High voltage generatorDC high-voltage generator, Yeshigh-voltage power supplyThe traditional name ofHigh voltage electricityAt present, there is no strict difference between high-voltage power supply and high-voltage generator.English: high voltage power supply is called HVPS for short.High frequency DC high voltage generator adopts high frequency voltage doubler circuit, the latest PWM high frequency pulse width modulation technology, closed loop adjustment, and large voltage feedback to greatly improve the voltage stability.High power IGBT device with excellent performance and its drivertechnologyAccording to the electromagnetic compatibility theory, special shielding, isolation and grounding measures are adopted.The DC high-voltage generator is of high quality and portable, and can withstand rated voltage discharge without damage.
VLF 0.1HZ ultra-low frequency high voltage generator combines modern digital frequency conversion advanced technology and adopts microcomputer control.Boost, drop, measurement and protection are fully automated.And manual intervention can be carried out in the process of automatic pressure rise.Because it is all electronic.It can be widely used in AC withstand voltage test of cables, rotating motors and power capacitors.
DC high-voltage generatorThe intermediate frequency rectification and filtering technology is adopted to solve the problems of large ripple coefficient and unstable waveform of power frequency DC high-voltage generator.New scientific and technological products newly researched, designed and manufactured by DC high-voltage generator are applicable to zinc oxide in power sector, power sector of factories and mining enterprises, scientific research institutions, railways, chemicals, power plants, etcLightning arresterMagnetic blow arresters, power cables, generators, transformers, switches and other equipment for DC high-voltage tests are the most ideal replacement products in the new century.The intelligent DC high-voltage generator applies a new generation of PWM high-frequency pulse width modulation technology, adopts high-end intermediate frequency voltage doubling circuit, high-performance closed-loop adjustment, high voltage and large feedback, and greatly improves the voltage stability.According to the national standard General Technical Conditions for Portable DC High Voltage Generators (ZGF24003-90), on the basis of the original DC high voltage generator, it conforms to the principles of the Japanese electric electromagnetic compatibility theory, adopts the principles and methods of special shielding, isolation, grounding and other measures of the national standard method, uses high-power IGBT devices with better performance and their driving technology, modern electronic high-tech chips,Intelligent operation makes the intelligent DC high-voltage generator more intelligent and portable, and further expands the range of withstand voltage without damage.[1]
Generator characteristics
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The DC high-voltage generator is the latest research, design and manufacturing product of the new era - portable DC high-voltage generator according to the requirements of the Chinese industry standard ZBF 24003-90 General Technical Conditions for Portable DC High Voltage Generators. It is suitable for the power sector, scientific research units, railways, chemicals, power plants, power departments of large enterprisesDC high voltage test and leakage current test shall be conducted for magnetic blow arrester, power cable, generator, transformer, switch and other equipment.
It adopts pulse width modulation (PWM) technology, IGBT, and advanced electronic circuits and components, with output free from grid fluctuation interference, zero position, overcurrent, breakdown, overvoltage and other protective measures. Whether the overcurrent, breakdown, overvoltage protection circuit can act quickly, effectively guaranteeing the safety of equipment and personnel.Its output adopts LCD display, and its volume and weight are much lighter than the original KGF type, which is very suitable for field use.The newly designed "0.75U" LCD can directly display and latch 0.75U1mA field test without manual calculation.
High precision and accurate measurement.The voltage and ampere meters are digital displays, with a voltage resolution of 0.1kV and a current resolution of 0.1uA. The voltmeter on the control box directly displays the voltage value applied to the load test object. No external voltage divider is required for use, and the wiring is simple.The instrument has high and low voltage terminals to measure the leakage current. The high voltage terminal is displayed by a circular shielded digital meter, which is not afraid of discharge shock, and has good anti-interference performance, suitable for field use.
