The quasi-Z-source inverter（QZSI） applied to the photovoltaic（PV） system has nonlinear and unstable zero dynamic characteristics

which leads to the problem of system oscillation

slow dynamic response and complex controller design. Thereby

we propose a nonlinear control strategy based on Input-output Linearization for QZSI. The affine nonlinear model of the QZSI DC-side is presented and transformed to a linearized form with the help of input-output feedback linearization technique. Based on the linearized system

simple linear controllers are employed to regulate the input voltage of the QZSI

and finally achieve maximum power point tracking. Moreover

the input/output linearization modeling method for the quasi Z-source inverter is described. The zero dynamic stability of the linearized system is proved by theoretical deduction. The DC-side and AC-side controller of the quasi Z-source inverter are designed to realize the three targets of boosting the PV inverter and controlling the grid-connected waveform and the power. Through simulation and experiment

compared with classical control strategy

it is shown that this control method can make QZSI input voltage to track the maximum power point fast

and guarantee the quality of input voltage and grid-connected current waveform when the operation point of the system changes in a wide range.