Abstract: The teachings herein include DC/DC converter systems. An example system may include: a full-bridge converter and a switch control circuit. The converter includes a primary side and a secondary side full-bridge circuit and a transformer. AC nodes of the primary side are connected to a primary side of the transformer and AC nodes of the secondary side to a secondary side of the transformer. The switch control circuit: controls the primary side and the secondary side circuits in a normal operating phase including modulation of an input voltage by the primary side full-bridge circuit transferring power via the transformer, control the primary side and the secondary side in a free-wheeling phase during which they are both deactivated to reduce the transformer's magnetization current; and control the full-bridge circuits to switch between the normal operating phase and the free-wheeling phase alternately.

Abstract: Some embodiments of the teachings herein include a DC/DC converter system. The system may include: a full-bridge converter and a switch control circuit. The converter includes a primary side and a secondary side full-bridge circuit and a transformer. AC nodes of the primary side are connected to a primary side of the transformer and AC nodes of the secondary side to a secondary side of the transformer. The switch control circuit: controls the primary side and the secondary side circuits in a normal operating phase including modulation of an input voltage by the primary side full-bridge circuit transferring power via the transformer, control the primary side and the secondary side in a free-wheeling phase during which they are both deactivated to reduce the transformer’s magnetization current; and control the full-bridge circuits to switch between the normal operating phase and the free-wheeling phase alternately.

Abstract: In a method for controlling a cycloconverter having six converter branches connected in series, in which converter branches electrical energy stores are provided, the energy transfer from a first three-line network into a second three-line network or vice versa is controlled according to energy demand criteria, energy supply criteria, and/or reactive power criteria for converter operation control. The amount of electrical energy stored in each converter branch or an electrical variable that characterizes the amount of electrical energy is controlled to a predetermined setpoint range for energy converter control.

Abstract: A transformerless cycloconverter for connecting a first three-conductor system to a second three-conductor system by bridge modules with electronic semiconductor switches has precisely six bridge modules or series circuits thereof with a first bridge module or series circuit connected to the first conductors of the first and second systems, a second bridge module or series circuit connected to the second and first conductors of the first and second systems, a third bridge module or series circuit connected to the second conductors of the first and second systems, a fourth bridge module or series circuit connected to the third and second conductors of the first and second systems, a fifth bridge module or series circuit connected to the third conductors of the first and second systems, and a sixth bridge module or series circuit connected to the first and third conductors of the first and second systems.

Abstract: A cycloconverter has six converter branches connected in series, and said converter branches have energy stores. A method for controlling the cycloconverter connecting a first three-line network to a second three-line network includes controlling the converter operation by controlling energy transfer from the first three-line network to the second three-line network or vice versa according to energy demand criteria, energy supply criteria, and/or reactive power criteria, and by controlling the amount of electrical energy stored in each converter or by controlling an electrical variable that characterizes the amount of electrical energy to a specified target range. The invention further relates to an electronic control device for such a cycloconverter, and to a computer program for carrying out the method.

Abstract: The invention relates to a transformerless cycloconverter for connecting a first three-conductor grid (50), in particular a three-phase grid, to a second three-conductor grid (51), in particular a three-phase grid, by means of bridge modules comprising electronic semiconductor circuits (5, 6, 7, 8), having the following characteristics: a) a first bridge module (1) or a first series circuit (52) of bridge modules (1) is connected to a first conductor (500) of the first power supply grid (50) and to a first conductor (510) of the second power supply grid (51), b) a on one side and to a first conductor (510) of the second power supply grid (51) on the other side, b) a second bridge module (1) or a second series circuit (53) of bridge modules (1) is connected to a second conductor (501) of the first power supply grid (50) and to the on one side and to the first conductor (510) of the second power supply grid (50), c) a conductor (510) of the second power supply grid (51) on the other side, c) a third bridge modu