The voltage regulation has high stability, full range smooth voltage regulation, and the output voltage regulation adopts imported single multi turn potentiometer, which has stable boosting process, high regulation accuracy, and is designed with coarse and fine adjustment functions.The voltage regulation accuracy is better than 0.1%, the voltage and current measurement error is less than 1.0%, and the ripple factor is better than 0.5%.[1]
technical conditions
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Power supply: AC220V ± 10%, 50Hz ± 1%;
Output voltage indication accuracy:<Level 1;
Output current indication accuracy:<Level 1;
Ripple coefficient: ≤ 0.5%;
0.75 times output voltage indication accuracy:<Level 1, with latch.[1]
Service conditions
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Relative humidity: no more than 85% at 25 ℃, no condensation;
Working mode: intermittent use for 30 minutes;
Ambient temperature: - 10~40 ℃;
Altitude: below 1500m.[1]
Protection function
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Internal over-voltage protection and internal over-current protection;
External overvoltage protection (protection voltage can be set), external overcurrent protection or breakdown protection;
Internal power protection;
Non zero starting protection;
Timed audible alarm.[1]
Test object test
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Connect the test object between the high-voltage output terminal and the ground terminal.
Turn on the power switch, gently press the "Start" button, the "Power" indicator light (red) lights up, and slowly adjust the voltage coarse adjustment knob and the voltage fine adjustment knob for testing.During the test, the voltage display meter indicates the test voltage value, in kV;75% of the test voltage indicated by the 0.75 times voltage display meter, in kV;The current display meter indicates the test current value in mA.
Press the 0.75 times voltage display latch button during the test of the test object, the display value of the 0.75 times voltage display meter will be locked, and it is inconvenient to maintain the display value, so that it can be used as the reference voltage conveniently during the zinc oxide arrester test.Press the timing on button at any time to start the time relay. When the timing reaches the preset time, the buzzer will give an alarm.During the test, if the load current exceeds 0-10% of the rated output current of the instrument, the "over-current" indicator will be on to protect the test object and instrument from damage.
After the test, adjust the voltage coarse adjustment knob and the voltage fine adjustment knob counterclockwise. After turning to the zero position, the voltage display meter slowly returns to the zero position, and the "zero position" indicator light is on.When the three display meters display zero values, gently press the stop button, the red indicator light will go out, and then turn off the power switch.When the capacitance of the tested object is large, and the output voltage display meter fails to return to zero after the coarse and fine voltage adjustments are both set to zero, press the stop button first, and then turn off the machine.Then use the discharge rod to discharge the tested object, and then remove the wiring of the tested object.[2]
matters needing attention
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1. During the cable withstand voltage test, the voltage rise process should be constant and slow, and the voltage drop process should also be constant and slow. At the same time, a protective water resistance should be added at the high-voltage output end.Otherwise, the counter voltage may damage the instrument.
2. During the instrument test, the grounding must be good, and the grounding grid or pile shall be selected. The test cannot be conducted without grounding.
3. The workers who use the DC high-voltage generator must have a "high-voltage test certificate".
4. When using this instrument, the user must comply with Article 168 of the Electric Power Safety Regulations and install two obvious disconnection points before the working power enters the tester.When replacing the test object and wiring, the two power supply disconnection points shall be obviously disconnected first.
5. Before the test, please check whether all test wiring, control box, voltage doubling cylinder and the grounding wire of the test object are well connected.The grounding wire of the test circuit shall be grounded at one point as shown in this manual.
6. For the discharge of large capacitance test objects, ZS special discharge resistance bar shall be used to discharge the test objects.When discharging, the discharge rod cannot contact the test object immediately. First, the discharge rod should be gradually close to the test object, and free discharge should be started at a certain distance from the air gap. There is a hissing sound. When there is no sound, the discharge rod can be used to discharge, and finally the ground wire can be directly connected to discharge.
7. When the DC high voltage is 200kV or above, although the tester wears insulating shoes and is located outside the safe distance, due to the influence of the distribution of the electric field in the high-voltage DC ion space, several nearby standing human bodies will have different DC potentials.Testers should not shake hands with each other or touch the grounding body with their hands, otherwise there will be slight electric shock. This phenomenon is more obvious in dry areas and winter, but generally it will not cause harm to human body due to low energy.
