Experimental and analytical investigation of the effects of single and multiple simulated lightning impulse currents on Metal-Oxide arrester blocks

• The 10/350 μs, steep wave and 2 ms rectangular impulse current are used to simulate the multiple lightning currents.
• The 10/350 μs impulse current is more severe than the 30/80 μs and 90/200 μs waveform current for high lightning duty test.
• Adopting larger ZnO block volume is an effective countermeasure both under single and multiple simulated lightning impulse currents.

In order to evaluate the performance of distribution network surge arresters more realistically, experimental and analytical investigation of the effects of single and multiple simulated lightning impulse currents on metal-oxide arrester blocks are carried out. Based on the analysis of existing test considerations, the 8/20 μs, 2 ms, 18/40 μs, 30/80 μs, 90/200 μs and 10/350 μs waveforms are used in single impulse current tests. In the multiple simulated lightning impulse currents tests, the first stroke is represented by 10/350 μs current, two subsequent strokes are represented by steep impulse current. The 2 ms rectangular impulse current is used to simulate the continuing current between stroke intervals. The test results on arrester blocks show that the 10/350 μs impulse current is more severe than the 30/80 μs and 90/200 μs waveform current for high lightning duty test under the same total absorbed energy condition. The surface flashover is an especial failure type under multiple simulated lightning impulse current tests, in the test current amplitude range. In the tested impulse interval time range, the time interval between strokes and the sequences of applying simulated impulse currents have almost no influence on the test results. Adopting larger ZnO block volume is an effective countermeasure both under single and multiple simulated lightning impulse currents.