Intelligent ultrahigh frequency cable partial discharge monitoring device

Abstract

The utility model discloses an intelligent ultrahigh frequency cable partial discharge monitoring device, and belongs to the technical field of cable partial discharge monitoring. The system mainly comprises an MCU main control chip, a power supply module unit, an MCU main control chip minimum working unit, a high-frequency signal acquisition unit, an amplification circuit unit, an alarm module unit, an upper decision unit, a communication module unit and a background data processing center. The output end of the amplification circuit unit is electrically connected with the first-stage filter; the first-stage filter is used for filtering the electric signal with the frequency value smaller than f1; the electric signal processed by the primary filter is electrically connected with the input end of the low-pass filter, and the output end of the low-pass filter outputs a power-on electric signal to the MCU main control chip; and the cut-off frequency of the low-pass filter is f2. According to the utility model, the ultrahigh frequency sensor is high in model selection flexibility, high in monitoring precision, simple and reliable in circuit design, low in cost, strong in noise reduction capability and strong in anti-interference performance.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the cable partial discharge monitoring technical field, concretely, especially, it is especially related to a kind of intelligent ultra-high frequency cable partial discharge monitoring device with high flexibility of ultra-high frequency sensor selection, high monitoring precision, simple and reliable circuit design, low cost, strong noise reduction ability and strong anti-interference. BACKGROUND

[0002] Cable, as the key component of power transmission, its fault is often accompanied by temperature rise, flashover phenomenon and other signs.However, temperature detection has hysteresis, so it is usually only one of the auxiliary criteria.In contrast, flashover phenomenon is monitored with emphasis due to its immediacy.Studies have shown that the frequency range of flashover signal is between 100MHz and 1.5GHz.

[0003] The Chinese patent with patent application number 2020114182960, application date December 7, 2020 and invention name "Cable Partial Discharge Online Monitoring Device Based on Ultra-High Frequency" discloses a technical solution mainly including a sampling controller, an ultra-high frequency sensor and a noise sensor.The sampling controller includes an embedded MCU, a power module, a 485 communication module and two signal conditioning modules.The embedded MCU is connected to the two signal conditioning modules and the 485 communication module.The power module is used to power each module.The output end of the ultra-high frequency sensor is connected to one signal conditioning module of the sampling controller through a radio frequency coaxial connection line.The output end of the noise sensor is connected to the other signal conditioning module of the sampling controller through a radio frequency coaxial connection line.The ultra-high frequency sensor module has a working frequency of 300-1500MHz.The ultra-high frequency sensor collects ultra-high frequency signals, which are converted into pulse signals through logarithmic detection processing, and then the pulse signal duration is increased through the voltage holding function of LM7121.

[0004] Therefore, the conventional ultrahigh frequency cable partial discharge monitoring device depends on the parameter selection of the ultrahigh frequency sensor in the frequency screening of the flashover signal. However, different application scenarios have different requirements for frequency screening, and it is difficult to find a sensor that can completely adapt to the frequency band. Specifically, on the one hand, if an ultrahigh frequency sensor with wide parameters is used, a large number of signals other than flashover signals may be mixed in; on the other hand, if an ultrahigh frequency sensor with too narrow parameters is used, part of the flashover signals may be missed, so that the specific frequency band cannot be screened accurately. Even if the ultrahigh frequency sensor is selected strictly according to the required frequency band, a new problem will be encountered; that is, such a specialized ultrahigh frequency sensor not only has high cost, but also is difficult to find a suitable product in the market. In addition, the electromagnetic environment where the monitoring device is located is complex, and if the frequency band screening is completely dependent on the ultrahigh frequency sensor, the noise reduction and anti-interference capabilities of the entire circuit will be relatively weak, thereby making it difficult to effectively guarantee the accuracy of the flashover signal monitoring. Practical new type content

[0005] The utility model discloses a kind of intelligent ultrahigh frequency cable partial discharge monitoring devices, which is high in flexibility of ultrahigh frequency sensor selection, high in monitoring precision, simple and reliable in circuit design, low in cost, strong in noise reduction capability and strong in anti-interference.

[0006] The utility model is realized through the following technical schemes:

[0007] An intelligent ultrahigh frequency cable partial discharge monitoring device includes an MCU main control chip, a minimum working unit of the MCU main control chip, and a power module unit providing a working power supply. A high-frequency signal acquisition unit for electrical connection with an ultrahigh frequency sensor is electrically connected to the input end of the MCU main control chip. The high-frequency signal acquisition unit converts high-frequency electromagnetic wave signals into voltage signals and inputs the converted signals to an amplification circuit unit for amplification processing. The output end of the amplification circuit unit is electrically connected to a first-order filter through a high-speed switching diode VD1. The first-order filter includes a parallelly connected resistor R14 and a capacitor C8, and is used to filter out electrical signals with a frequency value less than f1. The electrical signals processed by the first-order filter are electrically connected to the input end of a low-pass filter through an impedance matching resistor R8. The output end of the low-pass filter outputs band-pass electrical signals to the MCU main control chip through an impedance matching resistor R9 and a diode VD2. The cutoff frequency of the low-pass filter is f2, and the low-pass filter includes a parallelly connected capacitor C5 and resistor R11. The output end of the MCU main control chip is electrically connected to an alarm module unit, and the output end of the alarm module unit transmits alarm information to an upper decision unit.

