There is provided a power conditioning circuit including positive and negative power input nodes. An inductor includes a first terminal connected to a positive power input node and a second terminal connected to a positive power output node, the inductor allowing the voltage at the positive power output node to be modulated by data that is sent through a communication interface. A first node is present between the second terminal of the inductor and the positive power output node, and a clamping circuit is connected at the first node to a second node. The clamping circuit is configured to clamp a voltage increase across the inductor to less than a maximum increase. The second node is configured to be continuously held at a voltage higher than the voltage of the first terminal of the inductor.

A switch element is arranged between an input terminal and an output terminal. A signal from the input terminal is distributed by a capacitative element and supplied to the cathode side of a diode. An inductor is connected to the cathode side of the diode, and a smoothing circuit including a capacitative element and a resistor is connected to the anode side. The switch element has a control terminal connected to the anode of the diode, and turns off a path between the input terminal and the output terminal when a voltage is applied to the control terminal.

A leakage current protection system includes a current transformer disposed about current-carrying conductors that extend from first ends to second ends. The first ends are coupled to load receptacles. The current transformer detects an aggregate differential current between the conductors. Each of a plurality of circuit breakers is coupled to the second ends of the conductors that are coupled to a corresponding one of the load receptacles. Each circuit breaker is coupled to a source of electrical power. A differential current monitor coupled to the current transformer generates a signal when the aggregate differential current exceeds a threshold current. Each of a plurality of shunt-trips coupled to the differential current monitor receives the signal. Each of the shunt-trips opens a corresponding one of the circuit breakers when the signal is received so that all of the circuit breakers are opened simultaneously.

In order to achieve a universal, flexible and highly integrated operating device for driving various lamps, ensuring the protection of the entire operating device and of the appliances connected thereto by means of staggered protective measures at both the input and the output, starting from the preamble of claim 1, a first branch for connecting a lamp to a first of the interface circuits (SS1) and a second branch for connecting at least one communication module to a second of the interface circuits (SS2) are connected to the coarse protection circuit (G) which short-circuits an overvoltage of the mains voltage occurring at the input of the operating device. In the first branch, a line filter (NF) is connected to the coarse protection circuit (G) and a clamp circuit (K) consisting of the fine protection circuit (F) and of a first energy absorber (E1) is connected to the line filter (NF). When the residual pulse voltage is too high, the fine protection circuit (F) activates the first energy absorber (E1), the overvoltage pulse is short-circuited and the short-circuit is deactivated again when the mains voltage reaches the next zero crossing. A second energy absorber (E2) which, when it is switched on, limits the current with the aid of a temperature-dependent resistor (NTC), is connected to the first energy absorber (E1). Moreover, the first interface circuit (SS1) comprises a protection circuit (ÜS) against overvoltage and overcurrent, and an intermediate protection circuit (M) consisting of a transmitter (Ü) and of a first fine protection circuit (F1) is connected to the coarse protection circuit (G) in the second branch. A filter (FK) for separating communication signals fed in parallel into the power supply grid is connected to the first fine protection circuit (F) and a second fine protection circuit (F2) is connected to this filter (FK). In order to protect the second interface circuit (SS2) of the operating device from overvoltage and overcurrent coming from the communication module and acting upon the operating device, the second interface circuit (SS2) comprises a protection circuit (ÜS) against overvoltage and overcurrent. The invention is used in the field of protection systems against overvoltage.

A solid-state circuit breaker and breaking method are disclosed. In an embodiment, the solid-state circuit breaker includes a semiconductor switch; a controller, connected to the semiconductor switch; and an energy absorber, connected in parallel with the semiconductor switch. The controller is configured to obtain an equivalent inductance of a circuit of the solid-state circuit breaker upon a fault occurring in a line. Further, upon the equivalent inductance being greater than an inductance estimated value, the controller is configured to set a second current fault threshold. Finally, upon a fault current of the line reaching the second current fault threshold, the semiconductor switch is controlled to execute a closing operation.

A fast-operating AC fault current limiter, to limit the fault current let through to downstream equipment during short circuit or low-impedance faults, comprises a series inductor to limit current rise time, a current sensor to sense the instantaneous current, a series AC semiconductor switch to interrupt current flow when it exceeds the maximum desired fault current, and a shunt AC semiconductor switch to catch inductor flyback voltage when the series semiconductor switch is opened. Each of the series and the shunt AC switches comprises two back-to-back MOSFETs. Inventive control of timing of the individual MOSFETs obviates the need for exact simultaneous timing of opening the series switch and closing the shunt switch, which is otherwise required to avoid short circuits.

There is described a device for controlling an amount of current within a power distribution network by manipulating the amount of magnetic flux in the device and thus the impedance experienced by the power distribution network across the device. This is achieved by winding a plurality of coils about a magnetically permeable core and by providing the device with a magnetically permeable bridge element that is movable between a fully-open position at which the net magnetic flux generated in the core by alternating currents in each coil is zero, and a fully-closed position at which a net magnetic flux is present in the core.

A current sinking arrangement is provided that comprises a current sinking arrangement for connection to three phases of an AC grid, operable for reduction of short circuit fault currents in the AC grid, the current diverting arrangement comprising first, second and third phase arrangements, each including first and second grid terminals and a current diversion branch having a first impedance and a first switch and connected to a common floating conductor. On reception of a signal indicating a fault, which requires fault current reduction, a switching arrangement is arranged to make the first switches conducting so as to divert a portion of the fault current away from the AC grid fault location to the common floating conductor.

There is provided a power conditioning circuit including positive and negative power input nodes. An inductor includes a first terminal connected to a positive power input node and a second terminal connected to a positive power output node, the inductor allowing the voltage at the positive power output node to be modulated by data that is sent through a communication interface. A first node is present between the second terminal of the inductor and the positive power output node, and a clamping circuit is connected at the first node to a second node. The clamping circuit is configured to clamp a voltage increase across the inductor to less than a maximum increase. The second node is configured to be continuously held at a voltage higher than the voltage of the first terminal of the inductor.

A switch element is arranged between an input terminal and an output terminal. A signal from the input terminal is distributed by a capacitative element and supplied to the cathode side of a diode. An inductor is connected to the cathode side of the diode, and a smoothing circuit including a capacitative element and a resistor is connected to the anode side. The switch element has a control terminal connected to the anode of the diode, and turns off a path between the input terminal and the output terminal when a voltage is applied to the control terminal.