Provided is a relay device that can switch conduction of a current flow path between power storage units on and off, and can suppress a decrease in the output of the power storage units if an abnormality occurs. A relay device includes: a conductive path between a first power storage unit and a second power storage unit, the conductive path serving as a path through which a current flows; a switch unit that is switched between an ON state in which a current can flow through the conductive path, and an OFF state in which the conductive path is in a predetermined no current flow state; a coil that is connected in series to MOSFETs constituting the switch unit, and has an inductance component; and a control unit configured to switch off the switch unit if a value detected by a current detection unit is a predetermined abnormal value.

Provided is a relay device that can switch conduction of a current flow path between power storage units on and off, and can suppress a decrease in the output of the power storage units if an abnormality occurs. A relay device includes: a conductive path between a first power storage unit and a second power storage unit, the conductive path serving as a path through which a current flows; a switch unit that is switched between an ON state in which a current can flow through the conductive path, and an OFF state in which the conductive path is in a predetermined no current flow state; a coil that is connected in series to MOSFETs constituting the switch unit, and has an inductance component; and a control unit configured to switch off the switch unit if a value detected by a current detection unit is a predetermined abnormal value.

The present disclosure relates to a wireless neutral current sensor (WNCS) for monitoring a neutral cable of a capacitor bank. The WNCS may include a power storage device that provides power to allow the WNCS to send a test signal to a capacitor bank controller (CBC) of the capacitor bank to confirm operation of the WNCS during commissioning. The WNCS may include processing and communication circuitry that, during operation, detects an electrical characteristic on the neutral cable. The processing and communication circuitry may provide a message indicating the electrical characteristic to the CBC.

The present disclosure relates to a wireless neutral current sensor (WNCS) for monitoring a neutral cable of a capacitor bank. The WNCS may include a power storage device that provides power to allow the WNCS to send a test signal to a capacitor bank controller (CBC) of the capacitor bank to confirm operation of the WNCS during commissioning. The WNCS may include processing and communication circuitry that, during operation, detects an electrical characteristic on the neutral cable. The processing and communication circuitry may provide a message indicating the electrical characteristic to the CBC.

A frequency converter includes a storage element for storing electrical energy and a detector connected to the storage element and including a pressure sensor and a temperature sensor. The detector detects a physical variable hi immediate vicinity of the storage element and provides a signal in accordance with an electrical resistance of the detector when a predefinable change over time of the physical variable is exceeded, with the electrical resistance representing an output of the detector. A housing encloses or substantially encloses the detector and the storage element. Communicating with the detector is an evaluation facility to detect the predefinable change over time of the physical variable. The evaluation facility and/or the detector is/are connected to a higher-level security system designed to decouple and/or to divert the electrical energy from the storage element when the predefinable change over time of the physical variable is exceeded.

An Uninterruptible Power Supply (UPS) system is provided which includes an input configured to receive input power, an output configured to provide output power to a load, power conversion circuitry coupled to the input and the output, a capacitor coupled to the power conversion circuitry, and a controller coupled to the power conversion circuitry. The controller is configured to determine a first value indicative of an equivalent series resistance of the capacitor, determine, based on the first value, if the capacitor satisfies at least one criterion, and execute, responsive to determining that the relative value satisfies the at least one criterion, one or more actions to address degradation of the capacitor.

An Uninterruptible Power Supply (UPS) system is provided which includes an input configured to receive input power, an output configured to provide output power to a load, power conversion circuitry coupled to the input and the output, a capacitor coupled to the power conversion circuitry, and a controller coupled to the power conversion circuitry. The controller is configured to determine a first value indicative of an equivalent series resistance of the capacitor, determine, based on the first value, if the capacitor satisfies at least one criterion, and execute, responsive to determining that the relative value satisfies the at least one criterion, one or more actions to address degradation of the capacitor.

A modular power flow control system having early detection and reporting of transmission line faults is described. The response time for closing a bypass switch and reporting the fault is less than 200 microseconds for hard faults, longer for soft faults. Reprogramming of distance relays is not required. Transmission line faults are characterized using a fault detection sensor suite, normally including at least a current sensor such as a current transformer and a rate of current change sensor such as a Rogowski coil, and in some embodiments, a temperature sensor. Other embodiments are disclosed.

An adaptive protection method for impedance of parallel capacitors comprises monitoring a terminal voltage and current of the capacitor; automatically calibrating the initial impedance of the capacitor when the capacitor is put into operation; calculating a real-time impedance of the capacitor during operation, dynamically updating the actual impedance of the capacitor periodically; comparing the real-time impedance of the capacitor with the actual impedance, updating the actual impedance if the relative value of the modulus of the real-time impedance change does not exceed the dynamic update limit threshold and the dynamic update reaches update period; generating an update failure alarm if the relative value of the modulus of the real-time impedance change exceeds the dynamic update limit threshold; generating a protection alarm if the relative value of the modulus of the real-time impedance change satisfies the protection alarm condition and the delay time is reached; and protecting the trip outlet if the relative value of the modulus of the real-time impedance change satisfies the protection trip condition and the delay time is reached. The protection method is applicable to various fault conditions of the capacitor and the capacitor bank, the set value is simple to calculate, the implementation is simple, and the sensitivity and reliability of the protection for capacitor are effectively improved.

An adaptive protection method for impedance of parallel capacitors comprises monitoring a terminal voltage and current of the capacitor; automatically calibrating the initial impedance of the capacitor when the capacitor is put into operation; calculating a real-time impedance of the capacitor during operation, dynamically updating the actual impedance of the capacitor periodically; comparing the real-time impedance of the capacitor with the actual impedance, updating the actual impedance if the relative value of the modulus of the real-time impedance change does not exceed the dynamic update limit threshold and the dynamic update reaches update period; generating an update failure alarm if the relative value of the modulus of the real-time impedance change exceeds the dynamic update limit threshold; generating a protection alarm if the relative value of the modulus of the real-time impedance change satisfies the protection alarm condition and the delay time is reached; and protecting the trip outlet if the relative value of the modulus of the real-time impedance change satisfies the protection trip condition and the delay time is reached. The protection method is applicable to various fault conditions of the capacitor and the capacitor bank, the set value is simple to calculate, the implementation is simple, and the sensitivity and reliability of the protection for capacitor are effectively improved.