| Citation:Jiexiang Han,Xiangping Kong,Peng Li,Zhe Zhang,Xianggen Yin.A novel low voltage ride through strategyfor cascaded power electronic transformer[J].Protection and Control of Modern Power Systems,2019,V4(3):227-238[Copy] |
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| Abstract: |
| In view of the operating characteristics for voltage sags of AC side of the power electronic transformer(PET), a lowvoltage
ride through(LVRT) strategy adapted to bidirectional power exchange of PET is proposed for the purposes
of maintaining the system stability, assisting the system voltage recovery and protecting PET safety. During
the asymmetric voltage sag, the negative sequence current of PET is eliminated to ensure the symmetry of
the injected current. According to the degree of positive sequence voltage sag, the reactive current injection
is provided to assist in voltage recovery. According to the PET active power condition before the voltage sag,
the level and direction of which are maintained as far as possible without exceeding the limit, for which the
disturbance to the AC and DC grids is reduced. Finally, the effectiveness of the proposed LVRT strategy is
verified by simulation model. |
| Key words: Power electronic transformer, Low-voltage ride through, Control strategy, Current instruction value |
| DOI：10.1186/s41601-019-0137-1 |
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| Fund: |
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