Ground parameter measurement method and system for neutral point grounded through active arc extinction device power distribution system

Abstract

The application discloses a neutral point active arc extinguishing device grounding power distribution system ground parameter measurement method and system, which is applied to the ground parameter measurement of a single-phase injection transformer with a secondary winding injection power supply or an arc suppression coil grounding generator or a power distribution network, and comprises the following steps: when the power distribution system is normally operated, the size and / or phase of a power supply signal output by a power supply is regulated and controlled, and / or the output impedance of the power supply is regulated and controlled, so that a power frequency signal is injected; the neutral point ground voltage before and after the power supply is regulated and controlled, the primary ground current of the single-phase injection transformer and the ground current of each arc suppression coil are measured; and the ground parameters of the power distribution system are calculated according to the measurement data. The power frequency signal is directly injected by using the active arc extinguishing device, without the need of an external power injection device, so that the measurement signal is large and the anti-interference capability is strong; the power distribution network system structure is not affected, the influence of the neutral point voltage offset in the system on the measurement accuracy is eliminated, the measurement process is safe and reliable, the accuracy is high, and the method can be applied to ground fault detection, arc extinguishing and protection.

Description

Technical Field

[0001] This invention relates to the field of power distribution system ground parameter measurement technology, and in particular to a method and system for measuring ground parameters in a power distribution system with a neutral point grounded by an active arc suppression device. Background Technology

[0002] The emerging active arc suppression technology for power distribution networks in recent years requires precise and rapid real-time measurement technology for ground capacitance and ground leakage conductance as strong support. Currently, the main methods for grounding distribution systems with neutral points via active arc suppression devices include grounding the neutral point through a single-phase injection transformer or by injecting power into the secondary winding of the arc suppression coil. Grounding the neutral point through the secondary winding of a single-phase injection transformer refers to a structure where the single-phase injection transformer and the arc suppression coil are connected in parallel. Grounding the neutral point through the secondary winding of the arc suppression coil refers to a structure where the single-phase injection transformer is placed within the arc suppression coil as its secondary side. Currently used methods for measuring ground parameters in neutral point active arc suppression grounding distribution systems mainly include the bias method, switching resistors or capacitors at the neutral point, and signal injection. The bias method and switching resistors or capacitors at the neutral point measure ground parameters by changing the neutral point displacement voltage. These methods alter the primary system topology and parameters during measurement and require direct contact with primary equipment, making the measurement process cumbersome, inefficient, and posing certain safety risks. The signal injection method injects non-power frequency characteristic signals into the distribution network through the secondary side of the TV (voltage transformer) and measures the feedback signal in real time to realize the measurement of the distribution network's ground parameters. However, the signal injection method is easily affected by the frequency of the injected signal, and is prone to problems such as difficulty in capturing characteristic signals and large errors in measuring ground leakage current. Existing single-frequency measurement methods cannot measure ground conductance and are also unable to adapt to the development of active grounding technology. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method and system for measuring ground parameters in a neutral-point grounded power distribution system with an active arc suppression device, thereby solving the problems of difficulty in capturing characteristic signals and large measurement errors in traditional signal injection methods.

[0004] To achieve the above objectives, the present invention adopts the following technical solution.

[0005] In a first aspect, a method for measuring ground parameters in a neutral-point grounded power distribution system via an active arc suppression device is provided. This method is applied to the measurement of ground parameters in a single-phase injection transformer or arc suppression coil grounded generator or power distribution network where the neutral point is injected with power via a secondary winding. The method includes the following steps:

[0006] During normal operation of the power distribution system, power frequency signal injection is achieved by adjusting the magnitude and / or phase of the power output signal and / or adjusting the power output impedance.

[0007] Measure the neutral point-to-ground voltage before and after the power supply regulation, the primary ground current of the single-phase injection transformer, and the ground current of each arc suppression coil;

[0008] Calculate the ground parameters of the power distribution system based on the measured data.

[0009] Furthermore, the power supply output impedance is adjusted by regulating the power supply output circuit impedance, including the first impedance. Second impedance , where the first impedance The second impedance is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil. It is connected in parallel to both ends of the secondary winding of a single-phase injection transformer or the secondary winding of an arc suppression coil.

