CN107611958A - Automatic tracking and compensating arc distinction system for generator neutral point - Google Patents

Abstract

The invention provides a kind of automatic tracking and compensating arc distinction system for generator neutral point, it is characterized in that, including arc suppression coil module and core controller, core controller is connected with arc suppression coil module, Tuning Control and operational monitoring for arc suppression coil module；Wherein：Arc suppression coil module includes：Arc suppression coil, load ratio bridging switch, secondary winding, thyristor switch and damping resistance, secondary winding is wound on the iron core of arc suppression coil, secondary winding is connected in parallel through thyristor switch and damping resistance, load ratio bridging switch is arranged at the primary side of arc suppression coil, for picking out one or more joints in the primary side of arc suppression coil.The present invention can be achieved to optimize multicomputer or the automatic tracking and compensating of the monitoring of more parent segment paired runnings and arc suppression coil, avoid major safety risks existing for existing product, ratio of damping is invariable, all the time in optimal damping effect, the defects of avoiding damping unstable.

Description

Automatic Tracking Compensation Arc Suppression System for Neutral Point of Generator

technical field

The invention relates to the technical field of automatic compensation for neutral point grounding arc suppression in power systems, in particular to an automatic tracking compensation arc suppression system for neutral point of a generator.

Background technique

The neutral point grounding method is a very complicated issue. It is necessary to consider all aspects of power system operation and control. The operation mode of a power grid depends on the specific situation, but there is no doubt that the neutral point The arc-suppression coil grounding method has been proved to have significant advantages in practice, especially for some applications where safety issues and high power supply reliability are to be considered, it is more important to ground the neutral point through the arc-suppression coil. Considering the problem of limiting the capacitive current from the perspective of the grounding method, the neutral point is grounded through the arc suppressing coil is the only choice.

The compensation effect of the arc suppressing coil has a great relationship with its detuning degree. Only by tuning the proper arc suppressing coil can the ideal effect be achieved, and the power grid will change, so its single-phase grounding capacitor current will change accordingly, which requires people to Adjust the compensation current of the arc suppression coil according to the change of the power grid. This kind of work is not only cumbersome, but also in many occasions it is difficult to manually tune the arc suppression coil in time and accurately, so it is very necessary to realize the automatic tuning of the arc suppression coil. This needs to solve two problems, one is to have an automatically adjustable arc suppression reactor, and the other is to have a control system for accurate tuning. In addition, after a single-phase ground fault occurs in the power grid, it is very important to quickly and accurately find the ground fault, remove the fault line in time and restore the normal operation of the power grid. This is also one of the problems that have long puzzled the small current grounding system.

Installing an arc suppression coil at the neutral point is one of the effective methods to control zero-sequence faults. It can control the grounding residual current and effectively suppress arc overvoltage and ferromagnetic resonance overvoltage and other hazards.

The turn-adjusting arc suppression system is the most reliable in operation among all kinds of arc suppression products, and its structure design is simple, and the cost is relatively low. Therefore, the turn-adjusting arc suppression system has become the mainstream product in the arc suppression industry. The turn-adjusting arc suppression system belongs to the pre-compensation arc suppression system. In order to prevent the series resonance between the ground capacitance of the power grid and the arc suppression coil during normal operation, a damping resistor needs to be connected to suppress it. The traditional turn-adjusting arc suppression system suppresses series resonance by connecting the damping resistor in series on the primary side, that is, using the method of direct series connection with the orphan elimination coil, referred to as the high-voltage series method, which will cause the following two problems:

1. When the damping resistor is connected in series, since the resistance value remains unchanged, the damping rate also changes with the change of the working tap of the arc suppression coil, and the damping effect is unstable;

2. The damping resistor is placed on the high-voltage side (primary side). During the transient transition process of the grid grounding and grounding disappearance, the damping resistor withstands overvoltage and overcurrent. It is required that the main insulation and inter-turn insulation of the damping resistor should have a certain strength. And enough heat capacity, if the manufacturing process is a little careless, it may cause damage, so it is relatively difficult to protect the damping resistor and it is easy to burn out.

Do not find description or report similar to the present invention at present, also do not collect similar data both at home and abroad.

