System and method for impedance measurement using series and shunt injection

摘要

A method for impedance measurement in a three-phase AC system is provided. The method includes injecting a shunt perturbation signal into the three-phase AC system and collecting a response to the shunt perturbation signal, and injecting a series perturbation signal into the three-phase AC system and collecting a response to the series perturbation signal. The response to the shunt perturbation signal and the response to the series perturbation signal are then transferred from abc coordinate to dq coordinates. At least one impedance of the three-phase AC system is calculated based on the response to the shunt perturbation signal and the response to the series perturbation signal.

主权项

1. A method of impedance measurement in a three-phase alternating current (AC) system, the method comprising:
connecting a perturbation injector to the three-phase AC system, the perturbation injector comprising a voltage source inverter having a shunt injection circuit and a series injection circuit that are operable without active DC power addition; connecting by the perturbation injector the shunt injection circuit to the three-phase AC system; injecting by the shunt injection circuit a shunt perturbation signal into the three-phase AC system; collecting by a collection circuit of an impedance measurement unit a response to the shunt perturbation signal; switching by the perturbation injector from the shunt injection circuit to the series injection circuit; injecting by the series injection circuit a series perturbation signal into the three-phase AC system; collecting by the collection circuit of the impedance measurement unit a response to the series perturbation signal; transferring by an instrumentation platform computer the response to the shunt perturbation signal and the response to the series perturbation signal from three-phase (abc) coordinates to direct and quadrature (dq); and calculating by a control circuit at least one impedance of the three-phase AC system based on the response to the shunt perturbation signal and the response to the series perturbation signal.