CN111025099B - Simulation model and method for partial discharge detection - Google Patents
Simulation model and method for partial discharge detection Download PDFInfo
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- CN111025099B CN111025099B CN201911236247.2A CN201911236247A CN111025099B CN 111025099 B CN111025099 B CN 111025099B CN 201911236247 A CN201911236247 A CN 201911236247A CN 111025099 B CN111025099 B CN 111025099B
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Abstract
The embodiment of the invention discloses a simulation model and a method for partial discharge detection, wherein the simulation model is established by Matlab/Simulink software, and comprises the following steps: the device comprises a power supply unit for supplying power, a test article unit for simulating partial discharge, a power supply side interference unit for simulating a power supply side interference signal, a ground grid side interference unit for simulating a ground grid side interference signal, a filtering unit for filtering and a detection unit for detecting a partial discharge signal; the power supply unit is respectively electrically connected with the power supply side interference unit, the ground grid side interference unit, the filtering unit and the detection unit, the test sample unit is respectively electrically connected with the filtering unit and the detection unit, and the detection unit is also electrically connected with the filtering unit. The embodiment of the invention realizes the accurate simulation of the partial discharge detection and has strong universality and applicability.
Description
Technical Field
The invention relates to the technical field of partial discharge, in particular to a simulation model and a simulation method for partial discharge detection.
Background
In order to ensure the safe and reliable operation of the electrical equipment, the voltage resistance and partial discharge tests are required to be carried out on the electrical equipment so as to check whether the insulation performance of the equipment meets the requirements. However, due to the complex test field environment, background partial discharge amount introduced by various interference signals exceeds standard, and interference from a power supply side and a ground network side is difficult to eliminate, so that the test cannot be performed. The identification and elimination of the interference become key points and difficulties of withstand voltage and partial discharge tests. At present, the research on the propagation path and the propagation process of the interference signals brought by a power supply side and a ground network side is less at home and abroad. And the parameters of related filtering elements are adjusted by adopting a field trial mode to inhibit the influence of interference signals on the detection result, so that the time, the economy and the labor cost are higher. The prior art adopts a simulation means to carry out the test of partial discharge detection, and has poor universality.
Disclosure of Invention
The embodiment of the invention provides a simulation model and a simulation method for partial discharge detection, which aim to solve the problem of poor universality of the simulation model for partial discharge detection in the prior art.
In a first aspect, a simulation model for partial discharge detection is provided, where the simulation model is built by Matlab/Simulink software, and the simulation model includes: the device comprises a power supply unit for supplying power, a test article unit for simulating partial discharge, a power supply side interference unit for simulating a power supply side interference signal, a ground grid side interference unit for simulating a ground grid side interference signal, a filtering unit for filtering and a detection unit for detecting a partial discharge signal; the power supply unit is electrically connected with the power supply side interference unit, the ground grid side interference unit, the filtering unit and the detection unit respectively, the test sample unit is electrically connected with the filtering unit and the detection unit respectively, and the detection unit is also electrically connected with the filtering unit;
wherein the detection unit includes: the circuit comprises a first terminal, a second terminal, a third terminal, a coupling capacitor, a first impedance component, a second impedance component, a first switch, a second switch, a third switch and a fourth switch, wherein when the first switch and the third switch are closed, the second switch and the fourth switch are opened; or, when the second switch and the fourth switch are closed, the first switch and the third switch are disconnected;
the first terminal is used for being electrically connected with the filtering unit, the second terminal is used for being electrically connected with the test sample unit, and the third terminal is used for being electrically connected with the earth screen side interference unit;
one polar plate of the coupling capacitor is electrically connected with the first terminal, the other polar plate of the coupling capacitor is electrically connected with one end of the first switch and one end of the second switch respectively, the other end of the first switch is electrically connected with one end of the first impedance component, and the other end of the second switch is electrically connected with the third terminal;
one ends of the third switch and the fourth switch are respectively electrically connected with the second terminal, the other end of the third switch is electrically connected with the third terminal, and the other end of the fourth switch is electrically connected with one end of the second impedance component;
the third terminal is also electrically connected to the other end of the first impedance component and the other end of the second impedance component, respectively.
In a second aspect, a simulation method for partial discharge detection is provided, including:
establishing the simulation model of the partial discharge detection through Matlab/Simulink software;
setting parameters of a simulation model of the partial discharge detection;
and simulating the detection of the partial discharge signal by adopting the simulation model for the partial discharge detection.
Therefore, the embodiment of the invention has strong universality and applicability, provides an experimental simulation platform for the research of the transmission of the interference signals at the power supply side/the ground grid side of the partial discharge detection loop, realizes the accurate simulation of the transmission characteristics of the partial discharge signals in the circuit caused by air gap defects, and after the interference signals at the power supply side and the ground grid side are added, the accurate simulation of the transmission characteristics of the partial discharge signals in the circuit can be realized, the series or parallel connection relation between the impedance of the detection unit and the test sample unit can be selected according to the actual situation, the type of the impedance can be selected, the parameters of each element can be set according to the actual requirement, the simulation waveform of a simulation model can be output in real time, and the specific characteristics and the suppression measures of the transmission of the interference signals at the power supply side/the ground grid side of the partial discharge detection loop can be further researched by utilizing the simulation result.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention 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 that other drawings can be obtained according to these drawings without inventive labor.
