The invention discloses a direct 
power control method for inhibiting 
voltage fluctuation of a DC-side 
bus of a photovoltaic grid-connected 
inverter, and belongs to the technical field of converter control. The method comprises the steps of establishing a 
photovoltaic power generation system, determining instantaneous 
active components v<alpha> and i<alpha> and instantaneous 
reactive components v<beta> and i<beta> of a 
power grid, realizing the 
maximum power point tracking of a photovoltaic array by adopting a fixed-step 
perturbation and observation method, determining the disturbance power Pswith a short wavy line thereon by a 
disturbance observer through a correction link; respectively taking output signals [nu]<^>P and [nu]<^>Q of two PI controllers as the input of a feedforward 
decoupling controller to construct a feedforward decoupling model, obtaining 
voltage control signals e<alpha> and e<beta> by combining the output uP and uQ of the feedforward decoupling 
system based on 
voltage v<alpha> and v<beta> of the 
power grid, and carrying out [alpha][beta] / abc conversion on the 
voltage control signals e<alpha> and e<beta> to obtain an SPWM 
control signal e<a, b, c> of the 
inverter. According to the invention, the feedforward disturbance is introduced into the voltage outer loop, and the zero steady-state error tracking of the 
DC bus voltage can be ensured by adopting a simpleproportional controller; it does not need to obtain phase information of the 
power grid voltage and does not need to perform synchronous rotation coordinate transformation, so that the stability problem caused by the use of a phase-looked loop (PLL) is avoided.