7199results about "Short-circuit testing" patented technology

Method and apparatus for providing a leak detection circuit for data monitoring and management system using the guard trace of a glucose sensor by applying a leak detection test signal to determine whether a leakage current is present is provided. The leak detection circuit may includes an interface circuit such as a capacitor coupled to the guard trace to detect the leakage current when the leak detection test signal is applied to the guard trace, such that the user or patient using the data monitoring and management system such as glucose monitoring systems may be promptly and accurately notified of a failed sensor, and to alert the user to replace the sensor.

A programmable power (PPSE) switching element including a front power transistor, a main switching transistor, and at least one reverse current blocking transistor in series, a gate of each of which is connected to a gate driver; an inductor and a shunt resistor connected in series with the transistors; a charge storage capacitor connected between ground and a junction located between the inductor and the shunt resistor; a high-speed NPN transistor, a collector of which is connected to the front power transistor and an emitter of which is connected to an output of the main switching transistor via the shunt resistor; a current measurement element in parallel to the shunt resistor; a voltage amplifier; and a high-speed MCU.

A ground fault detector and interrupter for a photovoltaic (PV) energy conversion system, method and apparatus are disclosed. In an exemplary embodiment, the system includes first and second inputs adapted to couple to a first and second rails of a PV array. An inverter is configured to convert DC power generated from the PV array to AC power. A ground fault detector and interrupter, which is coupled to the first and second rails and to the inverter, is configured to detect ground fault conditions in the PV array and to decouple the PV array from the remaining portion of the PV energy conversion system upon such detection. A known signal is coupled to the input of the ground fault detector and interrupter, and then sensed at the output of the ground fault detector and interrupter to determine whether components of the ground fault detector and interrupter are operating properly.

A system and method of monitoring a plurality of electrical assets comprise an electricity distribution infrastructure, including a plurality of electrical asset sensors coupled to the electrical assets for monitoring an operating condition of the electrical assets as well as any fault conditions. The sensors may include a current transformer for obtaining a current waveform, a GPS receiver for applying a synchronized time-stamp to the waveform data, and a mesh network radio for transmitting the time-stamped waveform data. Data from the plurality of sensors may be encrypted and transmitted over a mesh network to one or more gateways that are in communication with a central command processor. In response to an abnormal operating condition of any electrical asset, the central command processor may determine a probable fault location, a probable fault type, and a fault response.

An apparatus for testing the life of a leakage current protection device having a leakage current detection circuit. In one embodiment, the apparatus a trip mechanism state generator, a fault alarm generator, a ground fault simulation unit. In operation, the ground fault simulation unit generates a simulated ground fault signal during every positive half-wave of an AC power, the simulated ground fault signal is detected by the leakage current detection circuit, the leakage current detection circuit responsively generates a signal to turn a switching device into its conductive state so as to allow a current to pass therethrough, the passed current is converted into a DC voltage in accordance with a trip mechanism state generated by the trip mechanism state generator, the fault alarm circuit receives and analyzes the DC voltage and indicates whether a fault exists in the leakage current protection device.

A method and apparatus for testing electromagnetic connectivity in a drill string are disclosed. The method includes transmitting a test signal down a transmission path in a drill string; receiving a reflection of the test signal; and determining from the reflection whether there is an interruption in the electromagnetic connectivity in the transmission path. In general, the apparatus includes a signal generator for generating a test signal into the drill string; a receiver for receiving the reflection of the test signal; and means for determining from the reflection whether there is an interruption in the electromagnetic connectivity in the transmission path. Preferably, a common coil is included through which the test signal generated by the signal generator may be transmitted into a drill string and through which a reflection of the test signal may be received.

A method of measuring the transistor leakage current. In one embodiment, the method involves driving a ring oscillator with a dynamic node driver having a leakage test device biased to an off state to produce a test signal. The test signal is extracted and the frequency is measured. The leakage current is estimated from the measured frequency.