FIG. 1 is a schematic circuit diagram of a simulation model for partial discharge detection according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a circuit structure of a detection unit of a simulation model of partial discharge detection according to an embodiment of the present invention;
FIG. 3 is a schematic circuit diagram of a filter unit of a simulation model for partial discharge detection according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a circuit configuration of a power supply unit of a simulation model of partial discharge detection according to an embodiment of the present invention;
FIG. 5 is a flow chart of a simulation method of partial discharge detection of an embodiment of the present invention;
FIG. 6 is a first schematic diagram of a current path of a detecting unit of a simulation model of partial discharge detection according to an embodiment of the present invention;
FIG. 7 is a second schematic diagram of a current path of a detection unit of a simulation model of partial discharge detection according to an embodiment of the present invention;
FIG. 8 is a third schematic diagram of the current path of the detection unit of the simulation model of partial discharge detection according to the embodiment of the present invention;
FIG. 9 is a fourth schematic current path diagram of a detection unit of a simulation model of partial discharge detection according to an embodiment of the present invention;
FIG. 10 is a waveform diagram of the output voltage of the power supply unit after the Gaussian noise signal is added to the power supply side interference unit according to the embodiment of the invention;
fig. 11 is a schematic diagram of a power supply unit outputting a voltage waveform after fourier transform after a gaussian noise signal is added to a power supply side interference unit according to an embodiment of the present invention;
FIG. 12 is a diagram of the voltage and discharge pulse waveforms of the third capacitor simulated by the embodiment of the invention;
FIG. 13 is a schematic diagram of the waveform of the voltage across the impedance of the circuit connected to the detection unit when the simulation model for partial discharge detection according to the embodiment of the present invention does not have the filter unit;
FIG. 14 is a diagram illustrating a Fourier transformed waveform of a voltage across an impedance of a circuit connected to a detection unit when a simulation model of partial discharge detection according to an embodiment of the present invention does not include a filter unit;
fig. 15 shows a simulation model of partial discharge detection according to an embodiment of the present invention, where R is 500 Ω and L is 1 × 10-3H, in the filtering unit, the waveform schematic diagram of the voltage at two ends of the impedance of the connecting circuit of the detection unit;
fig. 16 shows a simulation model of partial discharge detection according to an embodiment of the present invention, where R is 500 Ω and L is 1 × 10-3When the filter unit is used, the waveform of the voltage at two ends of the impedance connected into the circuit of the detection unit is subjected to Fourier transform;
fig. 17 is a waveform diagram of a voltage across an impedance of a circuit connected to a detection unit when a simulation model of partial discharge detection according to an embodiment of the present invention has a filter unit with R of 2000 Ω and L of 0.1H;
fig. 18 is a schematic diagram of a fourier transform of a waveform of a voltage across an impedance of a circuit connected to a detection unit when a simulation model of partial discharge detection according to an embodiment of the present invention includes a filter unit having an R of 2000 Ω and an L of 0.1H.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention discloses a simulation model for partial discharge detection. The simulation model is established by Matlab/Simulink software. As shown in fig. 1, the simulation model includes: the device comprises a power supply unit 1 for supplying power, a test article unit 2 for simulating partial discharge, a power supply side interference unit 3 for simulating power supply side interference signals, a ground grid side interference unit 4 for simulating ground grid side interference signals, a filtering unit 5 for filtering and a detection unit 6 for detecting partial discharge signals.
Specifically, the power supply unit 1 is electrically connected to the power supply side interference unit 3, the ground grid side interference unit 4, the filtering unit 5, and the detection unit 6, respectively. The sample unit 2 is electrically connected to the filter unit 5 and the detection unit 6, respectively. The detection unit 6 is also electrically connected to the filtering unit 5.
As shown in fig. 2, the detection unit 6 includes: a first terminal F1, a second terminal O, a third terminal G, a coupling capacitance Ck, a first impedance component, a second impedance component, a first switch K1, a second switch K2, a third switch K3 and a fourth switch K4.
The first terminal F1 is used to electrically connect the filter unit 5. The second terminal O is used for electrically connecting the sample unit 2. The third terminal G is used to electrically connect to the grid-side interfering unit 4. One plate of the coupling capacitor Ck is electrically connected to the first terminal F1. The other plate of the coupling capacitor Ck is electrically connected to one end of the first switch K1 and the second switch K2, respectively. The other end of the first switch K1 is electrically connected to one end of a first impedance component. The other end of the second switch K2 is electrically connected to the third terminal G. One ends of the third switch K3 and the fourth switch K4 are electrically connected to the second terminal O, respectively. The other end of the third switch K3 is electrically connected to the third terminal G. The other end of the fourth switch K4 is electrically connected to one end of the second impedance component. The third terminal G is also electrically connected to the other end of the first impedance component and the other end of the second impedance component, respectively.
By establishing the detection unit of the simulation model, for the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4, the following two switching states can be realized:
(1) when the first switch K1 and the third switch K3 are closed, the second switch K2 and the fourth switch K4 are open.
In this case, the impedance and the coupling capacitor Ck can be connected in series, and then the impedance and the coupling capacitor Ck are connected in parallel with the test sample unit 2 as a whole, so that the detection process of the partial discharge signal when one end of the test sample unit 2 is grounded can be simulated.
(2) When the second switch K2 and the fourth switch K4 are closed, the first switch K1 and the third switch K3 are open.
In this case, the impedance and the sample unit 2 can be connected in series, and then the impedance and the sample unit 2 are connected in parallel with the coupling capacitor Ck, so that the detection process of the partial discharge signal when both ends of the sample unit 2 are not grounded can be simulated.
