CN111679162A - Insulation monitoring method and device for transformer substation cable - Google Patents
Insulation monitoring method and device for transformer substation cable Download PDFInfo
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- CN111679162A CN111679162A CN202010488581.3A CN202010488581A CN111679162A CN 111679162 A CN111679162 A CN 111679162A CN 202010488581 A CN202010488581 A CN 202010488581A CN 111679162 A CN111679162 A CN 111679162A
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
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Abstract
The invention provides an insulation monitoring method and device for a transformer substation cable, which comprises the following steps: acquiring three-phase voltage, three-phase current, grounding wire current and joint temperature of a cable of the transformer substation; optimizing the three-phase voltage, the three-phase current and the grounding wire current to obtain the processed three-phase voltage, the three-phase current and the grounding wire current; analyzing the change trend of the processed three-phase voltage and three-line current, comparing the joint temperature and the processed grounding wire current with corresponding preset thresholds respectively, and judging the aging condition of the insulating layer of the cable according to the analysis result and the comparison result. Carry out insulation monitoring to the cable in two aspects of electric property value and non-electric property value, can reflect the insulating ageing condition of cable comprehensively from the multi-angle, gather multiple characteristic vector simultaneously and can reduce because of the error that the uncontrollable factor influence led to the fact the monitoring result, improve insulation monitoring's accuracy and reliability.
Description
Technical Field
The invention belongs to the field of insulation monitoring, and particularly relates to an insulation monitoring method and device for a transformer substation cable.
Background
With the maturity of the manufacturing technology of cables and the reduction of the price, in order to improve the power supply reliability and reduce the municipal land for tower erection and simultaneously avoid single-phase earth faults caused by various reasons, the traditional overhead lines are increasingly replaced by the cables. With the increase of service life, under the influence of electric field, temperature, humidity, chemical corrosion and mechanical stress, the insulating layer of the cable is easy to age in various forms, so that the insulating layer is broken down to cause single-phase earth fault, and the reliability of urban power supply is influenced
In order to effectively monitor the insulation state of the cable, the characteristic quantity monitored by the prior art is single, is easily influenced by the noise of the operating environment, is difficult to comprehensively and effectively reflect the aging degree, and causes the unsatisfactory effect of insulation aging monitoring.
Disclosure of Invention
In order to solve the defects in the prior art, the invention provides an insulation monitoring method of a transformer substation cable, which comprises the following steps:
acquiring three-phase voltage, three-phase current, grounding wire current and joint temperature of a cable of the transformer substation;
optimizing the three-phase voltage, the three-phase current and the grounding wire current to obtain the processed three-phase voltage, the three-phase current and the grounding wire current;
analyzing the change trend of the processed three-phase voltage and three-line current, comparing the joint temperature and the processed grounding wire current with corresponding preset thresholds respectively, and judging the aging condition of the insulating layer of the cable according to the analysis result and the comparison result.
Optionally, the three-phase voltage, the three-phase current and the ground wire current are optimized to obtain the processed three-phase voltage, the processed three-phase current and the processed ground wire current, including:
respectively comparing the three-phase voltage u (T) and the three-phase current i at T acquired in the total sampling time T by a root mean square formula1(t) smoothing to obtain continuous three-phase voltage U and three-phase current I1；
The root mean square formula is:
wherein T is total sampling time in seconds, and the value range of T is a positive integer; n is the number of discrete values acquired in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and the value range of N is a positive integer; t is the sampling time; the U, I1、t、u(t)、i1The value range of (t) is positive number.
Optionally, the optimizing the three-phase voltage, the three-phase current and the current of the ground wire to obtain the processed three-phase voltage, the processed three-phase current and the current of the ground wire further includes:
respectively sampling T-time wiring current i acquired in total sampling time T by a root mean square formula2(t) smoothing to obtain continuous grounding wire current I2；
The root mean square formula is:
wherein T isSampling total time, wherein the unit is second, and the value range of T is a positive integer; n is the number of discrete values acquired in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and the value range of N is a positive integer; t is the sampling time; said I2、t、i2The value range of (t) is positive number.
Optionally, analyzing the trend of the processed three-phase voltage and three-line current, comparing the joint temperature and the processed ground wire current with corresponding preset thresholds respectively, and determining the aging condition of the insulating layer of the cable according to the analysis result and the comparison result, including:
respectively acquiring the change rates of the processed three-phase voltage and the three-phase current, matching the obtained change rates with reference change rates in a pre-established fault database, and when the match degrees of the change rates of the three-phase voltage and the three-phase current are both greater than a set fault threshold value, judging that the cable has faults due to the aging of an insulating layer, and outputting fault alarm information;
if no fault warning information is output, judging that the cable is aged when the current of the grounding wire is greater than a preset current threshold value of the grounding wire, and outputting aging warning information; and when the joint temperature is greater than a preset cable joint temperature threshold value, judging that the cable is aged, and outputting aging early warning information.
Optionally, the insulation monitoring method obtains a three-phase voltage, a three-phase current, a ground wire current and a joint temperature of a cable of the transformer substation through a sensor module, wherein the sensor module comprises a voltage acquisition module, a current acquisition module and a temperature acquisition module;
the voltage acquisition module comprises a voltage sensor for acquiring three-phase voltage and an amplifier for amplifying the acquired three-phase voltage;
the current acquisition module comprises a current sensor for acquiring three-phase current and grounding wire current and an amplifier for amplifying the acquired three-phase current and grounding wire current;
the temperature acquisition module comprises a thermistor for acquiring the joint temperature and an amplifier for amplifying the acquired joint temperature.
