Various embodiments of the teachings herein include a DC network comprising: an electrical conductor; a switching unit arranged at one end of the conductor to break the electrical connection via the conductor, the switching unit including a controllable power semiconductor connected in series in the current path of the conductor; wherein the conductor includes a first section and a second section starting from the switching unit with a connection point between the first section and the second section; a first overvoltage protection apparatus connected between the connecting point and a second pole of the DC network; and a second overvoltage protection apparatus connected between that end of the second section remote from the switching unit and the second pole. The overvoltage protection apparatuses each have a capacitor.

Provided is an arc suppression device including one or more current-limiting circuits provided in parallel with a circuit breaker that switches between feeding and shutoff of power from a power supply. The current-limiting circuit shuts off a current from the power supply when the power from the power supply is fed to a load through a circuit breaker. The current from the power supply is shut off when a voltage generated by a potential difference between contacts of the circuit breaker becomes a predetermined voltage or higher in a case where feeding of the power from the power supply to the load is shut off by the circuit breaker. The potential difference is generated upon shutoff.

In order to provide a DC interrupting device that does not easily cause erroneous melting of current-limiting fuses at normal times with no fault current, and that can also deliver good current-limiting performance at the time of occurrence of fault current, the DC interrupting device includes: a (k−1)th current path including a (k−1)th current-limiting fuse, where k is an integer of not less than two and not more than N, and N is an integer of not less than two; and a kth current path connected in parallel to the (k−1)th current path and including a kth current-limiting fuse. The inductance value of the inductance component of the kth current path is higher than the inductance value of the inductance component of the (k−1)th current path.

A transformer arrangement is provided. The transformer arrangement includes a transformer with a primary and a secondary winding and a chain link of switching blocks connected in series between one of the windings and a load, where the switching blocks comprise a first set of voltage contribution blocks and a second set of circuit breaker blocks, where the first set of voltage contribution blocks is configured to adjust a voltage output by the transformer with an offset voltage and the second set of circuit breaker blocks is configured to interrupt a current running through the chain link.

An AC switch that includes a semiconductor switch and a snubber circuit connected in parallel between a first terminal connected to an AC power supply via a circuit breaker and a second terminal connected to a load. The power converter is connected between a power storage device and the second terminal. The current detector detects a current flowing through the AC switch. When the AC power supply is normal, the controller turns on the semiconductor switch. When an open state of the circuit breaker is detected, the controller controls the power converter to supply a current having a phase opposite to that of the current detected by the current detector to flow through the semiconductor switch and supply the AC power to the load. The controller further turns off the semiconductor switch in response to that the amplitude of the current detected by the current detector is 0.

A switching device includes a number of line sections corresponding to a number of phases, each including a first and a second connection part, for connection to a connection phase of an electrical consumer. At least one controllable semiconductor switching element is provided per phase, wired between the first and second connection part. A bypass unit includes one controllable electromechanical switching element with a low on-resistance per phase. The controllable electromechanical switching element is wired, in parallel with the controllable semiconductor switching element of this phase, between the first and second connection part. The first and second connection part of a respective phase are arranged adjacently on one side of the power module in spatial proximity in a direction of extent. A contact bridge, assigned to a respective phase, runs in the direction of extent in order to electrically connect the first and second connection part in the switched-on state.

Within a direct current hybrid circuit breaker (DC HCB), a commutation unit (CU) is provided in a semiconductor switch path in series with a semiconductor switch to facilitate opening the DC HCB. The semiconductor switch path is connected in parallel with a mechanical switch path that includes a mechanical switch. The CU is a controlled voltage source which applies a reverse biased voltage on the semiconductor switch path. The CU causes the current through the mechanical switch to ramp down while the current through the semiconductor switch ramps up to a supply current. The CU maintains the current through the mechanical switch to remain at a zero vale by compensating for the voltage drop across the semiconductor switch and the self-inductance of the semiconductor switch path. The mechanical switch can open without current and against no recovery voltage.

A mechanical switch dimming and speed regulation control system includes a double-contact mechanical switch including at least one alternating current live wire input end, and at least one group of normally closed contact and normally open contact mutually short-circuited with each other, a dimming and speed regulation controller including a signal collector and a dimming and speed regulation control circuit, and a controlled device, outputs of the normally closed and open contacts loop-connected with the dimming and speed regulation controller, the dimming and speed regulation controller loop-connected with the controlled device, the signal collector electrically connected with an output loop of the double-contact mechanical switch and the dimming and speed regulation control circuit, respectively; the dimming and speed regulation control circuit loop-connected with the controlled device. The present disclosure implements high-power dimming and speed regulation control of a single live wire by using the double-contact mechanical switch, and overcomes problems of power limitation of a conventional dimming and speed regulation switch and difficulty for an intelligent switch to implement dimming and speed regulation of the single live wire.

A point-on-wave relay device includes a first contact relay and a second contact relay in series with the first contact relay. A first state of the first contact relay in conjunction with a first state of the second contact relay causes a point-on-wave open operation and second state of the first contact relay in conjunction with a second state of the second contact relay causes a point-on-wave close operation.

Multi-port power adapters. At least one example is a method including: supplying a first bus voltage to a first device by way of a DC-DC converter coupled to a link voltage; supplying a second bus voltage to a second device by way of a second DC-DC converter coupled to the link voltage; converting an AC voltage to the link voltage by way of an AC-DC converter; selecting, by a shunt regulator, a setpoint for the link voltage based on the first bus voltage and the second bus voltage; and regulating the link voltage to the setpoint by the AC-DC converter.