Method and the system of the protection of three-phase electric devices symmetrically loaded against the effects of short circuits of single turns of windings

摘要

how is that, during the work device signals from transducers measuring each phase is processed in digital form and measure the initial phases of signals.on the basis of them, sets the value of the angle phase shift between adjacent signals of each pair,and then made comparison values of the phase shift angle of each pair of signals with the signal of a reference value with the previously established for efficient equipment in actual warunkach power. then counts are consecutive in subsequent periods the current exceeding a pre-set value.in the case when the next period no exceedance is counting starts from scratchhowever, when the values of a are in consecutive at least k successive periods of current activates the device.the security system is characterized by the fact that each measurement transducers (pp1, pp2, by pp3), is connected with the corresponding digital / analogue to digital (pac1, pac2, pac3).a transducer (pac1) is combined with entrances measuring blocks (bpl1l2, bpl3l1).a transducer (pac2) is combined with entrances measuring blocks (bpl1l2, bpl3l1) and a transducer (pac3) is combined with entrances measuring blocks (bpl2l3, bpl3l1).each of the blocks (bpl1l2 exit, bpl2l3, bpl3l1) are connected to the corresponding inputs of digital komparatoru00f3w (kz1, kz2, kz3) skalowanych calibration signal to a pre-set value.in addition, the entry komparatoru00f3w (kz1, kz2, kz3) are connected to a memory (pz) of a reference signal, and outputs komparatoru00f3w (kz1, kz2,kz3) are connected with the meter exceedances (lp), whose output is combined with transmitter (wu) initiating a shutdown device.