CN117929936A - Impact explosion detection method and device and cable joint - Google Patents
Impact explosion detection method and device and cable joint Download PDFInfo
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- CN117929936A CN117929936A CN202311631892.0A CN202311631892A CN117929936A CN 117929936 A CN117929936 A CN 117929936A CN 202311631892 A CN202311631892 A CN 202311631892A CN 117929936 A CN117929936 A CN 117929936A
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Abstract
The method and the device for detecting the impact explosion and the cable joint are characterized in that the method comprises the following steps: simultaneously connecting an impact simulation power supply and a power frequency power supply to two sides of the cable joint to simulate lightning impact and operation impact of power equipment respectively, and assembling an explosion-proof shell outside the cable joint; feeding back the working state of the cable connector by using a voltage and current sensor, and adjusting the output parameters of the impact simulation power supply based on the working state; and judging the breakdown time and the breakdown critical condition of the cable joint based on the working state, and monitoring the explosion impact force of the explosion-proof shell through a piezoelectric sensor. The method reforms the outer side surface of the cable joint and ensures the monitoring capability of the piezoelectric sensor.
Description
Technical Field
The invention relates to the field of power systems, in particular to a method and a device for detecting impact explosion and a cable joint.
Background
The power cable is an important device for electric energy transmission in a power transmission line, is usually laid in a tunnel, calandria and bent frame mode, and causes electric field distortion and insulation performance degradation of a high-voltage cable joint due to factors such as rough installation, long-distance transportation, long-term load and the like, and finally generates power frequency arc discharge of a high-voltage cable core wire and an outer shielding layer/grounding, and even explosion or fire.
In order to prevent fire disaster and other secondary accidents caused by explosion due to short-circuit faults of the high-voltage cable, many research institutions and enterprises begin to research and design a middle joint of the high-voltage cable with an explosion-proof shell, and the impact resistance of the explosion-proof shell is usually tested by adopting a certain equivalent of explosive. With the development of computer simulation technology, the explosion-proof characteristic of the middle joint of the high-voltage cable with the explosion-proof shell under the action of the power frequency current arc can be obtained through simulation calculation, but the research literature on the aspect is not much disclosed. Importantly, no comprehensive consideration is given to the electromagnetic environment in which the high-voltage cable actually operates in the explosive explosion test or the computer simulation calculation, so that the feasibility verification of exact explosion impact force data and design schemes cannot be provided for the explosion-proof structure design of the middle joint of the high-voltage cable with the explosion-proof shell.
In view of the foregoing, there is a need for a method, apparatus, and cable connector for detecting an impact explosion.
Disclosure of Invention
In order to solve the defects in the prior art, the invention provides an impact explosion detection method, an impact explosion detection device and a cable joint, which are used for realizing the measurement of breakdown time and breakdown critical conditions of the cable joint and the explosion force of an explosion-proof shell.
The invention adopts the following technical scheme.
The first aspect of the invention relates to a method for detecting impact explosion, comprising the following steps: simultaneously connecting an impact simulation power supply and a power frequency power supply to two sides of a cable joint to simulate lightning impact and operation impact of power equipment respectively, and assembling an explosion-proof shell outside the cable joint; the working state of the cable connector is fed back by utilizing a voltage sensor and a current sensor, and the output parameters of the impact simulation power supply are adjusted based on the working state; and judging the breakdown time and the breakdown critical condition of the cable joint based on the working state, and monitoring the explosion impact force of the explosion-proof shell through the piezoelectric sensor.
Preferably, the impulse analog power supply is a pulse voltage source with controllable signal intensity and adjustable time parameter; the power frequency power supply is a power frequency current source with controllable signal intensity.
Preferably, the impact simulation power supply and the power frequency power supply are simultaneously connected to two sides of the cable joint, and the cable joint further comprises: two sides of the cable joint respectively form an injection end and a reflux end, and one sides of the injection end and the reflux end are positioned in the explosion-proof shell; the other sides of the injection end and the reflux end are respectively fixed with a metal connecting plate, and an impact simulation power supply, a power frequency power supply and a voltage sensor are connected in parallel at two sides of the cable joint through the metal connecting plates.