[0010] Furthermore, the impedance is adaptively adjusted based on the magnitude of the residual current in the power distribution system. When the residual current in the power distribution system does not exceed the preset setting value, the first impedance... Second impedance Fully engaged; conversely, when the residual current of the power distribution system exceeds the preset setting value, the second impedance... No input, only the first impedance is input. .

[0011] Furthermore, the magnitude of the power output signal is controlled by adjusting the control range of the single-phase injection transformer.

[0012] Furthermore, the phase regulation of the power output signal is achieved by regulating the feedback line voltage switching switch.

[0013] Furthermore, during the power supply regulation process, the neutral point-to-ground voltage range is controlled to be 1% to 15% of the phase voltage of the power distribution system.

[0014] Furthermore, the power distribution system's ground parameters include one or more of the following: ground capacitance, ground leakage conductance, ground capacitance current, detuning degree, ground dielectric loss, and damping rate.

[0015] Furthermore, capacitance to ground Leakage conductivity to ground ground capacitance current The detuning degree ν, the dielectric loss to ground tanδ, and the damping ratio d are calculated using the following formulas:

[0016]

[0017]

[0018]

[0019]

[0020]

[0021] In the formula, and Let represent finding the imaginary and real parts of a complex number, respectively. This represents the change in voltage between the neutral point and ground. This represents the change in the primary ground current of a single-phase injection transformer. This represents the change in the ground current of the nth arc suppression coil; The angular frequency of the power supply; The angular frequency of the power distribution system; Phase voltage of the power distribution system; This is the rated current for the nth arc suppression coil operating position.

[0022] Secondly, a system for measuring ground parameters of a neutral-point grounded power distribution system via an active arc suppression device is provided, comprising a single-phase injection transformer or arc suppression coil grounded generator or power distribution network via a secondary winding for power injection at the neutral point, and further comprising:

[0023] The power output circuit impedance set within the power supply, including the first impedance. Second impedance First impedance The second impedance is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil. It is connected in parallel to the two ends of the secondary winding of a single-phase injection transformer or the secondary winding of an arc suppression coil;

[0024] The power supply is used to inject power frequency signals by adjusting the magnitude and / or phase of its output power signal and / or adjusting its power output impedance;

[0025] The data measurement module is used to measure the neutral point-to-ground voltage before and after the power supply regulation, the primary ground current of the single-phase injection transformer, and the ground current of each arc suppression coil.

[0026] A data calculation module, connected to the data measurement module, is used to calculate the power distribution system's ground parameters based on the data measured by the data measurement module.

[0027] Furthermore, the power output circuit impedance specifically includes a first impedance. Second impedance First to fourth switches, first impedance After being connected in series with the third switch, the entire assembly is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil; the second impedance The first switch is connected in series with the second switch and then in parallel across the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil; the first switch is connected in series with the power supply and the first impedance. Between the taps; the fourth switch is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil, and is connected to the first impedance. in parallel.

[0028] This invention proposes a method and system for measuring ground parameters in a neutral-point grounded power distribution system with an active arc suppression device. Compared with the prior art, it has the following advantages:

[0029] (1) The operation and control methods are simple and reliable: This invention directly uses the active arc suppression device to regulate the magnitude and / or phase of the power signal, and / or regulate the power output impedance to realize the injection of power frequency signal. No external power injection equipment is required. The measurement signal is large and the anti-interference ability is strong, which is suitable for the development of active grounding technology.

[0030] (2) Improve the reliability of power supply and measurement accuracy of the system: The present invention is applied to the neutral point through the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil for regulation. It does not affect the structure of the power distribution network system, eliminates the influence of the neutral point voltage deviation on the measurement accuracy, and the measurement process is safe and reliable. It realizes the accurate measurement of ground parameters of the resonant grounding system and can be used for ground fault detection, arc suppression and protection. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the ground parameter measurement structure of a neutral point grounded power distribution system provided in an embodiment of the present invention;

[0033] Figure 2 This is a simplified diagram of the power output circuit impedance provided in an embodiment of the present invention;

[0034] Figure 3 This is an equivalent circuit diagram for measuring ground parameters provided in an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram illustrating the principle of precise control of the power output impedance of the active arc suppression device provided in this embodiment of the invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0037] This embodiment provides a ground parameter measurement system for a neutral-point grounded power distribution system via an active arc suppression device, including a single-phase injection transformer or arc suppression coil grounded generator or power distribution network with power injected through a secondary winding at the neutral point, and further including:

