CN207181589U - It is a kind of to be used for the device being monitored powered to deformation of transformer winding - Google Patents

Abstract

The utility model discloses a device for monitoring deformation and electrification of transformer windings. The device includes: an excitation source, which is used to receive a frequency-sweeping sinusoidal voltage signal output by a main controller, and output it to the excitation signal after power amplification The injection sensor; the excitation signal injection sensor is used to generate an induced potential on the transformer winding through magnetic field coupling according to the frequency-sweeping sinusoidal voltage signal; the response signal measurement sensor is used to measure the induced potential at both ends of the transformer winding The generated frequency sweep response current signal, and output the response current signal to the main controller; the main controller is used to obtain the frequency response curve of the transformer winding according to the frequency sweep sinusoidal voltage signal and the corresponding sweep frequency response current signal The shape determination unit is used to diagnose the frequency response curve based on the diagnostic method in the DLT911-2004 standard, and determine the deformation of the transformer winding; the alarm unit is used to issue an alarm according to the deformation of the transformer winding.

Description

A device for monitoring transformer winding deformation and electrification

technical field

The utility model relates to the technical field of transformers, and more particularly relates to a device for monitoring deformation and charging of transformer windings.

Background technique

Transformer winding deformation refers to the irreversible change in the size or shape of the winding under the action of electrodynamic force and mechanical force. It includes changes in axial and radial dimensions, body displacement, winding twist, bulge and inter-turn short circuit, etc. In addition, the winding deformation also has a cumulative effect, that is, after being subjected to a short-circuit current impact, the transformer winding is not damaged immediately, and only has a small permanent deformation, but it leads to a decrease in its insulation performance and mechanical performance. When the next short-circuit current impacts, the winding deformation will be aggravated, and a vicious circle will appear. Therefore, a transformer with deformed windings is a hidden danger of accidents. If a large overcurrent is encountered during operation, major accidents such as transformer damage may occur. At present, the transformer winding deformation fault has become one of the main faults of the transformer. Therefore, it is necessary to detect the deformation of the transformer winding and diagnose its deformation degree, and carry out preventive maintenance of the transformer accordingly.

For this reason, it is necessary to research and formulate scientific and feasible detection methods to realize the detection of transformer winding deformation. Many countries in the world have invested a lot of energy in the research of transformer winding deformation detection methods. Offline detection. Among them, the most commonly used winding deformation monitoring method is the frequency response method. After the transformer winding is deformed, parameters such as inductance, capacitance to ground, and interturn capacitance of the winding will change. The working principle of the frequency response method is to reflect the changes in the distributed inductance and distributed capacitance of the winding through the frequency response curve of the winding, and then judge whether the winding is deformed. Under the action of higher frequency voltage, each winding of the transformer can be regarded as a passive linear dual-port network composed of distributed parameters such as linear resistance, inductance (mutual inductance), and capacitance, and its internal characteristics can be determined by the transfer function H( jω) description. If the winding is deformed, the distributed inductance, capacitance and other parameters inside the winding will inevitably change, resulting in changes in the zero and pole points of the equivalent network transfer function H(jω), which will change the frequency response characteristics of the network. The frequency band range involved in the frequency response method is specified in my country's industry standard DL/T911 as 1 kHz to 1000 kHz. Some scholars also believe that the lower limit frequency of the frequency response method can be extended to 10Hz, and the upper limit frequency can be extended to 10MHz. The equivalent model of the transformer winding and the corresponding basic measurement circuit can be expressed as shown in Figure 1: where L represents the inductance between the coil cakes, K represents the longitudinal (inter-cake or inter-turn) capacitance between the coils, and C represents the capacitance of the coil to ground. Applying the frequency response method to measure the transformer winding can obtain a set of corresponding values of frequency and response, that is, the ratio of the voltage at the output terminal to the power supply terminal, usually expressed in logarithmic form:

H(ω)＝20log[|V ₀ (jω)|/|V _i (jω)|] (1)

Among them, │Vo(jω)│ and │Vi(jω)│ represent the peak value or effective value of the output voltage and the input power supply voltage when the frequency is ω. When these corresponding values are plotted on the coordinate axis with ω as the horizontal axis and H(ω) as the vertical axis, a curve will be obtained, which we call the frequency response curve.

