400KV High Frequency DC High Voltage Generator

1LYZGS400KV High Frequency DC High Voltage GeneratorProduct Introduction

LYZGS400KV High Frequency DC High Voltage GeneratorAccording to Chinese industry standardsZBF 24003 – 90According to the requirements of the "General Technical Conditions for Portable DC High Voltage Generators", the research, design, and manufacturing of portable DC high voltage generators is a technological product of the new era. It is suitable for conducting DC high voltage tests on equipment such as zinc oxide lightning arresters, magnetic blow lightning arresters, power cables, generators, transformers, switches, etc. in the power sector, power plants, research institutions, railways, chemical industries, power plants, etc. It is an ideal replacement product for the new century.

LYZGSUsing high-frequency voltage doubling circuit, * appliedPWMHigh frequency pulse width modulation technology, closed-loop adjustment, and the use of voltage feedback greatly improve voltage stability. High power usage performanceIGBTDevices and their driving technology, and based on electromagnetic compatibility theory, special shielding, isolation, and grounding measures are adopted. The DC high-voltage generator achieves high quality, portability, and can withstand rated voltage discharge without damage.

The main components are selected from electronic components with advanced technologies from countries such as the United States, Germany, and Japan, making the instrument more reliable and stable. The double pressure cylinder is developed and produced, and the high-frequency transformer is specially designed by relevant experts, with small size, large capacity, strong overload capacity, and easy on-site operation and testing. Looking ahead, the company will continue to actively explore the market. Taking quality and reputation as our lifeblood, we continuously improve our technological level, develop high-quality products to meet the needs of our customers, strive to explore, and forge the brilliance of the new century.

2、 Product Features

1Smaller in size, lighter in weight, more aesthetically pleasing, more reliable, easy to operate, fully functional, and convenient for outdoor use, it is an ideal and reliable product for the new century.

2Using * technology, process manufacturing, * applicationPWMHigh frequency pulse width modulation technology, pulse train logic array modulation, using high-powerIGBTDevice, utilizing high-frequency technology to increase frequency, with frequencies up to100kHzThus, the output high voltage stability is higher and the ripple coefficient is smaller.

3According to the maintenance free design, the main components are made of imported technology from countries such as the United States, Germany, and Japan, which are durable and not afraid of continuous short circuit discharge to ground.

4High precision and accurate measurement. The voltage and current meters are both digital displays, with a voltage resolution of0.1kVThe current resolution is0.1uAThe voltmeter on the control box directly displays the voltage value applied to the load test sample, without the need for an external voltage divider during use, and the wiring is simple. The instrument has high and low voltage ends for measuring leakage current, and the high voltage end is displayed with a circular shielded digital meter, which is not afraid of discharge shock and has good anti-interference performance, suitable for on-site use.

5The voltage regulation has high stability and smooth voltage regulation across the entire range. The output voltage regulation adopts an imported single multi turn potentiometer, ensuring a smooth boosting process and high adjustment accuracy. It is also designed with coarse and fine adjustment functions. Voltage regulation accuracy is better than0.1%The measurement error of voltage and current is less than1%The pulsation factor is better than0.5%.

6Negative polarity output, zero start, continuously adjustable, with various protection functions such as overvoltage, overcurrent, return to zero, grounding protection, and wire breakage protection. The automatic protection circuit has strong functions, reliable protection, and ensures safe operation. All technical indicators are superior to industry standards and superior to similar products.

7Added high precision75%VDC-1mAThe convenience brought by the function of measuring zinc oxide lightning arresters. A gentle press does not require calculation. There are on the control box of this instrument75%The voltage function key, when conducting lightning arrester tests, when the current rises to1000uAOpen it at the right time0.75The button displays the values on the voltmeter and ammeter75%After completing the data, the boost knob should be immediately returned to the zero position, and the fine adjustment voltage knob should be returned to the zero position. The green button should be immediately pressed to cut off the high voltage and turn off the power switch. Conduct other experiments.

8The convenient overvoltage setting function adopts a digital dial switch, which can intuitively display the set voltage value, making your operation more flexible and intuitive

The unit of display value iskV.

9The double pressure cylinder can be divided into sections for on-site use, which is flexible and convenient. It can be used for multiple purposes and is economical.