Preferably, the cable joint and the piezoelectric sensor are arranged on an explosion detection test platform; and the cable connector is provided with an impact explosive force detection end, and the impact explosive force detection end passes through the explosion-proof shell through the transmission rod to be in contact connection with the piezoelectric sensor.
Preferably, the voltage and current sensor is used for feeding back the working state of the cable joint, and adjusting the output parameter of the impact simulation power supply based on the working state, and the method further comprises the following steps: the energy storage capacitor C11 and the energy storage capacitor C2 are respectively charged through a first adjustable high-voltage charging unit DC1 and a second adjustable high-voltage charging unit DC 2; and measuring the voltages of the energy storage capacitor C11 and the energy storage capacitor C2, and controlling the on-off states of the discharge switch G11 and the discharge switch G2 through discharge pulses when the energy storage capacitor C11 and the energy storage capacitor C2 reach preset voltages so as to realize the output of impulse analog voltage and power frequency current.
Preferably, the voltage stage of the first adjustable high-voltage charging unit DC1 is preset; on an initial stage, output of impulse analog voltage and power frequency current is realized, and working states of the cable connectors fed back by the voltage and current sensors are collected; if the working state is that the cable connector is normally conducted, the voltage stage is increased, impulse analog voltage and power frequency current are continuously output on the increased voltage stage, and the working state is collected until the working state is that the cable connector breaks down; and recording a critical voltage value when the cable connector breaks down.
The second aspect of the invention relates to an impact explosion detection device utilizing the method in the first aspect of the invention, wherein the device comprises an impact simulation power supply, a power frequency power supply, a cable joint provided with an explosion-proof shell, a voltage and current sensor, a piezoelectric sensor and a computer control and data acquisition, analysis and processing unit; the impulse simulation power supply and the power frequency power supply are used for being connected to two sides of the cable joint to simulate a fault line with impulse voltage; the voltage and current sensor is used for feeding back the working state of the cable joint; the piezoelectric sensor is used for monitoring the explosion impact force of the explosion-proof shell; the computer control and data acquisition analysis processing unit is used for receiving feedback of the voltage and current sensors, adjusting output parameters of the impact simulation power supply based on the fed back working state, judging breakdown time and breakdown critical conditions of the cable joint based on the working state, and acquiring explosion impact force and explosion limit parameters.
The third aspect of the invention relates to a cable joint, which comprises conductor copper 4, a stress cone 1, a high-voltage shield 5 and an outer sheath 9, wherein an SIR7 and a pouring sealant 8 are sequentially arranged in the outer sheath 9, the stress cone 1 and the outer side of the high-voltage shield 5 of the cable joint from inside to outside; SIR7 is set in a trapezoid mode, the lower bottom surface of the trapezoid is covered on the stress cone 1 and the high-voltage shield 5, and pouring sealant 8 is set between SIR and an outer sheath 9 in a uniform thickness; the pouring sealant 8 and the outer jacket 9 extend over a predetermined distance to the side of the stress cone 1 remote from the high voltage shield 5.
Preferably, the outer sheath 9 extends to a predetermined distance from the side of the stress cone 1 remote from the high voltage shield 5, and further comprises: the cross section of the cable joint sequentially comprises conductor copper 4, a conductor shield 3, XLPE2, an insulating shield 13, a buffer layer 12, pouring sealant 8, a copper shell 10 and an outer sheath 9 from inside to outside.
The buffer layer 12 is arranged outside the cut-off position of the pouring sealant 8 from the side of the stress cone 1 away from the high-voltage shielding 5; besides the cut-off position of the pouring sealant 8, an alumina protector 11 is also arranged between the buffer layer 12 and the outer sheath 9.