The industry standard DLT911-2004 clearly proposes a diagnostic method for detecting transformer winding deformation using the frequency response method. Using the frequency response analysis method to judge the deformation of transformer windings is mainly to compare the amplitude-frequency response characteristics of the windings vertically or horizontally, and to comprehensively consider factors such as the short-circuit impact of the transformer, transformer structure, electrical tests, and analysis of dissolved gases in oil. According to the size of the correlation coefficient, the change of the amplitude-frequency response characteristics of the transformer winding can be reflected more intuitively, and it can usually be used as an auxiliary means to judge the deformation of the transformer winding.

The existing transformer winding deformation monitoring device based on the frequency response method is only suitable for offline outage transformers. The transformer needs to be disconnected from the grid, and a frequency sweep excitation signal (sinusoidal voltage with gradually increasing or decreasing frequency) is injected from one end of the transformer winding. signal), measure the response signal from the other end of the winding; then by calculating the ratio of the amplitude of the response signal to the excitation signal (that is, one of the transfer functions), the frequency response curve is obtained; finally, through horizontal comparison, vertical comparison or Methods such as peak and valley frequency diagnosis can be used to judge whether there is deformation in the transformer winding.

The main controller of the existing transformer winding deformation monitoring device based on the frequency response method is a large instrument instead of an integrated circuit chip. The typical wiring mode of the monitoring device is shown in Figure 2. The winding deformation tester generates a sine frequency sweep excitation voltage, which is applied to the neutral point of the transformer winding; the instrument simultaneously monitors the amplitude of the applied excitation voltage through the input measurement impedance; the winding deformation The tester detects the response voltage signal of the excitation voltage at the high-voltage outlet end of the transformer winding through the output measurement impedance; the winding deformation tester has only one response signal measurement channel, and can only detect one winding at a time, as shown in Figure 2. Fig. 2 shows the connection mode of the existing transformer winding deformation monitoring device. For the three-phase winding of the transformer, it is necessary to change the wiring and measure sequentially, which is time-consuming and laborious.

In recent years, some scholars have proposed online application of frequency response method. The main problem with online application of the frequency response method is the filling of the signal and the elimination of external equipment. Foreign scholars proposed to inject the frequency sweep signal from the lead-out line of the bushing end screen, and gave the circuit and the corresponding protection impedance composition of the voltage-type excitation source connected to the bushing end screen. However, the end screen of the transformer bushing running online must be grounded. For transformers operating on-line, it is almost impossible to inject a frequency sweep signal from the end screen of the bushing. In addition, no research results have been seen on how to eliminate the influence of external devices.

Therefore, a transformer winding deformation monitoring device is needed to realize online monitoring of transformer winding deformation.

Contents of the invention

The utility model provides a device for monitoring the deformation and electrification of the transformer winding to solve the problem of how to monitor the deformation of the transformer winding on-line.

In order to solve the above problems, the utility model provides a device for monitoring deformation and charging of transformer windings. The device includes: an excitation source, an excitation signal injection sensor, a response signal measurement sensor, a main controller, and a deformation determination unit and alarm unit,

The excitation source is used to receive the frequency-sweeping sinusoidal voltage signal output by the main controller, amplify the power of the frequency-sweeping sinusoidal voltage signal, and then output it to the excitation signal and inject it into the sensor;

The excitation signal is injected into the sensor, connected to the excitation source through a signal cable, and used to generate an induced potential on the transformer winding through magnetic field coupling according to the frequency-sweeping sinusoidal voltage signal;

The response signal measurement sensor is connected to the main controller through a signal cable, and is used to measure the sweep frequency response current signal generated by the induced potential at both ends of the transformer winding, and output the response current signal to the main controller;

The main controller is used to obtain the frequency response curve of the transformer winding according to the frequency-sweeping sinusoidal voltage signal and the corresponding frequency-sweeping response current signal;

The deformation determination unit is used to diagnose the frequency response curve based on the diagnostic method in the DLT911-2004 standard, and determine the deformation of the transformer winding;

The alarm unit is used to issue an alarm according to the deformation of the transformer winding.

Preferably, the frequency of the frequency-sweeping sinusoidal voltage signal is 1kHz-1MHz, and the step size is 1kHz; the frequency and waveform of the signal before and after power amplification are consistent, and the amplitude of the frequency-sweeping sinusoidal voltage signal after amplification is 60V, and the power is up to 200W.