8. The power supply of ZS series portable ultra light DC high-voltage generator control box is AC 220V ± 10%, 50Hz.If the power supply passes through 1/1 isolation transformer or spontaneous power supply is used on site, the power supply must be manually connected to the ground at one point.[2]
Operation and steps
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Preparation before operation
Connect the output cable socket of the control box with the cable socket of the voltage doubling device with a special cable. Check the integrity of the instrument before use. The connecting cable should not be short circuited or open circuited;The pressure doubling cylinder shall be free of condensation;Connect the grounding of the control box and the grounding terminal of the voltage doubling device with 2.5mm2 or more copper wires and reliably ground them.
Operation process
(1) Connect the test object between the high-voltage output terminal and the ground terminal.
(2) Plug in the power cord, turn on the power switch, and the "HV Off" indicator (green) will be on, and the "HV On" indicator (red) will be off;The voltage display meter, current display meter and 0.75 times of voltage display meter display zero value.
(3) Turn the voltage and current setting knob clockwise to the end, and the voltage regulating knob counterclockwise to the zero position.(Note: the voltage regulating knob is not at zero position, and the "high voltage closing" button cannot be started)
(4) Gently press the "High voltage closing" button, the "High voltage closing" indicator light (red) lights up, and slowly adjust the voltage adjustment knob to the required voltage value for testing.During the test, the voltage display meter indicates the test voltage value, in kV;0.75 times voltage display Table 11 indicates 75% of the test voltage value, in kV;The current display table 7 indicates the test current value, in uA.
(5) Press the 0.75 times voltage display latch button during the test of the test object, the display value of the 0.75 times voltage display meter will be locked, and it is inconvenient to maintain the display value, so that it can be used as the reference voltage conveniently during the zinc oxide arrester test.
(6) Press the timing on button at any time to start the time relay. When the timing reaches the preset time, the buzzer will give an alarm and cut off the high-voltage output.
(7) During the test, if the load current exceeds 0-10% of the rated output current of the instrument, the "over-current" indicator will be on to protect the test object and instrument from damage.
(8) During the test, if the test voltage exceeds 0-10% of the rated output voltage of the instrument, the "over-voltage" indicator light will be on to protect the test object and instrument from damage.
(9) After the test, turn the voltage adjusting knob counterclockwise to the zero position, and the voltage display meter slowly returns to the zero position.When the three display meters display zero value, gently press the "High Voltage Off" button. At this time, the "High Voltage On" indicator (red) is off, and the "High Voltage Off" indicator (green) is on. Then turn off the power switch.
(10) When the capacitance of the tested object is very large, the output voltage display meter cannot return to zero after the voltage adjustment knob is turned to the zero position and is adjusted to the zero position, press the "High voltage opening" button first, and then turn off the machine.Then use the discharge rod to discharge the tested object, and then remove the wiring of the tested object.
Protection setting
The instrument is equipped with overvoltage protection, overcurrent protection and internal power protection. The overvoltage protection and overcurrent protection can be manually set by external personnel, while the power protection has been determined when the instrument leaves the factory, and cannot be determined by external personnel.
(1) Overvoltage protection
During the test, if it is not necessary to set, the specified voltage knob can be turned clockwise to the maximum. At this time, the overvoltage protection acts when the rated output voltage is exceeded, and the overvoltage protection indicator light (yellow) is on.If it is necessary to set the overvoltage protection value, before the test, the test object can be disconnected, the voltage setting knob can be turned clockwise to the maximum, and then the voltage can be boosted to the required voltage value according to the above operation process. When the voltage setting knob is turned counterclockwise to the overvoltage protection value and the overvoltage protection indicator light (yellow) is on, the overvoltage protection value is set.Then turn off the power switch, use the grounding rod to ground and discharge the high voltage, connect the test object to test, and when the test voltage exceeds the set value, the high voltage will be automatically cut off, and the overvoltage protection will act.
