The insulation characteristics of transmission lines are important indicators for the safe operation of the power grid. In recent years, the corridors of power transmission and transformation lines have become increasingly dense, and many ultra-high voltage lines use double circuit transmission lines on the same tower. The spacing between different lines in the corridors is close, and even cross over. When the line needs maintenance or testing, and the operating line cannot be powered off, induction electricity of several thousand volts to tens of thousands of volts will be generated on the maintenance line. Under strong interference, traditional insulation resistance testers cannot meet the insulation testing requirements of power lines, including imported insulation resistance meters that cannot function properly and may even be burned out.

To ensure the safety of line insulation, existing methods mainly use infrared manual inspection or helicopter inspection. Infrared inspection can only qualitatively detect more serious leakage hazards, such as insulators, but cannot quantitatively obtain the insulation resistance value of the line, making it difficult to detect insulation hazards in advance. The efficiency of manual inspection is extremely low, the cost of helicopter inspection is high, and only qualitative inspection can be carried out. These methods cannot obtain the insulation resistance value of the line. When testing other equipment in ultra-high voltage and extra high voltage substations, the surrounding live lines or equipment will generate strong induced electricity on the tested equipment, seriously affecting insulation testing. Accurate insulation testing under strong induction conditions is a common challenge faced by both line insulation testing and substation maintenance.

To solve the problem of insulation resistance testing of transmission lines under strong induction conditions (such as multiple circuits on the same tower or crossing lines, with one circuit running live and the other circuit undergoing power outage maintenance), our company has developed and produced the KD7688 anti-interference transmission line insulation resistance testing device based on years of accumulated insulation anti-interference technology and joint projects with relevant departments. This provides a safe, effective, and convenient equipment and means for conducting line insulation testing under strong induction conditions.

The KD7688 anti-interference line insulation resistance testing device can effectively reduce the power frequency induced voltage, suppress high-frequency voltage, and load the DC high voltage of the insulation resistance test on the tested object through this device, thereby ensuring the authenticity of the insulation test. At the same time, the anti-interference auxiliary device can also measure induced electricity by dividing the voltage through a filtering network, and play a high-voltage isolation role, separating the high-voltage area from the instrument operation area

The anti-interference ability of the insulation resistance meter is not less than 1000 volts, with both analog and digital displays, and can automatically measure insulation resistance, absorption ratio, and polarization index.

Strong anti-interference ability

The strong anti-interference auxiliary device KD7688 adopts special anti-interference technology, which can effectively reduce induced voltage and ensure the authenticity and effectiveness of insulation testing. The device can withstand an induced voltage of up to 30kV. Strong anti-interference insulation resistance meter KD7688, with a single insulation resistance meter capable of withstanding interference up to several thousand volts. It can automatically measure insulation resistance, absorption ratio, and polarization index. There are four rated voltage levels for routine measurement, 0.5kV/1kV/2.5kV/5kV. The test voltage for the external high-voltage auxiliary device is 5kV. The lightweight and strong anti-interference auxiliary device KD7688 weighs 7KG per device, and the strong anti-interference insulation resistance meter KD7688 weighs 8KG per device. Equipped with a portable instrument box, convenient to carry and practical.

High security

The complete set of equipment for strong anti-interference insulation testing consists of anti-interference auxiliary devices and insulation resistance meters. High risk induced electricity and personnel operation instruments are separated in space. During operation, the anti-interference auxiliary device is used to measure the magnitude of the induced electricity first, and the insulation resistance is continued to be measured under acceptable conditions, thus avoiding direct harm to equipment and personnel caused by strong induced electricity. In addition, the testing power supply comes directly from the insulation resistance meter, without the need for external high-power high-voltage equipment, greatly reducing the workload and other risks of on-site operations, making insulation testing safer under strong interference conditions.

It can effectively reduce the induced voltage and achieve an overall suppression capability of over 100 times.

The device has little impact on short-circuit current, and even after connecting the device, it can still achieve an equivalent short-circuit current of 5mA.

Multi section design, convenient for transportation, easy to upgrade and expand to higher levels of anti-interference.

Vertical use, effective separation of high and low pressure, high safety.

KD7688 anti-interference circuit insulation resistance auxiliary testing device

● Withstand voltage: 50kV

Anti interference voltage: 30kV

● Size: 1500mmX100mm (after assembly)

Weight: 15kg

KD7688 anti-interference circuit insulation resistance testing device host

● AC power supply: 220V ± 10%, 50/60 HZ, 20 VA

● Battery power supply: 16.8V lithium-ion rechargeable battery

During battery life