System and Method for Impedance Measurement Using Series and Shunt Injection

The invention is system architecture and its implementation used to measure impedances online in balanced three-phase systems. The impedance is a useful tool in the work related to small signal system stability. It is beneficial to both system integrators and component vendors. The extracted impedances of system components can be used to assess the system stability before system integration. The impedances measured in system can also be used to debug exisitng system stability problems. Impedance measurement takes several steps: creating perturbation in the system, measurement system response, and calculating system impedances. This invention describes system architecutre of such a measurement system. The system uses both shunt and series injection methods to achieve accurate measurement of both source and load side. The perturbation is created by a power-electronics converter. The system responses are measured by the sensors and then digitized. The digitized signals are then processed both in real time and later in a host computer to calculate the system impedance. The system design is suitable for measurement in systems with power ranges from low power of few kilo-watts to medium power range of few mega-watts.
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For Information, Contact:
Li Chen
Licensing Associate
Virginia Tech Intellectual Properties, Inc.
(540) 443-9217
Zhiyu Shen
Marko Jaksic
Paolo Mattavelli
Dushan Boroyevich
Jacob Verhulst
Mohamed Belkhayat