The invention also provides an insulation monitoring device of the transformer substation cable based on the same idea, and the insulation monitoring device comprises:
a sampling device: the method comprises the steps of obtaining three-phase voltage, three-phase current, grounding wire current and joint temperature of a cable of the transformer substation;
a data processing device: the device is used for optimizing the three-phase voltage, the three-phase current and the grounding wire current to obtain the processed three-phase voltage, the three-phase current and the grounding wire current;
a monitoring device: the device is used for analyzing the change trend of the processed three-phase voltage and three-wire current, comparing the joint temperature and the processed grounding wire current with corresponding preset thresholds respectively, and judging the aging condition of the insulating layer of the cable according to the analysis result and the comparison result.
Optionally, the data processing apparatus is specifically configured to:
respectively comparing the three-phase voltage u (T) and the three-phase current i at T acquired in the total sampling time T by a root mean square formula1(t) smoothing to obtain continuous three-phase voltage U and three-phase current I1；
The root mean square formula is:
wherein T is total sampling time in seconds, and the value range of T is a positive integer; n is the number of discrete values acquired in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and the value range of N is a positive integer; t is the sampling time; the U, I1、t、u(t)、i1The value range of (t) is positive number.
Optionally, the data processing apparatus is further configured to:
respectively sampling T-time electric wires collected in total sampling time T by a root mean square formulaCurrent i2(t) smoothing to obtain continuous grounding wire current I2；
The root mean square formula is:
wherein T is total sampling time in seconds, and the value range of T is a positive integer; n is the number of discrete values acquired in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and the value range of N is a positive integer; t is the sampling time; said I2、t、i2The value range of (t) is positive number.
Optionally, the monitoring device is specifically configured to:
respectively acquiring the change rates of the processed three-phase voltage and the three-phase current, matching the obtained change rates with reference change rates in a pre-established fault database, and when the match degrees of the change rates of the three-phase voltage and the three-phase current are greater than a set fault threshold value, judging that the cable has faults due to the aging of an insulating layer, and outputting fault alarm information;
if no fault warning information is output, judging that the cable is aged when the current of the grounding wire is greater than a preset current threshold value of the grounding wire, and outputting aging warning information; and when the joint temperature is greater than a preset cable joint temperature threshold value, judging that the cable is aged, and outputting aging early warning information.
Optionally, the sampling device acquires three-phase voltage, three-phase current, ground wire current and joint temperature of a cable of the transformer substation through a sensor module, and the sensor module comprises a voltage acquisition module, a current acquisition module and a temperature acquisition module;
the voltage acquisition module comprises a voltage sensor for acquiring three-phase voltage of a transformer substation cable and an amplifier for amplifying the acquired three-phase voltage;
the current acquisition module comprises a current sensor for acquiring the three-phase current of the cable of the transformer substation and the current of the grounding wire and an amplifier for amplifying the acquired three-phase current and the current of the grounding wire;
the temperature acquisition module comprises a thermistor and an amplifier, wherein the thermistor is used for acquiring the joint temperature of the substation cable, and the amplifier is used for amplifying the acquired joint temperature.
The technical scheme provided by the invention has the beneficial effects that:
gather conductor voltage electric current, earth connection electric current and the joint temperature of cable respectively and carry out insulation monitoring to the cable from two aspects of electric property value and non-electric property value as the characteristic vector, can follow the insulating ageing condition of multi-angle comprehensive reflection cable, gather multiple characteristic vector simultaneously and can reduce because of the error that uncontrollable factor influence led to the fact the monitoring result, improve insulation monitoring's accuracy and reliability.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
Fig. 1 is a schematic flow chart of a method for monitoring insulation of a substation cable according to the present invention;
FIG. 2 is a circuit diagram of collecting three phase voltages of a cable conductor;
FIG. 3 is a circuit diagram of collecting three phase current and ground line current of a cable conductor;
FIG. 4 is a circuit diagram of collecting the joint temperature of a cable;
fig. 5 is a block diagram of an insulation monitoring device for a substation cable according to the present invention.
Detailed Description
To make the structure and advantages of the present invention clearer, the structure of the present invention will be further described with reference to the accompanying drawings.
Example one
As shown in fig. 1, the present invention provides an insulation monitoring method for a substation cable, including:
s1: acquiring three-phase voltage, three-phase current, grounding wire current and joint temperature of a cable of the transformer substation;
s2: optimizing the three-phase voltage, the three-phase current and the grounding wire current to obtain the processed three-phase voltage, the three-phase current and the grounding wire current;
s3: analyzing the change trend of the processed three-phase voltage and three-line current, comparing the joint temperature and the processed grounding wire current with corresponding preset thresholds respectively, and judging the aging condition of the insulating layer of the cable according to the analysis result and the comparison result.
Gather the data that can reflect the insulating ageing condition from the conductor of cable, earth connection and the three angle of joint respectively, carry out insulating monitoring to the cable from two aspects of electric property value and non-electric property value, can reflect the insulating ageing condition of cable comprehensively from the multi-angle, gather multiple characteristic quantity simultaneously and can reduce because of the error that the uncontrollable factor influence led to the fact the monitoring result, improve the accuracy and the reliability of insulating monitoring.
The three-phase voltage, the three-phase current, the grounding wire current and the joint temperature of the transformer substation cable are obtained, and the method comprises the following steps: acquiring three-phase voltage and three-phase current of a cable conductor and grounding wire current of a cable based on a preset sampling rate; and acquiring the joint temperature of the cable through a temperature sensor.