Contents of the invention

Aiming at the above-mentioned deficiencies in the prior art, the present invention provides an automatic tracking and compensating arc suppression system for the neutral point of a generator.

The present invention is achieved through the following technical solutions.

An automatic tracking and compensation arc suppression system for the neutral point of a generator, including an arc suppression coil module and a core controller, the core controller is connected with the arc suppression coil module, and is used for automatic tuning control of the arc suppression coil module and operation monitoring; among them:

The arc suppression coil module includes: an arc suppression coil, an on-load tap changer, a secondary winding, a thyristor switch and a damping resistor, the secondary winding is wound on the iron core of the arc suppression coil, and the secondary winding is passed through a thyristor The switch is connected in parallel with the damping resistor, and the on-load tap changer is arranged on the primary side of the arc-suppression coil, and is used for on-load tap-changing of multiple taps of the arc-suppression coil.

Preferably, the arc suppression coil is a turn-adjustable arc suppression coil.

Preferably, in the full compensation state, the damping ratio of the damping resistor to the grid is constant.

Preferably, the resistance value of the damping resistor is determined by the number of turns of any gear of the arc suppression coil.

Preferably, the arc suppressing coil module further includes a damping resistance box, and the damping resistance is arranged in the damping resistance box.

Preferably, it is characterized in that the core controller includes a monitoring host and an arc suppression controller, the monitoring host includes a CAN bus interface, and the monitoring host communicates with the arc suppression controller through the CAN bus interface; wherein:

The monitoring host also includes any one or more of the following interfaces:

-USB interface, used to export the grid data collected by the arc suppression controller;

- Display module interface, used to connect to display components and provide human-computer interaction interface;

-Printer interface for accessing printer components;

-Serial communication interface, used to access the integrated automation system;

The arc suppression controller includes the following modules:

-Master board module, used to track and measure the change value of grid capacitance current;

- The arc suppression drive board module is used to pre-adjust the inductance of the arc suppression coil module;

- Remote signal remote control board module, used for automatic tracking and tuning to control the arc suppression coil module;

-The line selection board module is used for line selection of faulty branches in the power grid.

Preferably, the serial communication interface includes RS232, RS422 and/or RS458 serial interfaces.

Preferably, the arc suppression controller detects the capacitive current of the power grid by sampling the neutral point voltage signal, samples the neutral point voltage value U ₀ according to the set capacitive current detection sensitivity, and decides whether to restart the arc according to the variation of U ₀ Detect capacitor current; wait for ground fault to occur;

When a single-phase ground fault occurs, the arc-suppression controller cuts off the damping resistance, and the arc-suppression coil module enters a full compensation state; Data collection of branch zero-sequence current and zero-sequence voltage, and line selection of faulty branches in the power grid through the line selection board module; , put in the damping resistor, and return to the state of detecting the capacitive current of the power grid. 10 cycles for data recording.

Preferably, the principle of determining whether to re-detect the capacitive current according to the variation of the voltage value of U0 is: when U0 is greater than the starting voltage corresponding to the _set capacitive current detection sensitivity, re-detect the capacitive current.

Preferably, the arc suppression controller transmits the normal operation status information of the arc suppression coil module and the grounding status information to the integrated automation system through the serial communication interface of the monitoring host.

Compared with the prior art, the present invention has the following beneficial effects:

1. Real-time performance. The present invention processes and diagnoses the sampling data in real time, adopts multi-thread technology, and controls the running time in real time.

2. Effectiveness, the present invention can effectively diagnose partial discharge, because the detection of partial discharge signal is affected by various factors and presents uncertainty, so the present invention is on the basis of partial discharge theory, with the help of intelligent diagnosis method, for faults in the power grid The branch is judged.

3. Modular design. The present invention adopts modular design to make the structure clear, each part is relatively independent and easy to cooperate, and the structure is simple and easy to realize.

4. Scalability, the present invention meets the requirements of different environments by designing different interfaces, and expands the scope of application and service life of the system.

