The present invention discloses a method for quickly eliminating ferromagnetic resonance of a voltage transformer. The method includes: first sampling a three-phase voltage and an open-delta voltage of a voltage transformer; calculating a flux linkage corresponding to a zero-sequence voltage by means of an integral algorithm; and when detecting that ferromagnetic resonance occurs in the mutual inductor, further checking whether the absolute value of the flux linkage corresponding to the zero-sequence voltage or the absolute value of the open-delta voltage respectively falls within a set range, and if yes, starting a secondary resonance elimination loop for resonance elimination. The present invention also discloses a corresponding device for quickly eliminating ferromagnetic resonance of a voltage transformer. The present method and device accurately analyze and control resonance elimination trigger time based on a conventional secondary resonance elimination principle, and can effectively eliminate the impact of the core saturation of a voltage transformer on a resonance elimination process, thereby greatly improving the success probability of single resonance elimination.

The present invention discloses a parameter tuning approach for bypass damping filter to suppress subsynchronous resonance in power systems, namely determining the parameters of capacitor, inductor and damping resistor in BDF. Using this approach, the parameters of capacitor and inductor in BDF can be adjusted, so that the frequency where the negative electrical damping of generator reaches minimum can be away from the frequency range of low frequency oscillation mode and typical frequencies of each torsional mode; the parameter of damping resistor in BDF can be further adjusted so that the minimum value of negative electrical damping is in reasonable range. The application of BDF with parameters tuned by the present invention contributes to the suppression of both the torsional interaction effect and the transient torque amplification effect.

The disclosed embodiments relate to method and/or device which is effective at cancelling or altering electrical signals or pulses, generated by, for example, digital electronic systems and components, that are induced, reflected or otherwise made present on the mains power supply conductors and/or the earthing or grounding conductor (if present.) The disclosed embodiments cancel these electrical signals thereby providing an effective means of preventing the exfiltration of various data from a computing or similar system by means of power line emissions. The disclosed embodiments may perform this subjugation by: altering the shape of the fundamental current and voltage waveforms and also altering and diminishing any non-fundamental frequency waveforms to a point where they are no longer measurable or detectable; and preventing the communication via inductive coupling of any electrical signals on mains current onto the grounding path or vice versa.

A surge blocking inductor. In one embodiment, the surge blocking inductor includes a core; a first winding wound about the core in a first direction; and a second winding wound about the core in a second direction, wherein the first winding and the second winding are magnetically independent when the core is in a non-saturated state, and wherein the first winding and the second winding are coupled magnetically when the core is in a saturated state.

An electrical damping device comprises a positive path that comprises a first resistive-inductive (RL) network in parallel with a second RL network, wherein the positive path is coupled between the positive terminals of the DC ports. A negative path comprises a third RL network in parallel with a fourth RL network, wherein the negative path is coupled between the negative terminals of the DC ports. A first transformer is defined by a first inductance of first RL network and a third inductance of the third RL network, wherein the first transformer comprises windings arranged for mutual coupling between the positive path and the negative path. A second transformer is defined by a second inductance of the second RL network and a fourth inductance of the fourth RL network, wherein the second transformer comprises windings arranged for mutual coupling between the positive path and the negative path.

The disclosed embodiments relate to method and/or device which is effective at cancelling or altering electrical signals or pulses, generated by, for example, digital electronic systems and components, that are induced, reflected or otherwise made present on the mains power supply conductors and/or the earthing or grounding conductor (if present.) The disclosed embodiments cancel these electrical signals thereby providing an effective means of preventing the exfiltration of various data from a computing or similar system by means of power line emissions. The disclosed embodiments may perform this subjugation by: altering the shape of the fundamental current and voltage waveforms and also altering and diminishing any non-fundamental frequency waveforms to a point where they are no longer measurable or detectable; and preventing the communication via inductive coupling of any electrical signals on mains current onto the grounding path or vice versa.