10There are three concealed support feet at the bottom, which increase the stability of the pressure doubling cylinder.

3、 Electrical working principle diagram

picture1 Working principle diagram

4Product specifications and main technical performance

5、 Instructions for use

1Instructions for using panel components

⑴ High frequency output and rapid connection of voltage and current measurement cables to multi-core sockets:Used for connecting the chassis with the voltage doubling part. When connecting, simply align the white dot on the cable plug with the white dot on the socket and rotate it clockwise to the correct position. To disassemble, simply turn the cable plug counterclockwise. attention:When installing or removing plugs,Please grip the metal ring of the plug tightly and rotate it. It is strictly prohibited to hold and pull the cable for rotation,To avoid disconnection between the plug and the cable.

⑵ Digital Display Voltmeter:LCDLCD digital display DC high voltage output voltage,unitkV,The small resolution is ±0.1kV.

⑶ Digital Display Ammeter: LCDLCD digital display DC high voltage output current,unituA,The small resolution is ±0.1uA.

⑷ Power fuse holder:The fuse is10A.

⑸ Power input socket:Single-phase AC220V±10%,50HzConnect the randomly configured power cord to the power input socket(The socket comes with a built-in fuse

pipe10AOr a separate insurance seat).

⑹ Grounding terminal post:This grounding terminal is connected to the grounding terminal of the voltage doubler cylinder and the grounding of the test sample at one point,Connect to the grounding grid again.

⑺ Overvoltage setting dial switch:Used to set overvoltage protection values. The overvoltage setting range is0.05-1.2Within double the rated voltage,The value displayed by the dial switch is in units ofkV.

⑻ Single and double section selection switch(Double section double pressure cylinder)Voltage full shift(section)switch:When the switch is turned to1time,The double pressure cylinder is a single section,The voltmeter displays the voltage of a single voltage doubler cylinder;When the switch is turned to2time,The pressure doubling cylinder is a double section,The voltmeter displays the voltage of the double section voltage doubler.

When using a double pressure cylinder, please align the white mark on the lower flange of the upper section with the white mark on the upper flange of the lower section, and then rotate it clockwise until it touches the foot(about30Angle left and right),The electrical connections between the upper and lower sections are in place,On the contrary, it means to remove it.

When used in a single section,Please don't forget to install the top cover on the other end of the configuration,Install it onto the top of the next section using the above method.

⑼75%VDC-1mAUse the yellow illuminated button:Effective when the red light is on. When the yellow button is pressed, the yellow light will turn on,Reduce the output high voltage to its original level0.75times,And maintain this state,This function is specifically designed for rapid measurement of zinc oxide lightning arresters0.75VDC-1mA,Press the green button to turn off both the red and yellow lights,High voltage cut-off and exit0.75Double the state.

⑽ Green illuminated button:The green light indicates that the power supply has been connected and the high voltage has been disconnected. When the red light is on,Press the green button,Red light off, green light on,Cut off the high-voltage circuit.

⑾ Red illuminated button, high voltage connection button, high voltage indicator light:When the green light is on,After pressing the red button,Red light on, green light off,Indicates that the high-voltage circuit is connected. At this time, the voltage can be increased. This button is only effective when the voltage regulating potentiometer is reset to zero. If the red button is pressed, the red light will turn on,The green light is still on,But when the button is released, the red light will turn off and the green light will turn on,Indicates that the internal protection circuit is working,At this point, it is necessary to shut down and check if the overvoltage setting dial switch is less than the full range5%And whether there are any other faults,Check for accuracy before turning on the device.

⑿ Rough adjustment voltage regulator potentiometer:This potentiometer is a coarse adjustment multi turn potentiometer,Clockwise rotation is for boosting,On the contrary, it is to lower the pressure. This potentiometer has the function of controlling electronic zero position protection. Therefore, it is necessary to return to zero before boosting. Voltage regulation accuracy0.1%kV,After the experiment is completed,The potentiometer should return to zero position.

⒀ Fine tuning voltage regulator potentiometer:To adjust accuracy,This potentiometer fine tunes the multi turn potentiometer,Clockwise rotation is for boosting,The boost is very slow,On the contrary, it is to lower the pressure. Fine tuning is generally used to adjust the voltage accuracy and conduct tests on zinc oxide lightning arresters,It is used to adjust the accurate current. After the experiment is completed,The potentiometer should return to zero position.