Compared with the prior art, the impact explosion detection method and device and the cable joint have the advantages that the breakdown time and the breakdown critical condition of the cable joint and the explosion force of the explosion-proof shell are measured, the outer side face of the cable joint is modified, and the monitoring capability of the pressure-maintaining electric sensor is ensured.
The beneficial effects of the invention also include:
1. According to the design test scheme of the actual running environment of the high-voltage cable intermediate joint with the explosion-proof shell, the situation that the high-voltage cable intermediate joint with the explosion-proof shell bears power frequency overcurrent, overvoltage or direct-current overvoltage is fully considered, the scene that the high-voltage cable intermediate joint bears lightning overvoltage and lightning surge voltage of the natural environment of the atmosphere is considered, and the situation that switching equipment (such as a breaker and the like) in a power transmission line is frequently switched on and off to generate operation overvoltage is examined. The simulation scheme integrates the scenes, and ensures the consistency of the explosion initiation reasons and conditions of the explosion test and the actual high-voltage cable intermediate joint.
2. The impulse voltage time parameter of the impulse simulation power supply can cover the wave front time and duration of the lightning impulse voltage wave and the operation impulse voltage wave of the power equipment, and ensure that the test can obtain the combined voltage of the high-voltage cable intermediate connector with the explosion-proof shell under the conditions of lightning impulse, adjustable impulse voltage and power frequency current.
3. The internal relation between the impact force born by the insulating shell of the middle joint of the high-voltage cable with the explosion-proof shell and the amplitude of the injected power frequency current is obtained through accurate simulation, and the technical blank in the field is filled.
4. The method reduces the whole explosion process, firstly simulates the breakdown arc, and secondly provides sufficient power frequency current on the basis of the breakdown arc, thereby accurately simulating the whole fault process of the cable joint before explosion, ensuring traceability of the explosion cause, charging the impact force of the cable joint and the destructive power of the breakdown arc in each time period before explosion, and being applicable to the design, detection and improvement of various cable joints and explosion-proof shells, the experimental data has high test practicability and high result confidence.
5. In order to ensure the effectiveness and reliability of monitoring data of the piezoelectric sensor, the method designs a cable joint outer side surface structure which can be in pressure connection with the connecting rod and effectively conduct impact force, so that the effectiveness of the measuring structure is improved, the related parameters of breakdown critical conditions and explosion critical impact force of the cable joint are improved, and the safety attribute of the cable joint is effectively improved.
Drawings
FIG. 1 is a schematic diagram of an embodiment of a method for detecting an impact explosion of a cable joint according to the present invention;
FIG. 2 is a schematic view of a piezoelectric transducer connected to a cable joint in an impact explosion detection method for the cable joint according to the present invention;
FIG. 3 is a schematic flow chart of lightning breakdown in a method for detecting impulse explosion of a cable joint according to the present invention;
FIG. 4 is a schematic flow chart of a method for detecting impulse explosion of a cable joint according to the present invention, wherein the method is used for implementing lightning and equipment operation combined breakdown;
fig. 5 is a schematic longitudinal section of a cable connector according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. The described embodiments of the invention are only some, but not all, embodiments of the invention. All other embodiments of the invention not described herein, which are obtained from the embodiments described herein, should be within the scope of the invention by those of ordinary skill in the art without undue effort based on the spirit of the present invention.
Fig. 1 is a schematic diagram of an embodiment of an impact explosion detection method for a cable joint according to the present invention. The first aspect of the invention relates to an impact explosion detection method, which comprises the steps of 1 to 3.
And step 1, connecting an impact simulation power supply and a power frequency power supply to two sides of the cable joint simultaneously so as to simulate lightning impact and operation impact of power equipment respectively, and assembling an explosion-proof shell outside the cable joint.