5. The user interface is friendly. The present invention can flexibly set different parameters according to specific conditions, and the system is simple, convenient and easy to maintain.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Figure 1 is a schematic diagram of the structure of the arc suppression coil module taking the arc suppression coil as an example. (a) is a schematic diagram of the connection structure of the damping resistor r _z , and (b) is the high voltage side (secondary side) when the i-th tap is working. ) equivalent circuit diagram;

Fig. 2 is the hardware structural block diagram of core controller;

Fig. 3 is the working flow diagram of the arc suppression controller;

Figure 4 shows the recorded waveforms of neutral point voltage and current at the beginning of single-phase grounding;

Figure 5 shows the recorded waveforms of neutral point voltage and current at the end of single-phase grounding.

detailed description

The following is a detailed description of the embodiments of the present invention: this embodiment is implemented on the premise of the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Example

An automatic tracking and compensation arc suppression system for the neutral point of a generator, including an arc suppression coil module and a core controller, the core controller is connected with the arc suppression coil module, and is used for automatic tuning control of the arc suppression coil module and operation monitoring; among them:

The arc suppression coil module includes: an arc suppression coil, an on-load tap changer, a secondary winding, a thyristor switch and a damping resistor, the secondary winding is wound on the iron core of the arc suppression coil, and the secondary winding is passed through a thyristor The switch is connected in parallel with the damping resistor, and the on-load tap changer is arranged on the primary side of the arc-suppression coil, and is used for on-load tap-changing of multiple taps of the arc-suppression coil.

Further, the arc suppression coil is a turn-adjustable arc suppression coil.

Further, in the full compensation state, the damping rate of the damping resistor to the grid is constant.

Further, the resistance value of the damping resistor is determined by the number of turns of any gear of the arc suppression coil.

Further, the arc suppressing coil module further includes a damping resistance box, and the damping resistance is arranged in the damping resistance box.

Further, it is characterized in that the core controller includes a monitoring host and an arc suppression controller, the monitoring host includes a CAN bus interface, and the monitoring host communicates with the arc suppression controller through the CAN bus interface; wherein:

The monitoring host also includes any one or more of the following interfaces:

-USB interface, used to export the grid data collected by the arc suppression controller;

- Display module interface, used to connect to display components and provide human-computer interaction interface;

-Printer interface for accessing printer components;

-Serial communication interface, used to access the integrated automation system;

The arc suppression controller includes the following modules:

-Master board module, used to track and measure the change value of grid capacitance current;

- The arc suppression drive board module is used to pre-adjust the inductance of the arc suppression coil module;

- Remote signal remote control board module, used for automatic tracking and tuning to control the arc suppression coil module;

-The line selection board module is used for line selection of faulty branches in the power grid.

Further, the serial communication interface includes RS232, RS422 and/or RS458 serial interface.

Further, the arc suppression controller detects the capacitive current of the power grid by sampling the neutral point voltage signal, samples the neutral point voltage value U ₀ according to the set capacitive current detection sensitivity, and decides whether to restart the arc according to the variation of U ₀ Detect capacitor current; wait for ground fault to occur;

When a single-phase ground fault occurs, the arc-suppression controller cuts off the damping resistance, and the arc-suppression coil module enters a full compensation state; Data collection of branch zero-sequence current and zero-sequence voltage, and line selection of faulty branches in the power grid through the line selection board module; , put in the damping resistor, and return to the state of detecting the capacitive current of the power grid. 10 cycles for data recording.

Further, the principle of determining whether to re-detect the capacitive current according to the variation of the voltage value of U ₀ is: when U ₀ is greater than the start-up voltage corresponding to the set capacitive current detection sensitivity, re-detect the capacitive current.

Further, the arc suppression controller transmits the normal operation status information of the arc suppression coil module and the grounding status information to the integrated automation system through the serial communication interface of the monitoring host.

This embodiment will be further described below in conjunction with the accompanying drawings.

The automatic tracking compensation arc suppression system for generator neutral point provided by this embodiment mainly consists of arc suppression coil module (including arc suppression coil with secondary winding turn adjustment, on-load tap changer, damping resistance box) and core Controller (including monitoring host, arc suppression controller). This embodiment is applied in the power grid of a power plant, and its typical application is: install a set of automatic tracking compensation arc suppression system provided by this embodiment at the neutral point of each generator. When each generator runs in parallel, the automatic tracking compensation arc suppression system also Enter the state of multi-machine and one-change parallel operation. The arc suppression controller completes the automatic tuning control and parallel operation monitoring of the arc suppression coils.

