Microgrid In Islanded Mode Research Articles

Coordinated Control Strategy for Microgrid in Grid-Connected and Islanded Operation

AbstractAs usual, the microgrid operates in grid-connect mode, but, when a fault occurs in the upstream grid, it should disconnect and shift into islanded operation mode. In grid-connect mode, the controlling power at the PCC is necessary management function rather than the frequency and voltage. However, the controlling the frequency and voltage is asked in islanded mode. To achieve these management goals appropriately, the cooperative control strategy among microsources is needed. This supervisory control action is executed at MMS. In this paper, the cooperative control strategy of microgrid components is presented and the management performance is evaluated by using microgrid pilot plant. The pilot plant consists of the PV, PV/Wind Hybrid system, BESS, diesel generators, and RLC loads, which are connected to 380V low voltage lines. The test results show that the proper control strategy can ensure stability of microgrid in islanded mode and maintain the power at the PCC at desired value successfully.

Design methods investigation for residential microgrid infrastructure

AbstractIn this study a residential community in Phoenix was selected as the basis to develop design methods for a residential microgrid. A microgrid model was built using computer based software. Photovoltaic (PV) modules, microturbines, and fuel cells were chosen as the distributed energy resources (DERs) for the model. The optimal residential microgrid system configuration was sorted out according to the least net present cost (NPC), and the least cost of energy (COE) of the designed microgrid system. The results indicate that the COE of the designed microgrid in island mode is expensive, although it is more environmentally friendly compared to the grid. The purpose of combined cooling, heating, and power (CCHP) is achieved by utilizing the exhaust heat from microturbines to provide daily hot water consumption while cooling demand is achieved through the connection of adsorption chillers to microturbines. Sensitivity analysis shows that natural gas price escalation and price reduction of DERs significantly impact COE and NPC. Copyright © 2010 John Wiley & Sons, Ltd.

Performance Evaluation of Microgrid Management Function in KERI pilot plant

As usual, the microgrid operates in grid-connect mode, but, when a fault occurs in the upstream grid, it should disconnect and shift into islanded operation mode. In grid- connect mode, the controlling power flow at PCC is necessary management function rather than the frequency and voltage. However, the controlling the frequency and voltage is asked in islanded mode. To achieve these management goals appropriately, the cooperative control strategy among microsources is needed. This supervisory control action is executed at MMS. In this paper, the cooperative control strategy of microgrid components is presented and the management performance is evaluated by using microgrid pilot plant. The pilot plant consists of the PV, PV/Wind Hybrid system, BESS, diesel generators, and RLC loads, which are connected to 380V low voltage lines. The test results show that the proper control strategy can ensure stability of microgrid in islanded mode and maintain the power flow of PCC at desired value successfully.

96/1649 Optimal dynamic load shedding using a Newton based dynamic algorithm

Compared with frequency regulation by wind generation system, a battery energy storage system (BESS) is a better alternative for providing frequency regulation and inertial response in a faster, more accurate and flexible manner. So, participation of BESS in an islanded microgrid frequency regulation can assist renewable distributed generators (DGs) in operating at their maximum efficiency without excessive power curtailment. Furthermore, a BESS can mitigate the frequency variation with a faster response when the frequency disturbance occurs in an islanded microgrid. If the energy capacity of the BESS is limited, a wind turbine generator can gradually take over the mid-to-long term frequency regulation tasks through emulated droop response and Automatic Generation Control (AGC) control.In this chapter, we will focus on the coordinated frequency regulation and control of BESSs and wind power in the islanded mode of microgrid or microgrid cluster. The objective of microgrid frequency regulation is to regulate the frequency of an islanded microgrid to the specified nominal value in the event of frequency disturbance, and at the same time to maintain the tie-line power interchange among different microgrids within a microgrid cluster, or between two virtual areas within a single islanded microgrid at the scheduled value by coordinating the outputs of wind power generation and BESS through virtual inertial response, frequency droop control and load frequency control.