In order to simulate the impact explosion scene of the cable joint, the invention provides a measuring method and a testing device based on the combined action of the impact voltage and the power frequency current with adjustable time parameters. The power frequency current power supply with controllable intensity comprises an impact analog power supply with controllable intensity and adjustable time parameters. The impulse simulation power supply is a pulse voltage source with controllable signal intensity and adjustable time parameter; the power frequency power supply is a power frequency current source with controllable signal intensity.
The impact simulation power supply comprises a first adjustable high-voltage charging unit DC1, an energy storage capacitor C11, a discharging switch G11 and a voltage stabilizing unit; the first adjustable high-voltage charging unit DC1 is connected in parallel with two sides of the energy storage capacitor C11 through a resistor RC 1; the energy storage capacitor C11 discharges to the voltage stabilizing unit through the discharging switch G1, and the voltage stabilizing unit is connected to two sides of the cable joint in parallel. The voltage stabilizing unit comprises adjustable resistors RF1 and RT1 and a waveform forming capacitor C12. The resistor RC1 is a charging current limiting resistor. The adjustable high-voltage charging unit DC1 is used for respectively or jointly simulating a lightning impulse voltage waveform of 1.2V/50 mu s and an electric equipment operation impulse voltage waveform of 250V/2500 mu s.
In the working process, the first adjustable high-voltage charging unit DC1 is an adjustable high-voltage direct-current charging power supply, and charges the energy storage capacitor element C11 in the voltage generation loop after outputting voltage, and outputs a shock voltage wave with adjustable amplitude and adjustable time parameter so as to meet the test requirements of different levels of high-voltage cable joints.
The time parameter and duration of the impulse voltage waveform are adjustable, the optimal rising time and duration of the impulse voltage waveform can be obtained through a combined test with a power frequency current power supply, and the criterion of the optimal time parameter is to ensure the stable work of the power frequency current arc matched with the impulse voltage waveform. The output current of the power frequency current power supply can be adjusted through the discharge voltage of the oscillation loop after the parameters of the voltage source are determined.
The power frequency power supply comprises a second adjustable high-voltage charging unit DC2, an energy storage capacitor C2, a discharging switch G2 and a steady-flow capacitor L; the second adjustable high-voltage charging unit DC2 is connected in parallel with the two sides of the energy storage capacitor C2 through a resistor RC 2; the energy storage capacitor C2 is connected in parallel to the two sides of the cable joint through the discharging switch G2 and the steady-flow capacitor L. The resistor RC2 is a charging current-limiting resistor, the energy storage capacitor C2 and the inductor L work in a resonance state, and the resonance frequency is 50-60Hz.
Preferably, the impact simulation power supply and the power frequency power supply are simultaneously connected to two sides of the cable joint, and the cable joint further comprises: two sides of the cable joint respectively form an injection end and a reflux end, and one sides of the injection end and the reflux end are positioned in the explosion-proof shell; the other sides of the injection end and the reflux end are respectively fixed with a metal connecting plate, and an impact simulation power supply, a power frequency power supply and a voltage sensor are connected in parallel at two sides of the cable joint through the metal connecting plates.
The core and the high-voltage shield/ground layer of the intermediate connector of the high-voltage cable with the explosion-proof housing to be tested are mounted on the insulating housing of the cable connector, and the structure of the connector, which is connected with the core and the outer shield of the cable, is led to the insulating housing in the manner of a cable or a copper conductor. The high voltage shield/ground layer may be a high voltage shield or an insulating shield of the cable.
Fig. 2 is a schematic view showing the construction of a piezoelectric sensor connected cable joint in the impact explosion detection method for cable joint according to the present invention. As shown in fig. 2, preferably, the cable connector and the piezoelectric sensor are mounted on an explosion detection test platform; and the cable connector is provided with an impact explosive force detection end, and the impact explosive force detection end passes through the explosion-proof shell through the transmission rod to be in contact connection with the piezoelectric sensor.
The piezoelectric sensor is closely contacted with the insulating shell through a cylindrical transmission rod, and the lower end face of the cylindrical transmission rod is closely contacted with the surface of the piezoelectric sensor. In order to ensure that the cable joint insulating housing is in close contact with the cylindrical transfer rod, the method improves the cable joint.