[0008] The MCU main control chip is also bidirectionally connected to a background data processing center through a communication module unit.

[0009] Preferably, the value of f1 is 100MHz and the value of f2 is 1500MHz.

[0010] Preferably, a three-stage filter is electrically connected between the diode VD2 and the MCU main control chip; the three-stage filter includes a resistor R12 and a capacitor C7 connected in parallel; the cathode of the diode VD2 is electrically connected to one end of the resistor R12, one end of the capacitor C7, and the MCU main control chip through the impedance matching resistor R10; the other end of the resistor R12 and the other end of the capacitor C7 are both electrically connected to the ground terminal AGND.

[0011] Preferably, the input terminal of the MCU main control chip is also electrically connected to a temperature and pressure environmental parameter monitoring module unit.

[0012] Preferably, the temperature and pressure environmental parameter monitoring module unit includes a CN2 connector; pins 1 and 2 of the CN2 connector are used to connect a temperature and humidity sensor and form a circuit with the MCU main control chip; pins 3 and 4 of the CN2 connector are used to connect a pressure sensor and form a circuit with the MCU main control chip.

[0013] Preferably, the high-frequency signal acquisition unit includes an RF pickup chip U2 and an external interface PEX for connecting an ultra-high frequency sensor. Pins 2 and 3 of the external interface PEX are electrically connected to the ground terminal AGND. Pin 1 of the external interface PEX is electrically connected to the ground terminal AGND via an RF coupling capacitor C6, a noise reduction resistor R16, an RF coupling capacitor C9, and a symmetrical resistor R15. The two ends of the resistor R16 are electrically connected to pins 2 and 3 of the RF pickup chip U2, respectively. Pin 1 of the RF pickup chip U2 is electrically connected to one end of a filter capacitor C4, the positive terminal of an electrolytic capacitor E2, and one end of a resistor R2. The other end of the resistor R2 is electrically connected to the power supply terminal VCC-A5V. The other end of the filter capacitor C4, the positive terminal of the electrolytic capacitor E2, and the positive terminal of the electrolytic capacitor E2 are also electrically connected. The negative terminal of electrolytic capacitor E2 is electrically connected to ground AGND; pin 4 of RF pickup chip U2 is electrically connected to one end of filter capacitor C10, the positive terminal of electrolytic capacitor E3, and one end of resistor R17. The other end of resistor R17 is electrically connected to power supply VCC-A5V. The negative terminal of electrolytic capacitor E3 and the other end of filter capacitor C10 are both electrically connected to ground AGND; pins 5 and 6 of RF pickup chip U2 are both electrically connected to ground AGND; pin 7 of RF pickup chip U2 is electrically connected to the input terminal of the amplifier circuit unit through feedback resistor R13 and impedance matching resistor R5; pin 8 of RF pickup chip U2 is electrically connected between feedback resistor R13 and impedance matching resistor R5.

[0014] Preferably, the amplification circuit unit comprises an amplifier U1, the 3-pin of the amplifier U1 is electrically connected with the output end of the high-frequency signal acquisition unit; the 4-pin of the amplifier U1 is electrically connected with the ground end AGND; the 2-pin of the amplifier U1 is electrically connected between the proportional resistor R3 and the proportional resistor R4, the other end of the proportional resistor R3 is electrically connected with the ground end AGND, the other end of the proportional resistor R4 is electrically connected with the 6-pin of the amplifier U1 on one hand through the filter capacitor C1 and the ground end AGND, and on the other hand through the impedance matching resistor R6 and the impedance matching resistor R7 and the high-speed switching diode VD1; the 7-pin of the amplifier U1 is electrically connected with the ground end AGND through the capacitor C3, is electrically connected with the ground end AGND through the capacitor C2, is electrically connected with the grounding point AGND through the electrolytic capacitor E1, and is electrically connected with the power supply end VCC-A5V through the resistor R1.

[0015] Preferably, the model of the MCU master control chip is GD32F303RCT6; the input voltage of the power module unit is 12V direct current, and the output 3.3V direct current voltage is taken as the power supply end 3V3, the output 5V direct current voltage for digital circuit is taken as the power supply end VCC-5V, and the output 5V voltage for analog circuit is taken as the power supply end VCC-A5V.

