ZGF Integrated DC Hipot Tester
Product Introduction
The ZGF Integrated DC Hipot Tester is specifically designed for detecting the electrical insulation strength and measuring leakage current in power devices. It employs a high-frequency voltage doubler circuit and integrates advanced PWM pulse width modulation technology along with a voltage-current dual closed-loop feedback system. Utilizing imported high-power IGBT devices and advanced drive technology, the tester achieves high voltage stability and extremely low ripple. Additionally, the adoption of imported high-frequency high-voltage rectifier diodes makes the double-pressure cylinder more compact and lightweight.
Product Characteristics
1. Stable Output Voltage – The instrument utilizes a high-frequency voltage doubler circuit combined with advanced PWM pulse width modulation technology and voltage-current dual closed-loop feedback. This significantly improves both power supply regulation and load regulation, resulting in high voltage stability and low ripple.
2. Comprehensive Protection – Fully equipped with protection functions including zero-start, over-voltage, over-current, and breakdown protection. The protection circuit employs nanosecond-level sensors for fast and reliable response, effectively ensuring the safety of both personnel and equipment.
3. 0.75U Function – Features an intelligent high-precision 0.75U one-button function. When pressed, the voltage and current automatically adjust to the 0.75U state, facilitating convenient testing of zinc oxide arresters.
4. Zero-Start Boost – The boost potentiometer starts from zero and uses an imported multi-turn potentiometer, ensuring a smooth boosting process with high adjustment precision.
5. Over-Voltage Setting – Over-voltage settings are configured using a digital dial switch, offering easy operation and high setting accuracy.
6. Integrated Design – Adopts a one-piece design with the host and voltage doubler housed in a single chassis. The use of imported high-frequency high-voltage rectifier diodes results in a compact voltage doubler, improved overall efficiency, and enhanced portability.
7. Reliable Performance – Key components utilize high-performance imported parts. The pressure roller is coated with specialized insulating materials, providing excellent electrical performance, strong moisture resistance, and no leakage.
8. Simple Operation – The instrument interface features clearly labeled function buttons with a reasonable layout, making it easy to learn and operate.
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Technische Parameter
| Spezifikation | 60/2 | 60/3 | 60/5 | 120/2 | 120/3 | 120/5 |
| Rated voltage（kV） | 60 | 60 | 60 | 120 | 120 | 120 |
| Rated current（mA） | 2 | 3 | 5 | 2 | 3 | 5 |
| rated power（W） | 120 | 180 | 300 | 240 | 360 | 600 |
| Machine quality（kg） | 9 | 10 | ||||
| Machine volume（mm3） | 465*390*190 | 565*390*190 | ||||
| Double cylinder height（mm） | 440 | 535 | ||||
| Genauigkeit der Ausgangsspannung | ±(1,0 %Lesung ± 2 Wörter) | |||||
| Ausgangsstromgenauigkeit | ±(1,0 %Lesung ± 2 Wörter) | |||||
| Welligkeitskoeffizient | ≤0.5% | |||||
| Arbeitsweise | Gelegentlicher Gebrauch, Nennlast 30 Minuten | |||||
| Überlastfähigkeit | Die Leerlaufspannung kann 10 Minuten lang 10 % der Nennspannung überschreiten | |||||
| Der maximale Ladestrom beträgt das 1,25-fache des Nennstroms | ||||||
| power supply：AC220V±10% 50Hz | ||||||
| Arbeitsumfeld | temperature：-10-40℃ | |||||
| Relative Luftfeuchtigkeit: nicht mehr als 85 % bei einer Raumtemperatur von 25 °C (keine Kondensation) | ||||||
| Höhe: unter 1500 Meter | ||||||
Core Comparison: DC Hipot vs. AC Withstand Voltage Equipment
Aspect | DC High-Voltage Generator | AC Withstand Voltage Equipment (Power-Frequency / Series Resonant) |
Nature of test voltage | Constant, non-pulsating DC electric field | Alternating electric field with varying amplitude (50 Hz or equivalent) |
Focus of insulation stress | Primarily tests dielectric strength (breakdown); effective for detecting end-insulation defects and moisture ingress | Tests both dielectric strength and dielectric loss; can detect internal voids, mechanical damage, and other overall defects |
Equipment weight | Extremely light (high-frequency inverter technology; main unit weighs only a few kilograms) | Extremely heavy (power-frequency transformers are bulky; series-resonant units are lighter but still weigh over 100 kg) |
Capacity & power supply | Small capacity; only needs ordinary 220 V supply | Large capacity (high apparent power); often requires a highcapacity supply or generator on site |
Damaging effect (residual effect) | Has a “cumulative effect” – space charge accumulates inside the insulation under DC, accelerating ageing after repeated tests (especially for XLPE cables) | No polarity accumulation, but poses thermal damage risk to organic insulation; breakdown points are severely carbonised |
Leakage current reading | Microampere level (μA) – accurately reflects moisture ingress and degradation trends | Milliampere level (mA) – cannot be interpreted alone; must be combined with dielectric loss factor (tan δ) |
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Main application scenarios
DC high voltage generator is the core equipment for preventive testing in power systems, mainly used to test insulation strength, rather than providing energy:
Power cable test: Conduct DC withstand voltage test and leakage current measurement on cross-linked polyethylene (XLPE) power cables (note: currently, ultra-high voltage cables are mostly subjected to AC withstand voltage using variable frequency series resonance, but DC generators are still widely used in the detection of medium and low voltage cables).
Insulator/bushing test: detect the leakage current on the surface of high-voltage line insulators, bushings, etc., and determine the degree of moisture or pollution.
Zinc oxide lightning arrester test: Apply a DC reference voltage (such as U1mA) to the lightning arrester to detect the aging of its nonlinear resistor.
Research and production: used for factory withstand voltage testing of high-voltage capacitors, high-voltage motors, transformers and other equipment.
Frequently Asked Questions
Q1: What are the most common safety hazards that occur during the testing process of a DC high-voltage generator?
A1: Mainly includes high-voltage electric shock, insulation breakdown, fire, and equipment failure. Be sure to strictly follow the safety operating procedures.
Q2: What is the impact of the output voltage ripple coefficient of the DC high-voltage generator on the test?
A2: The higher the ripple coefficient, the greater the fluctuation of the output voltage, which may lead to inaccurate test results, especially in precision tests that require extremely high voltage stability.
Q3: How to choose a DC high-voltage generator suitable for cable withstand voltage testing?
A3: It is necessary to calculate the required test voltage and capacity based on parameters such as cable length, cross-sectional area, and insulation level, and consider a certain margin.
Q4: Can a DC high-voltage generator be used for AC withstand voltage testing?
A4: Normally, DC high-voltage generators can only be used for DC withstand voltage tests. If an AC voltage withstand test is required, an AC high-voltage generator should be used.
