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Keywords

photovoltaic access; system short-circuit; distribution network lightning arrester; complex operatingcondition; thermal charge transfer value

Abstract

In recent years, a large number of photovoltaic power sources have been connected to the distribution network, and the line voltage fluctuations caused thereby have become a research hotspot.However, at present, there is insufficient understanding of the complex operating conditions formed by the superposition of overvoltage generated by short-circuit faults in the distribution network and system voltage fluctuations caused by photovoltaic access, as well as a lack of knowledge about the fault mechanisms of distribution network lightning arresters and other equipment under such operating conditions.To solve the above problems, a simulation calculation model for substation overvoltage with photovoltaic access is established.Under the condition of a superimposed system short-circuit overvoltage, the impact of small system disturbances on the voltage at the photovoltaic grid-connected point during photovoltaic access is analyzed through simulation.It is found that after photovoltaic access, under the same fault conditions, the overvoltage amplitude at the grid-connected point is larger, and the duration is longer.By taking actual fault cases as examples, it is found that if the voltage amplitude increases by 23%, the duration will be extended by 3.5 times.The voltage waveform under complex operating conditions is applied to the constructed calculation module for the current-carrying capacity of the lightning arrester, and its impact on the thermal charge transfer value of the lightning arrester is analyzed.Simulation results under typical case conditions show that before and after photovoltaic access, under the condition that the line-to-line short-circuit fault triggers the operation of the lightning arrester, the thermal charge transfer value increases from 0.65 C to 1.85 C, and the absorbed energy increases by 1.8 times, which is sufficient to cause thermal collapse of the lightning arrester.Relevant research has achieved a deeper understanding of the complex operating conditions of distribution network lightning arresters with a large number of photovoltaic accesses, and provides a method for guiding the selection of distribution network lightning arresters.

DOI

10.19781/j.issn.1673-9140.2025.05.030

First Page

315

Last Page

324

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