This paper proposes a novel virtual impedance method for uninterruptible power system (UPS) inverters with parallel connected capability. To achieve wireless control, the droop control method is adopted. However, the power sharing accuracy is highly sensitive to the output impedance of inverter. So, a virtual output impedance is usually added to alleviate the unbalance of output impedance between each inverter and then, improve power sharing accuracy. The virtual impedance is implemented as the time derivative of the inverter output current, the differential progress will amplify the noise presented in output current, result in high sensitivity to the noise for the virtual impedance. To solve this problem, a novel virtual impedance by combining with a low-pass filter is proposed, which not only balances the output impedance of inverter, but also achieves better output voltage THD when sharing nonlinear loads. The double loop control method for inverter provids a good tracking of output voltage reference and high quality output waveform. Simulation results are presented from a parallel connected UPS system to validate this method.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    A novel virtual impedance method for droop controlled parallel UPS inverters with wireless control


    Contributors:
    Lu Jiaxin (author) / Zhang Yingchao (author) / Qian Xisen (author) / Long Jiangtao (author) / Zhao Zhengming (author)


    Publication date :

    2014-08-01


    Size :

    704942 byte




    Type of media :

    Conference paper


    Type of material :

    Electronic Resource


    Language :

    English



    Virtual impedance attenuation based control of parallel inverters

    Ningning Li / Xisheng Tang / Xiaofeng Zhang et al. | IEEE | 2014


    Local frequency restoration for droop-controlled parallel inverters in islanded microgrids

    Rey López, Juan Manuel / Rosero Chandi, Carlos Xavier / Velasco García, Manel et al. | BASE | 2018

    Free access


    Robust Stabilization of Parallel Inverters-Based Microgrid: Droop Control Strategy

    Alfergani, Asma / Buaossa, Nagi / Tahir, Ahmed et al. | IEEE | 2021


    Sliding mode based droop control strategies for parallel-connected inverters in railway vehicles

    Buzzi, A. C. / Incremona, G. P. / Colaneri, P. et al. | BASE | 2020

    Free access