault through the low-power active module. While the device of the present invention can be used to compensate for the reactive component in a single-phase grounding fault without arc, it realizes compensation for the active component in a single-phase grounding fault, so that the device of the present invention can compensate for the composite components of reactive and active power in the single-phase grounding fault current and realize adaptive suppression of the regulating arc.

[0034] The low-cost fault control method based on low-power active module integration and adaptive control of the present invention is based on the device of the present invention and has the same beneficial effects as the device of the present invention.

[0035] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0037] Figure 1 It is a schematic diagram of the device of the preferred embodiment 1 of the present invention.

[0038] Figure 2 It is a schematic diagram of step 1 of adjusting the device of preferred embodiment 2 of the present invention from N gear to +1 gear.

[0039] Figure 3 It is a schematic diagram of step 2 of adjusting the device of preferred embodiment 2 of the present invention from N gear to +1 gear.

[0040] Figure 4 It is a schematic diagram of step 3 of adjusting the device of preferred embodiment 2 of the present invention from N gear to +1 gear.

[0041] Figure 5It is a schematic diagram of step 4 of adjusting the device of preferred embodiment 2 of the present invention from N gear to +1 gear.

[0042] Figure 6 It is a schematic diagram of step 5 of adjusting the device of preferred embodiment 2 of the present invention from N gear to +1 gear.

[0043] Figure 7 It is a schematic diagram of step six of adjusting the device of preferred embodiment 2 of the present invention from N gear to +1 gear.

[0044] Figure 8 This is a schematic diagram of step seven of adjusting the device of preferred embodiment 2 of the present invention from N gear to +1 gear.

[0045] In the attached picture:

[0046] 100, dry arc suppression coil; 200, bias transformer; 210, first secondary winding; 220, second secondary winding; 230, bias transformer primary winding; 300, balance winding; 310, first winding; 320, second winding; 400, first voltage type converter; 500, rectifier; 600, DC side capacitor; 700, mechanical switch module; 710, second switch; 720, first switch; 800, output transformer; 900, second voltage type converter. DETAILED DESCRIPTION

[0047] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0048] Embodiment 1:

[0049] See also Figure 1 In a preferred embodiment of the present invention, a distribution network single-phase grounding fault control device based on a low-power active module is provided, including a dry arc suppression coil 100, a bias transformer 200, a balancing winding 300, a first voltage-type converter 400, a rectifier 500, a DC side capacitor 600, a mechanical switch module 700 and a low-power active module; the low-power active module includes an output transformer 800 and a second voltage-type converter 900.

[0050] One end of the dry arc extinguishing coil 100 is connected to the neutral point of the power grid; the mechanical switch module 700 is connected to the trunk of the dry arc extinguishing coil 100 at a preset interval through a preset number of taps to form a preset number of gears; the gears include a first switch 720 and a second switch 710; the first switch 720 and the second switch 710 are respectively connected to the upper branch and the lower branch of the mechanical switch module 700; the upper branch and the lower branch are respectively connected to the same-name end of the first secondary winding 210 and the opposite-name end of the second secondary winding 220 of the bias transformer 200; the bias transformer The bias transformer 200 is connected to the balancing winding 300 through the opposite-name end of the first secondary winding 210 and the same-name end of the second secondary winding 220 and then grounded, including: the bias transformer 200 is connected to the first end of the first winding 310 of the balancing winding 300 through the opposite-name end of the first secondary winding 210; the bias transformer 200 is connected to the second end of the second winding 320 of the balancing winding 300 through the same-name end of the second secondary winding 220; the second end of the first winding 310 of the balancing winding 300 is connected to the first end of the second winding 320 of the balancing winding 300 and then grounded.