[0016] Preferably, the alarm module unit comprises a two-way output relay RELAY1, the 1-pin of the two-way output relay RELAY1 is electrically connected with the power supply end VCC-5V, the 4-pin and the 5-pin of the two-way output relay RELAY1 are combined into an alarm output port for being electrically connected with the upper decision unit; the 8-pin of the two-way output relay RELAY1 is electrically connected with the ground end GND through the resistor R35 and the light-emitting diode D3; the 9-pin of the two-way output relay RELAY1 is connected with the power supply end 3V3; the 12-pin of the two-way output relay RELAY1 is electrically connected with the power supply end VCC-5V through the diode VD3 on one hand, and is electrically connected with the collector of the triode Q1 on the other hand; the base of the triode Q1 is electrically connected with the MCU master control chip through the resistor R21, the node between the resistor R21 and the triode Q1 is also electrically connected with the ground end GND through the resistor R22, and the emitter of the triode Q1 is electrically connected with the ground end GND.

[0017] Preferably, the communication module unit comprises a communication signal conversion chip U8; the 1 pin and the 4 pin of the communication signal conversion chip U8 are serial signal input and output ports and are electrically connected with the MCU master control chip; the 2 pin and the 3 pin of the communication signal conversion chip U8 are direction control pins and are electrically connected with the MCU master control chip; the 5 pin of the communication signal conversion chip U8 is electrically connected with the ground end GND; the 6 pin and the 7 pin of the communication signal conversion chip U8 are differential input and output ports, the 6 pin and the 7 pin of the communication signal conversion chip U8 are electrically connected with the resistance R31, the 6 pin of the communication signal conversion chip U8 is electrically connected with the power supply end 3V3 through the resistance R32 on one hand and is electrically connected with the background data processing center on the other hand; the 7 pin of the communication signal conversion chip U8 is electrically connected with the ground end GND through the resistance R30 on one hand and is electrically connected with the background data processing center on the other hand.

[0018] Compared with the prior art, the utility model has the advantages that:

[0019] 1. The utility model discloses a high-frequency sensor selection flexibility is high, and the monitoring precision is high, and the over-reliance of traditional flashover signal monitoring device on the parameter selection of high-frequency sensor is got rid of, and the problem that the sensor that completely adapts frequency band is difficult to find under different application scenes is overcome. Whether the demand of wide frequency band coverage or narrowband accurate screening is faced, the utility model can be flexibly coped with, and the situation that a large number of non-flashover signals or flashover signals are mixed or missed due to improper sensor parameters no longer appears, accurate and efficient screening for specific frequency band is truly realized, and the monitoring precision of the device is greatly improved;

[0020] 2. The utility model discloses that the high-frequency sensor of low price on the market is selected, and the selection flexibility is flexible, and the types and quantity of components applied to the whole circuit are few, and the circuit design is simple and reliable, and the production cost is low;

[0021] 3. The utility model discloses strong noise reduction ability, and strong anti-interference, can effectively filter electromagnetic noise and interference signal, makes the accuracy of flashover signal monitoring has been strongly guaranteed, provides more accurate, reliable data support for high-frequency cable partial discharge monitoring, satisfies the requirement of high performance, high reliability of monitoring device under different scenes. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the circuit principle schematic drawing of the utility model embodiment 1, embodiment 2.

[0023] Figure 2 It is the circuit principle schematic drawing of the utility model embodiment 4.

[0024] Figure 3 It is the circuit principle schematic drawing of the MCU master control chip and the minimum working unit circuit of the MCU master control chip.

[0025] Figure 4 This is a schematic diagram of the circuit principle of Embodiment 3 of this utility model. Figure 1 .

[0026] Figure 5 This is a schematic diagram of the circuit principle of Embodiment 3 of this utility model. Figure 2 .

[0027] Figure 6 This is a schematic diagram of the circuit principle of the temperature and pressure environmental parameter monitoring module unit of this utility model.

[0028] Figure 7 This is a schematic diagram of the alarm module unit circuit of this utility model.

[0029] Figure 8 This is a schematic diagram of the communication module unit circuit of this utility model.

[0030] In the diagram: 1. High-frequency signal acquisition unit; 2. Amplification circuit unit; 3. MCU main control chip; 4. Power supply module unit; 5. Alarm module unit; 6. Communication module unit; 7. Temperature and pressure environmental parameter monitoring module unit; 8. Upper-level decision-making unit; 9. Back-end data processing center. Detailed Implementation

[0031] To enable readers to better understand the design intent of this utility model, the technical solution described below is further described in conjunction with embodiments. It should be noted that directional terms that may appear in the following paragraphs, including but not limited to "up," "down," "left," "right," "front," and "back," are based on the visual orientation shown in the accompanying drawings and should not be considered as limitations on the scope of protection or technical solution of this utility model. Their purpose is solely to facilitate a better understanding of the technical solution described in this utility model by those skilled in the art.

