A Reactive Power Distribution Method for the Reactive Power Control of Cascaded Photovoltaic Converter under Active Power Imbalance Condition

Two-stage photovoltaic cascaded converters have significant advantages, such as higher efficiency and lower cost, but active power imbalance limited its application. An efficient way to handle the power imbalance issue is to inject reactive power into the system with the proper distribution. In this paper, a reactive power distribution method that can assure the balance of the apparent power of modules to the maximum extent is studied. The principle of distribution as well as the equation to calculate the reactive power of each module are brought up. Experiments are also carried out to prove the effectiveness of the distribution method.