[0038] The power output circuit impedance is set within the power supply, the power output circuit impedance including the first impedance. Second impedance First impedance The second impedance is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil. It is connected in parallel to the two ends of the secondary winding of a single-phase injection transformer or the secondary winding of an arc suppression coil;

[0039] The power supply is used to inject power frequency signals by adjusting the magnitude and / or phase of its output power signal and / or adjusting its power output impedance;

[0040] The data measurement module is used to measure the neutral point-to-ground voltage before and after the power supply regulation, the primary ground current of the single-phase injection transformer, and the ground current of each arc suppression coil.

[0041] A data calculation module, connected to the data measurement module, is used to calculate the power distribution system's ground parameters based on the data measured by the data measurement module.

[0042] The neutral point grounding distribution system with an active arc suppression device provided in the above embodiments can directly utilize the active arc suppression device to adjust the magnitude and / or phase of the power signal and / or adjust the power output impedance to achieve power frequency signal injection. No external power injection equipment is required. The measurement signal is large, the anti-interference ability is strong, and it is adapted to the development of active grounding technology. It is controlled by injecting a single-phase transformer secondary winding or an arc suppression coil secondary winding at the neutral point, without affecting the distribution network system structure, eliminating the influence of neutral point voltage deviation on measurement accuracy, and ensuring the measurement process is safe and reliable, thus achieving accurate measurement of ground parameters of the resonant grounding system.

[0043] like Figure 1 As shown, this is an example of a power distribution system with a neutral point injected into the secondary winding of a single-phase injection transformer to ground the power supply. , , The three phases are the system's three-phase power supply potential, C0 is the system's capacitance to ground, G0 is the system's leakage conductance to ground, T1 is a Z-type grounding transformer, and the secondary side is equipped with a feedback line voltage switching switch. x b x c x (x=1,2), T2 is an adjustable voltage single-phase injection transformer, S is a power input control switch, and L0 is an arc suppression coil. The turns ratio of the primary and secondary windings of the grounding transformer T1 is N1:N2, and the primary and secondary turns ratio K of the single-phase injection transformer T2 is adjustable. During normal operation of the power distribution system, the magnitude or phase of the voltage or current source is adjusted, or the output impedance of the voltage source is adjusted, controlling the neutral point-to-ground voltage range to 1%–15% of the phase voltage of the power distribution system. The voltage of the neutral point to ground in the system is measured in real time. Primary ground current of a single-phase injection transformer (The current injected into the power distribution system via the secondary winding of the arc suppression coil at the neutral point is also called the primary ground current injected into the transformer in a single-phase power distribution system.) and the ground current of each arc suppression coil. Calculate the change in neutral point voltage to ground Δ before and after the control signal. Change in primary ground current of single-phase injection transformer and the change in ground current of each arc suppression coil Δ Among them, when When the neutral point offset voltage, the primary ground offset current of the single-phase injection transformer, and the ground offset current of the arc suppression coil are respectively under normal operating conditions, then These are the neutral point offset voltage after the first power supply signal injection, the primary ground offset current of the single-phase injection transformer, and the ground offset current of the arc suppression coil, respectively; when These are the neutral point offset voltage after the first power supply signal injection, the primary ground offset current of the single-phase injection transformer, and the ground offset current of the arc suppression coil, respectively. These are the neutral point offset voltage after the second power supply signal injection, the primary ground offset current of the single-phase injection transformer, and the ground offset current of the arc suppression coil, respectively.

[0044] Simplified diagram of power supply output circuit impedance as follows Figure 2 As shown, This refers to the series impedance connecting the voltage source to the secondary winding of the single-phase injection transformer or arc suppression coil. For the parallel impedance across the secondary winding of a single-phase injection transformer or arc suppression coil, the resistance value of impedance Z1 controlled by switch K1 is selected, and the on / off state of impedance Z2 controlled by switch K2 is determined. The equivalent circuit diagram for measuring the ground parameters converted to the primary side is shown below. Figure 3 As shown, , They are respectively The value is attributed to the primary side. Based on this, the power distribution system's ground parameters can be calculated based on the changes in the neutral point-to-ground voltage, the changes in the primary current injected into the single-phase transformer, and the changes in the current injected into each arc suppression coil. These power distribution system ground parameters include one or more of the following: ground capacitance, ground leakage conductance, ground capacitance current, detuning degree, ground dielectric loss, and damping rate.

