High voltage electrical substation in mountains - stock photo, High voltage electrical substation in mountains in Witzenberg Valley, Western Cape, South AfricaCredit: geoffsp/ iStock/ Getty Images Plus
Researchers from South Africa have developed a mathematical model to investigate the effect of voltage rise and reverse power flow on an electrical distribution network.
The authors, from Durban University of Technology, South Africa, reported in Scientific Reports that renewable distributed generation (RDG) into power systems are increasing. The researchers attributed this to energy policy regulation, increasing environmental concerns over fossil fuel usage, regular outages and blackout, inadequate access to the utility grid by rural communities, and the high price of electricity billing.
The team noted that the conventional power system has been intrinsically radial: power flows in one direction only — from a power plant to the transmission network, distribution network, to the point of use. The penetration of RDGs into power systems may cause problems such as voltage rise or over-voltage and reverse power flow.
However, the introduction of RDG changes the dynamic of the network because power flows may change significantly and potentially in both directions. The team’s model investigates this effect and includes an advanced algorithm to normalize the voltage rise and mitigate the reverse power flow problem when operating at a worst critical scenario of minimum load and maximum power output from RDG.
Future research will pursue an online communication model for the monitoring of voltage rise when it is out of limit for the continuous measurement of voltages, currents and phase shifts. This will be achieved through voltage quality analysers as well as an automation system with voltage sensors.
