The invention relates to a method and a photovoltaic inverter (2) for determining the insulation resistance (R.sub.iso) of a photovoltaic system (1) relative to ground (PE). According to the invention, the voltage required for the measurement can be provided by the intermediate circuit (6) in the form of the intermediate circuit voltage (U.sub.Zk), and the measuring device (13) is designed to actuate an input short-circuit switch (S.sub.Boost) for short-circuiting the DC input (3) with the AC disconnector (8) open, as a result of which the intermediate circuit voltage (U.sub.Zk) can be applied to the DC input (3) in the reverse direction, and the measuring device (13) is configured to record measured voltages (U.sub.M1, U.sub.M2) with the switch (S.sub.iso) of the voltage divider (14) open and closed, and to determine the insulation resistance (R.sub.iso) from the measured values of the two measured voltages (U.sub.M1, U.sub.M2) recorded with the switch (S.sub.iso) of the voltage divider (14) open and closed.

A voltage potential measurement arrangement for measuring a voltage potential on a conductor in an encapsulated power switching device includes at least a portion of the conductor surrounded by a field control component, in particular a field control electrode, having a measuring electrode for capacitive coupling to the conductor. The measuring electrode is disposed outside of the field control component and the field control component is penetrated by at least one aperture at the height of the measuring electrode. A corresponding encapsulated power switching device is also provided.

A subscriber station for a serial bus system. The subscriber station encompasses: a communication control device for controlling communication with at least one further subscriber station of the bus system; a transmission/reception device for receiving a message from a bus of the bus system, which message was created by the communication control device or by the at least one further subscriber station of the bus system and is being transferred on the bus; an interference detection unit that is configured to detect interference in the context of transfer of the message on the bus; and an interference processing unit that is configured to evaluate the interference detected by the interference detection unit in terms of the nature and magnitude of the interference, and to adapt communication control by the communication control device to the result of the evaluation of the interference.

A circuit carrier is configured to be mounted to a battery system. The circuit carrier includes a circuit carrier board having a first region, a second region, and a third region. The first region is configured to receive a shunt resistor, the third region is configured to receive further electronic components, and the first region and the third region being separated from each other by the second region. The second region is a flexible connection between the first region and the third region and includes a spring-like structure formed from the circuit carrier board.

A power monitor includes a detecting circuit, a processing circuit, and a warning circuit. The detecting circuit detects a first abnormal condition of a primary side circuit and a second abnormal condition of a secondary side circuit. The processing circuit calculates a first class and a first occurring number of the first abnormal condition, and calculates a second class and a second occurring number of the second abnormal condition. The processing circuit determines whether the first occurring number is larger than a first predetermined number corresponding to the first class; if it is, the processing circuit outputs a first abnormal signal. The processing circuit determines whether the second occurring number is larger than a second predetermined number corresponding to the second class; if it is, the processing circuit outputs a second abnormal signal. The warning circuit outputs a warning signal according to the first or the second abnormal signal.

A data processing board according to an embodiment of the present disclosure includes a data processing module including at least one data processing board for automatically assigning an identifier according to the voltage value measured in the internal circuit and a communication board for transmitting and receiving signal to/from the data processing board, and a data processing system including the data processing module and a monitor collecting device for selecting and parallel-processing the data received from the data processing module.

A fault isolating device for use in a microgrid disconnected from a main power grid includes a voltage meter for detecting a voltage anomaly indicative of an electrical fault, a timer for establishing a time window that begins and ends a predetermined time after a voltage anomaly is detected, a switch that is opened at the start of the time window, and a microcontroller that determines whether to leave the switch open to isolate a faulted portion of the microgrid or to close the switch. A plurality of fault isolating devices can be distributed throughout a microgrid to isolate a faulted branch or faulted branches of an islanded microgrid without interfering with normal fuse operation when the microgrid is connected to the main power grid.

A sensor unit includes a current sensor that detects a current, a voltage sensor that detects a voltage, a ground fault sensor that detects a ground fault, and a common substrate on which the current sensor, the voltage sensor, and the ground fault sensor are mounted. In the sensor unit, for example, in a power supply circuit of a vehicle, the three sensors of the high voltage system can be integrated on the common substrate, so that an increase in the number of parts can be suppressed.

There is provided a laser welding method of joining a bus bar and an intermediate member by irradiating a laser beam on a surface of the intermediate member with the bus bar and the intermediate member being overlapped with each other. The laser welding method includes: a first welding step of forming a first welding line by moving the laser beam in a C shape from a welding start point to a welding intermediate point when viewed from a direction orthogonal to a surface of the intermediate member; and a second welding step of forming a second welding line continuous with the first welding line by moving the laser beam from the welding intermediate point to a welding end point located in a welding region formed inside the first welding line from the welding start point and the welding intermediate point.

A measuring circuit (100) is described, for the voltage of an electric machine comprising a first operational amplifier (20) having its non-inverting input (5) connected to a non-inverting input (10) of at least one second operational amplifier (30), and its output (7) feedback connected, through a resistance (R5), to the inverting input (6), the inverting input (6) of the first operational amplifier (20) being further connected through a resistance (R6) to a first phase (C) of the input current to an electric machine, the output (7) of the first operational amplifier (20) being connected, through a resistance (R8), to the inverting input (2) of a third operational amplifier (40) which has its non-inverting input (3) connected to a reference voltage (VREF), the output (7) of the first operational amplifier (20) being further connected to a first output (VC) of the circuit, which is at a voltage value equal to the voltage of a first phase of the electric machine to be measured, said third operational amplifier (40) having its output (1) feedback connected, through a capacitance (Cl), to the inverting input (2), the output (1) of the third operational amplifier (40) being further connected through a resistance (R10) to the non-inverting input (5) of the first operational amplifier (20) and to the non-inverting input (10} of the second operational amplifier (30); a system and a process for calibrating electric machines using such circuit (100) are further described.