High voltage generator

Product introduction

The high-voltage generator, also known as the DC high-voltage generator, is the traditional name for the high-voltage power supply. It refers to the high-voltage power supply mainly used for insulation and leakage detection. There is no strict distinction between high-voltage generators. English: high voltage power supply Abbreviation: HVPS. The high-frequency DC high-voltage generator adopts a high-frequency voltage doubler circuit, the latest PWM high-frequency pulse width modulation technology, closed-loop adjustment, and a large voltage feedback, which greatly improves the voltage stability. Use high-power IGBT devices with excellent performance and their drive technology, and adopt special shielding, isolation and grounding measures according to the electromagnetic compatibility theory. The DC high-voltage generator realizes high-quality, portable, and can withstand the 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. Step-up, step-down, measurement and protection are fully automated. And manual intervention can be carried out during the automatic boosting process. Because it is fully electronic. It can be widely used in the AC withstand voltage test of cables, rotating machines and power capacitors.

The DC high voltage generator adopts intermediate frequency rectification and filtering technology, which solves the shortcomings of large ripple coefficient and unstable waveform of the power frequency DC high voltage generator. The latest research, design, and manufacturing of new technology products of DC high-voltage generators are suitable for electric power departments, power departments of factories and mining enterprises, scientific research institutions, railways, chemicals, power plants, etc. DC high voltage test for transformers, switches and other equipment is the most ideal replacement product in the new century. The intelligent DC high-voltage generator uses a new generation of PWM high-frequency pulse width modulation technology, adopts a high-end intermediate frequency voltage doubler circuit, high-performance closed-loop adjustment, and high-voltage large feedback, which greatly further improves the voltage stability. According to the national standard of "Portable DC High Voltage Generator General Technical Conditions" (ZGF24003-90), based on the original DC high voltage generator, it conforms to the principle of Nikko Electric's electromagnetic compatibility theory, and adopts the principle of special shielding, isolation and grounding measures according to the national standard law. And the method, the use of higher performance high-power IGBT devices and their driving technology, modern electronic high-tech chips, intelligent operation, is the smart DC high-voltage generator is more truly intelligent, portable, and further expand the range of withstand voltage Damage.

Features of the generator

The DC high-voltage generator is the latest research, design, and manufacture according to the requirements of the Chinese industry standard ZBF 24003-90 "General Technical Requirements for Portable DC High-Voltage Generators" , Is a new era of science and technology products-portable DC high-voltage generator, suitable for electric power departments, scientific research institutions, railways, chemical industries, power plants, large-scale enterprise power departments for zinc oxide arresters, magnetic blown arresters, power cables, generators, transformers , Switches and other equipment are subject to DC high voltage test and leakage current test.

Using pulse width modulation (PWM) technology, IGBT, and advanced electronic circuits and components, the output is not interfered by power grid fluctuations, and there are protective measures such as zero position, overcurrent, breakdown, and overvoltage. Regardless of over-current, breakdown, and over-voltage protection circuits can act quickly, effectively ensuring the safety of equipment and personnel. Its output adopts liquid crystal display, and its volume and weight are much lighter than the original KGF type, which is very suitable for on-site use. The newly designed "0.75U" LCD can directly display and lock the 0.75U1mA field test without manual calculation.

High precision and accurate measurement. Both the voltage and current meters are digitally displayed, the voltage resolution is 0.1kV, and the current resolution is 0.1uA. The voltmeter on the control box directly displays the voltage value added to the load sample. There is no need to add a voltage divider when using it, and the wiring is simple. The instrument has high and low voltage ends to measure the leakage current, and the high voltage end adopts a circular shielded digital meter to display, which is not afraid of discharge shock, has good anti-interference performance, and is suitable for on-site use.

High voltage regulation stability, smooth voltage regulation across the entire range, imported single multi-turn potentiometer for output voltage regulation, stable boost process, high regulation accuracy, and designed with coarse and fine adjustment functions. The voltage adjustment accuracy is better than 0.1%, the voltage and current measurement error is less than 1.0%, and the pulsation factor is better than 0.5%.

Technical conditions

Power supply: AC220V±10%, 50Hz±1%;

Output voltage indication accuracy: <level 1;

Ripple coefficient: ≤0.5%;

0.75 times output voltage indication accuracy: <1 level, with latch.

Conditions of use

Relative humidity: no more than 85% at 25℃, no condensation;

Working mode: intermittent use for 30 minutes;

Ambient temperature: -10 ~ 40℃;

Altitude: below 1500m.

Protection function

Internal overvoltage protection, internal overcurrent protection;

External overvoltage protection (protection voltage can be adjusted), external overcurrent protection or shock Wear protection;

Internal power protection;

Non-zero start protection;

Timed sound alarm.

Test product test

Connect the test product between the high-voltage output terminal and the ground terminal.

