Abstract: The AC voltage sensors are used to measure the grid voltage，which brings high hardware cost，

difficult installation and low reliability. In order to realize that grid voltage sensors are not necessary，virtual flux

was introducted to model prediction power control algorithm for cascaded H-bridge rectifier. The virtual flux space

vector was obtained by integrating the voltage vector taking a single-phase seven-level rectifier as an example. The

first-order low-pass filter was usually used in the integration to solve initial value problem and DC offset problem.

Aiming at solving phase shift，the phase compensation method was proposed and applied to the first-order low-pass filter estimating the virtual flux of grid voltage. For balanced DC voltage between modules of H- bridge rectifier，the DC voltage balanced control method based on voltage feedback by adjusting duty ratio was used. The

experimental results show that the proposed algorithm is correct and effective.

      Key words: virtual flux（VF）；phase compensation；model prediction power control；voltage balance