Embodiments include a system, control process, and method for improving the reliability of mineral insulated electrical cables for use in oil and gas industry applications. The embodiments may include a PWM variable speed drive having an optimized operating frequency, a sine wave filter connected to an output of the drive and designed to mitigate reflective voltage wave spikes from the drive's PWM voltage pulses, a mineral insulated electrical heater cable connected to the filter, and an external controller for receiving voltage, current, and temperature feedback to create a voltage set point at which the drive operates. The embodiments may (i) mitigate common failure mechanisms of mineral insulated cables operating at a medium voltage level and in a temperature range of from 200 C. to 700 C.; (ii) extend the range of application of mineral insulated cables; and (iii) prevent high voltage spikes from causing damage to the insulant material of heater cables.

A cable including a power conductor configured to transmit electrical power between a first device and a second device, a first data conductor configured to transmit data between the first device and the second device, and a first bimetallic switch coupled to the first data conductor and configured to mitigate current flowing through the first data conductor if a temperature of the first bimetallic switch exceeds a predefined first trip temperature, wherein the opening of the first data line indicates a fault condition to a device to which the cable is connected, whereby electrical power flowing through the power conductor is resultantly mitigated.

A Leakage Current Detection and Interruption (LCDI) device, for use as a safety device for a load cable. The LCDI circuit card assembly incorporates a load input cavity having fire retardant materials surrounding the load input terminals, a separated containment cavity structure for a first Metal Oxide Varistor (MOV), and a contact actuator which encases the switch or contact arm at the source input section of the LCDI. The circuit design incorporates redundant safety features for containment of spurious ignitions.

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.

The disclosure describes a system for monitoring and mitigating damage to electrical utility structures and the surrounding environment. In some embodiments, the system includes fire boxes, arc sensors, angle switches, and disconnect switches configured to generate alert signals when a hazard is detected. In some embodiments, the system includes cameras configured to detect a hazard such as a fire or moving object. In some embodiments, the system includes light transmitters and light receivers positioned at a predetermined location away from power lines to detect objects that interrupt a line of site. In some embodiments, the system can electrically isolate a power line before a detected hazard impacts a power line.

A line protection device includes terminals to connect the line protection device in series with an electric line. A current sensor of the line protection device senses a value of electric current through the electric line. A digital filter circuit of the line protection device performs digital filtering of the value of electric current. Depending on the digitally filtered value of the electric current, a switch control circuit of the line protection device controls a switch to interrupt flow of the electric current through the line.

A line protection device includes a current sensor, a digital filter circuit, a switch control circuit, and a non-volatile memory circuit. The current sensor is adapted to a sense a value of electric current through the electric line. The digital filter circuit is adapted to perform digital filtering of the value of electric current. The switch control circuit is adapted to control a switch to interrupt flow of the electric current through the electric line depending on the digitally filtered value of the electric current. The non-volatile memory circuit is adapted to store a state of the digital filter circuit.

When supplying electric power to a load from a power supply via a parallel circuit of two electrical wires having the same wiring resistance, a vehicular power supply control device uses a current measurement unit in intelligent power devices (IPDs) to measure a passing current flowing in a semiconductor switching device in each of the electrical wires. Then, in order to match the temperatures of the electrical wires as estimated by a present temperature estimation unit base on the measured current, a target duty ratio in a PWM control for reducing the passing current in the semiconductor switching device of the IPD on one electrical wire is calculated in a target duty ratio calculation unit, and the semiconductor switching device of the one IPD is turned on and off by a PWM/DC control and shutoff determination unit with the calculated target duty ratio.

A concomitant impedance protection method for a half-wavelength power transmission line includes that: three-phase currents and three-phase voltages of a relay protection device mounting position at an M side and a relay protection device mounting position at an N side of the half-wavelength power transmission line are acquired respectively; it is judged whether starting amounts of an M side and an N side meet starting conditions or not; a failure point F is determined according to a time difference when the starting amounts of the M side and the N side meet the starting conditions; and a relay protection action of the half-wavelength power transmission line is started according to concomitant impedance of the half-wavelength power transmission line. According to the method, a failure may be located by a time-difference method according to a characteristic of the failure, by compensating the voltages and currents on two sides of the line to construct concomitant impedance, and failures in the region of line can be correctly reflected. Since concomitant impedance protection effectively utilizes two-terminal electrical information, the fault can be quickly and reliably operated in the line region, misoperation on the failures out of the line region can be avoided, and the protection has relatively higher sensitivity.

A self-powered recloser includes a circuit breaker, an electrical actuator, an electrical generator, a capacitor, and a lever. When in an on state, the circuit breaker harvests power from a medium voltage line required to actuate its movable contact to interrupt current flow in the medium voltage line, and when in an off state, it does not harvest power from the medium voltage line. The electrical actuator is configured to transition the circuit breaker from the off state to the on state. The capacitor when charged is configured to provide the electrical actuator with the electrical power required to transition the circuit breaker from the off state to the on state. The lever is configured to be moved by an operative. Movement of the lever is configured to charge the capacitor via the electrical generator.