HSW Steep Wave Voltage Divider (Fast Response)

HSW-600 Steep Wave Device

Main Parameter
Nominal voltage: ±600kV
600kV Quick Response Resistance Voltage Divider can meet with steepness range of (1000~3000)kV/ms, overshoot is adjustable
High voltage arm resistance: approx 2kΩ
HV Arm Resistance: 2000Ω;
LV Arm Resistance: 5Ω;
2 matching resistor: 70Ω and 75Ω;
Voltage Ratio:1000:1
response time < 5ns
Stability time of step response : Ta≤100ns
Uncertainty of scaling factor: Kε<1.0%
Overshoot of partial step: b ≤ 20%

Structure:
Single stage with one low voltage arm resistor .
It is removable with a grading ring on the top .

Steep Voltage Divider Principle Diagram:

Steep Voltage Divider in Impulse Voltage Test System:

Steep Voltage Divider square-wave source waveform:


Steep Voltage Divider square-wave response waveform:(Rectangle method)


Question 1:
When the steep front impulse voltage test, which divider will User use?
Answer: for Insulator imulse test, there is requirment of steep front impulse test; when do steep impulse test, we should move the impulse voltage divider, and connect the steep voltage divider in parallel woth the test object. We should use the steep voltage divider. But the impulse voltage divider should also be a configuration in the impulse test system, as User will need it when standard lightning impulse 1.2/50us or standard switching impulse 250/2500us waveform testing & measuring.  

Question 2:
How the get the steepness on the insulator when impulse voltage testing?
Answer: According to IEC/ANSI/IEEE, normally there are three differents kind of steepness requirement e.g. 1000kV/us, 1500kV/us, 2500kV/us; the porcelain insulator has a higher requirement on the steepness. So normally when user need to test porcelain insulator, we will proposal a higher voltage impulse generator then composit insulator or glass insulator. 
   The steepness has a positive corelation with the test voltage; and a negative corelation with the impulse steep front time. 
   But we can not raise the impulse voltage infinite, as the impulse generator output voltage also limit by the output efficiency. The other way to raise the steepness is shorten the impulse front time. 

In order to verify the effectiveness of steep-front impulse voltage testing in finding the internal faults of composite insulators, some insulators with faults are modeled which include conductive channel, semi-conductive airy channel and partial little air bubbles that occur separately at different places. A steep-front wave impulse voltage test (steepness of wave front is 1000-4000 kV//spl mu/s) is respectively made for these faulty and normal insulators. At the same-time the internal electric field intensity and its distribution in the insulator is calculated by making use of infinite element analysis software in order to test whether breakdown has occurred. The result is consistent with the experimental one. The final result shows that steep-front wave impulse voltage testing plays a very effective part in finding severe faults of the insulators.