Turn on the power switch, and lightly press the "Start" button, the "Power" indicator (red) lights up, slowly adjust the voltage coarse adjustment knob and the voltage fine adjustment knob to test. The voltage display meter during the test indicates the test voltage value in kV; the 0.75 times voltage display meter indicates 75% of the test voltage value in kV; the current display meter indicates the test current value in mA.

During the test of the sample, press the 0.75 times voltage display lock button, the 0.75 times voltage display meter display value is locked, and it is inconvenient to maintain the displayed value, so it is convenient to do the zinc oxide arrester test. As a reference voltage. Press the timer on button at any time to activate the time relay. When the timer reaches the preset time, the buzzer will sound 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, and the over-current protection will prevent damage to the sample and the instrument.

After the test is over, adjust the voltage coarse adjustment knob and the voltage fine adjustment knob counterclockwise. After turning them 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 indicators show zero value, press the stop button lightly, the red indicator light will go out at this time, and then turn off the power switch. When the electric capacity of the tested product is large, after the coarse and fine voltage adjustments are adjusted to zero, the output voltage display meter will not return to zero for a long time, then press the stop button first, and then shut down. Then use a discharge rod to discharge the test product, and then remove the test product wiring.

Precautions

1. During the cable withstand voltage test, the voltage step-up process should be uniform and slow, and the step-down process should also be uniform and slow. At the same time, protection should be added to the high-voltage output end. Water resistance. Otherwise, the reverse voltage may damage the instrument.

2. When the instrument is tested, the grounding must be good, and the grounding grid or ground pile should be selected, and the test cannot be performed without grounding.

3. The staff who use the DC high-voltage generator must have professionals with a "high-voltage test certificate".

4. To use this instrument, the user must follow Article 168 of the "Electrical Safety Regulations" and install two obvious disconnect points before the working power supply enters the tester. When replacing the test product and wiring, the two power disconnect points should be clearly disconnected first.

5. Before the test, please check whether the grounding wires of all test wiring, control box, pressure doubler and test product are well connected. The grounding wire of the test circuit should be grounded at one point as shown in this manual.

6. For the discharge of large capacitor samples, ZS special discharge resistance rods are used to discharge the samples. When discharging, the discharge rod should not be brought into contact with the test product immediately. The discharge rod should be gradually approached to the test product. When there is a certain distance in the air gap, it will begin to discharge freely. There will be a hissing noise. When there is no sound, the discharge rod can be used to discharge. Finally, connect the ground directly. Discharge.

7. When the DC high voltage is 200kV and above, although the tester wears insulated shoes and is in an area beyond a safe distance, due to the influence of the spatial electric field distribution of the high voltage DC ion, it will cause several standing nearby There are different DC potentials on the human body. Test personnel should not shake hands with each other or touch the grounding body with their hands, otherwise there will be a slight electric shock. This phenomenon is more obvious in dry areas and winter, but due to the low energy, it will generally not cause harm to the human body.

8. The power supply of the ZS series portable ultra-light DC high voltage generator control box is AC 220V±10%, 50Hz. If the power supply is changed by 1/1 isolation or a spontaneous power supply is used on site, the power supply must be connected to the earth a little bit artificially.

Operation and steps

Preparation before operation

Connect the output cable socket of the control box and the voltage doubler device cable socket with a dedicated cable. This instrument is used by Check its integrity beforehand, the connecting cable should not be short-circuited or disconnected; the pressure doubler should be free of condensation; use a copper wire of 2.5mm2 or more to connect the control box ground to the grounding terminal of the pressure doubler and be reliably grounded.

Operation process

(1) Connect the test product between the high-voltage output terminal and the ground terminal.

(2) Plug in the power cord, turn on the power switch, the "high voltage sub" indicator (green) is on, the "high voltage close" indicator (red) is off; the voltage display meter and the current display meter, and 0.75 times voltage display meter shows zero value.

(3) Turn the voltage and current setting knobs clockwise to the end, and turn the voltage adjustment knobs counterclockwise to the zero position. (Note: the voltage adjustment knob is not in the zero position, and the "high pressure close" button cannot be activated)

(4) Lightly press the "high pressure close" button, the "high pressure close" indicator (red) lights up, adjust slowly Turn 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; the 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 lock button during the test of the sample, the display value of the 0.75 times voltage display meter will be locked, and it is inconvenient to maintain the displayed value, so it is very difficult to do the zinc oxide arrester test. Conveniently can be used as a reference voltage.

(6) Press the timing on button at any time to activate the time relay. When the timer reaches the preset time, the buzzer will sound an alarm and the high voltage output will be cut off at the same time.

(7) During the test, if the load current exceeds 0-10% of the instrument's rated output current, the "over-current" indicator will light up, and the over-current protection will prevent damage to the sample and the instrument.

(8) During the test, if the test voltage exceeds 0-10% of the rated output voltage of the instrument, the "overvoltage" indicator light will be on, over protection, to prevent damage to the sample and the instrument.