A PCI bus-based data acquisition card PCI6221 from the American NI corporation is adopted, and the acquisition card integrates A-D conversion and digital I/O functions. To ensure accurate measurement and reconstruction of the signal, twice the highest frequency is used as the sampling rate according to the maximum frequency of the current of the ground line and the nyquist sampling theorem, and the sampling rate is 1.2MHz in the present embodiment.
In this embodiment, the model number is selected to
The voltage sensor is a capacitive sensor, can effectively prevent overvoltage and overcurrent impact due to the fact that a piezoresistor and a fusing resistor are arranged inside the voltage sensor, is good in linearity and high in measurement accuracy, and meets the requirement of insulation monitoring. For collecting electricityThe three-phase voltage circuit of the cable conductor is shown in fig. 2, diodes VD1 and VD3 which are sequentially connected in series are connected in series with VD2 and VD4 which are sequentially connected in series, a capacitor C1 is connected in parallel with diodes VD2 and VD4, a resistor R1 is connected in series with R2 and then connected in parallel with a capacitor C1, a transient diode TVS is connected in parallel with two ends of a resistor R2, a capacitor C2 is connected in series with a resistor R3 and then connected in parallel with a transient diode TVS, a connection node of the capacitor C2 and the transient diode TVS is grounded, a connection node of the resistor R3 and the capacitor C2 is connected with an inverting input end of the operational amplifier a through a resistor R4, a capacitor C3 is connected with an non-inverting input end of the operational amplifier a, a first end of the resistor R4 is connected with a first end of the capacitor C4, a second end of the capacitor C4 is grounded through the resistor R4, the resistor R4 is connected between the inverting input end and an output end of the operational amplifier a second end of the operational, the second terminal of the diode VD6 is grounded. And inputting 57.7V alternating voltage, conditioning the input voltage through the circuit structure, and obtaining the collected three-phase voltage of the cable conductor at the output end of the operational amplifier A.
In the embodiment, a current sensor with the model of SCT254FK is selected, and the current can be converted from 0-5A to 0-2.5mA so as to collect the three-phase current of the cable conductor in the following. As shown in fig. 3, the circuit for collecting three-phase current of a cable conductor and a current of a ground wire is characterized in that diodes VD1 and VD3 which are sequentially connected in series are connected in series with VD2 and VD4 which are sequentially connected in series, a capacitor C1 is connected in parallel with diodes VD2 and VD4, a resistor R2 is connected in parallel with a capacitor C1 and then connected in parallel with a transient diode TVS, a capacitor C2 is connected in series with a resistor R3 and then connected in parallel with the transient diode TVS, a connection node of the capacitor C2 and the transient diode TVS is grounded, a connection node of the resistor R3 and the capacitor C2 is connected with an inverting input terminal of the operational amplifier a through a resistor R4, a capacitor C3 is connected with an non-inverting input terminal of the operational amplifier a, a first end of the resistor R4 is connected with a first end of the capacitor C3, a second end of the capacitor C3 is grounded through a resistor R6, a resistor R5 is connected between the inverting input terminal and the output terminal of the operational amplifier a diode VD 86, the second end of the diode VD6 is grounded, and the collected three-phase current of the cable conductor is obtained at the output end of the operational amplifier A.
In the embodiment, a temperature sensor with the model number of JcJ100G is selected, a thermal resistance type Pt1000 is selected as an input signal, the temperature measuring range is-50-340 ℃, and the output is direct current of 0-5V. The circuit for collecting the joint temperature of the cable is shown in fig. 4, a first end of a thermistor group R2 is connected with a first end of a diode VD5, a second end of the thermistor group R2 passes through a transient diode TVS and a resistor R3 in sequence, the resistor R4 is connected with the inverting input end of the operational amplifier A, the first end of the capacitor C2 is connected between the resistor R3 and the resistor R4, the other end of the capacitor C2 is connected with the second end of the transient diode and grounded, the capacitor C3 is connected with the non-inverting input end of the operational amplifier A, the first end of the resistor R4 is connected with the first end of the capacitor C3, the second end of the capacitor C3 is grounded through a resistor R6, the resistor R5 is connected between the inverting input end and the output end of the operational amplifier A, the diodes VD5 and VD6 are connected in series, the output end of the operational amplifier A passes through the middle nodes of the diodes VD5 and VD6, the second end of the diode VD6 is grounded, and the output end of the operational amplifier A obtains a.
The optimization processing of the three-phase voltage, the three-phase current and the grounding wire current to obtain the processed three-phase voltage, the three-phase current and the grounding wire current comprises the steps of smoothing discrete voltage and discrete current acquired in the total sampling time T respectively through a root-mean-square formula to obtain continuous three-phase voltage and three-phase current;
the root mean square formula is:
wherein T is total sampling time in seconds and is a positive integer; n is the number of discrete numerical values collected in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and N is a positive integer;
u is a continuous three-phase voltage, I1Is a continuous three-phase current, t is a sampling time, u (t) is a three-phase voltage at t, i1(t) a three-phase current at t, said U, I1、t、u(t)、i1(t) are all positive numbers.
The method comprises the steps of optimizing three-phase voltage, three-phase current and grounding wire current to obtain the processed three-phase voltage, three-phase current and grounding wire current, and smoothing the collected current of the power connection wire in the total sampling time T through a root-mean-square formula to obtain continuous current of the power connection wire;
the root mean square formula is:
wherein T is total sampling time in seconds and is a positive integer; n is the number of discrete numerical values collected in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and N is a positive integer;
I2for continuous earth line current, t is the sampling instant, i2(t) a ground line current when t is said2、t、i2(t) are all positive numbers.