In this embodiment, the arc-suppression coil module is equipped with a secondary winding on the turn-adjustable arc-suppression coil, and the damping resistor is placed on the secondary side, which solves the problem of the series damping-turn-adjustable arc-suppression and improves the turn-adjustable arc-suppression Coil, the arc suppressing coil with constant damping rate of solid line. The structure of the arc suppression coil module is briefly described as follows:

As shown in Figure 1(a), a secondary winding is wound on the iron core of the turn-adjusting arc suppression coil, and the damping resistor r _z is connected to the secondary winding through the thyristor switch K. When the power grid is operating normally, the switch K Close, increase the damping rate of the grid to limit the neutral point displacement voltage within 15% of the phase voltage, and open the switch K when a single-phase ground fault occurs to ensure the compensation effect of the arc suppression coil.

As shown in Figure 1(b), when the turn-adjustable arc-suppression coil works on different taps, the equivalent damping resistance changes due to the change of the number of turns on the primary side. The number is N _1i , the reactance is X _Li , the number of turns of the secondary side winding is N ₂ , and the total capacitance of the grid to ground is C _Σ , then the equivalent damping resistance R _i of the i-th tap = (N _1i /N ₂ ) ² r _z , the damping rate of the damping resistor to the grid:

When the turn-adjustable arc suppressing coil is tuned to be close to full compensation, X _C ≈ X _iL , then:

In the formula, X ₂ ＝(N ₂ /N _1i ) ² X _Li , because the secondary winding and the primary winding are wound on the same iron core with air gap, in the case of ignoring the leakage reactance, X ₂ is the turn-adjusting type elimination The reactance corresponding to the secondary winding of the arc coil is equal to the input reactance of the secondary side when the primary side of the turn-adjusting arc suppression coil is open, and the value is determined after the turn-adjusting arc suppression coil is manufactured, and it is constant. It can be seen that the damping rate of the damping resistor to the grid is constant when fully compensated.

In addition, in terms of the capacity selection of the turn-adjustable arc suppression coil (hereinafter referred to as the arc suppression coil), the rated voltage of the arc suppression coil is the voltage acting on the top of the main winding at the rated frequency under normal operating conditions, and its value should be equal to System nominal voltage divided by That is 6062V. According to DL/T620-1997 "Overvoltage Protection and Insulation Coordination of AC Electrical Installations", the capacity of the arc suppression coil should be determined according to the development plan of the system for 5 to 10 years, and calculated according to the following formula:

Among them: W - the capacity of the arc suppression coil, kVA;

I _C ——ground capacitance current, A;

U _n ——system nominal voltage, kV.

In order to obtain the best compensation effect, the automatic tracking compensation arc suppression system provided by this embodiment may operate in a critical resonance state. In order to prevent the displacement voltage of the automatic tracking compensation arc suppression system from exceeding the limit, it is necessary to install a damping resistor, which is located in the damping resistance box. middle. As far as damping resonance is concerned, both series and parallel resistors are effective. At present, the method of direct series connection with the desolation coil is adopted in China, referred to as the high-voltage series method. The disadvantage of this method is that in the transient transition process of grid grounding and grounding disappearance, the damping resistor is subjected to overvoltage and overcurrent, and the main insulation and turn-to-turn insulation of the damping resistor should have a certain strength and sufficient heat capacity. . Slight carelessness in manufacturing process may result in damage. In addition, since the resistance value is constant, the damping rate of the power grid is also different with the gear position of the arc suppression coil. For this reason, the method of combining the secondary winding of the arc suppressing coil with resistance is adopted, which has the advantages of safety and reliability, and constant damping rate of the power grid.