[0045] Specifically, capacitance to ground Leakage conductivity to ground ground capacitance current The detuning degree ν, the dielectric loss to ground tanδ, and the damping ratio d are calculated using the following formulas:

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] In the formula, and Let represent finding the imaginary and real parts of a complex number, respectively. This represents the change in voltage between the neutral point and ground. This represents the change in the primary ground current of a single-phase injection transformer. This represents the change in the ground current of the nth arc suppression coil; The angular frequency of the power supply; The angular frequency of the power distribution system; Phase voltage of the power distribution system; This is the rated current for the nth arc suppression coil operating position.

[0052] like Figure 4 The diagram shown is a schematic diagram of the principle of precise control of the power output impedance of an active arc suppression device. Figure 4 Taking a power distribution system with the neutral point injected into the ground via the secondary winding of the arc suppression coil as an example, in specific implementation, the power output circuit impedance specifically includes the first impedance. Second impedance First to fourth switches, first impedance With the third switch K 2-2 After being connected in series, the entire assembly is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil; the second impedance With the second switch K 2-1After being connected in series, the entire assembly is connected in parallel across the secondary winding of a single-phase injection transformer or the secondary winding of an arc suppression coil; the first switch K1 is connected in series between the power supply and the first impedance. Between the taps; the fourth switch K4 is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil, and is connected to the first impedance. Parallel connection. It should be noted that the second switch K... 2-1 and the third switch K 2-2 It can be two independent switches, but in practical engineering applications, the second switch K is preferred. 2-1 and the third switch K 2-2 The two contacts of switch K2 are used to control the second switch K. 2-1 and the third switch K 2-2 Simultaneous closing or simultaneous opening. In the diagram, the fourth switch K4 controls the active arc suppression device to inject arc suppression, K5-K 11 For the single-phase injection transformer control position, when K4 is closed, arc suppression can be achieved by controlling the single-phase injection transformer control position. Based on this, this embodiment adds a first impedance. Second impedance Together with the corresponding switches, they constitute the power supply output circuit impedance. Preferably, it also includes a second impedance connected in series with the power supply. The switch K3 is used to determine the fault type during arc suppression, whether it is a transient or permanent fault.

[0053] When controlling the power supply output circuit impedance, first control switch K. 2-1 K 2-2 And the control switch of a single-phase injection transformer is closed, the first impedance Second impedance If all power is engaged, and the measured residual current of the power distribution system is low, it will not exceed the preset setting value. If the impedance is adjusted again, then no further adjustment is needed; conversely, if the residual current in the power distribution system is large and exceeds the preset setting value, then no further adjustment is needed. At that time, the control switch K1 and the control position of a single-phase injection transformer are closed, and the second impedance... No input, resistance Partial access. Among them, The accuracy is determined based on the instrument monitoring values ​​in actual engineering projects.

[0054] Based on the ground parameter measurement system for a power distribution system grounded by an active arc suppression device provided in the above embodiments, this invention also provides a method for measuring ground parameters of a power distribution system grounded by an active arc suppression device based on this system. This method is applied to the measurement of ground parameters of a single-phase injection transformer or an arc suppression coil grounded generator or power distribution network with power injected through a secondary winding at the neutral point. The method includes the following steps:

[0055] S1: During normal operation of the power distribution system, power frequency signal injection is achieved by adjusting the magnitude and / or phase of the power output signal and / or adjusting the power output impedance.

[0056] S2: Measure the neutral point-to-ground voltage before and after the power supply regulation, the primary ground current of the single-phase injection transformer, and the ground current of each arc suppression coil;

[0057] S3: Calculate the ground parameters of the power distribution system based on the measured data.

[0058] In practice, there are seven ways to inject power frequency signals by regulating the power supply. These include selecting any one, any combination of two, or a combination of three of the following: regulating the power supply signal magnitude, regulating the power supply signal phase, and regulating the power supply output impedance. However, during the regulation of the power supply, the neutral point to ground voltage range is controlled to be 1% to 15% of the phase voltage of the power distribution system.