⒁ power switch:Press this switch upwards,Power on,Green light on;Conversely, it is turned off. Avoid using this switch to directly turn off high voltage,When shutting down,Firstly, return the voltage coarse adjustment and fine adjustment potentiometers to zero position,Then turn off the power switch.

2Instructions for using the pressure doubling cylinder

picture4 Single section pressure doubling cylinder picture5 Double section double pressure cylinder

1.High voltage lead terminal 2.Equal pressure cover

3.Double pressure cylinder body 4.Previous section: Double pressure cylinder

5.Upper and lower section connecting flanges 6.Next section pressure doubling cylinder

7.grounding terminal 8.Connect the cable socket to the control box

9.△-YTelescopic pin

6、 Operation steps

1Preparation before use

⑴ The integrity of the DC generator should be checked before use,There should be no open or short circuits in the connecting cables,The equipment is not damaged or broken.

⑵ Place the chassis and pressure doubler in a suitable and safe location,Connect the power line, cable line, and grounding wire separately. The protective grounding wire, the working grounding wire, and the grounding wire of the discharge rod should be separately connected to the grounding wire of the test sample(Just a little grounding)It is strictly prohibited to use grounding wires in series with each other,To prevent the ground potential from rising and forming a counterattack during breakdown,Damaged instrument.(See figure6)

picture6 Schematic diagram of test sample wiring and method of connecting grounding wire

⑶ Check if the power switch is in the off position,And check that the voltage regulator potentiometer should be in the zero position,Set the overvoltage protection setting dial switch in the appropriate position,generally1.10～1.20Double the test voltage value.

2Verification of overvoltage protection setting value for no-load boosting

⑴ Please confirm that the power supply is single-phase AC220V,50Hz.Turn on the power switch,At this moment, the green light is on,Indicates that the power is connected.

⑵ Press the red button,Then the red light will turn on,Indicates high voltage connection.

⑶ Gently adjust the potentiometer in a clockwise direction for coarse and fine adjustment,The output terminal starts boosting from zero. After reaching the required voltage,Record the reading of the ammeter according to the prescribed time,And check if there are any abnormal phenomena or sounds in the control box and output cables. If necessary, calibrate the DC high voltage indicator on the control box with an external high voltage divider.

⑷ lower blood pressure,After resetting the voltage regulator potentiometer to zero,Then press the green button,Cut off the high voltage and turn off the power switch.

3Conduct leakage and DC withstand voltage tests on the test sample

⑴ Before conducting the load test,Install the high-voltage shielded microampere meter onto the high-voltage output terminal of the high-voltage multiplier cylinder,And connect the matching shielding wires to the microampere meter and the test sample respectively(Please refer to the user manual for the high-voltage shielded microampere meter for details).

⑵ Check if the instrument, discharge rod, voltage doubler, test sample connection wire, and grounding wire are correct,Is the grounding wire connection reliable,Check if the high-voltage safety distance meets the requirements,High voltage testing of the test sample can only begin.

⑶ After checking and confirming that there are no abnormal conditions in the instruments, etc,Connect single-phase AC220Vpower switch,At this moment, the green light is on,Indicates that the power is connected. We can start conducting DC leakage and DC withstand voltage tests on the test sample.

⑷ Press the red button,Then the red light will turn on,Indicates high voltage connection,Wait to increase the high voltage.

⑸ Gently adjust the potentiometer in a clockwise direction for coarse and fine adjustment,The output terminal starts boosting from zero. Boosting speed per second3-5kVIt is advisable to increase the test voltage. For large capacitor test samples, the voltage should be increased slowly,Otherwise, it may cause voltage overshoot,It is also necessary to monitor that the charging current of the ammeter does not exceed the high charging current of the DC generator. When the required voltage or current is reached,Record the readings of the ammeter and voltmeter according to the prescribed time.

⑹ After the experiment is completed,lower blood pressure,After roughly and finely adjusting the voltage potentiometer back to zero,Then press the green button,Cut off the high voltage and turn off the power switch.

⑺ After the experiment is completed,Apply a discharge rod to discharge the test sample multiple times,Only after discharge can one approach the test sample and perform wire removal work(Please refer to the discharge rod instruction manual for details on discharge).

