The RTDS® Simulator’s  harmonic scan capability provides an injected harmonic signal into the network during the simulation. Harmonic waveforms of a frequency range specified by the user (up to 9 kHz and with a constant, specified interval) are superposed and applied to the system. The impedance response of the system in the frequency domain is then calculated by the component.

In the RunTime module, a script can be used to perform loop control of injected frequencies and to write the impedance response to an output file. Output can be in the DQ0 or modified PN0 domain, the latter having application in systems with a high penetration of power electronic converters.

Future additions to this component will include a module for conveniently creating Bode plots and determining Nyquist stability criterion for the system based on calculated eigenvalues of the impedance data. Built-in harmonic scanning and stability analysis allows RTDS Simulator users to better intuit the vulnerabilities in their power system.