The present invention is directed to an electrical device configured to be disposed in an electrical distribution system between a source of electrical power and an electrical load. The electrical distribution system includes at least one line hot conductor, a line neutral conductor, and a line ground conductor. The line neutral conductor is connected to the line ground conductor at a termination point in the electrical distribution system. The electrical load includes at least one load hot conductor, a load neutral conductor, and a load ground conductor. The device includes a grounding confirmation circuit that includes at least one signal generator that directs at least one test signal into a current path that includes at least the line ground conductor. The grounding confirmation circuit is configured to determine a ground continuity status of the current path based on at least one ground continuity measurement. The circuit interrupter is prevented from entering the reset state if the at least one ground continuity measurement does not meet a predefined quality threshold. The at least one ground continuity measurement being a function of the at least one electrical load parameter after the circuit interrupter is in the reset state.

A method and apparatus for indicating a disconnection within a Distributed Generator (DG). In one embodiment, the apparatus comprises an alarm module electrically coupled to a conductive portion of a component within the DG, wherein the conductive portion is grounded via a ground rod system, and wherein the alarm module (i) is further coupled to a ground line, (ii) couples a monitoring current to the conductive portion, (iii) monitors flow of the monitoring current to determine a change in the flow, and (iv) generates, as a result of the change in the flow, a notification of the disconnection.

A current collecting box for photovoltaic power generation comprising a ground fault detector detecting a ground fault in photovoltaic strings; a switch disposed for each of the photovoltaic strings and interposed between the photovoltaic string and a connecting cable; a control circuit determining the presence of a ground fault and providing an on / off control of the switch; and a power supply supplying the current to the grand fault detector, and the power supply is supplied from a power supply so that the operation check for the ground fault detector is performed based on an output from the ground fault detector. The current supply is supplied and the operation check for an auxiliary switch operating according to an on / off operation of a main switch is performed so that the operation check for a switch is performed.

System for monitoring an electrical system of a facility includes one or more local sensing devices, each of which is adapted to be connected to the electrical system of the facility in proximity to a respective load that receives power from the electrical system so as to make local measurements of a voltage across the load continuity measurements of electrical-power presence at one or more points in the electrical system of said facility. A processing unit is adapted to receive and compare the local measurements to reference measurements of the voltage supplied to the facility, in order to detect a fault in the electrical system.

A method and system for detecting and locating a single-phase ground fault on a low current grounded power-distribution network, comprising: respectively testing and picking up the voltage signals and current signals at multiple positions on each phase feeder (61), and determining the corresponding transient voltage signals and transient current signals according to the extraction of the voltage signals and the current signals (62); when the change in the transient voltage signals and the transient current signals exceeds a preset threshold (63), synchronously picking up the voltage signals and current signals at multiple positions on a three-phase feeder (64); calculating corresponding zero-sequence voltages and zero-sequence currents according to the voltage signals and current signals synchronously picked up at multiple positions on the three-phase feeder (65), and then extracting the steady-state signal and transient signal of the zero-sequence voltage and zero-sequence current at each position on the three-phase feeder (66); and determining a specific fault location on a faulty line according to the steady-state signal and the transient signal (67). The method effectively detects and displays a single-phase ground fault on a low current grounded power-distribution network.

An apparatus and method for identifying a presence of a short circuit in a battery pack. A fault-detection apparatus for a charging system that rapidly charges a collection of interconnected lithium ion battery cells, the safety system includes a data-acquisition system for receiving a set of data parameters from the collection while the charging system is actively charging the collection; a monitoring system evaluating the set of data parameters to identify a set of anomalous conditions; and a controller comparing the set of anomalous conditions against a set of predetermined profiles indicative of an internal short in one or more cells of the collection, the controller establishing an internal-short state for the collection when the comparing has a predetermined relationship to the set of predetermined profiles.

A control apparatus for a multi-phase rotary machine includes a control unit and a plurality of power supply systems including respective inverter units. When a short-circuiting failure occurs in one of the systems due to an ON-failure in any one of FETs in an inverter unit of the failure system, the control unit stops driving of the rotary machine by bringing all the FETs in the failure system into the OFF state. The control unit controls FETs of the non-failure system such that a brake torque generated in the failure system is cancelled or the influence of the brake torque exerted on the driving of the motor is reduced.