[0059] More specifically, the magnitude of the power output signal is controlled by adjusting the control level of the single-phase injection transformer. Figure 4 Switches K5-K in 11 This is achieved by controlling the phase of the power supply output signal through a feedback line voltage switching switch. Figure 1 a in x b x c x (x=1,2)) This can be achieved. Alternatively, the control range of the single-phase injection transformer and the feedback line voltage switching switch can be adjusted simultaneously to achieve simultaneous control of magnitude and phase. In this embodiment, the power frequency signal is injected for measurement, and then the changes in neutral point-to-ground voltage, the changes in primary ground current of the single-phase injection transformer, and the changes in ground current of each arc suppression coil are measured. The measurement signal is large, the anti-interference ability is strong, and the measurement accuracy can be guaranteed. The traditional method is to inject a non-power frequency signal, which is a disturbance signal relative to the power frequency signal. It is also affected by the frequency of the injected non-power frequency signal and cannot capture the signal in a high current (residual current) system, resulting in large measurement errors and low accuracy. Of course, it should be noted that, in order to ensure circuit safety, when adjusting the magnitude and / or phase of the power output signal, the impedance of the power output circuit can be adjusted. , All invested, or only Investment.

[0060] When adjusting the power supply output impedance: During normal operation of the power distribution system, complete one data measurement, and then... Figure 4 switch K 2-1 K 2-2 closure, , Fully engage the system, determine the system parameter (e.g., residual current of the distribution system) range, and avoid overvoltage. This will complete one data measurement. Then, based on the initially determined residual current range of the distribution system, if the measurement result does not exceed the preset setting value, maintain the current switch state. At this point, switch K... 2-1 K 2-2 closure, , Once fully engaged, a single power frequency signal injection is completed; if the measurement result exceeds the preset setting value, selector switch K1 closes, and the second impedance... No input, first impedance Partial connection, then complete data measurement on one side, at this time, the previous switch K 2-1 K 2-2 closure, , The first power frequency signal injection is completed when all components are engaged; switch K1 is closed, and the second impedance... The second power frequency signal injection is completed without any input. The output circuit impedance of this power supply serves as both current limiting and voltage dividing, therefore, there is no need to adjust the voltage level (the neutral point voltage is already controlled). The range is 1%–15% of the system phase voltage. In practice, the output impedance of the power supply can be combined with the magnitude and / or phase of the output power signal to inject a power frequency signal. While adjusting the magnitude and / or phase of the power supply allows for more direct signal measurement, its accuracy is slightly compromised by the range setting, potentially affecting the system. Adjusting the output impedance eliminates the need for range adjustment, as the impedance voltage division injects a constant signal, resulting in greater precision. The advantages of using the output impedance of the power supply are: 1. Simple and clear measurement method; 2. Range-based measurement based on the residual current of the power distribution system, eliminating the possibility of excessively high neutral point voltage due to measurement; 3. High measurement reliability due to impedance division; 4. Selectable injection phase angle; 5. Reduced number of range adjustments required for the magnitude and / or phase of the power supply.

[0061] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0062] The following section provides further explanation of the power distribution system ground parameter measurement scheme of the present invention through specific experiments. For example... Figure 1 As shown, in the grounded power distribution system of the active arc suppression device, the three-phase power supply potential... = = =10 / kV; the turns ratio of a single-phase injection transformer or the turns ratio of the primary and secondary windings of an arc suppression coil. The ratio is 6062:1040; =700Ω, with a 160Ω tap connected to K1; =35Ω, at which point the impedance value meets the range for precise voltage measurement. Power is supplied through an active arc suppression device. Injecting a signal to control the neutral point to ground voltage range to 1%–15% of the system phase voltage, and changing the ground insulation parameters of the system ground capacitance, the test results are shown in Table 1.

[0063]

[0064] The data above shows that the measurement method has high accuracy in measuring ground capacitance current and the test results are ideal. It is suitable for measuring ground parameters in grounding power distribution systems with active arc suppression devices.

