CN111562475B - Variable frequency power supply partial discharge detection circuit for high-voltage test and evaluation method - Google Patents
Variable frequency power supply partial discharge detection circuit for high-voltage test and evaluation methodInfo
- Publication number
- CN111562475B CN111562475B CN202010520788.4A CN202010520788A CN111562475B CN 111562475 B CN111562475 B CN 111562475B CN 202010520788 A CN202010520788 A CN 202010520788A CN 111562475 B CN111562475 B CN 111562475B
- Authority
- CN
- China
- Prior art keywords
- power supply
- frequency power
- variable frequency
- variable
- partial discharge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 28
- 238000011156 evaluation Methods 0.000 title claims abstract description 7
- 238000010998 test method Methods 0.000 title description 2
- 238000000034 method Methods 0.000 claims abstract description 3
- 238000002955 isolation Methods 0.000 claims description 20
- 239000003990 capacitor Substances 0.000 claims description 11
- 230000008878 coupling Effects 0.000 claims description 11
- 238000010168 coupling process Methods 0.000 claims description 11
- 238000005859 coupling reaction Methods 0.000 claims description 11
- 239000013307 optical fiber Substances 0.000 claims description 4
- 230000008054 signal transmission Effects 0.000 claims description 3
- 238000004804 winding Methods 0.000 claims description 3
- 230000032683 aging Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
Abstract
The invention discloses a circuit and a method for detecting and evaluating partial discharge capacity of a variable-frequency power supply for high-voltage test, and solves the problem of how to detect and evaluate the partial discharge capacity of the variable-frequency power supply for high-voltage test. Starting a test loop, adjusting the output frequency of the variable frequency power supply (3) to be 300Hz at maximum, and adjusting the output voltage of the variable frequency power supply (3) with 5 volts as a step until the output voltage reaches 350 volts at maximum; gradually reducing the impedance value in the variable load device (10) to 0.30648 Ω, keeping the power factor angle at 0 o, and recording the local discharge amount Δq 1 of the local discharge detector (20) at the time when the output current of the variable frequency power supply is the maximum value; the output voltage of the variable frequency power supply is reduced and disconnected through a variable frequency power supply control box (5); calculating the discharge quantity Q 1 of the variable frequency power supply by using the following formula; and evaluating the variable frequency power supply according to the discharge quantity. The quality detection and evaluation of the variable frequency power supply are realized.
Description
Technical Field
The invention relates to a circuit for detecting partial discharge of a variable frequency power supply for high-voltage test, in particular to a circuit for detecting partial discharge of a variable frequency power supply for high-voltage test and an evaluation method.
Background
The variable frequency power supply is main control power supply equipment used in a field high-voltage test, and converts a 380V overhaul power supply commonly used in the field into a test power supply with adjustable voltage and frequency; at present, the variable frequency power supply has high price and uneven quality, the product technology is still immature, and the phenomena of damage and insulation aging of electronic devices with different degrees can occur in the variable frequency power supply after the variable frequency power supply is used for about 5 years; the local discharge capacity of the variable frequency power supply is an index which can best reflect the performance of the variable frequency power supply, and how to detect and evaluate the local discharge capacity of the variable frequency power supply is a technical problem which needs to be solved in the field.
Disclosure of Invention
The invention provides a circuit and a method for detecting and evaluating the partial discharge capacity of a variable-frequency power supply for a high-voltage test, which solve the technical problem of how to detect and evaluate the partial discharge capacity of the variable-frequency power supply for the high-voltage test.