For small capacitor test samples such as zinc oxide lightning arresters, magnetic blow surge arresters, etc., first roughly adjust them to the required voltage(current)of90%,Then slowly increase the voltage to the desired level using a fine tuned potentiometer(current)value,Then read the voltage from the digital display(current)Numerical value. If zinc oxide lightning arrester needs to be tested75%VDC-1mAWhen measuring,Should first increase the current to1mAWhen the voltage value stops(At this point, voltage and current values can be recorded),Then press the yellow button,The voltage drops to its original level75%,And maintain this state. At this time, the microampere meter value and voltage value can be read. After the measurement is completed,Adjust the potentiometer counterclockwise to return to zero position,Press the green button,Press the red button when you need to increase the voltage again.

When testing large capacitors,The voltage should be increased more slowly,And it is necessary to monitor that the charging current of the ammeter does not exceed the large charging current of the generator,Be sure to slow down the boost speed,Avoid excessive charging current. After the experiment is completed,Return the voltage regulator potentiometer counterclockwise to the zero position,Then press the green button,Cut off high voltage. At this point, pay attention to the voltage drop on the voltmeter15kV左右,Multiple discharges can be carried out using a discharge rod,Ensure safety.

4Several measurement methods

⑴ During general measurement,After connecting the wires,First, suspend the wire connecting the test sample,After reaching the test voltage,Read the corona and stray current during the air testI′,Then connect the test sample and raise it to the test voltage,Read the total currentI1.

Leakage current of the test sample:I0=I1- I′

⑵ When precise measurement of the leakage current of the test sample is required,High voltage shielded microampere meters should be connected in series in the high-voltage circuit,See figure7a.

picture7aHigh voltage shielded microampere connected to the test sampleCxHigh voltage side wiring diagram. High voltage shielded microampere meters must have metal shielding,

Shielded wire should be used to connect with the test sample,The shielding lead of the high-voltage lead should be tightly connected to the shielding of the instrument end. If we want to eliminate the influence of surface leakage current of the test sample,It can be tightly wound with bare metal flexible wire at the high potential end of the test sample and connected to the shielding of the high voltage lead after several turns(See figure7b).

picture7bWiring diagram for eliminating surface leakage current of the test sample

⑶ When the grounding terminals of samples such as zinc oxide lightning arresters and magnetic blow surge arresters can be separated,It can also be used at the bottom of the test sample

ministry(Ground potential side)The method of measuring by connecting an ammeter in series,But shielded wires must also be used(See figure8a)When eliminating the influence of surface leakage current of the test sample,Soft bare copper wire can be wound several times around the ground potential end of the test sample and connected to the shield(See figure8b).

⑷ Experiment completed,lower blood pressure,After resetting the voltage regulator potentiometer to zero,Then press the green button,Cut off the high voltage and turn off the power switch.

⑸ For small capacitor samples such as zinc oxide lightning arresters,Generally, discharge is carried out through a pressure measuring resistor,Time flies. And for large capacitance test samples such as cables and motors,Usually, it is necessary to wait for the sample voltage to self discharge to the test voltage20%below,Then discharge through the discharge rod. After the test sample is fully discharged, hang the grounding wire,Only then can the removal and replacement of high-voltage leads be allowed.

5Operation after protective action

During use, it was found that the red light went out,Green light on,DC high voltage drop,It is about protective actions. At this point, the following steps should be followed:

⑴ Return the voltage regulator potentiometer to zero position.

⑵ Turn off the power switch,The panel indicator lights are not on.

⑶ one minute later,After fully discharging the low-voltage capacitor in standby mode,Only then is it allowed to turn on the power switch again. Repeat the no-load test,After investigating the situation,Further voltage boosting test can be conducted.

7、 Fault inspection and handling

8、 Instructions for using current limiting resistors

1Current limiting resistor function:When the test sample breaks down or flashes,Plays a role in limiting the current,So as not to damage the testing equipment.

2Usage method:Just connect one end of the current limiting resistorM10Screw the nut onto the top of the double pressure cylinder of the DC high-voltage generator,Just tighten the bolts on the high-voltage output line. If you want to connect a high-voltage microampere meter in series(Choose another optionSWB-VType Table),Just place the microampere meter at the bottomM10Simply screw the nut onto the other end of the current limiting resistor.

