Method for small-signal stability assessment of power systems using source side shunt current injection and load side perturbations

摘要

A novel method for real-time small-signal stability analysis for power electronic-based components in a power system. The method may be used to monitor a power system in real-time by perturbing the source side of an electronic-based component of the power system using a shunt current injection of about 0.5 to 1 percent of a nominal current of the power system at the source side, and perturbing the load side of the power electronic-based component by varying the voltage at the load side. Time-domain results of the perturbations may be transferred to frequency-domain results and the stability of the power system may be monitored by obtaining a Nyquist contour and employing Generalized Nyquist Criterion or unit circle criterion.

主权项

1. A method comprising:
providing non-transitory computer readable media as executed by a system controller comprising a specialized chip to perform a method for real-time analysis of small-signal stability of a power system comprising at least one power electronic-based component, the method comprising: observing the power system in a real-time operational mode, the power system comprising a source side and a load side from a perspective of the power electronic-base component; perturbing the source side of the power electronic-based component by injecting a current of about 0.5 to about 1 percent of a nominal current of the power system using shunt current injection at the source side, and perturbing the load side of the power electronic-based component by varying a voltage of the power system, wherein perturbing the source side of the power electronic-based component and perturbing the load side of the power electronic-based component occurs simultaneously; measuring currents and voltages at the source side and at the load side; determining a phase of the power system using single-phase Phase Lock Loop; transforming the measured source side current and voltage and the measured load side current and voltage to a d-q reference frame using the determined phase of the power system; transferring time-domain source side current and voltage values and time-domain load side current and voltage values to frequency-domain current and voltage values using Fourier transforms; calculating a frequency-domain return-ratio matrix in the d-q reference frame using the frequency-domain source side current and voltage values and the frequency-domain load side current and voltage values; plotting a Nyquist contour of a component using the frequency-domain return-ratio matrix; and evaluating small-signal stability of the power system using stability criteria.