An arc eliminator includes a housing having a space formed therein and including an opening, an arc extinguishing part installed in the housing and including a moving rod disposed to be movable to the space, an indicator rotatably installed within the housing and seen through the opening, and an indicator rotating mechanism interworking with the moving rod when the moving rod moves, to rotate the indicator. A closing state and opening state of an arc extinguishing part may be easily recognized through an indicator and an arc accident may be minimized.

The present invention provides a distribution board having a main breaker and a plurality of branch breakers, the distribution board being wired to branch power supplied to the main breaker into each branch breaker, the distribution board including: a plurality of noise detection sections configured to correspond to the respective branch breakers one-to-one and each configured to output a detection signal based on a noise component of not less than a predetermined frequency generated on a secondary side of each branch breaker; and processor configured to separately receive the detection signal output from each noise detection section and determine whether the detection signal is high frequency noise at a threshold or more.

The present invention provides a distribution board having a main breaker and a plurality of branch breakers, the distribution board being wired to branch power supplied to the main breaker into each branch breaker, the distribution board including: a plurality of noise detection sections configured to correspond to the respective branch breakers one-to-one and each configured to output a detection signal based on a noise component of not less than a predetermined frequency generated on a secondary side of each branch breaker; and processor configured to separately receive the detection signal output from each noise detection section and determine whether the detection signal is high frequency noise at a threshold or more.

An earthing module for a switchgear includes: a cylinder; a piston; a stored energy unit; and at least one photovoltaic cell. The cylinder connects to a part of a switchgear at earth potential. The piston moves within the cylinder from a standby position to a released position along an axis of the cylinder. When in the released position, the piston is in electrical connection with the cylinder. The stored energy unit is located within or associated with the earthing module such that activation of the stored energy unit moves the piston from the standby position to the released position. One or more of the at least one photovoltaic cell activates the stored energy unit based on radiation from an electrical arc of the switchgear impinging upon the one or more of the at least one photovoltaic cell.

Method and system allowing more accurate detection and identification of unwanted arcing include novel processing of signal voltage representing recovered power-line current. In one implementation, arc-faults are detected based on numerical analysis where individual cycles of line voltage and current are observed and data collected during each cycle is processed to estimate likelihood of presence of arc-event within each individual cycle based on pre-defined number of arc-events occurring within pre-defined number of contiguous cycles. In another implementation, fast transient current spikes detection can be done by: computing difference values between consecutive line-current samples collected over a cycle, average of differences, and peak-to-peak value of line-current; comparing each difference value to average of difference; comparing each difference value to peak-to-peak value; and, based on calculation of composite of two comparisons, using thresholds to determine if arcing is present within processed cycle.

A set of electrical protection devices with two levels that are connected in series, the first level including a circuit breaker that is referred to as the first or upstream circuit breaker and the second level including one or more circuit breakers referred to as second or downstream circuit breakers, which are connected in parallel with respect to one another. The trip for the upstream circuit breaker, instead of including what are referred to as instantaneous protection means, includes, firstly, a first trip chain making it possible to adjust the long-delay trip curve for inverse time and the short-delay trip curve with a no-trip time and, secondly, a second trip chain including an optical sensor that is capable of discerning light between 300 and 450 nm by eliminating visible and infrared light so as to eliminate the light that is characteristic of gas jets emitted by the one or more circuit breakers referred to as downstream circuit breakers during a switching operation, and means for simultaneously measuring the current level and the maximum threshold of light emitted at the busbars, this second trip chain being capable of causing the upstream circuit breaker to trip when the current exceeds a predetermined value and the light emitted exceeds a predetermined threshold for emitted light.

A method for partial discharge recognition in high voltage applications and a high voltage unit using the method, includes the steps of detecting a signal, transforming the signal from time to frequency domain, cutting frequencies above a defined threshold, and retransform the truncated signal from frequency to time domain. The information content of detected and truncated signals is determined and compared.

A method for partial discharge recognition in high voltage applications and a high voltage unit using the method, includes the steps of detecting a signal, transforming the signal from time to frequency domain, cutting frequencies above a defined threshold, and retransform the truncated signal from frequency to time domain. The information content of detected and truncated signals is determined and compared.

A signal sampling circuit for arc detection includes plural current sensors, plural high pass filter circuits, and an adder circuit. Each of the current sensors is configured to sense a measured current and then generate a sensed voltage signal. One of the high pass filter circuits receives the sensed voltage signal from one of the current sensors and performs high-pass filtering on the sensed voltage signal. The adder circuit performs scaling up, adding, and DC offset on the high-pass filtered sensed voltage signals. Each of the high pass filter circuits is composed of a filter capacitor and a first resistor connected in series with the filter capacitor. The adder circuit is composed of the first resistors, a first operational amplifier, and a second resistor.

A sensing arrangement for detection of electrical discharges in an electrical apparatus is described. The sensing arrangement includes an acoustic sensor and a signal enhancing structure with a funnel region. The acoustic sensor is positioned outside the funnel region on an apex side of the funnel region. An electrical switchgear is described. The electrical switchgear includes a sensing arrangement for detection of electrical discharges in an electrical apparatus. The sensing arrangement includes an acoustic sensor and a signal enhancing structure with a funnel region.