Affiliations: [a] State Key Laboratory of Power Transmission Equipment and System Security and New Technology, College of Electrical Engineering, Chongqing University, Chongqing, China | [b] Postdoctoral workstation of Yunnan power grid corporation, Kunming, Yunnan, China | [c] Kunming subsidiary of Yunnan Power Grid Corporation, Kunming, Yunnan, China
Correspondence:
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Corresponding author: Bing Gao, State Key Laboratory of Power Transmission Equipment and System Security and New Technology (Chongqing University), College of Electrical Engineering, Chongqing University, Shapingba District, Chongqing 400044, China. E-mail:20141102022@cqu.edu
Abstract: The operation environment of electric power cables
undergoes more and more natural damages, such as earthquake, flood which
would result in the change of unit capacitance and inductance of power
cables, as well as the reactive power. In this paper, a method of
``distributed model'' based on Poynting vector and space-stepping finite
difference frequency domain (FDFD) is proposed to calculate the reactive
power of power cables. Comparing with the method of ``lumped model'', it can
calculate the reactive power of power cables without computing the unit
capacitance and inductance which are difficult to get, especially when the
cable trench is fill with ponding, sludge and collapse. Calculation of the
reactive power has been carried out in consideration of eccentric and water
infiltration cases, and results indicate that ponding environment will lead
to a substantial increase of capacitive reactive power. Capacitive reactive
power increase with cable eccentricity degree; when cables suffer both water
ingress and a 2.5 mm eccentricity degree, the increased capacitive reactive
power will reach 51.98%.
Keywords: Poynting vector, FDFD, eccentric cable, water infiltration, reactive power
