2494results about "Emergency protection detection" patented technology

The current invention is an automatic AC power interruption system built into a portable power strip or a portable casing or integrated into an appliances control circuitry. The invention monitors the environment for hazard alarms, for example, a T3 signal smoke detector alarm, and responds by tripping open the power supply circuit to the power strip's receptacles and thus interrupts AC power to the protected appliances the user has chosen to plug into them. One alternate form of the invention uses a portable casing that can be plugged into a power receptacle and, when a hazard alarm is detected, trip off the nearest GFCI. Other alternate forms of the invention are integrated within an individual appliance's control circuitry and may interrupt power using a built-in switch or by tripping off the nearest GFCI device. The invention's purpose is to help prevent death, injury, and property damage by preventing fires or facilitating fire suppression; more particularly, by interrupting electrical power to problematic appliances, such as toasters, space heaters, battery chargers, stoves, and motors, when a hazardous condition alarm is emitted. It further interrupts power to the problematic appliances when a detector emits an alarm indicating toxic fumes, natural gas, radon, carbon monoxide, or whatever other detector-alarm the consumer installs in the area to be protected.

A dc breaker is connected in a main current path between a first dc circuit and a second dc circuit. The dc breaker has a primary current path connected to the main current path. A mechanical interrupter switch and an electronic breaker switch are connected in series in the primary current path. A secondary current path is provided in parallel with the primary current path. A capacitor is arranged in the secondary current path so as to be connected in parallel with the series-connected switches of the primary current path.

A voltage detector includes a zener diode having a cathode connected to a detect terminal of the voltage detector, a junction field effect transistor having an input terminal connected to an anode of the zener diode, and a resistor connected between an output terminal and a control terminal of the junction field effect transistor. When the voltage on the detect terminal is higher than the breakdown voltage of the zener diode, the junction field effect transistor produces a current flowing through the resistor, and thereby a detection signal can be obtained from the voltage across the resistor.

An apparatus for detecting a fault in a power relay of an inverter is disclosed. The apparatus for detecting a fault in a power relay includes: a voltage sensor configured to measure a voltage of a DC link; a current sensor configured to measure an output current applied to an inverter stage; a storage unit configured to store resistance of an initial charge resistor, a time constant of a capacitor, and a reference voltage measured when voltage drop of the DC link does not occur; and a controller configured to determine, when the voltage drop of the DC link occurs, the presence or absence of a fault in the power relay based on a difference between the reference voltage and a voltage measured after lapse of a period corresponding to the time constant.

An electrical switching apparatus includes a plurality of poles each having a Rogowski coil and a conductor passing through an opening thereof, and a processor circuit including a sensor circuit including a plurality of inputs each electrically interconnected with an output of the Rogowski coil of a corresponding pole. The sensor circuit further includes a number of outputs having values each corresponding to current flowing through the conductor, a memory including for each corresponding pole an offset value and a gain correction factor for the sensor circuit, and a gain correction factor for the Rogowski coil, a number of routines, and a processor cooperating with the sensor circuit and the routines to provide for each pole a corrected current value as a function of a corresponding one of the values, the sensor circuit offset value and gain correction factor, and the Rogowski coil gain correction factor.

A circuit is disclosed for disconnecting a power source upon the detection of a leakage current from one of a first and a second wire connected to the power source. A sensing conductor is located adjacent to one of the first and second wires for sensing a leakage current from one of the first and second wires. A disconnect switch is interposed within the first and second wires connected to the power source. A disconnect switch control circuit is connected to the sensing conductor for opening the disconnect switch upon the presence of a leakage current from the sensing conductor. The disconnect switch control circuit operates solely from the leakage current from the sensing conductor.

A power supply unit includes a battery, a motor which is driven by the battery, an electric power converting device which is provided between the battery and the motor, a simulated electric leak generating device which generates an electric leak state between the battery and a vehicle body, and an electric leak detecting device which detects a simulated electric leak. A diagnostic system which performs a diagnosis of operating performance of the electric leak detecting device includes an opening/closing device which connects/disconnects the electric power converting device to/from the battery, and an opening/closing detecting device which detects opening/closing of the opening/closing device and which outputs a result of detection to the simulated electric leak generating device and the electric leak detecting device. When opening/closing of the opening/closing device is detected by the opening/closing detecting device, both generation of a simulated electric leak and detection of an electric leak are retried.

The invention relates to a novel approach for the protection of electrical circuits from ground faults and parallel and series arc faults in a fully solid-state circuit configuration. Solid-state circuits and methods of use are described that provide the key functions of low-voltage DC power supply, mains voltage and current sensing, fault detection processing and high voltage electronic switching.

An inverter system which converts DC input into AC output and supplies the AC output to a load such as an FL tube detects change in a circuit current due to anomaly such as discharge without contacting with a current route. Relating to an inverter which converts DC input into AC output and supplies the AC output to a load, change in a circuit current of the inverter is detected through the medium of magnetic flux change due to the change in the circuit current caused by discharge. For example, if change in a current occurs in the circuit current of the inverter by disconnection discharge or ground-fault discharge occurring in a current route including a load of the inverter, magnetic flux change occurs in circuit wiring and a space of a core gap of a transformer of the inverter. The change in the circuit current is detected through the medium of the magnetic flux change without contacting with the circuit wiring or the transformer.