(9) After the test is over, turn the voltage adjustment knob counterclockwise to the zero position, and the voltage indicator slowly returns to the zero position. When the three indicators show zero values, lightly press the "High Voltage Min" button. At this time, the "High Voltage Close" indicator (red) is off and the "High Voltage Sub" indicator (green) is on, then turn off the power switch.

(10) When the capacitance of the tested product is large, after the voltage adjustment knob is turned to the zero position and the zero position is adjusted to the zero position, the output voltage display meter will not return to zero for a long time. "Press the button, and then shut down. Then use a discharge rod to discharge the test product, and then remove the test product wiring.

Protection settings

This instrument is equipped with overvoltage protection, overcurrent protection and internal power protection. The overvoltage protection and overcurrent protection can be set manually by the outside. The power protection is determined when the instrument leaves the factory and cannot be determined externally.

(1) Overvoltage protection

During the test, if you don’t need to set, you can turn the voltage setting knob clockwise to the maximum. At this time, the overvoltage protection will exceed the rated value. The output voltage is activated, and the overvoltage protection indicator (yellow) is on. If you need to set the overvoltage protection value, before the test, you can turn the voltage setting knob clockwise to the maximum without connecting the test product, and then boost the voltage to the required voltage value according to the aforementioned operation process, and then turn the voltage setting knob When it is turned counterclockwise to the overvoltage protection value and the overvoltage protection indicator (yellow) is on, the overvoltage protection value is set at this time. Then turn off the power switch, use a ground rod to discharge the high voltage to the ground, and connect the test product to test. At this time, 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 you don’t need to set, you can turn the current setting knob clockwise to the maximum. At this time, the overcurrent protection exceeds the rated value. The output current is activated, and the overcurrent protection indicator (yellow) is on. If you need to set the overcurrent protection value, before the test, you can connect the tested product first, turn the current setting knob clockwise to the maximum, and then press the aforementioned.

Simple troubleshooting

1. When the power switch is turned on, the digital display on the control box does not light up

Please check the power connection and all fuses, If the fuse is damaged, please replace it with a new one according to the amperage marked next to the fuse holder.

2. If the power switch is turned on, the digital display will light up, but the high voltage indicator light (green) will not light up, and high voltage cannot be applied.

① The fault display "return to zero" light is on.

If there is no return to zero position, please turn the high voltage output adjustment knob and fine adjustment knob counterclockwise to return to the zero position until the "return to zero" light is off, and then high voltage can be added.

② There are two phenomena when the fault display "other" light is on: 1. Grounding protection, 2. Disconnection protection.

a) The grounding wire may not be connected well, or the grounding wire may not be reliably grounded. Please connect a 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 and restart after connecting the cable. Or when the welding heads at both ends of the cable are unsoldered Start.

c) It is possible that a wire in the control box is disconnected and disconnected. Please re-solder, turn off the power, and restart.

3. Everything is normal, but the protection is in the process of not rising to the rated output voltage

①The fault display "overcurrent" light is on.

a) The test product is short-circuited, or the leakage current is too large.

b) When the load is large, the boost is too fast. Turn off the power, restart, and slow down the boost speed.

② The fault display "overvoltage" light is on.

The overvoltage protection setting knob is not placed at the maximum point, please turn it clockwise to the maximum point, turn off the power, and restart.

4. When the test product is short-circuited under high voltage, due to the large short-circuit current, it is possible to light up all the fault indicators. This is normal. Please remove the test product failure and restart.

5. After the failure of the test product is eliminated, the failure indicator is still on and high voltage cannot be applied.

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 you find that the number of the voltmeter fluctuates greatly, please check whether the 7-pin shielded mesh head and the center shielded wire head of the aviation plug at both ends of the cable are disconnected. If it is disconnected, please solder it.

Related concepts

1) Rated output voltage: Under specified working conditions, the high-voltage output terminal of the DC high-voltage generator is connected to the tested product via a current limiting resistor. The maximum DC voltage when the rated output current passes through and the DC high-voltage pulsation meets the requirements is called the rated output voltage.

2) Rated output current: The maximum current that the DC high-voltage generator can output under the specified working conditions and specified continuous operating time when the output voltage and its pulsation meet the requirements Is the rated output current.

3) Rated output power: When the rated output voltage and the rated output current appear at the same time, the product of the two rated values ​​is called the rated output power.

4) DC high voltage pulsation: pulsation refers to the periodic pulsation of the arithmetic average value of DC high voltage. The pulsation amplitude refers to half of the difference between the maximum value and the minimum value. The pulsation factor is the ratio of the pulsation amplitude to the arithmetic mean value.

5) DC high voltage random fluctuation: DC high voltage random fluctuation is the fluctuation of the DC high voltage output terminal with the influence of the AC power supply voltage. Random fluctuation amplitude refers to the random change of the arithmetic mean value of DC high voltage.

6) DC high-voltage voltage drift: DC high-voltage voltage drift means that the power supply voltage remains unchanged, 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 for a certain period of time The drift value of the internal DC high voltage.