Dc bus voltage control for two stage solar converter

A system for supplying AC power to an AC power grid from a DC power source, comprising:

• a boost converter coupled to the DC power source;
• a DC bus coupled to said boost converter, said boost converter providing DC power to said DC bus;
• an inverter coupled to said DC bus, said inverter configured to convert the DC power of said DC bus into AC power based at least in part on a modulation index;
• a monitoring system comprising a DC bus voltage sensor and an output AC current sensor, said DC bus voltage sensor providing a DC bus voltage feedback signal based on the DC bus voltage, said output AC current sensor providing an output AC current feedback signal based on the output AC current of said inverter;
• and,
• a control system configured to control the DC bus voltage to be substantially equal to a variable DC bus voltage setpoint, said control system configured to adjust the variable DC voltage setpoint based at least in part on the DC bus voltage feedback signal and the output AC current feedback signal so that the modulation index of said inverter remains substantially constant.

A method for controlling a DC bus voltage in a system for providing AC power to an AC power grid from a DC power source, said method comprising:

• providing DC power to a DC bus at a DC bus voltage;
• converting the DC power on the DC bus to AC power with an inverter coupled to the DC bus, the inverter having an output AC current;
• controlling the DC bus voltage to be substantially equal to a DC bus voltage setpoint;
• and,
• varying the DC bus voltage setpoint based in part on an output AC current of the inverter.