Abstract: A step-up converter for stepping up an electrical input DC supply voltage to an electrical output DC supply voltage, including a voltage input having a positive and a negative input node, a voltage output having a positive and negative output node, a first and second output capacitor connected in series at the voltage output between the positive and negative output nodes and connected to one another via a center output node, and a first inductor connected between the positive and output nodes, a first switch, connected between the first inductor and the center output node, a second inductor connected between the negative output and negative input nodes, a second switch, connected between the center output node and the second inductor, and a total input capacitor, connected at the voltage input between the positive and negative input voltage nodes, the first and second inductors being inductively coupled to one another.

Abstract: A step-up converter for stepping up an electrical input DC supply voltage to an electrical output DC supply voltage, including a voltage input having a positive and a negative input node, a voltage output having a positive and negative output node, a first and second output capacitor connected in series at the voltage output between the positive and negative output nodes and connected to one another via a center output node, and a first inductor connected between the positive and output nodes, a first switch, connected between the first inductor and the center output node, a second inductor connected between the negative output and negative input nodes, a second switch, connected between the center output node and the second inductor, and a total input capacitor, connected at the voltage input between the positive and negative input voltage nodes, the first and second inductors being inductively coupled to one another.

Abstract: The invention relates to a power inverter circuit for coupling a power station to a power supply system. The invention addresses the problem to reduce the risk of damages to components of the power station and the power supply system in the course of coupling action by providing a power inverter circuit for adjusting symmetry of the AC voltage before coupling the inverter output to a load, comprising: first switching means for selectively connecting a positive voltage to the inverter circuit output, second switching means for selectively connecting a negative voltage to the inverter output, and ohmic resistance means coupled in parallel to the inverter output, a controller for selectively switching the first and second switching means with a switching frequency to produce an AC voltage from the positive and negative voltage, wherein the controller is adapted to alter the duty ratio of the switching frequency to adjust the symmetry of the AC voltage produced by the inverter.

Abstract: The present invention provides an inverter or other electronically controlled power source for transforming electrical energy into electrical energy of predetermined voltage and/or current comprising: an inner housing for housing the main circuitry of the inverter, a cover connected to the inner housing, covering at least part of the inner housing, defining at least one cover channel between the inner housing and the cover for air to flow through that channel for cooling of the inverter, whereby the cover channel is adapted to facilitate natural convection of the air. The present invention further proposes an inverter according to any of the preceding claims, additionally comprising at least one ventilator to enhance an air flow through the channel. According to the invention the cooling properties of an inverter are to be improved.

Abstract: The invention relates to a power inverter circuit for coupling a power station to a power supply system. The invention addresses the problem to reduce the risk of damages to components of the power station and the power supply system in the course of coupling action by providing a power inverter circuit for adjusting symmetry of the AC voltage before coupling the inverter output to a load, comprising: first switching means for selectively connecting a positive voltage to the inverter circuit output, second switching means for selectively connecting a negative voltage to the inverter output, and ohmic resistance means coupled in parallel to the inverter output, a controller for selectively switching the first and second switching means with a switching frequency to produce an AC voltage from the positive and negative voltage, wherein the controller is adapted to alter the duty ratio of the switching frequency to adjust the symmetry of the AC voltage produced by the inverter.

Abstract: The invention relates to an inverter for converting a DC voltage into an AC voltage having one or more phases, comprising an intermediate DC circuit having a first and a second DC capacitor unit connected in series between a first and a second terminal of the intermediate DC circuit, and a common earth terminal of the intermediate circuit, and at least one subcircuit for generating one phase of the alternating voltage, each subcircuit comprising: a first and a second auxiliary switch, each with a diode connected in parallel, an AC node for supplying a pulsed voltage, the first and second auxiliary switches being connected in series between the common earth terminal of the intermediate circuit and the AC node and the diodes of said power switches being connected to each other with opposite forward directions, and each of the subcircuits comprises two power switches, each with a diode connected in parallel, wherein said two power switches are connected in series between the first and second terminal o