A reactive power control system is provided. The reactive power control system computes a required value for a reactive power based on a state observer method for at least one electrical element in an electrical system. The reactive power control system also generates a reactive power command based on the required value of the reactive power. The reactive power control system further transmits the reactive power command to the electrical element in the electrical system for generating the required value of reactive power to compensate for a voltage change induced by the respective electrical element in the electrical system.