And 2, feeding back the working state of the cable connector by using a voltage and current sensor, and adjusting the output parameters of the impact simulation power supply based on the working state.
Preferably, the energy storage capacitor C11 and the energy storage capacitor C2 are respectively charged by the first adjustable high-voltage charging unit DC1 and the second adjustable high-voltage charging unit DC 2; and measuring the voltages of the energy storage capacitor C11 and the energy storage capacitor C2, and controlling the on-off states of the discharge switch G11 and the discharge switch G2 through discharge pulses when the energy storage capacitor C11 and the energy storage capacitor C2 reach preset voltages so as to realize the output of impulse analog voltage and power frequency current.
The voltage and current sensors and the recording devices such as oscilloscopes connected with the voltage and current sensors are also connected to the corresponding access systems. The voltage sensor is connected in parallel with the two ends of the core wire and the shielding layer/grounding layer of the middle joint of the high-voltage cable with the explosion-proof shell and is used for measuring the output voltage of the middle joint of the high-voltage cable. And a power frequency current sensor is sleeved on an electric connecting wire between the high-voltage cable intermediate connector and the reflux end of the power supply and used for recording the power frequency follow-up arc current injected after the insulation breakdown of the high-voltage cable intermediate connector with the explosion-proof shell.
The computer control and data acquisition analysis processing unit is used for monitoring and controlling the test process, detecting, recording and processing the output voltage and the output current and the explosion impact force detected by the explosion impact force detecting device.
The computer control and data management unit controls the combined impact discharge of the voltage source and the current source. In addition, the power frequency current parameters and the impact force formed by the power frequency arc, which act on the middle joint of the high-voltage cable with the explosion-proof housing, are respectively extracted by the current sensor, the voltage sensor and the piezoelectric sensor and then are sent to the computer measurement and control and data management unit, and the rule between the impact force of the arc born by the middle joint of the high-voltage cable with the explosion-proof housing and the power frequency current parameters flowing through the middle joint of the high-voltage cable with the explosion-proof housing is obtained through processing and analysis.
And 3, judging the breakdown time and the breakdown critical condition of the cable joint based on the working state, and monitoring the explosion impact force of the explosion-proof shell through the piezoelectric sensor.
Fig. 3 is a schematic flow chart of lightning breakdown in the impact explosion detection method for the cable joint according to the present invention. As shown in fig. 3, the voltage stage of the first adjustable high-voltage charging unit DC1 is preset; on the initial stage, output of impulse analog voltage and power frequency current is realized, and working states of cable connectors fed back by voltage and current sensors are collected; if the working state is that the cable connector is normally conducted, the voltage stage is increased, impulse analog voltage and power frequency current are continuously output on the increased voltage stage, and the working state is collected until the working state is that the cable connector breaks down; and recording a critical voltage value when the cable connector breaks down.
In order to obtain the breakdown arc, the method controls the impulse voltage parameters output by the impulse voltage power supply with controllable intensity and adjustable time parameters through a computer control and data acquisition, analysis and processing unit.
The method comprises the steps of setting a discharge voltage value of a surge voltage power supply with controllable strength and time parameters on a computer human-computer interactive display interface of a computer control and data processing analysis processing unit, wherein the discharge voltage value is at least greater than a critical surge voltage breakdown amplitude of an explosion-proof shell injection end of a middle joint of a tested high-voltage cable obtained through an experimental method. The high-voltage cable middle connector can be ensured to be broken down between the injection end and the reflux end, and the power frequency current arc can be reliably initiated.
In particular, if the breakdown voltage value of the cable joint is known, it can be directly input. If not known, the charge voltage, waveform forming resistance and load capacitance parameters of the storage capacitor C11 can be adjusted by a computer, for example.