[0051] The first voltage-type converter 400 and the second voltage-type converter 900 have the same structure, both including a fully controlled device S 1 、 S 2 、S 3 and S 4 , each fully controlled device includes a freewheeling diode connected in parallel therewith; wherein, S 1's emitter is connected to S 3's collector and serves as the input of the voltage-type converter. S 2's emitter is connected to S The collector of 4 serves as the output terminal of the voltage source converter; S 1 and S 2 are connected to each other and serve as the first terminal of the voltage source converter. S 3 and S The emitters of 4 are connected to each other and serve as the second terminal of the voltage-type converter.

[0052] The DC link capacitor 600 is connected to the bias transformer primary winding 230 through the first voltage source converter 400 and is connected to the output transformer primary winding 800 through the second voltage source converter 900, specifically including:

[0053] The positive and negative electrodes of the DC link capacitor 600 are respectively connected to the first terminal and the second terminal of the first voltage source converter 400 , and the input and output ends of the first voltage source converter 400 are respectively connected to the opposite-name end and the same-name end of the primary winding 230 of the bias transformer.

[0054] The positive and negative electrodes of the DC link capacitor 600 are also connected to the first terminal and the second terminal of the second voltage source converter 900 respectively. The input and output ends of the second voltage source converter 900 are connected to the opposite-name end and the same-name end of the primary winding of the output transformer 800 respectively.

[0055] The positive and negative electrodes of the rectifier 500 are respectively connected to the positive and negative electrodes of the DC-side capacitor 600 ; the rectifier 500 is also connected to the grid through the grid connection terminal to provide a DC-side voltage for the DC-side capacitor 600 .

[0056] The rectifier 500 includes a diode D 1. D 2. D 3. D 4. D 5 and D 6.

[0057] in, D 2. D 4 and D 6 are connected to the positive pole D 1. D 3 and D 5 and serves as the negative pole of the grid connection terminal.

[0058] D 1. D 3 and D The positive electrode of 5 serves as the positive electrode of the rectifier 500; D 2. D 4 and D The negative electrode of 6 serves as the negative electrode of the rectifier 500.

[0059] The same-name end of the secondary winding of the output transformer 800 is connected to the neutral point of the power grid, and the opposite-name end of the secondary winding of the output transformer 800 is grounded.

[0060] exist Figure 1 middle, Indicates the phase voltage of the three phases A, B and C on the grid side; Represents the capacitance of the three-phase lines A, B and C, which are used to simulate the power grid part; is the fault transition conductance.

[0061] The distribution network single-phase grounding fault control device based on a low-power active module of the present invention, by setting a mechanical switch module 700 with a dual switch in one gear, enables the device of the present invention to be used for arc-free switching of the dual switches between different gears, thereby realizing arc-free reactive power compensation, and avoiding the influence of arcing generated during the switching process of the traditional single switch; by adding a low-power active module, the device of the present invention can be used to compensate for the active component in the single-phase grounding fault through the low-power active module. While the device of the present invention can be used to compensate for the reactive component in the single-phase grounding fault without arcing, it realizes compensation for the active component in the single-phase grounding fault, so that the device of the present invention can compensate for the composite components of reactive and active power in the single-phase grounding fault current and realize adaptive suppression of the regulating arc.

[0062] Embodiment 2:

[0063] In a preferred embodiment of the present invention, a method for controlling single-phase grounding fault in a distribution network based on a low-power active module is provided. The device according to the present invention comprises:

[0064] A1. Carry out monitoring and related calculations:

[0065] The power grid is monitored in real time. When a single-phase grounding fault occurs, the inductance required to compensate the reactive component and the active current required to compensate the active component are calculated to obtain the compensation inductance value and the compensation current value respectively.

[0066] In a preferred embodiment of the present invention, the inductance required for calculating the reactive component compensation can be expressed by the following relationship:

[0067] in, Indicates the compensation inductance value; Indicates the capacitance of the A phase line of the power grid; Indicates the capacitance of the phase B line of the power grid; Indicates the capacitance of the phase C line of the power grid; .

[0068] In a preferred embodiment of the present invention, the magnitude of the active current required to calculate the active component for compensation can be expressed by the following relationship:

[0069] in, Indicates the active current required to compensate the active component, according to As a reference value, a compensation current value of the same magnitude is obtained; Indicates the grid A phase voltage; It represents the equivalent conductance of the A phase line of the power grid.