Preferably, the excitation signal injection sensor is a Rogowski coil with a magnetic core, and the frequency-swept sinusoidal voltage signal is applied to both ends of the coil of the excitation signal injection sensor through a signal cable.

Preferably, the response signal measuring sensor is a Rogowski coil current sensor with a magnetic core.

Preferably,

When the excitation signal injection sensor is set outside the root of the bushing of the neutral point lead-out line of the transformer winding, the response signal measuring sensor is set outside the root of the high-voltage lead-out line of the transformer winding to measure the high-voltage lead-out line of the transformer winding. The sweep frequency response current signal;

When the excitation signal injection sensor is placed outside the root of the high-voltage outlet bushing of the transformer winding, the response signal measurement sensor is placed outside the root of the neutral point bushing of the transformer winding and/or placed at the root of the high-voltage outlet bushing of the transformer winding Outside, it is used to measure the sweep frequency response current signal on the neutral ground wire of the transformer winding.

Preferably, there are at least four response signal measuring sensors, at least one of which is set outside the root of the neutral point bushing of the transformer winding, and at least three are set outside the root of the high voltage lead wire bushing of the three-phase winding of the transformer to measure the high voltage of the transformer winding. The sweep frequency response current signal on the lead line.

Preferably, the main controller further includes: an analog-to-digital conversion module and a signal calculation module,

The analog-to-digital conversion module is used to convert the frequency-swept sinusoidal voltage signal and the corresponding frequency-sweep response current signal into a frequency-sweep sinusoidal voltage digital signal and a corresponding frequency-sweep response current digital signal;

The signal calculation module is used to calculate the frequency spectrum after filtering the frequency-sweeping sinusoidal voltage digital signal and the corresponding frequency-sweeping response current digital signal.

Preferably, wherein the main controller also includes: a network communication module,

The network communication module is used to transmit the frequency response curve data to an external device through a network interface.

In the scheme of the utility model, the injection of the excitation signal and the measurement of the response signal are all carried out through the Rogowski coil, which does not need to be directly connected with the transformer winding, so that the high voltage winding of the transformer is in the operating state of high voltage and high current, and the winding is deformed The monitoring device is in a low potential state, which ensures that the proposed winding deformation monitoring device can be applied to power transformers running on-line, and then realizes real-time detection of winding deformation of transformers running on-line. For the offline outage power transformer, simply ground the two ends of the transformer winding to provide a loop for the current, so as to monitor the deformation of the offline outage power transformer winding.

Description of drawings

A more complete understanding of the exemplary embodiments of the present invention may be obtained by referring to the following drawings:

Fig. 1 is a schematic diagram of an n-order concentrated parameter winding model of a transformer winding and a frequency response measurement circuit according to an embodiment of the present invention;

Fig. 2 is the internal wiring diagram of the existing transformer winding deformation monitoring device;

Fig. 3 is a schematic structural diagram of a device 300 for monitoring transformer winding deformation and electrification according to an embodiment of the present invention;

Fig. 4 is an example diagram of a device for monitoring transformer winding deformation and electrification according to an embodiment of the present invention;

Fig. 5 is a schematic diagram of an excitation signal injected into a sensor according to an embodiment of the present invention;

Fig. 6 is a schematic diagram of the frequency-sweeping signal injection principle for online diagnosis of transformer winding deformation based on frequency response characteristics according to an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present invention are now described with reference to the accompanying drawings; however, the present invention may be implemented in many different forms and are not limited to the embodiments described herein, which are provided for exhaustive and complete The utility model is disclosed and fully conveys the scope of the utility model to those skilled in the art. The terms used in the exemplary embodiments shown in the drawings do not limit the present invention. In the figures, the same units/elements are given the same reference numerals.

Unless otherwise specified, the terms (including scientific and technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it can be understood that terms defined by commonly used dictionaries should be understood to have consistent meanings in the context of their related fields, and should not be understood as idealized or overly formal meanings.

Fig. 3 is a schematic structural diagram of a device 300 for monitoring deformation and electrification of transformer windings according to an embodiment of the present utility model.