A leakage detection circuit for an electric vehicle includes a battery pack, first and second leakage detection switches, a controller, a leakage detection resistor, a voltage detector, and a calculator. The first and second leakage detection switches are connected to the high and low voltage sides of the battery pack, respectively. The battery pack includes a plurality of batteries that are connected in series. The midpoint of the leakage detection resistor is connected to the ground via the first and second leakage detection switches. The controller alternately turns the first and second leakage detection switches ON. Thus, the voltage detector detects leakage voltage values that are generated in the leakage detection resistor. The controller turns the first and second leakage detection switches ON and OFF, respectively, to detect a first leakage voltage value of the leakage voltage values. On the other hand, the controller turning the first and second leakage detection switches OFF and ON, respectively, to detect a second leakage voltage value of the leakage voltage values. Consequently, the calculator detects leakage based on the first and second leakage voltage values.

A system and method of monitoring a plurality of electrical assets comprise an electricity distribution infrastructure, including a plurality of electrical asset sensors coupled to the electrical assets for monitoring an operating condition of the electrical assets as well as any fault conditions. The sensors may include a current transformer for obtaining a current waveform, a GPS receiver for applying a synchronized time-stamp to the waveform data, and a mesh network radio for transmitting the time-stamped waveform data. Data from the plurality of sensors may be encrypted and transmitted over a mesh network to one or more gateways that are in communication with a central command processor. In response to an abnormal operating condition of any electrical asset, the central command processor may determine a probable fault location, a probable fault type, and a fault response.

An electronic battery tester for testing a storage battery that includes a battery housing with a plurality of electrochemical cells electrically connected to terminals of the battery is provided. The battery tester includes positive and negative connectors that can connect to the battery terminals. The tester also includes a temperature sensor that can measure a temperature of an individual electrochemical cell of the plurality of electrochemical cells. Processing circuitry, which is coupled to the temperature sensor, is configured to test the battery using the positive and negative connectors and to provide an output related to the temperature measured by the temperature sensor. The present invention also provides a battery charger with an integrated battery cell temperature sensor.

A ground fault detector and detection method for a vehicle that can determine the cause of the occurrence of a ground fault after detecting the presence of the ground fault. The output terminal of a high-voltage battery is connected to one side of a coupling capacitor. In operation, a pulse signal is applied to a measurement point on the other side of the coupling capacitor, and the voltage generated at that point is detected. Whether the high-voltage battery or the electrical equipment units are grounded is determined. To determine the cause of the ground fault, the oscillation frequency of the square-wave pulse signal is changed and applied to the measurement point. From the change in voltage amplitude detected, it is determined whether the cause of the ground fault is a resistive or a capacitive ground fault, according to the change in the impedance of the battery or the units.

Methods and apparatuses for estimation of a state-of-health in a battery are disclosed. An example method comprises: determining if a terminal voltage of the chemical battery differs from a calculated terminal voltage; in response to determining that the terminal voltage of the chemical battery differs from the calculated terminal voltage, calculating a range of voltages by taking the convolution of a terminal current of the chemical battery with a range of impulse responses from a look up table of impulse responses corresponding to different states-of-health; comparing the terminal voltage of the chemical battery with the range of calculated voltages to determine a second impulse response that corresponds to the case where the terminal voltage matches the calculated voltage; and using the look up table of impulse responses corresponding to different states-of-health to determine the state-of-health of the chemical battery from the second impulse response. Other embodiments are described and claimed.

A circuit and method thereof for measuring leakage current are described. The circuit includes a pre-charge device subject to a first backbias voltage and a leakage test device subject to a second backbias voltage. The leakage test device is coupled to the pre-charge device. The leakage test device is biased to an off state. A differential amplifier is coupled to the pre-charge device and the leakage test device. A delay unit is coupled to the differential amplifier and to an input of the pre-charge device. The pre-charge device is turned on and off at a frequency that corresponds to said leakage current.

