Patent ID: 8189352
Filing Date: 2012-05-29
Classification: G05F,Y02E,Y10S

Abstract:
1. A single stage inverter device, for converters of power from dc energy sources to an electric ac network or grid having at least one phase, of pulsation frequency ω grid , comprising switching means capable to periodically connect, with period T s lower than the period T grid corresponding to the pulsation frequency ω grid , a source, capable to output a voltage v g (t) of average value V g , to the grid so that the device output current i 0 (t) is in phase with the voltage v 0 (t) of at least one phase of the grid, the maximum value of which is V o,max , the switching means being controlled by controlling electronic means operating according to a control over a single switching cycle of the switching means, the device seeing an output inductance L, the device comprising a sensing resistor of resistance R s connected in series to the grid, the controlling electronic means comprising: a resettable integrator circuit having a time constant τ such that τ<T comparator means, capable to output a signal indicative of the comparison of a voltage drop [R generator means capable to receive the output signal from the comparator means and a signal indicative of the phase of the grid for providing one or more signals for controlling the switching means, the control voltage V wherein the device fulfils a second constraint whereby the input signal of the integrator circuit is always positive, and it fulfils a third constraint whereby, at any time instant, the input voltage of the switching means is higher than the output voltage thereof, and it fulfils a fourth constraint whereby where: P P α is a first coefficient of overload, with α≧1, and γ is a second coefficient, with γ<1.