TITLE:
Simulation of Power Flow and Protection of a Limited Bus Grid System with Injected Solar Power
AUTHORS:
Nader Barsoum, Chai Zen Lee
KEYWORDS:
Grid Systems; Solar Power; Overvoltage; Overcurrent Relay; Bi-Directional Inverter; Relay Current Setting
JOURNAL NAME:
Energy and Power Engineering,
Vol.5 No.1,
January
9,
2013
ABSTRACT: In recent years, injection of renewable energy such as solar power
into the power grid is increasing. However, inclusion of large-scale
intermittent-type renewable energy requires better management in proper
understanding of grid’s variable characteristics and its protection systems. In
this paper, the investigation on overvoltage issue is illustrated. Overvoltage
in distribution feeder occurs when large amount of solar power is injected at
low power demand. Another investigation is on false operation of overcurrent
relays due to reverse power to the 33 kV loads. The potential solutions to the
two issues are illustrated in the small-sized power grid system using
bi-directional inverters on AC buses in charging battery banks and adjusting
the relay current settings. The benefits of solar power injection are
illustrated whereby output power from generators is decreased and transmission
losses are reduced. Electrical Transient Analysis Program (ETAP) was used for
investigations.