A method and a photovoltaic inverter for determining the insulation resistance of a photovoltaic system relative to ground are provided. The voltage required for the measurement can be provided by an intermediate circuit in the form of an intermediate circuit voltage and a measuring device is designed to actuate an input short-circuit switch for short-circuiting a DC input with an AC disconnector open, as a result of which the intermediate circuit voltage can be applied to the DC input in the reverse direction. The measuring device is configured to record measured voltages with a switch of a voltage divider open and closed, and to determine the insulation resistance from the measured values of the two measured voltages recorded with the switch of the voltage divider open and closed.

A method for monitoring a line for a change in ambient conditions. The line includes a measurement line of a predetermined length which has a measuring conductor enclosed in an insulation with a known dielectric coefficient. An analog signal of defined frequency is generated and injected at a feed site. The signal is reflected at a predetermined reflection site and a resulting signal amplitude is measured at a defined measuring point. A measure for the ambient condition, particularly a temperature, is determined from the signal amplitude.

A voltage detection unit includes a voltage detection terminal, a housing including a terminal accommodating concave and a cover to he attached to the housing and to cover the voltage detection terminal accommodated in the terminal accommodating concave. The cover includes an extension piece extending in a first direction. The housing includes an accommodating hole to accommodate the extension piece, and a guide portion including an inclined surface and a guide surface. The inclined surface has a first end in the first direction and a second end and is inclined with respect to the first direction such that the first end is provided closer to the accommodating hole than the second end in a second direction perpendicular to the first direction and being parallel to the housing. The guide surface is continuous with the inclined surface and an inner wall surface of the accommodating hole.

A voltage detection unit includes a voltage detection terminal including a first portion configured to be conductively connected to a detection target and a second portion, a housing having a plate shape and including a terminal accommodating concave configured to accommodate the voltage detection terminal, a cover configured to be engaged with the housing at a temporary locking position at which the cover does not cover the first portion of the voltage detection terminal accommodated in the terminal accommodating concave and at a final locking position at which the cover covers the first portion and an electric wire conductively connected to the voltage detection terminal at the second portion and configured to, when the voltage detection terminal is accommodated in the terminal accommodating concave, be drawn out from the housing.

A voltage detection unit includes a voltage detection terminal, an electric wire, a housing including a terminal accommodating concave and an electric wire accommodating concave, and a cover. The cover includes an extension piece extending in a first direction in which the cover is attached to the housing. The housing includes an accommodating hole to accommodate the extension piece. The electric wire accommodating concave includes an inclined surface and a guide surface. The inclined surface is inclined with respect to the first direction such that a first thereof end is provided closer to the accommodating hole than a second end thereof in a second direction perpendicular to the first direction and being parallel to the housing. The guide surface is continuous with the inclined surface and continuous with an inner wall surface of the accommodating hole.

A voltage detection unit includes a voltage detection terminal configured to be conductively connected to a detection target, an electric wire conductively connected to the voltage detection terminal and a housing having a plate shape and including a terminal accommodating concave configured to accommodate the voltage detection terminal, an electric wire accommodating concave defined by a first groove side wall, a second groove side wall and a groove bottom surface, and configured to accommodate the electric wire and to guide the electric wire out of the housing and an electric wire restricting portion configured to hold the electric wire between the electric wire restricting portion and the groove bottom surface and to prevent the electric wire from being displaced out of the electric wire accommodating concave.

DeepOPF-V, a deep neural network (DNN)-based voltage-constrained approach for solving an alternating-current optimal power flow (AC-OPF) problem, is used to determine an operating point of an AC electrical power system. DeepOPE-V advantageously uses two DNNs to separately determine voltage magnitudes and voltage phase angles of buses in the system without cross-over operations between the two DNNs. A computation complexity is reduced when compared to using a single DNN for generating both the magnitudes and phase angles, allowing high computation efficiency achieved by DeepOPE-V. Remaining variables of the system are computed based on the determined magnitudes and phase angles. A solution for the operating condition is predicted. A fast post-processing (PP) method is developed to improve the feasibility of the predicted solution. The PP method uses linear adjustment to adjust the predicted solution to improve the solution feasibility while enabling fast execution of the PP method.

Various embodiments of an apparatus, methods, systems and computer program products described herein are directed to an Analytics Engine that receives one more signal files that include neural signal data of a user based on voltages detected by one or more electrodes on a set of headphones worn by a user. The Analytics Engine preprocesses the data, extracts features from the received data, and feeds the extracted features into one or more machine learning models to generate determined output that corresponds to at least one of a current mental state of the user and a type of facial gesture performed by the user. The Analytics Engine sends the determined output to a computing device to perform an action based on the determined output.

Evaluating the performance of an X-ray tube by: recording arcing events that occurred during the use of the X-ray tube; classifying the arcing events by severity; generating, on the basis of the classified arcing events, a first growth pattern for occurrences of arcing events; and determining a level of bubbles in the X-ray tube by finding, on the basis of the first growth pattern, a matching second growth pattern associated with a known level of bubbles in the X-ray tube. An X-ray tube may be checked and replaced in a timely manner, without the need for an on-site inspection, by remotely predicting trends or patterns for growth of levels of bubbles in the X-ray tube.

A sensor for a separable connector comprises a plug body comprising an insulating resin, the plug body configured to be inserted into the separable connector to encase a high voltage conductor disposed in the separable connector. The sensor also includes one or more high voltage capacitors encased by the insulating resin and configured to be electrically coupled to the separable connector at a first end portion when the plug body is inserted and one or more low voltage capacitors electrically coupled in series to the one or more high voltage capacitors to form a capacitive voltage divider. The sensor also includes a low voltage connection configured to provide a low voltage signal corresponding to a high voltage signal present in the separable connector, the low voltage connection comprising a coaxial contact having a first metal contact and a second metal contact.