METHOD AND APPARATUS FOR DETERMINING A WEAKENED GRID CONDITION AND CONTROLLING A POWER PLANT IN A MANNER APPROPRIATE TO THE GRID CONDITION

摘要

Method and apparatus are provided for determining a grid condition, such as a weakened grid condition, and controlling a power plant, such as a wind or solar power plant, in a manner which is appropriate to the grid condition. The method includes measuring (14) output parameters of a generator, such as a wind turbine or PV generator. The measured output parameters include reactive power and voltage. The method further includes determining (16) a relationship between the measured output parameters of the generator. The relationship between the measured output parameters of the generator is indicative of a condition of a power grid to which the plant supplies power. The method allows controlling (18) the plant responsive to the relationship between the measured output parameters of the generator to avoid onset of oscillatory behavior, which could otherwise occur in the power plant in the presence of a weakened grid condition.