Injection Amplitude Guidance for Impedance Measurement in Power Systems

Impedance measurement techniques based on small-signal injections in ac power system have been well developed but a gap in the analysis is that the selection of an injection amplitude is based only on experience. This letter develops an analytical process to analyze the noise existing in power systems and thereby determines the minimum injection amplitude according to an allowable error. The process is based on knowledge of stochastic processes and statistics, where the Monte Carlo method is also employed to simplify the process. A power hardware-in-the-loop system with a grid-following inverter is employed in experimental verification of the results.

Automated summary

Impedance measurement techniques based on small-signal injections in ac power system have been well developed but lack accurate selection of injection amplitude. This letter proposes an analytical process to analyze power system noise and determine the minimum injection amplitude based on an allowable error. The process utilizes stochastic processes, statistics, and the Monte Carlo method. Experimental verification is performed using a power hardware-in-the-loop system with a grid-following inverter.