An electric assembly includes a reverse conducting switching device and a rectifying device. The reverse conducting switching device includes transistor cells for desaturation configured to be, under reverse bias, turned on in a desaturation mode and to be turned off in a saturation mode. The rectifying device is electrically connected anti-parallel to the switching device. In a range of a diode forward current from half of a maximum rating diode current of the switching device to the maximum rating diode current, a diode I/V characteristic of the rectifying device shows a voltage drop across the rectifying device higher than a saturation I/V characteristic of the switching device with the transistor cells for desaturation turned off and lower than a desaturation I/V characteristic of the switching device with the transistor cells for desaturation turned on.

A device (2) for the on-demand commutation of an electrical current from a first line branch (14, 3; 36) to another, second line branch (4; 41; 71) is created, which has a number of power semiconductor switching elements (7; 47; 53), which are arranged in series and/or parallel to one another in the second line branch (4; 41; 71), and a control unit (18; 51) for controlling the number of power semiconductor switching elements (7; 47; 53). The control unit (18; 51) is adapted to apply to each of the number of power semiconductor switching elements (7; 47; 53) an increased control voltage (VGE) whose level is above the maximum permissible control voltage specified for continuous operation, in order to switch on or maintain the conduction of the number of power semiconductor switching elements and to cause an increased current flow through it, whose current rating is at least double the nominal operating current. The control unit (18; 51) is further adapted to switch off the number of power semiconductor switching elements after a respectively provided short switch-on duration by switching off the control voltage (VGE) again while they conduct an increased current flow. The device (2) can thus be designed for a higher power in operation, or, at a given operating power, the semiconductor area and size of the device (2) can be reduced.

A device (2) for the on-demand commutation of an electrical current from a first line branch (14, 3; 36) to another, second line branch (4; 41; 71) is created, which has a number of power semiconductor switching elements (7; 47; 53), which are arranged in series and/or parallel to one another in the second line branch (4; 41; 71), and a control unit (18; 51) for controlling the number of power semiconductor switching elements (7; 47; 53). The control unit (18; 51) is adapted to apply to each of the number of power semiconductor switching elements (7; 47; 53) an increased control voltage (VGE) whose level is above the maximum permissible control voltage specified for continuous operation, in order to switch on or maintain the conduction of the number of power semiconductor switching elements and to cause an increased current flow through it, whose current rating is at least double the nominal operating current. The control unit (18; 51) is further adapted to switch off the number of power semiconductor switching elements after a respectively provided short switch-on duration by switching off the control voltage (VGE) again while they conduct an increased current flow. The device (2) can thus be designed for a higher power in operation, or, at a given operating power, the semiconductor area and size of the device (2) can be reduced.

The invention relates to an energizing circuit of at least one magnetizing coil of an operational brake, the energizing circuit being configured for energizing the magnetizing coil, which energizing circuit comprises a rectifying bridge connected to the supply network, the output terminals of the rectifying bridge being connectable/connected to the input points of the magnetizing coil,

characterized in that the energizing circuit comprises at least one reduced voltage circuit or external DC supply, whose outputs are connectable via to the to the input points of the magnetizing coil via a controllable operation switch of the energizing circuit. The patent application also comprises claims for a passenger conveyor and for a method.

An AC-to-AC modular multilevel converter (MMC) is configured to be connected between a three-phase AC system and a single-phase AC system. The MMC includes a number of converter arms connected in a ring to allow a circulating current to be circulated in the ring through each of the converter arms. Each converter arm includes series-connected converter cells. Phase terminals are arranged in the ring between the converter arms such that each of the converter arms is separated from neighboring converter arms by at least one of the phase terminals. The phase terminals include respective terminals for each of a first phase, a second phase and a third phase of the three-phase AC system and respective terminals for each of a positive conductor and a negative conductor of the single-phase AC system.

An AC-to-AC modular multilevel converter (MMC) is configured to be connected between a three-phase AC system and a single-phase AC system. The MMC includes a number of converter arms connected in a ring to allow a circulating current to be circulated in the ring through each of the converter arms. Each converter arm includes series-connected converter cells. Phase terminals are arranged in the ring between the converter arms such that each of the converter arms is separated from neighboring converter arms by at least one of the phase terminals. The phase terminals include respective terminals for each of a first phase, a second phase and a third phase of the three-phase AC system and respective terminals for each of a positive conductor and a negative conductor of the single-phase AC system.

A front stage circuit of a transformer includes a switch series unit, capacitors, and a ground electrical path. The switch series unit, connected in parallel to a power supply, includes odd-numbered/even-numbered switches configured to be alternately turned ON. Assuming that mutual connection points of the switches and points at both ends of the switch series unit are m nodes in total, and one of the points at the both ends is a ground node, the capacitors are provided on at least one of a first electrical path that combines odd nodes and leads them to a first output port, and a second electrical path that combines even nodes and leads them to a second output port, and the capacitors are present to correspond to (m−1) nodes excluding the ground node. The ground electrical path connects the ground node directly to the first output port without an interposed capacitor.

Voltage converter circuits including a first and second branch. The first branch is coupled between a first DC terminal and a second DC terminal and includes a first and second winding around a magnetic core. The first and second winding are coupled to an AC terminal via a common node. The second branch is coupled in parallel to the first branch between the first and second DC terminals and includes a third winding around the magnetic core. The third winding is coupled to the AC terminal such that the first and second branches convert a first voltage into a second voltage. The first, second and third windings are configured to cause magnetic flux generated by a differential mode (DM) component of a first current in the first branch and magnetic flux generated by the DM component of a second current in the second branch to enhance with each other.

Voltage converter circuits including a first and second branch. The first branch is coupled between a first DC terminal and a second DC terminal and includes a first and second winding around a magnetic core. The first and second winding are coupled to an AC terminal via a common node. The second branch is coupled in parallel to the first branch between the first and second DC terminals and includes a third winding around the magnetic core. The third winding is coupled to the AC terminal such that the first and second branches convert a first voltage into a second voltage. The first, second and third windings are configured to cause magnetic flux generated by a differential mode (DM) component of a first current in the first branch and magnetic flux generated by the DM component of a second current in the second branch to enhance with each other.

A pre-charge control method for a hybrid multilevel power converter comprises steps of: (a) controlling access of the current-limiting resistor unit, limiting current from the AC power via the current-limiting resistor unit, and outputting the current; (b) controlling the second capacitor unit to bypass, and charging the first capacitor unit; (c) controlling the access of the second capacitor unit when the first capacitor unit is charged to a third preset voltage, and charging the first and second capacitor units at the same time; (d) controlling the first capacitor unit to bypass when the second capacitor unit is charged to a fourth preset voltage, or the first capacitor unit is charged to a first preset voltage, and charging the second capacitor unit; and (e) controlling the access of the first capacitor units and the current-limiting resistor unit to bypass when the second capacitor unit is charged to a second preset voltage.