Specifically, in order to facilitate the implementation of the above-described switching states, a first not gate N1 and a second not gate N2 may be provided. An output terminal of the first not gate N1 is electrically connected to one terminal of the first switch K1. An output terminal of the second not gate N2 is electrically connected to one terminal of the third switch K3. The input terminal of the first not gate N1 and the input terminal of the second not gate N2 can input the SP _ sel signal through the Matlab/Simulink software main interface. Thus, in Matlab/Simulink software, only one switching signal SP _ sel needs to be given by the Constant element, and the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4 receive the signal through the From element, so that the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4 can be simultaneously controlled. For example, SP _ sel ═ 1 indicates that the control switch is closed, and SP _ sel ═ 0 indicates that the control switch is open. Then, when the control signal of SP _ sel ═ 1 is input to the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4 at the same time through the main interface of Matlab/Simulink software, the first not gate N1 and the second not gate N2 convert the control signal into SP _ sel ═ 0 to be output, then the second switch K2 and the fourth switch K4 are closed, the first switch K1 and the third switch K3 are opened, and the local discharge detection process when both ends of the test sample unit 2 are not grounded is simulated; when the control signal of SP _ sel ═ 0 is input at the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4 at the same time through the main interface of the software, the first not gate N1 and the second not gate N2 convert the control signal into SP _ sel ═ 1 output, then the first switch K1 and the third switch K3 are closed, the second switch K2 and the fourth switch K4 are opened, and the partial discharge detection process when one end of the test sample unit 2 is grounded is simulated.
Therefore, the simulation model for detecting the partial discharge can simulate the process of generating the partial discharge signal and the interference signal and simulating the process of detecting the partial discharge signal, and can simulate the detection process of the partial discharge signal when one end of the test sample unit 2 is grounded or both ends of the test sample unit are not grounded, so that the simulation model for detecting the partial discharge has good universality and strong applicability.
Preferably, the first impedance component comprises: a fifth switch K5, a sixth switch K6, a first impedance Z1 and a second impedance Z2. The second impedance component includes: a seventh switch K7, an eighth switch K8, a third impedance Z3 and a fourth impedance Z4. The first impedance Z1 and the third impedance Z3 are of the same type and may be, for example, RLC impedances. The second impedance Z2 and the fourth impedance Z4 are of the same type and may be, for example, RC impedances. It should be understood that the type of impedance of the present invention is not limited thereto, and other types of impedances can be selected according to actual requirements. The other end of the first switch K1 is electrically connected to one ends of a fifth switch K5 and a sixth switch K6, respectively. The other end of the fourth switch K4 is electrically connected to one ends of a seventh switch K7 and an eighth switch K8, respectively. One end of the first impedance Z1 is electrically connected to the other end of the fifth switch K5, and the other end of the first impedance Z1 is electrically connected to the third terminal G. One end of the second impedance Z2 is electrically connected to the other end of the sixth switch K6, and the other end of the second impedance Z2 is electrically connected to the third terminal G. One end of the third impedance Z3 is electrically connected to the other end of the seventh switch K7, and the other end of the third impedance Z3 is electrically connected to the third terminal G. One end of the fourth impedance Z4 is electrically connected to the other end of the eighth switch K8, and the other end of the fourth impedance Z3 is electrically connected to the third terminal G.
By establishing the first impedance component and the second impedance component of the above simulation model, for the fifth switch K5, the sixth switch K6, the seventh switch K7, and the eighth switch K8, the switching states of the following two cases can be realized:
(1) when the fifth switch K5 and the seventh switch K7 are closed, the sixth switch K6 and the eighth switch K8 are opened.
In this case, the detection unit 6 is connected to the first impedance Z1 and the third impedance Z3.
(2) When the sixth switch K6 and the eighth switch K8 are closed, the fifth switch K5 and the seventh switch K7 are opened.
In this case, the detection unit 6 is connected to the second impedance Z2 and the fourth impedance Z4.
Specifically, in order to facilitate the implementation of the above-described switching states, a third not gate N3 and a fourth not gate N4 may be provided. An output terminal of the third not gate N3 is electrically connected to the fifth switch K5, and an output terminal of the fourth not gate N4 is electrically connected to the seventh switch K7. The input terminal of the third not gate N3 and the input terminal of the fourth not gate N4 can input the Z _ sel signal through the Matlab/Simulink software main interface. Thus, in Matlab/Simulink software, only one Z _ sel needs to be given by the Constant element, and the fifth switch K5, the sixth switch K6, the seventh switch K7 and the eighth switch K8 receive the signal through the From element, so that the fifth switch K5, the sixth switch K6, the seventh switch K7 and the eighth switch K8 can be simultaneously controlled. Similarly, Z _ sel ═ 1 indicates that the control switch is closed, and Z _ sel ═ 0 indicates that the control switch is open. Then, when the control signal Z _ sel ═ 1 is input to the fifth switch K5, the sixth switch K6, the seventh switch K7 and the eighth switch K8 at the same time through the main interface of the software, the third not gate N3 and the fourth not gate N4 convert the control signal into a control signal Z _ sel ═ 0 output, the sixth switch K6 and the eighth switch K8 are closed, the fifth switch K5 and the seventh switch K7 are opened, and the second impedance Z2 and the fourth impedance Z4 are connected; when the control signal of Z _ sel ═ 0 is input to the fifth switch K5, the sixth switch K6, the seventh switch K7 and the eighth switch K8 at the same time through the main interface of the software, the third not gate N3 and the fourth not gate N4 convert the control signal into Z _ sel ═ 1 output, then the fifth switch K5 and the seventh switch K7 are closed, the sixth switch K6 and the eighth switch K8 are opened, and the first impedance Z1 and the third impedance Z3 can be accessed. It should be understood that due to the closed state of the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4, when the fifth switch K5 and the seventh switch K7 are closed, there is actually only one access circuit in the first impedance Z1 and the third impedance Z3, and likewise, when the sixth switch K6 and the eighth switch K8 are closed, there is actually only one access circuit in the second impedance Z2 and the fourth impedance Z4.