[0032] In this specification, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] Example 1

[0034] like Figure 1As shown, an intelligent ultra-high frequency cable partial discharge monitoring device includes an MCU main control chip 3, a power module unit 4 for providing working power, and a minimum working unit of the MCU main control chip. A high-frequency signal acquisition unit 1 for electrical connection with an ultra-high frequency sensor is electrically connected to an input end of the MCU main control chip 3. A radio frequency pickup chip U2 of the high-frequency signal acquisition unit 1 converts a high-frequency electromagnetic wave signal into a voltage signal and inputs the converted signal to an amplification circuit unit 2 for amplification processing. An output end of the amplification circuit unit 2 is electrically connected to a first-order filter through a high-speed switching diode VD1. The first-order filter includes a resistor R14 and a capacitor C8 connected in parallel and is used to filter out electrical signals with a frequency value less than f1. The electrical signal processed by the first-order filter is electrically connected to an input end of a low-pass filter through an impedance matching resistor R8. An output end of the low-pass filter outputs a band-pass electrical signal to the MCU main control chip 3 through an impedance matching resistor R9 and a diode VD2. A cutoff frequency of the low-pass filter is f2. The low-pass filter includes a capacitor C5 and a resistor R11 connected in parallel. An output end of the MCU main control chip 3 is electrically connected to an alarm module unit 5. An output end of the alarm module unit 5 transmits alarm information to an upper decision unit 8. The MCU main control chip 3 is also bidirectionally connected to a background data processing center 9 through a communication module unit 6.

[0035] Specifically, an output end of the amplification circuit unit 2 is electrically connected to an anode end of the high-speed switching diode VD1. The high-speed switching diode VD1 is used to avoid reverse signal transmission. A cathode end of the high-speed switching diode VD1 is electrically connected to one end of the resistor R14 and the capacitor C8 and then electrically connected to one end of the impedance matching resistor R8. The other ends of the resistor R14 and the capacitor C8 are both electrically connected to a ground end AGND. The other end of the impedance matching resistor R8 is electrically connected to an input end of the low-pass filter. An output end of the low-pass filter is electrically connected to an anode end of the diode VD2 through the impedance matching resistor R9. A cathode end of the diode VD2 transmits a signal to the MCU main control chip 3. The diode VD2 functions as a one-way conduction to prevent the signal from returning. The first-order filter composed of the resistor R14 and the capacitor C8 filters out signals with a frequency value less than f1, i.e., signals with a frequency value less than f1 are inhibited from passing through. The cutoff frequency of the low-pass filter composed of the capacitor C5 and the resistor R11 is f2, i.e., signals with a frequency value greater than f2 cannot pass through the low-pass filter. Therefore, the embodiment can make electrical signals with a frequency between f1 and f2 pass through. The circuit from the high-speed switching diode VD1 to the diode VD2 forms a band-pass filter, which fixes the frequency range between f1 and f2. Further, the value of f1 is 100 MHz and the value of f2 is 1500 MHz. The embodiment can accurately screen out cable flashover signal bands.

[0036] As Figure 3As shown, the model of the MCU master control chip 3 in this embodiment is GD32F303RCT6. The minimum working unit of the MCU master control chip refers to a crystal oscillator circuit composed of the capacitor C18, the crystal oscillator Y1, the capacitor C24, the capacitor C25, the crystal oscillator Y2, the capacitor C26, and the like, and a reset circuit composed of the resistor R23, the button S2, the capacitor C17, and the like. The minimum working unit of the MCU master control chip is the minimum system that enables the MCU master control chip 3 to work.

[0037] The working principle of this embodiment is as follows: The radio frequency pickup chip U2 of the high-frequency signal acquisition unit 1 converts the high-frequency electromagnetic wave signal into a voltage signal, which is transmitted to the amplification circuit unit 2. The voltage signal is amplified by the amplification circuit unit 2 without loss, and the amplified signal is accurately screened by the band-pass filter to obtain the ultra-high frequency flashover signal of 100MHz-1500MHz. When the MCU master control chip 3 detects the flashover signal, the alarm module unit 5 will be driven to issue an alarm, such as signal light emission, siren, and the like. At the same time, the alarm module unit 5 will also provide the alarm information to the upper decision unit 8, such as accessing the integrated protection device for tripping operation, notifying the operation and maintenance personnel, and the like. The MCU master control chip 3 also communicates with the background data processing center 9 through the communication module unit 6. The communication is bidirectional communication. The MCU master control chip 3 reports the monitoring information to the background data processing center 9 in real time, and can also issue control instructions by operating the background data processing center 9.

[0038] The ultra-high frequency sensor of this embodiment has high flexibility in selection and high monitoring accuracy, breaks the excessive dependence of the traditional flashover signal monitoring device on the selection of the parameters of the ultra-high frequency sensor, and overcomes the problem that it is difficult to find a sensor that completely matches the frequency band in different application scenarios. Whether it is necessary to cover a wide frequency band or to accurately screen a narrow band, the utility model can flexibly cope with it. The situation that a large number of non-flashover signals are mixed or flashover signals are missed due to improper sensor parameters no longer occurs. The utility model truly realizes efficient screening of specific frequency bands, greatly improves the monitoring accuracy of the device, and meets the requirements of high performance and high reliability of the monitoring device in different scenarios.

[0039] Embodiment 2

[0040] On the basis of embodiment 1, the technical features involved in the embodiment and the functions and roles of the technical features in the utility model are further described in detail to help the skilled in the art fully understand the technical scheme of the utility model and reproduce it.