[0070] A2. Compensation of reactive components:

[0071] According to the compensation inductance value, SPWM modulation wave control is performed through the first voltage-type converter 400, and the arc extinguishing current of the upper branch and the lower branch are controlled to be in the first state in an arbitrary order; the first state includes controlling the arc extinguishing current to be zero, and restoring the arc extinguishing current to a normal state after a preset time; when the arc extinguishing current of the upper branch is zero, the first switch 720 is switched between the current gear and the target gear, and when the arc extinguishing current of the lower branch is zero, the second switch 710 is switched between the current gear and the target gear; before any switch is switched between the current gear and the target gear and after all switch switches are completed, the upper branch and the lower branch are controlled to evenly share the arc extinguishing current; after completing the switching between the gears, the effective inductance of the dry arc extinguishing coil 100 is equal to the compensation inductance value, and the reactive component in the single-phase grounding fault is compensated by the dry arc extinguishing coil 100.

[0072] In a preferred embodiment of the present invention, controlling the arc extinguishing current of the upper branch and the lower branch to the first state in an arbitrary order includes: sequentially controlling the arc extinguishing current of the upper branch and the lower branch to the first state or sequentially controlling the arc extinguishing current of the lower branch and the upper branch to the first state.

[0073] In a preferred embodiment of the present invention, the switch is first controlled to switch the corresponding branch current to 0, and then the switch is switched, ensuring that there is no current during the switch operation, thereby achieving arc-free operation.

[0074] In the preferred embodiment of the present invention, an example is given by adjusting the device of the present invention from N gear to +1 gear:

[0075] Let the upper branch current be , the lower branch current is , then include:

[0076] in, is the arc extinguishing current; is the loop current.

[0077] In a preferred embodiment of the present invention, the loop current It refers to the current in the loop formed between the dry arc suppression coil 100, the mechanical switch module 700, the bias transformer 200 and the balance winding 300.

[0078] In a preferred embodiment of the present invention, when the device is adjusted from gear N to gear +1 and the currents of the lower branch and the upper branch are controlled to be 0 in sequence, steps 1 to 7 are included:

[0079] and A first switch 720 and a second switch 710 respectively represent the N gear; and The first switch 720 and the second switch 710 respectively represent the +1 gear.

[0080] Step 1: See Figure 2 , and All closed, control loop current , upper branch current and lower branch current Not affected by the branch voltage potential difference, the arc extinguishing current is evenly distributed:

[0081]

[0082] Step 2: See Figure 3 , control the lower branch current .

[0083] Step 3: See Figure 4 , and disconnect, Closed, at this time the upper branch current bears all the arc extinguishing current:

[0084]

[0085] Step 4: See Figure 5 , control loop current , upper branch current and lower branch current It is not affected by the voltage potential difference of the branches and the arc extinguishing current is evenly distributed.

[0086] Step 5: See Figure 6 , control the upper branch current .

[0087] Step 6: See Figure 7 , and disconnect, Closed, at this time the upper branch current bears all the arc extinguishing current:

[0088]

[0089] Step 7: See Figure 8 , control loop current , upper branch current and lower branch current The arc extinguishing current is evenly distributed without being affected by the branch voltage potential difference. The device of the present invention is adjusted from the N gear to the +1 gear.

[0090] exist Figures 2 to 8 In the figure, N and +1 in the dotted box indicate the position of the switch connected to the dotted box; and The straight line above or below indicates that the current is 0, and the wavy sign indicates that there is an arc-extinguishing current; Indicates the voltage between different gear switches.

[0091] A3. Compensation of active power components:

[0092] According to the compensation current value, SPWM modulation wave control is performed through the second voltage source converter 900, so that the output current of the second voltage source converter 900 is equal to the compensation current value, the active component compensation in the single-phase grounding fault is completed, and the single-phase grounding fault is controlled.

