Abstract: A method for analyzing quality of electrical energy in a three-phase electric network, the method including: measuring a set of electrical magnitudes, the set including one electrical magnitude per phase; forming a space vector from an instantaneous three-dimensional transformation of the set of measured electrical magnitudes; and determining a set including at least one parameter representative of the quality of the electrical energy in the three-phase electric network, according to the space vector.

Abstract: A method and apparatus to dynamically and adaptively demodulate induction motor instantaneous rotor slot harmonic frequency for line-connected squirrel-cage polyphase induction motors. The instantaneous rotor slot harmonic frequency carries essential information on the instantaneous rotor speed. Based on a correlation between the motor's input power and its rotor slot harmonic frequency, a dynamically varying carrier frequency is computed and used in a rotor slot harmonic frequency detector. The rotor slot harmonic frequency detector is based on a superheterodyne principle. It contains a generalized linear-phase low-pass filter, whose bandwidth is estimated dynamically by a filter bandwidth estimator. The rotor slot harmonic frequency detector also includes a latency compensator, which receives the dynamically varying carrier frequency signal and synchronizes it with the output of a frequency demodulator.

Abstract: A method for analyzing quality of electrical energy in a three-phase electric network, the method including: measuring a set of electrical magnitudes, the set including one electrical magnitude per phase; forming a space vector from an instantaneous three-dimensional transformation of the set of measured electrical magnitudes; and determining a set including at least one parameter representative of the quality of the electrical energy in the three-phase electric network, according to the space vector.

Abstract: A method and apparatus to dynamically and adaptively demodulate induction motor instantaneous rotor slot harmonic frequency for line-connected squirrel-cage polyphase induction motors. The instantaneous rotor slot harmonic frequency carries essential information on the instantaneous rotor speed. Based on a correlation between the motor's input power and its rotor slot harmonic frequency, a dynamically varying carrier frequency is computed and used in a rotor slot harmonic frequency detector. The rotor slot harmonic frequency detector is based on a superheterodyne principle. It contains a generalized linear-phase low-pass filter, whose bandwidth is estimated dynamically by a filter bandwidth estimator. The rotor slot harmonic frequency detector also includes a latency compensator, which receives the dynamically varying carrier frequency signal and synchronizes it with the output of a frequency demodulator.

Abstract: An electrical short-circuit detection device includes a first signal processing module for receiving a signal representative of an electrical current and supplying a first signal representative of the value of the electrical current and a second signal representative of the differential of the electrical current, and a second processing module for receiving the signals and comprising a short-circuit detection module for supplying a detection signal according to a curve overshoot. The second processing module monitors a limit curve overshoot and a ratio between variations of the signals. A short-circuit detection signal is supplied when the ratio exceeds a preset threshold. A circuit breaker incorporates such a device. The process comprises monitoring limit curve overshoot and the ratio between variations of the signals.

Abstract: The device comprises modelling means representative of an inverse model of the current transformer. These modelling means receive on input the instantaneous values of the secondary current measured in a first secondary winding of the current transformer and, by means of an integrator, the integral of the secondary voltage measured at the terminals of a secondary winding of the current transformer. The modelling means supply on output the instantaneous values of the associated primary current, corrected in case of saturation of the transformer. The secondary voltage can be supplied by the first secondary winding or by an additional second secondary winding, arranged around the first one.

Abstract: The electrical short-circuit detection device comprises first signal processing means receiving a signal representative of an electrical current and supplying a first signal representative of the value of said electrical current and a second signal representative of the differential of said electrical current, and second processing means receiving said signals and comprising short-circuit detection means supplying a detection signal according to a curve overshoot. The second processing means monitor a limit curve overshoot and a ratio between variations of said signals. A short-circuit detection signal is supplied if said ratio exceeds a preset threshold. The circuit breaker incorporates such a device. The process comprises monitoring steps of limit curve overshoot and of the ratio between variations of the signals.

Abstract: The device comprises modelling means representative of an inverse model of the current transformer. These modelling means receive on input the instantaneous values of the secondary current measured in a first secondary winding of the current transformer and, by means of an integrator, the integral of the secondary voltage measured at the terminals of a secondary winding of the current transformer. The modelling means supply on output the instantaneous values of the associated primary current, corrected in case of saturation of the transformer. The secondary voltage can be supplied by the first secondary winding or by an additional second secondary winding, arranged around the first one.