Exploiting DOD set value to manage the operation of a diesel generator in a hybrid renewable system

In off-grid mode operation, electricity supplied by photovoltaic panels and batteries are not usually efficient to meet the load power demand at any time. Thus, a diesel generator (DG) source is necessary as a backup in order to cover the load needs at any time. However, the diesel generator requires a time to reach its steady state operation. Thus, turning ON the diesel generator must not wait the depth of discharge (DOD) of batteries to reach the max set value because this will cause a blackout. A management scheme is proposed here to control the time at which the DG is turned ON to avoid black out and to minimize pollution and diesel consumption costs. The proposed method is based on predicting the load every two minutes using auto-regressive moving average (ARMA) scheme associated with a Kalman Filter. Then, an optimal DOD value is found for each load required power at which the DG must turned ON before reaching a max DOD value of 80%. This management scheme exploit better the power available in the hybrid renewable system and minimize the pollution and cost of operating the DG. As a result, lower energy lost during operation of the system.