[0041] As shown in the embodiment, the embodiment further has a three-stage filter electrically connected between the diode VD2 and the MCU master control chip 3. Figure 1 The three-stage filter specifically includes a resistance R12 and a capacitor C7 connected in parallel; the cathode end of the diode VD2 is electrically connected with the MCU master control chip 3 through the impedance matching resistance R10, one end of the resistance R12, one end of the capacitor C7, and the ground end AGND; the other end of the resistance R12 and the other end of the capacitor C7 are both electrically connected with the ground end AGND. The three-stage filter further reduces the noise of the output signal, makes the band-pass signal transmitted to the MCU master control chip 3 more accurate, and further improves the anti-interference and noise reduction performance of the circuit.

[0042] Embodiment 3

[0043] On the basis of embodiment 1 or embodiment 2, the technical features involved in the embodiment and the functions and roles of the technical features in the utility model are further described in detail to help the skilled in the art fully understand the technical scheme of the utility model and reproduce it.

[0044] As shown in the embodiment, the embodiment further has a three-stage filter electrically connected between the diode VD2 and the MCU master control chip 3. Figures 4-5As shown, the high-frequency signal acquisition unit 1 of the embodiment further comprises an external plug-in interface PEX for plugging in the ultra-high frequency sensor, the 2-pin and 3-pin of the external plug-in interface PEX are electrically connected with the ground terminal AGND, the 1-pin of the external plug-in interface PEX is electrically connected with the ground terminal AGND through the radio frequency coupling capacitor C6, the noise reduction resistor R16, the radio frequency coupling capacitor C9 and the symmetric resistor R15, the two ends of the resistor R16 are electrically connected with the 2-pin and 3-pin of the radio frequency pickup chip U2 respectively; the model of the radio frequency pickup chip U2 of the embodiment is AD8313. The 1-pin of the radio frequency pickup chip U2 is electrically connected with one end of the filter capacitor C4, the positive terminal of the electrolytic capacitor E2 and one end of the resistor R2, the other end of the resistor R2 is electrically connected with the power terminal VCC-A5V, the other end of the filter capacitor C4 and the negative terminal of the electrolytic capacitor E2 are electrically connected with the ground terminal AGND; the 4-pin of the radio frequency pickup chip U2 is electrically connected with one end of the filter capacitor C10, the positive terminal of the electrolytic capacitor E3 and one end of the resistor R17, the other end of the resistor R17 is electrically connected with the power terminal VCC-A5V, the negative terminal of the electrolytic capacitor E3 and the other end of the filter capacitor C10 are electrically connected with the ground terminal AGND; the 5-pin and 6-pin of the radio frequency pickup chip U2 are electrically connected with the ground terminal AGND; the 7-pin of the radio frequency pickup chip U2 is electrically connected with the input terminal of the amplification circuit unit 2 through the feedback resistor R13 and the impedance matching resistor R5, the 8-pin of the radio frequency pickup chip U2 is electrically connected between the feedback resistor R13 and the impedance matching resistor R5. The radio frequency coupling capacitor C6 and the radio frequency coupling capacitor C9 couple the high-frequency signal sensed by the ultra-high frequency sensor to the input terminal of the radio frequency pickup chip U2 to block the direct current signal. The resistor R16 is a signal noise reduction resistor and also plays a role of resistance matching, reducing input noise and signal loss. The resistor R15 is a symmetric resistor with a resistance value of 0 ohm, which provides a reference level for the negative end of the high-frequency signal. The resistor R2 and the resistor R17 further filter the power entering the radio frequency pickup chip U2. The electrolytic capacitor E2, the filter capacitor C4, the electrolytic capacitor E3 and the filter capacitor C10 are filter capacitors, which further stabilize the voltage to enable the radio frequency pickup chip U2 to obtain stable and clean direct current voltage. The output terminal of the radio frequency pickup chip U2 is connected with the impedance matching resistor R5 and the feedback resistor R13, wherein the feedback resistor R13 is connected with the 7-pin of the radio frequency pickup chip U2 for feedback signal. Thus, the high-frequency signal is converted into a related voltage signal, and the signal is stable and clean.

[0045] The amplification circuit unit 2 specifically comprises an amplifier U1, and the model of the amplifier U1 is AD8008. The 3-pin of the amplifier U1 is electrically connected with the output end of the high-frequency signal acquisition unit 1, that is, the 3-pin of the amplifier U1 is electrically connected with the other end of the impedance matching resistor R5. The 4-pin of the amplifier U1 is electrically connected with the ground terminal AGND. The 2-pin of the amplifier U1 is electrically connected between the proportional resistor R3 and the proportional resistor R4, the other end of the proportional resistor R3 is electrically connected with the ground terminal AGND; the other end of the proportional resistor R4 is electrically connected with the 6-pin of the amplifier U1 on one hand and the ground terminal AGND through the filter capacitor C1 on the other hand; the 6-pin of the amplifier U1 is electrically connected with the high-speed switching diode VD1 through the impedance matching resistor R6 and the impedance matching resistor R7; the 7-pin of the amplifier U1 is electrically connected with the ground terminal AGND through the capacitor C3, electrically connected with the ground terminal AGND through the capacitor C2, electrically connected with the grounding terminal AGND through the electrolytic capacitor E1, and electrically connected with the power supply terminal VCC-A5V through the resistor R1. The amplifier U1 is powered by single-ended power supply, and the amplification ratio is formed by the proportional resistor R3 and the proportional resistor R4. The 2-pin of the amplifier U1 is the negative input terminal of the amplifier, and the 3-pin is the positive input terminal of the amplifier. The impedance of the amplifier U1 is adjusted through the impedance matching resistor R6 and the impedance matching resistor R7. The voltage signal converted by the high-frequency signal acquisition unit 1 is amplified by the amplification circuit unit 2, so as to improve the signal strength. The circuit is simple and reasonable, and the signal is stable and not distorted.