The principle of determining the resistance value of the damping resistor is as follows:

According to the requirements of the regulations, the neutral point displacement voltage reaches the maximum value when fully compensated:

In the formula, K _c is the natural unbalance degree of the power grid, which is generally (0.5-1.5)%, d is the inherent damping law of the power grid, and the value is generally (0.3-5)%, and U _φ is the phase voltage of the power grid. When K _c =1.5%, substitute into the above formula to get:

Take K _c =1.5%, d=3% and substitute them into formula (5), the damping resistance r _z <14.3X ₂ =14.3(N ₂ /N _1i ) ² X _Li . It can be seen that as long as the number of turns of any gear of the arc suppression coil is known, the damping resistance can be determined. Compared with the turn-adjustable arc suppression coil with series damping resistance, the arc suppression coil with constant damping law has advantages.

Figure 2 is the hardware block diagram of the core controller, including the monitoring host and the arc suppression controller. The monitoring host is responsible for display, man-machine interface, and communication with the integrated system. The monitoring host can adopt industrial control computer boards, and the storage adopts 2G capacity CF cards.

The arc suppression controller is responsible for arc suppression control and line selection functions, including neutral point displacement voltage, neutral point current, phase voltage and zero-sequence current analog input channel of each line selection branch, on-load switch gear signal, remote control signal , Bus coupler switch status and dual parallel operation signal switch input channel, shift control signal, remote signal switch output channel, and CPU system. The CPU system can use TI's high-speed DSP chip with a main frequency of 150MHz. The arc suppression controller adopts a modular design, and each module can be expanded according to the actual situation.

The monitoring host and arc suppression controller communicate through CAN communication. The arc suppression controller can complete the arc suppression control independently from the monitoring host. Even if the monitoring host fails, it can still ensure the normal operation of the arc suppression system and improve the reliability of the system.

In this example:

The monitoring host (host computer) is responsible for displaying relevant information to the user, such as the capacitor current calculated by the auto-tuning controller, current gear information, grounding alarm information, recorded waveform, and the current operating status of the arc suppression system. The current actual situation sets the system configuration.

The monitoring host can use a 7" color LCD display, which has an excellent man-machine interface, and the operation is intuitive, simple and convenient. The monitoring interface is equipped with a control parameter and control mode database and a historical database, which can easily set control parameters and modify the operation mode. While the controller performs real-time control of the arc suppression coil, a large amount of historical data of the historical database is analyzed.

The arc suppression controller (lower computer) is the control center of the automatic tracking compensation arc suppression system, which is responsible for real-time tracking and measurement of changes in the capacitance and current of the grid, pre-adjusting the inductance of the arc suppression coil, and realizing automatic tracking and tuning. When a single-phase grounding occurs in the power grid, the damping resistance is cut off to implement compensation.

The CPU of the arc suppression controller can use TI's fast DSP chip, which is stable, reliable, and high-speed, with a main frequency of 150MHz; Direct AC sampling and full digital processing of neutral point voltage and reference voltage, combined with photoelectric isolation technology, completely eliminate harmonic interference and electromagnetic interference; arc suppression controller adopts modular design, and each function is designed as an independent plug-in, which can Different requirements are combined into different systems.

The performance indicators of the automatic tracking compensation arc suppression system are as follows:

1) Adjustment depth of arc suppression coil (ratio of upper limit and lower limit of compensation current) 2.5;

2) The compensation current can be adjusted in stages, the maximum number of stages is 30;

3) The neutral point current resolution is less than 50mA;

4) Compensation current harmonic content is less than 1%;

5) Capacitive current detection accuracy is less than 2%;

6) Wave recording sampling rate 10kHz;

7) For a power grid with a capacitive current of less than 100A, the reactive component of the grounding residual current is less than 2A, and for a power grid with a capacitive current of less than 200A, the reactive component of the grounding residual current is less than 4A;

8) For the stable grounding phenomenon with the grounding time greater than 2s, the line selection accuracy rate of the grounding line selection device is 100%;

9) The maximum number of lines selected for a single unit is 48;

10) A maximum of 4 arc suppression coils can be controlled to run in parallel.

11) Working power supply:

AC220V±10％50Hz or DC220V±10％, DC110V±10％;

Power capacity: 118W.

