Described methods and systems provide in-situ leakage current testing of battery cells in battery packs even while these packs operate. Specifically, an external electrical current is discontinued through a tested battery cell using a node controller, to which the tested battery cell is independently connected. Changes in the open circuit voltage (OCV) are then detected by the node controller for a set period time. Any voltage change, associated with taking the tested cell offline, is compensated by one or more other cells in the battery pack. The overall pack current and voltage remains substantially unchanged (based on the application demands), while the in-situ leakage current testing is initiated, performed, and/or completed. The OCV changes are then used to determine the leakage current of the tested cell and, in some examples, to determine the state of health of this cell and/or adjust the operating parameters of this cell.

A diagnostic device includes electrical connectors, load, power supply, switching circuitry, sensors, and processor. The connectors include first and second sets of terminals for connecting to the conductors of a branch circuit in an upstream and downstream direction, respectively, at an outlet location along the circuit. The switching circuitry can isolate the upstream and downstream sections of the circuit from the outlet location, and selectively connect or disconnect the power supply or the load to the upstream or downstream section. The sensors measure electrical characteristics on the conductors of the circuit to monitor load currents, such as on power, neutral and ground lines, of the upstream and downstream circuit sections. The processor controls the switching circuitry, and obtains diagnostic information corresponding to the monitored load currents on the upstream and downstream sections of the branch circuit, from the measurements performed by the sensors.

A method for abnormality detection in an energy unit includes passively detecting an abnormality in an energy unit by detecting electromagnetic radiation generated by the abnormality, the energy unit comprising at least one of an electrical energy unit and an electrochemical energy unit. A method for detecting an abnormality in an energy unit includes (a) applying a signal to the energy unit, (b) performing a plurality of measurements, at a respective plurality of different locations within the energy unit, of a response of the energy unit to the signal, and (c) processing the plurality of measurements to identify the abnormality.

An electric power conversion apparatus includes: an electric power conversion circuit that allows a DC terminal to be connected to a DC power source via a DC bus line, and performs at least one of converting DC power of the DC power source into AC power to output, or converting AC power into DC power to output; a DC switch turned on when the electric power conversion circuit performs electric power conversion; an AC switch provided on a side of the AC terminal, and turned on when the electric power conversion circuit performs the electric power conversion; a DC voltmeter that measures a potential at a predetermined portion, on a side of the DC terminal; a ground connection portion that connects the DC bus line and ground potential; and a control circuit connected to the electric power conversion circuit, the DC switch, the AC switch, and the DC voltmeter.

An electric power conversion apparatus includes: an electric power conversion circuit that allows a DC terminal to be connected to a DC power source via a DC bus line, and performs at least one of converting DC power of the DC power source into AC power to output, or converting AC power into DC power to output; a DC switch turned on when the electric power conversion circuit performs electric power conversion; an AC switch provided on a side of the AC terminal, and turned on when the electric power conversion circuit performs the electric power conversion; a DC voltmeter that measures a potential at a predetermined portion, on a side of the DC terminal; a ground connection portion that connects the DC bus line and ground potential; and a control circuit connected to the electric power conversion circuit, the DC switch, the AC switch, and the DC voltmeter.

Photovoltaic array performance monitoring systems and methods are described herein. One embodiment of a photovoltaic array monitoring system according to the present disclosure can include a reference photovoltaic panel and an ambient photovoltaic panel, as well as a rechargeable power source. The monitoring system can further include an electrical unit configured to charge the rechargeable power source using energy from one or both of the reference photovoltaic panel and the ambient photovoltaic panel. The monitoring system can also include a transmitter configured to transmit data from the reference photovoltaic panel and the ambient photovoltaic panel. Methods and full-size solar systems utilizing monitoring systems are also described.

A vacuum pump includes a control unit that monitors and controls a motor and a magnetic bearing, each being stored in a pump body. A temperature-adjustment function unit measures a temperature of the pump body by at least one temperature sensor disposed in the pump body and controls at least one heater or solenoid controlled valve based on the temperature. The temperature-adjustment function unit includes a first terminal capable of connecting or disconnecting the temperature sensor and a second terminal capable of connecting or disconnecting one of the heater and the solenoid controlled valve. A self-diagnosis unit capable of conducting a self-diagnosis of whether an input signal to the first terminal has been normally inputted or whether the signal has been normally outputted from the second terminal.

A vacuum pump includes a control unit that monitors and controls a motor and a magnetic bearing, each being stored in a pump body. A temperature-adjustment function unit measures a temperature of the pump body by at least one temperature sensor disposed in the pump body and controls at least one heater or solenoid controlled valve based on the temperature. The temperature-adjustment function unit includes a first terminal capable of connecting or disconnecting the temperature sensor and a second terminal capable of connecting or disconnecting one of the heater and the solenoid controlled valve. A self-diagnosis unit capable of conducting a self-diagnosis of whether an input signal to the first terminal has been normally inputted or whether the signal has been normally outputted from the second terminal.

Disclosed is a device for checking withstand voltage of a connector-coupled cable. The device comprises: a pair of electrode boxes; and a control block configured to apply a start signal to a test instrument, which outputs a preset high voltage, according to an electrical state detected in each electrode box that includes: a housing whose a part of a front side is open; a conductive electrode plate mounted on an inner front side of the housing in such a way that it is rotatable around its top end; and a detection unit, mounted inside the housing with a predetermined gap from the electrode plate, to detect whether the electrode plate is rotated due to push on a lower part of the electrode plate. The electrical state is an electrical state between both terminals of the detection unit, and the preset high voltage is applied between both electrode plates.

Disclosed is a device for checking withstand voltage of a connector-coupled cable. The device comprises: a pair of electrode boxes; and a control block configured to apply a start signal to a test instrument, which outputs a preset high voltage, according to an electrical state detected in each electrode box that includes: a housing whose a part of a front side is open; a conductive electrode plate mounted on an inner front side of the housing in such a way that it is rotatable around its top end; and a detection unit, mounted inside the housing with a predetermined gap from the electrode plate, to detect whether the electrode plate is rotated due to push on a lower part of the electrode plate. The electrical state is an electrical state between both terminals of the detection unit, and the preset high voltage is applied between both electrode plates.