The invention solves the technical problems by the following technical proposal:
The variable-frequency power supply partial discharge detection circuit for the high-voltage test comprises a 380V power supply system, a detected variable-frequency power supply, a variable-frequency power supply control box, a current transformer, a variable load device, a partial discharge isolation transformer, a voltage divider, a high-voltage peak value meter, a coupling capacitor, detection impedance, a grounding terminal and a partial discharge analyzer, wherein the 380V power supply system is connected with the input end of the detected variable-frequency power supply through a low-voltage input cable, the output end of the detected variable-frequency power supply is connected with the low-voltage input side of the partial discharge isolation transformer through a low-voltage output cable, the variable load device is connected with the input end of the partial discharge isolation transformer in parallel, a primary winding of the current transformer is connected in series in an output loop of the variable-frequency power supply, the high-voltage output head end of the partial discharge isolation transformer is respectively connected with the high-voltage end of the voltage divider and the head end of the coupling capacitor through a corona-free pressurizing line, the tail end of the coupling capacitor is connected with the input end of the detection impedance, and the ground end of the partial discharge isolation transformer and the detection impedance are connected with the grounding terminal through a grounding shielding line; the voltage divider is connected with the high-voltage peak value meter through a coaxial cable, and the partial discharge analyzer is connected with the detection impedance through the coaxial cable; the detected variable frequency power supply is connected with the variable frequency power supply control box through the control optical fiber.
The evaluation method of the variable frequency power supply partial discharge detection circuit for the high voltage test comprises the following steps:
Firstly, using a standard pulse generator to generate a local amplified signal with the discharge capacity of 10PC and the frequency of 50Hz, inputting the signal to a high-voltage end of a coupling capacitor, and calibrating the local discharge capacity of the test loop through a local discharge analyzer;
Secondly, using a standard pulse generator to generate a local amplified signal with the discharge capacity of 10PC and the frequency of 50Hz, inputting the signal to a low-voltage end of a non-local discharge isolation transformer, measuring a local discharge capacity signal Q 0 by a local discharge analyzer, and calculating to obtain a local discharge capacity signal transmission ratio k, wherein k=Q 0/10;
Thirdly, adjusting the load value in the variable load device to a maximum value of 10Ω, and making the power factor angle be 0 o;
Step four, starting a test loop, adjusting the output frequency of the variable-frequency power supply to be 300Hz at maximum, and adjusting the output voltage of the variable-frequency power supply by taking 5 volts as a step until the output voltage reaches 350 volts at maximum;
Step five, gradually reducing the impedance value in the variable load device to 0.30648 Ω, keeping the power factor angle to be 0 o, wherein the output current of the variable frequency power supply is 1142 amperes at the maximum value, and recording the local discharge quantity delta Q 1 of the local discharge detector at the moment;
step six, reducing and disconnecting the output voltage of the variable frequency power supply through a variable frequency power supply control box; calculating the discharge quantity Q 1：Q1=ΔQ1/k=10ΔQ1/Q0 of the variable frequency power supply by using the following formula;
Seventh, through adjusting the load resistance-capacitance inductance ratio in the variable load device, the impedance value is 0.30648 Ω, the power factor angle is 45 o, and the steps from the fourth step to the sixth step are repeated, so as to obtain the discharge quantity Q 2 under the working condition;
Eighth, by adjusting the load resistance-capacitance inductance ratio in the variable load device, the impedance value is 0.30648 Ω, the power factor angle is 90 o, and the steps from the fourth step to the sixth step are repeated, so as to obtain the discharge quantity Q 3 under the working condition;
Ninth, the resistance-capacitance inductance ratio of the load in the variable load device is adjusted to enable the resistance value to be 0.30648 omega and the power factor angle to be-45 o, and the steps from the fourth step to the sixth step are repeated to obtain the discharge quantity Q 4 under the working condition;
Tenth, by adjusting the load resistance-capacitance inductance ratio in the variable load device, the impedance value is 0.30648 Ω, the power factor angle is-90 o, and the steps from the fourth step to the sixth step are repeated, so as to obtain the discharge quantity Q 5 under the working condition;
The eleventh step, defining the maximum value of the discharge quantity Q 1, the discharge quantity Q 2, the discharge quantity Q 3, the discharge quantity Q 4 and the discharge quantity Q 5 as a final assessment index quantity Q of the partial discharge quantity of the variable-frequency power supply, namely Q=max [ Q 1、Q2、Q3、Q4、Q5 ];
Twelfth, if Q is larger than or equal to 21, defining the detected variable-frequency power supply as a failure grade; if the Q is less than or equal to 11 and less than or equal to 20, defining the detected variable frequency power supply as a qualified grade; if the Q is less than or equal to 6 and less than or equal to 10, defining the detected variable frequency power supply as a good grade; if Q is less than or equal to 5, defining the tested variable frequency power supply as an excellent grade.
