Automatic reactive power compensation of an isolated wind-diesel hybrid grid

The paper presents the study of reactive power control for an isolated wind-diesel hybrid grid model. The permanent-magnet synchronous generator (PMSG) is used with diesel engine set and permanent-magnet induction generator (PMIG) for wind power generation. Considering frequency is being maintained within limits by the diesel engine generator set, the AC to DC to AC converter is not required with PMSG. A mathematical approximation model for the injection of reactive power by PMSG connected with diesel engine set is developed in this paper. To maintain the voltage of the system at desired level within limits, a controlled source of reactive power is required. In this paper, the static synchronous compensator (STATCOM) is used as a reactive power compensator. Integral square error (ISE) criterion is used to obtain the optimum gain settings of the STATCOM proportional and integral (PI) controller. The dynamic responses of the system for small disturbance conditions are shown in the paper. The paper also shows the comparison of the performance of the system when synchronous generator (SG) is used instead of PMSG with diesel engine set.