Abstract
A wideband series harmonicvoltage compensator (WSHVC) for mitigating the adverse effect of unknown grid impedance and load condition on the stability of microgrids with multiple grid-connected inverters (GCIs) is presented. The concept is based on extending the concept of series active power filter. A wideband series voltage source inverter is used to compensate for the high-frequency harmonic voltage caused by the impedance at the point of common coupling, thereby creating a virtually zero high-frequency impedance at the output of the GCIs. The system stability is then assured under any operating condition. The bandwidth of the WSHVC ranges from the second harmonic of the grid frequency to 8 kHz, which is sufficiently higher than the cut-off frequency of typical GCIs. Such fast dynamic behavior is realized by a novel fixed-frequency predictive control scheme with nonlinear switching surfaces. Since the WSHVC handles harmonic power only, its volt-ampere rating is lower than that of the entire system. A 500 VA prototype for a 6.5 kVA testbed with three commercial GCIs, nonlinear load, and adjustable grid impedance has been evaluated. The power dissipation of the WSHVC is less than 1% of the VA rating of the testbed. The effectiveness of the WSHVC on improving system stability is studied.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.