A capacitor bank which has a plurality of capacitor units, in which each capacitor has a plurality of electrical capacitor elements, and the capacitor units are divided into a plurality of groups of capacitor units. The arrangement has a plurality of group monitoring units, with one of the group monitoring units associated with each group of capacitor units. At least one of the group monitoring units is configured so that it monitors the respective group of capacitor units for a failure of a capacitor element in one of the capacitor units of the group and, when such a failure of a capacitor element is detected, transmits data which describe this failure of the capacitor element to a monitoring receiver.

A capacitor bank which has a plurality of capacitor units, in which each capacitor has a plurality of electrical capacitor elements, and the capacitor units are divided into a plurality of groups of capacitor units. The arrangement has a plurality of group monitoring units, with one of the group monitoring units associated with each group of capacitor units. At least one of the group monitoring units is configured so that it monitors the respective group of capacitor units for a failure of a capacitor element in one of the capacitor units of the group and, when such a failure of a capacitor element is detected, transmits data which describe this failure of the capacitor element to a monitoring receiver.

Methods and systems include identifying an abnormal condition in a PFC circuit comprising an input configured to be coupled to a 3-phase power source and to receive input 3-phase power from the 3-phase power source, a bus having a plurality of bus lines, each bus line configured to be coupled to the input and to carry one phase of the input 3-phase power, a PFC leg including a contactor configured to selectively couple a capacitor bank included in the PFC leg to the bus. In response to identifying the abnormal condition, the contactor is controlled to decouple the capacitor bank from the bus, and after a reset button has been activated, the contactor is recoupled to the capacitor bank to resume operating the PFC leg to provide power factor correction to the input 3-phase power.

Methods and systems include identifying an abnormal condition in a PFC circuit comprising an input configured to be coupled to a 3-phase power source and to receive input 3-phase power from the 3-phase power source, a bus having a plurality of bus lines, each bus line configured to be coupled to the input and to carry one phase of the input 3-phase power, a PFC leg including a contactor configured to selectively couple a capacitor bank included in the PFC leg to the bus. In response to identifying the abnormal condition, the contactor is controlled to decouple the capacitor bank from the bus, and after a reset button has been activated, the contactor is recoupled to the capacitor bank to resume operating the PFC leg to provide power factor correction to the input 3-phase power.

A capacitive power supply circuit including, between first and second terminals of application of an AC input voltage-UN, a distributed capacitive structure including a plurality of elementary capacitive units, each including a current limiter series-connected with a capacitor between first and second terminals of the unit and a voltage limiter connected in parallel with the capacitor, the elementary capacitive units being series-coupled by their first and second terminals.

One or more embodiments relate to a control circuit for an input filter circuit in a switch mode power supply comprising a power switch and a switch controller to control the power switch to provide a regulated output voltage and current to a load. The control circuit, also referred to as a filter control circuit, can be used to detect a high voltage surge at its input and disconnect a capacitor in the input filter circuit from an input return, thereby protecting the input filter capacitor and the SMPS from damage. According to certain aspects, the control circuit can be integrated with the switch controller. Additionally, the control circuit can provide power to the switch controller at start-up.

A power conversion apparatus and a short circuit protection circuit and method of capacitor thereof are provided. A rectifier circuit rectifies an AC signal into a DC signal. An electrical energy storage circuit is coupled to the rectifier circuit, and the electrical energy storage circuit includes a plurality of capacitors connected in series. A detection circuit is coupled to the electrical energy storage circuit to detect cross voltages of the capacitors. A control circuit is coupled to the rectifier circuit and the detection circuit. When the cross voltage of any of the plurality of capacitors is greater than a preset voltage, the rectifier circuit is disabled by the control circuit.

A method for online limit early-warning to a shunt capacitor bank, and the method comprises: performing harmonic monitoring to the shunt capacitor bank; obtaining a measured voltage and a measured current, based on raw data obtained by the harmonic monitoring; obtaining a first parameter representing a ratio of the measured voltage to a rated voltage and a second parameter representing a ratio of the measured current to a rated current, based on the measured voltage and the measured current; obtaining a relation between an impedance correlation quantity of the shunt capacitor bank and a background harmonic voltage ratio, based on the first parameter, the second parameter, and an obtained series reactance ratio of a detected capacitor circuit; and performing online limit early-warning to the shunt capacitor bank, based on the relation. The present invention also discloses a device for online limit early-warning to a shunt capacitor bank.

A method for online limit early-warning to a shunt capacitor bank, and the method comprises: performing harmonic monitoring to the shunt capacitor bank; obtaining a measured voltage and a measured current, based on raw data obtained by the harmonic monitoring; obtaining a first parameter representing a ratio of the measured voltage to a rated voltage and a second parameter representing a ratio of the measured current to a rated current, based on the measured voltage and the measured current; obtaining a relation between an impedance correlation quantity of the shunt capacitor bank and a background harmonic voltage ratio, based on the first parameter, the second parameter, and an obtained series reactance ratio of a detected capacitor circuit; and performing online limit early-warning to the shunt capacitor bank, based on the relation. The present invention also discloses a device for online limit early-warning to a shunt capacitor bank.

Flexible AC transmission system (FACTS) enabling distributed controls is a requirement for power transmission and distribution, to improve line balancing and distribution efficiency. These FACTS devices are electronic circuits that vary in the type of services they provide. All FACTS devices have internal circuitry to handle fault currents. Most of these circuits are unique in design for each manufacturer, which make these FACTS devices non-modular, non-interchangeable, expensive and heavy. One of the most versatile FACTS device is the static synchronous series compensator (SSSC), which is used to inject impedance into the transmission lines to change the power flow characteristics. The addition of integrated fault current handling circuitry makes the SSSC and similar FACTS devices unwieldy, heavy, and not a viable solution for distributed control. What is disclosed are modifications to FACTS devices that move the fault current protection external to the FACTS device and make them modular and re-usable.