3If usedLYZGSWhen using a series of DC high-voltage generators,When the test samples are zinc oxide lightning arresters, valve type lightning arresters, and high-voltage switches and other electrical equipment,You don't need a current limiting resistor. All samples with small current and small capacitance,You don't need a current limiting resistor.

4Large capacitance test samples such as power cables, transformers, motors, etc,A current limiting resistor should be connected in series in the high-voltage circuit for testing,Protect the experimental equipment.

9、 Precautions

1Please make sure to repeatedly check whether the connecting wires and grounding wires are correct,All parts should be well grounded,It is strictly prohibited to connect grounding wires in series. Pay attention to safe distance,Ensure personal safety.

2After each experiment,The boost potentiometer should be returned to zero position(Both coarse and fine adjustments return to zero position),Press the green button,Cut off the high voltage and turn off the power switch,Then discharge.

3Please do not open the instrument without permission, as this will affect the warranty of the product. The manufacturer is not responsible for disassembling on their own.

4During the transportation of instruments, rainwater erosion should be avoided,Take strict precautions against collisions and falls.

10、 Product completeness

1Control the chassis 1Taiwan; 2High pressure multiplier cylinder 1section(or2section)；

3Power cord 1Root; 4High frequency output multi-core cable 1Root;

5Backup fuse10A 3Only; 6User Manual 1Share;

7Product inspection certificate, warranty card 1Share; 8Product Factory Acceptance Test Report 1Share;

9TheLYZGSTelescopic discharge rod 1Root; 10TheLYZGSTelescopic discharge rod grounding wire 1Root;

11Current limiting resistor 1Support; 12TheSWB-VHigh voltage shielded microampere meter 1Only;

13Micro ampere meter test line, clamp 1Set;

11、 Optional parts

1TheSWB-VHigh voltage shielded microampere meter;

2Various specifications of high-voltage output cables and lead clamps;

3Various specifications of pressure covers(For use by the testing bureau)；

4Current limiting resistor;

5Various specifications of aluminum alloy boxes.

1、 Product Overview

YDQCThe series of lightweight AC/DC high-voltage test transformers are among similar productsYDJ（G）On the basis of the high-voltage test transformer, according to the national standard for test transformersModel No.: ZBK41006—89Requirement: A new type of product produced after improvement, this series of products has the characteristics of small size, light weight, compact structure, complete functions, and easy use. It is a practical instrument used in power, industrial and mining, scientific research and other departments to conduct power frequency withstand voltage tests and DC leakage tests on various high-voltage electrical equipment, electrical components, and insulation materials. It is the * instrument in high-voltage testing.

2、 Product Structure

YDQCThe series of lightweight high-voltage test transformers have a single frame iron core. The coil adopts a multi-layer tower structure with the same core cylinder. The primary low-voltage winding is wound on the iron core, and the secondary high-voltage winding is wound on the outside of the low-voltage winding. This coaxial arrangement reduces the coupling loss between the windings. The high-voltage silicon stack is encapsulated in a sleeve using a special process, and the outer shell of the product is made into an octagonal structure that fits well with the core, resulting in an overall beautiful and elegant appearance. The internal and external structures are shown in the diagram1.

Product model meaning

Y D Q C（ ）—□/□

picture1：YDQCSchematic diagram of experimental transformer structure
1-Equal pressure ball;2-Silicon stack short-circuit rod;3-High voltage casing;4-Oil valve;5-Shell;6、7-Adjust voltage inputaThexTerminal;8、9-instrument measurementETheFTerminal;10-High pressure tailXTerminal;11-Grounding terminal of transformer casing;12-high voltage outputATerminal;13-High voltage rectifier silicon stack;14-Internal pressure equalization ring;15-Transformer iron core;16-Primary low-voltage winding;17-Measuring instrument winding;18-Secondary high voltage winding;19-Transformer oil.

3、 Working principle

YDQCThe series of lightweight high-voltage test transformers are single-phase transformers with connection group numbersIIThe working process of a single high-voltage test transformer is conducted using alternating current220V（10KVAThe above is380V）The voltage is connected to the power control box (platform) and is regulated by the self coupling voltage regulator inside the power control box (platform)（50KVAThe above regulator is attached for external adjustment0~200V（10KVAabove0~400V）The voltage is applied to the primary winding of the test transformer, and according to the principle of electromagnetic induction, the high voltage required for the test can be obtained in the high-voltage winding of the test transformer. The working principle diagram is shown in the figure2As shown.