Chassis Dimensions:

●Monitoring host: 19”×4U×273mm (width×height×depth);

●Controller unit: 19”×4U×260.5mm (width×height×depth);

Conditions of use of the device:

●Ambient temperature: -40℃～+55℃;

●Humidity: ≤90%; and no conductive dust exists;

●Atmospheric pressure: 80～110Kpa;

●Altitude generally does not exceed 2500 meters; if it exceeds 2500 meters, necessary technical treatment of the device is required;

●Installation site: indoors without corrosive metal and insulating gas and steam;

●No severe vibration and strong turbulence, and the level of the ground does not exceed 5 degrees.

As shown in Figure 3, the working flow chart of the arc suppression controller, the arc suppression controller realizes the capacitance current detection by sampling the U0 signal, according to the set capacitance current detection sensitivity, samples the U0 voltage value, and decides whether to re-detect the capacitance according to its variation Current; collect switch input information, judge single operation or double operation; transmit the normal operation status information of the arc suppression coil to the comprehensive self through serial communication; wait for the ground fault to occur.

When a single-phase grounding occurs, the arc suppression controller immediately cuts off the damping resistance, the arc suppression coil enters the compensation state, and an alarm signal is generated at the same time, and the grounding status information is transmitted to the comprehensive self through serial communication; , to collect data on the zero-sequence current and zero-sequence voltage of each branch before and after the resistor is put in, and use the zero-sequence current incremental method to select the line. The arc suppression controller makes a comprehensive judgment on the state of the power grid. After analysis, when it is determined that the fault safety disappears, the damping resistor is put in and returns to the detection state. At the same time, the arc suppression controller records the data of the neutral point voltage and neutral point current for 10 cycles before and after the grounding start time (as shown in Figure 4), and for 10 cycles before and after the end time (as shown in Figure 5 Show).

The state of the main switch of the power grid and the signal of double-unit parallel operation are used to set the arc suppression controller to the double-unit parallel operation state. In this case, two sets of dynamic compensation systems are allowed to operate in one power grid at the same time.

The automatic tracking compensation arc suppression system provided in this embodiment has the following characteristics:

Intelligent tracking and multi-machine operation

It can realize the parallel operation monitoring of multiple units or multiple bus sections and the automatic tracking compensation optimization of the arc suppression coil, ensuring

Under different operating modes, the flexibility and reliability of the automatic tracking compensation arc suppression system.

higher security

The damping resistor can be installed on the secondary side of the arc suppression coil, and the thyristor switching damping resistor is used to completely avoid the major safety hazards existing in existing products.

better damping effect

During the automatic tuning process of the grid capacitor current, the damping changes in proportion to the number of coil turns, and the damping rate remains constant, always in the best damping effect. The defect of unstable damping effect of existing products is avoided.

A better capacitive current measurement and tracking method:

The current measurement accuracy is within 2%, and the entire measurement and tracking algorithm uses the ratio of two measurements of the same signal as the basic parameter, completely avoiding the instability of measurement results and tracking caused by measurement channel errors and changes.

higher reliability

This embodiment adopts PC104+DSP dual CPU structure as the core controller, adopts strong and weak current isolation, isolated power supply, software and hardware watchdog, hardware continuous self-inspection technology, photoelectric isolation, and non-contact design to ensure high reliability of the system .

Recording function

Record the neutral point voltage and neutral point current when single-phase grounding occurs, and support historical data query and analysis, including the display of recorded waveforms and the output of recorded data.

Modular control system

The monitoring host is separated from the arc suppression controller, and the monitoring host can support up to four bus sections. Each functional module of the arc suppression controller is designed as an independent plug-in, which can be configured according to the needs of users.

smooth upgrade

The monitoring host and at least one arc suppression controller are connected by CAN bus communication, fully supporting the smooth upgrade of the control system.

more convenient to operate

The controller operation adopts the oscilloscope design style, which is simple and clear. It also supports manual operation. The user interface can be WINDOWS style, and the configuration and query can be completed in one click. Equipped with a 7" color LCD display, the operating status of the system is clear at a glance.

More complete historical data recording, query and export

The monitoring interface is equipped with operation log, control parameter and control mode database, grounding and wave recording database, which can conveniently check the operating status of the system, set control parameters and modify operation mode, and analyze grounding wave recording data. These historical data can also be easily exported through the USB interface.