[0046] Embodiment 4

[0047] On the basis of embodiment 3, the technical features involved in the embodiment and the functions and roles of the technical features in the utility model are described in detail, so as to help the technical personnel in the field fully understand the technical scheme of the utility model and reproduce it.

[0048] As shown in Figure 2 the input end of the MCU main control chip 3 is also electrically connected with the temperature and pressure environment parameter monitoring module unit 7. The temperature and pressure environment parameter monitoring module unit 7 can monitor the temperature and pressure of the local environment at the same time; when the temperature changes, the pressure of the environment will also change, and the accuracy of monitoring is improved by monitoring the two parameters of temperature and pressure at the same time.

[0049] As shown in Figure 6As shown, the temperature and pressure environment parameter monitoring module unit 7 comprises a CN2 interface; the 1 pin and the 2 pin of the CN2 interface are used for plugging in the temperature and humidity sensor and form a loop with the MCU master control chip 3; the 3 pin and the 4 pin of the CN2 interface are used for plugging in the pressure sensor and form a loop with the MCU master control chip 3. The temperature and humidity sensor of the embodiment is of the AHT20 type, and the pressure sensor is of the BMP280 type. When the MCU master control chip 3 detects that the information sensed by the temperature and pressure environment parameter monitoring module unit 7 is abnormal, the MCU master control chip 3 will drive the alarm. The alarm here can share one alarm with the high-frequency signal acquisition unit 1, that is, both alarms are sent through the alarm module unit 5, or a separate alarm module unit can be additionally set.

[0050] The input voltage of the power module unit 4 of the embodiment is 12V direct current, and the output is 3.3V direct current voltage as the power supply end 3V3, the output is 5V direct current voltage for digital circuits as the power supply end VCC-5V, and the output is 5V voltage for analog circuits as the power supply end VCC-A5V. The power module unit 4 is a prior art circuit design, and details are not described here to avoid tedious writing.

[0051] As shown in the figure, Figure 7As shown, the alarm module unit 5 of the embodiment includes a two-way output relay RELAY1, and the specific model of the two-way output relay RELAY1 of the embodiment is G6S2-DC5V. The 1 pin of the two-way output relay RELAY1 is electrically connected with the power supply end VCC-5V, the 4 pin and the 5 pin of the two-way output relay RELAY1 are combined into an alarm output port, and are used for electrical connection with the upper decision unit 8; the 8 pin of the two-way output relay RELAY1 is electrically connected with the ground end GND through the resistor R35 and the light-emitting diode D3; the 9 pin of the two-way output relay RELAY1 is connected with the power supply end 3V3; the 12 pin of the two-way output relay RELAY1 is electrically connected with the power supply end VCC-5V through the diode VD3 on one hand, and is electrically connected with the collector of the triode Q1 on the other hand; the base of the triode Q1 is electrically connected with the MCU main control chip 3 through the resistor R21, and the node between the resistor R21 and the triode Q1 is also electrically connected with the ground end GND through the resistor R22, and the emitter of the triode Q1 is electrically connected with the ground end GND. One end of the resistor R21 is connected with the control pin of the MCU main control chip 3, i.e., the 39 pin of the MCU main control chip 3; the other end of the resistor R21 is connected with the base of the triode Q1, and the resistor R21 is a current limiting circuit, which aims to protect the triode Q1 and reduce power consumption. The resistor R22 is responsible for pulling down the base of the triode Q1 to 0V, so as to ensure that the power-on will not be misoperated. The diode VD3 is used to provide an energy discharge channel when the two-way output relay RELAY1 is released, so as to avoid the energy in the coil of the two-way output relay RELAY1 from rebounding to other units in the power supply system. The resistor R35 and the light-emitting diode D3 constitute an indicator. When the alarm occurs, i.e., the two-way output relay RELAY1 is actuated, the indicator will be turned on. The 4 pin and the 5 pin of the two-way output relay RELAY1 constitute the alarm output port, and are used to supply the upper decision unit 8, such as access to the comprehensive protection device to perform tripping operation, notify the operation and maintenance personnel, etc.