As shown in Figure 3, the injection of the excitation signal and the measurement of the response signal of the device 300 for monitoring the deformation and charging of the transformer winding do not need to have a direct electrical connection with the transformer winding, so that the high voltage winding of the transformer can be kept at a high voltage. voltage and high current operating state, and the winding deformation monitoring device is in a low potential state, therefore, the winding deformation monitoring device in the embodiment of the utility model can be applied to power transformers running online, and then realize the monitoring of winding deformation of transformers running online Real-time detection.

The real-time winding deformation monitoring device of the utility model can be applied to power transformers that are offline and out of service, as long as the two ends of the transformer winding are simply grounded to provide a circuit for the current.

The device 300 for monitoring transformer winding deformation and electrification may include: an excitation source 301 , an excitation signal injection sensor 302 , a response signal measurement sensor 303 , a main controller 304 , a deformation determination unit 305 and an alarm unit 306 .

Preferably, the excitation source 301 is configured to receive the frequency-sweeping sinusoidal voltage signal output by the main controller, amplify the power of the frequency-sweeping sinusoidal voltage signal, and then output the excitation signal to inject the sensor. Preferably, the excitation signal injection sensor is a Rogowski coil with a magnetic core, and the frequency-swept sinusoidal voltage signal is applied to both ends of the coil of the excitation signal injection sensor through a signal cable. Preferably, the frequency of the frequency-sweeping sinusoidal voltage signal is 1kHz-1MHz, and the step size is 1kHz; the frequency and waveform of the signal before and after power amplification are consistent, and the amplitude of the frequency-sweeping sinusoidal voltage signal after amplification is 60V, and the power is up to 200W.

Preferably, the excitation signal is injected into the sensor 302 and connected to the excitation source through a signal cable, and is used to generate an induced potential on the transformer winding through magnetic field coupling according to the frequency-swept sinusoidal voltage signal.

Preferably, the response signal measurement sensor 303 is connected to the main controller through a signal cable, and is used to measure the frequency sweep response current signal generated by the induced potential at both ends of the transformer winding, and output the response current signal to main controller.

Preferably, when the excitation signal injection sensor is placed outside the root of the bushing of the neutral point lead wire of the transformer winding, the response signal measurement sensor is placed outside the root of the high voltage lead wire bushing of the transformer winding to measure the high voltage of the transformer winding. Sweep frequency response current signal on the lead-out line;

When the excitation signal injection sensor is placed outside the root of the high-voltage outlet bushing of the transformer winding, the response signal measurement sensor is placed outside the root of the neutral point bushing of the transformer winding and/or placed at the root of the high-voltage outlet bushing of the transformer winding Outside, it is used to measure the sweep frequency response current signal on the neutral ground wire of the transformer winding.

Preferably, the main controller 304 is configured to obtain the frequency response curve of the transformer winding according to the frequency-sweeping sinusoidal voltage signal and the corresponding frequency-sweeping response current signal.

Preferably, the main controller further includes: an analog-to-digital conversion module and a signal calculation module,

The analog-to-digital conversion module is used to convert the frequency-swept sinusoidal voltage signal and the corresponding frequency-sweep response current signal into a frequency-sweep sinusoidal voltage digital signal and a corresponding frequency-sweep response current digital signal;

The signal calculation module is used to calculate the frequency spectrum after filtering the frequency-sweeping sinusoidal voltage digital signal and the corresponding frequency-sweeping response current digital signal.

Preferably, wherein the main controller also includes: a network communication module,

The network communication module is used to transmit the frequency response curve data to an external device through a network interface;

Preferably, the deformation determination unit 305 is configured to diagnose the frequency response curve based on the diagnosis method in the DLT911-2004 standard, and determine the deformation of the transformer winding.

Preferably, the alarm unit 306 is configured to issue an alarm according to the deformation of the transformer winding

Fig. 4 is an example diagram of a device for monitoring deformation and electrification of transformer windings according to an embodiment of the present utility model. As shown in Figure 4, in the embodiment of the utility model, the device includes: an excitation source (1), an excitation signal injection sensor (2), a response signal measurement sensor (3), a main controller (4), a signal Cable (5), signal cable (6), deformation determination unit (13) and alarm unit (14).

