A mechanical cut-off apparatus of a high-voltage electric circuit includes: in a main electrical path a main mechanical switch; in a secondary electrical path, a secondary mechanical switch; a mechanical control configured such that, the secondary mechanical switch is brought to its mechanically open state after the main mechanical switch has been brought to its mechanically open state; the apparatus includes a transition dipole comprising a capacitance, the transition dipole arranged in series with the pair of secondary electrical contacts in the secondary electrical path, and in that the apparatus includes a controlled switch which, in an electrically closed state, creates inside the mechanical cut-off apparatus a bypass that short-circuits the capacitance of the transition dipole.

A charging protection and regulation device includes a matrix of Positive Temperature Coefficient (PTC) devices having multiple legs each including one or more PTC devices, a matrix of diodes having multiple legs and multiple types of diodes having different voltage drops, and a matrix of resistors having multiple legs each including a current limiting resistor. Each PTC device is thermally coupled to an ambient environment using a different amount of thermal coupling. Respective legs of the matrix of PTC devices, matrix of diodes, and matrix of resistors are electrically coupled together, and coupled to one or more electron storage devices. During conditions of overload or circuit fault, the PTC devices act as high resistance circuit interrupters. During conditions of light loading between input and output terminals, the different voltage drops across the diodes provide voltage regulation/current regulation such that a specified charge voltage is provided to electron storage devices.

A charging protection and regulation device includes a matrix of Positive Temperature Coefficient (PTC) devices having multiple legs each including one or more PTC devices, a matrix of diodes having multiple legs and multiple types of diodes having different voltage drops, and a matrix of resistors having multiple legs each including a current limiting resistor. Each PTC device is thermally coupled to an ambient environment using a different amount of thermal coupling. Respective legs of the matrix of PTC devices, matrix of diodes, and matrix of resistors are electrically coupled together, and coupled to one or more electron storage devices. During conditions of overload or circuit fault, the PTC devices act as high resistance circuit interrupters. During conditions of light loading between input and output terminals, the different voltage drops across the diodes provide voltage regulation/current regulation such that a specified charge voltage is provided to electron storage devices.

An electrical protection unit A including a main conductor and, for each main conductor, a current limiter device connected in series with the main conductor to limit the current when a current or temperature threshold is exceeded, the limiter device including an element made of a material having a positive temperature coefficient, called PTC, and being capable of controlling a device for tripping the mechanism M for opening the contacts of the protection unit D, to cause the opening of the contacts of the unit when the threshold is exceeded leading to a change of state of the element between a low resistance state and a high resistance state. The PTC element includes the trip device, in such a way that this element itself provides the functions of fault current limitation and of tripping the mechanism for opening the contacts.

A DC high-voltage electrical installation comprises a switching device for switching an electric current in the main circuit, and a method for controlling the closure of a switching device in such an installation. The installation includes a controlled variable resistor system making it possible to modify the resistance value of the resistor system seen by the current flowing through the main electrical circuit. The resistance value takes at least three distinct values: high, a lower value, and at least one nonzero intermediate value comprised between the high value and the low value. The installation includes a coordination device making it possible to control switching times of the resistance values of the resistor system.

An electrical protection unit A including a main conductor and, for each main conductor, a current limiter device connected in series with the main conductor to limit the current when a current or temperature threshold is exceeded, the limiter device including an element made of a material having a positive temperature coefficient, called PTC, and being capable of controlling a device for tripping the mechanism M for opening the contacts of the protection unit D, to cause the opening of the contacts of the unit when the threshold is exceeded leading to a change of state of the element between a low resistance state and a high resistance state. The PTC element includes the trip device, in such a way that this element itself provides the functions of fault current limitation and of tripping the mechanism for opening the contacts.

A switching device includes: a first contact; a second contact; and a fault detection circuit. The second contact includes a fixed contactor and a movable contactor. When the second contact is energized due to an operation of opening the first contact, the movable contact is separated from the fixed contact by an electromagnetic force generated by a flow of currents in opposite directions through the pair of current-carrying electrodes, and a discharge switch is formed between the movable contact and the fixed contact that are separated. The switching device further includes: a first arc runner electrically connected to the fixed contactor for driving, by an electromagnetic force, arc discharge that occurs when the second contact is opened; and a second arc runner electrically connected to the movable contactor.

The disclosure relates to a circuit arrangement for suppressing an arc occurring during a switching process, wherein a current bypass path comprises a PTC resistor connected in series with a fuse. The current bypass path is provided in parallel with a switch. The disclosure also relates to a photovoltaic power plant with a photovoltaic generator which is connected to an inverter via DC lines. In this arrangement, such a circuit arrangement is arranged in at least one of the DC lines.