Power flow control in city center infeed

Power flow control is needed to feed power into cities for different reasons: to ensure optimum power flow in the system, to recover from emergency conditions, to reduce reactive power flow, and to reduce loop flows when the system topology is built up with rings. There are also other reasons, for example, to limit the short-circuit currents, to improve the stability limit, or to increase the loading of lines close to their thermal capabilities. This paper discusses possible solutions to control power flow to city centers infeed. It also presents a case study where the power flow issue has been addressed. The study indicates that the HVDC alternative seems to be a more favourable solution than the other alternatives studied.