| 摘要 |
In a circuit apparatus for transformerless conversion of an electric direct voltage of a two-pole direct voltage source ( 1 ) connected to ground having a first voltage pole (+) and a second voltage pole (-) into an alternating voltage, hazardous capacitive leakage currents are avoided by connecting the direct voltage source ( 1 ) to ground and the DC-AC converter ( 400 ) is operated at a controlled intermediate circuit voltage, a DC-DC converter stage ( 300 ) being connected between the direct voltage source ( 1 ) and the DC-AC converter ( 400 ), said DC-DC converter stage providing at its output a +/- voltage that is symmetrical with respect to the grounding point, two series-connected capacitors ( 41, 42 ) having the same polarity and being connected to ground at their connecting point (V) and controlled are charged by two buck-boost choppers ( 100, 200 ) connected one behind the other.
|
