4results about "Frequency selective voltage/current level measurement" patented technology

System for diagnosing a battery cell (204) of a vehicle (100), comprising: a processor (302) and a working memory (304) or data storage (308) comprising an algorithm or computer instructions which, when executed by the processor (302), perform an operation comprising: Determine that a current flows through a current collector (206, 214) of the accumulator cell (204), Generating a mechanical excitation of the current collector (206, 214), Determining the amplitude of a voltage across the accumulator cell (204) based on mechanical excitation, and Determining the presence of a crack or separation of a foil of the current collector (206, 214) on the basis of the amplitude of the voltage across the accumulator cell (204).

The present invention relates to the field of power systems and automation, and discloses a method and system for identifying discharge hazards of transmission lines. The method comprises: acquiring and processing measured data of discharge hazards of the transmission lines, high-frequency discharge waveform data, and acquiring and discharge event data; creating a hazard identification requirement table and initializing same, and updating all elements in the table in the time sequence; looking up, for each newly acquired waveform segment, table to determine the operation and maintenance requirement, and performing comprehensive early warning on the hazard state of the lines.

A current transformer includes a current sensor sensing a current of a conductor signal transmitted along a conductor and outputting a current signal based on the current and an electronic assembly connected to the current sensor and receiving the current signal from the current sensor. The electronic assembly determines an operating state of a powered device to which the conductor feeds the conductor signal based on the current signal. The electronic assembly is tuned to use the current signal of the current in a frequency range greater than or equal to 100 Hz to determine the operating state.

The application provides an IGBT hard switching loss current sensor-free measurement method suitable for an INPC topology, a commutation process of an IGBT in the INPC topology is analyzed systematically from the physical mechanism of a hard switching process of a power device, and the switching characteristics of the IGBT are mainly studied. On this basis, the mapping relationship between the voltage waveform characteristics and the current change and the switching loss is determined, and a corresponding hard switching loss analytical model is established. The model established in the application only depends on the parameters of the device data book and the measured collector-emitter voltage data, does not need to introduce a current sensor or an additional test structure in the main power loop, and can realize effective evaluation of the IGBT hard switching loss in the INPC topology. The measurement method has lower requirements for test conditions and has good engineering applicability, and the accuracy is verified by simulation results.