Therefore, the simulation model for partial discharge detection has different characteristic parameters such as sensitivity and frequency band by accessing different impedances, so that the process of partial discharge detection under different conditions can be simulated, and the universality and the applicability of the simulation model for partial discharge detection are further enhanced.
In addition, in order to facilitate the collection of the relevant voltage signals in the detection process, voltage measuring elements M1 and M2 can be respectively connected in parallel to two ends of the first impedance assembly and the second impedance assembly so as to collect the voltage signals U1 and U2 of the two ends of the first impedance assembly and the second impedance assembly, and the voltage signals are summed by a summing element Add of a Matlab/Simulink software main interface and then output to a Goto element.
The embodiment of the invention can simulate and generate the partial discharge signal caused by the air gap defect. Specifically, in order to generate the partial discharge signal, as shown in fig. 3, the sample cell includes: a fourth terminal F2, a fifth terminal T, a first capacitor Cm1, a second capacitor Cm2, a third capacitor Cm3, a resistor Rg, a logic judgment component and a ninth switch K9. The fourth terminal F2 is used for electrical connection with the filtering unit 5. The fifth terminal T is used for electrical connection with the detection unit 6. Typically, the capacitance value of the first capacitor Cm1 is larger than the capacitance values of the second capacitor Cm2 and the third capacitor Cm3 by at least one order of magnitude or more. By adjusting the difference in capacitance between the first capacitor Cm1, the second capacitor Cm2, and the third capacitor Cm3, different air gap sizes can be simulated. For example, the larger the first capacitor Cm1 is compared to the second and third capacitors Cm2 and Cm3, the smaller the proportion of the area taken up by the simulated air gap in the direction perpendicular to the electric field; if the second capacitance Cm2 is larger than the third capacitance Cm3, the simulated air gap thickness ratio in the electric field direction is smaller. One plate of the first capacitor Cm1 is electrically connected to the fourth terminal F2 and one plate of the second capacitor Cm2, respectively. First, theThe other plate of a capacitor Cm1 is electrically connected to the fifth terminal T and a plate of the third capacitor Cm 3. The other plate of the second capacitor Cm2 is electrically connected to the other plate of the third capacitor Cm 3. The resistance of the resistor Rg is relatively small. For example, the resistance Rg has a value of about 106Omega. One end of the resistor Rg is electrically connected to a plate of the third capacitor Cm 3. The other end of the resistor Rg is electrically connected to one end of the ninth switch K9. The other end of the ninth switch K9 is electrically connected to the other plate of the third capacitor Cm 3. One end of the logic judgment component is electrically connected with the other plate of the third capacitor Cm 3. The other end of the logic judgment component is electrically connected with a signal input end of a ninth switch K9. And the logic judgment component is used for controlling the ninth switch K9 to be closed or opened according to the relation between the absolute value of the voltage at the two ends of the third capacitor Cm3 and the magnitude of the first threshold and the second threshold. The ninth switch K9 is an ideal switch. The first threshold is the air gap initiation discharge voltage. The second threshold is an extinguishing voltage.
Through the above structural design, the first capacitor Cm1, the second capacitor Cm2 and the third capacitor Cm3 may together simulate an insulating structure in which an air gap exists. The third capacitor Cm3 simulates an air gap in an insulation structure, the second capacitor Cm2 simulates an insulation medium connected in series with the air gap, and the first capacitor Cm1 simulates an insulation medium at other positions. When the ninth switch K9 is closed, the third capacitor Cm3 is equivalent to discharge through the resistor Rg, so that the air gap discharge process can be simulated; when the ninth switch K9 is open, the process of air gap discharge quenching can be simulated.
Specifically, the logic determination component includes: a voltage measuring element M3, an absolute value element Abs and a Relay element Relay. The input terminal of the voltage measuring element M3 is electrically connected to the other plate of the third capacitor Cm 3. The output of the voltage measuring element M3 is electrically connected to the input of the absolute value element Abs. The output of the absolute value element Abs is electrically connected to the input of the Relay element Relay, whose output is electrically connected to the signal input of the ninth switch K9.
The voltage measuring element M3 is used to acquire the voltage across the third capacitance Cm3 and input the acquired voltage to the absolute value element Abs. The absolute value element Abs is configured to input the received voltage to the Relay element Relay after taking an absolute value. The Relay element Relay is used to compare the absolute value of the received voltage with the magnitudes of the first threshold value and the second threshold value. If the absolute value of the voltage reaches the first threshold value from small to large, a signal for closing the ninth switch K9 is output to the ninth switch K9. If the absolute value of the voltage reaches the second threshold value from large to small, a signal for turning off the ninth switch K9 is output to the ninth switch K9. Specifically, the Relay element Relay outputs a signal of 1 indicating that the ninth switch K9 is closed, and outputs a signal of 0 indicating that the ninth switch K9 is opened.
In addition, in order to collect the voltage and current signals during the discharging process, the voltage measuring element M3 may input the collected voltage signal U3 to the Goto element of the Matlab/Simulink software main interface to collect the voltage. A current measuring element M4 is connected in series to the series circuit between the first capacitor Cm1 and the second capacitor Cm2, and is used for collecting a pulse current signal I during the discharge process, and directly inputting the collected pulse current signal I to a Goto element of a main interface of Matlab/Simulink software or inputting the pulse current signal to the Goto element of the main interface of the Matlab/Simulink software after the pulse current signal is gained by a signal gain element K connected in series.