The invention is practical and simple, realizes the detection of potential fault factors of the variable frequency power supply by detecting the partial discharge capacity of the variable frequency power supply under various working conditions, realizes the quality detection work of the variable frequency power supply for the first time, improves the equipment reliability level and ensures the safe and reliable operation of the power grid.
Drawings
FIG. 1 is a schematic diagram of a test circuit according to the present invention.
Detailed Description
The invention is described in detail below with reference to the attached drawing figures:
The utility model provides a variable frequency power supply partial discharge volume detection circuit for high voltage test, including 380V electrical power generating system 1, the variable frequency power supply 3 of being examined, variable frequency power supply control box 5, current transformer 7, variable load device 8, no partial discharge isolation transformer 9, divider 12, high voltage peak value table 13, coupling capacitor 14, detect impedance 15, ground terminal 16 and partial discharge analyzer 18, 380V electrical power generating system 1 links together with the input of being examined variable frequency power supply 3 through low voltage input cable 2, the output of being examined variable frequency power supply 3 links together with the low voltage input side of no partial discharge isolation transformer 9 through low voltage output cable 6, the variable frequency power supply 3 of being examined can become voltage and frequency adjustable single-phase power supply with three-phase power supply, no partial discharge isolation transformer 9 changes low voltage input into high voltage output; the variable load device 8 is connected in parallel with the input end of the isolation transformer 9 without partial discharge, the primary winding of the current transformer 7 is connected in series in the output loop of the variable frequency power supply 3 and used for monitoring the output current of the variable frequency power supply 3, the high voltage output head end of the isolation transformer 9 without partial discharge is respectively connected with the high voltage end of the voltage divider 12 and the head end of the coupling capacitor 14 through the corona-free pressurizing line 10, the corona-free pressurizing line 10 adopts a corona-free wire with a wire core of 4 square millimeters, the tail end of the coupling capacitor 14 is connected with the input end of the detection impedance 15, and the high voltage output tail end of the isolation transformer 9 without partial discharge, the ground end of the voltage divider 12 and the ground end of the detection impedance 15 are connected with the ground terminal 16 through the ground shielding line 11; the voltage divider 12 is connected with the high-voltage peak value table 13 through a coaxial cable, and the partial discharge analyzer 18 is connected with the detection impedance 15 through a coaxial cable 17; the detected variable frequency power supply 3 is connected with the variable frequency power supply control box 5 through the control optical fiber 4, and the accuracy of the test output voltage is ensured by checking the high-voltage display on the high-voltage peak value meter 13 and the voltage display on the variable frequency power supply control box 5; the control optical fiber 4 is connected with the variable frequency power supply control box 5, so that the output voltage and the frequency are remotely controlled, and meanwhile, the low voltage and the high voltage are thoroughly isolated.
