Photovoltaic grid-connected and electric energy quality management unified control strategy

The invention discloses a photovoltaic grid-connected and electric energy quality management unified control strategy comprising the following steps that 1) photovoltaic component output is detected in real time, and the operation mode of a photovoltaic grid-connected system is adjusted; when the active grid-connected conditions are not met, the photovoltaic grid-connected system operates in an electric energy quality management mode, and when the active grid-connected conditions are met, the photovoltaic grid-connected system operates in an active grid-connected and electric energy quality management unified mode; and 2) when the photovoltaic grid-connected system operates in the active grid-connected and electric energy quality management unified mode, the photovoltaic grid-connected system allocates residual capacity of the photovoltaic grid-connected system according to priority of reactive power and harmonic compensation firstly and then integrates command current based on the instantaneous power theory. Compared with conventional methods, the photovoltaic grid-connected system is enabled to have a function of actively participating in power gird electric energy quality management on the basis of maintaining the original functions so that utilization rate of an inverter is enhanced, use of an electric energy quality management device is reduced and cost is saved.