Specifically, as shown in fig. 4, the power supply unit 1 includes: sixth terminal F3, seventh terminal SG, eighth terminal MG, alternating current power supply AC, voltage regulator T1, and test transformer T2. The alternating current source AC may be a 220kV or 380kV alternating current source. The sixth terminal F3 is used for electrical connection with the filter unit 5. The seventh terminal SG is used for electrical connection with the power source side disturbing unit 3. The eighth terminal MG is used for electrical connection with the ground network side interference unit 4. The low voltage side of the alternating current power supply AC is electrically connected to the seventh terminal SG. The high voltage side of the AC power source AC is electrically connected to the low voltage input side of the voltage regulator T1. The high voltage output side of the voltage regulator T1 is electrically connected to the low voltage input side of the test transformer T2. The high-voltage output side of the test transformer T2 is electrically connected to the sixth terminal F3. The voltage regulator T1 and the ground side of the test transformer T2 are both electrically connected to the eighth terminal MG.
Specifically, the power supply side interference unit 3 includes: a first signal generator G1 and a first controlled voltage supply VS 1. An output terminal of the first signal generator G1 is electrically connected to an input terminal of a first controlled voltage supply VS 1. An output terminal of the first controlled voltage power source VS1 is electrically connected to the seventh terminal SG. The first controlled voltage supply VS1 is connected to ground. For example, the first signal generator G1 may be a gaussian noise signal generator.
Through the above structural design, a specific interference signal source can be configured by adjusting parameters of the first signal generator G1 and the first controlled voltage power source VS1 according to a desired interference waveform or mathematical expression.
Specifically, the ground grid side interference unit 4 includes: a second signal generator G2 and a second controlled voltage supply VS 2. An output terminal of the second signal generator G2 is electrically connected to an input terminal of a second controlled voltage supply VS 2. An output terminal of the second controlled-voltage power source VS2 is electrically connected to the third terminal G and the eighth terminal MG, respectively. The second controlled voltage supply VS2 is connected to ground. For example, the second signal generator G2 may be a gaussian noise signal generator.
Through the above structural design, a specific interference signal source can be configured by adjusting the parameters of the second signal generator G2 and the second controlled voltage power source VS2 according to a required interference waveform or mathematical expression.
Specifically, the filtering unit 5 may build a suitable circuit according to the requirement. The filter unit 5 is, for example, an RLC circuit structure or an RL circuit structure.
No matter the test sample unit 2 or the detection unit 6, the collected voltage and current can be displayed through a Scope oscilloscope element of a Matlab/Simulink software main interface.
In summary, the simulation model for partial discharge detection in the embodiment of the present invention has strong universality and applicability, provides an experimental simulation platform for the research of interference signal propagation on the power supply side/ground grid side of the partial discharge detection loop, realizes the accurate simulation of the propagation characteristic of the partial discharge signal in the circuit caused by air gap defect, and, accurate simulation of the propagation characteristics of the partial discharge signal in the circuit after the power supply side and the ground network side interference signals are added, the series or parallel connection relation between the impedance of the detection unit and the test sample unit can be selected according to the actual situation, the type of the impedance can be selected, the parameters of each element can be set according to the actual requirement, and the simulation waveform of the simulation model is output in real time, and the specific characteristics and suppression measures of the interference signal propagation at the power supply side/ground grid side of the partial discharge detection loop can be further researched by utilizing the simulation result.
The embodiment of the invention also discloses a simulation method for partial discharge detection. As shown in fig. 5, the simulation method includes the following steps:
step S501: and establishing a simulation model for partial discharge detection through Matlab/Simulink software.
The simulation model for partial discharge detection is the simulation model of the above embodiment, and is not described herein again.
Step S502: and setting parameters of a simulation model for partial discharge detection.
Specifically, according to actual equipment to be adopted in a test, relevant parameters of an alternating current power supply, a voltage regulator and a test transformer of a power supply unit are respectively set; setting relevant parameters of impedance in the detection unit; setting relevant parameters of each capacitor in the test sample unit and parameters such as a first threshold value, a second threshold value and the like of the relay element; and setting values of SP _ sel and Z _ sel in a main software interface. Parameters of the first signal generator and the first controlled voltage power supply of the power supply side interference unit, and parameters of the second signal generator and the second controlled voltage power supply are set according to a waveform or a mathematical expression of an interference signal that may exist. And setting parameters such as the type of a solver, the solving step length, the simulation time and the like of software according to the characteristics of signals such as interference signals and the like.
For example, the voltage of an ac power supply is 380V, the transformation ratio of a test transformer is 250kV/250V, the voltage applied to a sample cell required for partial discharge detection is 50kV, and the transformation ratio of a regulator is 50/380.
Step S503: and simulating the detection of the partial discharge signal by adopting a simulation model of the partial discharge detection.
Specifically, the steps include the following processes:
(1) and controlling the power supply unit to supply power, and generating interference signals by the power supply side interference unit and the ground grid side interference unit.
Fig. 10 shows a waveform of a voltage to ground output from the power supply module. Fig. 11 shows the situation that the voltage waveform to ground is subjected to fourier transform (FFT) to obtain each harmonic.
(2) And controlling the on-off of a ninth switch of the test sample unit to simulate an air gap discharge process or a discharge extinction process.
For example, assuming that the voltage loaded on the sample cell is 50KV, the initial discharge voltage of the sample cell is 23.8KV, i.e. the first threshold is 23.8KV, and the discharge extinction voltage is 18.28KV, i.e. the second threshold is 18.28KV, calculated according to the existing formula. When the voltage applied to the third capacitor is compared with a set first threshold value after the absolute value element takes the absolute value, after the first threshold value is exceeded, the relay element outputs a signal '1', so that the ninth switch is closed, after the ninth switch is closed, the third capacitor is connected with the resistor in parallel, the impedance on the air gap is reduced, further, the voltage on the air gap is reduced, when the absolute value is reduced to the second threshold value, the relay element outputs a signal '0', so that the ninth switch is opened, the impedance on the air gap is increased, further, the voltage on the air gap is increased. Fig. 12 shows the voltage (air gap voltage) and the discharge pulse waveform of the third capacitor obtained by simulation in the present invention, where a is the air gap voltage waveform and B is the discharge pulse waveform.
