Resistive Impulse Divider

Resistive voltage dividers have very good response parameters. Therefore they are used for measurements for full and front chopped lightning impulses or impulses voltages with steep wave fronts, also in the special condition it can be used for measuring DC.

The transformation ratio and transfer behavior of resistive divider fulfils the IEC 60060-2 and GB/T16927.2-1997 requirements, in particular those with respect to measuring accuracy and dynamic behavior. The divider components are designed in such a way that the transfer errors are negligible for the lightning impulse shapes.

Resistive voltage dividers are generally used when an additional capacitance in the test circuit is not permissible due to the slowdown effect on the rise time. Therefore it can’t be used without any capacitive load in the test circuit.

Design

The high voltage resistors made of CrNi wire are anti-inductively wound. For dividers with a rated lightning impulse voltage above 200 kV the high voltage resistors are housed in cylinders made from glass fibre enforced epoxy resin. For these dividers the pure ohmic divider comprises also an external damping resistor.

Above 150kV rated lightning impulse voltage the dividers are equipped with toroidal HV electrodes to guarantee corona-free operation. The secondary unit is fitted with LEMO connector. It consists of resistors of low inductance arranged in a coaxial design. The unit is fixed at the bottom of the divider and can easily be disassembled.

The voltage divider is designed for indoor design. Dividers above a rated lightning voltage of 200 kV are erected on a four-arm base equipped with castors.