[0093] In a preferred embodiment of the present invention, performing SPWM modulation wave control through the first voltage source converter 400 according to the compensation inductance value includes:

[0094] The compensation inductance value is converted into a preset value to obtain a first SPWM modulation wave; the first SPWM modulation wave is input into the first voltage source converter 400 to realize control of the first voltage source converter 400.

[0095] In a preferred embodiment of the present invention, performing SPWM modulation wave control through the second voltage source converter 900 according to the compensation current value includes:

[0096] The compensation current value is converted into a preset value to obtain a second SPWM modulated wave; the second SPWM modulated wave is input into the second voltage source converter 900 to realize control of the second voltage source converter 900.

[0097] The distribution network single-phase grounding fault control method based on a low-power active module of the present invention is based on the device of the present invention and has the same beneficial effects as the device of the present invention.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-cost fault control device based on low-power active module integration and adaptive control, characterized in that: The invention comprises a dry arc-extinguishing coil (100), a bias transformer (200), a balancing winding (300), a first voltage-type converter (400), a rectifier (500), a DC-side capacitor (600), a mechanical switch module (700) and a low-power active module; the low-power active module comprises an output transformer (800) and a second voltage-type converter (900); One end of the dry arc extinguishing coil (100) is connected to the neutral point of the power grid; the mechanical switch module (700) is connected to the trunk of the dry arc extinguishing coil (100) at preset intervals through a preset number of taps to form a preset number of gears; the gears include a first switch (720) and a second switch (710); the first switch (720) and the second switch (710) are respectively connected to the upper branch and the lower branch of the mechanical switch module (700); the upper branch and the lower branch are respectively connected to the same-name end of the first secondary winding (210) and the opposite-name end of the second secondary winding (220) of the bias transformer (200); the bias transformer (200) is connected to the balancing winding (300) through the opposite-name end of the first secondary winding (210) and the same-name end of the second secondary winding (220) and then grounded; The DC side capacitor (600) is connected to the bias transformer primary winding (230) through the first voltage type converter (400), and is connected to the output transformer (800) primary winding through the second voltage type converter (900); the same-name end of the secondary winding of the output transformer (800) is connected to the neutral point of the power grid, and the opposite-name end of the secondary winding of the output transformer (800) is grounded; the positive and negative electrodes of the rectifier (500) are respectively connected to the positive and negative electrodes of the DC side capacitor (600); the rectifier (500) is also connected to the power grid through a power grid connection terminal; The first voltage-type converter (400) and the second voltage-type converter (900) have the same structure and both include fully controlled devices. S 1 、S 2 、S 3 and S 4 , each fully controlled device includes a freewheeling diode connected in parallel therewith; in, S 1's emitter is connected to S 3's collector and serves as the input of the voltage-type converter. S 2's emitter is connected to S The collector of 4 serves as the output terminal of the voltage source converter; S 1 and S 2 are connected to each other and serve as the first terminal of the voltage source converter. S 3 and S The emitters of 4 are connected to each other and serve as the second terminal of the voltage source converter; The DC link capacitor (600) is connected to the primary winding (230) of the bias transformer via the first voltage-type converter (400), and is connected to the primary winding of the output transformer (800) via the second voltage-type converter (900), including: The positive and negative electrodes of the DC link capacitor (600) are respectively connected to the first terminal and the second terminal of the first voltage type converter (400); the input end and the output end of the first voltage type converter (400) are respectively connected to the opposite end and the same end of the primary winding (230) of the bias transformer; The positive and negative electrodes of the DC link capacitor (600) are also respectively connected to the first terminal and the second terminal of the second voltage type converter (900), and the input end and the output end of the second voltage type converter (900) are respectively connected to the opposite-name end and the same-name end of the primary winding of the output transformer (800).