[0065] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for measuring ground parameters in a neutral-point grounded power distribution system using an active arc suppression device, characterized in that, The method for measuring ground parameters of single-phase injection transformers or grounded generators or distribution networks with power injected through secondary windings at the neutral point includes the following steps: During normal operation of the power distribution system, power frequency signal injection is achieved by adjusting the magnitude and / or phase of the power signal output by the active arc suppression device, and / or adjusting the power output impedance of the active arc suppression device. Measure the neutral point-to-ground voltage before and after the power supply regulation, the primary ground current of the single-phase injection transformer, and the ground current of each arc suppression coil; Calculate the power distribution system's ground parameters based on the measured data; The power distribution system's ground parameters include one or more of the following: ground capacitance, ground leakage conductance, ground capacitance current, detuning degree, ground dielectric loss, and damping rate. capacitance to ground Leakage conductivity to ground ground capacitance current The detuning degree ν, the ground dielectric loss tanδ, and the damping ratio d are calculated using the following formulas: ； ； ； ； ； In the formula, and Let represent finding the imaginary and real parts of a complex number, respectively. This represents the change in voltage between the neutral point and ground. This represents the change in the primary ground current of a single-phase injection transformer. This represents the change in the ground current of the nth arc suppression coil; The angular frequency of the power supply; The angular frequency of the power distribution system; Phase voltage of the power distribution system; This is the rated current for the nth arc suppression coil operating position.

2. The method for measuring ground parameters in a neutral-point grounded power distribution system with an active arc suppression device according to claim 1, characterized in that, The power supply output impedance is adjusted by regulating the power supply output circuit impedance, including the first impedance. Second impedance , where the first impedance The second impedance is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil. It is connected in parallel to both ends of the secondary winding of a single-phase injection transformer or the secondary winding of an arc suppression coil.

3. The method for measuring ground parameters in a neutral-point grounded power distribution system with an active arc suppression device according to claim 2, characterized in that, The impedance is adaptively adjusted based on the magnitude of the residual current in the power distribution system. When the residual current in the power distribution system does not exceed the preset setting value, the first impedance... Second impedance Fully engaged; conversely, when the residual current of the power distribution system exceeds the preset setting value, the second impedance... No input, only the first impedance is input. .

4. The method for measuring ground parameters in a neutral-point grounded power distribution system with an active arc suppression device according to claim 1, characterized in that, The magnitude of the power output signal is controlled by adjusting the control range of the single-phase injection transformer.

5. The method for measuring ground parameters in a neutral-point grounded power distribution system with an active arc suppression device according to claim 1, characterized in that, Phase control of the power output signal is achieved by controlling the feedback line voltage switching switch.

6. The method for measuring ground parameters in a neutral-point grounded power distribution system with an active arc suppression device according to claim 1, characterized in that, During the power supply regulation process, the neutral point-to-ground voltage range is controlled to be 1% to 15% of the phase voltage of the power distribution system.

7. A system for measuring ground parameters in a neutral-point grounded power distribution system using an active arc suppression device, characterized in that, A method for measuring ground parameters in a neutral-point grounded distribution system as described in any one of claims 1 to 6, the system comprising a single-phase injection transformer or an arc-suppression coil grounded generator or distribution network with power injected through a secondary winding at the neutral point, further comprising: The power output circuit impedance set within the power supply, including the first impedance. Second impedance First impedance The second impedance is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil. It is connected in parallel to the two ends of the secondary winding of a single-phase injection transformer or the secondary winding of an arc suppression coil; The power supply is used to inject power frequency signals by adjusting the magnitude and / or phase of its output power signal and / or adjusting its power output impedance; The data measurement module is used to measure the neutral point-to-ground voltage before and after the power supply regulation, the primary ground current of the single-phase injection transformer, and the ground current of each arc suppression coil. A data calculation module, connected to the data measurement module, is used to calculate the power distribution system's ground parameters based on the data measured by the data measurement module.

8. The ground parameter measurement system for a neutral point grounded power distribution system with an active arc suppression device according to claim 7, characterized in that, The power output circuit impedance specifically includes a first impedance. Second impedance First to fourth switches, first impedance After being connected in series with the third switch, the entire assembly is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil; the second impedance The first switch is connected in series with the second switch and then in parallel across the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil; the first switch is connected in series with the power supply and the first impedance. Between the taps; the fourth switch is connected in series between the power supply and the secondary winding of the single-phase injection transformer or the secondary winding of the arc suppression coil, and is connected to the first impedance. in parallel.

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