Online grid impedance measurement using discrete-interval binary sequence injection
- 1 June 2013
- conference paper
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
Abstract
Grid impedance affects the stability and control performance of grid-connected power electronic devices such as inverters used to integrate wind and solar energy. Adaptive control of such inverters to guarantee stability under different grid conditions requires real-time measurement of the grid impedance performed online by the inverters themselves. Existing online measurement methods based on broadband excitations such as maximum-length binary sequence (MLBS) require relatively high injection that may interfere with normal grid control functions, or degrade inverter output current quality, especially when the grid impedance is low and a high current needs to be injected in order to produce sufficient voltage perturbation. This paper proposes the use of a discrete-interval binary sequence (DIBS) for such cases. The DIBS is a computer-optimized binary sequence where the energy is maximized at specified harmonic frequencies to minimize the required level of signal injection. Experimental results based on a three-phase grid-connected inverter are presented to demonstrate the effectiveness of the proposed methods.Keywords
This publication has 15 references indexed in Scilit:
- Broadband methods for online grid impedance measurementPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2013
- Impedance-Based Stability Criterion for Grid-Connected InvertersIEEE Transactions on Power Electronics, 2011
- A study of renewable energy system harmonic resonance based on a DG test-bedPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2011
- New Techniques for Measuring Impedance Characteristics of Three-Phase AC Power SystemsIEEE Transactions on Power Electronics, 2009
- Grid Impedance Estimation via Excitation of $LCL$-Filter ResonanceIEEE Transactions on Industry Applications, 2007
- Design and application of multifrequency signalsComputing & Control Engineering Journal, 1991
- On-Line Identification of Process Dynamics: Use of Multifrequency Binary SequencesIndustrial & Engineering Chemistry Process Design and Development, 1980
- Synthesis of discrete-interval binary signals with specified Fourier amplitude spectraInternational Journal of Control, 1979
- Binary Multifrequency Signals - Synthesis and ApplicationIFAC Proceedings Volumes, 1979
- Optimum Binary Signals for Reactor Frequency Response MeasurementsNuclear Science and Engineering, 1972