2. The low-cost fault control device based on low-power active module integration and adaptive control according to claim 1 is characterized in that: The rectifier (500) includes a diode D 1. D 2. D 3. D 4. D 5 and D 6; in, D 2. D 4 and D 6 are connected to the positive pole D 1. D 3 and D 5's negative pole and serves as a grid connection terminal; D 1. D 3 and D The positive electrode of 5 serves as the positive electrode of the rectifier (500); D 2. D 4 and D The negative electrode of 6 serves as the negative electrode of the rectifier (500).

3. The low-cost fault control device based on low-power active module integration and adaptive control according to claim 2 is characterized in that: The bias transformer (200) is connected to the balancing winding (300) through the opposite-name end of the first secondary winding (210) and the same-name end of the second secondary winding (220) and then grounded, and comprises: The bias transformer (200) is connected to the first end of the first winding (310) of the balancing winding (300) via the opposite-name end of the first secondary winding (210); The bias transformer (200) is connected to the second end of the second winding (320) of the balancing winding (300) via the same-name end of the second secondary winding (220); The second end of the first winding (310) of the balancing winding (300) is connected to the first end of the second winding (320) of the balancing winding (300) and then grounded.

4. A low-cost fault control method based on low-power active module integration and adaptive control, based on the device according to any one of claims 1 to 3, characterized in that: include: The power grid is monitored in real time. When a single-phase grounding fault occurs, the inductance required to compensate the reactive component and the active current required to compensate the active component are calculated to obtain the compensation inductance value and the compensation current value respectively. According to the compensation inductance value, SPWM modulation wave control is performed through the first voltage-type converter (400), and the arc extinguishing currents of the upper branch and the lower branch are controlled to be in a first state in an arbitrary order; the first state includes controlling the arc extinguishing current to be zero, and restoring the arc extinguishing current to a normal state after a preset time; when the arc extinguishing current of the upper branch is zero, the first switch (720) is switched between the current gear and the target gear, and when the arc extinguishing current of the lower branch is zero, the second switch (710) is switched between the current gear and the target gear; before any switch between the current gear and the target gear is switched and after all switch switches are completed, the upper branch and the lower branch are controlled to evenly divide the arc extinguishing current; after the switching between the gears is completed, the effective inductance of the dry arc extinguishing coil (100) is equal to the compensation inductance value, and the reactive component in the single-phase grounding fault is compensated by the dry arc extinguishing coil (100); According to the compensation current value, SPWM modulation wave control is performed through the second voltage type converter (900), so that the output current of the second voltage type converter (900) is equal to the compensation current value, and the active component compensation in the single-phase grounding fault is completed; thus, the regulation of the single-phase grounding fault is realized.

5. The low-cost fault control method based on low-power active module integration and adaptive control according to claim 4 is characterized in that: Performing SPWM modulation wave control through the first voltage-source converter (400) according to the compensation inductance value comprises: The compensation inductance value is converted into a preset value to obtain a first SPWM modulation wave; the first SPWM modulation wave is input into the first voltage type converter (400) to realize control of the first voltage type converter (400).

6. The low-cost fault control method based on low-power active module integration and adaptive control according to claim 5 is characterized in that: Performing SPWM modulation wave control through the second voltage source converter (900) according to the compensation current value comprises: The compensation current value is converted in a preset manner to obtain a second SPWM modulation wave; the second SPWM modulation wave is input into the second voltage type converter (900) to achieve control of the second voltage type converter (900).

7. The low-cost fault control method based on low-power active module integration and adaptive control according to claim 6 is characterized in that: The inductance required to calculate the reactive component compensation can be expressed by the following relationship: in, Indicates the compensation inductance value; Indicates the capacitance of the A phase line of the power grid; Indicates the capacitance of the phase B line of the power grid; Indicates the capacitance of the phase C line of the power grid; .

8. The low-cost fault control method based on low-power active module integration and adaptive control according to claim 7 is characterized in that: The active current required to calculate the active component can be expressed by the following relationship: in, Indicates the active current required to compensate the active component, according to As a reference value, a compensation current value of the same magnitude is obtained; Indicates the grid A phase voltage; It represents the equivalent conductance of the A phase line of the power grid.

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