[0052] As Figure 8As shown, the communication module unit 6 comprises a communication signal conversion chip U8, and the model of the communication signal conversion chip U8 in the embodiment is SP3485. The 1st pin and the 4th pin of the communication signal conversion chip U8 are serial signal input and output ports, and are electrically connected with the MCU master chip 3. The 2nd pin and the 3rd pin of the communication signal conversion chip U8 are direction control pins, and are electrically connected with the MCU master chip 3. The 5th pin of the communication signal conversion chip U8 is electrically connected with the ground terminal GND. The 6th pin and the 7th pin of the communication signal conversion chip U8 are differential input and output ports, the 6th pin and the 7th pin of the communication signal conversion chip U8 are electrically connected with the resistance R31, the 6th pin of the communication signal conversion chip U8 is electrically connected with the power terminal 3V3 through the resistance R32 on one hand, and is electrically connected with the background data processing center 9 on the other hand. The 7th pin of the communication signal conversion chip U8 is electrically connected with the ground terminal GND through the resistance R30 on one hand, and is electrically connected with the background data processing center 9 on the other hand. The function of the communication signal conversion chip U8 is to convert serial data into differential signals. The 1st pin and the 4th pin of the communication signal conversion chip U8 are serial signal input and output ports, the 2nd pin and the 3rd pin thereof are direction control pins, and the 6th pin and the 7th pin thereof are differential input and output ports. The resistance R31 is a port matching resistance, and the resistance can reduce signal crosstalk.

[0053] In conclusion, the above is only a preferred embodiment of the utility model, and is not used to limit the range of the utility model implementation. Any equivalent changes and modifications of shape, structure, features and spirit within the scope of the utility model claims should be included in the scope of the utility model claims.

Claims

1. An intelligent ultra-high frequency cable partial discharge monitoring device, comprising an MCU master chip (3), a minimum working unit of the MCU master chip, and a power module unit (4) for providing working power supply, characterized in that: The input end of the MCU main control chip (3) is electrically connected with a high-frequency signal acquisition unit (1) for electrical connection with the ultrahigh-frequency sensor, the high-frequency signal acquisition unit (1) converts the high-frequency electromagnetic wave signal into a voltage signal, and inputs the converted signal to the amplification circuit unit (2) for amplification processing; the output end of the amplification circuit unit (2) is electrically connected with a first-order filter through a high-speed switching diode VD1; the first-order filter includes a resistor R14 and a capacitor C8 connected in parallel, and is used for filtering out electrical signals with a frequency value less than f1; the electrical signal processed by the first-order filter is electrically connected with the input end of a low-pass filter through an impedance matching resistor R8, the output end of the low-pass filter outputs a band-pass electrical signal to the MCU main control chip (3) through an impedance matching resistor R9 and a diode VD2; the cutoff frequency of the low-pass filter is f2, and the low-pass filter includes a capacitor C5 and a resistor R11 connected in parallel; the output end of the MCU main control chip (3) is electrically connected with an alarm module unit (5), and the output end of the alarm module unit (5) transmits alarm information to an upper decision unit (8). The MCU main control chip (3) is also bidirectionally connected with a background data processing center (9) through a communication module unit (6).

2. The intelligent ultra-high frequency cable partial discharge monitoring device according to claim 1, characterized in that: The value of f1 is 100 MHz, and the value of f2 is 1500 MHz.

3. The intelligent ultra-high frequency cable partial discharge monitoring device according to claim 1, characterized in that: The diode VD2 and the MCU main control chip (3) are also electrically connected with a third-order filter; the third-order filter includes a resistor R12 and a capacitor C7 connected in parallel; the cathode end of the diode VD2 is electrically connected with one end of the resistor R12, one end of the capacitor C7 and the MCU main control chip (3) through an impedance matching resistor R10; the other end of the resistor R12 and the other end of the capacitor C7 are both electrically connected with a ground end AGND.

4. The intelligent ultra-high frequency cable partial discharge monitoring device of claim 1, wherein: The input end of the MCU main control chip (3) is also electrically connected with a temperature and pressure environmental parameter monitoring module unit (7).

5. The intelligent ultra-high frequency cable partial discharge monitoring device according to claim 4, characterized in that: The temperature and pressure environmental parameter monitoring module unit (7) includes a CN2 connector; the 1 pin and the 2 pin of the CN2 connector are used for plugging a temperature and humidity sensor and form a loop with the MCU main control chip (3); the 3 pin and the 4 pin of the CN2 connector are used for plugging a pressure sensor and form a loop with the MCU main control chip (3).