Since the voltage sensor and the current sensor are sampled based on a preset sampling rate, the acquired data are discrete. In practical application, the cable insulation aging is a slow gradual change process, so that data with continuity needs to be monitored, the aging condition of the insulation layer can be effectively reflected from the angle of the data change trend, and the sensitivity of insulation monitoring is improved.
In this embodiment, the three-phase voltage, the three-phase current and the grounding wire current of the conductor are optimized through an industrial personal computer, the industrial personal computer of the type IIPC4001D is selected as a hardware platform, and LabVIEW software is loaded to process and display data. This industrial computer is from taking the keyboard, convenient operation makes things convenient for the site work, possesses 5.7 cun TFT display screens simultaneously, but real-time display data. The industrial personal computer receives the collected three-phase voltage, three-phase current, grounding wire current and current corresponding to the joint temperature through power carrier waves carried by the power system.
The power line is used as a transmission medium by the power line carrier, other channels do not need to be built by additional investment, and with the continuous progress of the technology, the power line which can simultaneously transmit data, voice, video and power and integrates four wires is developed in middle and high voltage distribution lines in China. The data obtained from the insulation monitoring may also be transmitted using a power carrier. When power carrier transmission is carried out, data are collected by the voltage sensor, the current sensor and the temperature sensor, then proper coding and modulation technologies are selected to process collected signals into high-frequency signals and transmit the high-frequency signals on a power line, finally the high-frequency signals are demodulated through the demodulator, and the demodulated data are transmitted to the industrial personal computer.
The analysis three-phase voltage after handling, three-wire current's trend of change will connect the temperature and the earth connection electric current after handling respectively with the corresponding threshold value of predetermineeing, judge the ageing condition of insulating layer of cable according to analysis result and comparative result, include: respectively acquiring the change rates of the three-phase voltage and the three-phase current of the processed conductor; matching the obtained change rate with historical data in a fault database, judging that the cable has faults due to the aging of the insulating layer when the matching degree is simultaneously greater than a set fault threshold value, and outputting fault alarm information; if no fault warning information is output, comparing the current of the grounding wire with a preset current threshold of the grounding wire, if the current of the grounding wire is larger than the current threshold of the grounding wire, judging that the cable is aged, and outputting aging warning information, and meanwhile, comparing the joint temperature with a preset temperature threshold of a cable joint, and if the current of the grounding wire is larger than the temperature threshold of the cable joint, judging that the cable is aged, and outputting aging warning information.
The method for judging the aging condition of the insulating layer of the cable is realized based on LabVIEW software in an industrial personal computer, the fault early warning information and the aging early warning information can be displayed through a display screen of the industrial personal computer, phase voltage and phase current of an A phase, a B phase and a C phase of a cable conductor, and a grounding wire current value and a joint temperature value corresponding to the three-phase positions are displayed on a monitoring interface, and operation and maintenance personnel can check and know the aging condition of the insulating layer of the cable in time.
The insulation monitoring method for the substation cable is described below with reference to specific examples, and specifically includes:
the method comprises the following steps: based on 1A sampling rate of 2MHz, acquiring three-phase voltage of the cable conductor through a voltage sensor, acquiring three-phase current of the cable conductor and grounding wire current of the cable through a current sensor, and acquiring a current value I corresponding to the joint temperature of the cable through a temperature sensor3。
Step two: smoothing discrete voltage and discrete current acquired in each second by a root-mean-square formula to obtain continuous three-phase voltage and continuous three-phase current;
the root mean square formula is:
wherein T is total sampling time in seconds, and T is 1; n is the number of discrete numerical values collected in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and N is a positive integer;
u is a continuous three-phase voltage, I1Is a continuous three-phase current, t is a sampling time, u (t) is a three-phase voltage at t, i1(t) a three-phase current at t, said U, I1、t、u(t)、i1(t) are all positive numbers.
Smoothing the current of the power connection wire acquired in the total sampling time T by a root mean square formula to obtain continuous current of the power connection wire;
the root mean square formula is:
wherein T is total sampling time in seconds, and T is 1; n is the number of discrete numerical values collected in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and N is a positive integer;
I2for continuous earth line current, t is the sampling instant, i2(t) a ground line current when t is said2、t、i2(t) are all positive numbers.
Step three: i obtained in the step one is transmitted through power carrier waves3And U, I obtained in step two1、I2And transmitting to an industrial personal computer.
Step four: through the LabVIEW software pair U, I in the industrial personal computer1、I2And I3Analyzing to obtain U, I1Matching the obtained change rate with historical data in a fault database relative to the change rate of the last second, judging that the cable has faults due to the aging of the insulating layer when the matching degree is more than 90%, and outputting fault alarm information; if no fault alarm information is output, comparing I2And comparing the current threshold value with a preset ground wire current threshold value, if the current threshold value is larger than the ground wire current threshold value, judging that the cable is aged, outputting aging early warning information, and simultaneously comparing I3And if the corresponding joint temperature is greater than the preset cable joint temperature threshold, judging that the cable is aged, and outputting aging early warning information.