(3) And controlling the on-off of a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch and an eighth switch of the detection unit to simulate the detection of the partial discharge signal when one end of the test sample unit is grounded or when two ends of the test sample unit are grounded.
After the partial discharge occurs, the partial discharge signal will flow into the detection unit, and the detection unit is divided into two systems in total, one is the series connection of the impedance and the test sample unit, and the other is the parallel connection of the impedance and the test sample unit, and the two systems are switched through the SP _ sel signal incoming line in the main interface. The impedance in each system is divided into two types, for example, a preferred embodiment of the present invention is RLC type and RC type, respectively, and switching is performed through the Z _ sel signal in the main interface, so that corresponding matching can be performed according to different use scenarios, and the parameters of the impedance can be adjusted accordingly.
Specifically, the on/off of the switch has the following four conditions:
the first switch, the third switch and the fifth switch are controlled to be closed, the first impedance and the coupling capacitor form a first series circuit, the test sample unit is connected in parallel to two ends of the first series circuit, and simulation of detection of a partial discharge signal when one end of the test sample unit is grounded is performed.
Specifically, it can be realized by SP _ sel ═ 0 and Z _ sel ═ 0. The current path is shown as a bold line in fig. 6.
And controlling the first switch, the third switch and the sixth switch to be closed, so that the second impedance and the coupling capacitor form a second series circuit, connecting the test sample unit in parallel at two ends of the second series circuit, and simulating the detection of the partial discharge signal when one end of the test sample unit is grounded.
Specifically, it can be realized by SP _ sel ═ 0 and Z _ sel ═ 1. The current path is shown as a bold line in fig. 7.
And controlling the second switch, the fourth switch and the seventh switch to be closed, so that the third impedance and the test sample unit form a third series circuit, and the coupling capacitor is connected in parallel at two ends of the third series circuit to simulate the detection of the partial discharge signal when two ends of the test sample unit are not grounded.
Specifically, it can be realized by SP _ sel ═ 1 and Z _ sel ═ 0. The current path is shown as a bold line in fig. 8.
And controlling the second switch, the fourth switch and the eighth switch to be closed, so that the fourth impedance and the test sample unit form a fourth series circuit, and the coupling capacitor is connected in parallel at two ends of the fourth series circuit to simulate the detection of the partial discharge signal when two ends of the test sample unit are not grounded.
Specifically, it can be realized by SP _ sel ═ 1 and Z _ sel ═ 1. The current path is shown as a bold line in fig. 9.
Through the process, the power supply side interference unit outputs interference signals to the power supply unit to enable the power supply unit to achieve power supply output containing the interference signals, the signals output by the power supply enter the test sample unit through the filtering unit, partial discharge caused by air gap defects is simulated through the test sample unit, the partial discharge signals flow into impedance of the interference signals containing the ground grid side interference unit again, waveforms are output in real time through the oscilloscope, the simulation process of partial discharge detection after the power supply side interference signals and the ground grid side interference signals are added is achieved, and voltage signals, pulse current signals and voltage signals of impedance from the detection unit, which are collected in the simulation process, at two ends of a third capacitor of the test sample unit can be output. By analyzing the waveforms of these signals, the propagation characteristics of the interfering signals can be studied; the amplitudes of the interference signal and the local discharge signal can be obtained by means of adjusting parameters of the filtering unit and the like, so that the parameters of the filtering unit corresponding to the amplitude of the interference signal with smaller amplitude relative to the local discharge signal can be selected to guide the construction of actual equipment.
For example, when the filter unit is not used, the voltage waveform across the impedance of the detection unit connected to the circuit obtained by Matlab/Simulink software is shown in fig. 13, and the corresponding FFT analysis result is shown in fig. 14. As can be seen from a comparison of fig. 11 and 14, the low-band component within 20kHz is significantly reduced after the harmonic interference reaches the impedance connected to the circuit. The amplitude of the interference signal coupled to the impedance of the circuit is about 1/2% of the amplitude of the partial discharge signal, and The Harmonic Distortion (THD) is also as high as 251.93%.
When R is 500. omega. and L is 1X 10-3For the H filter unit, the voltage waveform of the impedance connected to the circuit and the corresponding FFT analysis result are shown in fig. 15 and 16, and it can be seen that the amplitude of the interference component in the signal is significantly reduced to below 1/3 of the amplitude of the partial discharge signal, and the THD is also reduced to 169.26%.
When the filter unit with R2000 Ω and L0.1H is used, the voltage waveform across the impedance of the connected circuit and the corresponding FFT analysis result are shown in fig. 17 and 18. At this time, the amplitude of the interference component in the signal further decreases to 1/4 or less of the amplitude of the partial discharge signal, and THD also decreases to 85.21%.
Comparing the three schemes, the third scheme can obviously reduce the interference component in the impedance connected into the circuit, improve the identification rate of the detection result of the partial discharge signal, and is particularly beneficial to more accurately identifying the partial discharge signal in the test sample unit under the condition that the partial discharge signal is weaker.