6. The intelligent ultra-high frequency cable partial discharge monitoring device of claim 1, wherein: The high-frequency signal acquisition unit (1) comprises a radio frequency pickup chip U2 and an external interface PEX for plugging an ultrahigh frequency sensor, the 2-pin and 3-pin of the external interface PEX are electrically connected with a ground terminal AGND, the 1-pin of the external interface PEX is electrically connected with the ground terminal AGND through a radio frequency coupling capacitor C6, a noise reduction resistor R16, a radio frequency coupling capacitor C9 and a symmetric resistor R15, the two ends of the resistor R16 are electrically connected with the 2-pin and 3-pin of the radio frequency pickup chip U2 respectively, the 1-pin of the radio frequency pickup chip U2 is electrically connected with one end of a filter capacitor C4, a positive terminal of an electrolytic capacitor E2 and one end of a resistor R2, the other end of the resistor R2 is electrically connected with a power terminal VCC-A5V, the other end of the filter capacitor C4 and the negative terminal of the electrolytic capacitor E2 are electrically connected with the ground terminal AGND, the 4-pin of the radio frequency pickup chip U2 is electrically connected with one end of a filter capacitor C10, a positive terminal of an electrolytic capacitor E3 and one end of a resistor R17, the other end of the resistor R17 is electrically connected with the power terminal VCC-A5V, the negative terminal of the electrolytic capacitor E3 and the other end of the filter capacitor C10 are electrically connected with the ground terminal AGND, the 5-pin and 6-pin of the radio frequency pickup chip U2 are electrically connected with the ground terminal AGND, the 7-pin of the radio frequency pickup chip U2 is electrically connected with an input terminal of the amplification circuit unit (2) through a feedback resistor R13 and an impedance matching resistor R5, the 8-pin of the radio frequency pickup chip U2 is electrically connected between the feedback resistor R13 and the impedance matching resistor R5.

7. The intelligent ultra-high frequency cable partial discharge monitoring device of claim 1, wherein: The amplification circuit unit (2) comprises an amplifier U1, the 3-pin of the amplifier U1 is electrically connected with an output terminal of the high-frequency signal acquisition unit (1), the 4-pin of the amplifier U1 is electrically connected with the ground terminal AGND, the 2-pin of the amplifier U1 is electrically connected between a proportional resistor R3 and a proportional resistor R4, the other end of the proportional resistor R3 is electrically connected with the ground terminal AGND, the other end of the proportional resistor R4 is electrically connected with the ground terminal AGND through a filter capacitor C1 on one hand and is electrically connected with the 6-pin of the amplifier U1 on the other hand, the 6-pin of the amplifier U1 is electrically connected with the high-speed switching diode VD1 through an impedance matching resistor R6 and an impedance matching resistor R7, the 7-pin of the amplifier U1 is electrically connected with the ground terminal AGND through a capacitor C3, is electrically connected with the ground terminal AGND through a capacitor C2, is electrically connected with the ground terminal AGND through an electrolytic capacitor E1 and is electrically connected with a power terminal VCC-A5V through a resistor R1.

8. The intelligent ultra-high frequency cable partial discharge monitoring device of claim 1, wherein: The model of the MCU master control chip (3) is GD32F303RCT6, the input voltage of the power module unit (4) is 12V direct current, 3.3V direct current voltage is output as a power terminal 3V3, 5V direct current voltage is output as a power terminal VCC-5V for digital circuit and 5V voltage is output as a power terminal VCC-A5V for analog circuit.

9. The intelligent ultra-high frequency cable partial discharge monitoring device of claim 1, wherein: The alarm module unit (5) comprises a two-way output relay RELAY1, a 1 pin of the two-way output relay RELAY1 is electrically connected with a power supply end VCC-5V, a 4 pin and a 5 pin of the two-way output relay RELAY1 are combined into an alarm output port, and the alarm output port is electrically connected with the upper decision unit (8); an 8 pin of the two-way output relay RELAY1 is electrically connected with a grounding end GND through a resistor R35 and a light emitting diode D3; a 9 pin of the two-way output relay RELAY1 is connected with a power supply end 3V3; a 12 pin of the two-way output relay RELAY1 is electrically connected with the power supply end VCC-5V through a diode VD3 on one hand and is electrically connected with a collector of a triode Q1 on the other hand; a base of the triode Q1 is electrically connected with the MCU main control chip (3) through a resistor R21, a node between the resistor R21 and the triode Q1 is further electrically connected with the grounding end GND through a resistor R22, and an emitter of the triode Q1 is electrically connected with the grounding end GND.

10. The intelligent ultra-high frequency cable partial discharge monitoring device of claim 1, wherein: The communication module unit (6) comprises a communication signal conversion chip U8; a 1 pin and a 4 pin of the communication signal conversion chip U8 are serial signal input and output ports and are electrically connected with the MCU main control chip (3); a 2 pin and a 3 pin of the communication signal conversion chip U8 are direction control pins and are electrically connected with the MCU main control chip (3); a 5 pin of the communication signal conversion chip U8 is electrically connected with the grounding end GND; a 6 pin and a 7 pin of the communication signal conversion chip U8 are differential input and output ports, the 6 pin and the 7 pin of the communication signal conversion chip U8 are electrically connected with a resistor R31, the 6 pin of the communication signal conversion chip U8 is electrically connected with the power supply end 3V3 through a resistor R32 on one hand and is electrically connected with the background data processing center (9) on the other hand; the 7 pin of the communication signal conversion chip U8 is electrically connected with the grounding end GND through a resistor R30 on one hand and is electrically connected with the background data processing center (9) on the other hand.

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