Example two
As shown in fig. 5, the present invention provides an insulation monitoring device 4 for a substation cable, where the insulation monitoring device 4 includes:
the sampling device 41: the method comprises the steps of obtaining three-phase voltage, three-phase current, grounding wire current and joint temperature of a cable of the transformer substation;
the data processing device 42: the device is used for optimizing the three-phase voltage, the three-phase current and the grounding wire current to obtain the processed three-phase voltage, the three-phase current and the grounding wire current;
the monitoring device 43: the device is used for analyzing the change trend of the processed three-phase voltage and three-wire current, comparing the joint temperature and the processed grounding wire current with corresponding preset thresholds respectively, and judging the aging condition of the insulating layer of the cable according to the analysis result and the comparison result.
Gather the data that can reflect the insulating ageing condition from the conductor of cable, earth connection and the three angle of joint respectively, carry out insulating monitoring to the cable from two aspects of electric property value and non-electric property value, can reflect the insulating ageing condition of cable comprehensively from the multi-angle, gather multiple characteristic quantity simultaneously and can reduce because of the error that the uncontrollable factor influence led to the fact the monitoring result, improve the accuracy and the reliability of insulating monitoring.
The sampling device 41 is specifically configured to: acquiring three-phase voltage and three-phase current of a cable conductor and grounding wire current of a cable based on a preset sampling rate; and acquiring the joint temperature of the cable through a temperature sensor.
A PCI bus-based data acquisition card PCI6221 from the American NI corporation is adopted, and the acquisition card integrates A-D conversion and digital I/O functions. To ensure accurate measurement and reconstruction of the signal, twice the highest frequency is used as the sampling rate according to the maximum frequency of the current of the ground line and the nyquist sampling theorem, and the sampling rate is 1.2MHz in the present embodiment.
In this embodiment, the model number is selected to
The voltage sensor is a capacitive sensor, can effectively prevent overvoltage and overcurrent impact due to the fact that a piezoresistor and a fusing resistor are arranged inside the voltage sensor, is good in linearity and high in measurement accuracy, and meets the requirement of insulation monitoring. As shown in fig. 2, a circuit for acquiring a three-phase voltage of a cable conductor includes diodes VD1 and VD3 connected in series in sequence, diodes VD2 and VD4 connected in series in sequence, a capacitor C1 connected in parallel with diodes VD2 and VD4, resistors R1 and R2 connected in series and then connected in parallel with a capacitor C1, a transient diode TVS connected in parallel at two ends of a resistor R2, a capacitor C2 connected in series with a resistor R3 and then connected in parallel with the transient diode TVS, a connection node of the capacitor C2 and the transient diode TVS is grounded, a connection node between the resistor R3 and the capacitor C2 is connected to an inverting input terminal of an operational amplifier a through a resistor R4, a capacitor C3 connected to an non-inverting input terminal of the operational amplifier a, a first terminal of the resistor R4 is connected to a first terminal of the capacitor C4, a second terminal of the capacitor C4 is grounded through a resistor R4, the resistor R4 is connected between the inverting input terminal and the output terminal of the operational amplifier a diode VD4, and an intermediate node VD4 connected in, the second terminal of the diode VD6 is grounded. Input AC voltage 57.7V, through the above-mentioned electricityThe circuit structure conditions the input voltage and obtains the collected three-phase voltage of the cable conductor at the output end of the operational amplifier A.
In the embodiment, a current sensor with the model of SCT254FK is selected, and the current can be converted from 0-5A to 0-2.5mA so as to collect the three-phase current of the cable conductor in the following. As shown in fig. 3, the circuit for collecting three-phase current of a cable conductor and a current of a ground wire is characterized in that diodes VD1 and VD3 which are sequentially connected in series are connected in series with VD2 and VD4 which are sequentially connected in series, a capacitor C1 is connected in parallel with diodes VD2 and VD4, a resistor R2 is connected in parallel with a capacitor C1 and then connected in parallel with a transient diode TVS, a capacitor C2 is connected in series with a resistor R3 and then connected in parallel with the transient diode TVS, a connection node of the capacitor C2 and the transient diode TVS is grounded, a connection node of the resistor R3 and the capacitor C2 is connected with an inverting input terminal of the operational amplifier a through a resistor R4, a capacitor C3 is connected with an non-inverting input terminal of the operational amplifier a, a first end of the resistor R4 is connected with a first end of the capacitor C3, a second end of the capacitor C3 is grounded through a resistor R6, a resistor R5 is connected between the inverting input terminal and the output terminal of the operational amplifier a diode VD 86, the second end of the diode VD6 is grounded, and the collected three-phase current of the cable conductor is obtained at the output end of the operational amplifier A.
In the embodiment, a temperature sensor with the model number of JcJ100G is selected, a thermal resistance type Pt1000 is selected as an input signal, the temperature measuring range is-50-340 ℃, and the output is direct current of 0-5V. The circuit for collecting the joint temperature of the cable is shown in fig. 4, a first end of a thermistor group R2 is connected with a first end of a diode VD5, a second end of the thermistor group R2 passes through a transient diode TVS and a resistor R3 in sequence, the resistor R4 is connected with the inverting input end of the operational amplifier A, the first end of the capacitor C2 is connected between the resistor R3 and the resistor R4, the other end of the capacitor C2 is connected with the second end of the transient diode and grounded, the capacitor C3 is connected with the non-inverting input end of the operational amplifier A, the first end of the resistor R4 is connected with the first end of the capacitor C3, the second end of the capacitor C3 is grounded through a resistor R6, the resistor R5 is connected between the inverting input end and the output end of the operational amplifier A, the diodes VD5 and VD6 are connected in series, the output end of the operational amplifier A passes through the middle nodes of the diodes VD5 and VD6, the second end of the diode VD6 is grounded, and the output end of the operational amplifier A obtains a.