A detection evaluation method of a variable frequency power supply partial discharge detection circuit for a high voltage test comprises the following steps:
firstly, using a standard pulse generator to generate a local amplified signal with the discharge capacity of 10PC and the frequency of 50Hz, inputting the signal to a high-voltage end of a coupling capacitor 14, and calibrating the local discharge capacity of the test loop through a local discharge analyzer 18;
secondly, using a standard pulse generator to generate a local amplified signal with the discharge capacity of 10PC and the frequency of 50Hz, inputting the signal to a low-voltage end of the isolation transformer 9 without partial discharge, measuring a local discharge capacity signal Q 0 by a local discharge analyzer 18, and calculating to obtain a local discharge capacity signal transmission ratio k, wherein k=Q 0/10;
Thirdly, adjusting the load value in the variable load device 8 to the maximum value 10Ω, and making the power factor angle be 0 o;
Step four, starting a test loop, adjusting the output frequency of the variable-frequency power supply 3 to be 300Hz at maximum, and adjusting the output voltage of the variable-frequency power supply 3 by taking 5 volts as a step until the output voltage reaches 350 volts at maximum;
Step five, gradually reducing the impedance value in the variable load device 10 to 0.30648 Ω, and keeping the power factor angle at 0 o, wherein the output current of the variable frequency power supply 3 is the maximum value 1142A, and recording the local discharge amount Δq 1 of the local discharge detector 20 at this time;
Step six, reducing and disconnecting the output voltage of the variable frequency power supply 3 through the variable frequency power supply control box 5; calculating the discharge quantity Q 1：Q1=ΔQ1/k=10ΔQ1/Q0 of the variable frequency power supply 3 by using the following formula;
Seventh, through adjusting the load resistance-capacitance ratio in the variable load device (10), the impedance value is 0.30648 Ω, the power factor angle is 45 o, and the steps from the fourth step to the sixth step are repeated, so as to obtain the discharge quantity Q 2 under the working condition;
Eighth, by adjusting the ratio of the resistance-capacitance inductance of the load in the variable load device 10 to make the impedance value be 0.30648 Ω and the power factor angle be 90 o, repeating the steps from the fourth step to the sixth step to obtain the discharge quantity Q 3 under the working condition;
Ninth, by adjusting the ratio of the resistance-capacitance inductance of the load in the variable load device 10 to make the impedance value be 0.30648 Ω and the power factor angle be-45 o, repeating the steps from the fourth step to the sixth step to obtain the discharge quantity Q 4 under the working condition;
Tenth, by adjusting the ratio of the resistance-capacitance inductance of the load in the variable load device 10 to make the impedance value be 0.30648 Ω and the power factor angle be-90 o, repeating the steps from the fourth step to the sixth step to obtain the discharge quantity Q 5 under the working condition;
The eleventh step, defining the maximum value of the discharge quantity Q 1, the discharge quantity Q 2, the discharge quantity Q 3, the discharge quantity Q 4 and the discharge quantity Q 5 as a final assessment index quantity Q of the partial discharge quantity of the variable-frequency power supply (3), namely Q=max [ Q 1、Q2、Q3、Q4、Q5 ];
Twelfth, if Q is larger than or equal to 21, defining the detected variable frequency power supply 3 as a failure grade; if the Q is less than or equal to 11 and less than or equal to 20, defining the detected variable frequency power supply 3 as a qualified grade; if the Q is less than or equal to 6 and less than or equal to 10, defining the detected variable frequency power supply 3 as a good grade; if Q is less than or equal to 5, the detected variable frequency power supply 3 is defined as an excellent grade.
The detection environment is required to be in a fully sealed state, no wind gust exists, the detection environment temperature and humidity are constant, the surrounding power supply environment is good, and the detection environment and the power supply quality data are kept unchanged for the past time; after the test loop is started, the operation modes of the detected variable frequency power supply 3 under different working conditions are simulated by adjusting various proportion combinations of the internal resistance, the inductance and the capacitance of the variable load device 8, and the most representative 5 operation working conditions are selected, so that the local discharge capacity of the variable frequency power supply under various operation modes is obtained. Classifying and judging the partial discharge capacity of the detected variable frequency power supply according to a judging standard; the comprehensive performance quality of the variable frequency power supply is evaluated in a grading mode, and networking detection work aiming at the variable frequency power supply is effectively conducted.
