Nonlinear pulse width modulation control device of single phase current source grid connected inverter
The invention relates to a nonlinear pulse width modulation control device of a single phase current source grid connected inverter. The device can be used for adjusting duty ratio in time and outputting high quality power grid current by feedback of modulation current, so as to effectively overcome the native defect of serious aberration of power grid current wave form when the traditional linear PWM control strategy is adopted; a control circuit of the device comprises an integrating circuit having high frequency resetting function, an absolute value circuit I, a comparison circuit, a RS trigger, a combinational logic circuit as well as a reference sinusoidal current circuit, an absolute value circuit II, a zero crossing comparison circuit and a constant frequency clock circuit that have fixed phase relationship with the power grid voltage. The nonlinear pulse width modulation control device can lead unstable DC voltage to be converted into stable grid connected current with the needed magnitude and high quality, and has the advantages of single stage power conversion, high conversion efficiency, small harmonic wave of the grid connected current, rapid dynamic response, high reliability when in overloading, low cost and the like, so as to establish key technology for a renewable energy source grid connected power generation system.