FOUR QUADRANT TRANSFORMER (VARIANT) Russian patent published in 2007 - IPC H02M7/219 H02P27/04 

FIELD: electric engineering, possible use as voltage transformer for powering alternating current electric machines.

SUBSTANCE: four quadrant transformer contains one-phased transformer, controllable semiconductor bridge, network inductor, smoothing capacitor and rejecter LC-filter. A load is coupled in parallel at the output of aforementioned bridge. Two additional network inductors may be installed in four-quadrant transformer serially with the network inductor. Nominal inductivity of first additional inductor does not exceed the nominal inductivity of the network inductor. Nominal inductivity of the second additional inductor does not exceed the nominal inductivity of the first additional inductor. Total inductivity of all inductors at maximal current has value not below the maximal inductivity of the network inductor. Connection of additional network inductors to the main network inductor and to semiconductor bridge is realized by contacts of bipolar two-positional switch. Additional network inductors may be connected to the main inductor in parallel via the existing normally open key. In that case, the nominal inductivity of one additional inductor is below the nominal inductivity of the network inductor, and the nominal inductivity of the second additional inductor is below the nominal inductivity of the first additional inductor.

EFFECT: increased efficiency of the four-quadrant transformer due to reduced energy losses in network inductors, simplified voltage control due to setup of operation with linear and more monotonous dependence of voltage drop in inductance of input circuit on the load current.

2 cl, 5 dwg