Method and apparatus for controlling alternating current cascade photovoltaic power generation system

An apparatus for controlling an alternating current cascade photovoltaic power generation system, wherein the apparatus comprises a master controller and a slave controller, the master controller comprises an acquiring module, a first determining module, a generating module and a first control module, and the slave controller comprises a receiving module and a second control module, and wherein:

• the acquiring module is configured to acquire a current total output power of the alternating current cascade photovoltaic power generation system;
• the first determining module is configured to determine whether the total power value is greater than a preset power value;
• the generating module is configured to generate a first control signal if the total power value is greater than the preset power value, or generate a second control signal if the total power value is smaller than or equal to the preset power value;
• the receiving module is configured to receive the first control signal or the second control signal generated by the master controller;
• and
• the first control module and the second control module are configured to control, based on the first control signal, a cascade unit connected to the slave controller to independently perform a maximum power point tracking (MPPT) operation, or control, based on the second control signal, the cascade unit connected to the slave controller to output power.