And gradually increasing the discharge voltage of the impulse voltage power supply with adjustable time parameter until the time parameter and the amplitude parameter of the impulse voltage waveform can stably trigger the subsequent power frequency current value, wherein the peak value of the impulse voltage corresponding to the condition is defined as the critical impulse voltage breakdown of the middle joint of the tested high-voltage cable.
The amplitude of the output voltage of the adjustable high-voltage direct-current charging power supply can also realize the regulation and control of the computer on the output voltage of the high-voltage direct-current charging power supply in a communication mode, so that the discharge voltage of the power frequency current power supply is gradually increased according to the test requirements of lightning impulse voltage output with different amplitudes, a group of power frequency current output values corresponding to the discharge voltage can be obtained, and the method can record the rule and realize analysis.
The amplitude of the output voltage of the adjustable high-voltage direct-current charging power supply can also be regulated and controlled by a computer in a communication mode, so that the test requirements of different power frequency current outputs are met.
FIG. 4 is a schematic flow chart of a method for detecting impulse explosion of a cable joint according to the present invention, wherein the method is used for implementing lightning and equipment operation combined breakdown.
In simulating the voltage, the method may implement a single simulation of the lightning strike voltage, the equipment operating strike voltage, or a simulation of a combined lightning and equipment operating voltage. And selecting according to test requirements.
When the breakdown discharge of the injection end and the reflux end of the middle joint of the high-voltage cable under the action of the impact voltage with adjustable time parameters is ensured, the stable breakdown discharge between the injection end and the reflux end is ensured, and the output current of the power frequency current power supply with controllable intensity is controlled by the control unit.
The computer control and data processing and analyzing unit obtains signals from the voltage sensor, the current sensor and the piezoelectric sensor through a communication interface of the oscilloscope, processes and analyzes the received signals to obtain an array of impact force and power frequency current intensity born by the explosion-proof shell of the middle joint of the high-voltage cable, and the limit threshold value of the impact force born by the explosion-proof shell of the middle joint of the high-voltage cable can be obtained through the analysis processing of the computer control and data processing and analyzing unit.
The second aspect of the invention relates to an impact explosion detection device utilizing the method of the first aspect of the invention, the device comprises an impact simulation power supply, a power frequency power supply, a cable joint provided with an explosion-proof shell, a voltage and current sensor, a piezoelectric sensor and a computer control and data acquisition, analysis and processing unit; the impulse simulation power supply and the power frequency power supply are used for being connected to two sides of the cable joint to simulate a fault line with impulse voltage; the voltage and current sensor is used for feeding back the working state of the cable joint; the piezoelectric sensor is used for monitoring the explosion impact force of the explosion-proof shell; the computer control and data acquisition analysis processing unit is used for receiving feedback of the voltage and current sensors, adjusting output parameters of the impact simulation power supply based on the fed back working state, judging breakdown time and breakdown critical conditions of the cable joint based on the working state, and acquiring explosion impact force and explosion limit parameters.
Fig. 5 is a schematic longitudinal section of a cable connector according to the present invention. As shown in fig. 5, in a third aspect of the present invention, a cable connector is related to, including a conductor copper 4, a stress cone 1, a high voltage shield 5 and an outer sheath 9, wherein SIR7 and a pouring sealant 8 are sequentially arranged in the outer sheath 9 of the cable connector, and outside the stress cone 1 and the high voltage shield 5 from inside to outside; SIR7 is set in a trapezoid mode, the lower bottom surface of the trapezoid is covered on the stress cone 1 and the high-voltage shield 5, and pouring sealant 8 is set between SIR and an outer sheath 9 in a uniform thickness; the pouring sealant 8 and the outer jacket 9 extend over a predetermined distance to the side of the stress cone 1 remote from the high voltage shield 5.
It is easily conceivable that the transmission of impact forces is achieved when the circular transmission rod is connected to the outer jacket 9 of the outer side of the cable joint by means of an explosion proof housing. This requires the outer side of the cable joint to be planar to ensure connection. At the same time, the improvement should not weaken the detection capability of the piezoelectric sensor, and the cable joint is not damaged by external force caused by non-explosion due to the reaction of impact force.