The data processing device 42 is specifically configured to perform smoothing processing on the discrete voltage and the discrete current acquired within the total sampling time T through a root-mean-square formula, respectively, so as to obtain a continuous three-phase voltage and a continuous three-phase current;
the root mean square formula is:
wherein T is total sampling time in seconds and is a positive integer; n is the number of discrete numerical values collected in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and N is a positive integer;
u is a continuous three-phase voltage, I1Is a continuous three-phase current, t is a sampling time, u (t) is a three-phase voltage at t, i1(t) a three-phase current at t, said U, I1、t、u(t)、i1(t) are all positive numbers.
The data processing device 42 is further configured to perform smoothing processing on the power connection line current collected within the total sampling time T through a root mean square formula, respectively, to obtain continuous power connection line current;
the root mean square formula is:
wherein T is total sampling time in seconds and is a positive integer; n is the number of discrete numerical values collected in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and N is a positive integer;
I2for continuous earth line current, t is the sampling instant, i2(t) a ground line current when t is said2、t、i2(t) are all positive numbers.
Since the voltage sensor and the current sensor are sampled based on a preset sampling rate, the acquired data are discrete. In practical application, the cable insulation aging is a slow gradual change process, so that data with continuity needs to be monitored, the aging condition of the insulation layer can be effectively reflected from the angle of the data change trend, and the sensitivity of insulation monitoring is improved.
In this embodiment, the three-phase voltage, the three-phase current and the grounding wire current of the conductor are optimized through an industrial personal computer, the industrial personal computer of the type IIPC4001D is selected as a hardware platform, and LabVIEW software is loaded to process and display data. This industrial computer is from taking the keyboard, convenient operation makes things convenient for the site work, possesses 5.7 cun TFT display screens simultaneously, but real-time display data. The industrial personal computer receives the collected three-phase voltage, three-phase current, grounding wire current and current corresponding to the joint temperature through power carrier waves carried by the power system.
The power line is used as a transmission medium by the power line carrier, other channels do not need to be built by additional investment, and with the continuous progress of the technology, the power line which can simultaneously transmit data, voice, video and power and integrates four wires is developed in middle and high voltage distribution lines in China. The data obtained from the insulation monitoring may also be transmitted using a power carrier. When power carrier transmission is carried out, data are collected by the voltage sensor, the current sensor and the temperature sensor, then proper coding and modulation technologies are selected to process collected signals into high-frequency signals and transmit the high-frequency signals on a power line, finally the high-frequency signals are demodulated through the demodulator, and the demodulated data are transmitted to the industrial personal computer.
The monitoring device 43 is specifically configured to: respectively acquiring the change rates of the three-phase voltage and the three-phase current of the processed conductor; matching the obtained change rate with historical data in a fault database, judging that the cable has faults due to the aging of the insulating layer when the matching degree is simultaneously greater than a set fault threshold value, and outputting fault alarm information; if no fault warning information is output, comparing the current of the grounding wire with a preset current threshold of the grounding wire, if the current of the grounding wire is larger than the current threshold of the grounding wire, judging that the cable is aged, and outputting aging warning information, and meanwhile, comparing the joint temperature with a preset temperature threshold of a cable joint, and if the current of the grounding wire is larger than the temperature threshold of the cable joint, judging that the cable is aged, and outputting aging warning information.
The method for judging the aging condition of the insulating layer of the cable is realized based on LabVIEW software in an industrial personal computer, the fault early warning information and the aging early warning information can be displayed through a display screen of the industrial personal computer, phase voltage and phase current of an A phase, a B phase and a C phase of a cable conductor, and a grounding wire current value and a joint temperature value corresponding to the three-phase positions are displayed on a monitoring interface, and operation and maintenance personnel can check and know the aging condition of the insulating layer of the cable in time.
The sequence numbers in the above embodiments are merely for description, and do not represent the sequence of the assembly or the use of the components.
The above description is only exemplary of the present invention and should not be taken as limiting the invention, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. An insulation monitoring method for a substation cable is characterized by comprising the following steps:
acquiring three-phase voltage, three-phase current, grounding wire current and joint temperature of a cable of the transformer substation;
optimizing the three-phase voltage, the three-phase current and the grounding wire current to obtain the processed three-phase voltage, the three-phase current and the grounding wire current;
analyzing the change trend of the processed three-phase voltage and three-line current, comparing the joint temperature and the processed grounding wire current with corresponding preset thresholds respectively, and judging the aging condition of the insulating layer of the cable according to the analysis result and the comparison result.
2. The insulation monitoring method of the substation cable according to claim 1, wherein the optimizing the three-phase voltage, the three-phase current and the ground wire current to obtain the processed three-phase voltage, the three-phase current and the ground wire current comprises:
respectively comparing the three-phase voltage u (T) and the three-phase current i at T acquired in the total sampling time T by a root mean square formula1(t) smoothing to obtain continuous three-phase voltage U and three-phase current I1；
The root mean square formula is:
wherein T is total sampling time in seconds, and the value range of T is a positive integer; n is the number of discrete values acquired in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and the value range of N is a positive integer; t is the sampling time; the U, I1、t、u(t)、i1The value range of (t) is positive number.
