G01R31/1227

Online and offline partial discharge detection for electrical drive systems

Aspects of the present disclosure are directed to systems and methods for detecting Partial Discharge (PD) associated with wide bandgap semiconductor-based electrical drive systems in real time. In one aspect, signals, including noise associated with drive switching and other background noises are detected using a sensing device. The signals are received by a real-time spectrum analyzer. The spectrum analyzer transforms the signals into the frequency domain and determines or registers the frequency domain profiles of the signals. The spectrum analyzer performs signal discrimination between at least one other signal included within the signals and switching noise based on their frequency domain profiles. Based on the discrimination analysis, the presence of a partial discharge signal may be detected. A physics-based signal discrimination approach can also be used for signal discrimination, for example utilizing pressure-dependency of characteristics of a PD signal.

Method for detecting and transmitting dormant failure information
11005258 · 2021-05-11 · ·

An electrical equipment includes a first load configured for a nominal use of the equipment, at least one first metal screen, a sensor configured to measure a quantity characteristic of the first load, and a power supply conductor, wherein the first load and the at least first metal screen are linked electrically to the power supply conductor, and in that the equipment also comprises a comparator configured to compare measurements from the sensor to detect a dormant failure of the at least first metal screen.

PARTIAL DISCHARGE SENSOR

An approach to detecting partial discharge events involves retrofitting an electrical system to include a capacitive sensor configured to capacitively sense partial discharge events of a component of the electrical system. The capacitive sensor has a first electrical conductor that forms a first terminal of the capacitive sensor, a second electrical conductor that forms a second terminal of the capacitive sensor, and a dielectric that separates the first electrical conductor and the second electrical conductor. The capacitive sensor generates an electrical sensor signal at an output of the capacitive sensor in response to the partial discharge event. The electrical sensor signal is converted to an optical signal and the optical signal is processed to detect an occurrence of the partial discharge event.

DC arc detection and photovoltaic plant profiling system

An arc detection method includes classifying whether an arc fault is present in the power system by, for each of a plurality of bins of a current frame of a signal, marking the bin as a candidate bin if a magnitude spectrum of the bin meets first criteria; determining a number of candidate bins in the current frame; marking the number of candidate bins as candidate cluster bins if the number of candidate bins exceeds a minimum cluster size; for each of the candidate cluster bins, determining whether the candidate cluster bin is also a candidate cluster bin of a previous frame of the first signal and if so, identifying the current frame as a candidate frame and incrementing a candidate frame count; and if the candidate frame count exceeds a candidate frame count threshold, determining that an arc fault is present in the power system.

MONITORING DEVICE FOR EMERGENCY STANDBY OPERATION

To determine an AC insulation resistance between the AC connections of an inverter and a ground potential, the AC connections are connected to an AC energy sink in an emergency standby operation in order to transmit energy from a DC energy source to an AC energy sink and an insulation test is performed in emergency standby operation. An AC fault current flowing between an AC connection and the ground potential is determined, and the AC insulation resistance is calculated from the AC fault current.

Arc detection and prevention in a power generation system

A method for arc detection in a system including a photovoltaic panel and a load connectible to the photovoltaic panel with a DC power line. The method measures power delivered to the load thereby producing a first measurement result of the power delivered to the load. Power produced by the photovoltaic panel is also measured, thereby producing a second measurement result of power produced by the photovoltaic panel. The first measurement result is compared with the second measurement result thereby producing a differential power measurement result. Upon the differential power measurement result being more than a threshold value, an alarm condition may also be set. The second measurement result may be modulated and transmitted over the DC power line.

SYSTEM AND METHOD OF DETERMINING AGE OF A TRANSFORMER
20210063496 · 2021-03-04 ·

A method of determining polymerisation of transformer insulation within a transformer. The method includes the steps of measuring a first and second moisture activity of oil in a transformer, and a first and second temperature of the transformer. The method further includes calculating the ratio of the gradients of the moisture equilibrium curves associated with the moisture activity and the temperature. The calculated ratio can then be used to characterise the polymerisation of the insulation and age of the transformer.

POWER CONVERSION DEVICE, ROTATING MACHINE SYSTEM USING SAME, AND DIAGNOSIS METHOD FOR SAME
20210072319 · 2021-03-11 ·

A power conversion device according to the present invention is connected to a rotating machine comprising an armature coil and supplies and receives power. The power conversion device has a function for: collectively applying voltage pulses to the armature coil or coils for one or more specific phases of the rotating machine, sampling the current values of the specific phases from the start of the rising or falling of the voltage pulses until a designated delay time, detecting variation in the capacitance of an insulation member of the armature coils of the specific phases of the rotating machine from variation from a normal state of the current values, and diagnosing insulation degradation.

SYSTEM FOR MONITORING FOR PARTIAL DISCHARGES IN AN ITEM OF ELECTRICAL EQUIPMENT VIA GASEOUS EMISSIONS

Method for monitoring for partial discharges in an electrical installation comprising at least one electrical cubicle, the electrical cubicle comprising at least one item of medium-voltage or high-voltage electrical equipment.

APPARATUS AND METHOD FOR ANALYZING CAUSE OF FAILURE DUE TO DIELECTRIC BREAKDOWN ON BASIS OF BIG DATA
20210063459 · 2021-03-04 ·

An apparatus and a method for analyzing a cause of a failure due to a dielectric breakdown based on big data are provided. A failure cause factor data set, a normal state data set, or a state recovery data set is generated and transmitted to a big data server when a dielectric resistance value is measured to be a minimum normal value or less. A cause of a failure is analyzed by receiving data corresponding to the data sets from the big data server, calculating influence indexes for failure cause factors, and selecting a failure cause factor based on the basis of the influence indexes.