Microgrids are increasingly being considered to
provide electricity for the expanding energy demand in the grid
distribution network and grid isolated areas. However, the technical
challenges associated with the operation and controls are immense.
Management of dynamic power balances, power flow, and network
voltage profiles imposes unique challenges in the context of
microgrids. Stability of the microgrid during both grid-connected and
islanded mode is considered as the major challenge during its
operation. Traditional control methods have been employed are based
on the assumption of linear loads. For instance the concept of PQ,
voltage and frequency control through decoupled PQ are some of
very useful when considering linear loads, but they fall short when
considering nonlinear loads. The deficiency of traditional control
methods of microgrid suggests that more research in the control of
microgrids should be done. This research aims at introducing the dq
technique concept into decoupled PQ for dynamic load demand
control in inverter interfaced DG system operating as isolated LV
microgrid. Decoupled PQ in exact mathematical formulation in dq
frame is expected to accommodate all variations of the line
parameters (resistance and inductance) and to relinquish forced
relationship between the DG variables such as power, voltage and
frequency in LV microgrids and allow for individual parameter
control (frequency and line voltages). This concept is expected to
address and achieve accurate control, improve microgrid stability and
power quality at all load conditions.
Sida from Sweden