Impulse voltage testing systems are designed produce impulse voltages that replicate lightning strokes (LI, 1.2/50 ), chopping lightning is another form of impulse voltages produced (LIC front time 1.2, chopped on the front, tail or crest ). It also produces switching surges (SI, 250/2500 ), All this is in line with IEC 60060-1 and IEC 60076-3 and on the other hand, IEC 62067, 60840 and 60502-1 when it comes to transformers and cables respectively. The full system comprises of a voltage divider, charging rectifier, impulse stages and a voltage measurement system. However, the standard system consist of a voltage generator and three components which are; the over voltage correction, chopping sphere gap and the voltage divider. It is used for testing gas-insulated switch gears, transformers, cables and arrestors among other high-voltage devices.
These systems have some special components for testing which include;
presence of shunts for measuring the impulse current, compensation for overshoot and ability for use on on-site application. The standard test system also has in place a digital MIAS transient recorder that delivers actual voltage measurements. It also offers varying features that can be used for controlling the system which is in addition to capturing and evaluating measurement values. Due to the fact that the MIAS does not offer any controls, the system comes with the software of the IPC. They can also come as current impulse generators used basically for testing the surge arrestor.
The systems are tested in factories in three lines namely; L, M and G. The level of voltage that can be generated depending on the system’s product line range between 10 KV to 5700 Kv (Li) / 4,500 KV (SI) with even some for upto for up to 1,900 KV (LI) in voltages being available for on-site testing.
The impulse voltage tests system has substantial benefits which vary from each other. Some of these varying benefits which have less or no disparity at all irrespective of the system series include; The design of most of these systems has been built in a somewhat compact manner that allows for saving space in the test bay. As a result of the low self inductance,the system tends to generates impulses with a low level of overshoot. On the other hand, If it is used together with the connection point, it can enhance saving of space and time. The test systems can also be used in research and training programs for testing materials in addition to their usage in factories and on-site testing.