A power control system for a generator includes a control unit, an input sensing unit, an output sensing unit, and a power conversion unit. The input sensing unit senses a voltage and a current, generated from the generator. The output sensing unit senses a load voltage and a load current, received by the load. The power conversion unit receives the voltage and the current, and converts the voltage and the current into the load voltage and the load current. The control unit judges and predicts the mechanical behavior of the generator to control the generator according to the received voltage, the current, the load voltage, and the load current.