The invention discloses an energy-feeding flexible grounding device for a power distribution network, a fault arc extinction method and a direct-current-side-voltage control method and system of the energy-feeding flexible grounding device. The fault arc extinction method includes the steps that when a single-phase grounding fault is generated, a neutral point of the power distribution network is grounded through a flexible grounding device, the flexible grounding device is controlled to inject a resistive current and a reactive current into the neutral point in sequence, a fault feeder line is judged, and arc extinction of a fault point is promoted. The direct-current-side-voltage control method includes the step that energy exchanging between the flexible grounding device and the power distribution network is achieved through a direct-current-side capacitor voltage outer loop and a three-phase input current inner loop, and therefore it is guaranteed that the direct-current-side voltage is constant. By means of the direct-current-side-voltage control method, the problems that the direct-current-side voltage of a traditional flexible grounding device is difficult to stabilize, the harmonic content of an injected current is high, and system stability is poor can be solved; by switching control modes, the fault feeder line can be accurately identified, an instant grounding fault electric arc can be eliminated, and the power supply reliability of the power distribution network can be improved.

The invention discloses a method for processing interphase short circuit of a three-phase non-effective grounding power supply system. The method comprises the following steps: when two-phase or three-phase interphase short circuit occurs in a line, maintaining one fault phase of the line to be conducted and tripping off other fault phases, and artificially grounding the other fault phase conducted with the fault phase or directly utilizing the existing grounding point; enabling a live-line phase or a neutral point of the three-phase non-effectively grounded power supply system except the fault phase to be circularly connected and disconnected with the ground, so that the live-line phase or the neutral point and the fault phase form a closed loop and generate a current pulse, and detecting the current pulse by a controlled switch; when a certain controlled switch reaches a trigger condition and cuts off a line, eliminating a fault. According to the method, the inter-phase short-circuit fault point interval can be quickly positioned, the fault can be automatically, quickly and accurately removed, the processing quality of the inter-phase short-circuit fault can be well improved, and the power supply safety is improved.

A ground fault detection system is provided. The ground fault detection system includes a magnetic core having first and second primary legs and a secondary leg disposed between the first and second primary legs. The ground fault detection system also includes first and second primary windings disposed around the first and second primary legs respectively and configured to introduce current in the first and second primary legs. Further, the ground fault detection system includes first and second secondary windings disposed around the first and second primary legs respectively and configured to detect a ground fault based upon a magnetic flux generated in response to the introduced current.

Circuit interrupter positioned between supply circuit and load circuit includes fault detection circuit that senses wave forms to the load circuit, fault processing circuit that detects presence of fault and generates fault output signal when fault detected, and control circuit switch connected to fault processing signal output, wherein control circuit switch is opened by presence of fault output signal, thus isolating load circuit from supply circuit. Preferably fault processing circuit and control circuit are optically linked, such that when fault is detected, control circuit switch is opened by optical fault output signal, thus isolating load circuit from the supply circuit. Circuit interrupter may couple another circuit interrupter via power distribution control unit, optionally manageable remotely via automated control interface.

Systems and methods are configured for detecting and locating simultaneous faults in a distribution network having primary and secondary buses connected with two-terminal sections. The measured three-phase voltages and currents from the primary buses are received via a communication network, and the series impedances and shunt admittances and the pre-fault connectivity topology are retrieved from the storage. Simultaneous faults are determined to occur by verifying at least one phase of at least three buses having phase current mismatches determined as the differences between the measured values and calculated values using normal topology and phase voltages that are greater than a threshold. A location for each fault is determined individually if the faults are occurring at non-adjacent sections in the distribution network, or jointly if the faults are occurring at adjacent sections in the distribution network. Faulted line sections are isolated by activating switching operations for connected switches to the faulted line sections that communicatively linked to distribution system grid via communication network.

The hand-held electronic device includes a central processing unit, a memory unit, a state-detecting unit, a state-determining unit, a main power supply unit, a standby power supply unit, and a power supply switching unit. After determining the presence of a fall state, the state-determining unit will output a fall prevention instruction and which causes the central processing unit to enter a low-potential current mode; meanwhile, the power supply switching unit monitors power output and continues to supply low-potential power. In case of a fall of the hand-held electronic device, the device and method protect operation data and reduce the otherwise power-consuming current. The less power-consuming current is conducive to the reduction of capacitance required for a backup battery. The low-potential current mode is effective in reducing the time taken to recover the operation mode of the electronic device.

An overcurrent detection circuit includes a current detection resistor that generates a voltage in proportion to current flowing through a switching element and a comparator that compares the voltage detected via the current detection resistor and a reference voltage generated by a reference voltage generation circuit to thereby detect overcurrent flowing through the switching element. In particular, the reference voltage generation circuit includes: a first resistance voltage dividing circuit that resistance-divides a standard voltage by connecting, in series, two types of resistors having different temperature characteristics; a second resistance voltage dividing circuit that resistance-divides the standard voltage by connecting, in series, resistors having the same temperature characteristics; and an instrumentation amplifier that generates the reference voltage according to the difference between the divided output voltages of the first and second resistance voltage dividing circuits.