This paper focuses on three commonly used sensorless methods based on high-frequency signal injection; namely, the rotating sinusoidal injection in the stationary reference frame, the pulsating sinusoidal injection in the estimated synchronous reference frame, and the pulsating square wave injection in the estimated synchronous reference frame. Although these methods have found applications in ...

Grid impedance estimation is used in many power system applications such as grid connected renewable energy systems and power quality analysis of smart grids. The grid impedance estimation techniques based on signal injection uses Ohm’s law for the estimation. In these methods, one or several signal(s) is (are) injected to Point of Common Coupling (PCC). Then the current through and voltage of ...

In this paper, a signal processing method is proposed to estimate the low and high-frequency impedances of power systems using several short-term low power signal injections for a frequency range of 0-150 kHz. This frequency range is very important, and thusso it is considered in the analysis of power quality issues of smart grids. The impedance estimation is used in many power system applicati...