Multifunctional Control Strategy to Prevent Microgrid Blackout

A multifunctional control approach is adopted in this work to avoid the microgrid power failure that is a result of subsequent failure of the renewable operating units and utility grid. A microgrid consisting of more than two renewable resources and utility grid is prone to generation failure due to intermittent renewable resources. So, an energy storage is introduced to serve the purpose of feeding the critical loads. However, a situation can persist when the battery is discharged and the demand of the consumers is not fulfilled. For such cases, the diesel generator (DG) is brought into action so that instances of generation shortage from renewable resources and completely drained battery storage are complemented. The seamless operating modes namely current control and voltage control are enabled in accordance to the availability of the utility grid. On the existence/recovery of the faults, the static transfer switches (STS) isolate/reconnect the microgrid to the utility. The functional attributes of the microgrid include, elimination of the harmonics, balancing of the DG currents, maximum power point extraction from solar and wind. The output of the DG is controlled by the automatic voltage regulator (AVR) associated at the synchronous generator (SG) field terminals. The microgrid is modelled in MATLAB and the microgrid conduct under the practical operating conditions, is observed in detail. The microgrid allows sensitive load operation, uninterrupted residential load supply and improved power quality.