A secondary battery protection circuit for a secondary battery includes: a reference voltage circuit configured to generate a reference voltage by using a depletion-type transistor and a transistor unit of enhancement type connected in series with the depletion-type transistor; a voltage divider configured to output a detection voltage obtained by dividing a power source voltage of the secondary battery; a detection circuit configured to detect an abnormal state of the secondary battery based on the reference voltage and the detection voltage; a first adjustment circuit configured to adjust a size ratio of the depletion-type transistor to the transistor unit based on threshold voltages of the depletion-type transistor and the transistor unit; and a second adjustment circuit configured to adjust the detection voltage based on the reference voltage after adjusting the size ratio.

An electrical protection system arranged to detect and isolate faults either in a electrical power distribution. The system comprises at least a first busbar and a second busbar in electrical communication with each other through s powerline having a first end electrically coupled to the first busbar by a first circuit breaker and a second end connected to the second busbar by a second circuit breaker. It is connected to the at least two busbars, and configured to simultaneously collect/determine a first electrical quantity at each of the at least two busbars and compare the collected/determined electrical quantity to a second. When the first electrical quantity value less than the second quantity value, the system causes the first and second circuit breakers to open so as to decouple the electrical connection between first and second busbars. The system 100 detects and isolates fault efficiently while using voltage measurements.

A surge protection system includes a receptacle body, at least one power output jack, a power obtaining device, at least one surge protection module, a microcontroller unit, and a surge detection circuit. The at least one surge protection module includes a housing, a memory element, and a surge protection circuit that includes a surge absorption element and a thermal fuse connected in series and parallel. The surge absorption element absorbs a surge inputted from an external power supply, and the memory element records a number of surges carried by the surge absorption element. When the surge enters the surge protection system from the external power supply, the surge absorption element absorbs the surge, and the surge detection circuit outputs a signal to the microcontroller unit that writes the number of surges carried by the surge absorption element into the memory element.

A semiconductor device includes first and second protection circuits. The first protection circuit includes a timer circuit, a voltage detection circuit, and a discharge element. The second protection circuit includes a discharge circuit. The timer circuit is connected between a first pad on a power supply potential side and a second pad on a reference potential side. The voltage detection circuit is connected between the first and second pads on an output side of the timer circuit. The discharge element is connected between the first and second pads on an output side of the voltage detection circuit. The discharge circuit is connected between a third pad on the power supply potential side and a fourth pad on the reference potential side on the output side of the timer circuit.

In accordance with an embodiment, a circuit includes: a supply pin and an output pin for connecting a load, and a configuration pin; a semiconductor switch connected between the supply pin and the output pin and configured to establish or to block a current path between the supply pin and the output pin depending on a control signal; and a control circuit configured to generate the control signal for the semiconductor switch taking account of a first parameter, and set the first parameter depending on a component parameter of an external component connected to the configuration pin. The first parameter is set to a first standard value when the component parameter is less than a first threshold value, and the first parameter is set to a second standard value when the component parameter is greater than a second threshold value.

An auto recovery circuit breaker (ARCB) device is disclosed that may include a step-down transformer which may provide a low voltage AC test signal to detect a fault in a phase line or neutral of an electric circuit. A first current transformer (CT) is positioned on the first line, and a second CT is positioned on the second line. Each of the first CT and the second CT may sense a current flowing through the electric circuit, and detect an earth leakage through the electric circuit. A microcontroller is configured to: monitor the analog signal in the circuit, detect earth leakage before powering ON the circuit, detect output short before power ON, and upon detection of a fault removal in the electrical circuit, turn ON a relay. Once turned ON, the ARCB device may continue test by sensing the CT’s provided in the phase and neutral lines.

An electrical system forming part of a solar power plant is described. The electrical system includes a plurality of photovoltaic (PV) panels, a power converter, and a controller. In response to a detected electric arc on the DC side of the power converter, the controller is configured to enable a short circuit state of the power converter by controlling semiconductor switches of the power converter (e.g., turning on some or all of the semiconductor switches) to create a short circuit between DC input terminals of the power converter. The short circuit path though the power converter will extinguish the detected electric arc in the connected DC circuit.

Communication enabled circuit breakers are described. Methods associated with such communication enabled circuit breakers are also described. The communication enabled circuit breakers may include one or more current sensors. The one or more current sensors may be disposed in a clip. The clip may be coupled to a line side phase connection, and the clip may be shielded to attenuate signals.

Systems, methods, and computer-readable media are disclosed for autonomous restoration of power systems after natural disasters. An operating mode of a circuit breaker that is in a power system grid and that is coupled to other circuit breakers in the power system grid via communication channels is determined. Based on determining that the operating mode is a normal operating mode, data to parameterize a plurality of power grid restoration scenarios is collected at the circuit breaker. Based on determining that the operating mode is an exception mode, measurement data that includes current and voltage data is received at the circuit breaker, and one of the power system grid restoration scenarios is initiated at the circuit breaker. The power system grid error restoration scenario is selected based at least in part on a status of the plurality of communication channels coupled to the circuit breaker and on the measurement data.

A circuit breaker device or circuit breaker system may include a series connection of a semiconductor switch and an isolating contact system, for a low voltage electrical circuit, in which the magnitude of the current is determined.