Master control unit based power exchange strategy for interconnected microgrids

Abstract

Large remote area networks normally have self-sufficient electricity systems. These systems also rely on non-dispatchable DGs (N-DGs) for overall reduction in cost of electricity production. It is a fact that uncertainties included in the nature of N-DGs as well as load demand can cause cost burden on islanded microgrids (MGs). This paper proposes development of economic aspect for an interconnected MGs (IMG) system as part of large remote area network with optimized controls of dispatchable (D-DGs) which are members of master control unit (MCU). MCU analysis includes equal cost increment principle to give idea about the amount of power exchange which could take place with neighbor MGs in case of overloading situation. Sudden changes in N-DGs and load are defined as interruptions and are part of analysis too. Optimization problem is formulated on the basis of MCU adjustment for overloading or under loading situation and suitability of support MG (S-MG) in IMG system for power exchange along with key features of low cost and minimum technical impacts. Mixed integer linear programming (MILP) technique is applied to solve the formulated problem. The impact of proposed strategy is assessed by numerical analysis in MATLAB programming under stochastic environment.

Interconnected Smart Transactive Microgrids—A Survey on Trading, Energy Management Systems, and Optimisation Approaches

“…Further contributing to this field, the authors in [136] proposed the establishment of a power exchange strategy specifically for ISTMGs using decentralized optimization. Their strategy formed part of a larger remote area network and incorporated optimized dispatchable distributed generators (D-DGs) as integral members of a master control unit (MCU).…”

Market model for clustered microgrids optimisation including distribution network operations

“…Constraints (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29) represents the adjustment scenarios applied for overcoming emergency situation. p is chosen as the probability and is the time in which adjustment take place.…”

“…Constraint (28) guarantees that DGs generation is still less than load demand as V/f control was failed at first level so ESP power import is needed. Constraint (29) shows the permissible limit of system losses after adjustments for power factor correction.…”

“…Although in reality it is not possible but this assumption is made for the sake of complexity reduction and simplicity. Impedance data for MGs internal structure is taken from [29]. The nominal capacities of DERs existing inside MGs are shown in Table A of Appendix B while all costs data used in simulations is shown in Table 1.…”

“…The operation of ISP is assumed as a bi‐level stochastic process [27] so decision variables are divided into two groups. At first, actual realisation of supply and demand is done using power flow analysis based on modified Guass–Siedel iterative technique [28]. Once the uncertain scenarios have unfolded, further operational adjustments can be made according to the IOE decision.…”