Detection method of three-phase mains supply power failure

Detection method of three-phase mains supply power failure

  • CN 105,301,522 A
  • Filed: 11/23/2015
  • Published: 02/03/2016
  • Est. Priority Date: 11/23/2015
  • Status: Active Application
First Claim
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1. a detection method for three-phase mains power down, is characterized in that, comprises the following steps:

  • Step S1;

    real-time sampling three-phase mains instantaneous voltage Ua, Ub, Uc;

    Step S2;

    the voltage difference Ux calculating the maxima and minima in three-phase mains instantaneous voltage Ua, Ub, Uc in real time;

    Step S3;

    judge whether Ux is less than the voltage threshold Ud of setting, if Ux <

    is Ud, enters step S4, otherwise enter step S5;

    Step S4;

    power down counter Cnt adds 1;

    Step S5;

    power down counter Cnt resets, and returns step S1;

    Step S6;

    judge whether power down counter Cnt is more than or equal to power down count threshold Cmax, Cmax=t*f, if Cnt >

    =Cmax, then judge civil power power down, otherwise return step S1;

    Wherein, f is three-phase mains sample frequency, and 1kHz≤

    f≤

    40kHz, t is detection of power loss filter filtering time, 2ms≤

    t≤

    5ms.

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