3. The insulation monitoring method of the substation cable according to claim 1, wherein the optimization processing is performed on the three-phase voltage, the three-phase current and the ground wire current to obtain the processed three-phase voltage, the three-phase current and the ground wire current, and further comprising:
respectively sampling T-time wiring current i acquired in total sampling time T by a root mean square formula2(t) smoothing to obtain continuous grounding wire current I2；
The root mean square formula is:
wherein T is total sampling time in seconds, and the value range of T is a positive integer; n is the number of discrete values collected in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and the N is takenThe value ranges are positive integers; t is the sampling time; said I2、t、i2The value range of (t) is positive number.
4. The insulation monitoring method of the substation cable according to claim 1, wherein the analyzing the processed three-phase voltage and three-wire current variation trend, comparing the joint temperature and the processed ground wire current with corresponding preset thresholds respectively, and determining the insulation layer aging condition of the cable according to the analysis result and the comparison result comprises:
respectively acquiring the change rates of the processed three-phase voltage and the three-phase current, matching the obtained change rates with reference change rates in a pre-established fault database, and when the match degrees of the change rates of the three-phase voltage and the three-phase current are both greater than a set fault threshold value, judging that the cable has faults due to the aging of an insulating layer, and outputting fault alarm information;
if no fault warning information is output, judging that the cable is aged when the current of the grounding wire is greater than a preset current threshold value of the grounding wire, and outputting aging warning information; and when the joint temperature is greater than a preset cable joint temperature threshold value, judging that the cable is aged, and outputting aging early warning information.
5. The insulation monitoring method of the substation cable according to claim 1, wherein the insulation monitoring method obtains three-phase voltage, three-phase current, ground wire current and joint temperature of the substation cable through a sensor module, and the sensor module comprises a voltage acquisition module, a current acquisition module and a temperature acquisition module;
the voltage acquisition module comprises a voltage sensor for acquiring three-phase voltage and an amplifier for amplifying the acquired three-phase voltage;
the current acquisition module comprises a current sensor for acquiring three-phase current and grounding wire current and an amplifier for amplifying the acquired three-phase current and grounding wire current;
the temperature acquisition module comprises a thermistor for acquiring the joint temperature and an amplifier for amplifying the acquired joint temperature.
6. An insulation monitoring device for a substation cable, the insulation monitoring device comprising:
a sampling device: the method comprises the steps of obtaining three-phase voltage, three-phase current, grounding wire current and joint temperature of a cable of the transformer substation;
a data processing device: the device is used for optimizing the three-phase voltage, the three-phase current and the grounding wire current to obtain the processed three-phase voltage, the three-phase current and the grounding wire current;
a monitoring device: the device is used for analyzing the change trend of the processed three-phase voltage and three-wire current, comparing the joint temperature and the processed grounding wire current with corresponding preset thresholds respectively, and judging the aging condition of the insulating layer of the cable according to the analysis result and the comparison result.
7. The insulation monitoring device of the substation cable according to claim 6, wherein the data processing device is specifically configured to:
respectively comparing the three-phase voltage u (T) and the three-phase current i at T acquired in the total sampling time T by a root mean square formula1(t) smoothing to obtain continuous three-phase voltage U and three-phase current I1；
The root mean square formula is:
wherein T is total sampling time in seconds, and the value range of T is a positive integer; n is the number of discrete values acquired in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and the value range of N is a positive integer; t is the sampling time; the U, I1、t、u(t)、i1The value range of (t) is positive number.
8. The insulation monitoring device of a substation cable according to claim 6, characterized in that said data processing device is further configured to:
respectively sampling T-time wiring current i acquired in total sampling time T by a root mean square formula2(t) smoothing to obtain continuous grounding wire current I2；
The root mean square formula is:
wherein T is total sampling time in seconds, and the value range of T is a positive integer; n is the number of discrete values acquired in the total sampling time and is calculated by the product of the total sampling time T and the sampling rate, and the value range of N is a positive integer; t is the sampling time; said I2、t、i2The value range of (t) is positive number.
9. The insulation monitoring device of a substation cable according to claim 6, characterized in that the monitoring device is specifically configured to:
respectively acquiring the change rates of the processed three-phase voltage and the three-phase current, matching the obtained change rates with reference change rates in a pre-established fault database, and when the match degrees of the change rates of the three-phase voltage and the three-phase current are greater than a set fault threshold value, judging that the cable has faults due to the aging of an insulating layer, and outputting fault alarm information;
if no fault warning information is output, judging that the cable is aged when the current of the grounding wire is greater than a preset current threshold value of the grounding wire, and outputting aging warning information; and when the joint temperature is greater than a preset cable joint temperature threshold value, judging that the cable is aged, and outputting aging early warning information.