Flexible Communication

The controller has RS-232, RS-422, RS-485 serial interfaces and communication components, can be used as a substation to access various comprehensive automation systems, and has functions of telemetry, remote signaling and remote control.

self-diagnosis function

The system has a self-diagnosis function, which can detect the abnormality of the device itself in time and inform the user.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (10)

1. An automatic tracking compensation arc suppression system for generator neutral point, characterized in that it includes an arc suppression coil module and a core controller, and the core controller is connected with the arc suppression coil module for arc suppression Automatic tuning control and operation monitoring of the coil module; where: The arc suppression coil module includes: an arc suppression coil, an on-load tap changer, a secondary winding, a thyristor switch and a damping resistor, the secondary winding is wound on the iron core of the arc suppression coil, and the secondary winding is passed through a thyristor The switch is connected in parallel with the damping resistor, and the on-load tap changer is arranged on the primary side of the arc-suppression coil, and is used for on-load tap-changing of multiple taps of the arc-suppression coil. 2. The arc suppression system for automatic tracking and compensation of the neutral point of the generator according to claim 1, wherein the arc suppression coil is a turn-adjustable arc suppression coil. 3. The automatic tracking compensation arc suppression system for generator neutral point according to claim 1, characterized in that, in the fully compensated state, the damping rate of the damping resistor to the grid is constant; the damping resistor The resistance value is determined by the number of turns of any gear of the arc suppression coil. 4. The arc suppression system for automatic tracking and compensation of generator neutral point according to claim 1, characterized in that, the arc suppression coil module further comprises a damping resistance box, and the damping resistance is arranged in the damping resistance box . 5. The automatic tracking compensation arc suppression system for generator neutral point according to any one of claims 1 to 4, characterized in that, the core controller includes a monitoring host and an arc suppression controller, the The monitoring host includes a CAN bus interface, and the monitoring host communicates with the arc suppression controller through the CAN bus interface; wherein: The monitoring host also includes any one or more of the following interfaces: -USB interface, used to export the grid data collected by the arc suppression controller; - Display module interface, used to connect to display components and provide human-computer interaction interface; -Printer interface for accessing printer components; -Serial communication interface, used to access the integrated automation system; The arc suppression controller includes the following modules: -Master board module, used to track and measure the change value of grid capacitance current; - The arc suppression drive board module is used to pre-adjust the inductance of the arc suppression coil module; - Remote signal remote control board module, used for automatic tracking and tuning to control the arc suppression coil module; -The line selection board module is used for line selection of faulty branches in the power grid. 6. The arc-suppression system for automatic tracking compensation for generator neutral point according to claim 5, characterized in that, the serial communication interface includes RS232, RS422 and/or RS458 serial interface. 7. The automatic tracking compensation arc suppression system for generator neutral point according to claim 5, characterized in that, the arc suppression controller detects the capacitive current of the power grid by sampling the neutral point voltage signal, according to Set the capacitance current detection sensitivity, sample the neutral point voltage value U ₀ , and decide whether to re-detect the capacitance current according to the variation of U ₀ ; wait for the ground fault to occur; When a single-phase ground fault occurs, the arc-suppression controller cuts off the damping resistance, and the arc-suppression coil module enters a full compensation state; Data collection of branch zero-sequence current and zero-sequence voltage, and line selection of faulty branches in the power grid through the line selection board module; , put in the damping resistor, and return to the state of detecting the capacitive current of the power grid. 10 cycles for data recording. 8. The automatic tracking compensation arc suppression system for generator neutral point according to claim 7, characterized in that, the principle of determining whether to re-detect the capacitive current according to the variation of U ₀ voltage value is: when U ₀ When it is greater than the starting voltage corresponding to the set capacitance current detection sensitivity, the capacitance current is re-detected. 9. The arc suppression system for automatic tracking compensation for generator neutral point according to claim 7, characterized in that the line selection board module selects the line of the fault branch in the power grid by using the zero-sequence current incremental method. 10. The arc suppression system for automatic tracking and compensation of generator neutral point according to claim 7, characterized in that, the arc suppression controller transmits the normal status of the arc suppression coil module to the integrated automation system through the serial communication interface of the monitoring host Operating status information as well as grounding status information.