Loading patent…
AssigneeBBC Brown, Boveri & Company, Limited
InventorsOtto Lanz, Jiri Mastner, Michael Vitins
Estimating the term…
A method of and apparatus for the detection of short-circuits on lines operated with voltages and currents containing an alternating component, by detecting the temporal progression of the voltage and current at a measurement location in the form of measurement voltages and measurement currents. From the measurement voltage and measurement current or from magnitudes derived therefrom there are formed traveling wave signals of the form: a(t) = k. (u.sub.m + R.sub.w.i.sub.m) and b(t) = k. (-u.sub.m + R.sub.w.i.sub.m) wherein u.sub.m represents the measurement voltage and i.sub.m the measurement current or magnitudes derived therefrom, R.sub.w an impedance factor and k a freely introducable proportionality factor. There is monitored the mutual phase position of at least one respective frequency component of the oppositely moving traveling wave signals as a magnitude characterizing the condition of the line.
A method for the detection of short-circuits on lines, which are operated with voltages and currents containing an alternating component, by detecting the course as a function of time of the voltage and current at a measurement location in the form of measurement voltages and measurement currents, the improvement comprising the steps of:
An apparatus for the detection of short-circuits on a line, operated with voltages and currents containing an alternating component, by detecting the course as a function of time of the voltage and current at a measurement location in the form of measurement voltages and measurement currents, said apparatus comprising a voltage measurement device for detecting the measurement voltage, a current measurement device for detecting the measurement current, a measurement voltage channel connected in circuit with the voltage measurement device, a measurement current channel connected in circuit with said current measurement device, said measurement current channel including a constant factor multiplier, an addition circuit having input means and output means, a subtraction circuit having input means and output means, said measurement voltage channel and said measurement current channel being connected in parallel with the respective input means of said addition circuit and said subtraction circuit, a phase angle detector, said output means of both said addition circuit and said subtraction circuit being connected with said phase angle detector.
Dependencies are inferred from the claim text.