Provided is a collected current monitoring device enabling an analysis of collected current in each current collector while allowing a reduced equipment cost. The collected current monitoring device of the present disclosure is installed in a railroad vehicle including current collectors, main transformers, and main converters. The collected current monitoring device includes: a supply current sensor configured to measure a current supplied to a freely-selected one of the main transformers, at least one current-sensor-between-current-collectors disposed in each communication path connecting two adjacent ones of the current collectors and configured to measure a current flowing in the communication path, and a processor configured to calculate a current flowing in each of the current collectors based on the current measured by the supply current sensor and the current measured by the at least one current-sensor-between-current-collectors, and on a distribution ratio of the currents supplied to the main transformers.

Systems and methods are described for monitoring a high voltage electrical system in a vehicle. An interface circuit is configured to provide isolation between a high voltage component of the vehicle and a control module. The interface circuit comprises a high voltage constant current source, a voltage threshold detector and an electrical isolation circuit. The high voltage constant current source is configured to receive an input at a first voltage from the high voltage component. The voltage threshold detector is configured to receive an output from the high voltage constant current source and to output a signal to indicate whether the voltage of the high voltage component is at, or below, a desired voltage. The electrical isolation circuit is configured to receive the output signal from the voltage threshold detector, decouple the output signal from the high voltage component and, in response to receiving the output signal from the voltage threshold detector, output a signal at a second voltage to the control module.

The invention provides a detection circuit for detecting light-off modes performed by a silicon-controlled dimmer which comprises a voltage detection circuit receiving an output signal and generating a voltage detection signal according to the output signal, and a delay circuit connected to the voltage detection circuit, receiving the voltage detection signal, and delaying the voltage detection signal in order to output a detection signal. The invention detects the output signal through the voltage detection circuit, and delays the detected voltage detection signal to output the corresponding detection signal, and then the detection signal effectively distinguishes the light-off modes performed by the silicon-controlled dimmer to meet requirements of users.

Provided is a power conversion device with which it is possible to acquire a sign of a system stop before the system stops, and to minimize the nonworking time of the system. A power conversion device for converting DC voltage or AC voltage into AC voltage, the power conversion device being characterized by having an abnormality detection unit for detecting abnormalities in the power conversion device, a restart unit for stopping the power conversion device and automatically performing a restart when the abnormality detection unit has detected an abnormality, a restart recording unit for recording restart information of when the restart unit has restarted, and a sign diagnostic unit for inputting the restart information recorded by the restart recording unit and performing a sign diagnosis of the abnormality in the power conversion device on the basis of the restart information, the sign diagnostic unit performing the sign diagnosis on the basis of the number of restarts and outputting a sign diagnostic result.

Disclosed a quench protection device of a superconducting magnet system, including a superconducting coil set; the superconducting coil set comprises two superconducting coils (5) which are symmetrical arranged, and each of the two superconducting coils (5) is connected in parallel with a protection diode (4); the superconducting coils and the protection diode are connected with the power supply via a conductive wire; the superconducting coils set are connected in parallel with a quench protection unit (6), a change-over switch (3) is arranged on a circuit of the two superconducting coils, the protection diode, and the power supply, and the change-over switch (3) is connected with an external resistor via a conductive wire (2). The change-over switch of the quench protection device connects the superconducting coil and an external resistance, which realizes the quench protection of the superconducting coil.

An energization control device includes a voltage detection unit, a control portion, and an energization switching unit. The control portion to which the first detection signal and the second detection signal are input from the voltage detection unit is configured to output a first energization signal if the first detection signal is input and output a second energization signal if the second detection signal is input. The control portion is configured to obtain a correction value based on a difference between a first period in which the first detection signal is input to the control portion and a second period in which the second detection signal is input to the control portion and to correct a timing of switching between the first energization signal and the second energization signal with the correction value.

A system and method for programmably operating a DC load connected to a DC outlet. A power line communication (PLC) client at the outlet measures actual and desired DC voltage at the load. A remotely located DC power server is connected between a DC power source and the outlet. The power server has a PLC master in bidirectional feedback communication with the PLC client to determine the actual and desired DC voltage at the load. An adjustable DC voltage module at the power server is controlled by the PLC master to supply an adjustable DC voltage. The power server adjusts the DC voltage supplied by the voltage module to the load based on the bidirectional feedback communication between the PLC master and the PLC client.

A battery management apparatus can include a measuring unit configured to measure a voltage and a current of a battery cell, a calculating unit configured to determine an operating period of the battery cell based on the current of the battery cell, and calculate a comparison value for the battery cell by normalizing the voltage of the battery cell, and a diagnosing unit configured to diagnose a state of the battery cell by comparing a comparison value of the battery cell with a reference value.

There is provided a current detection circuit including: a current detection unit that detects a control current flowing between a control terminal of a semiconductor element of voltage-controlled type having a current detection terminal, and a drive circuit; an overcurrent detection unit that detects an overcurrent based on a result of comparing a sense voltage with a sense reference voltage, the sense voltage corresponding to a sense current flowing through the current detection terminal; and an adjustment unit that adjusts the sense reference voltage based on a detection result of the current detection unit.

There is provide a current detection circuit including: a current detection unit that detects a control current flowing between a control terminal of a semiconductor element of voltage-controlled type having a current detection terminal, and a drive circuit; an overcurrent detection unit that detects an overcurrent in response to a sense current exceeding an overcurrent threshold value, the sense current flowing through the current detection terminal; and an adjustment unit that sets, based on a detection result of the current detection unit, the overcurrent threshold value in a transient period during turn on and turn off of the semiconductor element to be higher than the overcurrent threshold value in a period other than the transient period.