VOLTAGE TRANSFORMER Russian patent published in 2008 - IPC H02M7/538 

FIELD: transformation equipment engineering, possible use primarily in power supplies for electric welding.

SUBSTANCE: voltage transformer, containing inverter block with two inverters, made primarily according to semi-bridge circuit with power capacitors and with power transistors, connected serially pair-wise, to power electrodes of each one of which a resonance capacitor is connected in parallel, and to outputs of inverter block electromagnetic unit is connected with two transformers, where their magnetic conductors are made with a gap and contain one input and two output windings each, where two inverters are connected in parallel by power inputs and connected serially by outputs of alternating current by opposite connection of their transformers to input windings and also creation of two pairs of output windings, connected serially in matched fashion and connected to their respective rectifier diodes and to filter in anti-phased manner, and points of connection of power transistors of both inverters are interconnected through auxiliary inductance. Claimed transformer features reduction of dynamic power losses due to ensured soft commutation of transistors with zero voltage at corresponding resonance capacitor. This is achieved by ensured accumulation of required energy in additional inductance in case of low load currents, in inductance of magnetizing contour and transformer dissipation inductance - in case of average current value and dissipation inductance - in case of nominal load current. Roles of aforementioned inductances are redistributed automatically with alternation of load current, and conditions are created for resonance and soft commutation.

EFFECT: reduced dynamic losses in transistors due to ensured conditions for soft commutation during change of load current.

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