For this reason, the improved SIR has a larger volume to ensure that the outer side is planar. The pouring sealant 8 is arranged in a uniform thickness, and the pouring sealant 8 and the outer sheath 9 extend to a preset distance from one side of the stress cone 1, which is far away from the high-voltage shielding 5, so that damage of an external structure of the cable joint caused by external force is prevented, and the transmission rod is ensured to be connected with the cable joint more firmly.
Preferably, the outer sheath 9 extends to a predetermined distance from the side of the stress cone 1 remote from the high voltage shield 5, and further comprises: the cross section of the cable joint sequentially comprises conductor copper 4, a conductor shield 3, XLPE2, an insulating shield 13, a buffer layer 12, pouring sealant 8, a copper shell 10 and an outer sheath 9 from inside to outside.
The buffer layer 12 is arranged outside the cut-off position of the pouring sealant 8 from the side of the stress cone 1 away from the high-voltage shielding 5; an alumina sheath 11 is arranged between the buffer layer 12 and the outer sheath 9 beyond the cut-off position of the pouring sealant 8.
In the invention, the buffer layer 12 has the functions of electric conduction, mechanical buffer and longitudinal water resistance, and mainly consists of semiconductive water resistance expansion bands, buffer cotton and other materials.
The alumina sheath 11 is used for protecting conductors and insulating layers inside the cable, and can isolate the cable from external contact and prevent the cable from being mechanically damaged, so that the service life of the cable is prolonged.
The copper shell 10 provides protection of the cable from the ground and insulating layers, prevents the cable from external or electromagnetic interference, and ensures the stability and reliability of the operation of the cable.
Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which is intended to be covered by the claims.
Claims (10)
1. A method of detecting an impact explosion, the method comprising the steps of:
simultaneously connecting an impact simulation power supply and a power frequency power supply to two sides of the cable joint to simulate lightning impact and operation impact of power equipment respectively, and assembling an explosion-proof shell outside the cable joint;
Feeding back the working state of the cable connector by using a voltage and current sensor, and adjusting the output parameters of the impact simulation power supply based on the working state;
And judging the breakdown time and the breakdown critical condition of the cable joint based on the working state, and monitoring the explosion impact force of the explosion-proof shell through a piezoelectric sensor.
2. A method of detecting an impact explosion for a cable joint according to claim 1, wherein:
the impact simulation power supply is a pulse voltage source with controllable signal intensity and adjustable time parameters;
the power frequency power supply is a power frequency current source with controllable signal intensity.
3. A method of detecting an impact explosion for a cable joint according to claim 1, wherein:
the impact simulation power supply and the power frequency power supply are simultaneously connected to two sides of the cable joint, and the cable joint further comprises:
two sides of the cable joint respectively form an injection end and a reflux end, and one sides of the injection end and the reflux end are positioned in the explosion-proof shell;
the other sides of the injection end and the reflux end are respectively fixed with a metal connecting plate, and the impact simulation power supply, the power frequency power supply and the voltage sensor are connected in parallel at two sides of the cable joint through the metal connecting plates.
4. A method of detecting an impact explosion for a cable joint according to claim 1, wherein:
The cable connector and the piezoelectric sensor are arranged on an explosion detection test platform; and
The cable connector is provided with an impact explosive force detection end, and the impact explosive force detection end passes through the explosion-proof shell through the transmission rod to be connected with the piezoelectric sensor in a contact mode.
5. A method of detecting an impact explosion for a cable joint according to claim 1, wherein:
the said utilization voltage, current sensor feedback the working condition of the said cable joint, and adjust the output parameter of the said impact simulation power based on the said working condition, further include:
The energy storage capacitor C11 and the energy storage capacitor C2 are respectively charged through a first adjustable high-voltage charging unit DC1 and a second adjustable high-voltage charging unit DC 2;
And measuring the voltages of the energy storage capacitor C11 and the energy storage capacitor C2, and controlling the on-off states of the discharge switch G11 and the discharge switch G2 through discharge pulses when the energy storage capacitor C11 and the energy storage capacitor C2 reach preset voltages so as to realize the output of impulse analog voltage and power frequency current.