1Single unitYDQCSchematic diagram of working principle of high-voltage test transformer

picture2 : Single unitYDQCSchematic diagram of working principle of high-voltage test transformer
In the experimental transformer:aThexFor low voltage input terminal;ATheXFor the high-voltage output terminal;ETheFFor the instrument measurement end.
2The working principle of a single AC/DC dual-purpose high-voltage test transformer is shown in the figure3As shown in the figure, a high-voltage silicon stack is installed inside the high-voltage bushing, which is connected in series in the high-voltage circuit for high-voltage rectification to obtain high DC voltage. When a short-circuit rod is used to short-circuit the high-voltage silicon stack, AC high voltage can be obtained, and its state is AC output; On the contrary, when the short-circuit rod is pulled out, its state is DC output.
3The principle of obtaining higher voltage through series excitation of three high-voltage test transformers is shown in the figure4The series excited high-voltage test transformer has great flexibility because the entire test device consists of multiple single series excited test transformers. Each single test transformer has the characteristics of small size, light weight, and easy transportation. It can be connected in series to form a single test transformer with output voltage several times higher, or used separately. The entire experimental setup requires minimal investment and is cost-effective. picture3As shown: In the series excitation use of three series excitation test transformers, a single test transformerB1TheB2TheB3The output voltage isUThe secondary test transformers both have an excitation winding inside, which isA1TheC1andA2TheC2When the control voltage is applied to the * level test transformerB1The primary windinga1Thex1Up, excitation windingA1TheC1Provide a test transformerB2Primary winding power supply, secondary test transformerB2The excitation windingA2TheC2Provide the test transformerB3The primary winding is powered. Due to the * level test transformerB1High voltage tail and shell grounding, second and third stage test transformersB2andB3Isolation of transformers with insulated supports on the ground is used for testingB1TheB2TheB3The output voltages to ground are1UThe2UThe3U.

picture3Schematic diagram of series excitation working principle of three high-voltage test transformers
B1TheB2TheB3-Series excited high-voltage transformer;1UThe2UThe3U-Ground voltage at all levels;
PV-High voltage indication table（KV）；ZJ1TheZJ2-Insulated bracket.

4、 Usage and precautions

1TheYDQCThe wiring method for conducting power frequency withstand voltage test on high-voltage test transformers is shown in the figure5Before conducting the power frequency withstand voltage test, select the current limiting resistor based on the rated capacity of the test transformer,(Water resistance)The resistance value of the discharge ball gap should be adjusted according to the required high voltage value of the test sample. In order to improve the measurement accuracy of the applied voltage to the test sample, it should be connected to the high voltage sideFRCResistive capacitive voltage divider is used to measure voltage.

picture4Schematic diagram of wiring principle for power frequency withstand voltage test
R1TheR2-Current limiting resistor;Qx-Discharge ball gap;Zx-Subject matter;
FRC-Resistive capacitive voltage divider;V-High pressure gauge for voltage divider.
According to the diagram4Combined with the diagram2The power frequency withstand voltage test conducted involves connecting the working circuit and testing the high voltage winding of the transformerXEnd (high pressure tail), instrument measurement windingFThe casing of the terminal and test transformer, as well as the casing of the power control box (platform), must be reliably grounded.
When conducting a power frequency withstand voltage test using three test transformers in series, the primary winding of the second and third stage test transformersXEnd, instrument measurement windingFEnd and high voltage windingXBoth ends (high pressure tail) are connected to the outer shell of the current stage test transformer, and the main bodies of the second and third stage test transformers must be placed on insulated supports. Except for level *, the main body of the second and third level test transformers should not be grounded. The wiring method is shown in the figure3As shown.
Before connecting to the power supply, the voltage regulator of the power control box (platform) must be set to zero position. After connecting the power supply, the green indicator light will turn on. Press the start button once, and the red indicator light will turn on, indicating that the test transformer has been connected to the control power supply and started to increase the voltage.
Start from zero position and rotate the regulator handwheel clockwise at a constant speed to increase the pressure. (Boosting methods include: fast boosting method, i.e20SStep by step boosting method, slow boosting method, i.e60SStep by step boosting method, extremely slow boosting method available) The voltage is raised from zero to the rated test voltage you require at the selected boosting speed75%Afterwards, at a rate of per second2%Raise the speed of the rated test voltage to the desired test voltage, and pay close attention to the indication of the measuring instrument and the condition of the test object. After the time for applying voltage to the test object is up. The regulator should be returned at a constant speed within a few seconds, and the high pressure should be reduced to1/3Below the test voltage, press the stop button once to stop the high and low voltage output, and then cut off the power cord. The test is complete.