To sum up, the simulation method for partial discharge detection according to the embodiment of the present invention adopts the simulation model for partial discharge detection with strong versatility and applicability of the foregoing embodiment, so as to achieve accurate simulation of propagation characteristics of a partial discharge signal in a circuit caused by an air gap defect, and accurate simulation of propagation characteristics of a partial discharge signal in a circuit after power supply side and ground grid side interference signals are added, and may select a series or parallel relationship between impedance of a detection unit and a test sample unit according to an actual situation, select a type of the impedance, set parameters of each element according to an actual requirement, and output a simulation waveform of the simulation model in real time, and may further study specific characteristics and suppression measures of propagation of the power supply side/ground grid side interference signals of the partial discharge detection circuit by using a simulation result.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (8)
1. A simulation model for partial discharge detection is established by Matlab/Simulink software, and comprises: the device comprises a power supply unit for supplying power, a test article unit for simulating partial discharge, a power supply side interference unit for simulating a power supply side interference signal, a ground grid side interference unit for simulating a ground grid side interference signal, a filtering unit for filtering and a detection unit for detecting a partial discharge signal; the power supply unit is electrically connected with the power supply side interference unit, the ground grid side interference unit, the filtering unit and the detection unit respectively, the test sample unit is electrically connected with the filtering unit and the detection unit respectively, and the detection unit is also electrically connected with the filtering unit;
wherein the detection unit includes: the circuit comprises a first terminal, a second terminal, a third terminal, a coupling capacitor, a first impedance component, a second impedance component, a first switch, a second switch, a third switch and a fourth switch, wherein when the first switch and the third switch are closed, the second switch and the fourth switch are opened; or, when the second switch and the fourth switch are closed, the first switch and the third switch are disconnected;
the first terminal is used for being electrically connected with the filtering unit, the second terminal is used for being electrically connected with the test sample unit, and the third terminal is used for being electrically connected with the earth screen side interference unit;
one polar plate of the coupling capacitor is electrically connected with the first terminal, the other polar plate of the coupling capacitor is electrically connected with one end of the first switch and one end of the second switch respectively, the other end of the first switch is electrically connected with one end of the first impedance component, and the other end of the second switch is electrically connected with the third terminal;
one ends of the third switch and the fourth switch are respectively electrically connected with the second terminal, the other end of the third switch is electrically connected with the third terminal, and the other end of the fourth switch is electrically connected with one end of the second impedance component;
the third terminal is electrically connected with the other end of the first impedance component and the other end of the second impedance component respectively;
the first impedance component includes: a fifth switch, a sixth switch, a first impedance, and a second impedance; the second impedance component includes: a seventh switch, an eighth switch, a third impedance, and a fourth impedance; the first impedance and the third impedance are of the same type, and the second impedance and the fourth impedance are of the same type; when the fifth switch and the seventh switch are closed, the sixth switch and the eighth switch are opened; or, when the sixth switch and the eighth switch are closed, the fifth switch and the seventh switch are opened;
the other end of the first switch is electrically connected with one end of the fifth switch and one end of the sixth switch respectively;
the other end of the fourth switch is electrically connected with one end of the seventh switch and one end of the eighth switch respectively;
one end of the first impedance is electrically connected with the other end of the fifth switch, and the other end of the first impedance is electrically connected with the third terminal;
one end of the second impedance is electrically connected with the other end of the sixth switch, and the other end of the second impedance is electrically connected with the third terminal;
one end of the third impedance is electrically connected with the other end of the seventh switch, and the other end of the third impedance is electrically connected with the third terminal;
one end of the fourth impedance is electrically connected with the other end of the eighth switch, and the other end of the fourth impedance is electrically connected with the third terminal;
the sample unit includes: the circuit comprises a fourth terminal, a fifth terminal, a first capacitor, a second capacitor, a third capacitor, a resistor, a logic judgment component and a ninth switch;
the fourth terminal is used for being electrically connected with the filtering unit, and the fifth terminal is used for being electrically connected with the detection unit;
one polar plate of the first capacitor is electrically connected with the fourth terminal and one polar plate of the second capacitor respectively, and the other polar plate of the first capacitor is electrically connected with the fifth terminal and one polar plate of the third capacitor respectively;
the other polar plate of the second capacitor is electrically connected with the other polar plate of the third capacitor;
one end of the resistor is electrically connected with one polar plate of the third capacitor, the other end of the resistor is electrically connected with one end of the ninth switch, and the other end of the ninth switch is electrically connected with the other polar plate of the third capacitor;
one end of the logic judgment component is electrically connected with the other pole plate of the third capacitor, the other end of the logic judgment component is electrically connected with the signal input end of the ninth switch, and the logic judgment component is used for controlling the ninth switch to be switched on or switched off according to the magnitude relation between the absolute value of the voltage at the two ends of the third capacitor and the first threshold and the second threshold.
2. The simulation model of claim 1, wherein the logic determination component comprises: a voltage measuring element, an absolute value element and a relay element; the input end of the voltage measuring element is electrically connected with the other polar plate of the third capacitor, the output end of the voltage measuring element is electrically connected with the input end of the absolute value element, the output end of the absolute value element is electrically connected with the input end of the relay element, and the output end of the relay element is electrically connected with the signal input end of the ninth switch;
the voltage measuring element is used for collecting voltages at two ends of the third capacitor and inputting the collected voltages into the absolute value element, the absolute value element is used for inputting the received absolute values of the voltages into the relay element, the relay element is used for comparing the received absolute values of the voltages with the first threshold value and the second threshold value, if the absolute values of the voltages reach the first threshold value from small to large, a signal for closing the ninth switch is output to the ninth switch, and if the absolute values of the voltages reach the second threshold value from large to small, a signal for opening the ninth switch is output to the ninth switch.
3. A simulation method for partial discharge detection is characterized by comprising the following steps:
establishing a simulation model of the partial discharge detection according to any one of claims 1-2 by Matlab/Simulink software;
setting parameters of a simulation model of the partial discharge detection;
and simulating the detection of the partial discharge signal by adopting the simulation model for the partial discharge detection.