Claims (1)
1. The evaluation method of the variable frequency power supply partial discharge detection circuit for the high voltage test is carried out by the variable frequency power supply partial discharge detection circuit for the high voltage test, the variable frequency power supply partial discharge detection circuit for the high voltage test comprises a 380V power supply system (1), a detected variable frequency power supply (3), a variable frequency power supply control box (5), a current transformer (7), a variable load device (8), an isolation transformer without partial discharge (9), a voltage divider (12), a high voltage peak value meter (13), a coupling capacitor (14), a detection impedance (15), a grounding terminal (16) and a partial discharge analyzer (18), the 380V power supply system (1) is connected with the input end of the detected variable frequency power supply (3) through a low voltage input cable (2), the output end of the detected variable load device (8) is connected with the low voltage input side of the isolation transformer without partial discharge (9) in parallel, the primary winding of the variable load device (7) is connected with the output end of the isolation transformer (9) in series through a low voltage output cable (6), the output end of the isolation transformer (9) without partial discharge is connected with the high voltage loop (12) in series through the high voltage input end of the isolation transformer (14) with the high voltage loop (12), the tail end of the coupling capacitor (14) is connected with the input end of the detection impedance (15), and the high-voltage output tail end of the partial discharge-free isolation transformer (9), the ground end of the voltage divider (12) and the ground end of the detection impedance (15) are connected with the ground terminal (16) through the ground shielding line (11); the voltage divider (12) is connected with the high-voltage peak value meter (13) through a coaxial cable, and the partial discharge analyzer (18) is connected with the detection impedance (15) through a coaxial cable (17); the detected variable frequency power supply (3) is connected with the variable frequency power supply control box (5) through the control optical fiber (4);
The method comprises the following steps:
Firstly, using a standard pulse generator to generate a partial discharge signal with the discharge capacity of 10PC and the frequency of 50Hz, inputting the partial discharge signal into a high-voltage end of a coupling capacitor (14), and calibrating the partial discharge capacity of the test loop through a partial discharge analyzer (18);
Secondly, using a standard pulse generator to generate a partial discharge signal with the discharge capacity of 10PC and the frequency of 50Hz, inputting the partial discharge signal into a low-voltage end of a partial discharge-free isolation transformer (9), measuring a partial discharge capacity signal Q 0 by a partial discharge analyzer (18), and calculating to obtain a partial discharge capacity signal transmission ratio k, wherein k=Q 0/10;
thirdly, adjusting the load value in the variable load device (8) to the maximum value 10Ω, and making the power factor angle be 0 o;
step four, starting a test loop, adjusting the output frequency of the variable-frequency power supply (3) to be 300Hz at maximum, and adjusting the output voltage of the variable-frequency power supply (3) with 5 volts as a step until the output voltage reaches 350 volts at maximum;
step five, gradually reducing the impedance value in the variable load device (10) to 0.30648 Ω, keeping the power factor angle to 0 o, wherein the output current of the variable frequency power supply (3) is 1142 amperes at the maximum value, and recording the local discharge quantity delta Q 1 of the local discharge detector (20);
Step six, reducing and disconnecting the output voltage of the variable frequency power supply (3) through the variable frequency power supply control box (5); calculating the discharge quantity Q 1：Q1=ΔQ1/k=10ΔQ1/Q0 of the variable frequency power supply (3) by using the following formula;
Seventh, through adjusting the load resistance-capacitance ratio in the variable load device (10), the impedance value is 0.30648 Ω, the power factor angle is 45 o, and the steps from the fourth step to the sixth step are repeated, so as to obtain the discharge quantity Q 2 under the working condition;
Eighth, by adjusting the load resistance-capacitance ratio in the variable load device (10) to ensure that the impedance value is 0.30648 Ω and the power factor angle is 90 o, repeating the steps from the fourth step to the sixth step to obtain the discharge quantity Q 3 under the working condition;
ninth, the resistance-capacitance ratio of the load in the variable load device (10) is adjusted to enable the impedance value to be 0.30648 Ω and the power factor angle to be-45 o, and the steps from the fourth step to the sixth step are repeated to obtain the discharge quantity Q 4 under the working condition;