There are provided a method and a system for real time monitoring of a powered on electrical network in a facility in order to detect an electrical anomaly while the electrical network is in use. The system comprises a sensor data receiver for receiving real time sensor data including at least one measured value measured in real time by at least one sensor installed on a conductor of the electrical network in the facility while the electrical network is in use; an anomaly detector for retrieving an anomaly detection rule from an anomaly detection rule database, the rule having an identification of a required input, a formula, and a threshold reference value, for a detection of an anomaly; receiving the real time sensor data from the sensor data receiver and extracting at least one relevant measured value from the at least one measured value using the identification of the required input; comparing the at least one relevant measured value to the threshold reference value according to the formula to determine one of a presence and an absence of the anomaly in the real time sensor data; an event generator controlled by the processor for retrieving and providing anomaly monitoring data if the anomaly is determined to be present by the processor, the anomaly monitoring data including an indication of a monitoring course of action to be carried out to address the anomaly determined to be present.

Various systems and methods for determining micro-shorts are disclosed. For example, some embodiments of the present invention provide battery systems including a determination of potential micro-shorts based on rate of change of state of charge. Such battery systems include: a battery, a processor, and a computer readable medium. The computer readable medium includes instructions executable by the processor to: determine a rate of change of the state of charge of the battery; compare the rate of change of the state of charge of the battery against a threshold; and indicate a potential failure where the result of the comparison is beyond the threshold.

An electronic battery tester for testing a storage battery that includes a battery housing with a plurality of electrochemical cells electrically connected to terminals of the battery is provided. The battery tester includes positive and negative connectors that can connect to the battery terminals. The tester also includes a temperature sensor that can measure a temperature of an individual electrochemical cell of the plurality of electrochemical cells. Processing circuitry, which is coupled to the temperature sensor, is configured to test the battery using the positive and negative connectors and to provide an output related to the temperature measured by the temperature sensor. The present invention also provides a battery charger with an integrated battery cell temperature sensor.

An isolation monitor is disclosed in which a switchable bias voltage is imposed on a chassis ground. An isolation voltage is measured when a bias voltage is applied. When there are no electrical faults, the isolation voltage swings up and down to known values. When a fault occurs, the isolation voltage will not to swing to the known values, and thus the isolation resistance can be measured and alarm generated if the isolation resistance falls below a threshold value.

In one embodiment, an AC ground fault detector system senses an AC signal indicative of an unintended electrical path between a load driven by a power source and a reference potential using a capacitively coupled circuit.

The present invention is directed to an electrical device configured to be disposed in an electrical distribution system between a source of electrical power and an electrical load. The electrical distribution system includes at least one line hot conductor, a line neutral conductor, and a line ground conductor. The line neutral conductor and the line ground conductor are connected to earth ground at a termination point in the electrical distribution system. The electrical load includes at least one load hot conductor, a load neutral conductor, and a load ground conductor. The device comprises a power supply coupled to the power input mechanism. The power supply comprises at least one DC voltage output terminal and a reference terminal coupled to the line ground termination element. A voltage parameter detection circuit is configured to take a first voltage reading from a first termination element of the plurality of line termination elements and a second voltage reading from a second termination element of the plurality of line termination elements to derive at least one voltage parameter therefrom. The first voltage reading and the second voltage reading are referenced to the reference terminal. The circuit interrupter is driven into the tripped state if the at least one voltage parameter does not meet a predetermined condition, the voltage parameter detection circuit being operational when the reference terminal is not at an earth ground potential.

A power line communication-based aircraft power distribution system may allow for both power line communication (PLC) technology and spread spectrum time domain reflectometry (SSTDR) technology to be utilized in aircraft power distribution systems to achieve key maintenance functions. Unlike conventional power distribution systems, which may, for example, use only SSTDR for fault detection, the present invention includes a hardware platform that may allow both the PLC and the SSTDR to be utilized in aircraft power distribution systems to achieve key maintenance functions, such as real time wire fault location, and cost and weight savings. Further, unlike conventional power distribution systems, which may only detect and locate damage in feeder conductor wire sections before the power is applied to the load, the power distribution system of the present invention may permit real time wire fault location.