Control strategy of optimal power flow for microgrid islanded operation based on dynamic programming

Abstract

Renewable energy has become a significant
solution to replace conventional generation for
supplying electrical energy of nowadays microgrid
(MG), however, fluctuation and intermittency
resulted from uncertainty source and load demand
impact on power flow of system. This paper
presents the control strategy for optimal power flow
(OPL) of islanded MG by developing the
mathematical model. The MG consists of diesel
engine generator, energy storage system (ESS),
wind turbine generator (WTG), and photovoltaic
generator (PV). In the control system considered,
operation planning is realized based on profiles
such that the demand load, WTG power, and PV
power must be forecasted in short-period,
meanwhile the dispatch source (i.e., DEG) and ESS
need scheduling. The objective of the control
problem is to find the DEG output power and the
rated power of inverter for ESS by minimizing the
total cost of energy and using dynamic
programming that leads to the Hamilton-JacobiBellman equation. Experimental results are
presented, and show the effectiveness of optimal
control such that the generation allows demand
profile.