Precautions for the operation process of power frequency withstand voltage test

1Test personnel should divide their responsibilities properly,Set a safe distance for the test site,Carefully check the grounding condition of the test sample and the test transformer,And there is a dedicated person to monitor safety and observe the status of the test sample.
2The main parts of the test sample should be cleaned and kept dry to avoid damaging the sample and causing errors in the test values.
3For the testing of large equipment, it is generally necessary to conduct a no-load test of the test transformer, that is, to increase the voltage to the test voltage without connecting the test sample, in order to calibrate the accuracy of the instrument indication and adjust the ball spacing of the discharge ball gap.
4When conducting a voltage withstand test, the boosting speed should not be too fast, and sudden boosting should be prevented. For example, if the regulator is not at zero position, it should be suddenly closed, and the power should not be suddenly cut off. Generally, it should be closed when the regulator drops to zero position.
5During the boost or withstand voltage test, if any of the following abnormal situations are found,1 The pointer of the voltage and current meter swings greatly,2 The test sample made abnormal noises,3 If insulation is found to be burnt or smoking, the voltage should be immediately reduced, the power should be cut off, the test should be stopped, and the cause should be identified.
6When using this product for high-voltage testing, in addition to being familiar with this manual, it is also necessary to strictly follow relevant national standards and operating procedures.

2TheYDQThe wiring method for conducting DC withstand voltage and leakage tests on AC/DC dual-purpose high-voltage test transformers is shown in the figure5As it is a dual-purpose high-voltage test transformer for both AC and DC, the short-circuit rod of the high-voltage silicon stack should be extracted from the bushing to put the test transformer in a DC output state. Before conducting a DC leakage test, it is advisable to choose the resistance value of the current limiting resistor (water resistor) based on the large rectification of the high-voltage silicon stack, and then select the capacitance value of the high-voltage filtering capacitor according to the requirements of the test object for the DC high-voltage waveform. In order to improve the measurement accuracy of applying voltage to the test sample, it should be connected to the high voltage sideFRCResistive capacitive voltage divider is used to measure voltage.

picture 5Schematic diagram of wiring principle for DC leakage test
R-Current limiting resistor;C-High voltage filtering capacitor;Zx-Subject matter;G-Silicon stack short-circuit rod;
FRC-Resistive capacitive voltage divider;V-High pressure gauge for voltage divider;uA-Microampere meter;D-High voltage rectifier silicon stack.
According to the diagram5Combined with the diagram3Connect the working circuit of the DC leakage test conducted. The high-voltage winding of the test transformerXEnd (high pressure tail), instrument measurement windingFThe casing of the terminal and test transformer, as well as the casing of the power control box (platform), must be reliably grounded.

YDQCSchematic diagram of AC test wiring for experimental transformation

YDQCSchematic diagram of AC leakage test wiring for experimental transformation
Before connecting to the power supply, the voltage regulator of the power control box (platform) must be set to zero position. After connecting the power, the green indicator light will turn on. Press

Press the start button and the red indicator light will turn on, indicating that the test transformer has been connected to the control power supply and is starting to increase the voltage.
Start from zero position and rotate the regulator handwheel clockwise at a constant speed to increase the pressure. (Boosting methods include: fast boosting method)20SStep by step boosting method; Slow boost method, i.e60SStep by step boosting method; The voltage is increased from zero to the reference voltage at the rated test voltage or rated DC current at the selected boosting speed. During the experiment, close attention should be paid to the indication of the DC high voltage meter, leakage current meter, and the condition of the test object. After the experiment is completed, the high voltage should be uniformly lowered to zero, and the stop button should be pressed once to stop the high and low voltage output, and then the power should be cut off. At this time, a DC high-voltage discharge rod should be used to fully discharge the test sample and the testing device itself.

