Two-phase control method for hybrid clamped three-level photovoltaic inverter

The traditional control methods for hybrid clamped three-level photovoltaic inverter have the disadvantages of low DC voltage utilization, high switching loss and complex control. To solve the above problems, two-phase control method is adopted in this paper. This kind of method can allow one to maintain the balance of the midpoint potential automatically, to improve the voltage utilization for 15%, to reduce the switching loss for 1/3, and to simplify the control of system. Moreover, the designed system can be applied to any kind of load (linear or nonlinear) with any kind of connection (Y or Δ). To get better performance, FPGA is used as the main controller for its parallelism and rapidity. The validity of this method has been proven through simulation and experiment results in a hybrid clamped three-level three-phase inverter.