6. A method for impact explosion detection for a cable joint according to claim 5, wherein:
Presetting a voltage stage of the first adjustable high-voltage charging unit DC 1;
on an initial stage, output of impulse analog voltage and power frequency current is realized, and working states of the cable connectors fed back by the voltage and current sensors are collected;
If the working state is that the cable connector is normally conducted, the voltage stage is increased, impulse analog voltage and power frequency current are continuously output on the increased voltage stage, and the working state is collected until the working state is that the cable connector breaks down;
And recording a critical voltage value when the cable connector breaks down.
7. An impact explosion detection device using the method of any one of claims 1 to 12, characterized in that:
The device comprises an impact simulation power supply, a power frequency power supply, a cable joint provided with an explosion-proof shell, a voltage and current sensor, a piezoelectric sensor and a computer control and data acquisition, analysis and processing unit;
The impact simulation power supply and the power frequency power supply are used for being connected to two sides of the cable joint to simulate a fault line with impact voltage;
The voltage and current sensor is used for feeding back the working state of the cable joint;
the piezoelectric sensor is used for monitoring the explosion impact force of the explosion-proof shell;
And the computer control and data acquisition analysis processing unit is used for receiving the feedback of the voltage and current sensors, adjusting the output parameters of the impact simulation power supply based on the fed back working state, judging the breakdown time and the breakdown critical condition of the cable joint based on the working state, and acquiring the explosion impact force and the explosion limit parameters.
8. The utility model provides a cable joint, includes conductor copper (4), stress cone (1), high voltage shield (5) and oversheath (9), its characterized in that:
SIR (7) and pouring sealant (8) are sequentially arranged in an outer sheath (9) of the cable joint, outside the stress cone (1) and the high-voltage shield (5) from inside to outside;
The SIR (7) is arranged in a trapezoid mode, the lower bottom surface of the trapezoid is covered on the stress cone (1) and the high-voltage shield (5),
The pouring sealant (8) is arranged between the SIR and the outer sheath (9) with uniform thickness;
The pouring sealant (8) and the outer sheath (9) extend to a preset distance on one side of the stress cone (1) away from the high-voltage shielding (5).
9. A cable joint according to claim 1, characterized in that:
The outer sheath (9) extends to a preset distance on one side of the stress cone (1) away from the high-voltage shielding (5), and further comprises:
The cross section of the cable joint sequentially comprises conductor copper (4), a conductor shield (3), XLPE (2), an insulating shield (13), a buffer layer (12), pouring sealant (8), a copper shell (10) and an outer sheath (9) from inside to outside.
10. A cable joint according to claim 9, wherein:
The buffer layer (12) is arranged outside the cut-off position of the pouring sealant (8) from the side of the stress cone (1) away from the high-voltage shielding (5);
Besides the cut-off position of the pouring sealant (8), an alumina sheath (11) is arranged between the buffer layer (12) and the outer sheath (9).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311631892.0A CN117929936A (en) | 2023-11-30 | 2023-11-30 | Impact explosion detection method and device and cable joint |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311631892.0A CN117929936A (en) | 2023-11-30 | 2023-11-30 | Impact explosion detection method and device and cable joint |
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| Publication Number | Publication Date |
|---|---|
| CN117929936A true CN117929936A (en) | 2024-04-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311631892.0A Pending CN117929936A (en) | 2023-11-30 | 2023-11-30 | Impact explosion detection method and device and cable joint |
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| Country | Link |
|---|---|
| CN (1) | CN117929936A (en) |
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2023
- 2023-11-30 CN CN202311631892.0A patent/CN117929936A/en active Pending
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