10. The insulation monitoring device of the substation cable according to claim 6, wherein the sampling device acquires three-phase voltage, three-phase current, ground wire current and joint temperature of the substation cable through a sensor module, and the sensor module comprises a voltage acquisition module, a current acquisition module and a temperature acquisition module;
the voltage acquisition module comprises a voltage sensor for acquiring three-phase voltage of a transformer substation cable and an amplifier for amplifying the acquired three-phase voltage;
the current acquisition module comprises a current sensor for acquiring the three-phase current of the cable of the transformer substation and the current of the grounding wire and an amplifier for amplifying the acquired three-phase current and the current of the grounding wire;
the temperature acquisition module comprises a thermistor and an amplifier, wherein the thermistor is used for acquiring the joint temperature of the substation cable, and the amplifier is used for amplifying the acquired joint temperature.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112485720A (en) * | 2020-12-21 | 2021-03-12 | 南方电网电力科技股份有限公司 | Cable insulation defect detection method and device |
| CN117368675A (en) * | 2023-12-05 | 2024-01-09 | 广东环威电线电缆股份有限公司 | Cable insulation performance testing method and related device |
| CN118364407A (en) * | 2024-04-30 | 2024-07-19 | 山东文登抽水蓄能有限公司 | Intelligent switching station fault diagnosis system and method for pumped storage power station |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1834673A (en) * | 2006-03-06 | 2006-09-20 | 西安交通大学 | Insulating state on-line monitoring method of cross-linked PE cable |
| CN101464488A (en) * | 2009-01-16 | 2009-06-24 | 上海慧东电气设备有限公司 | On-line monitoring system for high voltage cable |
| CN102879716A (en) * | 2012-09-24 | 2013-01-16 | 哈尔滨理工大学 | Online monitoring method and device for main insulation of three-phase cable under metal sheath cross interconnection |
| CN103326352A (en) * | 2013-05-21 | 2013-09-25 | 国家电网公司 | Method for identifying power distribution network cable line local overheating risks |
| CN105676092A (en) * | 2016-03-29 | 2016-06-15 | 中国石油大学(北京) | Method and system for monitoring insulation level of substation power cable |
| CN205506253U (en) * | 2016-02-29 | 2016-08-24 | 西安理工大学 | Cable head monitoring protection device that generates heat based on PTC |
| CN205720418U (en) * | 2016-06-21 | 2016-11-23 | 上海谷元电气科技有限公司 | High tension cable circulating current detector |
| CN108037423A (en) * | 2017-12-08 | 2018-05-15 | 哈尔滨理工大学 | A kind of high-voltage cable insulating on-Line Monitor Device and method based on double differential CT methods |
| CN108490329A (en) * | 2018-03-12 | 2018-09-04 | 国网江苏省电力有限公司徐州供电分公司 | Power distribution network crosslinking polyethylene-insulated cable insulation state monitoring apparatus and monitoring method |
| CN109631987A (en) * | 2018-12-03 | 2019-04-16 | 国网浙江省电力有限公司电力科学研究院 | A kind of multi-parameter integrated monitoring and warning system of cable |
| CN110687408A (en) * | 2019-10-15 | 2020-01-14 | 清华大学 | Cable insulation monitoring method and device |
| CN111157801A (en) * | 2019-12-31 | 2020-05-15 | 国网北京市电力公司 | Method and device for detecting dielectric loss of cable, storage medium and processor |
-
2020
- 2020-06-02 CN CN202010488581.3A patent/CN111679162B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1834673A (en) * | 2006-03-06 | 2006-09-20 | 西安交通大学 | Insulating state on-line monitoring method of cross-linked PE cable |
| CN101464488A (en) * | 2009-01-16 | 2009-06-24 | 上海慧东电气设备有限公司 | On-line monitoring system for high voltage cable |
| CN102879716A (en) * | 2012-09-24 | 2013-01-16 | 哈尔滨理工大学 | Online monitoring method and device for main insulation of three-phase cable under metal sheath cross interconnection |
| CN103326352A (en) * | 2013-05-21 | 2013-09-25 | 国家电网公司 | Method for identifying power distribution network cable line local overheating risks |
| CN205506253U (en) * | 2016-02-29 | 2016-08-24 | 西安理工大学 | Cable head monitoring protection device that generates heat based on PTC |
| CN105676092A (en) * | 2016-03-29 | 2016-06-15 | 中国石油大学(北京) | Method and system for monitoring insulation level of substation power cable |
| CN205720418U (en) * | 2016-06-21 | 2016-11-23 | 上海谷元电气科技有限公司 | High tension cable circulating current detector |
| CN108037423A (en) * | 2017-12-08 | 2018-05-15 | 哈尔滨理工大学 | A kind of high-voltage cable insulating on-Line Monitor Device and method based on double differential CT methods |
| CN108490329A (en) * | 2018-03-12 | 2018-09-04 | 国网江苏省电力有限公司徐州供电分公司 | Power distribution network crosslinking polyethylene-insulated cable insulation state monitoring apparatus and monitoring method |
| CN109631987A (en) * | 2018-12-03 | 2019-04-16 | 国网浙江省电力有限公司电力科学研究院 | A kind of multi-parameter integrated monitoring and warning system of cable |
| CN110687408A (en) * | 2019-10-15 | 2020-01-14 | 清华大学 | Cable insulation monitoring method and device |
| CN111157801A (en) * | 2019-12-31 | 2020-05-15 | 国网北京市电力公司 | Method and device for detecting dielectric loss of cable, storage medium and processor |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112485720A (en) * | 2020-12-21 | 2021-03-12 | 南方电网电力科技股份有限公司 | Cable insulation defect detection method and device |
| CN112485720B (en) * | 2020-12-21 | 2021-09-14 | 南方电网电力科技股份有限公司 | Cable insulation defect detection method and device |
| CN117368675A (en) * | 2023-12-05 | 2024-01-09 | 广东环威电线电缆股份有限公司 | Cable insulation performance testing method and related device |
| CN117368675B (en) * | 2023-12-05 | 2024-03-19 | 广东环威电线电缆股份有限公司 | Cable insulation performance testing method and related device |
| CN118364407A (en) * | 2024-04-30 | 2024-07-19 | 山东文登抽水蓄能有限公司 | Intelligent switching station fault diagnosis system and method for pumped storage power station |
| CN118364407B (en) * | 2024-04-30 | 2024-10-01 | 山东文登抽水蓄能有限公司 | Intelligent switching station fault diagnosis system and method for pumped storage power station |
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