A method for estimating grid properties of a power grid coupled to a generator at a point of common coupling is provided. First, a voltage VPCC at the point of common coupling is measured. Second, a current IPCC at the point of common coupling is measured. Third, the grid properties are estimated by a grid model using as input parameters the measured voltage VPCC at the point of common coupling, the measured current IPCC at the point of common coupling and the determined phase angle. Advantageously, the absolute phases of the voltage and the current at the point of common coupling are not necessary, which makes the present method less prone to errors due to measurement noise. Further, a device and a computer program product are provided.