4. The simulation method according to claim 3, wherein the step of simulating the detection of the partial discharge signal using the simulation model of the partial discharge detection comprises:
controlling the power supply unit to supply power, wherein the power supply side interference unit and the ground network side interference unit generate interference signals;
controlling the on-off of a ninth switch of the test sample unit, and simulating an air gap discharge process or a discharge extinction process;
and controlling the on-off of a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch and an eighth switch of the detection unit to simulate the detection of the partial discharge signal when one end of the test sample unit is grounded or when both ends of the test sample unit are not grounded.
5. The simulation method according to claim 4, wherein the step of performing simulation of detection of the partial discharge signal when one end of the sample unit is grounded or when both ends of the sample unit are not grounded comprises:
and controlling the first switch, the third switch and the fifth switch to be closed, so that the first impedance and the coupling capacitor form a first series circuit, the test sample unit is connected in parallel at two ends of the first series circuit, and simulation of detection of a partial discharge signal is performed when one end of the test sample unit is grounded.
6. The simulation method according to claim 4, wherein the step of performing simulation of detection of the partial discharge signal when one end of the sample unit is grounded or when both ends of the sample unit are not grounded comprises:
and controlling the first switch, the third switch and the sixth switch to be closed, so that the second impedance and the coupling capacitor form a second series circuit, and the test sample unit is connected in parallel at two ends of the second series circuit to simulate the detection of a partial discharge signal when one end of the test sample unit is grounded.
7. The simulation method according to claim 4, wherein the step of performing simulation of detection of the partial discharge signal when one end of the sample unit is grounded or when both ends of the sample unit are not grounded comprises:
and controlling the second switch, the fourth switch and the seventh switch to be closed, so that the third impedance and the test sample unit form a third series circuit, and the coupling capacitor is connected in parallel at two ends of the third series circuit to simulate the detection of the partial discharge signal when two ends of the test sample unit are not grounded.
8. The simulation method according to claim 4, wherein the step of performing simulation of detection of the partial discharge signal when one end of the sample unit is grounded or when both ends of the sample unit are not grounded comprises:
and controlling the second switch, the fourth switch and the eighth switch to be closed, so that the fourth impedance and the test sample unit form a fourth series circuit, and the coupling capacitor is connected in parallel at two ends of the fourth series circuit to simulate the detection of the partial discharge signal when two ends of the test sample unit are not grounded.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007028977A1 (en) * | 2005-09-05 | 2007-03-15 | University Court Of Glasgow Caledonian University | High voltage insulation monitoring sensor |
| CN201373905Y (en) * | 2009-03-04 | 2009-12-30 | 厦门红相电力设备股份有限公司 | Safety detecting evaluation system of power cable |
| CN102508124A (en) * | 2011-10-18 | 2012-06-20 | 广西电网公司电力科学研究院 | Detection method of partial discharge of electrical equipment and device thereof |
| CN102759692A (en) * | 2012-07-24 | 2012-10-31 | 广州供电局有限公司 | Simulation method for detecting local discharge of switch cabinet based on virtual reality technology |
| CN103954890A (en) * | 2014-04-10 | 2014-07-30 | 国家电网公司 | DC partial discharge detection device and method for converter transformer |
| CN105389423A (en) * | 2015-10-22 | 2016-03-09 | 云南电网有限责任公司电力科学研究院 | Matlab / Simulink based power cable partial discharge signal propagation simulation method |
| CN107797033A (en) * | 2017-09-29 | 2018-03-13 | 广西电网有限责任公司电力科学研究院 | A kind of detection platform to analogue transformer partial discharge test |
| CN109946575A (en) * | 2019-03-20 | 2019-06-28 | 天津大学 | Based on the intermediate joint of electric cable partial discharge detecting system under compound field |
-
2019
- 2019-12-05 CN CN201911236247.2A patent/CN111025099B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007028977A1 (en) * | 2005-09-05 | 2007-03-15 | University Court Of Glasgow Caledonian University | High voltage insulation monitoring sensor |
| CN201373905Y (en) * | 2009-03-04 | 2009-12-30 | 厦门红相电力设备股份有限公司 | Safety detecting evaluation system of power cable |
| CN102508124A (en) * | 2011-10-18 | 2012-06-20 | 广西电网公司电力科学研究院 | Detection method of partial discharge of electrical equipment and device thereof |
| CN102759692A (en) * | 2012-07-24 | 2012-10-31 | 广州供电局有限公司 | Simulation method for detecting local discharge of switch cabinet based on virtual reality technology |
| CN103954890A (en) * | 2014-04-10 | 2014-07-30 | 国家电网公司 | DC partial discharge detection device and method for converter transformer |
| CN105389423A (en) * | 2015-10-22 | 2016-03-09 | 云南电网有限责任公司电力科学研究院 | Matlab / Simulink based power cable partial discharge signal propagation simulation method |
| CN107797033A (en) * | 2017-09-29 | 2018-03-13 | 广西电网有限责任公司电力科学研究院 | A kind of detection platform to analogue transformer partial discharge test |
| CN109946575A (en) * | 2019-03-20 | 2019-06-28 | 天津大学 | Based on the intermediate joint of electric cable partial discharge detecting system under compound field |
Non-Patent Citations (4)
| Title |
|---|
| 固体绝缘气隙局部放电模型构建与仿真研究;李锰等;《电磁避雷器》;20130430;第2013卷(第2期);全文 * |
| 基于等离子体模型的气隙局部放电分析及仿真研究;陈友福等;《电磁避雷器》;20161231;第2016卷(第6期);全文 * |
| 宁夏电网GIS常见故障及典型案例分析;周秀等;《宁夏电力》;20180628;第2018卷(第3期);全文 * |
| 气隙局部放电模型改进及仿真;丁然等;《高电压技术》;20161231;第42卷(第12期);全文 * |
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