The output frequency of the main controller (4) gradually increases from 1kHz to 1MHz, and the frequency-sweeping sinusoidal voltage signal with a step size of 1kHz is received by the excitation source (1) and power is amplified; the frequency-sweeping sinusoidal voltage signal output by the excitation source (1) The frequency and waveform of the voltage signal remain unchanged from the input signal from the main controller (4), while the amplitude can reach 60V and the power can reach 200W; the high-power sweeping sinusoidal voltage signal output by the excitation source (1) passes through the signal cable (5) Applied on the excitation signal injection sensor (2); the excitation signal injection sensor (2) generates an induced potential on the transformer winding through magnetic field coupling; the response signal measurement sensor (3) measures the induced potential at both ends of the transformer winding The generated current signal; the output signal of the response signal measuring sensor (3) enters the main controller (4) through the signal cable (6), and is collected and processed by the main controller (4); the main controller (4) synchronously outputs the frequency sweep The sinusoidal voltage signal is collected and the output signal of the response signal measuring sensor (3) is filtered and processed to obtain the frequency response curve of the winding, and the frequency response curve data is transmitted to the computer through the network communication interface for display and storage. A deformation determination unit (13), configured to diagnose the frequency response curve based on the diagnosis method in the DLT911-2004 standard, and determine the deformation of the transformer winding. The alarm unit (14) is used to issue an alarm according to the deformation of the transformer winding. Remind maintenance personnel to carry out timely maintenance.

The main controller is composed of a frequency sweep signal generation module (7), four analog-to-digital conversion modules (8), four digital filtering and frequency calculation modules (9), a correlation coefficient calculation module (12), and a network communication module (10) , A circuit system composed of a crystal oscillator circuit module (11). The realization technology of the circuits of these modules is very mature, can be used directly, and is easy to realize. Wherein, the frequency-sweeping signal generation module is used to output the frequency-sweeping sinusoidal voltage signal; the analog-to-digital conversion module is respectively used to convert the output signal of the collected frequency-sweeping sinusoidal voltage signal and the collected response signal measuring sensor into a digital signal; The digital filtering and frequency calculation module is used to perform filter processing and frequency spectrum calculation on the digital signal corresponding to the frequency-sweeping sinusoidal voltage signal and the collected response signal measurement sensor output signal; the correlation coefficient calculation module is used to calculate different The correlation coefficient of the two frequency response curves of time; the network communication module is used to transmit the data of the frequency response curve to the external device for display and storage through the network communication interface; the crystal oscillator circuit module is used to provide the main control the clock frequency required by the device.

Fig. 5 is a schematic diagram of an excitation signal injected into a sensor according to an embodiment of the present invention. As shown in Figure 5, the excitation signal injection sensor (2) is a Rogowski coil with a magnetic core, which is placed outside the root of the bushing of the neutral point of the transformer winding; the high-power output of the excitation source (1) The frequency-sweeping sinusoidal voltage signal is applied to both ends of the coil of the excitation signal injection sensor (2) through the signal cable (5). The response signal measuring sensor (3) is a Rogowski coil type current sensor with a magnetic core, and there are four of them. Among them, three are placed outside the root of the bushing of the high-voltage lead-out wires of the transformer A-phase winding, B-phase winding and C-phase winding, and are used to measure the sweep frequency response current signal on the high-voltage lead-out wire of the winding, and the other It is only used to be placed outside the root of the neutral point bushing of the transformer winding to measure the sweep frequency response current signal on the neutral point grounding wire of the winding.

Fig. 6 is a schematic diagram of the frequency-sweeping signal injection principle for online diagnosis of transformer winding deformation based on frequency response characteristics according to an embodiment of the present invention. The response signal measurement sensor (3) uses a Rogowski coil type current sensor with a magnetic core to measure the current signal, and its principle and method are very mature. The principle of the excitation signal injection sensor (2) using the Rogowski coil to couple the voltage and current signals to the conductor is shown in Figure 6: ZS indicates the external device that is directly electrically connected to the high-voltage lead-out line of the transformer when monitoring the transformer running online impedance. There is magnetic field coupling (mutual inductance) between the coil of the sensor (2) and the lead-out line of the neutral line of the transformer winding, which is equivalent to a transformer with n turns on the primary side and 1 turn on the secondary side. In practical applications, the Rogowski coil uses a high-permeability magnetic core to enhance the coupling effect and inject stronger signals. incentive source As a voltage source, a current is generated in the coil through the current limiting resistor R0 The generated magnetic field induces an electromotive force on the secondary side (ie, the high-voltage lead-out wire of the winding) with current and The relationship between them can be expressed by the transfer function of the Rogowski coil (2), which is a definite relationship that can be measured in advance. The calculation formula of the transfer function (2) is:

Among them, L is the inductance of the coil; M is the mutual inductance between the coil and the high-voltage lead-out wire of the winding.