Precautions for DC leakage test operation process

（1）Test personnel should divide responsibilities, set a safe distance at the test site, carefully inspect the grounding of the test sample and test transformer, and assign a dedicated person to monitor safety and observe the status of the test sample.
（2）Before conducting the experiment on the test sample, all external connections should be removed and fully discharged. The main parts should be cleaned and kept dry to avoid damaging the test sample and causing errors in the test values.
（3）For large capacity test samples (capacitors, ultra long cables, etc.), the voltage should be slowly increased to prevent the microampere meter from being burned out due to excessive charging current of the test sample. If necessary, the microampere meter should be read for stable readings at different voltages by gradually increasing the voltage.
（4）During the experiment, the test object, microampere meter, and testing device should be closely monitored. In case of flickering, breakdown, or other phenomena, the voltage should be immediately reduced, the power should be cut off, and the cause should be identified.

5、 Supporting product selection

The following products are for selection only and require additional pricing at the time of purchase.
1.KZXSeries power control box capacity1KVA-5KVA:Input voltage:220V
2.KZTSeries power control console capacity10KVA~300KVAInput voltage:220Vor380V
3.Digital microampere meter:SWB-II
4.High voltage filtering capacitor:0.01MFThe40 ~ 100KV
5.High voltage DC discharge rod:FBR— 70、140The210KV
6.Discharge ball gap:Q—50、100、150、200、250、500
7.Standard oil test cup:400ml
8.Folding handcart: 150、300type
9.Insulation bracket: 50、100、200、300The400KV
10.Resistive capacitive voltage divider:FRC—50、100、150The200KV
11.High voltage silicon stack:2DL—150、300The450KV
12.water electricity Resistance: 50、100

6、 Selection of main experimental equipment

1Test Transformer
The rated voltage on the high voltage side should not be less than the high test voltage of the test object, and the rated current should not be less than the large capacitor current of the test object. The calculation formula for the capacitance current of the test sample and the required capacity of the test transformer is:

Capacitance of the test sampleCxIt can be measured by an AC bridge. The capacitance of commonly used test samples is shown in the table1selection.

The capacitance of several commonly used test samples（pF） table1

2Pressure regulating equipment
（1）Self coupling voltage regulator. It has a wide voltage regulation range, low power loss, and minimal waveform distortion. The choice of this voltage regulation method is. The capacity of the self coupling voltage regulator is determined by0.75 ~ 1The capacity selection of the double test transformer is suitable for a capacity of100KVAThe voltage regulation of the following test transformer.
（2）Inductive voltage regulator. Its voltage regulation range is large, the waveform distortion is small, but the structure is complex and the price is relatively expensive. When the capacity of the test transformer is large (such as100KVA(Above) Use.
3Current limiting resistor
The function of a current limiting resistor is to limit the breaking current when the test object breaks down, thereby protecting the test transformer and preventing the expansion of the fault. Its value is based on the high test voltage, according to0.5 ~ 1Ω/ V(Effective value) selection, the current limiting resistor can be a water resistor. Be careful not to fill the glass tube with water and leave room to prevent it from bursting.
4Discharge ball gap
There are two ways to arrange the discharge ball gap: vertical and horizontal, with a spacing between the ball gapsSAnd the diameter of the ballDThe relationship should be protected0.05D≤S≤0.5DWithin the range, the resistance value of the water resistor on the ball gap is generally determined by0.1 ~ 1Ω/Vselect,The purpose of setting the discharge ball gap is to provide protection for important test subjects,Overvoltage caused by misoperation or sample breakdown can be limited within the allowable range.

7、 Technical instructions for test transformers

1Environmental conditions for use
The ambient temperature is not higher than+40℃, not less than -20℃； The relative humidity of the air is not greater than90%The altitude does not exceed2000Rice;
2Working voltage
The input voltage of the power control box (unit) is the power frequency220Vor380VThe relative error shall not exceed ±10%The specific voltage to be used will be selected based on the specifications of the test transformer specified by the user
8、 Accompanying documents

Product manual 1copy
Product factory test report 1copy
Product Qualification Certificate 1copy
Packing List 1copy