Multi-inversion-unit parallel connection based photovoltaic inverter control method

The invention discloses a multi-inversion-unit parallel connection based photovoltaic inverter control method. A photovoltaic inverter control method comprises N parallel connection modules or inversion units. The multi-inversion-unit parallel connection based photovoltaic inverter control method comprises the following steps of (1) detecting the inverter general output power Ps and the number M of opened modules or inversion units; (2) when M is larger than or equal to N, enabling the modules or the inversion units to work at a power point which is corresponding to a ratio between Ps and N and executing a step (3) if not; (3) opening corresponding modules or inversion units which are corresponding to head elements in an unopened queue Q1 if the photovoltaic inverter general output power Ps is larger than M*eta*Pe when M is larger than or equal to 0 and smaller than N and executing a step (4) if not; (4) closing the modules or inversion units which are corresponding to the front elements in queue Q2 of the opened modules or inversion units of the photovoltaic inverter general output power Ps is smaller than or equal to (M-1)*eta*Pe when M is larger than or equal to 1 and ending control if not. The multi-inversion-unit parallel connection based photovoltaic inverter control method has the advantages of being simple in principle and easy to achieve, reducing the system loss, improving the inverter conversion efficiency and the like.