The invention has been described with reference to a small number of embodiments. However, as is well known to those skilled in the art, as defined by the appended patent claims, other embodiments than those disclosed above equally fall within the scope of the present invention.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a/the/the [means, component, etc.]" are openly construed to mean at least one instance of said means, component, etc., unless expressly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Claims (8)

1. a kind of be used for the device being monitored powered to deformation of transformer winding, it is characterised in that described device includes：Excitation Source, pumping signal injection sensor, response signal measurement sensor and main controller, deformation determining unit and alarm unit,

The driving source, for receiving the swept-sine voltage signal of main controller output, by the swept-sine voltage signal Output to pumping signal injects sensor after power carries out power amplification；

The pumping signal injects sensor, is connected with the driving source by signal cable, for according to the frequency sweep just String voltage signal, produces induced potential by way of magnetic coupling in Transformer Winding；

The response signal measurement sensor, it is connected with main controller by signal cable, is existed for measuring the induced potential Frequency sweep response current signal caused by Transformer Winding both ends, and by the response current signal output to main controller；

The main controller, for according to the swept-sine voltage signal and corresponding frequency sweep response current signal acquisition transformer The frequency response curve of winding；

The deformation determining unit, for being entered based on the diagnostic method in DLT911-2004 standards to the frequency response curve Row diagnosis, determine the deformation of Transformer Winding；

The alarm unit, alarm is sent for the deformation according to Transformer Winding.

2. device according to claim 1, it is characterised in that the frequency of the swept-sine voltage signal is 1kHz- 1MHz, step-length 1kHz；The frequency of signal is consistent with waveform before and after power amplification, the width of the swept-sine voltage signal after amplification It is up to 200W to be worth for 60V, power.

3. device according to claim 1, it is characterised in that the pumping signal injection sensor is sieve with magnetic core Fruit Paderewski coil, the swept-sine voltage signal are applied to the coil two of pumping signal injection sensor by signal cable End.

4. device according to claim 1, it is characterised in that the response signal measurement sensor is sieve with magnetic core Fruit Paderewski coil form current sensor.

5. device according to claim 1, it is characterised in that

When the pumping signal injects sensor sleeve outside Transformer Winding neutral lead ferrule boot, the response Signal measurement sensor sleeve is drawn outside the high-voltage leading-out wire ferrule boot of Transformer Winding for measuring transformer winding high voltage Frequency sweep response current signal in outlet；

When the pumping signal injects sensor sleeve outside Transformer Winding high-voltage terminal ferrule boot, the response signal Measurement sensor is enclosed on outside Transformer Winding neutral bushing root and/or is enclosed on the high-voltage leading-out wire sleeve pipe of Transformer Winding Outside root, for the frequency sweep response current signal on measuring transformer winding neutral ground line.

6. device according to claim 1, it is characterised in that the response signal measurement sensor at least 4, at least 1 Only it is enclosed on outside Transformer Winding neutral bushing root, at least 3 high-voltage leading-out wire sleeve pipes for being enclosed on Three-Phase Transformer winding Outside root, the frequency sweep response current signal on measuring transformer winding high voltage lead-out wire.

7. device according to claim 1, it is characterised in that the main controller also includes：Analog-to-digital conversion module and signal Computing module,

The analog-to-digital conversion module, for the swept-sine voltage signal and corresponding frequency sweep response current signal to be turned respectively It is changed to swept-sine voltage digital signal and corresponding frequency sweep response current data signal；

The signal of change module, for the swept-sine voltage digital signal and corresponding frequency sweep response current numeral letter Frequency spectrum is calculated after number being filtered processing.

8. device according to claim 1, it is characterised in that the main controller also includes：Network communication module,

The network communication module, for the frequency response curve data to be sent into external equipment by network interface.