Compensation in Complex Variables for Microgrid Power Flow

Abstract

Abstract-The solution of the distribution network power flow in practical applications is based either on the forwardbackward sweep method for radial networks, or the current injection method for meshed networks. While the power flow in microgrids that operate in grid-connected mode could be resolved using the above approaches, their operation in island mode would require simulating local generation droop controllers for sharing the complex power load and network loss amongst the generators. This letter proposes a complex power compensation approach, which is based on Wirtinger calculus, for extending the applicability of practical distribution power flow methods to microgrids operating in island mode. Supporting numerical results are reported on microgrids with up to 3139 nodes.

Nested backward/forward sweep algorithm for power flow analysis of droop regulated islanded microgrids

“…A 160‐bus test system is selected to analyse the performance of NBFS, NTR, and MNR. The system data of this test system is adapted from [23]. In NBFS, the calculation procedure of matrices BIBC and BCBV are modified for the weakly‐meshed islanded system as suggested in [39].…”

“…In [19], a Gauss–Seidal‐based approach is proposed to solve the power flow problem of small‐size islanded MGs. In [23], it is mentioned that the performance of the power flow method proposed in [19] does not work on the larger systems. In [20], an improved evolutionary algorithm‐based load flow technique is proposed to solve the power flow problem of islanded MGs.…”

Power flow calculation based on local controller impedance features for the AC microgrid with distributed generations

“…Power flow calculation based on Newton-iterative method of the microgrid consisting of various DGs was widely researched in existing the literature [10][11][12][13][14][15][16][17][18][19][20]. From the view point of the distributed sources power fluctuation, the constant model under the maximum power point tracking (MPPT) was embedded into power flow calculation to deal with wind power fluctuation [10].…”

“…Thus, the global power flow calculation approach where the transmission and distributed power systems were regarded as a whole, was investigated [14]. Recently, some scholars extensively researched the power flow calculation based on modified Newton-iterative method of the AC microgrid dominated by power electronic converter adopting droop control strategy [15][16][17][18][19]. Within the context of the features of the AC microgrid operating in an islanded mode in which the system frequency was no longer fixed, the slack bus could not be applied to power flow calculation.…”

“…What is more, the power flow calculation for AC/DC microgrids considering virtual impedance was studied [16]. Meanwhile, the modified forward-backward sweep method for radial networks and the current injection method for meshed networks were proposed by simulating local generation droop controllers [17]. Then, the power flow calculation method was extended into the droop and isochronously controlled AC microgrids [18].…”