(2) Overcurrent protection
During the test, if the setting is not required, the current setting knob can be turned clockwise to the maximum. At this time, the overcurrent protection acts when the rated output current is exceeded, and the overcurrent protection indicator light (yellow) is on.If it is necessary to set the overcurrent protection value, before the test, connect the tested object, turn the current setting knob clockwise to the maximum, and then press the above.[2]
Simple troubleshooting
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1. When the power switch is turned on, the digital display meter on the control box does not light up
Please check the power supply wiring and all fuse tubes. If the fuse tube is damaged, please replace it with a new tube according to the amperage marked beside the fuse tube socket.
2. If the power switch is turned on, the digital display indicator will be on, and the high-voltage display lamp (green) will not be on, so the high-voltage can not be added.
① The fault display "return to zero" light is on.
If there is no return to zero position, please turn the high-voltage output adjusting knob and fine adjustment knob counterclockwise to return to zero position until the "return to zero" light is off, and then the high-voltage can be added.
② There are two phenomena when the fault display "Others" light is on: 1. grounding protection, 2. disconnection protection.
a) The grounding wire may not be properly connected, or the grounding wire may not be reliably grounded.Please connect the reliable ground wire, turn off the power and restart.
b) It may be that the cable connecting the control box and the high-voltage tower is not connected properly. Please turn off the power supply and restart after connecting the cable.Or this fault will occur when the welding heads at both ends of the cable are desoldered. Please weld the welding heads at both ends of the cable, turn off the power and restart.
c) It is possible that one of the wire ends in the control box is disconnected, please re weld it, turn off the power and restart it.
3. Everything is normal, but it is protected in the process of not rising to the rated output voltage
① The fault display "overcurrent" light is on.
a) The test object is short circuited or the leakage current is too large.
b) When the capacitance load is large, the voltage rise is too fast.Turn off the power supply, restart, and slow down the boosting speed.
② The fault display "overvoltage" light is on.
The overvoltage protection setting knob is not set at the maximum position. Please turn it clockwise to the maximum position, turn off the power and restart.
4. When a short circuit occurs under the high voltage of the test object, due to the high short circuit current, it is possible to turn on all fault indicators, which is normal. Please restart after troubleshooting the test object.
5. After the fault of the tested object is eliminated, the fault display lamp is still on, and the high voltage cannot be added.
The power switch is also a fault protection reset switch. Please turn off the power switch and restart it to boost the voltage.
6. If the number of the voltmeter fluctuates greatly, please check whether the 7-pin shielding mesh head and the central shielding wire head of the aviation plug at both ends of the connecting cable are disconnected. If they are disconnected, please weld them properly.[3]
Related concepts
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1) Rated output voltage: under the specified working conditions, the high-voltage output terminal of the DC high-voltage generator is connected to the tested object through the current limiting resistance. When the tested object passes the rated output current and the DC high-voltage pulse meets the requirements, the maximum DC voltage is called the rated output voltage.
2) Rated output current: under the specified working conditions and within the specified continuous operation time, the maximum current that the DC high-voltage generator can output under the condition that the output voltage and its pulsation meet the requirements is called the rated output current.
3) Rated output power: when rated output voltage and rated output current occur at the same time, the product of these two rated values is called rated output power.
4) DC high-voltage pulsation: pulsation refers to the periodic pulsation of the arithmetic mean value of DC high-voltage.The amplitude of pulsation refers to half of the difference between the maximum value and the minimum value.The fluctuation factor is the ratio of the fluctuation amplitude to the arithmetic mean value.
5) DC high voltage random fluctuation: DC high voltage random fluctuation is that the DC high voltage output terminal fluctuates with the influence of AC power supply voltage.The random fluctuation amplitude refers to the random variation of the arithmetic mean value of DC high voltage.
6) DC high-voltage voltage drift: DC high-voltage voltage drift refers to the drift value of DC high-voltage within a certain period of time when the DC high-voltage generator is under the condition of resistive load and the DC high-voltage regulator is placed at the rated voltage position when the power supply voltage is unchanged.[3]
