• Energy Research

Nanosecond-level transient electromagnetic disturbance (TED), including very fast transient overvoltage caused by operation of disconnectors, high-altitude electromagnetic pulse, and many other fast transients may interfere or even damage the electrical equipment. As one of the main overvoltage protective equipment, the protective performance of metal-oxide surge arresters (MOAs) under nanosecond-level TED should be investigated and then compared with that under microsecond-level TED, especially the lightning impulse. Based on a testing platform containing a 400-kV pulse generator with adjustable rise time from 5 to 100 ns, the behaviors of nonlinearity, fast impulse response, and converting impedances of three types of 10-kV MOAs under TED with different rise time were explored experimentally in this article. The peak residual voltages of 10-kV MOAs under TED with the rise time of 5 ns at 5 kA are 50.2–60.7% higher than those under the lightning impulse. The rise time of TED has significant influence on the peak voltage and impedance converting behaviors of MOAs. A circuit model of 10-kV MOAs under nanosecond-level TED is built and validated by experimental results, which can be applied in insulation coordination and design of protective devices against TED.

Nanosecond-level transient electromagnetic disturbance (TED), including very fast transient overvoltage caused by operation of disconnectors, high-altitude electromagnetic pulse, and many other fast transients may interfere or even damage the electrical equipment. As one of the main overvoltage protective equipment, the protective performance of metal-oxide surge arresters (MOAs) under nanosecond-level TED should be investigated and then compared with that under microsecond-level TED, especially the lightning impulse. Based on a testing platform containing a 400-kV pulse generator with adjustable rise time from 5 to 100 ns, the behaviors of nonlinearity, fast impulse response, and converting impedances of three types of 10-kV MOAs under TED with different rise time were explored experimentally in this article. The peak residual voltages of 10-kV MOAs under TED with the rise time of 5 ns at 5 kA are 50.2–60.7% higher than those under the lightning impulse. The rise time of TED has significant influence on the peak voltage and impedance converting behaviors of MOAs. A circuit model of 10-kV MOAs under nanosecond-level TED is built and validated by experimental results, which can be applied in insulation coordination and design of protective devices against TED.

High-altitude electromagnetic pulse (HEMP) has attracted considerable attention for its influence on electrical equipment. HEMP is divided into three parts: early time HEMP (E1), intermediate-time HEMP (E2), and late-time HEMP (E3). Most studies focused on E1 alone, while few investigated others. However, the electrical equipment may be disturbed by more than one part since these three parts co-exist in a HEMP environment. The pulse current injection (PCI) test is an effective immunity test method for evaluating the sensitivity and susceptibility of electrical equipment. To investigate the responses of electrical equipment excited by the consecutive E1 and E2 and compare with those under the individual E1 or E2, this paper builds a PCI platform that can carry out PCI tests with the consecutive E1 and E2 conducted current. To output the E1 current and the E2 current consecutively, which exhibit significant differences in the rise time (20 ns and 1.5 μs), peak current (2500 and 250 A), and full width at half maximum (FWHM, 500–550 ns and 3–5 ms), an E1&E2 coupler with a fast-closing high-current trigger switch is designed in this paper. Finally, some 10-kV epoxy insulators are tested in the developed platform, which shows the capacity of the proposed platform to test the immunity of electrical equipment with the consecutive E1 and E2 conducted current.

High-altitude electromagnetic pulse (HEMP) has attracted considerable attention for its influence on electrical equipment. HEMP is divided into three parts: early time HEMP (E1), intermediate-time HEMP (E2), and late-time HEMP (E3). Most studies focused on E1 alone, while few investigated others. However, the electrical equipment may be disturbed by more than one part since these three parts co-exist in a HEMP environment. The pulse current injection (PCI) test is an effective immunity test method for evaluating the sensitivity and susceptibility of electrical equipment. To investigate the responses of electrical equipment excited by the consecutive E1 and E2 and compare with those under the individual E1 or E2, this paper builds a PCI platform that can carry out PCI tests with the consecutive E1 and E2 conducted current. To output the E1 current and the E2 current consecutively, which exhibit significant differences in the rise time (20 ns and 1.5 μs), peak current (2500 and 250 A), and full width at half maximum (FWHM, 500–550 ns and 3–5 ms), an E1&E2 coupler with a fast-closing high-current trigger switch is designed in this paper. Finally, some 10-kV epoxy insulators are tested in the developed platform, which shows the capacity of the proposed platform to test the immunity of electrical equipment with the consecutive E1 and E2 conducted current.