Laboratory equipment is sometimes required to be calibrated in-situo and, in those scenarios, a pulse with frequency content exceeding the intended voltage source is needed. Moreover, for sensors that are highly attenuated, the calibration pulser must also be high voltage and very reproducible. Because the calibration pulser is intended to be used across a wide variety of experiments, it has...
As DC distribution system is developing rapidly, DC series arc fault has become a severe threat to safe operation of DC systems, since DC arc cannot extinct by itself. Moreover, DC series arc fault is difficult to be located, as the high frequency components of the arc current that are superimposed on the normal DC current cannot be extracted in some cases.
In this paper, a DC series arc fault...
Insulator surface flashover in vacuum due to pulsed and DC voltages has been thoroughly investigated, however the characteristics of surface flashover under multiple, short duration, high-voltage pulses are not well understood. A test stand has been developed at Los Alamos National Lab to further understand the effects of these conditions on the surface flashover strength of various...
Charges accumulated on the dielectric surface under DC field can lead to the overstress of the insulator due to the local field distortion, and may even initiate the surface flashover. Therefore, it is very necessary to study the surface charge accumulation and decay on polymer materials under DC voltage in order to get a theoretical basis for the design of DC composite insulators, considering...
The interruption performance of the Molded Case Circuit Breaker (MCCB) is important because this circuit breaker is closest protection device to consumer at the power distribution system. Basically, the interruption process of the MCCB is follows: when the fault current inflows, the trip unit detects it and operates stator to separate fixed electrode and moving electrode. Next, the arc...
In South China and Southwest China, 10 kV switchgear running under high temperature and high humidity, which is easier to induce switchgear partial discharge and then benefit the development of insulation fault, seriously affect the safe operation of power grid. At this stage, the protective measures of the switchgear insulation are limited to preventive measures and can’t protect the...
Nonlinear transmission lines (NLTLs) have been the subject of several studies that have shown their suitability in high-speed systems for a wide variety of applications as pulse compression, phase shifter, frequency multiplier, pulsed radar, battlefield communication disruption and also as a high power microwave source, holding in this case an additional way to generate radio frequency (RF)...
Epoxy resin of saturable reactor for UHVDC converter valves works in high temperature condition for long-term, and it also suffers from bipolar exponential decay pulse voltage erosion. In order to study the electro-thermal aging law of epoxy resin, the electro-thermal aging tests under pulse aging and sinusoidal aging are carried out. Pulse aging voltage is set as bipolar exponential decay...
Series arcs can occur in dc power systems whenever an energized wire supplying power to a load is interrupted. This can happen when a wire snaps abruptly or when a load connection becomes loose. Rather than ending in a simple open circuit, the inductance in series with the load establishes an arc, which inserts an additional impedance in between the source and load. The arc impedance decreases...
Transient plasma ignition (TPI) uses short (typ. nanosecond durations) high voltage pulses to generate highly non-equilibrium plasmas for combustion ignition. TPI allows lean-fuel combustion, improves ignition or combustion efficiency with potentially reduced emission [1,2]. This study evaluates the effect of pulse duration and rise time of >10 kV pulsed plasmas on the ignition plasma...
The phenomenon of metal removal from optical discs using pulsed power has been investigated. Pulsed power with 35.3 J/pulse was applied to concentric ring electrodes placed on the optical discs. The protective layer containing the metal layer was completely separated from the plastic substrate by about 30 shots of pulsed power. In order to clarify the mechanism of the metal removal, discharge...
There is a growing interest in the development of dielectric materials of high voltage breakdown strength used in compact pulse forming lines (PFLs) to drive high power microwave (HPM) sources and pulsed lasers. Therefore, much attention has been paid to polymer-ceramic composites, where normally the ceramic powders with high dielectric constant are dispersed in a polymer matrix of high...
Purpose/Aim
Partial discharge (PD) is the main reason for the insulation deterioration inside the electrical equipment. It’s necessary and valuable to locate the PD source occurred in electric power system timely and accurately. At present, ultrasonic array location method is an effective way in partial discharge detection. With high signal gain, strong anti-interference ability as well as...
