Real-time detection of high-impedance faults in a distribution circuit is described. The real-time detection of high-impedance faults includes two steps. First, adaptive soft denoising is employed to perform a filtering process on a healthy dataset, and to determine a threshold. This reduces the rate of false alarms. Second, faulty datasets are prefiltered via adaptive soft denoising, then the denoised signals are processed via discrete wavelet transform to perform high-impedance fault detection using the threshold.

An overheat-protection device with a cord that includes a transmission wire to transmit electrical power and a sensor wire to transmit a signal, a plug attached to an end of the cord, and a thermistor includable in the plug and connected to the sensor wire. The signal may be received and/or analyzed by a sensing device, which may control a switching device to open and/or close a power circuit. The thermistor may detect a level of heat, which may be communicated as a signal via the sensor wires. The signal may be definable by the thermistor varying a level of resistance to the signal responsive to the level of detected heat. The thermistor may be a NTC thermistor and may be constructed from a thermal plastic or a ceramic.

Circuits, methods, and apparatus that may provide power supply voltages in a safe and reliable manner that meets safety and regulatory concerns and does not exceed physical limitations of cables and other circuits and components used to provide the power supply voltages. One example may provide a cable having a sufficient number of conductors to provide power without exceeding a maximum current density for the conductors. Another example may provide a cable having more than the sufficient number of conductors in order to provide an amount of redundancy. Current sense circuits may be included for one or more conductors. When an excess current is sensed, a power source in the power supply may be shut down, the power source may be disconnected from one or more conductors, or both events may occur.

A monitoring method for an electrical energy transfer device which has a first phase conductor and a second phase conductor, includes the following steps: a temperature of the first phase conductor is compared with the temperature of the second phase conductor and a signaling is performed if there is a deviation between the temperatures. The electrical energy transfer device is, for this purpose, equipped at the first phase conductor with a first temperature sensor and at the second phase conductor with a second temperature sensor.

An electrical protection circuit breaker comprises a microprocessor chip part, a circuit breaker part connected between a power line and a power supply, a temperature detection part for detecting a temperature of the power line, a current detection part for detecting a current of the power line, and a voltage detection part for detecting a voltage of the power line. A memory of the microprocessor chip part stores a data collection S=f(temp, I, V, Δtime), wherein S represents a diameter of the power line, temp represents the temperature, I represents the current, V represents the voltage, and Δtime represents a set time period. The microprocessor chip part matches electronic data of real-time temperature changes, electronic data of an import current, and electronic data of a voltage with data sets in the data collection, and sets a corresponding safety protection current according to matching results.

An example embodiment is a voice appliance including: a plurality of user interface devices comprising at least a microphone and a speaker; a plug for receiving power to the appliance or load; and a communication subsystem configured for wired communication with an electrical receptacle through the plug when plugged into the electrical receptacle. An electrical receptacle for connection to power lines comprises: at least one plug outlet configured to provide DC output, wherein the at least one plug outlet is configured to provide access to a wired communication network defined by at least one of the power lines. The plug outlet can be a Universal Serial Bus (USB) plug outlet to connect to a mobile device or a removable USB memory device. An intelligent junction box at the circuit breaker panel is configured to perform dynamic power allocation and power line communication.

A power supply system includes: a battery; a master device supplied with power from the battery; and a slave device supplied with power from the master device via a first power supply line. The slave device supplies power to a load via a second power supply line. The master device estimates a temperature of the second power supply line. When the estimated temperature of the second power supply line is higher than a second cutoff threshold, power supply via the second power supply line is cut off.

According to an embodiment, a current monitoring circuit includes a signal shaping unit configured to receive a current sense signal and provide a modified current signal; a filter configured to receive the modified current signal and to provide a respective filtered signal; a comparator configured to receive the filtered signal and a threshold value and to indicate when the filtered signal exceeds the threshold value. The signal shaping unit is configured to calculate a level of the modified current signal from a corresponding level of the current sense signal in accordance with non-linear function.

A time alignment method for a differential protection device, the differential protection device and a differential protection system are disclosed. The time alignment method includes obtaining a plurality of current sampled values and a count value of each current sampled values; resampling the plurality of current sampled values with sampling frequency of J points/cycle to obtain a plurality of current resampled values; and performing Fourier transform on the plurality of current resampled values to obtain a plurality of temporally arranged current Fourier values, the plurality of current Fourier values includes a reference current Fourier value corresponding to the sampling moment of the current sampled value whose count value is the first value in the plurality of current sampled values, and the reference current Fourier value is determined based on the reference current resampled value and the J−1 current resampled values that temporally arranged before the reference current resampled value.

The application relates to direct current, DC, charging cable including two DC conductors configured for transmitting electrical energy between an electrical vehicle and a charging device, at least a signal line having a first signal line end and a second, opposite signal line end and a control device, the first signal line end is connected at a first connection point to one of the DC conductors, and the control device is configured for measuring a voltage difference between the second signal line end and a second connection point of the one of the DC conductors distant to the first connection point for determining a temperature of the DC charging cable.