Tenth, the impedance value is 0.30648 Ω, the power factor angle is-90 o by adjusting the load resistance-capacitance ratio in the variable load device (10), and the steps from the fourth step to the sixth step are repeated to obtain the discharge quantity Q 5 under the working condition;
The eleventh step, defining the maximum value of the discharge quantity Q 1, the discharge quantity Q 2, the discharge quantity Q 3, the discharge quantity Q 4 and the discharge quantity Q 5 as a final assessment index quantity Q of the partial discharge quantity of the variable-frequency power supply (3), namely Q=max [ Q 1、Q2、Q3、Q4、Q5 ];
twelfth, if Q is larger than or equal to 21, defining the detected variable frequency power supply (3) as a failure grade; if the Q is less than or equal to 11 and less than or equal to 20, defining the detected variable frequency power supply (3) as a qualified grade; if the Q is less than or equal to 6 and less than or equal to 10, defining the detected variable frequency power supply (3) as a good grade; if Q is less than or equal to 5, the detected variable frequency power supply (3) is defined as an excellent grade.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010520788.4A CN111562475B (en) | 2020-06-10 | Variable frequency power supply partial discharge detection circuit for high-voltage test and evaluation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010520788.4A CN111562475B (en) | 2020-06-10 | Variable frequency power supply partial discharge detection circuit for high-voltage test and evaluation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111562475A CN111562475A (en) | 2020-08-21 |
| CN111562475B true CN111562475B (en) | 2024-07-09 |
Family
ID=
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN212540604U (en) * | 2020-06-10 | 2021-02-12 | 国网山西省电力公司电力科学研究院 | Variable frequency power supply partial discharge amount detection circuit for high-voltage test |
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN212540604U (en) * | 2020-06-10 | 2021-02-12 | 国网山西省电力公司电力科学研究院 | Variable frequency power supply partial discharge amount detection circuit for high-voltage test |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Yao et al. | Transformer winding deformation diagnostic system using online high frequency signal injection by capacitive coupling | |
| CN105974290B (en) | A kind of dry-type air-core reactor turn-to-turn insulation performance detecting system and method | |
| CN103954895B (en) | Oiled paper compound insulation electrical ageing test system | |
| CN107656174B (en) | Method and system for online diagnosis of transformer winding deformation | |
| CN202676858U (en) | Partial discharge test system under impulse voltage | |
| CN107390081A (en) | It is a kind of to be used for the device and method being monitored powered to deformation of transformer winding | |
| CN207181589U (en) | It is a kind of to be used for the device being monitored powered to deformation of transformer winding | |
| CN108548962A (en) | A kind of grounded screen alternating current and direct current and impulse resistance integrated test system and method | |
| CN111289858A (en) | Method for judging partial discharge inside transformer | |
| CN112924905B (en) | Transformer winding insulation evaluation method based on gradient voltage high-frequency oscillation | |
| CN111562475B (en) | Variable frequency power supply partial discharge detection circuit for high-voltage test and evaluation method | |
| CN109212325A (en) | A kind of power cable crosstalk couplings test method | |
| CN110364990B (en) | Method for adjusting measurement precision of stator grounding insulation resistance of injection type generator of nuclear power station | |
| CN212540604U (en) | Variable frequency power supply partial discharge amount detection circuit for high-voltage test | |
| CN110927528A (en) | Transmission line fault simulation test device | |
| CN107271775B (en) | electric power overhead line phase detection method | |
| CN113376548B (en) | Cable state monitoring method and device based on cable aging characteristic extraction | |
| CN215728764U (en) | Integrated calibration system of transformer equipment insulation on-line monitoring device | |
| CN111562475A (en) | Circuit for detecting partial discharge amount of variable frequency power supply for high-voltage test and evaluation method | |
| CN111289938B (en) | Current transformer error calibration equipment | |
| CN210665864U (en) | Single-phase grounding capacitance current testing device of high-voltage power grid | |
| CN113820536A (en) | Zinc oxide arrester live-line detection method based on wireless synchronous current measurement technology | |
| Escurra et al. | IEC 60270 calibration uncertainty in gas-insulated substations | |
| Wan et al. | Fault Detection Technology and Analysis of 10 kV XLPE Power Cable | |
| Alawady et al. | Short-circuit Fault Detection in Power Transformer Using Frequency Response Analysis bipolar signature of Inductive Inter-Winding Measurement |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |